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The invention relates to installations for diffusing a mist of nebulized water droplets onto products.
Such an installation, associated for example with a food product exhibition display used in a place of sale, is known from the document WO-2010/106276 in the name of the applicant. The installation comprises diffusers which project the mist over the products. It preserves the freshness of the products, enhances their appearance on the display stand and promotes their sale.
The installation notably comprises a mast with a stopper at its top end. The stopper has internal pipes coinciding with orifices of the mast in order to connect them with the bottom part of the mast and thus allow the outward diffusion of the mist of droplets originating from the bottom part of the mast. If the stopper is turned, the coincidence is eliminated such that the orifices are blocked and the diffusion is stopped.
Despite its many advantages, such a stopper offers little flexibility in adjusting the diffusion of the mist onto the products. Furthermore, it is relatively costly to produce because of its bulky nature.
One aim of the invention is to adjust the diffusion of the mist onto the products in a more flexible manner and reduce the cost of the installation.
To this end, there is provided, according to the invention, a mist diffusion head for a nebulizing installation, which exhibits
a mist inlet orifice, and at least two mist outlet orifices each suitable for connecting the inlet orifice with the outside of the head,
the head comprising at least two shutters suitable for blocking the respective outlet orifices, each shutter being able to block just one of the outlet orifices, the shutters being mounted to move relative to a frame of the head independently of one another.
Thus, each of the orifices can be blocked or opened independently of the other(s). The choice of the number of open orifices makes it possible to adjust the quantity of mist diffused onto the products. Also, the possibility of opening one orifice rather than another makes it possible to orient the diffusion of the mist in the desired direction, for example toward certain products and not toward others. This adjustment can be easily modified at any time by blocking some of the orifices and by opening others. The head according to the invention therefore offers great flexibility in adjusting the intensity of the mist flow or flows and their orientation.
The head according to the invention will also be able to exhibit at least any one of the following features:
the shutters are mounted to rotate relative to the frame; each shutter exhibits a vertical axis of rotation; each shutter exhibits a horizontal axis of rotation; the shutters have the same axis of rotation; and the shutters are mounted to slide relative to the frame, notably in a direction parallel to a main axis of the head.
Advantageously, the head is arranged such that each shutter tends by gravity to occupy a predetermined single position out of an orifice blocking position and an orifice opening position, preferably the blocking position.
The control and use of the head are thus simplified. It is in fact sufficient for the operator to place the shutter in the vicinity of the predetermined position for it to reach said position and stably remain there.
In one embodiment, the head comprises magnets suitable for retaining the respective shutters in a predetermined position, preferably a position of opening of the orifice by the shutter.
The magnets form a simple and non-mechanical means for retaining the shutters in the predetermined position.
Advantageously, each shutter extends inside the head and comprises an operating member extending outside the head.
The operator can therefore act directly on the shutter to place it in the desired position, and do so without having to open the head.
Preferably, each shutter passes through an orifice of a cover of the head.
Forming additional openings in the main wall of the head is thus avoided.
Provision can be made for the head to comprise two walls defining the orifices, extending one against the other, between which the shutters are interposed and configured to guide the shutters.
Provision can also be made for the head to comprise an internal dispenser distinct from the frame and suitable for connecting the inlet orifice with the outlet orifices.
Since it is distinct from the frame, this dispenser can easily be removed to be cleaned. Furthermore, since the dispenser can be a part that is hidden from view, its constituent material can be chosen freely, notably without constraint associated with the appearance of this material.
Advantageously, there are at least three outlet orifices.
Preferably, the outlet orifices are external orifices.
There is also provided, according to the invention, an installation for diffusing a mist of droplets which comprises at least one head according to the invention.
There is also provided, according to the invention, a method for diffusing a mist of droplets onto products, in which at least one head according to the invention and/or at least one installation according to the invention are/is used.
There follows a description of a number of embodiments of the invention by way of nonlimiting examples, and with reference to the attached drawings in which:
FIG. 1 is an overview of an installation according to a first embodiment of the invention;
FIGS. 2 to 4 are perspective views of the head of the installation of FIG. 1 ;
FIGS. 5 and 6 are perspective views of one of the shutters of the head of FIG. 2 ;
FIG. 7 is a view similar to FIG. 2 shows an intermediate position of opening of the orifices;
FIGS. 8 to 12 are views similar to FIGS. 2 to 6 , illustrating a head according to a second embodiment of the invention;
FIGS. 13 to 16 are views similar to FIGS. 2 to 6 illustrating a head according to a third embodiment of the invention;
FIGS. 17 and 18 are perspective views of a head according to a fourth embodiment of the invention;
FIGS. 19 to 22 are perspective views of different parts of the head of FIG. 18 ; and
FIG. 23 is a view similar to FIG. 18 showing a step of assembly of the head.
DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a food product presentation installation 2 . Here, it is a piece of furniture in this case forming a table. In the present example, this piece of furniture is used in a place selling products.
The products are for example fresh products 5 such as fruit and vegetables. The installation can also be used for other fresh food products such as meat or fish. It is also applicable to food products such as cheese and, more generally, to any product sensitive to drying, such as flowers.
The piece of furniture here forms a display stand and comprises, in the top part, a planar rectangular display 6 . The display stand comprises a bottom wall and is open in the top part such that the products can be observed or taken by the public passing alongside the display stand.
The piece of furniture comprises means for diffusing a mist of nebulized water droplets, over the products and onto the latter in order to preserve their freshness. These means comprise a vertical mast 14 of axis 19 and an equipment item 8 making it possible to generate the mist of water droplets and route it to the mast. This equipment item notably comprises an electrical power supply unit which supplies current to a mist generator. The latter comprises one or more ultrasound emitters equipped, for example, with an acoustic concentration nozzle used to produce the mist formed by the nebulized water droplets in suspension in a flow of air. The generator is fed with water by a suitable means. Such a generator is known in itself notably from the document FR-2 788 706. The installation comprises pipes 12 by means of which the mist produced by the generator or generators is transmitted to the mast, to a bottom axial end thereof. The assembly is provided with a control unit which is not illustrated and that makes it possible to control and adjust the operation of the piece of furniture. The unit notably makes it possible to adjust the ventilation speed, that is to say the speed of the air forming a part of the mist, the nebulizing power and other machine parameters (cycle, safety threshold, etc.).
The installation comprises a head 16 situated at the top of the mast and ensuring the diffusion of the mist toward the products, the head being situated higher than the latter.
For the simplicity of the description, the installation here comprises a single mast 14 bearing a single head 16 . It is however understood that such an installation can comprise a plurality of masts each bearing a diffusion head.
There now follows a description of several embodiments of the head 16 . In these different embodiments, similar elements have numerical references increased by 100.
First Embodiment
A first embodiment of the head 116 is illustrated in FIGS. 2 to 7 .
The head is generally shaped with symmetry of revolution about the axis 19 . It comprises a body 120 , in this case formed by a bolus, the wall of which is, in cross section in a plane radial to the axis 19 , in the form of a circular arc, the center of curvature of which is located inside the bolus. The bolus is flared and curved, its diameter widening from the base of the bolus to its top edge. Here, this form divides by six the speed of the mist between its inlet and its outlet from the head, by creating an expansion of the mist, and makes it possible to downwardly orient the orifices 18 of the bolus presented below.
The bolus 120 has, at its bottom end, a flange 122 by which it is threaded onto the top end of the mast with the head coaxial to the mast. This flange delimits a bottom mist inlet orifice 15 in the head for the mist from the mast.
The bolus 120 has a top circular opening extending in a plane at right angles to the axis 19 and blocked in a seal-tight manner by a removable cover 124 having a flange fitted into the opening of the bolus.
The bolus has external mist outlet orifices 18 passing right through its wall from the outside to the inside of the bolus. Here, there are six of these orifices, but this number can be varied and can, for example, be equal to two, three, four or five or even more than six. The orifices are, in this case, identical to one another and evenly distributed around the axis 19 by being the image of one another by a rotation of the axis 19 . Each orifice is here oblong, slotted, stretching vertically in a direction contained in a plane radial to the axis 19 . The axis of each orifice is inclined relative to the vertical and horizontal directions. The bolus delimits an internal cavity 17 of the head. Each orifice 18 connects the inlet orifice 15 with the outside of the head via the common cavity 17 , and does so independently of the other orifices 18 .
The head 116 comprises shutters 126 associated with the respective outlet orifices 18 and equal in number thereto. The shutters are suitable for blocking the respective outlet orifices, each shutter being suitable for blocking just one of the outlet orifices. The shutters are identical to one another. They are mounted to move relative to the bolus independently of one another. In this case, the shutters are mounted to rotate relative to the bolus around the same vertical axis formed by the axis 19 .
Each shutter 126 comprises a stopper 128 extending inside the head and an operating knob 130 extending outside the head.
The cover has a bottom flange having external and internal cylindrical faces with circular section in a plane at right angles to the axis 19 . In this flange, circumferential radial through-openings 132 are formed, in the same number as the shutters, and respectively receiving the latter. The openings 132 are opened downward at the bottom edge of the cover coming into contact with the upper edge of the bolus and each have a general rectangular form.
Each shutter extends through one of the openings, the area of join between the stopper and the knob extending into the opening. The area of join also comprises an internal guiding portion 133 having a cylindrical external face 134 with circular section in a plane at right angles to the axis 19 and of the same radius as the internal face of the flange of the cover so as to produce a surface contact therewith. The knob 130 , moreover, comes to bear by its internal face against the external face of the flange.
The cover 124 comprises a disk-shaped internal wall 136 , extending facing the external wall of the cover and rigidly fixed thereto by conventional means allowing it to be removed, for example screws 144 extending into orifices of the internal wall and engaged with corresponding threads of the main external wall of the cover. The orifices of the wall 136 have a shoulder onto which the head of each screw comes to bear. The internal wall 136 has a cylindrical circumferential face 138 of circular section in a plane at right angles to the axis 19 which is suitable for producing a surface contact with an internal face 140 of the same form of the guiding portion 133 . These cooperations ensure the rotational guidance of each shutter relative to the cover about the axis 19 .
The portion 133 and the knob 130 each have a height in the direction of the axis that is greater than that of the opening 132 . Similarly, the portion 133 has a length in the circumferential direction about the axis that is greater than that of the opening. Furthermore, the guiding portion 133 has a top flange 142 coming to bear against an internal top face of the wall 136 . By virtue of this arrangement, the shutters are kept captive in the openings 132 , even when the cover is separated from the bolus.
Each knob 128 has an external face in surface contact with the internal face of the bolus and suitable for blocking all of the associated orifice 18 . This is the blocking position occupied by the shutter when it is in abutment against one of the circumferential ends of the opening 132 . For the shutters that can be seen on the front face of the head in FIG. 3 , this is the left end of the opening 132 . Conversely, when the shutter is in abutment against the other circumferential end of the opening, the stopper leaves the orifice 18 entirely free. The shutter is then in the open position, at the right end of the opening in FIG. 3 .
The installation operates as follows. The mist generator produces a mist of nebulized water droplets in suspension in a flow of air which is routed from bottom to top in the mast 14 to the inlet orifice 15 then enters into the cavity 17 of the head as indicated by the dotted line arrows of FIG. 2 . The mist then leaves the head through only those outlet orifices 18 whose shutters are in the open position. The mist does not leave through the outlet orifices whose shutters are in the blocked position. Knowing that the orifices are distributed all around the head, it is thus possible to select the desired direction or directions in which the mist is to be diffused and therefore the area or areas of the display intended to receive the mist. At any time, one of the knobs 130 can be operated to place the shutter in the open or closed position, and this can be done independently of the other shutters. It is also possible to place all the shutters in the open position in order for the mist to be diffused at the same time through all the outlet orifices 18 . Conversely, all the outlet orifices can be blocked with the shutters to prevent any diffusion of the mist through the head, and for example reserve this diffusion for another head of the same installation.
As illustrated in FIG. 7 , it is also possible to place at least any one of the shutters 126 in an intermediate position of opening of the associated orifice. In this case, this intermediate position can be any position between the fully open position and the fully closed position. The shutter is retained there by friction. In such an intermediate open position, the flow rate of the mist through the orifice is overall proportional to the section of the orifice which is thus left free by the shutter. The knobs 130 , which have a flattened form in a vertical plane radial to the axis 19 , are particularly easy to manipulate.
By virtue of the shape given to the bolus and to the shutters, if condensation occurs inside the head, notably on the shutters, no drop of water flows out of the head. The flow takes place entirely within the head and inside the mast.
Second Embodiment
There now follows a description, with reference to FIGS. 8 to 12 , of a second embodiment of the head 216 of the installation of FIG. 1 . The head 216 is similar to that of the first embodiment. It differs therefrom by the shape of the openings 232 which, here, is not rectangular but oblong. Furthermore, these openings 232 are this time closed on the side of the bottom edge of the cover. The knob 230 of each shutter 226 is this time in the form of a rectilinear rod extending in a direction radial to the axis 19 . This rod extends through the opening 232 to constitute the part of the shutter which is housed therein. The guiding portion 233 of the shutter has no flange. Therefore, this time, it is the rod 230 received in the opening 232 which keeps the shutter captive in the cover. The other features of the head are identical to those of the first embodiment. The operation of the installation is unchanged.
Third Embodiment
There now follows a description with reference to FIGS. 13 to 16 of a third embodiment of the head of the installation of FIG. 1 . It differs from that of the first embodiment by the following features.
This time, the axis of rotation 346 of each shutter 326 is horizontal and locally parallel to the direction tangential to the flange of the cover. The axes of rotation 346 of the shutters are not therefore parallel to one another but all extend in one and the same plane at right angles to the axis 19 .
In these conditions, whereas in the previous two embodiments the stoppers remained in contact with the internal face of the bolus regardless of their position, this time the stoppers are in contact with this face only in the blocking position. The stoppers are separated from the face in the open position. In this case, each stopper in the open position extends facing the cover and even in contact therewith. The internal wall of the cover is, this time, absent.
The holding of the stoppers in the open position is ensured by magnets 348 of which, here, there are as many as there are shutters. The magnets 348 are in this case rigidly fixed to a bottom face of the cover. Each shutter comprises at least one part made of magnetic material suitable for cooperating magnetically with the magnet.
Each shutter is arranged such that it tends by gravity to occupy just one position out of the blocking position and the open position of the orifice. Here, it is the blocking position which is therefore a stable position. If necessary, a counterweight can be added to each shutter to obtain this effect, if it is not already obtained by the weight distribution of the shutter given the position of its axis of rotation.
Each magnet is chosen such that it is not sufficient in itself to displace the shutter from the bottom blocking position to the top open position. On the other hand, it is chosen such that it is able to keep the shutter in the latter position when the operator places it there by actuating the knob 330 or places it is an adjacent position. The knob this time has a form that is flattened in a direction radial to the axis 19 when the shutter occupies the blocking position.
Each shutter can be produced entirely in a metallic material suitable for cooperating with the magnet. Otherwise, it is possible to produce a part of the shutter in a non-magnetic metallic material or even in a plastic material, and another part of the shutter, comprising the knob, in a metallic material suitable for cooperating with the magnet.
The operation of the installation is identical to that of the preceding embodiments, each shutter making it possible, at will, to open or close the associated outlet orifice 18 .
To remove the cover from the bolus, all the shutters are placed in the open position such that they are retained magnetically against the cover and are thus rigidly fixed thereto.
In each of these embodiments, the bolus and the cover can be made of a plastic material or of metal, for example stainless steel, possibly non-magnetic.
Fourth Embodiment
A fourth embodiment of the head 416 is illustrated in FIGS. 17 to 23 . It is identical to the first embodiment except for the following.
The body this time comprises a cylindrical external wall 420 , the generatrices of the cylinder being based on a half-circle. The axis 19 of the cylinder is vertical and forms the main axis of the head.
The body has, at its bottom end, an end fitting 422 by which it is threaded coaxially onto the top end of the mast 14 . This flange delimits the inlet orifice 15 . The body comprises a planar bottom wall 423 at right angles to the axis 19 and contiguous to the top edge of the end fitting 422 in line with which it presents an orifice. It also comprises a rectangular planar rear wall 425 parallel to the axis 19 , contiguous to the rear edge of the bottom 423 and in contact by its longitudinal ends with the internal face of the wall 420 .
As illustrated notably in FIG. 19 , the body has external mist outlet orifices 18 passing through the wall 420 . Here, there are three of these orifices. Each orifice this time has a circular form extended by an oblong section stretching vertically upward. Each orifice 18 connects the inlet orifice 15 with the outside of the head via the common cavity 17 , and does so independently of the other orifices 18 .
Referring notably to FIG. 22 , the shutters 426 are mounted to slide relative to the body in the vertical direction, that is to say parallel to the axis 19 . Each shutter 426 comprises a stopper 428 extending inside the head and an operating knob 430 extending outside the head. The stopper 428 in this case has a flattened rectangular parallelepipedal form with rounded corners. The knobs 430 have a form that is flattened in a vertical plane radial to the axis 19 .
The head 416 further comprises an internal part 450 in this case formed by a dispenser. It is intended to extend in the head by being in contact with the internal faces of the walls 420 , 423 and 425 . For this, the dispenser comprises a vertical rectangular planar rear wall 452 intended to be in surface contact with the wall 425 and a cylindrical wall 454 intended to be in surface contact with the internal face of the wall 420 . It also comprises a planar top wall 456 , the edges of which are contiguous to those of the walls 452 and 454 , these three walls forming a chamber that opens downward in line with the wall 456 . This bottom opening is pressed against the bottom 423 and thus connects this chamber with the mast 14 .
The cylindrical wall 454 has three identical circular orifices 458 . When the dispenser 450 occupies its operating position in the head, the orifices 458 coincide with the respective orifices 18 .
Furthermore, the wall 454 has, on its external face, three identical rectangular slide rails 460 forming thinned areas of this wall. The slide rails emerge at the bottom edge of the dispenser. The orifices 458 extend to the center of the corresponding slide rails. The width of the slide rails corresponds to that of the stoppers 428 . The height of the slide rails is very much greater than that of the stoppers. This way, the respective stoppers can be received in the slide rails by being guided therein to slide vertically relative to the dispenser. Each slide rail is sufficiently deep in the radial direction for the external face 434 of each stopper not to extend beyond the enclosing surface of the external face of the cylindrical wall 454 . This mounting is therefore compatible with the surface contact of the walls 454 and 420 apart from the slide rails. The shutters 426 are thus interposed in the direction radial to the axis 19 between the dispenser 450 on the inside and the wall 420 on the outside. Each knob 430 emerges through the oblong extension of each orifice in order to make it possible to control the position of the stopper from the outside of the head. By virtue of this arrangement, the shutters 426 are kept captive in the head.
Each shutter 426 can therefore occupy a top position, illustrated notably in FIGS. 17 and 23 , in which it leaves the corresponding orifice 18 entirely free. It can also occupy a bottom position, illustrated notably on the left in FIG. 17 , in which it completely blocks the corresponding orifice. These two positions form the two ends of the sliding travel of the shutter. The shutter can also be placed in any position between these two ends by being immobilized there by friction in contact with the two parts between which it is interposed.
To facilitate the sliding of each shutter against the dispenser, it is possible to provide for the external face thereof to be covered with a material such as polytetrafluoroethylene.
The head 416 can be assembled as follows with reference to FIG. 23 . The first step is to introduce the shutters 426 into the head to place them in the respective orifices 18 and in abutment against the internal face of the wall 420 . The dispenser 450 is then inserted into the head through the top thereof until it is placed against the bottom 423 . In this position, it connects the mast 14 and the end fitting 422 with the orifices 458 , then the orifices 18 when the latter are left free by the shutters. In the present example, two screws 460 pass through the wall 425 and come to bear against the dispenser to immobilize it.
The operation of the head is similar to that of the preceding embodiments.
Of course, numerous modifications can be added to the invention without departing from the framework thereof.
Provision can be made for the magnets to be intended to keep the shutters in the closed position. The magnets can be placed on the shutters and not on the frame of the head.
The installation does not necessarily form a piece of furniture. It can be used in a place of storage or of production, for example a place where wine is made or cheeses are ripened. It can constitute a production and/or packaging installation. The installation can also be used to disinfect or humidify products or volumes, for example products circulating on a belt, notably on a production or packaging line.
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A fog distribution head for a fogging apparatus, which has: a fog inlet, and at least two fog outlets, each suitable for placing the inlet in communication with the outside of the head. The head includes at least two plugs suitable for plugging the respective outlets. Each plug is suitable for plugging a single one of the outlets, the plugs being movably mounted with respect to a frame of the head, independently from one another.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
FEDERAL SPONSORSHIP
[0002] Not Applicable.
BACKGROUND
[0003] The invention uses different silicone devices in cooking. Silicone is ideal for use in cooking because it maintains its flexibility over a wide range of temperatures, from freezing to high temperature cooking, without breaking down. Unlike rubber-based products, silicone is inert and imparts no flavor or residue to food. The silicone devices are easy to learn to use, and easy to use. They can be stretched to hold and support a variety of foods for a variety of food preparation purposes.
[0004] Cooks and chefs use many different devices to secure meat, poultry, fish, vegetables and other food before and during the cooking process. For example, a lamb shank or osso bucco must be tied before braising. Vegetables, for example leeks, are often bundled before cooking. Typically the food item is tied with twine or string prior to cooking. Twine is used because meat tends to fall apart and fall away from the bone as it cooks. The twine holds the meat in place. However, it takes time to tie each food item. And, it takes time to train new chefs how to properly tie food. The silicone devices are easy to learn to use and easy to use. They may be quickly stretched and placed over the food item, removing the need for tying. Saving time is especially important in the restaurant business. The silicone bands save time both in chef training and during day-to-day operations.
[0005] During cooking, twine absorbs juices and oils from the food. The twine and meat will frequently interact and the twine will stick to the food. The twine also may assume the color of the food. After cooking is complete, chefs typically cut and remove the twine from the meat prior to serving. However, it is often difficult to find and remove the twine after cooking because the twine has become colored with and enmeshed with the food. Rubber-based products cannot be used because rubber breaks down at temperature, and may impart foul tastes or toxins to the food.
[0006] In addition, twine or string is not optimal for grilling because it may catch on fire during grilling. Currently, when grilling meat chefs use skewers or toothpicks. When grilling vegetables chefs typically soak the twine in water, then tie the twine around the vegetables prior to cooking. The silicone devices are inflammable. There is no need to soak them in water prior to grilling, and the silicone bands may be placed on the food without tying.
[0007] Previous attempts have not solved these problems. U.S. Pat. No. 3,823,442 teaches that an elasticized band covered with tightly woven fabric may be used to hold meat during cooking. However, the fabric covering interacts with the cooking meat and will stick to the meat, making removal of the fabric bands difficult. U.S. Pat. No. 6,308,617 teaches the use of a machine for binding roasts with elastic rings. However, the use of a machine is cumbersome and can only be used for roasts.
[0008] Neither of these patents suggest that chefs use silicone devices to rapidly prepare food and to support the food during cooking. Neither of these patents combine the time-saving features of silicone devices with the non-stickiness of the silicone devices.
[0009] The prior art also discloses a number of devices that may be used to retain poultry hocks during cooking. For example U.S. Pat. No. 3,895,415, U.S. Pat. No. 4,056,865, U.S. Pat. No. 4,056,865, U.S. Pat. No. 5,112,274, U.S. Pat. No. 5,279,519, U.S. Pat. No. 5,735,736, U.S. Pat. No. 5,749,778, and U.S. Patent application No. 2003/0186640 all teach a variety of devices that may be used for retaining poultry hocks during cooking. Many of these devices are complicated and difficult to position on the poultry hock, and are similarly difficult to remove once cooking is complete. Rather than using any of these devices, the silicone string, bands or silicone connected double-O may be quickly and easily placed around the poultry hock prior to cooking and, after cooking is complete, quickly released without sticking to the food item.
[0010] In addition, chefs frequently use cheesecloth when poaching fruit, or other foods. The cheesecloth is typically wrapped around the food to prevent the food from losing shape, settling and touching each other during cooking. However, cheesecloth, like twine, frequently sticks to the food and is difficult to remove after cooking is complete. The silicone mesh or silicone perforated sheets can be wrapped around the food and will function like cheesecloth. However, the silicone mesh will not interact with the food and is easily removed after cooking.
[0011] Chefs also use polyethylene, polyvinylidene chloride, vinyl, or other similar wrap, especially when preparing food that is frozen and cooked later. However, polyethylene, polyvinylidene chloride, vinyl, or other wrap breaks down when exposed to heat and may impart residues to the food. Many of these wraps are not indicated for direct contact with food. In addition, these wraps cannot be used in ovens. The silicone film may be used any circumstances in which polyethylene, polyvinylidene chloride, vinyl, or other similar wrap is used, and in the oven. The silicone film may have direct contact with food, remains inert during cooking, and will not break down during cooking.
SUMMARY OF THE INVENTION
[0012] The invention uses a variety of silicone devices for food preparation and for cooking. Silicone is approved for use with food. Unlike many types of elastics, rubbers, and other compounds, silicone will not react with food during cooking. Silicone is inert even at very high temperatures. The silicone devices are easy to use. They may be quickly placed on the food prior to cooking and may be used to help the food retain its shape during cooking. Silicone will not stick to food even after thorough heating. Therefore, the silicone devices are quickly and easily removed after cooking.
[0013] The silicone devices may be used during food preparation to hold or cover food that is to be frozen. The frozen food and silicone devices may be taken directly from the freezer and then exposed to heat during cooking. The silicone devices will retain elasticity and will not react with the food.
[0014] The silicone devices may be used for food preparation even when the food is not cooked, or is pre-cooked. For example, caterers may use the silicone bands to pre-portion food prior to serving. The caterer may take the pre-portioned food, cut the silicone band, and place the food portion on the plate.
[0015] These features are important to the commercial cooking industry where saving small amounts of time on each food item can result in large costs savings to the restaurant, cafeteria or caterer. The ease of use of the silicone devices is helpful to the home chef, as well.
[0016] The silicone devices come in a variety of shapes for different uses: silicone string; silicone bands; silicone connected double-Os; silicone mesh; silicone perforated sheets; and silicone film. All of these devices may be reused, or they may be disposable. Optionally, the silicone devices may be brightly colored so that they can be easily seen and removed after cooking.
DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a plan view of a silicone band.
[0018] FIG. 2 is a cross-sectional view of silicone string.
[0019] FIG. 3 is a plan view of a connected double-O.
[0020] FIG. 4 is a plan view of silicone mesh.
[0021] FIG. 5 is a perspective view of a silicone perforated sheet.
[0022] FIG. 6 is a perspective view of a silicone film.
[0023] FIG. 7A is a side view of a silicone tube with two open ends.
[0024] FIG. 7B is a side view of a silicone tube with one open end.
[0025] FIG. 8 is a side view of the method of using silicone bands on a lamb shank.
[0026] FIG. 9 is a side view of the method of using silicone bands to close a poultry cavity.
[0027] FIG. 10 is a side view of the method of using the silicone mesh to poach fish.
[0028] FIG. 11 is a side view of the method of using the silicone perforated sheet to poach a pear.
[0029] FIG. 12 is a side view of the method of using the silicone file between lasagna and aluminum foil.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Silicone cooking devices have many advantages. Silicone is approved for use with food. See Title 21, Part 177, Section 2600 of the Code of Federal Regulations. Silicone is inert and will not react with food even at high temperatures. Depending on the formulation, silicone can be flexible; it can expand and contract as needed to accommodate positioning the silicone device on the food. Silicone retains its flexibility even at high temperatures and can accommodate food expansion and shrinkage during cooking. Silicone is non-stick and is typically easily removed from food after cooking is complete without causing the food to stick to the silicone device. Because the silicone devices are flexible, inert and non-stick, they may be sanitized and reused.
[0031] FIG. 1 shows a silicone band 10 . As shown in FIG. 8 , one or more silicone bands 10 may be positioned around a food item 12 , in this case a lamb shank. For use with a lamb shank, the inventor currently prefers using two or three silicone bands of approximately 3 inches diameter, and ¼ inch cross-sectional thickness. However, the silicone band may come in any variety of diameters and thicknesses, depending on the particular food and cooking technique used. As shown in FIG. 9 , a larger diameter silicone band may be used for trussing poultry. FIG. 1 shows a silicone band with a circular cross-section. However, the silicone band may have a square, rectangular, triangular or any other cross-sectional shape.
[0032] FIGS. 8 and 9 show the silicone bands 10 positioned on the food items 12 . The flexibility of the silicone bands will allow the silicone bands 10 to be stretched over the food item 12 and positioned on the food item. The silicone bands 10 will retract and compress the food item, thereby helping the food item to retain its shape. The silicone bands 10 retain flexibility at extremely high temperatures, and will expand and contract in concert with any expansion or contraction of food item 12 during the cooking process. Once the cooking is complete, the silicone bands 10 and accompanying food item 12 are removed from the heat source. The silicone bands 10 are released from the food item 12 . Typically, the silicone bands 10 are released by simply cutting the bands with a knife or scissors. The elasticity of the silicone bands will cause the silicone bands to contract and pull away from the food item after cutting the silicone bands. Food item 12 will not stick to the silicone bands 10 because the silicone bands are inert. After releasing, the silicone bands are easily removed from the food item 12 by simply pulling the silicone bands 10 from the food item 12 .
[0033] FIG. 9 shows the use of a larger diameter silicone band for trussing poultry. In this case, the inventor prefers to use a 5-7 inch diameter silicone band. The silicone band 10 is placed alongside the poultry carcass 12 , and toothpick 16 is used to pierce the two sides of poultry cavity. The silicone band 10 is positioned behind toothpick 16 and in front of the poultry. The silicone band 10 is then twisted and another toothpick 16 is used to pierce the two sides of the poultry cavity. The silicone band 10 again is positioned behind the toothpick 16 and in front of the poultry. The number of toothpicks used and the number of twists in the silicone band is dependent upon the size of the poultry and the diameter of the silicone band.
[0034] Another embodiment of the invention is shown in FIG. 2 , the silicone string 18 . The silicone string 18 may come in any length, and may be cut to any desired length depending on the cooking needs. For example, silicone string 18 may be used instead of the silicone bands 10 to truss poultry, or to tie roasts. The inventor currently prefers using solid silicone string, as shown in FIG. 2 . However, the silicone string may be hollow in the middle, as is typical of silicone tubing. The presence or absence of a hollow core will not affect the use of the device. Like the silicone bands, the silicone string may have any cross-sectional shape.
[0035] The silicone string 18 is positioned on a food item by stretching and wrapping the silicone string 18 around a food item and tying it in place. The silicone string 18 will expand and contract with the food item. After cooking is complete the silicone string and food item are removed from the heat source. The silicone string is released either by cutting or untying, and is easily removed from the food by pulling one end of the silicone string 18 .
[0036] The connected double-O 20 is a unitary silicone structure, as shown in FIG. 3 . The connected double-O 20 is designed for use on poultry hocks 26 . The connected double-O 20 is positioned around the ankle joints of poultry hocks prior to cooking, as shown in FIG. 3 . When cooking a chicken the inventor currently prefers using a connected double-O 20 in which each O 22 is ⅝″ diameter, and the connecting bar 24 is approximately ¼″ long. However, the size of the O 22 and the connecting bar 24 may be varied to accommodate larger poultry such as turkey, or smaller poultry such as game hens. After cooking is complete, the connected double-O 20 and food item 12 are removed from the heat source. The connected double-O 20 is released and removed from the poultry by cutting with a knife or scissors and pulling the connected double-O 20 from the poultry hock. Alternatively the connected double-O 20 may be released and removed by stretching and pulling the device from the poultry hock.
[0037] FIG. 4 shows the silicone mesh 28 . The silicone mesh 28 is an interlocking pattern of silicone forming essentially square or rectangular interstitial spaces 30 . The size and shape of the interstitial spaces 30 can be varied as needed for different cooking or food preparation techniques. Currently, the inventor prefers that the mesh have an interstitial space of ⅛ inch, and a thickness of approximately 1/32 inch. However, the size of the interstitial space and the mesh thickness can be varied, as needed. The mesh may come in sheets, or in roll form.
[0038] FIG. 5 shows the silicone perforated sheet 32 . The silicone perforated sheet 32 may come in any shape and thickness, and can be varied depending on the food preparation and cooking needs. The sheets 32 may be cut, as needed by the chef prior to use. Currently, the inventor prefers to use silicone perforated sheets that are approximately 1/32 inch thick, and approximately 20 inches square. This size is convenient to work with, and may be cut to the appropriate size. Alternatively, the sheets may come in a large roll, with a width of either 16 or 24 inches.
[0039] The silicone perforated sheets are covered with a plurality of holes 34 . The size of the holes may be varied, as needed. Currently, the inventor prefers to have approximately 200 of holes per inch, with each hole being the size of a pinprick. However, any number of holes per inch, and any diameter hole may be used to suit a variety of cooking needs
[0040] Either the silicone mesh or the silicone perforated sheets may be used whenever cheesecloth is used in cooking. For example, cheesecloth is frequently used to braise meat, poach fish, poach dessert fruits, or to prepare chicken galantine. In every situation, instead of using cheesecloth, the chef may use the silicone mesh or the silicone perforated sheet. For example, the mesh 28 may be used to poach a food item 12 . As shown in FIG. 10 the mesh is positioned so that it supports fish during poaching. Similarly, the perforated sheet 32 may be used to poach a food item 12 . As shown in FIG. 11 the silicone perforated sheet 32 is positioned to support a dessert pear during poaching.
[0041] The silicone mesh or perforated sheets may be positioned to hold and support the food item during cooking. The silicone mesh or perforated sheets are easily released and removed after cooking, without imparting and toxins, residue, or taste to the food item. The silicone perforated sheets or silicone mesh may be released and removed from the food item by cutting and pulling the silicone device from the food item, or by stretching and pulling the silicone device from the food item.
[0042] In another embodiment, as shown in FIG. 7 , the silicone mesh or perforated sheets are tube-shaped 36 , with a first end 38 and a second end 40 . The tube-shaped silicone device 36 may have a first end that is open, and a second end that is closed as shown in FIG. 7B . Alternatively, the tube-shaped silicone device 36 both the first end 38 second end 40 may be open, as shown in FIG. 7A . The tube-shaped device 36 provides rapid support for food items. For example, the tube-shaped device 36 may be positioned on a lamb shank by slipped the tube-shaped device 36 around a lamb shank prior to cooking. After cooking is complete, the silicone device is released and removed from the food item by cutting and pulling the silicone device from the food item, or by stretching and pulling the silicone device from the food item.
[0043] Instead of using polyethylene, polyvinylidene chloride, vinyl, or other similar wrap, a chef may use any of the silicone devices for food that is prepared and frozen for later use. Polyethylene, polyvinylidene chloride, vinyl, or other similar wrap is not designed for use at high temperatures, and breaks down during cooking. Any of the silicone devices, and particularly the silicone film 42 , may be used in place of polyethylene, polyvinylidene chloride, vinyl, or other similar wrap wrap.
[0044] Institutional chefs frequently prepare large quantities of food that is frozen prior to use. For example, an institutional chef may prepare several trays of lasagna. Typically, the trays are covered in polyethylene, polyvinylidene chloride, vinyl, or other similar wrap, then wrapped in aluminum foil and frozen. Chefs use polyethylene, polyvinylidene chloride, vinyl, or other similar wrap because the acid in the tomato sauce will interact with and dissolve aluminum foil if the tomato sauce is in direct contact with the aluminum foil. The lasagna trays are frequently removed from the freezer and placed in the oven without removing the polyethylene, polyvinylidene chloride, vinyl, or other similar wrap.
[0045] Polyethylene, polyvinylidene chloride, vinyl, and other similar wraps break down when exposed to heat and may impart toxins to the lasagna. Rather than use these wraps, a chef may position the silicone film 42 by stretching or laying the silicone film 42 over the food item 12 that is to be frozen, as shown in FIG. 12 , and then freezing the food item along with the silicon film. Aluminum foil 44 may be placed on top, if needed. The silicone film 42 is inert during cooking and can go from freezer to oven without breaking down. After cooking is complete, the food item and silicon film are removed from the oven. The silicone film 42 is released from the food item 12 by cutting with knife or scissors and pulling the silicone film 42 from the food item 12 , or by lifting and pulling the silicone film 42 from the food item 12 .
[0046] The silicone devices may also be used in food preparation, even when the food is not exposed to heat. For example, jams, jellies, yogurt and other items are frequently strained during preparation. The silicone mesh or perforated sheets may be used to strain food by positioning the silicone mesh or perforated sheet so that the food item strains through the silicone device. Similarly, a caterer may use the silicone bands to pre-portion food prior to serving by positioning the silicone devices on food items prior to the catered event. At the catered event, the caterer may release the silicone devices from the food items by cutting and removing the silicone devices. Each food item is then placed on a separate plate.
[0047] The silicone devices may optionally be colored so that the chef may quickly find and release the silicone devices. The silicone devices may optionally be sterilized and reused, or may be discarded after one use.
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The invention involves silicone devices and a method for using the silicone devices for food preparation and for cooking. The silicone devices come in a variety of shapes: bands, string, mesh, perforated sheets, connected double-Os, and film. The silicon devices may be used when food is prepared, then frozen and later cooked; to support food during cooking; or in food preparation when the food is not heated. The silicon devices may be stretched and placed over a food item prior to cooking and will support the food item during cooking. The silicone devices retain their elasticity when exposed to heat and continue to hold the food in shape while cooking. After cooking is complete, the silicone devices are quickly and easily removed from the food without sticking to the food.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of PCT Application No. PCT/JP2008/072456, filed Dec. 10, 2008, which was published under PCT Article 21 (2) in Japanese.
[0002] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2007-319000, filed Dec. 10, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates to a luminescence measurement method and a luminescence measurement system for observing biological samples (for example, samples including cells). In particular, this invention relates to a method and a luminescence measurement system for performing the quantitative measurement of substances that may exist excessively in a biological sample.
[0005] 2. Description of the Related Art
[0006] Conventionally, luciferase which is a luminescence enzyme or GFP which is a fluorescence enzyme has been employed in a biological function analysis. In particular, an assay utilizing the luminescence from a luciferin-luciferase reaction, etc. is widely employed as an experimental technique since the assay is advantageous, as compared with the method of employing fluorescence, in many respects such as (1) excellent S/N ratio; (2) excellent quantitative performance; (3) non-cytotoxicity in the employment of exciting light; etc.
[0007] For example, the luciferase assay is employed for quantitatively measure the quantity of ATP in a biological sample by measuring the intensity of luminescence which is steadily generated by luciferase or employed for observing the level of manifestation of a specified gene through the determination of luminescence intensity that can be performed by introducing luciferase gene, together with a reporter sequence, into cells.
[0008] On this occasion, as one example of the modification of the luciferase assay, there is employed a genetic engineering method of modifying the luciferase, i.e. luminescence enzyme itself, thereby providing the luciferase with heat resistance or high luminescence properties (see Bruce R. Branchini et al. Biochemistry, 2003, 42, pp. 10429-1046).
BRIEF SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0009] However, the conventional measuring method using a luminescence enzyme is accompanied with a problem that if a substance to be used as a substrate is existed more than a prescribed level in a biological sample, it becomes difficult to detect differences or fluctuation of luminescence intensity that will be caused in proportion to the quantity of the substrate, thereby making it difficult to quantitatively measure an object to be measured.
[0010] Especially, when it is desired to quantitatively measure ATP in an assay system utilizing a luciferin-luciferase reaction, the quantity of ATP is required to vary according to reaction rate-limiting. However, as the quantity of ATP becomes close to a state of saturation relative to luciferase, it becomes difficult to obtain an ATP-dependent luminescence intensity.
[0011] Further, when the substance to be used as a substrate is existed excessively relative to a luminescence enzyme, a difference in luminescence intensity relative to the luminescence intensity to be brought about by the manifestation of gene is caused to generate extremely, thereby bringing about a problem that it becomes difficult to concurrently detect the quantity of the substance (for example, within the same exposure time) by making use of the same device which is designed to detect a very weak beam.
[0012] The present invention has been accomplished in view of the aforementioned circumstances and, therefore, objects of the present invention are to provide a luminescence measurement method and a luminescence measurement system, which are capable of obtaining luminescence intensity in proportion to the quantity of an object substance even in a case where the object substance is existed more than a prescribed level in an biological sample, thereby making it possible to quantitatively measure the quantity of the object substance. Further objects of the present invention are to provide a luminescence measurement method and a luminescence measurement system, which are capable of overcoming the aforementioned problem of the generation of extreme difference in luminescence intensity, thereby making it possible to concurrently detect the quantity of an object substance existing more than a prescribed level in an biological sample by making use of the same device which is designed to detect a very weak beam.
Means for Solving the Problems
[0013] As a result of extensive studies performed by the present inventor, it has been found out that it is possible to more accurately measure the quantity of an object substance by selectively employing a luminescence-associated material which is low in affinity to the object substance provided that the object substance such as ATP is existed more than a prescribed level in a biological sample (for example, in cells). Especially, it has been found possible to obtain an object-depending luminescence intensity by suitably selecting a luminescence-associated material which is high in a Km value so as to prevent the concentration of the substance from approaching to the vicinity of Vmax in the Michaelis-Menten equation on the occasion of quantitatively measuring an object substance such as ATP. Further, with regard to the sequence of gene, it has been found out that Genji firefly (scientific name: Luciola cruciata; the name of luciferase thereof is referred to as Genji in this specification) among several kinds of firefly belonging to Luciola which are known to exist in the territory of Japan exhibits a difference in Km value as described in the experiments conducted as an embodiment of the present invention. The employment of luciferase as a luminescence marker in conformity with the intended purpose by taking advantage of this difference in Km value is one of the important subject matters of the present invention.
[0014] Namely, to solve the problems mentioned above and achieve the objectives, the luminescence measuring method for measuring luminescence emitted from a biological sample according to the present invention is characterized by comprising the step of preparing a biological sample containing a luminescence-associated protein which is capable of reacting with a substance existing more than a prescribed quantity in the biological sample, the protein having a Km value which is higher than a prescribed value which enables to quantitatively measure a luminescence intensity in dependence with the substance, the step of measuring the luminescence intensity emitted from the biological sample prepared in above-described preparing step and the step of outputting a measured result obtained from each of regions and/or sites of the biological sample, that is, a measured result in regard to the luminescence intensity obtained in above-described measuring step.
[0015] Further, the luminescence measuring method according to the present invention is characterized by the substance being ATP, the luminescence-associated protein being luciferase, and the Km value being not less than 364.
[0016] Further, the luminescence measuring method according to the present invention is characterized by the luciferase being Yaeyama Hime firefly-originated luciferase to be created based on the DNA sequence of Sequence No. 1.
[0017] Further, the luminescence measuring method according to the present invention is characterized by the step of measurement including a step of picking up a luminescence image based on the biological luminescence of the biological sample including a plurality of cells.
[0018] Further, the luminescence measuring method according to the present invention is characterized by the step of measurement including a step of measuring the luminescence intensity of each of the cells.
[0019] Further, the luminescence measuring method according to the present invention is characterized by the step of preparation comprising a step of preparing the biological sample by making use of a plurality of luminescence-associated proteins differing in the Km value from each other.
[0020] Further, the luminescence measuring method according to the present invention is characterized by the step of measurement being performed depending on the Km value.
[0021] Further, the luminescence measuring method according to the present invention is characterized by the step of output being performed depending on the Km value.
[0022] Moreover, the present invention is a luminescence measurement system for executing the luminescence measuring methods mentioned above, the system is characterized by comprising a picking up section for obtaining luminescent image from a biological sample, an image analysis section for executing image processing for analyzing the luminescent image obtained from the picking up section, an output device for outputting a result of the analysis of image obtained from the image analysis section, and a dynamic range adjusting section for executing the picking up section and the image analysis section in conformity with the Km value of luminescent protein used in the biological sample.
[0023] Further, in the luminescence measurement system according to the present invention, it is characteristic that the dynamic range adjusting section is provided with a plurality of control modes.
[0024] Moreover, in the luminescence measurement system according to the present invention, it is characteristic that the system further comprises an input device for designating a desired region and/or a desired site in the biological sample, and a memory section for storing information input from the input device, wherein the dynamic range adjusting section is designed to output an output content in which an image and an analyzed image are formulated in conformity with the information stored in the memory section (in correspondence with the dynamic range, the picking up section and the image analysis section execute the processing based on information stored in a memory section, and an output apparatus outputs the results of imaging corresponding to the information to be output).
EFFECTS TO BE OBTAINED FROM THE INVENTION
[0025] According to the method of the present invention, a biological sample containing a luminescence-associated protein is prepared. In this case, the protein which is capable of reacting with a substance existing more than a prescribed level in the biological sample and which has a higher Km value than a predetermined level is selected, thereby making it possible to quantitatively measure luminescence intensity in proportion to the quantity of the substance. Then, the luminescence intensity to be generated from the biological sample thus prepared is measured, thus making it possible to output measured results of each of region and/or site of the biological sample. By doing so, it is possible to perform quantitative measurement in proportion to the quantity of the substance even in a case where the substance to be measured is existed more than a prescribed level in the biological sample. Further, since it is possible to adjust the luminescence intensity so as to prevent the generation of an extreme difference in luminescence intensity, it is possible to realize the merit that the examination of many items can be concurrently performing by making use of the same very weak beam detecting apparatus. Furthermore, it is also possible to realize the merit that a plurality of regions of a biological sample or a plurality of sites in the same cell can be concurrently measured and hence it is now possible to perform the analysis of each of regions (or each of sites) which are related to a luminescence picture image that has been obtained.
[0026] According to the present invention, since the substance to be measured may be ATP and the luminescence-associated protein may be luciferase and the Km value is not less than 364 μM, it is possible to realize the merit that ATP can be rate-determined, thus making it possible to obtain a quantitative luminescence intensity depending on the existence of ATP.
[0027] According to the present invention, since the luciferase originated from Yaeyama-hime firefly that can be created based on the DNA sequence of Sequence No. 1 is employed, it is possible to realize the merit that a large ATP-dependent difference in luminescence intensity and hence a glow type luminescence pattern. Especially, as the concentration of ATP within cells is decreased by a chemical treatment from 1.35 mM to 0.65 mM, the reaction velocity is expected to decrease from about 80% of Vmax to about 60% according to Michaelis-Menten equation when luciferase (Yaeyama) originated from Yaeyama-hime firefly is employed, thereby generating a difference of 20% in the reaction velocity thus further facilitating the detection of Yaeyama as compared with the case where GL3 is employed (a difference of about 5% in reaction velocity).
[0028] According to the present invention, in the step of measuring the luminescence intensity, a luminescence picture image of biological sample containing a plurality of cells is pictured based on bioluminescence. By doing so, it is possible to obtain the merit that the regions of a plurality of cells and/or a plurality of sites within the same cell can be concurrently measured.
[0029] According to the present invention, in the step of measuring the luminescence intensity, it is performed for each one of cells. By doing so, it is possible to obtain the merit that it is possible to designate the region and/or site to be measured for each cell and to quantitatively measure a plurality of regions and sites at the same time.
[0030] According to the present invention, in the step of preparing a biological sample, the biological sample is prepared by making use of a plurality of luminescence-associated proteins differing in Km value from each other. By doing so, it is possible to obtain the merit that it is possible to perform quantitative measurement concurrently even when there is a large difference in the quantity of object substance to be measured.
[0031] According to the present invention, in the step of measuring the luminescence intensity, the measurement is performed in correspondence with the Km value. By doing so, it is possible to obtain the merit that it is possible to perform quantitative measurement by changing the intervals of image pick-up or exposure time in correspondence with the Km value of the luminescence-associated proteins. For example, the kinetic analysis as to how the dynamics of a bioactive substance which is wide in dynamic range has been changed and also the analysis of the expression/fluctuation of a specific gene as to how the transcription of the specific gene related to the dynamics of the bioactive substance has been controlled can be performed quickly or at real-time on the same cell (or cell group).
[0032] According to the present invention, in the step of outputting the results of analysis, the out is executed in correspondence with the Km value. By doing so, it is possible to obtain the merit that the results of analysis can be output after they have been subjected to conversion processing based on various parameters (coloration, contrast, dimension, display speed of moving images, etc.) in conformity with the dynamic range based on the Km value.
[0033] According to the present invention, a luminescent picture image to be derived from a biological sample is obtained in correspondence with the Km value of luminescent protein used in the biological sample and the image processing for analyzing the luminescent picture image is performed in correspondence with the Km value of luminescent protein used in the biological sample before outputting the results of the image analysis. By doing so, it is possible to obtain the merit that a plural kinds of measurement differing in dynamic range from each other in correspondence with Km value can be carried out to the same or different objects to be analyzed.
[0034] According to the present invention, the adjustment of dynamic range having a plurality of control modes is performed. By doing so, not only a measuring item having a wide dynamic range such as ATP but also a measuring item having a relatively narrow dynamic range such as the expression of a specific gene, for example, can be carried out to the same object to be analyzed, thereby making it possible to track concurrently or at real-time each of regions and/or sites on the same picture image.
[0035] According to the present invention, a desired region and/or site in a biological sample is designated through an input apparatus, and information that has been input by the input apparatus is stored in a memory section, after which, based on the information stored in the memory section, the image pick-up section and the image analysis section are actuated by means of the dynamic range adjustment section, thereby enabling the results of imaging corresponding to the information to be output by means of an output apparatus. By doing so, it is possible to obtain the merit that the dynamic range can be adjusted in conformity with the Km value of luminescence-associated proteins so as to carry out the image pick-up processing, analytical processing and output processing in correspondence with the dynamic range, thereby enabling a plural kinds of measurement differing in dynamic range from each other in correspondence with Km value to be carried out to the same or different objects to be analyzed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0036] FIG. 1 is a diagram illustrating one example of the overall construction of a luminescence observation system 100 ;
[0037] FIG. 2 is a diagram illustrating one example of the construction of a luminescent image pick-up unit 106 of the observation system 100 ;
[0038] FIG. 3 is a diagram illustrating another example of the construction of a luminescent image pick-up unit 106 of the observation system 100 ;
[0039] FIG. 4 is a block diagram illustrating one example of the construction of an image analyzer 110 of the observation system 100 ;
[0040] FIG. 5 is a table showing the Km value of D-luciferase and the Km value of various kinds of luciferase to ATP;
[0041] FIG. 6 is a graph showing the ultraviolet/visible light absorption spectrum of D-luciferase;
[0042] FIG. 7 is a graph showing the ultraviolet/visible light absorption spectrum of ATP;
[0043] FIG. 8 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of CBG;
[0044] FIG. 9 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of CBG;
[0045] FIG. 10 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of CBG;
[0046] FIG. 11 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of CBR;
[0047] FIG. 12 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of CBR;
[0048] FIG. 13 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of CBR;
[0049] FIG. 14 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of ELuc;
[0050] FIG. 15 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of ELuc;
[0051] FIG. 16 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of ELuc;
[0052] FIG. 17 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of Genji;
[0053] FIG. 18 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of Genji;
[0054] FIG. 19 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of Genji;
[0055] FIG. 20 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of GL3;
[0056] FIG. 21 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of GL3;
[0057] FIG. 22 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of GL3;
[0058] FIG. 23 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of D-luciferase of Yaeyama;
[0059] FIG. 24 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of D-luciferase of Yaeyama;
[0060] FIG. 25 is a graph showing Hanes-Woolf plots obtained relative to the concentration of D-luciferase of Yaeyama;
[0061] FIG. 26 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of ATP of CBG;
[0062] FIG. 27 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of CBG;
[0063] FIG. 28 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of CBG;
[0064] FIG. 29 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of ATP of CBR;
[0065] FIG. 30 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of CBR;
[0066] FIG. 31 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of CBR;
[0067] FIG. 32 is a graph showing fluctuation of luminescence intensity due to an increase in concentration of ATP of ELuc;
[0068] FIG. 33 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of ELuc;
[0069] FIG. 34 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of ELuc;
[0070] FIG. 35 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of ATP of Genji;
[0071] FIG. 36 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of Genji;
[0072] FIG. 37 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of Genji;
[0073] FIG. 38 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of ATP of GL3;
[0074] FIG. 39 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of GL3;
[0075] FIG. 40 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of GL3;
[0076] FIG. 41 is a graph showing the fluctuation of luminescence intensity due to an increase in concentration of ATP of Yaeyama;
[0077] FIG. 42 is a graph showing Lineweaver-Burk plots obtained relative to the concentration of ATP of Yaeyama;
[0078] FIG. 43 is a graph showing Hanes-Woolf plots obtained relative to the concentration of ATP of Yaeyama;
[0079] FIG. 44 is a table illustrating the summary of the results wherein the Km values are calculated from the Lineweaver-Burk plots and the Hanes-Woolf plots created on the basis of the photon count values obtained by means of a luminometer;
[0080] FIG. 45 is a graph showing the fluctuation of luminescence of ELuc obtained on the basis of the quantity of ATP in cells measured using a luminometer (Chronos);
[0081] FIG. 46 is a graph showing the fluctuation of luminescence of GL3 obtained on the basis of the quantity of ATP in cells measured using a luminometer (Chronos);
[0082] FIG. 47 is a photograph showing a picture of luminescence image taken immediately after the stimulation using chemicals in an ELuc-expressing HeLa cell;
[0083] FIG. 48 is a graph showing the fluctuation of luminescence intensity after the STS stimulation in each of cells (ELuc expressing HeLa cells: 1 - 7 ) that has been analyzed from the images ( 1 - 7 ) each rectangularly encircled in FIG. 47 ;
[0084] FIG. 49 is a photograph showing one example of the luminescent image photographed prior to the stimulation (before the Apoptosis induction by way of the stimulation of cell), which was performed according to the process and conditions of experiment performed in Example 4;
[0085] FIG. 50 is a photograph showing an image obtained as three measurement regions (ROI: region of interest) were designated in the luminescent image shown in FIG. 49 ; and
[0086] FIG. 51 is a graph showing the brightness of luminescence in three measurement regions and a table thereof.
[0087]
[0000]
Explanation of symbols
100
Luminescence observation system
103
Vessel (Petri dish)
104
Stage
106
Luminescence image pick-up unit
106a
Objective lens (for observing luminescence)
106b
Dichroic mirror
106c
CCD camera
106d
Split image unit
106e
Filter wheel
106f
Imaging lens
108
Dynamic range adjusting section
110
Image analyzer
112
Control section
112a
Luminescent image pick-up instruction
section
112b
Luminescent image acquisition section
112c
Image analysis section
112d
Analysis result output section
114
Clock-generating section
116
Memory section
118
Communication interface section
120
Input/Output interface section
122
Input apparatus
124
Output apparatus
DETAILED DESCRIPTION OF THE INVENTION
[0088] Next, various embodiments of the luminescence measurement method and the luminescence measurement system according to the present invention will be explained in detail with reference to drawings. Incidentally, these embodiments are not intended to limit the scope of the present invention.
[0089] Especially, in the following embodiments, there may be explained cases where the present invention is applied to luminescent imaging. However, the present invention is not limited to such a luminescent imaging, but can be applied likewise to the measuring method using a luminometer, for instance.
[0090] First of all, the construction of a luminescence observation system (luminescence measuring system) 100 to be employed in the luminescence measurement method (specifically, a measuring step and an output step) according to the present invention will be explained with reference to FIG. 1 , FIG. 2 and FIG. 3 . FIG. 1 shows a diagram illustrating one example of the overall construction of luminescence observation system 100 .
[0091] As shown in FIG. 1 , the luminescence observation system 100 is constituted by a vessel 103 (specifically, it may be a Petri dish, a slide glass, a microplate, a gel-supporting member, a fine particle carrier, etc.) housing a biological sample 102 , a stage 104 for mounting the vessel 103 , a luminescence image pick-up unit 106 , and an image analyzer 110 . Herein, the luminescence observation system 100 may be constructed such that the luminescence image pick-up unit 106 for measuring a weak luminescence is disposed on the underside of the stage 104 so as to completely intercept the disturbing light from the direction above the sample on the occasion of opening or closing the cover, thereby making it possible to increase the S/N ratio of luminescent image. The luminescence image pick-up unit 106 may be formed of a laser scanning type optical system.
[0092] The biological sample 102 is formed of a living cell containing luminescence-associated protein that can be obtained by introducing a luminescence-associated gene into the protein. This biological sample 102 contains more than a prescribed quantity of a substance which is capable of reacting with the luminescence-associated protein. As for the luminescence-associated protein, it is selected from those exhibiting more than a prescribed level of Km value so as to make it possible to quantitatively determine the luminescence intensity in correspondence with the quantity of the substance. As for the object to be analyzed in this case, it may be a biological tissue including cells, or various kinds of internal organs or organ including such a biological tissue. Alternatively, the object to be analyzed may be an embryo or a bion having such a biological tissue, internal organ or organ. The stage 104 for sustaining the object to be analyzed may be designed in such a manner that specific cell(s) (one or more) to be analyzed would not be moved out of the visual field (preferably, the optical axis) for observing the luminescence of the object during a desired time period of analysis (for example, an object-fixing tool or a tracking mechanism for the stage).
[0093] The luminescence image pick-up unit 106 is, specifically, formed of an upright type luminescence microscope which is capable of picking up the luminescent image of the biological sample 102 . As shown in FIG. 1 , the luminescence image pick-up unit 106 is constituted by an objective lens 106 a , a dichroic mirror 106 b , a CCD camera 106 c and an imaging lens 106 f . The objective lens 106 a is, specifically, constructed to have a value of (the number of apertures/magnification) 2 which is confined to 0.01 or more. The dichroic mirror 106 b is employed for separating, color by color, the luminescence emitted from the biological sample 102 , thereby measuring, color by color, the quantity of luminescence and the luminescence intensity by making use of the luminescence of two colors. The CCD camera 106 c is used for taking the luminescent image and the brightfield image of the biological sample 102 that have been projected, through the objective lens 106 a , the dichroic mirror 106 b and the imaging lens 106 f , on the chip surface of the CCD camera 106 c . Further, the CCD camera 106 c is connected with an image analyzer 110 to thereby enable it to communicate, through a wire or wireless circuit, with the image analyzer 110 . In this case, if a plurality of biological samples 102 are existed within the range of picking up, the CCD camera 106 c may be designed so as to perform the image pick-up of luminescence images and brightfield images of the plurality of biological samples 102 . The imaging lens 106 f is employed for picking up the image (specifically, an image including the biological sample 102 ) that has been entered, through the objective lens 106 a and the dichroic mirror 106 b , into the imaging lens 106 f . Incidentally, in FIG. 1 , there is illustrated one example wherein luminescent images each corresponding to a couple of beams separated by the dichroic mirror 106 b are individually taken up by a couple of CCD cameras 106 c . Therefore, in a case where only one beam is employed, the luminescence image pick-up unit 106 may be constituted by the objective lens 106 a , a single CCD camera 106 c and the imaging lens 106 f.
[0094] When it is desired to measure the quantity of luminescence and the intensity of luminescence color by color by making use of two color beams, the luminescence image pick-up unit 106 may be constituted by the objective lens 106 a , the CCD camera 106 c , the split image unit 106 d and the imaging lens 106 f as shown in FIG. 2 . Further, the CCD camera 106 c may be used for taking the luminescent image (split image) and the brightfield image of the biological sample 102 that have been projected, through the split image unit 106 d and the imaging lens 106 f , on the chip surface of the CCD camera 106 c . The split image unit 106 d is used for separating beam emitted from the sample 102 color by color and for measuring the quantity of luminescence and the intensity of luminescence color by color by making use of two color beams.
[0095] Further, when it is desired to measure the quantity of luminescence and the intensity of luminescence color by color by making use of a plurality of color beams (namely, when a multi-color beam is employed), the luminescence image pick-up unit 106 may be constituted by the objective lens 106 a , the CCD camera 106 c , a filter wheel 106 e and the imaging lens 106 f as shown in FIG. 3 . In this case, the CCD camera 106 c may be used for taking the luminescent image and the brightfield image of the biological sample 102 that have been projected, through the filter wheel 106 e and the imaging lens 106 f , on the chip surface of the CCD camera 106 c . The filter wheel 106 e is used for separating beam emitted from the sample 102 color by color by way of filter exchange and for measuring the quantity of luminescence and the intensity of luminescence color by color by making use of a plurality of color beams.
[0096] Now turn back to FIG. 1 , the image analyzer 110 is, specifically, formed of a personal computer. This image analyzer 110 is roughly constituted as shown in FIG. 4 by a control section 112 , a clock-generating section 114 for measuring the time of the system, a memory section 116 , a communication interface section 118 , an input/output interface section 120 , an input apparatus 122 and an output apparatus 124 , wherein all of these sections are connected with each other through a bus. The details of these constructions shown in FIGS. 1 to 4 can be understood by referring to International Patent Publication WO2006/106882 (the title thereof: A method of measuring a quantity of luminescence at a prescribed site, An apparatus of measuring a quantity of luminescence at a prescribed site, A method of measuring a quantity of manifestation, and A measuring apparatus). Since this International Patent Publication discloses a method of analyzing two kinds of medical information on the same cell by making use of both of the fluorescent image and luminescent image thereof, the method can be also applied, as another embodiment of the present invention, to the method of analysis wherein a plural kinds of fluorescent marker substance differing in dynamic range (fluorescence-associated protein such as GFP, CFP, YFP, RFP, etc., for example) are employed. Further, in the case of BRET (bioluminescence resonance energy transfer), since it is an optical phenomenon wherein bioluminescence is combined with fluorescence, it is possible to obtain the advantage that a system for exciting fluorescence can be dispensed with. Furthermore, it is also possible to utilize, as fluorescence-associated protein, Oberlin, etc. other than luciferase.
[0097] The memory section 116 is formed of storage means, so that it may be, as a specific example, a memory device such as RAM, ROM, etc., a stationary disk device such as hard disk, a flexible disk, an optical disk, etc. This memory section 116 is designed to store data obtained by the processing of each of the sections of the control section 112 . The communication interface section 118 acts to mediate the communication between the image analyzer 110 and the CCD camera 106 a . Namely, the communication interface section 118 is provided with a function to communicate with other terminals so as to receive or send data through a wire or wireless communicating circuit. The input/output interface section 120 is connected with an input apparatus 122 and with an output apparatus 124 . As for the output apparatus 124 in this case, it is possible to employ not only a monitor (including a home television) but also a speaker or a printer (incidentally, in the following description, the output apparatus 124 may be referred to as a monitor). Further, as for the input apparatus 122 , it is possible to employ a key board, a mouse, a microphone as well as a monitor which is capable of functioning as a pointing device in cooperation with a mouse. In this case, based on a luminescent image displayed in a monitor employed as the output apparatus 124 , an interested region including one or more of specific cells (or a cell group) to be analyzed within a desired time period of analysis or an interested site in a cell as well as measuring item(s) are designated through the input apparatus 122 by a user, thereby enabling the positional information (adress) of the region (or site) designated in the observing visual field to be stored in the memory section 116 . Due to the information thus stored in this manner, it is now possible to perform image analysis which makes it possible to check up a plurality of regions (or sites) or temporally check up the specific cells (or a cell group) on the basis of time series.
[0098] Further, the image analyzer 110 is constructed in such a manner that when the kind (or the Km value itself) of luminescence-associated protein used as an object to be placed on the stage 104 is input through the input apparatus 122 by a user, the dynamic range of each of measuring item related to one of more of luminescence-associated protein to be used is specifically selected by a dynamic range adjusting section 108 from memory information that has been stored in advance such as a look-up table, thereby enabling a control mode corresponding to the collated dynamic range to be instructed to the control section 112 . In this case, once the kind of luminescence-associated protein is specified, the kind of ground substance which causes the luminescence-associated protein to radiate can be univocally determined, so that the Km value to the ground substance may be also stored in advance in the look-up table. The control section 112 is designed such that each of processes (an imaging process, an image-obtaining process, a picture image processing for analysis and a process of analyzed results) according to the instructed control mode can be executed at each of the sections (a luminescent image pick-up instruction section 112 a , a luminescent image acquisition section 112 b , an image analysis section 112 c and an analysis result output section 112 d ) while coordinating with the address of each of the designated regions (or sites) that have been stored in the memory section 118 . Furthermore, the information related to the luminescent image and/or the analyzed results thus obtained is displayed on the picture plane of the output apparatus 124 after the information has been converted, through the dynamic range adjusting section 108 , to an output format corresponding to the dynamic range. Incidentally, when it is desired to combine the information with a measuring item wherein luminescence-associated protein is employed, it is preferable to input the kind (or Km value itself) of the luminescence-associated protein. In this case however, since it is conceivable that, due to the modification of the luminescence-associated protein or fluorescence-associated protein, the Km value thereof may be varied from the Km value before the modification thereof, it is preferable to input the Km value of the protein to be actually used.
[0099] As for the instruction of picking up corresponding to the dynamic range and to be executed by the luminescent image pick-up instruction section 112 a , it includes picking up intervals (for example, a video mode of not more than 5 seconds, a video mode consisting of intermediate intervals ranging from 6 seconds to 10 minutes, a time lapse mode consisting of long picking up intervals ranging from 11 minutes to 120 minutes, or a combination of these modes). As for the instruction of acquisition corresponding to the dynamic range and to be executed by the luminescent image acquisition section 112 b , it includes for example the exposure time (a short time exposure mode of not more than one second, an intermediate exposure time exposure mode ranging from 2 seconds to 10 minutes and a long time exposure mode ranging from 6 minutes to 120 minutes) of an image pick-up device (for example, a CCD camera, a CMOS camera, etc.). At the image analysis section 112 c , the analysis of each of the regions (or sites) related to the obtained luminescent image is executed based on such a computing algorithm that makes it possible to analyze each kind of measuring items in correspondence with the dynamic range. At the analysis result output section 112 d also, the output of the output format (an image format, a numerical format, a graphic format, etc.) corresponding to each kinds of measuring items is executed. Finally, at the dynamic range adjusting section 108 , the result of each kind of analyzed results that has been transmitted from the analysis result output section 112 d is subjected to a conversion processing wherein the same or different output contents (image, numeral, graph, etc.) are converted based on a parameter (selected from the group consisting of color, color tone, gradation, brightness, dimension and video display speed) corresponding to the dynamic range before the result is displayed at the output apparatus 124 . According to this system, a plural kinds of objects to be measured and varying in dynamic range or in Km value with respect to a substance to be measured and corresponding to measuring item can be applied to the same or different object to be analyzed. For example, a measuring item having a wide dynamic range such as ATP and a measuring item having a relatively narrow dynamic range such as a specific kind of gene expression may be applied to the same object to be analyzed, thereby realizing the advantage that each of the regions and/or site on the same picture image can be tracked concurrently and at real time. Although it is made possible to identify cells one by one as a luminescent image by superimposing the luminescent image with a bright visual field image which has been also obtained in this example, the luminescent image may not be superimposed with the bright visual field image, provided that the image pick-up device or luminescent reagent (luciferase, luciferin or other kinds of additives) is high in sensitivity. Further, as described hereinafter, depending on a purpose, even if various kinds of luminescent protein such as a glow type or flash type luminescent protein are prepared to thereby enable the same biological sample to be simultaneously labeled, it is possible to carry out the picking up and the analysis by means of the aforementioned system. Therefore, it is possible to realize a combination of assays or a multi-assay.
[0100] The control section 112 is provided with a control program such as OS (Operating System), a program regulating various kinds of procedures and an internal memory for storing data required, thereby making it possible to execute various kinds of processes based on these programs. This control section 112 is roughly constituted by the luminescent image pick-up instruction section 112 a , the luminescent image acquisition section 112 b , the image analysis section 112 c and the analysis result output section 112 d.
[0101] The luminescent image pick-up instruction section 112 a is designed to instruct, through the communication interface section 118 , the CCD camera 106 c to execute the picking up of luminescent image and bright visual field image. The luminescent image acquisition section 112 b is designed to receive, through the communication interface section 118 , the luminescent image and the bright visual field image that have been taken by means of the CCD camera 106 c . The control section 112 is designed to control the luminescent image pick-up instruction section 112 a so as to execute repeated picking up of the luminescent image and the bright visual field image of biological sample 102 .
[0102] In this case, on the occasion of performing the picking up of the luminescent image of biological sample 102 by means of the CCD camera 106 c , a luminescence-associated protein having an appropriate Km value so as to prevent the generation of an extreme difference in luminescence intensity among the luminescence-associated proteins (for example, in a case where one of them is luciferase for quantitatively measure ATP and the other is luciferase for analyzing the gene expression) is selected (for example, luciferase having a higher Km value (Km>364 μM) as compared with the luciferase for analyzing the gene expression is selected as the luciferase for quantitatively measure ATP), thereby making it possible to concurrently perform the picking up in the same exposure time.
[0103] The image analysis section 112 c is designed to quantitatively measure the luminescence intensity of each of luminescent colors on the basis of the luminescent image that has been obtained at the luminescent image acquisition section 112 b . Further, the image analysis section 112 c is designed to quantitatively measure fluctuation with time of the luminescence intensity of each of luminescent colors on the basis of a plurality of luminescent images that have been obtained at the luminescent image acquisition section 112 b . The analysis result output section 112 d is designed to feed the result of analysis obtained at the image analysis section 112 c to the output apparatus 124 . In this case, the analysis result output section 112 d may be designed such that the time series data related to the luminescence intensity of each of luminescent colors that have been obtained at the image analysis section 112 c are turned into a graph, which is then displayed at the output apparatus 124 .
[0104] The above description illustrates one example of the construction of the luminescence observing system (luminescence measuring system) to be employed in the luminescence measuring method of the present invention. Incidentally, the output apparatus 124 may be designed such that a plurality of luminescent images corresponding to at least a portion of the time series numerical data can be fed in the form of video or parallel display to a monitor. As described above, according to the present invention, not only the kinetic analysis as to how the dynamics of a bioactive substance which is wide in dynamic range has been changed but also the analysis of the expression/fluctuation of a specific gene as to how the transcription of the specific gene related to the dynamics of the bioactive substance has been controlled can be performed quickly or at real-time on the same cell (or cell group). Therefore, it is possible to provide information accurately and quickly for use in the medical research or for clinical use (for example, response tests of drugs for the purpose of treatment, diagnosis and preventive medicine). Incidentally, in the case where a fluorescence image-taking unit is co-used in the analysis system for executing the method of the present invention, the fluorescence image-taking unit and the luminescent image pick-up unit may be placed on the same stage in such a manner that they are respectively disposed on a different optical axis or these units may be respectively constituted by a different apparatus (for example, a fluorescence microscope and a luminescence microscope) which is disposed on a different stage. Alternatively, these units may be designed to perform the picking up and the analysis while allowing a plurality of analyzing objects to successively move on the same or different stage. As for the analysis system, it can be applied also to a different kind of picking up system (various kinds of fiber scope (for example, an endoscope) and an image analysis type spectrometer (for example, a luminometer)) other than the aforementioned microscope-based system as long as the analysis system is equipped at least with the image analyzer as shown in FIG. 4 . Further, in the case where the object is formed of a biological sample which has been isolated from a living body and incubated or artificially processed (cells, living tissue, internal organs (or organs), etc.), the analysis system should preferably be constructed in combination with a suitable culture apparatus so as to maintain the biological activity of the object during a prescribed period of analysis. However, when the object is an individual, the picking up can be intermittently performed while appropriately supplying or feeding oxygen and nutrition to the individual in place of the culture apparatus, thereby making it possible to execute the analysis in the same manner as described above.
Example 1
Enzymological Properties of Various Kinds of Luciferase and Application of Luciferase to Luminescence Measurement
[0105] In this example 1, with a view to find out appropriate luciferase having a suitable Km value for the application of the present invention, the enzymological properties (Km value relative to D-luciferin and ATP) of luciferase available in the market (CBG, CBR, Eluc, Genji, GL3) were determined.
Experiment Method 1
Calculation of Km Value of Various kind of Luciferase Relative to D-Luciferin
[0106] D-luciferin was added to a 0.1M ATP solution (Tris-HCl (pH=8.0)) to obtain various kinds of solutions differing in ultimate concentration of D-luciferin from each other, i.e. 5 μM, 10 μM, 20 μM, 40 μM, 80 μM, 160 μM, 320 μM, 640 μM, respectively, thus preparing 8 kinds of solutions. Then, a 100 μg/ml luciferase solution was prepared by making use of 0.1M Tris-HCl (pH=8.0).
[0107] Then, D-luciferin solutions having the aforementioned concentrations were respectively aliquoted to a vessel having 96 wells, thus creating wells each containing 50 μl of D-luciferin solution. Then, the luciferase solution was connected with a standard pump of luminometer, after which a program was prepared so as to initiate the measurement concurrent with the addition of 50 μl of the luciferase solution to each of the wells.
[0108] Subsequently, the program was started to measure the photon-count value at each D-luciferin concentration. Based on the results obtained, Lineweaver-Burk plot and Hanes-Woolf plot were prepared to determine the Km value of each of luciferase relative to D-luciferin. In this case, the Lineweaver-Burk plot can be represented by the following formula (1) and the Hanes-Woolf plot can be represented by the following formula (2).
[0000]
Formula
(
1
)
1
v
=
Km
v
max
×
1
[
S
]
+
1
v
max
Formula
(
1
)
Formula
(
2
)
[
S
]
v
=
Km
v
max
+
[
S
]
v
max
Formula
(
2
)
Experiment Method 2
Calculation of Km Value of Various Kind of Luciferase Relative to ATP
[0109] ATP was added to a 1 mM D-luciferin solution (Tris-HCl (pH-8.0)) to obtain various kinds of solutions differing in ultimate concentration of ATP from each other, i.e. 10 μM, 20 μM, 40 μM, 80 μM, 160 μM, 320 μM, 640 μM, 1280 μM, respectively, thus preparing 8 kinds of solutions differing in ATP concentration.
[0110] Then, a 100 μg/ml luciferase solution was prepared by making use of 0.1M Tris-HCl (pH-8.0). Subsequently, the ATP solutions each having the aforementioned concentration were respectively aliquoted to a vessel having 96 wells, thus creating wells each containing 50 μl of the ATP solution.
[0111] Then, the luciferase solution was connected with a standard pump of luminometer, after which a program was prepared so as to initiate the measurement concurrent with the addition of 50 μl of the luciferase solution to each of the wells.
[0112] Subsequently, the program was started to measure the photon-count value at each ATP concentration. Based on the results obtained, Lineweaver-Burk plot and Hanes-Woolf plot were prepared to determine the Km value of each kind of luciferase relative to ATP.
[0113] (Discussion)
[0114] FIG. 5 shows the Km values that have been determined from the results of above experiments. FIG. 5 is a table showing the Km value of each kind of luciferase relative to D-luciferin and ATP. Incidentally, in FIG. 5 , the number described inside the parenthesis represents the Km value that was calculated by making use of the Hanes-Woolf plot and the number described outside the parenthesis represents the Km value that was calculated by making use of the Lineweaver-Burk plot.
[0115] Since the Km value of each kind of luciferase is treated in the same manner as Kd in general, it is conceivable that as the Km value becomes smaller, the affinity of luciferase to D-luciferin or ATP becomes higher. As shown in FIG. 5 , the ranking of the affinity of luciferase to D-luciferin was confirmed as being CBG>ELuc>GL3>CBR>Genji.
[0116] When the facts that CBG, CBR and ELuc are respectively luciferase originating from Hikari Kometsuki and GL3 and Genji are respectively luciferase originating from firefly are taken into consideration, there will be recognized the trend that the affinity to D-luciferin becomes higher in the Luciferase originated from Hikari Kometsuki.
[0117] Further, with respect to the luminescence pattern obtained from the measurement using a luminometer also, the results obtained from the luciferase originated from Hikari Kometsuki were found different from the results obtained from the firefly-derived luciferase. Specifically, while the luciferase originated from Hikari Kometsuki exhibited a peak luminescence intensity 5 to 6 seconds after the addition of luciferin, the firefly-derived luciferase was confirmed to exhibit a peak luminescence intensity 0.5 to 1 second after the addition of luciferin.
[0118] As described above, since luciferase is likely to be classified into a flash type (requiring a short time for luminescence) and a glow type (requiring a long time for luminescence) depending on the species of organism representing the origin of luciferase, a desirable type of luciferase can be selected depending on the purpose of measurement or observation.
[0119] Further, there is a report describing that the difference of luminescence pattern as described above can be generated due to differences in amino acid residue of luciferase (R218, F250, G315, T343, etc.) existing in the vicinity of D-luciferin- or ATP-bonding site, these differences being caused by the point mutation of P. pyralis (see Bruce R. Branchini et al., Biochemistry, 2003, 42, pp. 10429-10436).
[0120] Since the aforementioned amino acid residue is known as being capable of contributing to the decay rate, it has been found possible to prepare the luciferase that is capable of exhibiting a luminescence pattern which differs from the flash type or the glow type by making use of genetic engineering techniques while taking the amino acid residue in each kind of luciferase into consideration.
[0121] Meanwhile, the ranking of the affinity of luciferase to ATP has been confirmed as being CBG>CBR, GL3>ELuc>Genji. Namely, the results thus obtained indicate that ELuc and Genji were relatively low in affinity to ATP as compared with that of other kinds of luciferase.
[0122] In this case, there is a possibility that since a small degree of variations in quantity of ATP cannot be fully reflected to the quantity of luminescence in the case of GL3 which is high in susceptibility, the luminescence intensity will be retained constant until the quantity of ATP is greatly attenuated. Specifically, in the experiments conducted by the present inventor, pGL3 was transfected to HeLa cell and, by making use of FCCP (carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone) acting as an uncoupler, the production of ATP in mitochondria was suspended and then the luminescence intensity on this occasion was measured with time by making use of LUMINOVIEW (LV100) (trade name). However, the luminescence intensity was not attenuated even if the measurement was continued after the excitation thereof.
[0123] The cytoplasmic ATP of HeLa cell under the steady state is estimated as being 1.3 mM (see MV Zamaraeve et al., Cell Death and Differentiation, 2005, 12, pp. 1390-1397), so that if the luciferin-luciferase reaction is assumed as being abided by Michaelis-Menten equation, the reaction velocity of GL3 at this ATP concentration would be increased to about 85% of Vmax. Meanwhile, although it is reported that the concentration of cytoplasmic ATP after it was left to stand for 30 minutes after the treatment thereof with FCCP became about 50% of that of steady state (Takeshi Kubota et al., Biochimica et Biophysica Acta, 2005, 1744, pp. 19-28), the reaction velocity of GL3 in the reaction using 0.65 mM ATP is expected to be about 80% of Vmax. Namely, in the case of the measuring system using a cell wherein the quantity of manifestation of luciferase is caused to change, it is expected to be difficult to detect, by means of a CCD camera, the fluctuation of luminescence originating from a difference of 5% in reaction velocity as being the fluctuation in quantity of ATP.
[0124] Whereas, in the case of using the luciferase which is relatively low in affinity, the reaction velocity to be expected from Michaelis-Menten equation is slow, so that the same degree of difference in reaction velocity is caused to generate even when it is treated with drugs, thus making it possible to conclude that the aforementioned detection can be facilitated as compared with the case where GL3 is employed.
[0125] Namely, in the case of quantitatively measuring a substance existing at a ratio of more than a prescribed value in a biological sample such as ATP, it has been found possible to obtain a relatively large difference in reaction velocity and hence to facilitate the observation of a difference in luminescence intensity by suitably selecting a luminescence-associated material which is high in a Km value so as to prevent the concentration of the substance from approaching to the vicinity of Vmax in the Michaelis-Menten equation. On the occasion of measuring the ATP concentration inside a cell, it is preferable to estimate the quantity of ATP inside the cell and, based on this estimation, luciferase having an appropriate Km value may be selected. As described above, the low affinity (a high Km value) to ATP is an advantageous property on the occasion of measuring the ATP concentration inside a cell by making use of the luciferin-luciferase reaction.
[0126] The affinity to ATP in this case can be varied by means of the point mutation in the vicinity of ATP bonding site (see Bruce R. Branchini et al., Biochemistry, 2003, 42, pp. 10429-10436). Namely, an intracellular ATP-measuring system corresponding to many kinds of cells may be constructed by preparing a series of luciferase exhibiting various degrees of ATP affinity ranging from an intermediate affinity to a very low affinity (having Km values ranging from an intermediate Km value to a very high Km value). Incidentally, on the occasion of adjusting the ATP affinity by the introduction of a mutation into luciferase, it may be performed carefully so as to prevent the decrease of luminescence intensity.
[0127] The aforementioned method is directed, as an example, to an examination method wherein the luciferase which is low in affinity to a biological substance is used to measure or observe the substance for a long period of time when the substance is existed excessively in an organism. However, if the biological substance is existed only a very small quantity in an organism, the luciferase which is high in affinity to the substance may be selected. In this manner, the affinity to various kinds of biological substance existing in various degrees in an organism is respectively determined in advance and, based on the affinity thus determined, a suitable kind of luciferase is selected for any desired examination item, thereby making it possible to always perform the measurement or observation which is high in examination efficiency.
[0128] As explained above, as a result of extensive studies performed by the present inventor, it has been found out that it is possible to perform excellent measurement by selecting the luciferase which is low in affinity to a substance to be examined as the substance is existed excessively in an organism, especially a cell, as in the case of ATP. Especially, it has been found out as a result of the studies made on the affinity to ATP that it is possible to accurately measure quantitative fluctuation in an organism by selecting the luciferase having a Km value of not less than 364 μM, preferably not less than 500 μM. Further, when the Km value is adjusted through the modification of gene, it is possible to utilize also the luciferase which inherently exhibits a Km value falling out of the aforementioned range before the modification thereof. When the luciferase having such a Km value is utilized for luminously labeling a biological sample including a plurality of cells, it becomes possible, through the picking up of the luminescent picture image based on the luminescence of organism, to measure the luminescence intensity of each of the cells. Furthermore, it is possible to perform the analysis including the analysis of morphological fluctuation of each of cells on the basis of the luminescent image. Therefore, the measuring method of the present invention can be also provided as being useful in an application for accurately specifying the morphological fluctuation of each of cells such as shrinking that has been caused by the induction of apoptosis, etc. in conformity with the stimulation using a drug for example. In this case, the stimulation to be applied to an object to be analyzed may include physical energy such as electricity, light, magnetism, ultrasonic wave, etc. other than the addition or dosing of a chemical material such as a drug.
[0129] Namely, in the measurement of biological substance by making use of luciferase, the affinity to an object to be measured can be suitably combined with the affinity to a luminescent substrate, thereby making it possible to perform accurate quantitative measurement (especially, the measurement of fluctuation of concentration) under appropriate measuring conditions even if the object is enabled to excessively existed in an organism. This indicates in turn that the measuring method of the present invention is applicable to any desired examination for detecting very weak fluctuation in an organism or to any desired examination based on fluctuation in luminescence intensity of a substance which is capable of emitting a weak light such as a cell.
Example 2
Comparison of Enzymological Properties Between Yaeyama Hime Firefly Originated Luciferase and Each of Other Kinds Luciferase
[0130] Followings are explanation with regard to the enzymological properties of Yaeyama Hime firefly (scientific name: Luciola filiformis yayeyamana) originated luciferase which has been newly found and extracted by the present inventor and each of other kinds of luciferase described above and with regard to the application thereof.
[0131] As a background of this example, there has been a problem that since the luciferase available in the market is already modified by a genetic engineering method, it is difficult to expect any further technical progress. With a view to get out of this difficulty, the screening of novel luciferase was conducted by the present inventor. As a result, it was succeeded to obtain the luciferase gene (Sequence No. 1) originated from Yaeyama Hime firefly. Therefore, the determination of the enzymological properties of the luciferase of Yaeyama Hime firefly was performed. Namely, in this example, the determination of the enzymological properties (Km values thereof to D-luciferin and ATP) of the newly obtained luciferase originated from Yaeyama Hime firefly was performed. Further, for the purpose of comparison, the determination of the enzymological properties of various kinds of luciferase (CBG, CBR, ELuc, Genji, GL3) available from the market was concurrently executed.
[0132] From the sequence of gene, several kinds of firefly belonging to Luciola have been known to live in Japan. As a result of the following experiments conducted to Genji firefly (scientific name: Luciola cruciata, the name of luciferase will be referred to as Genji in the present specification), the gene arrangement thereof being already known, differences in Km value were found out. The present invention has taken notice of this differences in Km value and hence one of important subject matters of the present invention is to utilize the luciferase as a luminescent marker in conformity with purposes.
Experiment Method 1
Calculation of the Concentration of the Stock Solutions of D-Luciferin and of ATP
[0133] First of all, in order to calculate the concentration of D-luciferin, the ultraviolet/visible light absorption spectrum of D-luciferase was measured. In this measurement, the spectrum was measured using a diluted (by 4000 times) solution (in 0.1M Citrate/0.2M Na 2 HPO 4 buffer, pH=5.0) of D-luciferin (Promega Co., Ltd.) stock solution (about 100 mM). As for the blank, the buffer described above was employed. FIG. 6 illustrates the ultraviolet/visible light absorption spectrum of D-luciferase.
[0134] By making use of the absorbency (328 nm, 0.467±0.006, n=10) obtained from the spectrum of FIG. 6 , the concentration of the D-luciferin stock solution was calculated (D-luciferin: λd max=328 nm, εc=18200, pH=5.0). As a result of the calculation, the concentration of the D-luciferin stock solution was found as being 102.6 mM.
[0135] Then, in order to calculate the concentration of ATP, the ultraviolet/visible light absorption spectrum of ATP was measured. In this measurement, the spectrum was measured using a diluted (by 2000 times) solution (in 0.1M Citrate/0.2M Na 2 HPO 4 buffer, pH=7.0) of ATP stock solution (about 100 mM). As for the blank, the buffer described above was employed. FIG. 7 illustrates the ultraviolet/visible light absorption spectrum of ATP.
[0136] By making use of the absorbency (259 nm, 0.359±0.004, n=10) obtained from the spectrum of FIG. 7 , the concentration of the ATP stock solution was calculated (ATP: λ max =259 nm, s=15400, pH=7.0). As a result of the calculation, the concentration of the ATP stock solution was found as being 46.6 mM.
Experiment Method 2
Purification of Various Kinds of Luciferase
[0137] The purification of luciferase was performed according to the following procedure after establishing a luciferase-purification system utilizing affinity chromatography.
[0138] (Procedure of Transfection of Luciferase Expression Vector to Coli Bacillus)
[0139] First of all, 0.5 μL of luciferase expression vector was introduced into 50 μL of coli bacillus (JM109(DE3)). Then, the resultant liquid was subjected to a thermostatic treatment consisting of ice-cooling for 10 minutes, heating at 42° C. for one minute and ice-cooling for two minutes. Then, 2 μL of the resultant coli bacillus solution was added to 1 mL of an SOC culture medium.
[0140] Subsequently, the resultant solution of coli bacillus/SOC culture medium mixture was subjected to shaking at 37° C. for 20 minutes and to incubation. Then, 100 μL of the resultant solution was streaked onto an LB culture medium plate (Ampicillin 100 μg/mL+) and subjected to incubation overnight at 37° C.
[0141] (Purification of Luciferase by Means of Affinity Chromatography)
[0142] Then, the coli bacillus was fractured to obtain a raw extract, from which luciferase was purified by means of affinity chromatography.
[0143] Namely, first of all, a suspension of coli bacillus was subjected to centrifugal separation at 15000 rpm for 5 minutes to recover the pellets of coli bacillus, which was then suspended in 10 mL of TBS cooled to 4° C. Subsequently, by making use of French Pressure Cell, the fungus body was fractured. The resultant fungus body-fractured liquid was subjected to centrifugal separation (15000 rpm, 10 minutes) to remove settled residues and to recover a supernatant liquid.
[0144] Subsequently, 2 mL of TBS was added to a column having 2 mL of bed volume and subjected to filtration. Then, 500 μL of a Ni-Agar suspension and 2 mL of TBS were added to the column and the TBS was allowed to gravitationally drop (column equilibration). The supernatant liquid thus recovered was added to the column and allowed to gravitationally drop. Incidentally, the operation until the drop of the supernatant liquid was completed was performed inside a refrigerator at a temperature of 4° C.
[0145] Then, by making use of 1 mL of a 50 mM imidazole/TBS solution, the column was washed. Further, 2 mL of a 500 mM imidazole/TBS solution was added to the column to elute luciferase. The resultant elute was recovered in a 10 mL tube and immediately ice-cooled. Subsequently, the concentration of elute was performed by means of ultrafiltration.
[0146] Subsequently, the elute was moved 400 μL by 400 μL to a centrifugal concentration tube (SUPREC™-02, available from TaKaRa Co., Ltd. (exclusion limit molecular weight: 30,000)) and then subjected to centrifugal separation (5000 rpm, 30 minutes) until the elute was concentrated to about 100 μL. Thereafter, the absorbency of the concentrated elute was measured by means of a plate reader and the concentration of luciferase was calculated from the calibration curve which was prepared by making use of BSA. After finishing the calculation of concentration, the solution of luciferase was formulated as a 50% Glycerol solution and preserved at −20° C.
Experiment Method 3
Calculation of Km Value of Various Kind of Luciferase Relative to D-Luciferin
[0147] First of all, a solution of 4 mM ATP and a solution of 8 mM MgSO 4 (in 0.1M Tris-HCl (pH-8.0)) were prepared. Then, D-luciferin was added to the ATP solution to obtain various kinds of solutions differing in ultimate concentration of D-luciferin from each other, i.e. 5 μM, 10 μM, 20 μM, 40 μM, 80 μM, 160 μM, 320 μM, 640 μM, respectively, thus preparing 8 kinds of solutions differing in concentration of D-luciferin from each other.
[0148] Then, a 100 μg/ml luciferase solution was prepared by making use of 0.1M Tris-HCl (pH-8.0) and D-luciferin solutions having the aforementioned concentrations were respectively aliquoted to a vessel having 96 wells, thus creating wells each containing 50 μl of D-luciferin solution.
[0149] Then, the luciferase solution was connected with a standard pump of luminometer, after which a program was prepared so as to initiate the measurement concurrent with the addition of 50 μl of the luciferase solution to each of the wells.
[0150] Subsequently, the program was started to measure the photon-count value at each D-luciferin concentration. Incidentally, the measurement was repeated five times at each concentration of D-luciferin.
[0151] Based on the results obtained, Lineweaver-Burk plot and Hanes-Woolf plot were prepared. In this case, the Lineweaver-Burk plot can be represented by the following formula (3) and the Hanes-Woolf plot can be represented by the following formula (4). Incidentally, the photon-count value immediately after the addition of an enzyme solution was defined as the initial velocity in the preparation of each of these plots.
[0000]
Formula
(
3
)
1
v
=
Km
v
max
×
1
[
S
]
+
1
v
max
Formula
(
3
)
Formula
(
4
)
[
S
]
v
=
Km
v
max
+
[
S
]
v
max
Formula
(
4
)
[0152] (V: Reaction velocity; V MAX : Maximum velocity; [S]: Concentration of substrate; and Km: Michaelis constant)
[0153] Graphs illustrating the fluctuation of luminescence intensity of each kind of luciferase due to an increase in concentration of D-luciferin, the results of Lineweaver-Burk plot and the results of Hanes-Woolf plot are illustrated in FIGS. 8 to 25 .
[0154] Namely, FIG. 8 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of CBG. FIG. 9 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of CBG. FIG. 10 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of CBG.
[0155] As a result of these measurements, the Km value of CBG relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 10.5 μM and the Km value of CBG relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 10.5 μM.
[0156] Further, in the case of CBR, the results were obtained as follows. Namely, FIG. 11 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of CBR. FIG. 12 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of CBR. FIG. 13 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of CBR.
[0157] As a result of these measurements, the Km value of CBR relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 36.4 μM and the Km value of CBR relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 63.8 μM.
[0158] Further, in the case of ELuc, the results were obtained as follows. Namely, FIG. 14 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of ELuc. FIG. 15 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of ELuc. FIG. 16 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of ELuc.
[0159] As a result of these measurements, the Km value of ELuc relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 15.0 μM and the Km value of ELuc relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 15.0 μM.
[0160] Further, in the case of Genji, the results were obtained as follows. Namely, FIG. 17 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of Genji. FIG. 18 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of Genji. FIG. 19 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of Genji,
[0161] As a result of these measurements, the Km value of Genji relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 75.0 μM and the Km value of Genji relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 75.0 μM.
[0162] Further, in the case of GL3, the results were obtained as follows. Namely, FIG. 20 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of GL3. FIG. 21 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of GL3. FIG. 22 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of GL3.
[0163] As a result of these measurements, the Km value of GL3 relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 33.3 μM and the Km value of GL3 relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 25.0 μM.
[0164] Further, in the case of Yaeyama (luciferase originated from Yaeyama Hime firefly), the results were obtained as follows. Namely, FIG. 23 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of D-luciferin in the case of Yaeyama. FIG. 24 shows the Lineweaver-Burk plot, relative to the concentration of D-luciferin, of Yaeyama. FIG. 25 shows the Hanes-Woolf plot, relative to the concentration of D-luciferin, of Yaeyama.
[0165] As a result of these measurements, the Km value of Yaeyama relative to D-luciferin as it was calculated from the Lineweaver-Burk plot was 100 μM and the Km value of Yaeyama relative to D-luciferin as it was calculated from the Hanes-Woolf plot was 100 μM.
Experiment Method 4
Calculation of Km Value of Various Kind of Luciferase Relative to ATP
[0166] In order to perform the calculation of Km value of each kind of the luciferase to ATP, an 8 mM MgSO 4 (in 0.1M Tris-HCl (pH=8.0)) solution of 1 mM D-luciferin was prepared at first.
[0167] Then, ATP was added to this D-luciferin to obtain various kinds of solutions differing in ultimate concentration of ATP from each other, i.e. 10 μM, 20 μM, 40 μM, 80 μM, 160 μM, 320 μM, 640 μM, 1280 μM, respectively, thus preparing 8 kinds of solutions differing in concentration of ATP from each other. Then, a 0.1M Tris-HCl (pH=8.0) solution of 100 μg/ml luciferase was prepared. The ATP solutions having the aforementioned concentrations were respectively aliquoted to a vessel having 96 wells, thus creating wells each containing 50 μl of the ATP solution.
[0168] Then, the luciferase solution was connected with a standard pump of luminometer, after which a program was prepared so as to initiate the measurement concurrent with the addition of 50 μl of the luciferase solution to each of the wells.
[0169] Subsequently, the program was started to measure the photon-count value at each ATP concentration. Incidentally, the measurement was repeated five times at each concentration of ATP.
[0170] Based on the results obtained, Lineweaver-Burk plot and Hanes-Woolf plot were prepared.
[0171] Graphs illustrating the fluctuation of luminescence intensity of each kind of luciferase due to an increase in concentration of ATP, the results of Lineweaver-Burk plot and the results of Hanes-Woolf plot are illustrated in FIGS. 26 to 43 .
[0172] Namely, FIG. 26 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of CBG. FIG. 27 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of CBG. FIG. 28 shows the Hanes-Woolf plot, relative to the concentration of ATP, of CBG.
[0173] As a result of these measurements, the Km value of CBG relative to ATP as it was calculated from the Lineweaver-Burk plot was 200 μM and the Km value of CBG relative to ATP as it was calculated from the Hanes-Woolf plot was 290 μM.
[0174] Further, in the case of CBR, the results were obtained as follows. Namely, FIG. 29 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of CBR. FIG. 30 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of CBR. FIG. 31 shows the Hanes-Woolf plot, relative to the concentration of ATP, of CBR.
[0175] As a result of these measurements, the Km value of CBR relative to ATP as it was calculated from the Lineweaver-Burk plot was 110 μM and the Km value of CBR relative to ATP as it was calculated from the Hanes-Woolf plot was 130 μM.
[0176] Further, in the case of ELuc, the results were obtained as follows. Namely, FIG. 32 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of ELuc. FIG. 33 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of ELuc. FIG. 34 shows the Hanes-Woolf plot, relative to the concentration of ATP, of ELuc.
[0177] As a result of these measurements, the Km value of ELuc relative to ATP as it was calculated from the Lineweaver-Burk plot was 364 μM and the Km value of ELuc relative to ATP as it was calculated from the Hanes-Woolf plot was 250 μM.
[0178] Further, in the case of Genji, the results were obtained as follows. Namely, FIG. 35 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of Genji. FIG. 36 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of Genji. FIG. 37 shows the Hanes-Woolf plot, relative to the concentration of ATP, of Genji.
[0179] As a result of these measurements, the Km value of Genji relative to ATP as it was calculated from the Lineweaver-Burk plot was 500 μM and the Km value of Genji relative to ATP as it was calculated from the Hanes-Woolf plot was 500 μM.
[0180] Further, in the case of GL3, the results were obtained as follows. Namely, FIG. 38 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of GL3. FIG. 39 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of GL3. FIG. 40 shows the Hanes-Woolf plot, relative to the concentration of ATP, of GL3.
[0181] As a result of these measurements, the Km value of GL3 relative to ATP as it was calculated from the Lineweaver-Burk plot was 200 μM and the Km value of GL3 relative to ATP as it was calculated from the Hanes-Woolf plot was 200 μM.
[0182] Further, in the case of Yaeyama, the results were obtained as follows. Namely, FIG. 41 shows a graph illustrating the fluctuation of luminescence intensity due to an increase in concentration of ATP in the case of Yaeyama. FIG. 42 shows the Lineweaver-Burk plot, relative to the concentration of ATP, of Yaeyama. FIG. 43 shows the Hanes-Woolf plot, relative to the concentration of ATP, of Yaeyama.
[0183] As a result of these measurements, the Km value of Yaeyama relative to ATP as it was calculated from the Lineweaver-Burk plot was 400 μM and the Km value of Yaeyama relative to ATP as it was calculated from the Hanes-Woolf plot was 400 μM.
[0184] (Discussion)
[0185] The Lineweaver-Burk plot and the Hanes-Woolf plot were prepared from the photon count values obtained by the luminometer and, based on these plots, the Km values were calculated. FIG. 44 shows a summary of these results of calculation of the Km values. In FIG. 44 , the number described inside the parenthesis represents the Km value that was calculated by making use of the Hanes-Woolf plot.
[0186] Since the Km value of each kind of luciferase is treated in the same manner as Kd in general, it is conceivable that as the Km value becomes smaller, the affinity of luciferase to D-luciferin or ATP becomes higher. Namely, the ranking of the affinity of luciferase to D-luciferin was confirmed as being CBG>ELuc>GL3>CBR>Genji>Yaeyama.
[0187] When the facts that CBG, CBR and ELuc are respectively luciferase originating from Hikari Kometsuki and GL3, Genji and Yaeyama are respectively luciferase originating from firefly are taken into consideration, there will be recognized the trend that the affinity to D-luciferin becomes higher in the Luciferase originated from Hikari Kometsuki.
[0188] Although data are not shown herein, the results obtained from the Luciferase originated from Hikari Kometsuki were found different from the results obtained from the firefly-derived luciferase with respect also to the luminescence pattern obtained from the measurement using a luminometer. Specifically, while the Luciferase originated from Hikari Kometsuki exhibited a peak luminescence intensity 5 to 6 seconds after the addition of luciferin, i.e. so-called glow type luminescence, the firefly-derived luciferase was confirmed to exhibit a peak luminescence intensity 0.5 to 1 second after the addition of luciferin, i.e. so-called flash type luminescence. With respect to the Luciferase originated from Yaeyama which was obtained by the present inventor at this time, since it exhibited a peak luminescence intensity 0.5 to 1 second after the addition of luciferin, this Luciferase was confirmed as being of flash type.
[0189] Further, there is a report describing that the difference of luminescence pattern as described above can be generated due to differences in amino acid residue of luciferase (R218, F250, G315, T343, etc.) existing in the vicinity of D-luciferin- or ATP-bonding site, these differences being caused by the point mutation of P. pyralis (see Bruce R. Branchini et al., Biochemistry, 2003, 42, pp. 10429-10436).
[0190] Since the aforementioned amino acid residue is known as being capable of contributing to the decay rate, it has been found possible to prepare the luciferase that is capable of exhibiting a luminescence pattern which differs from the flash type or the glow type by making use of genetic engineering techniques while taking the amino acid residue in each kind of luciferase into consideration.
[0191] Meanwhile, the ranking of the affinity of luciferase to ATP has been confirmed as being CBG>CBR, GL3>ELuc>Yaeyama>Genji. Namely, the results thus obtained indicate that, although it is inferior as compared with Genji, Yaeyama was relatively low in affinity to ATP as compared with that of other kinds of luciferase. This low affinity to ATP is an advantageous property on the occasion of quantitatively determining the intercellular ATP concentration by making use of the luciferin-luciferase reaction.
[0192] In this case, there is a possibility that since a small degree of variations in quantity of ATP cannot be fully reflected to the quantity of luminescence in the case of GL3 which is high in susceptibility, the luminescence intensity will be retained constant until the quantity of ATP is greatly attenuated. Specifically, in the experiments conducted by the present inventor, pGL3 was transfected to HeLa cell and, by making use of FCCP acting as an uncoupler, the production of ATP in mitochondria was suspended and then the luminescence intensity on this occasion was measured with time by making use of LUMINOVIEW (LV100) (trade name). However, the luminescence intensity was not attenuated even if the measurement was continued after the excitation thereof.
[0193] The cytoplasmic ATP of HeLa cell under the steady state is estimated as being 1.3 mM (see MV Zamaraeve et al., Cell Death and Differentiation, 2005, 12, pp. 1390-1397), so that if the luciferin-luciferase reaction is assumed as being abided by Michaelis-Menten equation, the reaction velocity of GL3 at this ATP concentration would be increased to about 85% of Vmax. Meanwhile, although it is reported that the concentration of cytoplasmic ATP after it was left to stand for 30 minutes after the treatment thereof with FCCP became about 50% of that of steady state (see Takeshi Kubota et al., Biochimica et Biophysica Acta, 2005, 1744, pp. 19-28), the reaction velocity of GL3 in the reaction using 0.65 mM ATP is expected to be about 80% of Vmax. Therefore, in the case of the measuring system using a cell wherein the quantity of manifestation of luciferase is caused to change, it is expected to be difficult to detect, by means of a CCD camera, the fluctuation of luminescence originating from a difference of 5% in reaction velocity as being the fluctuation in quantity of ATP.
[0194] Meanwhile, in the case of using Yaeyama, a reaction velocity corresponding to about 80% of Vmax in the case of 1.35 mM ATP and a reaction velocity corresponding to about 60% of Vmax in the case of 0.65 mM ATP are expected to be realized in view of the Michaelis-Menten equation, so that a difference of 20% in reaction velocity would be caused to generate as it is treated with drugs (FCCP treatment), thus finding that the detection can be facilitated as compared with the case where GL3 is employed. Namely, Yaeyama is found capable of exhibiting the most advantageous Km value in the luminescence imaging method of ATP. Further, when the above-described examples of GL3 and Yaeyama are taken into account, it is preferable to select the luciferase after estimating the quantity of ATP inside the cell on the occasion of measuring the intercellular ATP concentration.
[0195] The affinity to ATP in this case can be varied by means of the point mutation in the vicinity of ATP bonding site (see Bruce R. Branchini et al., Biochemistry, 2003, 42, pp. 10429-10436). Namely, by preparing a series of luciferase exhibiting various degrees of ATP affinity ranging from an intermediate affinity to a very low affinity (having Km values ranging from an intermediate Km value to a very high Km value), an intracellular ATP-measuring system corresponding to many kinds of cells can be constructed. Incidentally, since it is known that the luminescence intensity is caused to decrease in the case of the luciferase which has been modified through the introduction of mutation, the Yaeyama may be modified so as to adjust the ATP affinity while taking into consideration the retention of high luminescence intensity.
Example 3
[0196] In this example 3, the object of experiment was directed to a plurality of HeLa cells having a luciferase gene introduced therein. By making use of luminometer (Chronos, ATTO Co., Ltd.), the luminescence of the HeLa cells to be induced by drug stimulation was tracked with time and the results obtained were compared with the quantity of fluctuation in luminescence that had been brought about by the luciferase gene.
[0197] A drug Staurosporine (STS) is known as being capable of obstructing PKC and of inducing apoptosis. Further, it is reported that once apoptosis has been induced by the STS, the intercellular ATP concentration is caused to increase at the initial stage of apoptosis (see MV Zamaraeva et al., Cell Death and Differentiation (2005), 12, pp. 1390-1397). In this example, the increase of the intercellular ATP concentration on the occasion of the induction of apoptosis into the HeLa cells by making use of the STS was detected by the increase of luminescence to be brought about by the ELuc and GL3, and the results obtained were compared with each other.
[0198] (Procedures of Experiment)
[0199] (1) A SV40 promoter/Emerald Luc expressing vector (Tohyobou Co., Ltd.) and a SV40 promotor/GL3 expressing vector were respectively introduced into HeLa cells which had been seeded in a glass bottom dish, thereby preparing the HeLa cells which were capable of constantly expressing luciferase.
[0200] (2) D-luciferin was added to the above-described samples to obtain the samples containing D-luciferin at an ultimate concentration of 0.5 mM. The resultant samples were left to stand for one hour in an incubator.
[0201] (3) The samples were set in a luminometer and then Staurosporine (STS) was added to these samples so as to make the ultimate concentration into 4 μM.
[0202] (4) After the addition of the drug, the measurement using the luminometer was initiated and fluctuation in luminescence after the stimulation using the drug were tracked with time.
[0203] As a result, fluctuation in luminescence intensity after the stimulation with STS were obtained as shown in FIG. 45 and FIG. 46 . In this case, FIG. 45 is a graph showing the fluctuation of luminescence of ELuc obtained in the measurement of the quantity of intercellular ATP measured using a luminometer (Chronos) and FIG. 46 is a graph showing the fluctuation of luminescence of GL3 obtained in the measurement of the quantity of intercellular ATP measured using a luminometer (Chronos). This experiment was performed under the conditions wherein OPTI-MEM and 0.5 mM D-luciferin were used in the measurement using Chronos (ATTO Co., Ltd.) (36° C., 10-second integration data). After the stimulation using 4 μM Staurosporine (STS), the measurement was started.
[0204] As shown in FIG. 45 and FIG. 46 , it will be recognized through the comparison between the fluctuation of luminescence of ELuc and GL3 that ELuc was more preferable in increasing the magnitude of fluctuation, thereby facilitating the detection using a luminometer. These results indicate that the employment of luciferase exhibiting a lower affinity to ATP is advantageous in the measurement of the fluctuation of ATP.
Example 4
[0205] In this example 4, the object of experiment was directed to a plurality of HeLa cells having a luciferase gene introduced therein. By making use of LV200 (Olympus Co., Ltd.) representing a luminescence imaging system which was capable of executing the picking up/observation of three kinds of images, i.e. a fluorescent-transmitting image, a luminescent (chemical luminescence and/or biological luminescence) image and a transmitting bright visual field image, the luminescence of specific HeLa cells to be induced by drug stimulation was tracked with time and the luminescence intensity thereof was tracked. This luminescence imaging system was equipped with a component which was capable of cultivating a sample including cells, with a common pick up component (an objective lens, an imaging lens and a CCD camera), and an illumination system which was capable of executing the irradiation for exciting fluorescence and illumination of bright visual field. It is possible, with this system, to selectively obtaining an image from these three kinds of image and to individually display or analyze each of these images in accordance with the instruction of an operator. Therefore, it is possible for an operator to optionally give instructions through an interface of the system or to output the results of the analysis of these images.
[0206] (Procedures of Experiment)
[0207] (1) A SV40 promoter/Emerald Luc expressing vector (Tohyobou Co., Ltd.) was introduced into HeLa cells which had been seeded in a glass bottom dish, thereby preparing the HeLa cells which were capable of constantly expressing luciferase.
[0208] (2) D-luciferin was added to the above-described samples to obtain the samples containing D-luciferin at an ultimate concentration of 0.5 mM. The resultant samples were left to stand for one hour in an incubator.
[0209] (3) The samples were set in a luminescence imaging apparatus and then Staurosporine (STS) was added to these samples so as to make the ultimate concentration into 4 μM.
[0210] (4) After the addition of the drug, the measurement using the luminometer was initiated and fluctuation in luminescence after the stimulation using the drug were tracked with time.
[0211] As a result, it was possible to observe the luminescent image and the fluctuation in luminescence intensity as shown in FIG. 47 and FIG. 48 . In this case, FIG. 47 is a graph showing a luminescent image in an ELuc expressing HeLa cell which was obtained immediately after the drug stimulation. The conditions for this experiment were as follows. By making use of 0.5 mM D-luciferin/OPTI-MEM, the measurement of ELuc control vector-introduced HeLa cell (seeded in a glass bottom dish) was performed using LV200 (Olympus Co., Ltd.). As for the CCD camera, an ImagEM was used. The picking up was performed under the conditions of: EM-Gain 200, binning 1×1, 10 sec exposure, 15 sec intervals, 40× objective lens. The measurement was started after the stimulation using 4 μM Staurosporine (STS). FIG. 48 is a graph showing the fluctuation of luminescence intensity after the STS stimulation in each of cells (ELuc expressing HeLa cells: 1 to 7 ) that has been analyzed from the images ( 1 to 7 ) each rectangularly encircled in FIG. 47 .
[0212] As shown in FIG. 48 , it has been found possible to track with time the luminescence of a specific HeLa cell by means of luminescent imaging and by making use of the luciferase which is low in affinity to ATP. Further, herein, FIG. 49 shows one example illustrating a luminescence image which was photographed prior to the stimulation of cell (prior to the induction of apoptosis by the stimulation of cell) according to the experiment procedures and under the experimental conditions described above. Further, FIG. 50 shows images which are designated as three measuring regions (ROI: regions of interest) in the luminescent image shown FIG. 49 .
[0213] As shown in FIG. 49 , according to the experiment procedures and under the experimental conditions described above, it was possible to obtain a luminescent image (magnification: 100 times) related to a single cell. In this luminescent image, three cells are photographed. Among these cells, the cell located at the center is photographed in such a manner that the upper portion thereof is the brightest, the lower portion thereof is the next in brightness to the upper portion, and the intermediate portion thereof is somewhat dark. Then, as shown in FIG. 50 , Three measuring regions (ROI) were designated from the luminescent image of FIG. 49 and the brightness of luminescence of each pixel group (49 pixels) in three regions was measured. Herein, FIG. 51 shows the values of luminescent brightness in three regions and the graph thereof. Incidentally, the values of luminescent brightness are represented by an arbitrary unit, so that the numbers “ 1 ”, “ 2 ” and “ 3 ” in the lower table of FIG. 51 represent designated three measuring regions and the number “ 4 ” represents the background (an optional designated region containing no cell in the image). Further, “Total” in the table represents a total of the values of luminescent brightness in 49 pixels. “Average” in the table represents an average of the values of luminescent brightness of unit pixel. The graph of FIG. 50 illustrates the results obtained by correcting the average of the values of luminescent brightness with an average (=19.6939) of the values of luminescent brightness of the background.
[0214] When the ATP is consumed in a state where cells are still alive, the luminescence to be derived therefrom would become dark. Therefore, in the region where biological metabolic activity is weak in the same cell, the ATP can be hardly consumed, resulting in the generation of bright luminescence. As shown in FIG. 50 , it has been found possible to quantitatively perform comparative analysis by executing only one picking up of the distribution of substance (ATP) to be measured, the distribution extending from a high concentration to a low concentration. When a tracking experiment was performed after the stimulation of the same cell, the brightness was gradually increased in every designated regions, thus indicating the deterioration of biological metabolic activity. Further, it was also confirmed that as the designated region became darker, the luminescence could be more quickly turned into higher brightness. As described above, according to this example 4, the distribution of the substance to be measured can be quantified among a plurality of cells or in each of the regions within the same cell, thereby making it possible to track the luminescence with time. In view of these results, it is possible, according to the luminescence measuring method of the present invention, to realize the execution of luminescence analysis of each of emitting sites exhibiting a wide dynamic range in an object to be analyzed (for example, a biological tissue or a cultivated cell group (or a segment of various internal organs)) which is positioned within the visual field of observation. Therefore, it is possible to execute, while minimizing the damage to an organism, the quantitative kinetic analysis of a plurality of sites in a single object to be analyzed and/or each of a plurality of objects to be analyzed with respect to biological active substances each exhibiting diverse dynamic range (for example, ATP, calcium ion, cAMP). Further, since the dynamic range can be altered in conformity with the Km value, it is possible to execute quantitative measurement in conformity with the quantity of substance and to adjust the luminescence intensity so as to prevent the generation of an extreme difference in luminescence intensity. As a result, it is possible to concurrently perform the tests of various items by making use of the same weak-light detecting apparatus.
[0215] As described above, the luminescence measuring method and the luminescence measuring system according to the present invention can be suitably applied to various fields such as a biological field, a pharmaceutical field, a medical field, etc.
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Disclosed is a luminescence measuring method which can produce a luminous intensity depending on the amount of a substance to be measured even when the substance occurs in a biological sample in an amount equal to or more than a given amount, and which can achieve quantitative measurement. The method is characterized by includes preparing a biological sample containing a luminescence-associated protein which is can react with a substance occurring in the biological sample in amount equal to or more than a given amount and which has a Km value equal to or higher than a predetermined value so that the luminous intensity can be quantified depending on the amount of the substance, measuring the luminescence intensity emitted from the biological sample, and outputting a result of the measurement on a regions and/or part of the biological sample.
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The present invention refers to a divider for foldable cardboard boxes and a method for manufacturing said divider, made up of an assembly of sheets of cardboard or other similar material, joined to each other in perpendicular positions so that they make up small cells or compartments for holding bottles or similar fragile objects, perfectly separated from each other.
BACKGROUND OF THE INVENTION
Known in the art are dividers for foldable cardboard boxes formed by assemblies of sheets or strips provided with complementary cuts for slotting in the intercrossed sheets. In these known embodiments, only some of the sheets are glued to an internal side of the box; the other sheets are attached only to those which are glued to the box, but are not themselves attached to it.
These dividers are configured in such a way that they are folded at the same time as the box, though the fact that not all the sheets are attached to the sides thereof provokes that the divider moves out of its correct position, which creates difficulties for folding and unfolding it.
Another type of known divider is made up of a plurality of cardboard sheets provided with cutting lines and folding lines which serve to form flaps and strips in directions perpendicular to the flaps, those of one sheet being glued to those of the sheet immediately adjacent to it, so that they can be folded and unfolded at will, while the strips of the sheets situated at the ends of the assembly are glued to the sides of the box.
Although these dividers have advantages over the traditional dividers formed by sheets or strips with cuts to slot them into intercrossed position, they are rather slow to manufacture and the process must be implemented using precut sheets which are later submitted to a process of die-cutting, folding and gluing. The known dividers are usually formed from ridged cardboard sheets whose rigidity prevents feed from bobbins, for which reason supply must be implemented, as stated above, in the form of precut sheets, which means that the entire manufacturing process cannot be implemented continuously.
DESCRIPTION OF THE INVENTION
The divider for cardboard boxes and a method for manufacturing the divider object of the present invention have been designed in order to solve the disadvantages outlined.
The divider is made up of an assembly of strips or sheets of cardboard or similar material arranged in positions perpendicular to each other to form a plurality of compartments, at least some of which sheets or strips can be glued onto two opposite sides of the box. On the basis of this general embodiment, the divider is characterized in that it comprises an assembly of sheets provided with transverse fold lines, which make up bands folded in perpendicular directions with respect to bands juxtaposed and glued to the immediately adjacent sheets. The ends of the sheets which are situated on at least two opposite sides of the assembly are provided with flap-like bands folded transversally, those on each side being coplanar, glued to as many opposite sides of a box.
In a possible embodiment, the folded flaps of at least two opposite sides of the assembly are glued to some sheets which are in turn juxtaposed on the corresponding sides of the box.
Advantageously, one of the ends of each sheet situated on the opposite sides of the divider has one of its ends resting against the corresponding side of the box, in order to keep the divider unfolded.
At least one of the longitudinal edges of the sheets is provided with recesses which narrow progressively from the aforesaid edges.
The method for manufacturing dividers for foldable cardboard boxes comprises continuously feeding strips of flexible material which move along a path, said strips being provided with longitudinal grooves which will form fold lines in one or the other direction. These lines divide the strips into longitudinal bands of different widths, on at least some of which glue is placed. The strips are situated in different planes at the start of their travel, and as they move downstream they converge progressively until they are overlapped on each other and glued under pressure, each strip to those immediately adjacent, in positions which are laterally offset from each other, in order to form an assembly of strips overlapped and glued, which is then subjected to at least one transverse cutting operation to provide pieces which will constitute the folded dividers which will be glued to at least two opposite sides of a box.
In a more specific embodiment, the glue is applied in bands, the bands of each sheet being offset with respect to those of the following sheets according to several imaginary lines in a diagonal direction with respect to the assembly of sheets.
In a possible embodiment, the assembly of overlapped and glued strips is cut along straight lines.
Provision has also been made for the assembly of overlapped and glued strips being cut along lines which form recesses and projections.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of all that is set out in this specification, some drawings are attached which, solely by way of example, show a practical example of embodiment of the method for manufacturing the divider and of the divider assembly obtained using it.
In these drawings, FIG. 1 is a schematic perspective view showing the steps of the method; FIG. 2 is a schematic cross section of the glued strips before they are overlapped; FIG. 3 shows schematically the cutting into pieces of some sections of the precut glued strips, into shorter sections which constitute the folded dividers; FIG. 4 shows a folded divider at a larger scale; FIG. 5 is a view similar to that of FIG. 4, but with a folded divider provided with angular recesses on one of the longitudinal edges of the sheets and projections on the opposite edge; FIG. 6 is a perspective view of a folded divider with folded flaps on two opposite sides; FIG. 7 is a view of an unfolded divider, provided on two opposite sides with two end sheets glued onto other folded flaps; FIG. 8 is a view similar to that of FIG. 7, showing a divider provided with sheets on all four sides, while FIG. 9 is a plan view of a divider of the version illustrated in FIG. 7, situated inside a box.
DESCRIPTION OF A PREFERRED EMBODIMENT
The divider for foldable cardboard boxes can be obtained by a manufacturing method which comprises a continuous displacement of an assembly or group of laminar cardboard strips -1- fed from as many bobbins (not shown) along a set path. At the beginning of this path the strips -1- are situated in different and separate planes, advantageously parallel to each other (FIGS. 1 and 2), but laterally offset from each other (FIG. 2). All the strips, or at least all of them less some strips -1a- which are on the end sides of the group (as in the version illustrated in FIGS. 1 and 2), present either from the start, or from one point of their initial travel, some longitudinal grooves -2- which divide them into a number of longitudinal bands -3- and -4-. These grooves can be formed by discontinuous cuts or by continuous grooves which do not pass completely through the strips. In any case their function, as will be seen below, is to form fold-lines towards one side or the other. Beads or lines of glue -5- will be deposited on the bands -3-. Lines or beads of glue -5- will also be deposited on one of the strips -1a-. It is important to stress that the bands -3- which have lines of glue -5- deposited on them occupy positions offset from each other, following virtual lines A and B running diagonally with respect to the group of strips -1, 1a- (FIG. 2).
On their downstream travel along the path, the strips -1, 1a- converge progressively until, at a station of general reference -6- (comprising, for example, two adjacent rollers), they are overlapped on each other and glued under pressure. From this station -6-, the strips form a glued assembly -1b- which passes through a transverse cutting station -7- to provide pieces -9-, which in the version shown (FIGS. 1 and 3) will be cut again into shorter pieces -10-, which will constitute the folded dividers.
By virtue of the position of the glued bands -3-, upon unfolding of the piece -10- a divider -11- is formed, in which the strips -1- are linked to each other through the unglued sections -4-, arranged at right angles to the glued sections -3-, with the special feature that the sections -3- of each strip -1- are folded in opposite directions along the fold-lines formed by the grooves -2-. Compartments "C" are defined between the sections -4- and the sheets -1-, to hold bottles or other articles.
It should be noted that at the ends of the strips situated on two or four sides of the divider -11-, narrow flap-like bands -3a- are defined, with those on either side of the divider arranged in coplanar manner; these can then be glued directly to the sides of an unfolded box -12-, or to sheets -1a- of the divider itself, which shall in turn be juxtaposed onto the sides of the box -12- (FIGS. 6 to 9), depending on whether the divider is fitted into the box using a mechanical or manual method, as outlined in greater detail below.
At the cutting station -7- and other stations down the line but not shown, straight cuts can be made to provide pieces -9- and -10- having straight longitudinal edges (FIGS. 1, 3 and 4), or else broken or mixed outline cuts to form recesses -13- on one of the longitudinal edges (either the upper or lower), whose outline narrows progressively from the edge in question, as illustrated in FIG. 5 of the drawings. When the divider is fitted between the bottles previously situated in a box, or when bottles are placed into the divider fitted into the box, these recesses -13- prevent the edge of the divider from striking against the edges of the bottle labels and causing them to come away.
As can be deduced from all that has been described and from observation of the drawing, the above method allows fully finished dividers to be obtained in a continuous process, at a much higher production rate than with any of the known manufacturing methods and, therefore, at lower cost.
With this procedure the dividers are obtained from continuous laminar cardboard strips, of lower cost than the ridged cardboard sheets which have been used to manufacture known dividers.
The divider, furthermore, independently of the manufacturing method used, has several advantages with respect to known versions. In the first place, it can be incorporated into a box using a mechanized process: in this case the divider would be one like that shown in FIG. 6 of the drawings, with the flaps -3a- glued onto the sides of the box. It is also possible to obtain a divider with sheets -1a- (FIGS. 7 and 8), for manual placement inside the box -12-. In this case, at least one of the ends -1c- of the sheets - 1a- rests on the sides of the box -12- to prevent it being folded accidentally. Between the end -1c- and the immediately adjacent section -4- there is a space equivalent to that existing between two parallel and immediately adjacent sections -4- of the divider, in order to form compartments "C" (FIG. 9).
It should be noted, finally, that the divider object of the invention could be obtained from precut sheets instead of from continuous strips -1-.
Independent of the object of the invention shall be the number of strips of cardboard or similar material from which the dividers are obtained, as well as their dimensions and, consequently, the number and dimensions of the sheets or strips formed by the manufactured dividers. The particular mechanisms used to carry out the different steps of the method shall also be optional.
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The source materials are supplied in continuous strips of cardboard situated initially in separated planes laterally offset from each other. Longitudinal grooves are made along the strips, dividing them into longitudinal bands. The strips are overlapped and glued under pressure to join them together. Once glued they are cut into pieces. The pieces constitute the folded dividers, made up of sections and folded and glued sections which form the union between the sections of each strip. Optionally, narrower sections are glued directly onto the sides of a box, or to sheets glued in their turn to the sides of the box. The upper edges of the divider can be straight or present recesses. The divider formed by strips glued by the sections which make up sections at right angles to the strips is folded and unfolded at the same time as the box into which it is fitted.
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This is a continuation of application Ser. No. 08/413,108, filed Mar. 29, 1995, now U.S. Pat. No. 5,584,982 which is a continuation application Ser. No. 08/072,096, filed Jun. 3, 1993, now U.S. Pat. No. 5,439,578.
FIELD OF THE INVENTION
This invention relates to apparatus used for biochemical analysis.
BACKGROUND AND SUMMARY OF THE INVENTION
Simultaneous analysis of a large number of biological samples is useful in flow cytometry, DNA sequencing, liquid chromatography, oligonucleotide analysis, zone electrophoresis of proteins, as well as other electrophoretic techniques. In particular, rapid DNA analysis is of importance in the Human Genome Project, which is an attempt to identify the sequence of bases (dideoxynucleotides) in human DNA.
One technique that has been applied to the sequencing of DNA is capillary electrophoresis. In capillary electrophoresis, an appropriate solution is polymerized or gelled to form a porous matrix in a fused silica capillary tube of internal dimensions in the order of 50 μm. An electric filed is applied across the matrix. Fragments of sample DNA injected into one end of the capillary tube migrate through the matrix under the effect of the electric field at speeds that depend on the length of the fragment. Hence, different length fragments arrive at a detection part of the capillary at different times. The dideoxynucleotide at one end of the fragment may be labelled with a fluorescent marker during a reaction step. The fluorescent marker is associated with the terminating dideoxynucleotide. When the fragment passes through a beam of light from a laser in the detection zone, the fluorescent marker fluoresces and the fluorescence may be detected as an electric signal. The intensity of the electric signal depends on the amount of fluorescent marker present in the matrix in the detection zone. The dideoxynucleotide at the end of the fragment may then be identified by a variety of methods. As different length fragments migrate through the matrix under the applied field, a profile of the fragments may be obtained.
The use of three different DNA sequencing techniques is set out in Swerdlow, H. et al, Three DNA Sequencing Methods Using Capillary Gel Electrophoresis and Laser Induced Fluorescence, Anal. Chem., 33, 2835-2841, Dec. 15, 1991, and the references cited therein. In the Tabor and Richardson technique (one spectral channel sequencing), a single fluorescent marker is used, and the amount of dideoxynucleotide in the reaction mixture is varied so that each base of the DNA fragment may be identified with a particular fluorescent peak height. For example, the concentration of dideoxynucleotides might be varied in the ratio of 8:4:2:1. The variation in fluorescence intensity with time will then identify the sequence of bases. In the DuPont system (two spectral channel sequencing), succinylfluorescein dyes are used to label four dideoxynucleotides. A single wavelength (488 nm) is used to excite fluorescence from the dyes. Emission is distributed between two spectral channels centered at 510 and 540 nm. The ratio of the fluorescent intensity in the two spectral channels is used to identify the terminating dideoxynucleotide. In the Applied Biosystems system (four spectral channel sequencing), four dyes (FAM, JOE, TAMRA and ROX) are used to label primers to be used with each dideoxynucleotide reaction. Two lines from an argon laser (514.5 and 488 nm) are used to excite fluorescence. Interference filters are used to isolate emission at 540, 560, 580 and 610 nm and peaks of the resulting four electrical signal profiles are used to identify the bases.
Application of capillary electrophoresis to DNA analysis is complicated by the scattering of light from the porous matrix and the capillary walls. For this reason, there has been proposed use of a sheath flow cuvette in which a sample stream of DNA is injected under laminar flow conditions in the center of a surrounding sheath stream, generally of the same refractive index. Such a cuvette is described in Swerdlow H., et al, Capillary Gel Electrophoresis for DNA Sequencing: Laser Induced fluorescence detection with the sheath flow cuvette, Journal of Chromatography, 516, 1990, 61-67.
However, the above described methods of DNA sequencing using capillary electrophoresis have used single capillaries and rapid DNA sequencing and other biological process requiring simultaneous analysis of sample streams require use of multiple capillary systems.
One such multiple capillary system is described in Huang et al, Capillary Array Electrophoresis Using Laser Excited Confocal Fluorescence Detection, Anal. Chem. 64, 967-972, Apr. 15, 1992. In the Huang device, multiple capillaries lying side by side in a flat array holder are sequentially scanned by a laser beam and fluorescence detected from the capillaries using a photomultiplier tube. Such a device suffers from the same difficulties as with a single capillary that is scanned with a laser, namely that there is light scatter from the capillary walls and interfaces between the matrix and capillary.
The inventors have therefore proposed a multiple capillary analyzer that allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed.
In one aspect of the invention, there is provided a multiple capillary analyzer using a modified sheath flow cuvette. A linear array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system.
In a further aspect of the invention, the retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries.
In a still further aspect of the invention, the optical system utilizes optic fibres to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands.
In a still further aspect of the invention, the array may be rectangular, including square, or the like formed of plural rows of capillaries terminating at different levels in a rectangular sheath flow cuvette. A rectangular array of lenses receives light emitted, scattered or reflected from samples emerging from the capillaries and the light is then converted to electrical signals and processed.
BRIEF DESCRIPTION OF THE DRAWINGS
There will now be described a preferred embodiment of the invention, with reference to the drawings, by way of illustration, in which like numerals denote like elements and in which:
FIG. 1 is an isometric schematic view of an exemplary biochemical analyzer according to the invention showing a sheath flow cuvette, multiple capillaries, a flow chamber and optical system;
FIG. 2 is a section through the analyzer of FIG. 1 without optical components;
FIG. 3A is a section through the chamber of FIG. 1 showing the passage of a laser beam through the chamber;
FIG. 3B is a schematic showing a light collection and detection system for used with the analyzer of FIG. 2;
FIG. 4 is a section through the multicapillary sheath flow cuvette of FIG. 2 (the section is through the center but also shows pedestals, which are off center, and appear behind the chamber);
FIG. 5 is a section at right angles to the section of FIG. 4 (the section is through the center but also shows pedestals, which are off center, and appear behind the chamber);
FIG. 6 is a section along the line 6--6 in FIG. 5 showing the inlet for sheath fluid;
FIG. 7 is a section along the line 7--7 in FIG. 5 showing the off center pedestals that retain the flow chamber;
FIG. 8 is a section along the line 8--8 in FIG. 4 showing the base of the cuvette;
FIG. 9 is a section along the line 9--9 in FIG. 4 showing a split rod with a slot along its central axis for retaining the capillary tubes;
FIG. 10A is section through the top of the sheath flow cuvette;
FIG. 10B is longitudinal section through the sheath flow cuvette;
FIG. 10C is a section through the bottom of the sheath flow cuvette;
FIGS. 11A, 11B and 11C are graphs showing the results of DNA sequencing using apparatus according to the invention;
FIG. 12 shows a schematic of a further method of detecting analyte;
FIG. 13 shows an apparatus for use for the electrochemical detection of analyte;
FIG. 14 is a schematic section of an analyzer having a rectangular (in this case square) array in a square flow chamber;
FIG. 15 is a schematic view from the bottom of the chamber of FIG. 14; and
FIG. 16 is an isometric view of a square grid of capillaries for insertion in the chamber of FIG. 14.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown an analyzer for analyzing a sample of DNA including a sheath flow cuvette 12 enclosing the ends of five capillary tubes 14 arrayed side by side in a line like the teeth of a comb. The capillary tubes 14 are held in a header 16 with their cleaved ends 18 terminating inside the chamber 12. The other ends 20 of the capillary tubes 14 terminate in five of the wells 22 of a conventional microtiter plate 24. The capillary tubes 14 are conventional fused silica capillaries, with about 50 μm ID and 150 μm OD, available from Polymicro. The cuvette 12 is formed of a quartz chamber 26 secured within a stainless steel holder 28, the design of which is shown in FIGS. 4-9 in more detail. A high voltage source 30, such as a Spellman RHR-30PN60 30 KV power supply, is connected to the stainless steel holder 28 through a first electrode 32 (grounded) and also through five second electrodes 34 to fluid in the wells 22. Thus, when the capillary tubes 14 and chamber 12 are filled with conducting material, a high voltage may be applied across the material in the capillary tubes using the high voltage source 30. The circuit is formed by the grounded electrode 32, the stainless steel holder 28 (formed of cap 68, capillary retainer 64, chamber retainer 66 and cap 70), fluid in the cuvette 12 and in the chamber 26, matrix in the capillary tubes, including sample buffer if present, buffer solution in the wells 22 and the electrodes 34.
A laser 36 or other source of collimated electromagnetic radiation provides a collimated beam 38 of light that is aligned to pass through a focusing lens 40 into the chamber 12 along a projection of the capillary tubes into the chamber, as close as possible to the ends of the capillary tubes 14, as shown in FIG. 3A. The wavelength of the laser 36 is chosen to excite fluorescence in the sample being analyzed, as for example DNA reacted with a fluorophor. An appropriate choice for DNA analysis is an Innova 70-4 argon ion laser available from Coherent Inc. of Palo Alto, Calif. Such a laser may be operated with multiple wavelength mirrors (488 and 514.5 nm), with appropriate selection of the wavelength depending on the method used for sequencing the DNA.
Fluorescence from the sample in the chamber 12 is detected through a collection lens 42 that images the fluorescence on to a plurality of 1 mm aperture GRIN (gradient index) lenses 44 (available from Nipon Scientific Glass through Precision Cells, Inc. of Farmingdale, N.Y.) which are affixed to receiving ends 46 of fiber optics 48. The fibre optics 48 may be secured in known manner as for example to a Melles Griot optical bread board (not shown). Transmitting ends 50 of the fiber optics 48 lead into avalanche photodiodes 52 or other individual photon detectors, one for each capillary tube 14, and whose output is connected through an interface 54 to a computer 56. Exemplary photodiodes 48 are RCA (EG&G) C30902S photodiodes powered by a PS310 Stanford Research System high voltage power supply or model SPCM 100 photodiodes available from EG&G Canada Ltd. Fluorescence is transmitted along the fiber optics 48 to the photodiodes 52 whose electrical output is proportional to the intensity of the fluorescence. Electrical signals output from the photodiodes 52 are passed through a data acquisition board 54 (such as may be obtained from National Instruments or from Data Translation, model DT2221-G) to a computer 56 such as a Macintosh II computer for processing according to known techniques. Such processing includes filtering the signal to give a desired frequency response, and a second filter or phase lock loop to identify the position of the peak centers. For interface boards from National instruments, it may be necessary to decrease illumination intensity to avoid over saturation of the photon detectors. Alternatively, light collected in individual GRIN lenses 44 may be passed through a bundle of optical fibres and imaged onto or abutted against an array detector. However, CCD cameras are not believed to be fast enough for high speed DNA sequencing.
As shown in FIGS. 3A and 3B, if the fluorescence emitted from the DNA sample has a spectrum centered on more than one wavelength of light, then a means of dividing the spectrum of the received light may be used. Light from laser 36 passes through focusing optic 40 and passes through the sample streams 58. Fluorescence from the sample streams is collected by optic 42 and passed through a spectral filter 60 (for filtering scattered light) to GRIN lenses 44 on the ends of fibre optics 48. Light in the fibre optics 48 is passed through wavelength division demultiplexers 62 where light from different spectral bands is separated into two sets 48a and 48b of fibre optics and two sets of avalanche photodiodes 52a and 52b.
The selection of the filter 60 and the optical system depends on the sequencing reaction to be performed. For a single codor sequencer, using the sequencing method of Richardson-Tabor, a single spectral filter 60 with a bandwidth of 45 nm centered at 530 nm may be used to detect fluorescein labeled products. The filter should be selected to minimize background signals due to Raman and Raleigh scatter of the excitation beam 38. For the DuPont sequencing system, two detection channels are required, one detector channel to image light in a band centered at 510 nm and the other to image light centered at 540 nm. Light collected from the collection optic is split into two paths using the wavelength division demultiplexers 62, one path leading to one set of photon detectors 52a and the other leading to the other set of photon detectors 52b. Other methods of wavelength division demultiplexing may be used as for example rapidly switching a filter wheel so that the light from the sample stream is time division demultiplexed. For sequencing using the method developed by Applied Biosystems Inc. (see the Swerdlow article), four channels are required. As with the-DuPont system, two detector systems are used, and a filter wheel may be used as the spectral filter 60 to rotate two selected filters across the path of the light collected by the collection optic. By alternating the two filters in the two detection systems, a signal from four spectral channels may be generated.
The collection optic 42 should be selected to provide an image that is matched in size to the aperture of the GRIN lenses 44, such as may be provided by a flat field high numerical aperture microscope objective, for example as made by Leitz/Wild (0.40 NA achromat objective). With a sample stream diameter of 50 μm and a GRIN lens diameter of 1 mm, for example, the magnification should be about 20×, generating spots several millimeters apart. Since the light from the collection optic tends to expand with a curved wavefront, the GRIN lenses should be arranged to have their collection faces perpendicular to radii of the wavefront.
Referring to FIGS. 4-9, the chamber 26 is held in a stainless steel holder 28 to form a sheath flow cuvette. The holder 28 includes an upper section or capillary retainer 64 and a lower section or chamber retainer 66 each machined from individual pieces of steel rod. The retainers 64 and 66 are threaded together at 65 (threads not shown). A top cap 68 is threaded onto the upper end of retainer 64. A bottom cap 70 is threaded onto the lower end of retainer 66. An upper seal 72 made of plastic forms a seal between the cap 68 and retainer 64. A like seal (not shown) may be used to seal the cap 70 to the retainer 66. An O-ring (not shown) or other suitable seal should be provided to ensure that the retainers 64, 66 are sealed together to prevent leakage at 65. The cap 68 has a central hole for receiving the capillary tubes 14. A plastic sleeve 74 into which the capillaries are threaded has epoxy applied to it to form a seal around the capillary tubes 14 as they enter the cap 68. The capillary retainer 64 includes a hollow bore lined with a plastic cylindrical and annular spacer 76. Filling out the hollow bore of the retainer 64 are two facing semi-circular metal rods 78 each with a groove machined into their facing flat faces to form a rectangular slot 80. The slot 80 is dimensioned to receive the capillaries 14 snugly and hold them against each other in a line.
The chamber retainer 66 includes two circular sections 82 and 84 and a pedestal section 86 in which the metal of the rod has been machined away to form four pedestals 88 in which the chamber 26 is securely retained. Metal in the chamber retainer 66 is machined away in the pedestal section 86 to form cavities 89. Removal of the metal in this section 86 allows a microscope objective to be placed close to the chamber 26 (within a few millimeters). Upper circular section 82 includes a sheath fluid inlet 90 and a bubble removal port 92. The sheath fluid inlet 90 is connected via Teflon™ tubing 94 (see FIG. 2) to a source of sheath fluid 96 (not shown to scale). The bubble removal port 92 is connected by Teflon™ tubing 98 to a valve 100. The tubing 94 may include a three way valve 102 with waste line 104 for removing bubbles from the sheath fluid. In the chamber retainer 66, at the base of the chamber 26 is a plastic bottom plug 106 that holds the chamber 26 in place. The cap 70 is provided with a waste outlet port 108 that is connected to Teflon™ tubing 110 to a waste beaker 112.
As shown in FIG. 2, sheath fluid is provided through inlet 90. The sheath fluid enters the top of the chamber 26 and moves as a syphon flow under gravity from the top of the chamber to the bottom, past the ends 18 of the capillary tubes 14. The fluid should be provided in a steady, non-pulsed flow, and should be filtered and purified to avoid any background signal passing due to particles passing through field of view of the collection optics. The fluid is chosen to have similar index of refraction as the fluid carrying the sample DNA to avoid reflection and refraction at interfaces between fluids of different indexes of refraction. The simplest way to achieve this is to use the same fluid for the sheath fluid as carries the sample DNA, as for example 1×TBE. The volumetric flow of the sheath stream is low, in the order of less than 10 mL/hr, which for the embodiment described is in the order of 4 mm/s, though it may be as much as 10× less for some applications. The fluid is drained to waste after exiting the chamber 12 through port 108. The waste beaker 112 should be kept half-filled with buffer. If the waste stream forms drops, the sample stream profile is distorted when the drop detaches. A periodic noise results from the periodic detachment of the drops. The beaker 112 preferably has a small hole drilled in it with a tube leading to a larger beaker 114. The level of the first beaker 112 remains constant, so that the sheath flow velocity under conditions of syphon flow changes slowly. A constant syphon head may also assist in ensuring constant sheath flow rate. For the apparatus described a 5 cm syphon head has been found adequate. Bubbles should not be present in the sheath flow. These can be eliminated by visual inspection and eliminated using the three way valve 102 (by switching the fluid containing the bubble to waste).
Referring to FIGS. 10a, 10b and 10c, the chamber 26 includes end walls 122a, 122b, side walls 124a, 124b top 126 and bottom 128. The walls need not be planar but may contain projections to align the capillaries. Each wall is 1 mm thick at the top and made of high quality optical quartz, or such other inert material as is transparent to the selected electromagnetic radiation emitted by either the laser 36 or the sample passing out of the capillary tubes 14. The side walls 124a, 124b are constant thickness from top to bottom, while the end walls each thicken inward towards the bottom by 50 μm. The interior of 130 of the chamber 26 has the same dimension X laterally as the thickness of the capillary tube used (150 μm in the exemplary embodiment) and the dimension Y 1 from end wall to end wall a little more (50 μm more in the exemplary embodiment) than the sum of the thicknesses of the capillary tubes 14. The interior 132 at the bottom of the chamber has the same dimension X laterally as the thickness of the capillaries used and the dimension Y 2 from end wall to end wall a little less (50 μm in the exemplary embodiment) than the sum of the thicknesses of the capillary tubes 14. The capillary tubes 14 should be snugly fit in the interior of the chamber 26, with their ends terminating adjacent each other. It is preferable that the capillary tubes 14 be placed in the chamber 26 before they are filled with matrix material.
Particularly if capillary tubes are re-used, the collection optics, including the GRIN lenses 44, will be fixed and the capillary tubes 14 must be aligned with the collection optic so that fluorescence from the sample stream irradiated by the laser beam 38 is imaged onto the GRIN lenses 44. The capillary tubes 14 are first inserted through the cap 68 and retainer 64 into the slot 80 formed by the two rods 78. The capillary tubes 14 may be loaded together or one by one. The capillary tubes 14 are inserted into the chamber 26 in this manner and pushed together into the chamber 26 until they are firmly held in the chamber 26. With the chamber 26 of the dimensions stated, the capillary tubes 14 will terminate about half way through the chamber 26. The top of the chamber 26 thus encompasses the capillary tubes 14 with the capillary tubes 14 abutting the interior walls of the chamber at the ends near the center of the chamber and at the sides throughout the length of the capillary tubes within the chamber 26. Abutment of the capillary tubes against the interior walls of the chamber seals any gaps between the capillary tubes at the center of the chamber 26. Unless such gaps are sealed, non-uniformities in the sheath flow can result which can affect the signal quality. The capillary tubes 14 are preferably cleaved at their ends using well known techniques employed in the manufacture of fiber optics in order to obtain a smooth and flat end. The capillary tubes 14 will therefore extend into the interior of the chamber 26 an amount that is dependent on the rate of decrease of the end wall to end wall dimension of the chamber, and will typically be 1 cm for the exemplary embodiment described. The chamber 26 has height H about 2 cm from top to bottom as shown in the example. Such chambers may be purchased from Nipon Scientific Glass through Precision Cells, Inc. of Farmingdale, N.Y., to order. The height H of the chamber is somewhat arbitrary, sufficient to allow both fixture of the capillary tubes and to allow the light beam to pass through the chamber below the capillary ends. 2 cm is chosen to allow addition of a second laser beam below the first if two lasers are used for analysis. The top of the side walls 124a, 124b should be slightly bevelled to ease insertion of the capillary tubes 14. The construction of the chamber is quite important, particularly when the capillary tubes are not electrically isolated from the high voltage applied across the porous matrix material in the capillary tubes. If the capillary tubes are not isolated electrically, repulsive forces between them can create forces which if not evenly distributed, can shatter the capillary tubes. The capillary tubes 14 should therefore all be held securely in the chamber to prevent these stresses from concentrating at one tube.
The capillary tubes 14 should terminate within about 10 μm from each other. The laser beam 38 should entirely pass within about 100 μm from the ends of the capillary tubes. Careful alignment of the capillary tubes is required so that the image of the fluorescence falls directly on the GRIN lenses. This can be checked by passing light backward through the GRIN lenses. The light should pass through the sample stream exactly at the same point that fluorescence due to the laser beam occurs. Visual inspection can be used to verify the correct alignment of the capillary tubes, with appropriate safety precautions due to the use of laser light.
The length of the flow cell (distance between the end walls 124a and 124b) and the number of capillaries that can be detected in a single flow cell are determined by the distance over which laser beam size can be matched to the sample stream radius as it exits the capillary. To optimize sensitivity, the laser beam should be located as near as possible to the ends of the capillaries to minimize effects of diffusion of the sample into the sheath fluid. The laser beam should therefore pass through the acceleration region of the sample flow. At this point, faster moving sheath fluid draws the sample fluid from the matrix. Since the entire cuvette is grounded (through electrode 32), there is .very little electric field inside the cuvette, and the sample fluid is not drawn by the electric field out of the capillaries. Thus it is the sheath flow that draws the sample fluid from the matrix in the capillaries. As the sample fluid moves away from the end of the capillary its cross-section contracts, and then expands due to diffusion of the sample fluid into the sheath fluid. The laser beam should pass through a point above the point of maximum contraction, thus before the diffusion zone.
A single laser beam is aligned to be parallel with the long axis of the cuvette (end wall 122a to end wall 122b) simultaneously exciting fluorescence from each sample stream in turn. The size of the laser beam should be selected to ensure similar illumination of each sample stream. With a lens (for example a microscope objective with 1× magnification) between the laser 36 and the chamber 26 a beam waist can be located in the center of the chamber. The beam spot size at the center of the chamber should be equal to the sample stream diameter at that point. With 50 μm ID capillary tubes, this is about 50 μm. The beam diameter will be larger in both directions away from this point, but with this arrangement, the fluorescence is close to optimum.
For setting up the analyzer for DNA analysis, care must be taken as is known for capillary electrophoresis. Thus, the matrix material must be selected for stability, for discrimination of longer base lengths and for speed of sequencing. No one matrix is suitable for all applications. For DNA sequencing, a 0% C (non-cross-linked), 5-6% T acrylamide gel has found to be adequate and has the added advantage of low viscosity which allows it to be readily replaced, without removal of the capillary tubes 14 from the chamber 26. A proprietary gel, Long-Ranger™ from AT Biochemicals, has been found useful for applications using high voltage in the order of 800 V/cm, such as in diagnostic applications. Long-Ranger™ gel allows sequencing rates in the order of 200 bases in 3 minutes with greater than 95% accuracy. 0% C gels provide sequencing rates in the order of 600 bases in two hours at 200 V/cm. Gel temperatures between 20° C. and 35° C. have been found to give good results.
The Long-Ranger gel is prepared within a 50 μm ID capillary by polymerization of a carefully degassed 5% solution of Long-Ranger in a 7M urea, 0.6×TBE buffer. Polymerization is initiated with 0.4 parts per thousand (V/V) TEMED and 0.4 parts per thousand (W/V) ammonium persulphate. Such a gel is stable and may be used for three separations. Use of Long-Ranger gel with a single 50 μm ID capillary has yielded sequencing rates of 3200 bases per hour at 800 v/cm.
The gel may include 0-20% of formamide. Addition of formamide in this range decreases compressions, particularly in the range 10-20%, thereby increasing resolution in regions of compression. However, it has been found that too much (20% or more) formamide reduces the separation rate, theoretical plate count, and resolution for normally migrating fragments without a concomitant decrease in compressions. An optimum concentration of 10% formamide improves resolution of compressed regions without degrading other characteristics of the gel. It has also been found that operating the gel at room temperature is adequate and simplifies the engineering of the analyzer. Results of using formamide have been described in Rocheleau, M. J., et al, Electrophoresis, 13, 484-486, 1992.
The gel should be established in the capillary tubes 14 without voids or bubbles forming during polymerization of the acrylamide due to shrinkage, which may be particularly acute if a bifunctional silane reagent is used to bind the gel to the capillary wall. Such bubbles can be eliminated by use of low percent acrylamide, short columns, adding polyethylene glycol to the monomer mixture (though this is not desired for DNA fragments longer than about 100 bases since it degrades the separation) or by allowing polymerization to occur in a pressured vessel or other methods known in the art.
Also, defects in the gel at the ends 20 may occur when loading samples of DNA into the capillary tubes 14. Such defects are particularly of concern when the capillary tubes 14 are reused. It is therefore desirable to cut off a portion (several millimeters) of the capillary tube 14 after a run. Also, such a defect can be minimized by loading smaller amounts of DNA sample, as much as five times lower, as compared with conventional electrophoresis sequencing of DNA. Thus for example the sample using the apparatus disclosed should be loaded at 150 V/cm for 60 s.
Flaws in the gel can be inspected by visual inspection in a microscope or by passing two laser light beams at an angle through the gel to intersect each other in the gel. Modulated light scatter of the laser light from flaws in the gel may be detected using a collection optic and photomultiplier tube.
Loading of the gel into the capillary tubes 14 also requires care. It is desirable that gel characteristics be uniform from capillary tube to capillary tube. If the capillary tubes are loaded with gel sequentially, differences in the gel may severely degrade the analysis. It is preferable to load the gel monomer into a single container and to fill the capillaries with the gel from the single container simultaneously, as by vacuum syphoning the gel. At high electric fields (in the order of 800 V/cm), the gel can extrude about 50 μm from the detection end of the capillary. To eliminate extrusion, about 2 cm of the gel at the detection end is covalently bonded to the interior walls of the capillary tubes with γ-methacryloxypropyltrimethoxysilance. Such known methods for establishing a gel as described in U.S. Pat. Nos. 4,865,706 and 4,865,707 to Karger et al and 4,810,456 to Bente et al may also be used.
Data has been collected from the system of FIG. 1 with detection at three capillaries using the Tabor and Richardson sequencing technique. An M13mp18 template was used to generate fragments of DNA. Manganese was used instead of magnesium in the sequencing buffer. Sequenase was used for chain extension. A FAM labeled primer is used and a single sequencing reaction is performed with ddATP, ddCTP, ddGTP and ddTTP present in a 8:4:2:1 ratio. A 50 μm capillary was filled with 4% T, 5% C gel and operated at 200 V/cm. For a run of 330 bases in 70 minutes, comparable data was obtained as for single capillary systems, although the throughput was 850 bases/hour for a 3 capillary system. FIGS. 11a, 11b and 11c show the results of the sequencing.
Resolution is limited to fragments less than 300 bases in length at high voltages near 800 V/cm. Generally speaking, retention time increases linearly with fragment length for a given high V/cm until the mobility of the fragments approaches a limiting value and no separation is achieved. This is called biased reptation. As the electric field increases, the transition to biased reptation moves to shorter fragments. Biased reptation is highly undesirable since it causes sequencing fragments to coelute, destroying the separation resolution. Hence for longer fragments (in the order of 600 bases), the electric field can be decreased to about 140 V/cm, with an increase in separation time. Moderate gel temperature (in the order of 20° to 35° C.) can assist in improving sequencing rate, though it does not appear to strongly affect the transition from reptation to biased reptation. Lower % T acrylamide gels can also assist in the sequencing of longer fragments.
The analyzer described here has utility for a wide variety of applications, with some modifications. In each case there is some means to force analyte through the capillaries, the capillaries are held in the chamber as shown in FIGS. 1 and 2 for example, and sheath fluid is supplied through the cuvette, with the sheath fluid preferably having the same index of refraction as the fluid carrying the analyte.
The detection of analyte may also be accomplished using thermooptical absorption. In this technique, the laser 36 is used to excite the analyte which tends to heat the analyte and change the index of refraction of the fluid by which it is carried. As shown in FIG. 12, the deflection of the beams 138 from a second laser 136 after collimating with an appropriate optic 137 by the sample fluid emerging from the ends of the capillary tubes 14 is then detected by the optical system 140, which may be designed as shown in FIG. 1.
An analyzer for use as an electrochemical detector is shown in FIG. 13. Electrodes 142 enter the chamber 26 (made of an inert non-conducting material such as quartz) from the bottom end 132 of the chamber. Each electrode 142 is connected to an amplifier (not shown), and the output of the amplifier is provided to a processor, for example a computer, through an interface for analysis in accordance with known principles (similar to the optical processing of the signals). In such a case, the laser 36 is not required, since the identification of the sample is by electrochemical analysis. Multiple capillaries allow for rapid analysis.
The analyzer may also be used to detect impurities in fluids by detecting light scatter. In such a case, the high voltage source 30 is not required, since the fluid may be pumped directly as a fluid through the capillary tubes, nor is the spectral filter 60 required since the total intensity of the scattered light may be detected. The GRIN lenses 44 and detectors 52 detect variations in the scatter of light resulting from particles or impurities in the fluid.
The analyzer is also useful for the detection of organic contaminants, for example the fluorescent detection of polycyclic aromatic hydrocarbons. In such detection, the capillary tubes are filled with chromatographic packing material (coated silica beads) instead of a polymer and the analyte sample is forced through the capillary tubes using a pump instead of the high voltage source 30. The laser 36 should emit radiation at about 330 nm or such other appropriate wavelength for detection of organic contaminants. Fluorescence emitted by the sample of contaminant is detected through an appropriate spectral filter 60 and the optical apparatus shown for example in FIG. 1.
In a further example, the analyzer may be used for flow cytometry. In flow cytometry a sample containing cells taken from an animal or human body by fine needle aspiration is stained using a fluorescent reagent such as a nucleic acid stain or antibodies. With the present analyzer, the sample is forced under air pressure by a pump that replaces the high voltage source 30 through the capillary tubes 26 and the laser beam 38 is passed through the sample as it emerges from the capillary tubes 26 into the sheath flow. The intensity of the fluorescence from the fluorescent reagent is detected using the optical system of FIG. 1 and used to estimate the number of sets of chromosomes in the cells, and this is useful, in accordance with known procedures in the diagnosis and prognosis of cancer.
Multiple capillary tubes may also be used to spray analyte into a mass spectrometer. In such a case, the capillaries are bundled within a circular or polyhedral cuvette with sheath flow about the capillaries. The bundle of capillaries is inserted into the ionization chamber of a mass spectrometer such as the triple quadrupole mass spectrometer sold by Sciex Division of MDS Health Group Limited, of Thornhill, Ontario, Canada, under its trademark TAGA 6000E. For electrospray of analyte, the capillary tubes are made conducting at the end that extends into the ionization chamber. Electrical potential is applied to the ends of the capillaries in known manner.
A square, rectangular or other suitable polyhedral array of capillary tubes may also be used as well, as shown in FIGS. 14, 15 and 16 for the case of a square capillary array. The array may be rectangular as well. Other polyhedral arrays could be used in principal, but this complicates the optics. The array of capillary tubes 14 is formed from five rows 144 of five capillary tubes 14 each, all bound within a square chamber 146 forming part of a square sheath flow cuvette. The cuvette is similar to the cuvette shown in FIGS. 4-9 only the central chamber is square. An optical system 148 disposed adjacent the cuvette includes a collection optic 154, GRIN lenses 156, and optic fibres 158 leading to photodiodes and the balance of the optical system as shown in FIG. 1.
Each row 144 of capillary tubes is similar to the row shown in FIG. 1, but succeeding rows in the direction of the optical system 148 terminate higher in the sheath flow cuvette as shown at 160. All capillary tubes 14 in a row terminate adjacent each other. Sheath flow is provided about all of the tubes 14 within the sheath flow cuvette. All four walls 150 of the sheath flow cuvette taper inward towards the bottom 152 of the chamber. The ends of the capillary tubes 14 define a sloping plane P, sloping downward and away from the optical system 148. An elliptical or other linear cross-section laser beam 162 oriented at the same slope as the sloping plane (or close to it) is directed just below the ends of the capillary tubes 14. Fluorescence of the samples forms a sloping square array of fluorescent spots 164 that appears as a square grid of spots 166 from a view at right angles to the cuvette.
Fluorescence from sample streams emerging from the capillary tubes 14 is collected by an optic 154 and imaged on to the square array of GRIN lenses 156, which lie in the image plane of the fluorescent spots produced by the optic 154. The GRIN lenses 156 are oriented with their faces perpendicular to the wavefront from the collection optic 154. Light collected by the GRIN lenses is transmitted through optic fibres to photodetectors of the type shown in FIG. 1.
It is possible to operate the cuvette upside down to allow bubbles in the sheath stream to move upward with the stream to waste.
A person skilled in the art could make immaterial modifications to the invention described and claimed in this patent document without departing from the essence of the invention.
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A multiple capillary analyzer allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed, using a modified sheath flow cuvette. A linear or rectangular array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system. The retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries. The optical system utilizes optic fibres to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands.
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TECHNICAL FIELD
[0001] The present invention relates to an incident/potential-incident factor area specifying apparatus and an incident/potential-incident factor area specifying method of specifying an incident/potential-incident factor area as an area to be noticed by the driver of a vehicle in order to prevent an incident and a potential-incident.
BACKGROUND ART
[0002] Incident prediction information and incident statistic/analysis information are useful to prevent a vehicle incident. Such information is provided to, for example, the driver of a vehicle, a road administrator who performs safety design of a road and examines an improvement plan, a police officer who makes an inspection of a traffic incident and a traffic safety campaign, an incident appraiser and an insurer conducting an incident analysis, and the like.
[0003] It is said that about 40 percent of traffic incidents occur due to delay in perception or a mistake in judgment on a danger without avoidance behavior. With respect to following driving in a single road, various safety driving support techniques to address inattention to the front of drivers are developed.
[0004] For example, an active safety system mounted on a car is one of such techniques. The system measures the distance to a driving vehicle or a pedestrian in front by using a millimeter-wave radar or a laser radar. The system always monitors whether safe distance is maintained according to drive speed or not on the basis of the measured distance and, when the vehicle comes too close, gives warning to the driver.
[0005] At an intersection where traffic is heavy, a driver has to disperse visual attention in a wide range. Consequently, a system which monitors only the front as described above cannot sufficiently support safety driving. Many of traffic incidents occur in intersections. For example, about 60% (about 70% in big cities) of traffic incidents in Japan occur in and around intersections. Therefore, also on driving in intersections, a technique for supporting safety driving is demanded.
[0006] For example, Patent Literature 1 discloses a dangerous place display system which estimates the courses of vehicles and displays an area predicted to be crossed by the courses as a dangerous area so as to be overlapped on map data.
[0007] For example, Patent Literature 2 discloses a notifying system, when an oncoming vehicle located in a blind spot of a vehicle which turns right in an intersection is present, of notifying the driver on the vehicle turning right of the presence of the oncoming vehicle.
[0008] In the conventional techniques, an area (hereinbelow, called “incident/potential-incident factor area” or simply “factor area”) having high possibility of an incident or a state (hereinbelow, called “potential incident”) very close to an incident in an intersection is specified and presented. That is, the conventional techniques can support safety driving in intersections. In the case where an incident or a potential incident occurs in reality, the conventional techniques can support a subsequent work of finding the cause by the police or the like using a record of the position and time of occurrence of a blind spot.
CITATION LIST
Patent Literature
PTL 1
[0009] Japanese Patent Application Laid-Open NO. 2005-165555
PTL 2
[0010] Japanese Patent Application Laid-Open NO. 2008-41058
Non-Patent Literature
NPL 1
[0011] Society of Osaka traffic Science “Traffic Safety Science—Theory and Practice of Novel Traffic Safety, Chapter 2, Attention and Safety at the time of Driving”, Company Development Center Traffic Issue Laboratory, February 2000, p. 231-241
NPL 2
[0012] Kishiro Sawa, “Traffic Safety Overview (Revised Edition), Chapter 2: Speed and Human Physical Limit, Section 5: Speed and Limit of Visibility”, Seizando-Shoten Publishing Co., Ltd., January,2002, p. 60-65
NPL 3
[0013] Kazuma Ishimatu and Toshiaki Miura “Influence of Aging on Effective Visual Field (Mainly on Traffic Safety), Chapter 2: Effective Visual Field”, Proceedings of Human Science Department of Osaka University Graduate School, Vol. 28, March 2002, p. 17 18
SUMMARY OF INVENTION
Technical Problem
[0014] The conventional techniques, however, present even an area to which most of drivers originally pay attention and in which an incident or a potential incident does not actually occur and therefore have a problem that the presentation makes information users such as the drivers feel bothersome. When an area is presented regardless of the degree of necessity of presentation, attention of the driver to an incident/potential-incident factor area decreases and the cause becomes complicated, so that a cause investigating work becomes more complicated. Therefore, it is desirable to specify an area which is likely to be a factor of an incident or potential incident, that is, an incident/potential-incident factor area which has to be presented.
[0015] An object of the present invention is to provide an incident/potential-incident factor area specifying apparatus and an incident/potential-incident factor area specifying method capable of specifying an incident/potential-incident factor area having great need for presentation.
Solution to Problem
[0016] According to the present invention, an incident/potential-incident factor area specifying apparatus that specifies one or more incident/potential-incident factor areas to be noticed by a driver of a vehicle in order to prevent an incident and a potential incident, includes: a viewing area specifying section that specifies a viewing area of the driver of the vehicle just before occurrence of an incident or a potential incident that has occurred with the vehicle; and an unnoticed area specifying section that, if an object of the incident or the potential incident is located in the viewing area, sets an area corresponding to a location of the object, as an unnoticed area that is one of the incident/potential-incident factor areas.
[0017] According to the present invention, an incident/potential-incident factor area specifying method of specifying one or more incident/potential-incident factor area to be noticed by a driver of a vehicle in order to prevent an incident and a potential-incident, includes: a step of specifying a viewing area of the driver of the vehicle just before occurrence of an incident or a potential incident that has occurred with the vehicle; and a step, if an object of the potential incident is located in the viewing area, of setting an area corresponding to a location of the object, as an unnoticed area that is one of the incident/potential-incident factor areas.
Advantageous Effects of Invention
[0018] According to the present invention, it is possible to specify an incident/potential-incident factor area having need of presentation.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a block diagram illustrating an example of the configuration of an incident/potential-incident factor area specifying apparatus according to Embodiment 1 of the present invention;
[0020] FIG. 2 is a first schematic view for explaining a viewing area and an unnoticed area in Embodiment 1;
[0021] FIG. 3 is a second schematic view for explaining a viewing area and an unnoticed area in Embodiment 1;
[0022] FIG. 4 is a flowchart showing an example of operations of the incident/potential-incident factor area specifying, apparatus according to Embodiment 1;
[0023] FIG. 5 is a flowchart showing an example of incident/potential-incident determining process in Embodiment 1;
[0024] FIG. 6 is a flowchart showing an example, of unnoticed area specifying process in Embodiment 1;
[0025] FIG. 7 is a block diagram illustrating an example of the configuration of an incident/potential-incident factor area specifying apparatus according to Embodiment 2 of the present invention;
[0026] FIG. 8 is a first schematic view for explaining an over-noticed area in Embodiment 2;
[0027] FIG. 9 is a second schematic view for explaining an over-noticed area in Embodiment 2;
[0028] FIG. 10 is a flowchart showing an example of operations of the incident/potential-incident factor area specifying apparatus according to Embodiment 2;
[0029] FIG. 11 is a flowchart showing an example of over-noticed area specifying process in Embodiment 2;
[0030] FIG. 12 is a block diagram illustrating an example of the configuration of an incident/potential-incident factor area specifying apparatus according to Embodiment 3 of the present invention;
[0031] FIG. 13 is a first schematic view for explaining a factor blind area in Embodiment 3;
[0032] FIG. 14 is a second schematic view for explaining a factor blind area in Embodiment 3;
[0033] FIG. 15 is a flowchart showing an example of operations of a factor area specifying apparatus according to Embodiment 3; and
[0034] FIG. 16 is a flowchart showing an example of factor blind area specifying process in Embodiment 3.
DESCRIPTION OF EMBODIMENTS
[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
[0036] FIG. 1 is a block diagram illustrating an example of the configuration of an incident/potential-incident factor area specifying apparatus according to Embodiment 1 of the present invention.
[0037] In FIG. 1 , incident/potential-incident factor area specifying apparatus 100 has time-series data storing section 110 , incident/potential-incident determining section 120 , intersection data storing section 130 , map data storing section 140 , factor area specifying section 150 , and factor area presenting section 160 .
[0038] Time-series data storing section 110 stores time-series data as record of driving situations of a plurality of vehicles. The driving situation includes at least, for example, the position and orientation (or velocity vector) of each vehicle since the vehicle enters an intersection until it goes out from the intersection in a predetermined period (past one year or the like). That is, from the time-series data, the speed, acceleration, and course of each vehicle which enters an intersection can be specified at each time. The time-series data is obtained by analyzing, for example, information of a drive recorder provided in a vehicle, information collected from a smart number plate of a driving vehicle at an intersection, and the like. It is assumed that the time-series data is preliminarily stored in time-series data storing section 110 .
[0039] Incident/potential-incident determining section 120 determines whether or not an incident or potential incident occurs in any of the vehicles on the basis of the time-series data stored in time-series data storing section 110 . Incident/potential-incident determining section 120 specifies the place of occurrence of an incident or potential incident, occurrence time, and an object of the incident or potential incident. The object of the incident or potential incident refers to, basically, any or any combination of a vehicle, a motorcycle, a bicycle, or a pedestrian as the other side, i.e., the cause of the incident or potential incident of the vehicle. In some cases, the object of the incident or potential incident refers to a falling object, a construction area a curbstone, a signboard, or the like.
[0040] In the present embodiment, to simplify explanation, only a vehicle is handled as an object of an incident or potential incident. A vehicle as a reference for specifying a factor region will be called a “first vehicle”, and another vehicle as the other side of an incident or potential incident which may occur with the first vehicle will be called a “second vehicle”. Among the second vehicles, a vehicle as the other side of an incident or potential incident which actually occurs with the first vehicle is called an “object of an incident or potential incident”.
[0041] Intersection data storing section 130 stores intersection data of each of intersections. The intersection data is information of a geometric shape of an intersection, incidental facilities, the positions and sizes of buildings in the periphery, and the like, i.e., information describing the structure of the intersection. It is assumed that the intersection data is, for example, obtained from an information server via the Internet and is pre-stored in intersection data storing section 130 .
[0042] Map data storing section 140 , stores map data of each intersection. It is assumed that the map data is obtained from, for example, an information server via the Internet and is pre-stored in map data storing section 140 .
[0043] Factor area specifying section 150 specifies a factor area having high possibility as a factor of occurrence of a potential incident which occurs in the first vehicle and having great need of presentation (hereinbelow, called “factor area to be presented”). Factor area specifying section 150 has viewing area specifying section 151 and unnoticed area specifying section 152 .
[0044] Viewing area specifying section 151 specifies, in time unit, a viewing area corresponding to the visual field of the driver of the first vehicle (hereinbelow, simply called “viewing area”) in a predetermined period immediately before the time of occurrence of a potential incident. The viewing area is defined as the geographical area according to the field of view of the driver. The specification is performed since a time point just before the first vehicle enters an intersection until a time point when a potential incident occurs on the basis of positions and orientations in time units.
[0045] Unnoticed area specifying section 152 determines that the second vehicle is an object of an incident/potential incident if the second vehicle is located in the viewing area of the first vehicle since the time point just before the first vehicle enters an intersection until the time point of occurrence of a potential incident. In the viewing area, the region on the inside of lines connecting both ends of the second vehicle which can be viewed from the first vehicle and the first vehicle will be called an “unnoticed area” to which the driver of the first vehicle does not pay attention. That is, the unnoticed area is an area which is in the area of the visual field to which the driver can pay attention but does not actually pay attention. The unnoticed area is defined as the geographical area where the driver did not pay attention to.
[0046] Factor area presenting section 160 obtains map data of the place of occurrence of a potential incident from map data storing section 140 . Factor area presenting section 160 displays the unnoticed area as the incident/potential incident factor area to be noticed more so as to be overlapped on the map data.
[0047] Incident/potential-incident factor area specifying apparatus 100 has, although not illustrated, for example, a CPU (Central Processing Unit), a storing medium such as an RAM (Random Access Memory), an operation section made by a plurality of key switches and the like, and a display section made by a liquid crystal display or the like. In this case, each of the function sections is implemented by the CPU executing a control program.
[0048] Incident/potential-incident factor area specifying apparatus 100 configured as described above can specify an incident/potential-incident factor area having great need of presentation from the relation between the position of the incident/potential-incident object and the viewing area of the driver. That is, incident/potential-incident factor area specifying apparatus 100 can specify an area corresponding to the position of the incident/potential-incident object existing in the viewing area of the driver just before occurrence of a potential incident, as an area which can be seen but is not actually seen by the driver. Incident/potential-incident factor area specifying apparatus 100 can set the area as an unnoticed area which is one of the incident/potential-incident factor areas.
[0049] A viewing area and an unnoticed area in the present embodiment will now be described.
[0050] FIGS. 2 and 3 are schematic views for explaining a viewing area and an unnoticed area. FIG. 2 illustrates a state at time “t” when a potential incident occurs between first and second vehicles. FIG. 3 is a diagram illustrating a viewing area and an unnoticed area of each of the vehicles at time t−Δt just before a potential incident occurs.
[0051] In the example illustrated in FIG. 2 , it is assumed that a potential incident occurs between first vehicle 211 and second vehicle 212 (vehicles 211 and 212 come close to collision) in intersection 210 . Second vehicle 212 is an object of an incident/potential incident. As described above, although first vehicle 211 is determined as a vehicle as a reference for specifying the incident/potential-incident factor area, the opposite situation can be applied. That is, when second vehicle 212 is determined as a vehicle as a reference for specifying the incident/potential-incident factor area, first vehicle 211 can be the incident/potential-incident object for second vehicle 212 .
[0052] First viewing area 213 corresponding to the effective visual field of the driver of first vehicle 211 extends in the travel direction of first vehicle 211 . Viewing area 214 corresponding to the effective visual field of the driver of second vehicle 212 extends in the travel direction of second vehicle 212 . In Non-Patent Literature 3, the effective visual field is defined as a peripheral area of points of regard in which a perceiver can retrieve, discriminate, process or store information on a given issue. In the present embodiment, the effective visual field is defined as an area in which the driver can notice the presence of a vehicle when the driver pays attention.
[0053] As illustrated in FIG. 2 , second vehicle 212 is located in first viewing area 213 . Therefore, when the driver of first vehicle 211 notices the presence of second vehicle 212 at the earliest possible timing before a potential incident, there is a high possibility that the potential incident can be prevented. In other words, in spite of the fact that second vehicle 212 was located in first viewing area 213 , there is a high possibility that the driver of first vehicle 211 did not pay attention to second vehicle 212 .
[0054] As illustrated in FIG. 3 , if second vehicle 212 is located in first viewing area 213 at time t−Δt immediately before a potential incident, incident/potential-incident factor area specifying apparatus 100 sets an area corresponding to the location of second vehicle 212 , as unnoticed area 215 . Incident/potential-incident factor area specifying apparatus 100 presents unnoticed area 215 as an incident/potential incident factor area which is highly likely to be a factor of a potential incident.
[0055] The operations of incident/potential-incident factor area specifying apparatus 100 will now be described.
[0056] FIG. 4 is a flowchart showing an example of operations of incident/potential-incident factor-area specifying apparatus 100 .
[0057] First, in step S 1000 , incident/potential-incident determining section 120 selects the range of performing analysis for specifying the incident/potential-incident factor area. For example, when a specific intersection, date, and time zone are designated by operation of an operator or the like, incident/potential-incident determining section 120 selects time-series data corresponding to a designated object as an analysis object. Incident/potential-incident factor area specifying apparatus 100 may execute the processes in steps S 2000 to S 5000 to be described later only for a designated first vehicle. Incident/potential-incident factor area specifying apparatus 100 may handle, as first vehicles, all of vehicles which enter an intersection as an analysis object within a time zone as an analysis object, and execute the processes in steps S 2000 to S 5000 for each of the first vehicles.
[0058] In step S 2000 , incident/potential-incident determining section 120 executes an incident/potential-incident determining process for determining whether a potential incident occurs in the selection object or not. The details of the process will be described later.
[0059] In step S 3000 , factor area specifying section 150 determines whether a potential incident occurs or not. If a potential incident occurs (YES in S 3000 ), factor area specifying section 150 proceeds to step S 4000 .
[0060] In step S 4000 , factor area specifying section 150 executes an unnoticed area specifying process of specifying an unnoticed area. The details of the process will be described later.
[0061] In step S 5000 , on the basis of they incident/potential-incident factor area, factor area presenting section 160 obtains map data of an intersection where a potential incident occurs, from map data storing section 140 . Factor area presenting section 160 displays the incident/potential-incident factor area so as to be overlapped on the obtained map data. The state of the display screen is as illustrated in, for example, FIG. 3 .
[0062] FIG. 5 is a flowchart showing an example of the incident/potential-incident determining process (step S 2000 ) in Embodiment 1.
[0063] First, incident/potential-incident determining section 120 selects one time in a time zone to be analyzed from time-series data to be analyzed and obtains the location of the first vehicle at the time (S 2001 ). Incident/potential-incident determining section 120 determines whether the second vehicle exists or not at the selected time (S 2002 ).
[0064] It is now assumed that incident/potential-incident determining section 120 handles a vehicle which encounters with the first vehicle in any intersection and at any time as a second vehicle. Each time another first vehicle enters an intersection, incident/potential-incident determining section 120 handles a vehicle which encounters with the first vehicle as a second vehicle. The same vehicle may be a second vehicle for a different first vehicle. To simplify the description, it is assumed that at most one second vehicle exists as an analysis object. If two or more second vehicles exist at the same time, incident/potential-incident determining section 120 may execute the processes in steps S 2002 to S 2012 to be described later for each of the detected second vehicles.
[0065] If the second vehicle exists at selected time (YES in S 2002 ), incident/potential-incident determining section 120 obtains the location of the second vehicle at the selected time from the time-series data to be analyzed (S 2003 ). Incident/potential-incident determining section 120 calculates the distance between the first and second vehicles at the selected time (S 2004 ).
[0066] Incident/potential-incident determining section 120 determines whether the calculated distance is shorter than a predetermined distance threshold or not (S 2005 ). If the calculated distance is shorter than the distance threshold (YES in S 2005 ), incident/potential-incident determining section 120 obtains the speed at each of time of the first vehicle in a predetermined time range before and after the selected time from the time-series data to be analyzed (S 2006 ). From the obtained speed of the time series, incident/potential-incident determining section 120 calculates acceleration of the first vehicle at the selected time (S 2007 ).
[0067] Incident/potential-incident determining section 120 determines whether the calculated acceleration is equal to or less than a predetermined acceleration threshold or not (S 2008 ). If the calculated acceleration is equal to or less than the acceleration threshold (NO in S 2008 ), incident/potential-incident determining section 120 proceeds to step S 2009 . Incident/potential-incident determining section 120 obtains the travel direction (orientation) at each time of the first vehicle in the predetermined time range before and after the selected time from the time-series data to be analyzed (S 2009 ). Incident/potential-incident determining section 120 determines whether a change in the travel direction is larger than a predetermined direction change threshold or not from the obtained travel direction in the time series (S 2010 ).
[0068] If the acceleration is larger than the acceleration threshold (YES in S 2008 ), incident/potential-incident determining section 120 proceeds to step S 2011 . If the change in the travel direction is larger than the direction change threshold (YES in S 2010 ), incident/potential-incident determining section 120 proceeds to step S 2011 . Incident/potential-incident determining section 120 determines whether at least one of the condition that the acceleration is larger than the acceleration threshold and the condition that the change in the travel direction is larger than the direction change threshold is satisfied or not. When at least one of the two conditions is satisfied, incident/potential-incident determining section 120 determines that a potential incident occurs (S 2011 ). Incident/potential-incident determining section 120 identifies the first vehicle as an object for specifying the incident/potential-incident factor area, and identifies the second vehicle as an incident/potential-incident object. Incident/potential-incident determining section 120 identifies the selected time as potential-incident occurrence time and identifies the intersection where the first vehicle is located at the selected time, as a potential-incident occurrence location (S 2012 ). Incident/potential-incident determining section 120 outputs identification results to factor area specifying section 150 and returns to the processes in FIG. 4 .
[0069] If the calculated distance is shorter than the distance threshold at the selected time (NO in S 2005 ), incident/potential-incident determining section 120 returns to step S 2001 . If the acceleration. is. equal to or less than the acceleration threshold and the travel direction change is equal to or less than the direction change threshold (NO in S 2008 and NO in S 2010 ), incident/potential-incident determining section 120 returns to step S 2001 . Incident/potential-incident determining section 120 designates the next time from the analysis object and repeats the process. If no second vehicle exists in the analysis object (NO in S 2002 ), incident/potential-incident determining section 120 returns to the process of FIG. 4 .
[0070] FIG. 6 is a flowchart showing an example of the unnoticed area specifying process (step S 4000 ).
[0071] First, factor area specifying section 150 selects time by going back the time from the potential-incident occurrence time “t” by a predetermined time interval (S 4001 ). Factor area specifying section 150 determines whether or not both the first vehicle and the incident/potential-incident object exist in the intersection as the potential-incident occurrence location at the selected time (S 4002 ). While both of the first vehicle and the incident/potential-incident object exist in the intersection as the potential-incident occurrence location (YES in S 4002 ), factor area specifying section 150 repeats the processes in following steps S 4003 to S 4009 . That is, the processes in the steps S 4003 to S 4009 are repeated until at least one of the first vehicle and the incident/potential-incident object does not exist in the intersection.
[0072] In step S 4003 , factor area specifying section 150 obtains the position, travel direction (orientation) and speed of the first vehicle at the selected. time from the time-series data (S 4003 ). Factor area specifying section 150 obtains intersection shape information of an intersection as the potential-incident occurrence location from the intersection data stored in intersection data storing section 130 (S 4004 ).
[0073] Factor area specifying section 150 sets a first viewing area (area corresponding to the effective visual field of the driver of the first vehicle) at the selected time from the position, travel direction, and speed, which are obtained, of the first vehicle (S 4005 ). Preferably, factor area specifying section 150 excludes a blind area which cannot be seen from the driver of the first vehicle, from the first viewing area on the basis of the geometric shape of the intersection, incidental facilities, the positions and sizes of buildings, and the like.
[0074] Factor area specifying section 150 sets the first viewing area in accordance with the visual feature of a human. being.
[0075] For example, as described in Non-Patent Literature 1, the sensitivity of the retina of a human being is high only in the center portion. More specifically, the range in which resolution is high and close to eyesight measured in an eye test is 2° around the point of regard (the range of 35 cm around the point of regard in location 10 m ahead). The sensitivity decreases to 20% of that in the center, in distance apart from the center by 10°. The effective visual field, is usually the range of about 4° to 20° in the peripheral visual field around the central vision and changes according to a psychological factor.
[0076] For example, as described in Non-Patent Literature 2, the dynamic vision of a moving human being decreases significantly with advancing age, and decreases as the walking speed of a human being or moving speed of an object increases. The dynamic vision of a moving human being is the eyesight when he/she who is moving sees a moving object, The dynamic visual field is narrowed as the walking speed of a human being increases, like the dynamic vision. The dynamic visual field is a range which can be seen by a human being who is moving without changing the position of his/her eyes.
[0077] On the basis of the visual feature, for example, factor area specifying section 150 sets, as the first viewing area, a fan-shaped area which opens at predetermined angle θ in the direction of the velocity vector of the first vehicle around the position of the first vehicle as a center (the blind area may be excluded). Factor area specifying section 150 defines, for example, the angle θ of the fan shape as following equation 1 using the maximum value 20° of the effective visual field and velocity “v” of the first vehicle.
[0000] θ( v )=−1 e −5 ×v 3 −0.0007× v 2 +0.0008× v +20 (Equation 1)
[0078] Subsequently, factor area specifying section 150 obtains the position of an incident/potential-incident object at selected time from time-series data (S 4006 ) and determines whether or not an incident/potential-incident object exists in the set first viewing area (S 4007 ). If an incident/potential-incident object does not exist in the first viewing area (NO in S 4007 ), factor area specifying section 150 returns to step S 4001 , designates the next time, and repeats the process.
[0079] If an incident/potential-incident object exists in the first viewing area (YES in S 4007 ), the process proceeds to step S 4008 . Factor area specifying section 150 sets, as an unnoticed area, an area on the inside of a line segment connecting the position of the first vehicle and the positions at both ends of the second vehicle which is an incident/potential-incident object and which can be visually recognized from the first vehicle (S 4008 ). Factor area specifying section 150 may set, as an unnoticed area, the entire area extending in a direction from the position of the first vehicle toward the position of an incident/potential-incident object, in the first viewing area. Alternately, factor area specifying section 150 may set, as an unnoticed area, only the area up to the area in which the incident/potential-incident object is located, in the direction from the position of the first vehicle toward the position of an incident/potential-incident object.
[0080] Factor area specifying section 150 specifies, as a noticed area, an area obtained by excluding the unnoticed area from the first viewing area (S 4009 ). After that, factor area specifying section 150 returns to step S 4001 , designates the next time, and repeats the process. Factor area specifying section 150 may specify, as a noticed area, an area obtained by excluding the unnoticed area and an over-noticed area from the first viewing area.
[0081] If any of the first vehicle and the incident/potential-incident object does not exist in the intersection as the potential-incident occurrence location (NO in S 4002 ), factor area specifying section 150 specifies the incident/potential-incident factor area on the basis of the set unnoticed area.
[0082] Factor area specifying section 150 may set the unnoticed area at each time as the incident/potential-incident factor area at the time. Factor area specifying section 150 may set an area obtained through the logical OR operation on the unnoticed areas at respective time points in a continuous time zone, as the incident/potential-incident factor area in a time zone just before a potential incident. Factor area specifying section 150 may set an area obtained through the logical OR operation on the unnoticed areas at respective time points in discrete time points or time zones (for example, the same time point or time zone in different days), as an incident/potential-incident factor area in a time zone just before a potential incident. Factor area specifying section 150 may set, as an incident/potential-incident factor area, an area where a time integral of a time period of the existence of the unnoticed area in a continuous time zone or in discrete time points or time zones is a predetermined value or larger. Factor area specifying section 150 may set, as an incident/potential-incident factor area in a time zone just before a potential incident, only the unnoticed area at any time.
[0083] Factor area specifying section 150 outputs a specified incident/potential-incident factor area to factor area presenting section 160 and returns to the process of FIG. 4 . At this time, factor area specifying section 150 also outputs the occurrence time of a potential incident, the position and orientation of the first vehicle and the incident/potential-incident object at each time, and a noticed area to factor area presenting section 160 . The result is displayed by factor area presenting section 160 in such a manner that the incident/potential-incident factor area is overlapped on the map data of the intersection where the potential incident occurs. Factor area presenting section 160 may display only a portion overlapping a road area as the incident/potential-incident factor area with reference to the structure data of the intersection. Further, factor area presenting section 160 may display, as an incident/potential-incident factor area, only a portion which does not overlap the building area and incidental facilities such as a footbridge with reference to data on a building in the periphery of the intersection.
[0084] As described above, if the incident/potential-incident object is located in the viewing area of the driver of the vehicle immediately before a potential incident, incident/potential-incident factor area specifying apparatus 100 according to the present embodiment presents the unnoticed area corresponding to the location of the incident/potential-incident object, as an incident/potential-incident factor area. In such a manner, an incident/potential-incident factor area which is likely to be a factor of a potential incident and having great need of presentation is specified, and a presentation object can be narrowed to such an area. That is, incident/potential-incident factor area specifying apparatus 100 can call for attention or present a potentially dangerous area with respect to a potential incident caused by paying no attention to an incident/potential-incident object even though the object exists in the effective visual field. Therefore, presentation of even an area which is not likely to be a factor of a potential incident can be prevented, and troublesomeness of an information user such as a driver can be reduced.
Embodiment 2
[0085] The area which is likely to be a factor of a potential incident includes not only the unnoticed area described in Embodiment 1 but also an “area noticed more than necessary”. For example, in the case where the driver has to pay more attention to a second vehicle as an incident/potential-incident object which comes from the right direction but pays too much attention to another third vehicle which comes from the left direction, an area in the left direction is an area to which attention is paid more than necessary. That is, the area in the left direction is an area as a factor of a potential incident.
[0086] The incident/potential-incident factor area specifying apparatus according to Embodiment 2 of the present invention sets the area to which attention is paid more than necessary as an “over-noticed area”, and presents the unnoticed area and the over-noticed area as incident/potential-incident factor areas. The over-noticed area is defined as the geographical area where the driver paid over-attention to.
[0087] FIG. 7 is a block diagram illustrating an example of the configuration of an incident/potential-incident factor area specifying apparatus according to Embodiment 2 of the present invention, and corresponds to FIG. 1 in Embodiment 1. The same reference numerals are designated to the same parts as those of FIG. 1 , and their description will not be repeated.
[0088] In FIG. 7 , factor area specifying section 150 a of incident/potential-incident factor area specifying apparatus 100 a .according to the present embodiment newly has over-noticed area specifying section 153 a.
[0089] If another object which is likely to be noticed by the driver of the first vehicle is located in the first viewing region except for the incident/potential-incident object, over-noticed area specifying section 153 a sets the area corresponding to the location of the object, as an over-noticed area. Over-noticed area specifying section 153 a outputs the over-noticed area as an incident/potential-incident factor area to factor area presenting section 160 .
[0090] FIGS. 8 and 9 are schematic views for explaining an over-noticed area and correspond to FIGS. 2 and 3 of Embodiment 1. The same reference numerals are designated to the same components as those of FIGS. 2 and 3 , and their description will not be repeated.
[0091] As illustrated in FIGS. 8 and 9 , viewing area 222 corresponding to the effective visual field of the driver of third vehicle 221 extends in the travel direction of first vehicle 211 . At time t−Δt just before time “t” when a potential incident between first and second vehicles 211 and 212 occurs, third vehicle 221 is located in a direction different from unnoticed area 215 in first viewing area 213 . The possibility that the driver of first vehicle 211 pays too much attention to third vehicle 221 just before a potential incident with second vehicle 212 and does not notice the presence of second vehicle 212 is high.
[0092] In the present embodiment, it is assumed that third vehicle 221 as a vehicle which is not an incident/potential-incident object (hereinbelow, called an “over-noticed object”) is located in first viewing area 213 at time t−ΔM just before a potential incident. Over-noticed area specifying section 153 a sets, as over-noticed area 223 , the area corresponding to the location of third vehicle 221 . Factor area presenting section 160 presents also over-noticed area 223 as the incident/potential-incident factor area.
[0093] FIG. 10 is a flowchart showing an example of operations of incident/potential-incident factor area specifying apparatus 100 a according to the present embodiment and corresponds to FIG. 4 of Embodiment 1. The same reference numerals are designated to the same components as those of FIG. 4 , and their description will not be repeated.
[0094] If the unnoticed area is specified in step S 4000 , over-noticed area specifying section 153 a executes an over-noticed area specifying process of specifying an over-noticed area in step S 4100 a. The details of the process will be described later.
[0095] In the present embodiment, factor area presenting section 160 presents, as incident/potential-incident factor areas, the unnoticed area and the over-noticed area so as to be distinguished from each other by different colors or the like. That is, in the present embodiment, factor area presenting section 160 displays the incident/potential-incident factor areas for the respective factors so as to be overlapped on the map data of the intersection.
[0096] FIG. 11 is a flowchart showing an example of the over-noticed area specifying process (step 4100 a ). The over-noticed area specifying process is partly the same as the unnoticed area specifying process described with reference to FIG. 6 of Embodiment 1. Therefore, the same step numbers are designated to the same processes as those in FIG. 6 , and the description will be omitted appropriately.
[0097] First, over-noticed area specifying section 153 a selects time (S 4001 ) and, if the first vehicle, the incident/potential-incident object, and the third vehicle are present in an intersection (YES in S 4002 a ), proceeds to step S 4003 . Over-noticed area specifying section 153 a executes the processes in steps S 4003 to S 4005 to set the first viewing area.
[0098] It is assumed that over-noticed area specifying section 153 a handles, as a third vehicle, a vehicle which encounters with the first vehicle and the incident/potential-incident object in any intersection and at any time. To simplify the description, it is assumed that at most one third vehicle exists as an analysis object.
[0099] Over-noticed area specifying section 153 a obtains the location of the third vehicle at the selected time from the time-series data (S 4006 a ) and determines whether the third vehicle exits in the set first viewing area or not (S 4007 a ). If there is no third vehicle in the first viewing area (NO in S 4007 a ), over-noticed area specifying section 153 a returns to step S 4001 .
[0100] If the third vehicle exists in the first viewing area (YES in S 4007 a ), the process proceeds to step S 4008 a. Over-noticed area specifying section 153 a sets, as an over-noticed area, an area in the first viewing area and on the inside of a line segment connecting the positions at both ends of the third vehicle (over-noticed object) which can be visually recognized from the first vehicle and the position of the first vehicle (S 4008 a ). Over-noticed area specifying section 153 a may set, as the over-noticed area, the entire area extending in a direction from the position of the first vehicle toward the position of the third vehicle in the first viewing area. Alternately, over-noticed area specifying section 153 a may set, as an over-noticed area, only the area up to the area where the third vehicle is located, in the direction from the position of the first vehicle to the position of the third vehicle.
[0101] Over-noticed area specifying section 153 a specifies, as a noticed area, an area obtained by excluding the unnoticed area from the first viewing area (S 4009 a ). After that, over-noticed area specifying section 153 a returns to step S 4001 .
[0102] If any of the first vehicle, the incident/potential-incident object, and the third vehicle does not exist in the intersection as the potential-incident occurrence location (NO in S 4002 a ), over-noticed area specifying section 153 a specifies the incident/potential-incident factor area on the basis of the set noticed area.
[0103] Over-noticed area specifying section 153 a may set the over-noticed area at each time as the incident/potential-incident factor area (that is, an over-noticed area) at the time. Over-noticed area specifying section 153 a may set an area obtained through the logical OR operation on the over-noticed areas at respective time points in a continuous time zone, as the incident/potential-incident factor area in a time zone just before a potential incident. Over-noticed area specifying section 153 a may set an area obtained through the logical OR operation on the over-noticed areas at respective time points in discrete time points or time zones (for example, the same time point or time zone in different days), as an incident/potential-incident factor area in a time zone just before a potential incident. Over-noticed area specifying section 153 a may set an area obtained through the logical OR operation on all of the over-noticed areas obtained in time series as the incident/potential-incident factor area in a time zone just before a potential incident. Over-noticed area specifying section 153 a may set, as an incident/potential-incident factor area, an area where a time integral of a time period of the existence of the over-noticed area in a continuous time zone or in discrete time points or time zones is a predetermined value or larger. Over-noticed area specifying section 153 a may set, as an incident/potential-incident factor area in a time zone just before a potential incident, only the over-noticed area at any time.
[0104] As described above, if a third vehicle different from an incident/potential-incident object is present in the first viewing area just before a potential incident, incident/potential-incident factor area specifying apparatus 100 a according to the present embodiment sets the area corresponding to the location of the third vehicle, as an over-noticed area. Incident/potential-incident factor area specifying apparatus 100 a presents, as the incident/potential-incident factor areas, the unnoticed area and the over-noticed area so as to be distinguished from each other. In such a manner, incident/potential-incident factor area specifying apparatus 100 a can call for attention or present a potentially dangerous area with respect to a potential incident caused by another area to which too much attention is paid.
[0105] Incident/potential-incident factor area specifying apparatus 100 a may detect a plurality of third vehicles, set a plurality of candidates of over-noticed areas, and specify one or more over-noticed areas from the candidates. In this-case for example, over-noticed area specifying section 153 a sets the size of each of the over-noticed areas as the degree of over-notice, and arranges the over-noticed areas in descending order of the degree of over-notice. The over-notice area specifying section 153 a controls the number of over-noticed areas which can be recognized according to the speed of the vehicle by using the degree of over-notice and outputs the over-notice areas as an incident/potential-incident factor area, to factor area presenting section 160 .
Embodiment 3
[0106] The area which is likely to be a factor of a potential incident also includes an area in which an incident/potential incident object existed in a blind area as the blind area of the first vehicle (hereinbelow, called “factor blind area”). An incident/potential-incident factor area specifying apparatus according to Embodiment 3 of the present invention presents the unnoticed area and the factor blind. area as incident/potential-incident factor areas.
[0107] FIG. 12 is a block diagram illustrating an example of the configuration of the incident/potential-incident factor area specifying apparatus according to Embodiment 3 of the present invention and corresponds to FIG. 1 of Embodiment 1. The same reference numerals are designated to the same parts as those of FIG. 1 , and their description will not be repeated.
[0108] In FIG. 12 , factor area specifying section 150 b of incident/potential-incident factor area specifying apparatus 100 b according to the present embodiment newly has factor blind area specifying section 154 b.
[0109] If an incident/potential-incident object is located in a blind area which cannot be seen from the driver of the first vehicle due to a building or the like in the periphery, factor blind area specifying section 154 b specifies the area corresponding to the blind area as a factor blind area. Factor blind area specifying section 154 b outputs the factor blind area as an incident/potential incident factor area to factor area presenting section 160 .
[0110] FIGS. 13 and 14 are schematic views for explaining a factor blind area and correspond to FIGS. 2 and 3 of Embodiment 1. The same reference numerals are designated to the same components as those of FIGS. 2 and 3 , and their description will not be repeated. The positions and orientations of the first and second vehicles are different from those of FIGS. 2 and 3 .
[0111] FIG. 13 illustrates a state where a potential incident occurs at time t=1. FIG. 14 illustrates a scene in which blind area 232 was present due to building 231 in first viewing area 213 at immediately preceding time t−Δt. It is assumed that second vehicle 212 as an incident/potential-incident object was located in blind area 232 . In this case, if the driver of first vehicle 211 is aware of the possibility of the presence of second vehicle 212 in blind area 232 , the possibility of preventing the potential incident is high.
[0112] If second vehicle 212 is located in blind area 232 existing in first viewing area 21 . 3 at time t−Δt just before a potential incident, incident/potential-incident factor area specifying apparatus 100 b sets blind area 232 as a factor blind area. Incident/potential-incident factor area specifying apparatus 100 b presents the factor blind area as the incident/potential-incident factor area.
[0113] FIG. 15 is a flowchart showing an example of operations of the incident/potential-incident factor area specifying apparatus according to the present embodiment and corresponds to FIG. 4 of Embodiment 1. The same reference numerals are designated to the same components as those of FIG. 4 , and their description will not be repeated.
[0114] If the unnoticed area is specified in step S 4000 , factor blind area specifying section 154 b executes a factor blind area specifying process of specifying a factor blind area in step S 4200 b. The details of the process will be described later.
[0115] In the present embodiment, factor area presenting section 160 presents, as incident/potential-incident factor areas, the unnoticed area and the factor blind area so as to be distinguished from each other by different colors or the like. That is, in the present embodiment, factor area presenting section 160 displays the incident/potential-incident factor areas for the respective factors so as to he overlapped on the map data of the intersection.
[0116] FIG. 16 is a flowchart showing an example of the factor blind area specifying process (step 4200 b ). The factor blind area specifying process is partly the same as the unnoticed area specifying process described with reference to FIG. 6 of Embodiment 1. Therefore, the same step numbers are designated to the same processes as those in FIG. 6 , and the description will be omitted appropriately.
[0117] First, factor blind area specifying section 154 b executes the processes in steps S 4003 to S 4005 to set the first viewing area at all of time points when the first vehicle and the incident/potential-incident object are present in the intersection.
[0118] Factor blind area specifying section 154 b determines whether a blind area in which an incident/potential-incident object is hidden exists or not.
[0119] The presence/absence of the blind area is determined by, for example, as follows. First, from intersection data, factor blind area specifying section 154 b retrieves an incidental facility and a building positioned between the first vehicle and the incident/potential-incident object, and obtains the information of the positions and the areas of them. Factor blind area specifying section 154 b sets an area over the building and the like when viewed from the first vehicle, in the first viewing area as a blind area in which an incident/potential-incident object is hidden.
[0120] If a blind area in which an incident/potential-incident object is hidden is absent (NO in S 4007 b ), factor blind area specifying section 154 b returns to step S 4001 . On the other hand, if a blind area in which an incident/potential-incident object is hidden is present (YES in S 4007 b ), factor blind area specifying section 154 b sets the blind area as the factor blind area (S 4008 b ) and returns to step S 4001 .
[0121] Factor blind area specifying section 154 b may set the factor blind area at each time as the incident/potential-incident factor area at the time. Factor blind area specifying section 154 b may set an area obtained through the logical OR operation on all of factor blind areas obtained in time series, as the incident/potential-incident factor area in a time zone just before a potential incident. Factor blind area specifying section 154 b may set, as an incident/potential-incident factor area, an area where a time integral of a time period of the existence of the factor blind area is a predetermined value or larger. Factor blind area specifying section 154 b may set, as an incident/potential-incident factor area in a time zone just before a potential incident, only the factor blind area at any time.
[0122] As described above, if an incident/potential-incident object is present in the blind area of the first vehicle just before a potential incident, incident/potential-incident factor area specifying apparatus 100 b according to the present embodiment specifies the blind area as a factor blind area. Incident/potential-incident factor area specifying apparatus 100 b presents, as the incident/potential-incident factor areas, the unnoticed area and the factor blind area so as to be distinguished from each other. In such a manner, incident/potential-incident factor area specifying apparatus 100 b can call for attention or present a potentially dangerous area with respect to a potential incident caused by not paying attention to the factor blind area. Incident/potential-incident factor area specifying apparatus 100 b may further include over-noticed area specifying section 153 a of Embodiment 2 and present also an over-noticed area as the incident/potential-incident factor area.
[0123] The method of specifying the first viewing area is not limited to the methods (shape, calculation equation, and parameters of setting) described in the foregoing embodiments. For example, the incident/potential-incident factor area specifying apparatus may change a viewing area in accordance with the age of the driver, individually set parameters related to the viewing area, and feedback a parameter from measurement values related to the visual sense of the driver, the position of the head, operation, and the like. The incident/potential-incident factor area specifying apparatus may preliminarily obtain the direction in which the driver intends to drive, from the information of winkers and behavior of the vehicle and change the shape of the viewing area in accordance with the obtained direction. in this case, for example, the incident/potential-incident factor area specifying apparatus may set a shape having a center in the direction in which the driver intends to drive, instead of a shape having a center along the velocity vector of the vehicle.
[0124] The occurrence of a potential incident is not limited to the above-described one. For example, the incident/potential-incident factor area specifying apparatus may determine, as occurrence of a potential incident, for example, disobedience of traffic regulation such as ignorance of a traffic light or stop sign violation, abrupt acceleration, accidental contact, and occurrence of an incident.
[0125] The method of determining the over-noticed area is not limited to the above-described one. For example, when a plurality of candidates of over-noticed areas area set, the incident/potential-incident factor area specifying apparatus may employ an attribute other than the size of the over-noticed area as the degree of over-notice. Such an attribute is, for example, distance from an unnoticed area, the number of vehicles in the over-noticed area, the number of vehicles driving in the over-noticed area, the number of vehicles stopped in the over-noticed area, the number of vehicles driving in the viewing area, or the number of vehicles stopped in the viewing area.
[0126] The incident/potential-incident factor area specifying apparatus does not always have to have the time-series data storing section, the intersection data storing section, the map data storing section, and the factor area presenting section. In this case, for example, the incident/potential-incident factor area specifying apparatus obtains data from an external information server via a communication network, and outputs information of the incident/potential-incident factor area to an external display apparatus. When the occurrence place and occurrence time of a potential incident are clear, the incident/potential-incident factor area specifying apparatus does not have to have the incident/potential-incident determining section.
[0127] The object which can be a cause of a potential incident is not limited to a vehicle. For example, objects to be noticed include a pedestrian, a traffic light, and a sign. For example, when a traffic light stands in a location where it is not easily seen, although it exists in the viewing area, there is the possibility that the driver misses the red light and a potential incident occurs. When the present invention is applied to such a case, it is understood that the area corresponding to the position of the traffic light is the incident/potential-incident factor area (unnoticed area).
[0128] The incident/potential-incident factor area specifying apparatus according to each of the foregoing embodiments can provide the incident/potential-incident factor area as incident prediction information, incident statistical information, and incident analysis information to a driver, a road administrator who performs safety design and improvement of roads, a police officer who makes an inspection of a traffic incident and a. traffic safety campaign, an incident appraiser conducting an incident analysis, an insurer making an incident analysis, and the like.
[0129] The disclosure of Japanese Patent Application No. 2010-223889, filed on Oct. 1, 2010, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
INDUSTRIAL APPLICABILITY
[0130] The present invention is useful as an incident/potential-incident factor area specifying apparatus and an incident/potential-incident factor area specifying method capable of specifying an incident/potential-incident factor area which has to be surely presented. That is, the present invention is suitable for a preventive safety system, a drive assist system, a traffic incident preventing system particularly for an intersection, a traffic incident factor analysis system, and a traffic incident predicting system.
REFERENCE SIGNS LIST
[0000]
100 , 100 a, 100 b Incident/potential-incident factor area specifying apparatus
110 Time-series data storing section
120 Incident/potential-incident determining section
130 Intersection data storing section
140 Map data storing section
150 , 150 a, 150 b Factor area specifying section
151 Viewing area specifying section.
152 Unnoticed area specifying section
153 a Over-noticed area specifying section
154 b Factor blind area specifying section
160 Factor area presenting section
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Disclosed is an accident/near-miss factor area specifying device capable of specifying accident/near-miss factor areas, the presentation of which is highly required. The accident/near-miss factor area specifying device ( 100 ) is used for specifying accident/near-miss factor areas which a driver of a vehicle should. be aware of in order to prevent an accident, and the device comprises a viewing area specifying unit ( 151 ) for specifying a viewing area of a driver of a vehicle which had a near-miss, immediately before the near-miss occurs, and an unnoticed area specifying unit ( 152 ) wherein, when a near-miss object is located in a viewing area, an area corresponding to the position of the object is treated as an unnoticed area which is one of the accident/near-miss factor areas.
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FIELD OF THE INVENTION
This invention is concerned with improvements in and relating to bonded polyester fiberfill batts, sometimes referred to as battings, especially processes whereby such improved batts with desirable aesthetic and serviceable qualities may be obtained, and to articles incorporating such improved batts.
BACKGROUND OF THE INVENTION
Polyester fiberfill (sometimes referred to as polyester fiberfilling material) is well accepted as a reasonably inexpensive filling and/or insulating material for pillows, cushions and other furnishing materials, including bedding materials, and in apparel, and is manufactured and used in large quantities commercially. For many of these used, as disclosed e.g., in U.S. Patents: Tolliver U.S. Pat. No. 3,772,137; Stanistreet U.S. Pat. No. 4,068,036; Scott U.S. Pat. No. 4,129,675; Pamm U.S. Pat. No. 4,281,042; Frankosky U.S. Pat. No. 4,304,817; Siniscalchi U.S. Pat. No. 4,551,383; and LeVan U.S. Pat. No. 4,869,771, it has been desirable to make bonded batts, e.g., by spraying a resin-bonding agent, usually of an acrylic polymer, or by blending the polyester fiberfill with binder fibers, such as are well known in the art, or by use of both a resin-bonding agent and binder fibers.
To improve the aesthetics of polyester fiberfill, it has often proved desirable to "slicken" the fiberfill with a coating of durable (i.e., wash-resistant) coating that has usually been a silicone, i.e., a cured polysiloxane as disclosed, e.g., by Hofmann U.S. Pat. No. 3,271,189; Mead et al U.S. Pat. No. 3,454,422; Ryan U.S. Pat. No. 3,488,217; Salamon et al U.S. Pat. No. 4,146,674; LeVan, above; Takemoto Oil and Fat Co., Ltd., Japanese Published Application No. 58-214,585(1983); or other types such as the polyalkylene oxide variety disclosed by, e.g., Marcus U.S. Pat. No. 4,818,599.
Despite all the prior suggestions and commercially-available materials, especially for use in premium level apparel products, sleeping bags, and comforters, there still remains a need for an easily prepared, homogeneous batting that is characterized by softness and drapability to conform to the wearer's body, good insulating performance, low levels of fiber leakage through shell fabrics, enhanced durability to laundering by washing/drying or by dry cleaning, and enhanced structural integrity whereby the batting is able to hang freely without the need for having it quilted into small size panels.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a process for preparing a bonded batt, comprising forming a blend of polyester fiberfill, in amount by weight about 70 to about 96%, intimately mixed with a binder fiber, preferably a bicomponent binder fiber, having binder material of melting point lower than the softening point of the polyester fiberfill, in amount by weight about 4 to about 30%, preparing a continuous batt from said blend, said batt having an upper face and a lower face, advancing said batt through one or more spray zones, whereby both faces of the batt are sprayed with resin, in total amount about 10 to about 30% of the weight of the sprayed batt, including the resin, said resin being selected to provide, after curing, a cured resin having a glass transition temperature (Tg) of about 0 degrees Celsius or less, heating the sprayed batt in an oven to cure the resin and soften the binder material, followed by hot-rolling the heated batt to achieve intimate contact between the resin and the fibers in the faces of the batt, and cooling the rolled batt.
The hot rolling is preferably effected by use of heated rolls in a calender or S-wrap configuration.
According to another aspect of the invention, there is provided a bonded batt, comprising polyester fiberfill of 0.2 to 10 dtex per filament, bonded throughout with lower melting binder material (from the binder fiber used in the process) in amount by weight about 2 to about 25% of the weight of the batt, and with upper and lower faces of said batt being sealed with a resin having a glass transition temperature (Tg) of about 0 degrees Celsius or less, in amount about 10 to about 30% of the weight of the batt, whereby the sealing rating (SR, as defined) of said faces is at least 3, said batt having a wash durability (WD, as defined) of at least 3, and a bending stiffness (B, as defined) of about 80 cN/cm 2 or less, preferably about 50 cN/cm 2 or less.
DETAILED DESCRIPTION OF THE INVENTION
Thus, the invention provides fiberfill batts, such as are needed for use in premium apparel, by first preparing a homogeneous blend of polyester fiberfill (70-96% by weight of the blend) and a suitable binder fiber (4-30% by weight of the blend). This blend is converted on a card or garnet to a web which may then be layered or cross lapped to form a batting to whose upper and lower faces is serially applied a suitable latex (e.g., a colloidal dispersion of acrylic polymers and/or copolymers in water, discussed in more detail hereinafter), e.g., by spraying. The sprayed batting is heated, e.g., conveniently by being passed through a heated oven to dry the coating(s) and to polymerize the polymeric component(s) to high molecular weight, and to activate the binder fiber. This may be conveniently done in three passes through such an oven, two to serially cure each coating, after such coating is applied to each face, and a third pass to supplement the other two and to activate the binder fiber in preparation for the hot-rolling. The bonded batt is passed around or through heated rolls (S-wrap or calendering process) to soften and spread the cured resin and ensure its complete and even distribution among the fibers in the two faces (large surfaces) of the batt to prevent fiber leakage through the batt and, if needed, to ensure that the batt is of the desired thickness.
The resins that may be used herein are termed variously, by different manufacturers, as "soft" or "medium", or even "very soft", but are characterized by having second order glass transition temperatures (Tg) of about 0 C or less. They provide both softness and drapability to the batt when used in, e.g., apparel, while acting as barrier to fiber leakage from the batt. The final batts may have a basis weight of 1.5 to 12 oz./yd 2 .(50 to 400 g./m. 2 ) and a thickness of 0.07 to 0.20 inch/oz./yd. 2 (0.05 to 0.15 mm./g./m 2 .). Thus the batts of this invention are prepared from a blend of polyester fiberfill and binder fibers, and the fibers in the faces are sealed by a suitably soft-type resin coating. The polyester fiberfill may all be slickened, e.g., as described herein, or may be blend of slickened and unslickened fibers. The fiberfill may be solid, hollow, or a blend of solid and hollow fibers and is not limited to any type of fiber cross section, i.e., it may be of cruciform, trilobal, Y-shaped, dog bone, scalloped oval, and other non-circular cross sections as well as round. The fiberfill has a denier per filament (dpf) within the range of 0.2 to 10, with a dpf of about 1.65 being singularly preferred, and constitutes about 70 to 96% by weight of the blend. The individual fibers are provided with crimp by conventional means and typically exhibit from 5 to 15 crimps per inch and have a length within the range of 3/4 to 3 inches. The binder fibers constitute from about 4 to 30% by weight of the batt and may be of the sheath/core (s/c), side/side (s/s), or monocomponent types. These may be obtained from (co)polyesters, polyolefins, polyolefin/polyester, polyamide/polyamide, e.g., and the like. Useful types of binder fibers, and their modes of functioning, are described in, e.g., "Nonwovens World", March/April, 1990, page 37. The initial dpf of suitable binder fibers in the blend is typically within the range of 2 to 15 with a dpf of 4 being commonly used. Useful binder fibers include those disclosed in the aforementioned U.S. Patents to Scott, Pamm, Frankosky, and Marcus, together with those shown in Harris et al U.S. Pat. No. 4,732,809; Taniguchi et al U.S. Pat. No. 4,789,592; Tomioka et al U.S. Pat. No. 4,500,384; Hirose et al Japanese Patent Publication Kokai 57-210,015(1982); and others known in the art which will function within the oven temperatures disclosed herein. Preferred binder fibers include the commercially-available "Melty 4080" (Unitika Co., Japan) and the "ES" and " EA" polyolefins (Chisso Corporation, Japan).
The cured resin coating on the batt constitutes about 10 to 30% by weight of the final bonded batt, with 12 to 25% being preferred, and about 18% being singularly preferred. As noted previously, a suitable resin coating has a Tg of about 0 C or less. The useful resins are obtained from commercially-available acrylic and vinyl latex compositions among which are included, e.g., Rhoplex E-32 (Rohm and Haas Co.), TR-934 (Rohm and Haas Co.), X-4280J (Kanebo, Japan), these Hycar® latex compositions of B. F. Goodrich Co.: 26146, 26171, 26322, 26083, 26092, 2671, 26120, 2679, 26796, these latex products of National Starch and Chemical Corporation: NACRYLIC X 4445, NACRYLIC X 788-6007, NACRYLIC X 4483, NACRYLIC X 4460, NACRYLIC X 4260, NACRYLIC X 4425, NACRYLIC X 4465, NACRYLIC 4401, NACRYLIC X 78-3990, NACRYLIC X 78-3997, NACRYLIC X 78-3905, NACRYLIC X 4280, NACRYLIC 4441, NACRYLIC 78-6114, X-LINK 2873, X-LINK 2849, X-LINK 78-6119, X-LINK 2893, X-LINK 2833, X-LINK 78-6004, X-LINK 2813, RESYN 2375, DUR-O-SET E-230, DUR-O-SET E-669, and other commercially-available latexes which are cured to resins whose Tg values are about 0 C or less. Some of such commercially-available resins and their Tg values are listed in brochures, e.g., one by B. F. Goodrich, dated 1989, entitled HYCAR® Acrylic Latexes, and one by National Starch and Chemical Corporation, entitled Binders, Saturants, Laminants.
Preparation of the batts is generally begun by conventional opening and blending of the polyester fiberfill and binder fiber, followed by carding or garnetting to make a web. This web can be layered with other webs from a train of cards or garnets, or it can be cross lapped and combined with other webs to form an unbonded batting. This batting is then sprayed with the latex composition on both sides of the batting and is fed to the oven for curing of the resin and bonding of the binder fibers. The oven treatment is conducted at 150-190 C for 2 to 5 minutes, and is conveniently done in three passes of the batt, as previously noted. The bonded batt is then passed through/around at least two hot rolls having a surface temperature in the range of 150 to 250 C (more than two rolls may be used). The configuration of the batting may be in S-wrap over the rolls to provide maximum contact with the rolls. The latter may have a clearance of from 2 to 5 mm. depending on the final batting thickness desired. Alternatively, the bonded batting may be passed through calender rolls, heated as above. In these treatments, only one roll may be heated, if desired, and the batt is passed through/over the rolls a second time to heat the opposite side of the batt. Contact time on the rolls is from 3 to 25 seconds. The hot roll treatment softens and spreads the resin to ensure its complete and even distribution on the batt surface(s) to prevent fiber leakage and to provide a uniform surface, free of lumps, for comfort and aesthetic performance in use. The batts exhibit the basis weight and thickness ranges previously indicated.
The batts of this invention exhibit desirable levels of thermal resistance or insulation, commonly reported as CLO ratings (see Hwang U.S. Pat. No. 4,514,455). Batts of this invention desirably exhibit a CLO value of at least about 0.36 CLO/ oz./yd. 2 and preferably 0.48 CLO/ oz./yd. 2 or higher.
It is to be understood that the components and processes described herein should be selected to provide the batts of this invention. Care must be taken to select combinations that do so provide. For example, the slickener on the fiber and the latex applied to the batt should be selected so as to adhere sufficiently, so that the final batt may exhibit, for example, sufficient wash durability.
TEST PROCEDURES
CLO ratings are obtained as described in Hwang, above.
Wash durability ("WD") of the batts of this invention is evaluated by the procedures of ASTM D-4770-88. In the Examples, the panels were 24 inches×24 inches in size. Durability ratings are reported for measurements made according to paragraph 8.6.1. Batts of the invention exhibit a rating of 3 or higher (paragraph 8.5 scale).
Fiber leakage or percolation through shell fabric is measured as a sealing rating ("SR") by the method described in LeVan U.S. Pat. No. 4,869,771, with a sealing rating (SR) of 5 being excellent and a sealing rating (SR) of 1 being poor. The batts of this invention exhibit a sealing rating (SR) of 3 or higher.
The softness or drapability of the batts of this invention is measured according to German Industrial Standard 53362 Cantilever (DIN 53362 Cantilever) which determines and totals the bending stiffness ("B") of the batting in machine and cross machine directions; the combined results are related to drapability and softness. Batting samples are cut to 25 cm. length and 2.5 cm. width, and are cut in both machine (MD) and cross machine (XD) directions. Each Test specimen is weighed and its weight recorded as "W". Bend length ("LU") is then determined by sliding the sample horizontally on a platform until the front of the bent sample reaches an angle of 41 degrees and 30 seconds. The following calculation is then made:
B=F.sub.1 (LU÷2).sup.3
where B=bending stiffness in cN/cm. 2
LU=bend length in cm.
F 1 =9.8 (W÷L)
W=weight of the specimen sample in grams
L=sample specimen length in cm.
The batts of this invention exhibit a bending stiffness ("B" being the sum of values determined for MD and XD samples from the batt) of 80 cN/cm. 2 or less.
EXAMPLES
EXAMPLE 1
An 82 lb. sample of polyester staple containing 50 weight percent silicon-slickened fiber of 1.65 dpf and 2 inch cut length and 50 weight percent dry (no slickener) fiber of the same denier and cut length was opened by a conventional mechanical opener and fed to a hopper. In a separate opener was placed 18 lb. of "Melty 4080" binder fiber(4 dpf, 2 inch cut length, 50/50 s/c) which had been pre-opened. The binder fiber was fed to the same hopper containing the staple blend and the fibers were mixed, first by hand, then by mechanical tumbling of the combined actions of the inclined and horizontal aprons.
The mixed fibers were fed to two separate garnets which each produced a continuous web about 60 inches wide and having a basis weight of about 1 oz./yd. 2 (34 g/m. 2 ). Each web was passed through a separate cross lapper which produced a cross lapped batt which was placed on a moving conveyor whose speed was about 8 yd./min(7.3 m./min.). The conveyor collected and combined both cross lapped batts into a final multiple-layered batt having a basis weight of about 2.7 oz./yd. 2 (90 g./m. 2 ). In a continuous operation, this batt was passed into a spray zone where Kanebo's X-4280J latex was applied to the top side of the batt which was then passed into a 3-path oven (sufficient latex was applied to provide 9% by weight cured resin on the batt). This path was at 150 C and the resin was cured and the binder fiber activated during a residence time of about 1 minute in the oven. After the batt exited the oven, it was inverted, latex applied to the top side("new") of the batt, and the batt was carried by a second conveyor to a second path of the oven (170 C) to cure the resin and activate the binder fiber (resin at 9% by weight resulted on this side of the batt to make a total of 18% by weight resin on the batt). The batting was fed to the third path of the oven (170 C) to provide further heating of the batt for an additional minute (total heating is for 3 minutes).
The bonded batt is passed through a pair of hot rolls in S-wrap configuration (roll surfaces at 200 C), with a roll contact time of about 12 seconds; roll separation was 2 mm. The batting is compressed to about one half its original thickness and is wound up into a roll. This batting (18% resin, 18% binder fiber) had a basis weight of 3.33 oz/yd. 2 , a thickness of 0.41 inch, exhibited a wash durability rating of 4, a sealing rating of 5, and total bending stiffness of 22.1 cN/cm. 2 (MD=8.6, XD=13.5).
EXAMPLE 2
In the following Table are reported the properties of other batts of the invention, prepared by the apparatus and processes described in Example 1, above, using the same latex, oven and roll temperatures and times as in Example 1. In the Table, "Fiber A" is the fiber blend of Example 1. In all other indicated "Fibers" ("B", etc.), the binder fiber("Melty 4080") had already been combined with the fiberfill and was not separately added as shown in Example 1.
TABLE__________________________________________________________________________BATTING BASISITEM % % WEIGHT THICKNESS BNO. FIBER BINDER RESIN (OZ/YD2) (INCHES) WD SR MD CD TOTAL__________________________________________________________________________1 A 18 25 3.14 0.41 4 5 33.5 35.6 69.12 A 25 18 2.86 0.35 4 5 20.1 31.1 51.23 B 22 12 2.76 0.35 4 5 23.1 38.1 61.24 C 15 18 3.24 0.31 5 5 14.9 18.8 33.75 D 25 18 3.08 0.33 4 5 13.2 34.6 47.8__________________________________________________________________________
Where Fiber B is a 78/22 (W/W) blend of (1) 5 dtex, solid, round cross-section, 50 mm cut length, polyethylene terephthalate staple bearing a polyalkylene oxideslickener and (2) "Melty 4080" (4 dpf);
Fiber C is a 78/7/15 (W/W/W) blend of (1) solid, round cross-section, silicone-slickened, 3 dpf polyethylene terephthalate staple, (2) 7-hole hollow roundcross-section, silicone-slickened, 5.5 dpf polyethylene terephthalate staple, and (3) "Melty 4080" (4 dpf); and Fiber D is a 75/25 (W/W) blend of (1) 1.65 dpf solid, round cross-section, silicone-slickened, 2 inch cut length polyethylene terephthalate stapleand (2) "Melty 4080" (4 dpf).
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Improved polyester fiberfill batts for apparel and other uses are prepared of polyester fiber and binder fiber, sprayed with a soft resin by oven bonding and hot roll treatment. This provides bonded batting which is characterized by softness and drapability, good insulating performance, low levels of fiber leakage or percolation through shell fabrics, enhanced durability when laundered by washing/drying or by dry cleaning, and enhanced structural integrity whereby it hangs freely without the need for quilting into small size panels.
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BACKGROUND OF THE INVENTION
[0001] The field of the invention relates generally to methods and devices for facilitating transactions between two parties who don't understand each other, such as, for example, two individuals who do not speak the same language. The present invention pertains to transactional flash cards, and a method of using transactional flash cards to perform a transaction with another party who doesn't understand the user. Using the flash cards of the present invention, the user does not need to read, speak or even pronounce a word to the other party to the transaction, but instead may simply present a selected transactional flash card to the other party to communicate the goal and intent of the transaction.
[0002] Existing translational communication aids are conceived to teach or assist a person in learning, reading or speaking a foreign language. This means that such aids are not designed to perform a transaction for the user by clearly communicating the goal of the transaction to another party. Instead, existing translational communication aids are designed to teach someone how to speak and communicate in that foreign language. Transactional flash cards are actually quite the opposite; they circumvent the need to learn, memorize or even pronounce a word or a phrase.
[0003] Existing, traditional translation devices may be difficult to use in performing a specific transaction. This is because translation devices are conceived for different purposes such as lexical (dictionaries) or educational purposes and not specifically for performing a transaction whereby the user does not have to learn, read, speak or even pronounce a word in the other party's language.
[0004] Educational flash cards are known. These cards may contain an image of an object and its name, but are designed to teach an individual to memorize/learn a word. With their elementary vocabulary and their functionality as a teaching device, educational flash cards can not and are not meant to communicate and perform a transaction for a user who doesn't understand and is not understood by the party he or she wants to perform the transaction with. For example a traveler in a foreign place would not be served in conducting a transaction with such educational flash cards. Such an individual needs a more specifically structured device which communicates and performs a transaction for him or her. Such a transaction could be, for example, ordering food in a restaurant where no one speaks the card holder's language. In their structure, educational flash cards do not have at least two basic elements: 1. A name of the goal of the transaction and a statement of intent (such as a phrase to describe the intent to order food) displayed in the language of the second party and in the language of the cardholder, and 2. the essential information regarding the goal of the transaction displayed in the cardholder's language. As in the above example of ordering food, a mere translation of the name of a meal using an educational flash card may not mean anything to the cardholder because he or she would not be familiar with the colloquial nature of the name of a meal. Additionally, there might not even be a name for a particular meal in the cardholder's language (for example it is difficult to translate “chirashi sushi” into English, as one may only spell it phonetically in the latin alphabet, which would not help a cardholder to know what he or she is ordering).
[0005] Dictionaries generally do not contain terms of transactional goals such as the names of merchandise etc. because they are typically used for text translations. They are also not normally useful for visual communications because of their traditionally small print and because they contain negligible imagery.
[0006] Travel brochures may contain imagery with information about a place or custom but are not useful in aiding transactions between two parties who don't speak the same language.
[0007] Travel guides may have short glossaries of useful terms, but contain little if any imagery. They are also organized in a format which makes their use cumbersome in attempting to display an idea or the goal of a transaction to a second party. An additional disadvantage with both travel guides and brochures is that the traveler still has to learn to pronounce a word or phrase correctly to ensure proper understanding by another party. Travel guides and brochures are conceived for an informative, and not a transactional purpose, and as such they aid the user little in performing a transaction.
[0008] In summary, known translation devices are not transactional tools, and as such they provide little assistance to a user in performing a transaction with a second party who doesn't speak the user's language.
[0009] It is the object of the present invention to provide transactional flash cards that will assist the user in performing a transaction with another party without spoken communication between the user and the other party. For example, if the user and the other party speak two different languages it is unnecessary for the user to speak, read, or even pronounce word to of the other party.
SUMMARY OF THE INVENTION
[0010] The present invention provides a method of performing a transaction without the use of spoken communication between the parties to the transaction, comprising the steps of: providing at least one transactional flash card displaying text understandable to the user and different text understandable to the other party and an image, both texts and the image describing the same transaction goal; and selecting the flash card to communicate the transaction goal so that when the user presents the flash card to the other party the goal of the transaction is communicated that party.
[0011] The step of providing at least one transactional flash card may further comprise providing the transactional flash cards with a phrase in separate sets of text, one understandable to the user and a second understandable to the other party describing an intent to perform the same transaction and to achieve the same goal. The step of providing at least one transactional flash card may additionally comprise providing a transactional flash card which displays information additional to the text describing the transaction goal, and which additional text is understandable to user, where such additional information is not displayed as text understandable to the other party. The step of providing at least one transactional flash card may also comprise providing a transactional flash cards having at least one icon containing condensed information about the transaction goal. The step of providing at least one transactional flash card may additionally comprise providing a transactional flash card containing an inquiry as to the price of the transaction. The step of providing at least one transactional flash card may further comprise providing a transactional flash card containing text, or an icon, inquiring whether the second party prefers a particular form of payment. The step of providing at least one transactional flash card may also comprise providing a transactional flash card having an erasable surface.
[0012] In a different embodiment, the step of providing at least one transactional flash card may also comprise providing transactional flash cards as a set of 52 cards, where each flash card in the set comprises a different playing card suit (e.g. hearts, diamonds, spades or clubs) and a different number (e.g. deuce through ace), such that the set comprises a deck of standard playing cards.
[0013] In another embodiment of the present method, the step of providing at least one transactional flash card may further comprise providing a transactional flash card on an electronic device having a computer memory and a display screen, where the step of providing a transactional flash card comprises providing the flash card in the computer memory so that the flash card may be viewed on the display screen. The step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device capable of receiving removable memory media, such as CD, memory stick, etc. The step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device containing at least one prompt to allow the first party to view on the display screen information stored in the removable memory media. The step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device capable of connecting to the internet, where the electronic device has a prompt providing a link to an internet site, and the link may comprise a connection to a financial institution capable of performing payment transactions upon an instruction from a user of the electronic device, or the link may comprise a connection to an internet site capable of providing additional transactional flash cards to the electronic device.
[0014] In yet another embodiment of the present method, the step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device further comprising a calculator capable of performing and displaying at least basic mathematical functions. The step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device capable of calculating and displaying an exchange rate and currency conversion for currencies of at least two different countries. The step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device may also comprise providing an electronic device capable of connecting to the internet and capable of calculating and displaying exchange rates for currencies of at least two different countries, where the electronic device communicates with at least one internet site to automatically obtain and display an exchange rate and currency conversion when the names of two countries and one money amount are input to the device.
[0015] In a further embodiment of the present method, the step of providing at least one transactional flash card may also comprise providing a transactional flash card on an electronic device having a surface on which information may be entered into the device using a stylus, and further where such entered information may be displayed on the screen.
[0016] In a different embodiment of the present method, the step of providing an electronic device may further comprise providing an electronic device having a microphone and a display screen, where the device may record sound entered using the microphone and display a representation of the sound on the display screen.
[0017] In still another embodiment of the present method, the step of providing an electronic device may further comprise providing an electronic device capable of converting text that is understandable to the user holding the electronic device to an audible message that is understandable to another party, where when the user presents the electronic device to the other party, the goal of the transaction is communicated to that other party when that party listens to the audible message.
[0018] The present invention also provides a device for facilitating a transaction having a goal between parties who don't understand each other, comprising at least one transactional flash card having a front side and a back side, at least the front side having a display comprising text understandable to the user and different text understandable to the other party, and an image, where both the texts and the image describe the same transaction goal. The transactional flash card front or back side may also contain a phrase in texts understandable to both parties describing an intent to perform the transaction goal. The transactional flash card front or back side may further contain information understandable to the user that is additional to the text describing the transactional goal and phrase, where the additional information is not understandable to the other party to the transaction. The transactional flash card may also contain an erasable surface. The transactional flash cards may be provided as a set of 52 cards, where each flash card in the set comprises a different playing card suit (e.g. hearts, diamonds, spades or clubs) and a different number (e.g. deuce through ace), such that the set comprises a deck of standard playing cards.
[0019] In another embodiment, the transactional flash cards may be provided on an electronic device having a computer memory and a display screen, where the transactional flash card is displayed in electronic form on the screen. The electronic device may also comprise a calculator. The electronic device may also have a connection enabling communication with the internet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The features and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which like elements are labeled similarly and in which:
[0021] [0021]FIG. 1 is a top view of a transactional flash card of the current invention;
[0022] [0022]FIG. 2 is a top view of a transactional flash card of the current invention displayed on a screen of a portable electronic device;
[0023] [0023]FIG. 3 is a top view of the transactional flash card of FIG. 1 further displaying a question written in the characters of a foreign language;
[0024] [0024]FIG. 4 is a top view of the transactional flash card of FIG. 3 incorporating erasable surfaces;
[0025] [0025]FIG. 5 is a top view of the transactional flash card of FIG. 3, further displaying the flash card on a screen of a portable electronic device;
[0026] [0026]FIG. 6 is a top view of the transactional flash card of FIG. 5 further displaying a question about shipping and delivery on the screen;
[0027] [0027]FIG. 7 is a top view of the transactional flash card of FIG. 5 where the electronic device further comprises a calculator;
[0028] [0028]FIG. 8 is a top view of the transactional flash card of FIG. 5 further comprising a currency converter; and
[0029] [0029]FIG. 9 is a top view of the transactional flash card of FIG. 5 further comprising an interactive surface where transactional information may be entered with an interactive stylus and which information will be displayed in the area of the flash card.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The preferred embodiment discloses a method of performing a transaction between a first party who understands a first language and a second party who understands a second language, where the communication impediment between the two parties is that the two parties don't understand each other's language. Several other impediments in communicating the intent to perform a transaction may exist, such as, for example, where the physical noise level is too high for them to hear each other; or where to the first party a trade specific terminology might be meaningless or hard to remember, but without it a transaction couldn't take place because the second party requires the goal of the transaction to be described with that specific terminology. Having shown further communication impediments we in no way mean to limit the invention to the description of the preferred embodiments, and from other applications for the claimed device may arise from numerous other communication impediments.
[0031] The disclosed method obviates the need for the cardholder to learn, speak or even pronounce a foreign language to describe the goal and the intent of a transaction because the transactional flash cards themselves communicate the desired transaction clearly with a second party who does not speak the language of the first party. The transactional flash cards go allow the cardholder to perform the transaction without the cardholder having to communicate in any other way with the second party.
[0032] The following terminology will be referred to throughout this description. “Cardholder” refers to the person possessing the transactional flash cards. The cardholder may, for example, be a traveler to a foreign country, but there are many applications for the transactional flash cards in the cardholder's homeland, especially in today's multicultural cities. Additionally, communication difficulties are not limited to language difficulties alone therefore other uses might arise from any situation where two parties have difficulties understanding each other (e.g. a high noise level where speech is difficult or impossible; or a very technical, specialized language in which only one party is versed; or any other situation where two parties have difficulties communicating.)
[0033] The term “another or second party” includes any person or group of persons who do not understand the cardholder and who the cardholder tries to transact with by communicating the goal and the intent of a transaction through use of the transactional flash cards. It should be noted that the cardholder will most likely be the initiator of a transactional communication, however, he or she might also be approached by another party and may then use the transactional flash cards to communicate. Typical second parties might be merchants, waiters or any other persons who are approached by the cardholder or are offering to sell a product to the cardholder; or an agent who is providing an experience that the cardholder intends to see, or be part of etc.
[0034] The term “transaction” describes an exchange between two parties. The transactional flash card performs a transaction for the cardholder because it describes three aspects of this transaction: 1. its goal, 2. the intent of the parties to perform the transaction and 3. informs the parties of the goal of the transaction. A goal could be a purchase of a specific product, with the description of the intent being the description of the intent to purchase the same product with a phrase such as: “I would like to buy.” The first two aspects of the transaction are written in both the first and the second parties' language. The third aspect, providing information on the goal of the transaction might comprise additional detailed background information on the product or service in the cardholder's language. This would be particularly helpful, for example, where such a product or service does not exist in the cardholder's country. There are a myriad of goals of transactions with their suitable description of the intent to achieve that goal and information on these various goals. Some examples of descriptions of the intent are verbs like: to purchase, order, buy, acquire, see, be part of etc., all with the goal being the provision of a service or consumable item, entertainment, an experience etc. The description of the goal would be a description of that service, or consumables item, entertainment, experience etc.
[0035] The communication with the second party is twofold: textual and visual: (a) textually the flash cards communicate the name describing the goal of a specific transaction together with a phrase describing the intent to achieve this goal written in the second party's language in its idiomatic characters which are prominently displayed on the flash card; and (b) visually an image of the goal of the specific transaction is displayed on the flash cards.
[0036] The information which transactional flash cards convey to the cardholder is also textual and visual: (a) text is displayed on the transactional flash cards in the card holder's language. This text may be displayed in smaller type than the name of the product. The text information may include a description of the goal of a specific transaction characteristics such as materials, ingredients, time needs etc. In addition, a navigational system comprising small icons may be provided on the face of the transactional flash card to quickly give the user general information while using less written text. This is important because space limitations may exist with the transactional flash cards. For example when the goal of the transaction is the purchase of a product, small icons might tell the cardholder the price ranges and what forms of payment are accepted; (b) an image of the goal of the transaction will also be readily understood by the card holder.
[0037] The transactional flash cards may be presented in the form of printed cards or they may be displayed on the screen of any portable electronic device such as a personal digital assistant (PDA). Currently available PDAs, such as those sold under the trade names “Palm Pilot®” (Palm, Inc.), or “Jornada®” (Hewlett-Packard), and “IBM Workpad®” (IBM) are capable of running various calendar, address book, or memo pad applications that may be used to create and store short documents. Some PDAs also have wireless-communication capability that permits them to transmit and receive data via a wireless network. The wireless connection may be used to transmit and receive many different types of information. For example, many wireless-enabled PDAs comprise a Web browser to permit the user to download and display Web pages from the Internet. Others use the wireless connection to transmit and receive e-mail. Another use of the wireless connection is to download applications to the PDA. A number of available PDAs permit users to load various applications adapted to perform specific tasks. The specific type of portable electronic device on which the transactional flash cards will be displayed is not critical.
[0038] The transactional flash cards in their printed form may also contain a playing card symbol such as suits (e.g. hearts, diamonds, clubs or spades), and a number (e.g. deuce through ace), adding a leisure function so they may also be used to play card games such as to pass time while waiting in an airport.
[0039] The transactional flash cards when displayed on the screen of an electronic device may also contain a navigational system with small icons which when selected would link the cardholder to more information stored in the electronic device's memory (e.g. games, word processor, messaging, paging, etc.). Likewise, the navigational icons may link the cardholder to the internet. The advantage of using an electronic device to store the transactional flash cards is that such a device can store a large number of such flash cards in various languages.
[0040] Where the transactional flash cards are displayed on an electronic device, the device may also contain link via internet, telephone, wireless modem, etc., to the card holder's financial institution, allowing the card holder to pay for transactions by transferring funds directly from his or her account to the account of the second party. This payment system might be accessed through an icon of the navigational system described above. The cardholder would simply type the price of the product into the electronic device (which would contain a keyboard), and the product or service would be charged to his account at the contacted financial institution. A security system could be instituted with PIN code or any other known access securing technology.
[0041] The electronic device may incorporate a built in speaker to allow transactional communication with to a second party by sound. The card may generate a voice which would speak the words for the cardholder and describe to the second party the goal and intent to perform the transaction. This would be helpful where the cardholder wishes to perform a transaction with a second party who can not read his or her own language.
[0042] The dimensions of the transactional flash cards and other design elements as boxes, rows columns, letters, pictures, and other variables as material etc. and quantities specified herein are not critical to the invention, and so may vary so long as the essential nature of the invention is retained. This is also true of the way information is displayed on the transactional flash cards or on a screen of any portable electronic device.
[0043] With reference now to the drawings, FIG. 1 shows a transactional flash card 1 which embodies the concept of the present invention in its print form on paper or any other suitable substrate. The transactional flash card 1 is used for the method described in this invention. It is noted that the possible versions of the flash card 1 of FIG. 1 are myriad (i.e. limited only by the individual goals of the particular transactions that may be featured on a flash card of the present design). The description of this single embodiment of a transactional flash card, therefore, is not intended to limit the present invention, and the transactional flash cards may be varied within the spirit of the present invention to assist the cardholder with as many transactions as is possible.
[0044] The transactional flash card 1 may, for example, serve a cardholder who is a traveler and who has as a goal of a transaction the purchase of a product from a second party which in this case is a foreign sales agent who doesn't speak the same language as the traveler. This embodiment may also apply to domestic instances where two parties speak different languages. For the foreign traveler, the transactional flash card 1 serves the cardholder in four ways:
[0045] (1) The transactional flash card 1 enables a traveler in a foreign country to purchase a product by showing this transactional flash card 1 to a foreign sales agent. The flash card 1 may be used to communicate with the sales agent in two ways: first by displaying the name of the product 2 , together with a phrase describing the first party's intent to purchase the product 3 , both of which are displayed in the language of the second party, and both of which are written in that foreign language and prominently displayed on the transactional flash card; second an image of the product 4 desired to be purchased which will clarify the traveler's choice of product even further and will help if the sales agent is not able to read the name of the product 2 in his or her own language.
[0046] (2) The transactional flash card 1 informs the traveler about the product he might want to purchase by displaying, in the traveler's language, information on the product 5 such as translation of its name and, if possible, information such as a brief description of the product, where to find the product, its price range, how to consume it, material of construction and other general and specific information. This information on the product 5 in the traveler's language is displayed much less prominently than the name of the product 2 so as not to confuse the foreign sales agent. Together with the information on the product 5 there are also small icons 6 which direct the traveler to specific categories of information without having to read the complete text. The image of the product 4 besides helping the foreign sales agent also serves the traveler as information on how the product should look.
[0047] (3) If the goal of a transaction has a payment involved as in this embodiment of the invention, a question about the price 7 in the language of the foreign sales agent, written using the characters of that language, can be displayed together with a translation of that same question into the traveler's language 8 .
[0048] (4) The transactional flash card 1 may contain a leisure feature for the traveler. The transactional flash card 1 has playing card symbols 9 displayed on its face. The traveler may, therefore, use the transactional flash card 1 to relax while traveling. The game function is, of course, not required to perform the service of assisting the traveler in purchasing a product from a sales agent he doesn't understand, but such an additional feature adds to the attractiveness and functionality of the the transactional flash card 1 . Where the transactional flash card I is provided with such a game feature, it may only be printed on one side due to the need for uniformity on the reverse side. As a result, the reverse side may be used to advertise products, web sites etc. If the game feature is omitted, a second flash card could be included on the back as well, reducing the total number of flash cards a traveler would be required to carry.
[0049] [0049]FIG. 2 displays a transnational flash card 1 on a screen 10 , for example, an LCD, LED or any other suitable screen, of a portable electronic device 11 . The transnational flash card 1 on the screen may be used in exactly the same manner as the transnational flash card 1 in print form. As such, transnational flash card 1 on the screen serves the traveler in the same three ways described above, simply using a different media. To change the transnational flash cards 1 on the screen 10 a forward or backward button 12 is pressed. These buttons are readily available on most electronic devices 11 and where a particular electronic device 11 doesn't contain these exact buttons 12 , other keys may be assigned to perform the function of changing from one transnational flash card 1 to another. If the electronic device 11 has a touch screen the buttons 12 may be provided directly on the screen. Alternatively, a screen stylus capable of interacting with a screen may perform this function. The transnational flash cards 1 could further be indexed on a content page which might aid the user in retrieving the desired flash card 1 quickly. Another commonly used feature would be a keyword search for quickly finding a particular flash card.
[0050] The only feature lost in using the electronically displayed embodiment of the transnational flash card 1 is the playing card feature 9 , since the cards are stored within the memory of the electronic device 11 and are not physically available as would be required for a card game.
[0051] Where the handheld electronic device 11 has a connection to the internet, a navigational system with links may be displayed on the transnational flash cards 1 . These links may be established with active buttons 15 on the screen which are activated when the user selects the button directly or by use of a cursor 17 . The cursor may be moved with a built in mouse 16 , or an external mouse, or a joystick etc. The buttons 15 may also establish links when touched on an interactive touch screen with a special stylus or by hand, or they may be established by voice recognition software. The links may significantly increase the functionality of the transnational flash cards 1 , for example providing access to additional information on a product or service. Through one of the special icons 15 of the navigational system the transnational flash card may establish via internet, telephone, wireless etc. a link to the card holder's financial instution. The cardholder can then type the price of the product and charge it his or her account at the financial instution. A security system may be instituted, using for example a PIN code or any other access securing technology.
[0052] The text on the cards may also be activated to establish links to sites on the internet. In a non-limiting example, the name of an ingredient could be active, linking the user to a site that might explain the ingredient further to and inform the user where it might be purchased. In this way the traveler may also have access to an internet or internal game function. This would replace the leisure function of the playing card symbols 9 available in the transactional flash cards 1 in the printed form.
[0053] In yet a further embodiment, the electronic device 9 might have a built in speaker 13 which, in combination with the memory of the electronic device, could say the name of the product or service desired to be purchased to the foreign sales agent when a button 14 is pressed.
[0054] [0054]FIG. 3 shows a special transactional flash card 18 which displays the question about the price of the product 7 in the foreign language written with the characters of that foreign language prominently displayed. This flash card 18 displays the same question as on the transactional flash of FIG. 1, but in a more emphasized fashion. Such an embodiment be useful in the situation where there are no price tags attached to a product or service. As with the transactional flash card 1 of FIG. 1, a translation of the question about the price 8 also appears in smaller type in the traveler's language. Additionally included is a question in the second party's language, in this case that of a foreign sales agent. Such language could inquire whether credit cards are accepted 18 , using the icons of common credit cards, or whether traveler's checks are accepted 19 together with icon of common traveler's check companies.
[0055] [0055]FIG. 4 shows the special transactional flash card 18 of FIG. 3 with two additional erasable surfaces 21 and 23 . The surface 21 is provided so the sales agent may hand write his offer price and the traveler can erase that price if he would like to suggest a lower price. In this way a clear communication about the price is possible in the case where there are no price tags attached to a product, the common sign language dealing with numbers fails, or where the user simply would like to negotiate the price. Within the erasable surface 21 there is also a space 22 where the cardholder may enter and erase the exchange rate. The second erasable surface 23 may contain a question such as “do you deliver or ship?” followed by the words “delivery/shipping address.” On the surface 23 the traveler can enter his travel or home address in the case in which the first question is answered in the affirmative.
[0056] [0056]FIG. 5 displays the transactional flash card 18 of FIG. 3, further displaying the flash card on a screen 10 as for example an LCD, LED or any other suitable screen of any portable electronic device 11 . The special transactional flash card 18 displayed on a screen 10 has the same feature as the special transactional flash card 18 in print form displayed in FIG. 3. In this embodiment, next to the question about the price of the product 7 in the foreign language, a translation of that question 8 in the traveler's language is displayed. As described in the text on FIG. 2 this embodiment may provide links to internet sites and search engines etc. from which the user may obtain additional information on the product or service.
[0057] [0057]FIG. 6 shows the transactional flash card 18 of FIG. 3 being displayed on the digital screen 10 of a hand held electronic device 11 , where the question about shipping and delivery is displayed on the screen. In the electronic version, the address may be entered by keyboard, or by special stylus that interacts with the screen, or by any other means known in the art.
[0058] [0058]FIG. 7 shows the transactional flash card 18 of FIG. 5 where the electronic device further comprises a calculator 25 . Such a calculator function may allow the traveler to display the price of the product to more easily communicate with the sales agent or to compute the price into her/his native currency.
[0059] [0059]FIG. 8 shows the transactional flash card 18 of FIG. 5 further comprising a currency converter. In the embodiment shown, three buttons 26 may be used to perform this function. The user would press “forn” and enter the price in foreign currency, then the user would presses “xcha” and enter the exchange rate, which could default to the last entered rate. Pressing “hom” would activate a programmed computation, internal to the electronic device's memory, to produce the price in the user's own currency. Any other acronyms than “forn”, “xcha” or “hom” could be used without changing the character of this function. Further, if the electronic device has access to the internet, a link could be used to connect to a financial service that would automatically update the exchange rate and automatically use it in the above computation.
[0060] [0060]FIG. 9 shows the transactional flash card 18 of FIG. 5 further comprising an interactive surface 27 where the cardholder or the second party may enter transactional information with an interactive stylus 28 , and which information will be displayed in an area of the flash card 29 . The electronic device 11 may further comprise a microphone 30 and voice recognition software to allow the user or second party to speak into the electronic device and display the words or their translations in the area 29 .
[0061] Accordingly, it should be understood that the embodiment herein is merely illustrative of the principles of the invention. Various other modifications may be made by those skilled in the art which will embody the principles of the invention and fall within the spirit and the scope thereof.
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A method for performing a transaction without the use of spoken communication is disclosed. The method consists of providing at least one transactional flash card having information about the transaction and the transaction goal displayed on the card in text understandable to the user and different text understandable to the party from whom the user wishes to purchase goods or services. The method may include displaying such a flash card in printed form, or on a personal electronic device. The method may further include providing flash cards having inquiries about price, payment methods, or shipping terms. Also disclosed are transactional flash cards used with the method.
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This is a continuation-in-part of application Ser. No. 09/004,362, filed Jan. 8, 1998.
BACKGROUND OF THE INVENTION
Wheelsets for railroad cars are usually comprised of an axle and two wheels. The wheels are pressed on to the axle shaft and are rigidly mounted so that both wheels turn exactly the same degree of rotation during operation. The wheelset assembly may be supported by journal bearings outboard of each wheel or the bearings may be located inboard of the wheels. The rigid assembly of the wheels on the axle and the lack of independent rotation of the wheels is the cause of slippage on the rail when the wheelset operates in curved sections of track. This slippage causes wear on the wheel treads and rails and is a prime cause of corrective maintenance on both the wheels and the track.
Efforts have been made to overcome the problems associated with the rigid assembly of conventional wheelsets by placing bearings between the axle and the wheel on at least one end of the axle to permit differential speeds of rotation of the wheels at opposite ends of the axle. In such cases, a hub is located on at least one end of the axle and a wheel is mounted on the hub or on the axle and its rotation with respect to the axle is facilitated by a bearing assembly. As discussed hereafter, electrical continuity from the two rails through the wheels and the axle is necessary for operation of signal devices or the like. This electrical continuity was established with the conventional railroad wheelsets wherein the wheels were rigidly fixed through opposite ends of the axle. However, with the advent of one of the wheels being mounted on the axle by means of a bearing assembly, the electrical continuity between the wheels was less than perfect. With the advent of non-metallic bearings, the electrical continuity was not possible.
A typical signal device for a road crossing, for example which utilizes a crossing arm, flashing lights, and the like, derives electrical energy from any conventional source. A low voltage is imposed on a given dedicated length of rail on opposite sides of the signal, with the opposite rail being electrically connected to the signal whereupon the signal circuit is closed when the wheel assembly of a train initially moves onto the dedicated length of rail. The circuit is completed between the opposite rails through the wheels and axle of the train's wheel assemblies which allow the flow of energy therethrough to electrically connect the opposite rails.
Even when a differential action wheelset is used, an adverse situation arises wherein, upon beginning motion, one of the independent wheels moves in one direction and the other wheel on the axle moves in the opposite direction in a pivoting effect. That is because when an axle is provided with one or more independently rotatable wheels, it is possible for the axle to rotate about its vertical centerline if one of the wheels rotates in one direction and the other wheel rotates in the opposite direction. If the axle with the independently rotatable wheels is mounted in a short wheelbase two-axle truck, it may be possible for the two wheels on one side of the truck to move in one direction, while the two wheels on the other side of the truck rotate in the opposite direction. This action may result in derailing the truck and will be more pronounced and prevalent in a short wheelbase two-axle truck than in a long wheelbase two-axle truck.
Field testing by the American Association of Railroads (described in ASME Paper No. 7-5, dated Sep. 12-15, 1988) indicates that in certain situations it is desirable to have the wheelset in the leading axle position of a multi-axle truck be equipped with non-independent wheel rotation, and the wheelset in the trailing axle position equipped with independently rotating wheels. The problem in such an arrangement is that the leading axle wheelset when the railroad car is operating in one direction is the trailing axle wheelset when the railroad car operates in the opposite direction.
It is, therefore, a principal object of this invention to provide a railroad car wheelset with independently rotating wheels in which the differential action is made inoperable upon stopping and at lower speeds, and when the differential action is automatically resumed when the wheel rotation reaches a predetermined operational speed.
A further object of this invention to provide a railroad wheelset with independent rotation of wheels with respect to each other which will consistently retain the electrical continuity between the opposite wheels and the rails upon which they are supported.
A still further object of this invention is to provide a wheelset with independent rotation of the wheels with respect to each other which can be used in existing truck designs without modification to the truck structures or the braking system.
A still further object of this invention is to provide a railroad wheelset which requires no additional maintenance than conventional rigid wheelsets after installation and during service.
A still further object of this invention is to provide a railroad wheelset with independently rotating wheels in which the differential action is made available with no decrease in safety or reliability.
A still further object of this invention is to provide a railroad car wheelset with independent wheel rotation which can be economically manufactured and applied to railroad cars of all types.
A still further object of this invention is to provide a railroad car wheelset with independent wheel rotation wherein the bearings for the independently rotatable wheel is comprised of a lubricating coating.
A still further object of this invention is to provide the alternate capability of operating a wheelset either as a fixed-wheel wheelset in one direction and as an independently rotatable wheel wheelset in the opposite direction.
A still further object of this invention is to permit the alternate capability to be achieved using a minimum of special parts and a maximum of common parts.
These and other objects will be apparent to those skilled in the art.
SUMMARY OF THE INVENTION
The railroad car wheelset of the present invention includes an axle with one wheel rigidly attached as in conventional railroad practice. This wheel is permitted to rotate by means of journal bearings either on the extreme ends of the axle or inboard of each wheel location. At the location of the other wheel, the axle is provided with a smooth surface and a self-lubricating bearing is provided. The axle shaft is provided with a boss or other means of preventing the independently rotating wheel from migrating laterally out of proper alignment. A self-lubricating thrust bearing is located between this boss and the side of the wheel to eliminate any possible galling between the two moving surfaces. A removable retainer plate is located on the other side of the independently rotating wheel to prevent the wheel from moving laterally in that direction. Adjacent the removable retainer plate is an electrical contactor which can conduct an electrical current from the wheel to the axle shaft, to permit the wheelset to properly operate railway signals or other systems dependent on electrical continuity. In lieu of the self-lubricated bearings, the bearings can be comprised of a lubricant coating permanently bonded to the bearing surface of the hub adjacent the independently rotatable wheel.
An axle with two wheels in which one wheel may rotate independently of the other may be pivoted about its vertical centerline in the event one of the wheels rotates in one direction and the other wheels rotate in the opposite direction. The railroad car wheelset of the present invention may include a means of locking the independently rotatable wheel to the axle rigidly when the rotation of the wheel ceases, or when the wheel is rotated slowly. This locking means automatically releases when the wheel and axle reach a predetermined speed of rotation, at which time the differential action of the independently rotating wheel is again permitted.
An alternate form of the present invention is provided for situations in which one of the wheelsets in a truck is desired to be of the fixed-wheel type in one direction and also is desired to function as an independently rotatable wheel wheelset in the opposite direction. The railroad car wheelset of the present invention includes a means of locking the independently rotatable wheel to the axle rigidly when the rotation of the wheel is in one direction, and automatically unlocking the independently rotatable wheel from the axle when the rotation of the wheel is in the opposite direction. The proper arrangement of these wheelsets in the truck frame permits the leading axle to automatically operate as a fixed-wheel wheelset and the trailing axle to operate as an independently rotatable wheel wheelset regardless of which direction the railcar is moving.
Thus, the independently rotatable wheel is locked to the axle automatically in one direction and permits the independent rotation of the wheel automatically when the rotation is in the opposite direction. By arranging the wheelsets 180° from each other in the truck frame (as shown in FIG. 14), the trailing axle is always equipped with independently rotating wheels and the leading axle is always functioning as a conventional axle with two fixed and non-independently rotating wheels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a conventional prior art railroad wheelset;
FIG. 2 is an elevational view of the preferred embodiment of the railway wheelset of the prior application Ser. No. 09/004,362;
FIG. 3 is an exploded view of the components within the line 4--4 of FIG. 2;
FIG. 4 is an enlarged scale view of the components contained within the line 4--4 of FIG. 2;
FIG. 5 is a transverse sectional view of the structure of FIG. 4;
FIG. 6 is an elevational view of the structure of FIG. 4 as viewed from the left-hand side of FIG. 4;
FIG. 7 is an elevational view similar to that of FIG. 2 but shows the preferred embodiment of this invention;
FIG. 8 is a large scale partial elevational view taken on line 8--8 of FIG. 7;
FIG. 9 is an elevational view looking at the inside of the independently rotatable wheel when it is stopped or operating at low speed, showing the upper rotatable latches engaging the toothed integral axle retainer hub;
FIG. 10 is an elevational view looking at the inside of the independently rotatable wheel when it is rotating above a predetermined speed, showing that the rotatable latches have been swung outwardly by centrifugal force and that none of the rotatable latches engage the toothed integral axle retainer, and that the wheel is again able to rotate independently of the axle;
FIG. 11 is a sectional view taken on line 11--11 of FIG. 9;
FIG. 12 is an elevational view looking at the inside of the alternate form of the independently rotatable wheel when it is operating in a clockwise manner;
FIG. 13 is an elevational view looking at the inside of the alternate form of the independently rotatable wheel when it is operating in a counter-clockwise manner; and
FIG. 14 is a plan view showing the positions of the locking devices of FIGS. 12 and 13 of the independently rotatable wheels as the axles are mounted in a truck frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The conventional prior art wheelset 10 is shown in FIG. 1 and is comprised of the horizontal axle 12 with wheels 14A and 14B adjacent its opposite ends. The wheels 14A and 14B are each rigidly secured to axle 12 by being pressed on the axle up against bosses 18, respectively.
The preferred embodiment of the invention of application Ser. No. 08/004,362 is shown in FIGS. 2, 3, 4, 5 and 6. With reference to FIG. 2, the right-hand wheel 14B is affixed to the axle 12 in the same manner that wheel 14B was secured to the axle 12 in FIG. 1. However, at the other end of axle 12 in FIG. 2, a hub 20 is integral with the axle 12. Hub 20 has an annular flange 22 of increased diameter. With reference to FIG. 3, hub 20 has a cylindrical bearing surface 24 and a vertical bearing surface 26 adjacent thereto. A vertical circular face 28 on hub 20 has a plurality of threaded apertures 30.
A cylindrical flat planar thrust bearing 32 is mounted on bearing surface 24 and when assembled, bears against bearing surface 26. A cylindrical sleeve bearing 34 is then mounted on bearing surface 24 adjacent the thrust bearing 32. In assembly, the wheel 14A which has a large diameter center bore 36 is slidably mounted on the sleeve bearing 34 (FIG. 5). The center bore 36 of wheel 14A has an annular groove 38 on the outboard side thereof. A circular metal conductor plate 40 with the center opening 42 and a plurality of apertures 44 (equal in number and size to apertures 30 in face 38 of hub 20) is mounted within annular groove 38. A retainer plate 46 (FIGS. 3 and 5) is also mounted in annular groove 38. Retainer plate 46 has a center opening 48 and a plurality of apertures 50. Conventional threaded bolts 52 extend through the registering apertures 50 (in retainer plate 46); 44 (in conductor plate 40); and 30 (in hub 20).
It should be noted (FIG. 4) that a space 54 exists between the bearing surface 24 of hub 20 and the center opening or bore 36 in wheel 14A. This space is normally occupied by sleeve bearing 34. However, in an modified form of the invention, the space 54 can be filled with a lubricating coating (not shown), in lieu of the sleeve bearing 34. Wheel bore 36 can be adjusted in diameter as required.
There are available in the industry synergistic coatings (e.g., Hi-T-Lube®) which become an integral part of the top layer of a base metal rather than merely a surface cover. This lubricating coating has a hard interface metal layer adjacent the base metal; a semi-soft, compressible metal layer adjacent the base metal; a semi-soft, compressible metal layer adjacent the hard interface layer; a hard, thin oxide layer adjacent the compressible layer; and an outer malleable, dry lubricant layer on the outer surface of the thin oxide layer. This lubricating layer can resist wear of the base metal by up to 15 times under cryogenic conditions. This and other lubricating coatings in the industry in environments from room temperature up to 1000 degrees Fahrenheit can withstand high applied loads at relatively high speeds and frequent reversal in direction. Under such conditions, these products performed effectively for long periods of time where other lubricants and combinations of materials failed in a relatively short period of time. The thickness of the coating (and the radial height of space 54) can be in the order of 0.0003 inches-0.001 inches in thickness and has a coefficient of friction in the range of 0.03 and can withstand high compression loads in excess of 150,000 psi. Hardness of available material is up to an equivalent of Rc 55.-R c 85. These materials are not, per se, a part of this invention and have not been previously used in the application of bearings for railway wheelsets but the present invention makes provision for this technology.
It should be understood that the space 54 normally occupied by a bearing sleeve 34 could be occupied by the lubricating coating described heretofore instead of the sleeve bearing 34.
As previously indicated, when the axle is provided with one or more independently rotatable wheels, it is possible for the axle to rotate about its vertical centerline if one of the wheels rotates in one direction and the other wheel rotates in the opposite direction. If the axle with the independently rotatable wheels is mounted in a short wheelbase two-axle truck, it may be possible for the two wheels on one side of the truck to move in one direction, while the two wheels on the other side of the truck rotate in the opposite direction. This action may result in derailing the truck and will be more pronounced and prevalent in a short wheelbase two-axle truck than in a long wheelbase two-axle truck.
To prevent the independently rotatable wheel from rotating in the opposite direction from the other wheel, an automatic locking means is provided to prevent the rotation of the independently rotatable wheel when stopped or when operating at low speeds. When the rotation of the locked independently rotatable wheel reaches a predetermined rotational speed, the locking means automatically releases and the differential action can again be utilized.
With references to FIGS. 7-11, an independently rotatable wheel 14C is shown. The axle retainer hub 56 has been modified to provide engagement teeth 58 for releasable engagement with a plurality of pivoting latches 60 which are equipped with self-lubricating bearings 62 mounted on pivot pins 64. Each latch 60 has engagement teeth 61 adapted to nest at times between teeth 58 on hub 56. Each pivot pin 64 is equipped with self-lubricating thrust bearing latch retainers 66 which are in turn secured by means of stainless steel snap rings 68 or equivalent. Each pivot pin 64 is securely inserted into a latch boss 70 made integral with the wheel. Also integral with and offset from the wheel are a plurality of latch stops 72 which restrict the travel of the pivoting latches 60 from excessive outward travel.
FIG. 9 shows the configuration of the rotatable latch 60 when acted upon by gravity when the independently rotatable wheel 14C is rotating slowly or is at rest in a motionless state. FIG. 10 shows the position of the rotatable latches 60 when acted upon by centrifugal force and restrained from further outward motion by integral latch stops 72.
It will be understood that alternative automatically operating latching mechanisms and restraints may be employed as mechanical equivalents without departing from the spirit of the invention.
It is therefore seen that the wheelsets of this invention can be easily assembled and can easily create a wheelset with a single rigid wheel at one end of the axle and an independently rotatable wheel at the other end of the axle. The electrical continuity through the wheelset is guaranteed by the presence of conductor plate 40 which can maintain this electrical continuity without having to pass through the wheel bearings themselves. With reference to FIG. 2, the electrical continuity between the rails upon which wheels 14A and 14B are mounted is completed from the rail under wheel 14B through wheel 14B and thence through axle 12, through conductor plate 40, and into wheel 14A to the opposite rail.
The foregoing structure of FIGS. 7-11 provide means for locking the independently rotatable wheel to the axle rigidly when the rotation of the wheel ceases, or when the wheel is rotated slowly. This locking means automatically releases when the wheel and axle reach a predetermined speed of rotation, at which time the differential action of the independently rotating wheel is again permitted. A typical speed at which this takes place is 5-10 mph or a wheel speed of 50-100 rpms. This is accomplished by the axle retainer hub 56 being provided with teeth 58 for releasable engagement by the rotatable latches 60 pivotally mounted on pivot pins 64, said rotatable latches engaging the toothed retainer hub 36 by gravitational action when the wheel 14C is not rotating or rotating at slow speed, and the rotatable latches 60 disengaging teeth 58 due to centrifugal force when the wheel 14C rotates beyond a predetermined speed.
The alternate embodiment of the present invention is shown in FIGS. 12, 13 and 14. With reference to FIGS. 12, 13 and 14, the wheel 14C is capable of independent rotation with respect to axle 12, as previously described. The axle retainer hub 56A has been modified to provide engagement teeth 58A, each with a near-radial bearing surface on the clockwise side 59, and a sloping surface 59A on the counter-clockwise side. These engagement teeth 58A are for releaseable engagement with a plurality of pivoting double-arm latches 60A which are equipped with self-lubricating bearings 62 mounted on pivot pins 64. (FIG. 8). Each latch has an engagement tooth 61A adapted to nest at times between teeth 58A on hub 56A. As with the structure of FIGS. 9-11, each pivot pin 64 is equipped with self-lubricating thrust bearing latch retainers 66 which are in turn secured by means of stainless steel snap rings 68 or equivalent. Each pivot pin 64 is securely inserted into a latch boss 70 made integral with the wheel. Also integral with and offset from the wheel are a plurality of latch stops 72 which restrict the travel of the pivoting latches 60A from excessive outward travel. Centrifugal force acting on the weighted end 60B of the pivoting latches 60A tends to keep the engagement teeth 61A of these latches in proper position with respect to the axle retainer hub engagement teeth 58A, when the wheel rotates, or, when the wheel is stopped or operating at very slow speeds, gravitational force acting on the weighted ends 60B of the double-arm latches 60A tends to keep the engagement teeth 61A of these latches in engaged position. In FIG. 12, it is to be noted that the arrow indicating direction of rotation relates to the rotation of the axle 12 and axle retainer hub 56A with respect to possible rotation of the independently rotatable wheel 14C and not to the rotation of the wheel with respect to a non-rotating axle. The wheel 14C cannot rotate in a counter-clockwise manner with respect to the axle as shown in FIG. 12.
FIG. 13 shows the above components in play when rotation is in the opposite direction. Although the centrifugal and gravitational forces tend to keep the engagement teeth 61A of the pivoting double-arm latches 56A in proper position for engagement with the teeth 58A of the toothed axle retainer hub 56A, the sloping surface 59A of the teeth of the axle retainer hub prevent the proper engagement of the teeth and permit the wheel to rotate independently in the clockwise direction. Again, in FIG. 13, it is to be noted that the arrow indicating direction of rotation relates to the rotation of axle 12 and the axle retainer hub 56A with respect to possible rotation of the independently rotatable wheel 14C, and not to the rotation of the wheel with respect to a non-rotating axle. The wheel 14C can rotate in a clockwise manner with respect to the axle as shown in FIG. 13. Since the differential rotation of one wheel with respect to the other wheel of a wheelset is not expected to ever exceed 15 RPM, wear to the teeth 61A of the pivoting double-arm latches 60A or to the toothed axle retainer hub is expected to be minimal.
FIG. 14 is a diagram showing placement of the independently rotatable wheels and locking mechanisms for the wheelsets in a railroad car truck 74.
The foregoing structure of FIGS. 12-14 provide means for automatically locking the independently rotatable wheel 14C to the axle 12 rigidly in one direction, and automatically disengaging the independently rotatable wheel from the axle when rotation is in the opposite direction. This is accomplished by the axle retainer hub 56A being provided with teeth 58A with a near-radial bearing surface 59 on one side to resist rotation toward that surface, and a sloping bearing surface 59A on the other side to permit rotation toward that surface. Pivotable latches 60A with teeth 61A engage the teeth 58A of the axle retainer hub, urged by centrifugal and gravitation forces, but the near-radial and sloping surfaces either augment or prevent the locking action. The locking and disengaging action is automatic at all times. FIG. 12 shows that the rotatable latches of this alternate design have been rotated by centrifugal force and that the teeth of these latches are in contact with the near-radial sides of the teeth of the toothed integral axle retainer, and that the wheel is not free to rotate in this direction. FIG. 13 shows that the rotatable latches of this alternate design have been rotated by centrifugal force but that the teeth of these latches are in contact with the sloping sides of the teeth of the toothed integral axle retainer, and that the wheel is free to rotate in this direction.
It is therefore seen that this invention will achieve at least all of its stated objectives.
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A railroad car wheelset has an axle with one wheel rigidly attached as in conventional railroad practice. This wheel is permitted to rotate by journal bearings. At the other wheel, the axle is provided with a smooth surface and a self-lubricating bearing is provided as a part of a hub on the axle. The axle is provided with a boss for preventing the independently rotating wheel from migrating laterally out of proper alignment. A bearing is located between this boss and the side of the wheel. A removable retainer plate is located on the other side of the independently rotating wheel. Adjacent the removable retainer plate is an electrical contactor. The bearings can be comprised of a lubricant coating permanently bonded to the bearing surface of the hub. Latch elements are pivotally secured to the other wheel and engagable with locking elements operatively secured to the axle. A second wheelset has an independently rotatable wheel locked to the axle automatically in one direction.
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FIELD OF THE INVENTION
This invention relates to the field of automotive accessories, in particular to brake covers.
BACKGROUND OF THE INVENTION
Typical automotive braking systems use brake calipers to engage the rotor when braking is desired. Most automotive braking systems consist of floating or sliding single or double piston type calipers. In some high performance vehicles, the vehicles have high performance braking systems utilizing four piston aluminum fixed brake calipers. Various aftermarket kits are available to allow automotive enthusiasts to install high performance braking systems in their vehicles.
However, many automotive enthusiasts do not need the high performance braking system provided by the aftermarket high performance braking kits, but are only interested in the aesthetics provided by the installation of four piston calipers, particularly when used with aftermarket high performance aluminum wheels. Therefore it would be advantageous to provide a brake caliper cover for typical automotive braking systems which allows the braking systems to exude the aesthetic appeal of a high performance brake caliper, without the need to install the costly high performance braking systems.
Brake calipers covers are currently available to enhance various visual aspects and useful aspects of an automotive braking system. U.S. Pat. No. 7,144,142 discloses an illuminated cover for a brake caliper. Brake calipers covers, such as ones disclosed in U.S. Patent Application Publication 2004/0074716, are used to reduce the build up of brake dust. U.S. Patent Application Publication 2009/0321198 discloses brake caliper covers with vent openings to provide beneficial dynamics such as cooling the brake caliper mechanisms.
The present inventor has recognized the need for a brake caliper cover with increased stability.
The present inventor has recognized the need for a brake caliper cover with minimal movement once installed.
The present inventor has recognized the need for a brake caliper cover which is easy to install and remove.
The present inventor has recognized the need for a brake caliper cover which does not require modification to the existing brake assembly for installation.
SUMMARY OF THE INVENTION
A brake caliper cover system for at least partially enclosing an existing brake caliper assembly in a vehicle is disclosed. The brake caliper cover system has a front cover and a back cover. The front cover and back cover are disposed on the front and back sides of a brake caliper assembly. The front cover and back cover are fastened together and secured to the brake caliper assembly.
In some embodiments the front cover has a cushioning layer on the inner surface to minimize vibration and movement of the front cover over the front side of the brake caliper assembly. The back cover may also include a layer of foam on an inner surface for the same purpose.
In some embodiments each cover has an inner surface facing the brake disc configured to enclose the contours of the brake caliper assembly such that each cover can be disposed securely over the brake caliper assembly. The covers are attached to a fixed portion of the caliper. The covers when attached to the fixed portion allow a moving part of the caliper, such as the hydraulic piston(s), to move along shafts within a spaced defined by the cover.
Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a brake caliper assembly and the brake disc.
FIG. 2 is a perspective view of the brake caliper assembly of FIG. 1 with one exemplary embodiment of the brake caliper cover system.
FIG. 3 is an exploded view of the brake caliper cover system and the brake caliper assembly.
FIG. 4 is a back perspective view of the brake caliper covers on the brake disc caliper with the brake disk removed for clarity.
FIG. 5 is a perspective view of the back caliper cover engaging with the brake caliper assembly.
FIG. 6 is a perspective view of the back side of the brake caliper assembly with the back caliper cover.
FIG. 7 is a perspective view of the brake caliper assembly with the back caliper cover and the brake disc removed for clarity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.
FIG. 1 illustrates a front perspective view of a conventional brake caliper assembly 10 in an automobile. The brake caliper assembly 10 includes a caliper housing 20 disposed over a bracket member 30 , for receiving brake pads 40 . Piston housing 50 ( FIG. 7 ) receives hydraulic fluid for actuating hydraulic cylinders (not shown) which compress the pair of brake pads 40 against the brake disc 60 when braking is desired. In some embodiments, the brake caliper assembly may be that shown in U.S. Pat. No. 4,775,034, which is incorporated by reference to the extent not inconsistent with the present description. It will further be recognized that in some embodiments, the brake caliper assembly may be any such brake assembly known in the art.
As illustrated in FIG. 2 , illustrates a front caliper cover 70 of the brake caliper cover system 65 is disposed over the front side of the brake caliper assembly 10 . The front caliper cover 70 encloses the front side of the caliper housing and the front brake bracket, and extends to enclose, the spine region 25 ( FIG. 1 ) of the caliper housing 20 and the spine region 35 of the brake bracket. The caliper cover system has an upper region 75 above, and a lower region 76 below, the spine regions 25 , 35 . The upper and lower regions 75 , 76 of the caliper cover system has shafts or bosses 77 ( FIG. 3 ) for receiving bolts 78 . The bosses 77 can be molded into the cover 70 . The bosses provides a holding feature for the bolts. As illustrated in FIG. 2 , two bolts are disposed at the upper region 75 , and two bolts are disposed at the lower region 76 to fasten the front and back caliper covers together. The top of the shafts 77 are recessed to receive the top of the bolt such that the top of the bolts do not protrude from the cover.
FIG. 3 illustrates an exploded view of the brake caliper cover system and the brake caliper assembly. The back brake caliper cover 80 of the brake caliper cover system 65 has threaded shafts or bosses 88 for receiving the bolts 78 . The bosses 88 can be molded into the cover 80 . In some embodiments, bosses are not threaded and instead threads are created when the receiving bolts 78 are screwed into the bosses. As illustrated in FIGS. 3 and 4 , the back caliper cover 80 does not enclose the piston housing. The back caliper cover 80 has a U-shaped contour 81 which conforms around the piston housing 50 . In some embodiments, the back of the cover 80 as well as the cover 70 will be of other shapes to conform to the various shapes of difference styles of caliper design. As illustrated in FIG. 5 , the back caliper cover 80 has an upper 82 and lower 84 lip extension which allows the back cover to fit over a portion of the spine region 25 of the caliper housing. In some embodiments, the back cover 80 has upper 86 and lower 89 tabs which protrude into, and engage with, the region above and below the back brake bracket ( FIG. 6 ).
Without wishing to be bound by any particular theory, it is believed that the back caliper cover 80 provides mounting support for the front caliper cover 70 . Fastening the front caliper cover to the back caliper cover allows the front caliper cover to be secure against the front side of the caliper housing and the front side of the brake bracket. Upper and lower lips 82 , 84 , which extend about the top and bottom of the piston housing ( FIG. 5 ) and upper and lower tabs 86 , 89 , which protrude into the region above and below the back brake bracket, minimizes the movement of the back cover, and accordingly the movement of the front caliper cover, in both a vertical and horizontal direction. The back caliper cover 80 has portions with a recessed perimeter which forms a recessed edge 85 ( FIG. 5 ) to allow portions of the front cover 70 to receivingly engage with the back caliper cover. The covers are attached to a fixed portion of the caliper. The covers, when attached to the fixed portion, allow a moving part of the caliper, such as the hydraulic piston(s), to move along shafts within a spaced defined by the cover. This advantageous because as brake pads wear the position of the caliper moves to account for the fact that the brake pads have friction areas that are reduced compared to their new condition. In this way, the caliper cover not interfere with the braking operation of the caliper.
FIG. 7 illustrates a perspective view of the inner surface of the front brake cover 70 in position over the front brake bracket. As illustrated in FIG. 7 , the inner surface of front brake cover is configured to at least cover, and/or to conform to the shape of the front brake bracket and the front brake caliper housing. The front and back brake covers extend above and below the brake bracket such that a portion of the brake disc is also covered by the front and back brake caliper covers. The front brake cover is configured to provide aesthetic appeal to an observer. The inner surface of the front caliper cover can comprise a layer 90 for cushioning the contact between the brake caliper assembly and the caliper cover. The cushioning layer may be a foam layer, or any other suitable material. The cushioning layer can assist in minimizing vibration and/or movement of the brake caliper cover against the brake caliper assembly. The foam layer may be disposed on a portion of the inner surface of the front brake caliper cover as illustrated in FIG. 7 , or may be disposed such that the entire inner surface, including the surface enclosing the spine of the brake bracket and the spine of the caliper housing, of the front brake caliper is covered. Alternatively, only the front inner surface of the brake caliper cover may be covered in foam. The foam layer can be made of any suitable foam material which is preferably resistant to wear and tear, and deterioration due to exposure to braking conditions, including heat. The foam layer can be secured to the inner surface of the front brake cover using an adhesive. The inner surface of the back brake cover can also have a cushioning layer over the entire inner surface, or a portion thereof.
From the foregoing, it will be observed that numerous variations and is modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred.
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A brake caliper cover system for existing brake caliper assembly in a vehicle. The brake caliper cover system has a front cover and a back cover. The front cover and back cover are disposed on the front and back sides of a brake caliper assembly, respectively. The front cover and back cover are fastened together about the brake caliper assembly.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to logging-while-drilling ("LWD") tools and to methods of operating logging while drilling. In another aspect, the present invention relates to LWD tools having turbine blades which, when driven by the circulating well fluid provides electrical power to the tool, and to a method of operating such a tool. In even another aspect, the present invention relates to LWD tools having a deflector for deflecting a portion of the circulating well fluid away from the turbine blades, and to a method of operating such a tool.
2. Description of the Related Art
Logging While Drilling Tools (LWD) are used to provide real-time quantitative analysis of sub-surface formations during the actual drilling operation. Typically, these quantitative measurements include: formation resistivity, neutron and density porosity, and acoustic travel time of the formations of interest. Due to the fact that the LWD tool string is an integral part of the bottom hole assembly, it is impractical to connect an umbilical (i.e. wireline) from the surface to provide the electrical power required by the various LWD components.
In the prior art, there have been primarily two sources of electrical power for downhole LWD tools. These include: 1) lithium batteries; and 2) downhole turbine/alternator power supplies. Lithium batteries have been used reliably in both LWD and Measurement While Drilling (MWD) applications for quite some time. The major shortcomings of the lithium batteries are: 1) the batteries have a finite life; 2) they have a limited maximum current rating; 3) once the batteries are "used-up", there are difficulties associated with the proper disposal of the depleted cells; and 4) the batteries tend to be a safety concern if mishandled. Due to the relatively large power requirements of modern LWD tools, turbine/alternator power supplies are commonly used. In turbine/alternator power supplies, mechanical power is extracted from the flow of drilling fluid by means of a fluidic turbine. The rotational output of the turbine is coupled to the input of a permanent magnet alternator which, by means of electronic regulation, is used to power the LWD tool string. Turbine/alternator power supplies have the advantage of providing relatively large amounts of electrical power. This is due to the fact that the flow of drilling fluid provides an extremely large amount of mechanical power available for conversion. Also, turbine/alternator power supplies are able to provide electrical power theoretically for as long as the drilling fluid is circulating, thereby extending the downhole life of the LWD tool string.
There have been numerous shortcomings with turbine/alternator power supplies. Due to the fact that the turbine is extracting mechanical power directly from the drilling fluid flow, a large amount of erosion is typically encountered on and adjacent to the turbine's rotating elements. Depending on the LWD tool size (i.e. outside diameter) a wide range of drilling fluid flow must be accommodated. In order to accommodate the wide flow range typically encountered in LWD tools, several turbine blade arrangements must be adaptable to the turbine/alternator power supply. This obviously adds overall system cost and the possibility of human error in appropriately selecting the turbine blade arrangement required for a given drilling (i.e. flow rate) condition. Also, because the turbine blades are positioned directly in the path of the drilling fluid flow, they are extremely susceptible to jamming or plugging by debris such as pipe scale or "lost circulation materials" commonly encountered in drilling environments.
As an additional shortcoming, turbines of commonly utilized downhole turbine/alternator power supplies are outfitted with blades which occupy the entire flow annulus. These "full-bore" turbines are highly susceptible to plugging or jamming by debris present in the flow. In an effort to reduce the risk of plugging in existing turbines, the blades themselves are designed with large clearances, both radially at the blade tips of the turbine rotor and axially between the turbine stator and rotor, to allow the passage of debris. As a result of these large blade clearances, the turbines themselves are fairly inefficient and extremely susceptible to erosion due to the formation of vorticity.
There is a need in the art for an improved LWD tool/turbine arrangement.
There is another need in the art for a turbine arrangement that is less susceptible to jamming or plugging by debris such as pipe scale or "lost circulation materials" commonly encountered in drilling environments.
There is even another need in the art for an LWD tool turbine arrangement having improved efficiency over prior art LWD tool turbine arrangements.
These and other needs in the art will become apparent to those of skill in the art upon review of this patent specification, including its claims and drawings.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide for an improved LWD tool/turbine arrangement.
It is another object of the present invention to provide for a turbine arrangement that is less susceptible to jamming or plugging by debris such as pipe scale or "lost circulation materials" commonly encountered in drilling environments.
It is even another object of the present invention to provide for an LWD tool turbine arrangement having improved efficiency over prior art LWD tool turbine arrangements.
These and other objects of the present invention will become apparent to those of skill in the art upon review of this patent specification, including its claims and drawings.
According to one embodiment of the present invention there is provided a logging-while-drilling tool for use in a wellbore. In a drilling operation, a well fluid is circulated into the wellbore through the hollow drill string. The tool generally includes an elongated tool body adapted to be positioned within the hollow drill string and sized to form an annulus between the drilling string and the tool body. The tool also includes a drilling string coupling attached to the tool body for coupling the tool to the drill string. The tool further includes measurement electronics attached to the tool body for gathering wellbore information, such as formation resistivity, neutron and density porosity, and acoustic travel time of the formations of interest. The tool even further includes an alternator attached to the tool body for generating electrical power for the measurement electronics. The tool still further includes a turbine attached to the tool body, and having blades adapted to be driven by the well fluid being circulated into the wellbore through the hollow drill string. The tool finally includes, a deflector positioned adjacent the turbine blades, and adapted to deflect a portion of the well fluid away from the turbine blades into the annulus.
According to another embodiment of the present invention there is provided a method of operating a logging-while-drilling tool positioned within a hollow drilling string positioned within a wellbore. The tool generally includes measurement electronics, an alternator for providing electrical power to the electronics, and a turbine for driving the alternator. The method includes pumping a well fluid into the hollow drilling string into contact with the blades of the turbine and drive the alternator and generate electrical power for the electronics. The method further includes deflecting a portion of the injected well fluid away from the turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a typical drilling operating showing drilling rig 42 and logging while drilling ("LWD") tool 100.
FIG. 2 is an illustration of an enlarged cross-sectional portion of LWD tool 100 of FIG. 1 in the region of collar 16, showing electronics assembly 14, turbine assembly 12, screen 30, alternator 38, turbine 39 and bypass assembly 31.
FIG. 3 is an illustration of an enlarged isometric portion of LWD tool 100 of FIG. 1 in the region of collar 16, showing electronics assembly 14, turbine assembly 12, screen 30, alternator 38, turbine 39 and bypass assembly 31.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will first be explained by reference to FIG. 1 which is an illustration of a typical drilling operation showing drilling rig 42 and logging while drilling ("LWD") tool 100.
Drilling rig 42 is generally a rotary drilling rig which as is well known in the drilling art, and comprises a mast 47 which rises above ground 5. Rotary drilling rig 42 is fitted with lifting gear from which is suspended a drill string 2 formed of a multiplicity of drill pipes 3 screwed one to another and having at its lower end a drill bit 49 for the purpose of drilling a wellbore 8.
Drilling mud is injected into wellbore 8 via the hollow pipes 3 of drill string 2. The drilling mud is generally drawn from a mud pit which may be fed with surplus mud from the wellbore 8.
The LWD tool 100 is located near the bottom of drill string 2 and may be attached to drilling string 2 by any suitable manner known to those of skill in the art, including with coupling 44 as shown.
LWD tool 100 includes LWD tool body 37 in which is housed power supply assembly 10. Although not shown, tool 100 further includes any desired instrumentation for measuring formation resistivity, neutron and density porosity, and acoustic travel time of the formations of interest. This data is processed in electronics assembly 14. Electrical power for LWD tool 100 is provided by power supply assembly 10 which includes a turbine/alternator assembly 12.
Turbine/alternator assembly 12 includes alternator assembly 18 having alternator 38 positioned within alternator housing 19. Turbine/alternator assembly 12 further includes turbine 39, having bearing housing 23, turbine shaft 20, turbine stator 26, shroud 29, seal assembly 22 and turbine rotor 28.
Referring additionally to FIG. 2, there is shown illustrated an enlarged cross-sectional portion of LWD tool 100 of FIG. 1, and to FIG. 3 there is shown illustrated an enlarged isometric portion of LWD tool 100 of FIG. 1.
As is shown in FIGS. 1-3, turbine/alternator assembly 12 is positioned within the inside diameter of drill collar 16, alternator assembly 18 is contained within the alternator housing 19, and turbine shaft bearings 51 and seal assembly 22 are contained within bearing housing 23.
The turbine/alternator assembly 12 is positioned within the collar 16 so that the flow of drilling fluid is in annulus 55 formed between the I.D.D. of collar 16 and the outside of the turbine/alternator assembly 12. As is illustrated in FIG. 2, the mud or drilling fluid flows in the downward direction as indicated by arrows M. At a given flowrate, the mean velocity of the flow M is directly proportional to the cross-sectional area of the flow annulus 55. At region A, the flow annulus 55 is defined by the O.D.D. of collar 16 and the O.D. of the alternator housing 19. As the flow M progresses downward to region B, the mud flow comes in contact with the slotted conical shaped screen/deflector 30. Simultaneously, the mud flow is aligned within a region of increased cross-sectional flow area, due to the fact that as the mud flow progresses downward along the turbine/alternator assembly 12, the instant that the flow comes in contact with the screen/deflector 30, it also encounters the reduced O.D.D. of the bearing housing 23 which increases the annular cross-sectional area exposed to the flow. This sudden increase in cross-sectional area creates a relative stagnation region in the flow field. At this point the flow is split; a portion of the flow proceeds through the conical screen/deflector 30 and a remaining portion flows through the flow bypass 32 at the O.D.D. of the bypass sleeve 34. The portion of the mud flow which passes through the screen/deflector 30 proceeds through the I.D. of the bypass sleeve 34 and through the turbine stator 26 and rotor 28 at which point rotational mechanical energy is extracted from the flow to drive the alternator assembly 38. A major benefit of the relative stagnation region experienced by the flow as it reaches the screen/deflector 30 is that it allows the portion of the flow which passes through the screen to evenly disperse across all of the open area of the screen. This, in turn, prevents excessive localized flow velocities through the screen which drastically reduces erosion.
The presence of the flow bypass 32 and bypass sleeve 34 allows the adaptation of the slotted, conical-shaped screen/deflector 30 to the turbine/alternator assembly 12. The screen/deflector 30 allows only filtered flow to pass through the turbine blades 26 and 28, thus drastically reducing the risk of plugging or jamming by debris. Any particles which are too large to pass through the slotted screen/deflector 30 are harmlessly deflected to the outside of the bypass sleeve 34 and through the flow bypass 32.
The utilization of the slotted screen/deflector 30, as in the present invention, prevents debris generated in the drilling operation from coming in contact with turbine blades 53, and thus allows the use of highly efficient, small clearance blade designs. Also, to further eliminate the formation of erosive tip vorticity on the turbine rotor, an attached cylindrical thin-walled shroud 29 is provided on the outside diameter of the rotor 28. This "shrouded" rotor design drastically improves the wear characteristics of the rotor 28 and adjacent hardware and thereby greatly increases the downhole operating life of the entire system.
In operation, as fluid flows through the turbine stator 26 and rotor 28, a pressure drop is encountered in the flow. That is, the pressure at the inlet of the turbine stator 26 is higher than the pressure at the exit of the turbine rotor 28. This drop in pressure across the turbine blades is related to the actual mechanical power extracted from the flow by the turbine. There is a minimum threshold for the required mechanical power generated by the turbine in order to adequately power the alternator and thus, the LWD system. This minimum threshold corresponds to a minimum acceptable flow rate through the actual turbine blades which, in the present turbine/alternator assembly 12, is 125 gpm. Because of the existence of the flow bypass 32, for any given LWD tool size (i.e. 63/4", 8", 91/2") the actual flow range through the turbine blades will be the same. For example, the minimum flow rate for a typical 63/4" LWD configuration may be about 250 gpm at which, due to the presence of the flow bypass 32, about 125 gpm passes through the conical screen/deflector 30 and through the turbine blades 53, and the remaining about 125 gpm passes through the flow bypass 32. Similarly, the maximum flow rate for a typical 63/4" LWD configuration may be about 750 gpm at which about 375 gpm passes through the turbine and the remaining about 375 gpm passes through the flow bypass 32. This means that in the 63/4" configuration, about 50% of the flow passes through the turbine 39 and about 50% passes through the bypass assembly 31. In order to prevent excessive erosion, the flow bypass is constructed so that the cross-sectional area perpendicular to the flow through the bypass is large enough to prevent high average velocities. For example, for the 63/4" configuration shown in FIG. 3, blades 53 of the bypass 32 are spiraled in order to create an appropriate balance in pressure drop between the bypassed flow and the flow which passes through the screen/deflector 30 and turbine blades 26 and 28.
For larger LWD tool sizes (i.e. 8" and 91/2"), the percentage of the total flow which passes through the turbine blades 53 is reduced in comparison to the 50% of the flow utilized in the 63/4" configuration. For example, in a typical 8" tool, the flow bypass may be configured so that about 33% of the total flow passes through the turbine blades 53 and about 67% is bypassed. As another example, in the typical 91/2" tool, the flow bypass is configured so that only about 25% of the total flow passes through the turbine blades while the remaining about 75% is bypassed. In both examples, of the typical 8" and 91/2" configurations, the cross-sectional flow areas of the bypass arrangements are adequate to prevent excessive erosion at the respective maximum flow limits. In any of the three given example tool sizes, the same range of flow is directed through the screen/deflector 30 and turbine blades 53 for power generation. Thus, the actual percentage of flow bypass will generally be varied between different tool sizes.
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 herein 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 this invention pertains.
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A logging-while-drilling tool for use in a wellbore in which a well fluid is circulated into the wellbore through the hollow drill string. In addition to measurement electronics, the tool includes an alternator for providing power to the electronics, and a turbine for driving the alternator. The turbine blades are driven by the well fluid introduced into the hollow drill string. The tool also includes a deflector to deflect a portion of the well fluid away from the turbine blades.
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BACKGROUND OF THE INVENTION
This invention relates to fibre combing, an operation in which the fibrous material is fed in the form of a thin-layer blanket, known as a lap, rolled into a package of roll shape and formed by combining and drafting a plurality of fibre slivers originating from carding, and is processed with intermittent motion and rigorous synchronism by a series of mutually cooperating members, such as feed rollers, gripper surfaces, combs formed from circular sectors, etc. For more information on combing devices and their operation, reference should be made to EP 573,121 in the name of the present applicant.
In machines of the most recent design, this process is conducted at a rate of 250-400 beats per minute, and is performed on the edge of the lap which is presented to the comb, ie the fringe. The combing operation is performed on fibres intended for high-value articles, its purpose being to give them those characteristics which carding is not able to give. Its basic purpose is to improve fibre parallelism by avoiding so-called fluctuating fibres, to eliminate a certain quantity of short fibers, and finally to remove impurities and trash. Basically, combing consists of selectively transferring combed long fibre tufts drawn from the feed lap to the product lap, while eliminating trash, which is removed, and the short fibres, which represent a by-product usable for articles of lesser value. Combing machines generally consist of six-eight combing stations or "heads", and more generally of the order of magnitude of ten heads per machine. The product laps from the machine combing stations are then combined to form the product web of combed fibres, which are cleaner, more regular and stronger. Combing machines are generally provided with drives and controls common to the various stations, which are jointly started and halted. This latter occurs in particular when the feed lap package is depleted and has to be replaced with a new package. As already stated, these packages are in the form of a roll having a length of the order of 300 mm and a diameter of the order of 500 mm, in which the lap is wound on a cylindrical tube forming its core. When the feed to one of the stations terminates, all the feed laps in all the stations are generally replaced, even if their set length has not yet been consumed. This operation consists of removing the lap tubes together with any remaining wound lap, replacing them with new lap packages, and preparing the initial edge of the new lap to enable it to be effectively and reliably joined to the tail edge of the preceding lap, which is re-fed to the members of the combing station.
SUMMARY OF THE INVENTION
In particular, the present invention relates to said feed lap replacement operation in a combing machine, and provides a device and method for carrying out all the steps of the replacement operation described in the preceding paragraph without the aid of operators.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics and advantages of the present invention will be more apparent from the description of a typical embodiment thereof illustrated in FIGS. 1 to 7 by way of non-limiting example, which show a side view of one of the constituent combing stations of the machine, and illustrate the various steps in the lap replacement operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows on its right side a combing station in normal operation. The unwinding lap 1 is located in its working position by simply resting on the unwinding rollers 2 which rotate clockwise to cause the lap roll 1 resting on them to rotate anticlockwise. The edge 3 of the unwound lap passes firstly onto the flat ledge 4 for edge resting, positioning and joining - described in detail in relation to the successive steps of the method - and then, by the action of the motorized drive roller 5, passes to the adjustable lap guide blade 6 located to the front right of the lap, to be dragged by the feed roller and enter the actual combing stage.
This latter operation does not strictly concern the present invention, its members being shown only schematically in the detailed view of FIG. 1A, in which:
7 indicates the gripper unit which moves and grips alternately,
8 indicates the lap feed roller,
9 indicates the straight comb which cooperates with the rotary comb,
10 indicates the rotary comb with its circular sector provided with points,
11 and 12 indicate the grabbing rollers which cause the combed web to advance and recede to gradually take up the tufts processed by the combs.
During the processing of the lap 1, a reserve lap 1' is brought to the combing station to replace the lap 1 in its winding position when this latter lap is depleted or when its replacement is ordered. This reserve lap 1' is located on a chute 20 slightly inclined towards the unwinding position and provided with lateral guides, not shown in the figure, the lap being retained resting on a stop arm 21 which is able to assume two alternate positions, namely a raised position to retain the lap 1', as indicated in FIG. 1, or a lowered position which releases the lap 1', as indicated in FIG. 3. The replacement laps can be advantageously transported by automated means, for example by the transportation system described in EP-A-312,503 in the name of the present applicant, which is able to operate both with complete laps and with empty tubes.
The initial edge of the reserve lap 1' must be prepared before the replacement. It is prepared by inserting it both into the gripper 22 and into the pair of stretching rollers 23, which are both closed after this insertion, after which said stretching rollers are briefly operated. The edge is prepared by stretch-breaking within the length between said two members. Downstream of the pair of rollers 23 there is a suction duct 24 which draws off the portion removed from the lap. The edge 25 of the new lap 1' is thus prepared.
The unwinding of the lap 1 resting on its rollers 2 proceeds to the end. It can be seen that this method of operation enables the lap to be unwound at constant linear speed as the diameter of the lap roll varies, this gradually increasing its rotational speed in proportion to the reduction in its diameter. The progressive depletion of the lap and the length unwound are measured by a totalizing revolution counter applied to the rollers 2 and connected to the machine control unit.
When a first set length is reached in one of the machine combing heads, the combing machine control unit causes it to run at reduced speed. When a second set length is reached the machine is halted, as are the members downstream of the flat resting ledge 4. preparation for lap change is shown in FIGS. 2 and 3. The gripper 22 and the rollers 23 are again opened to release the initial edge 25 of the new lap with its prepared fringe. The backing roller 26 is brought up to the drive roller 5 to grip the portion 3 of the depleting lap 1 and clamp it. This portion is now wound with the final winding revolutions of the lap 1 about its tube and is rested on the unwinding rollers 2. These rollers are then disconnected from their normal clockwise drive for unwinding the lap and are instead connected to a different anticlockwise drive. The rollers 2 are then operated to rewind the edge portion 3 back on its tube. Said edge portion is retained by the contacting pair of rollers 5 and 26 and is torn off in the vicinity of the right roller 2 where it has its point of least resistance. Slits 27 are provided in the flat resting ledge 4 and are connected to a suction system by a duct 28. According to an important characteristic of the present invention, said suction system is able to apply suction at different levels of intensity. During lap change a moderate suction is maintained, sufficient to reliably retain the fringe of the terminal edge of the lap 1 on said ledge 4, for example a suction of 10-20 mm of water column.
With reference to the situation shown in FIG. 3, the elevator fork 29 is now raised to move the residue of the lap 1 with its tube to the unloading position. The elevator 29 moves vertically along a guide 30 which is slightly curved at its upper end to move the residual lap to an automatic transport station 31, for example of the type already mentioned. The tube is then freed from the residual lap and reused in the lap preparation station. The fork 29 travels along its guide in the reverse direction to return to its lower rest position.
The stop arm 21 is moved into its lowered position to release the lap 1', which rolls towards the right to assume the configuration shown in FIG. 4. The rolling motion is slightly braked by the lateral guides, not shown, of the inclined surface 20, which enable the new lap 1' to reach and halt in a position resting on the unwinding rollers 2. In any eventuality, the downstream bar 32 acts as a safety stop.
As a result of this rolling, the initial edge 25 of the new lap 1' deposits on and straddles the bar 32, which acts as a receiver for this edge and extends along the entire face of the machine. As in the case of the ledge 4, the bar 32 comprises one or more longitudinal slits connected to a suction system (for simplicity not shown in the figure) by which, during the changing of the lap, sufficient suction is applied to retain the initial edge fringe of the lap 1' and prevent it falling uncontrolledly off the bar. As shown in FIG. 5, the rollers 2 are driven in an anticlockwise direction to rewind the edge 25 back on its tube, so making the edge 25 withdraw from the bar 32 and allowing it to deposit on the ledge 4, on which it is retained by the moderate suction action already described.
During this, and in accordance with an important characteristic of the method of the present invention, the rotation of the rollers 2 is carefully controlled such that the length L by which the end edge of the preceding lap 1 and the initial edge of the new lap 1' are superposed is between 30 and 70 mm and preferably between 40 and 60 mm along their entire width. After said superposing of the two edges, the suction through the duct 28 is raised to its highest value for a time of the order of a few seconds, to achieve pneumatic joining. For example, the suction is raised to 30-40 mm water column for a time of 5-15 seconds. In this respect, this strong air flow drawn through the slits 27 tangles the fibres of the two edge fringes together, to create a continuity which is weak, but is sufficient for resuming the process.
The machine is now ready for the restart, shown in FIG. 6. The unwinding rollers 2 are reconnected to their normal clockwise drive for unwinding the lap 1'. The combing station is restarted at low speed, maintaining the backing roller 26 still pressed against the drive roller 5. The passage of the joined edges through said rollers further increases the cohesion between their fringes. The adjustable guide blade 6 facilitates the passage and conveying of the two layers, compacted but still very delicate, as far as the lap feed roller 8 and enables the new portion 3 to pass through the combing members without problems. The blade 6 is also very useful in guiding the lap feed during the normal combing, in that its protection and guiding effect prevents wavy movements deriving from the pulsation-type retraction of the combing members.
The configuration of FIG. 7 corresponds to the normal combing rate, which is restored when the joined portion has passed beyond the combing members and has been combined with the product of the other machine combing stations, the various joined portions hence being offset and practically no longer distinguishable. When the machine is in this state, the backing roller 26 is in its withdrawn rest position, the unwinding rollers and the other members operate at their normal working speed, and a new reserve lap 1' is put in position. It must then be prepared by the procedure illustrated in FIG. 1, the members for preparing the edge 25 being already in their open waiting position.
Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined the appended claims.
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A method for automatically replacing laps in a combing machine, comprising clamping the depleting lap portion, preparing it and retaining its terminal edge fringe, loading the new lap, preparing its initial edge fringe, superposing the edge fringes and joining them pneumatically, then restarting combing.
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TECHNICAL FIELD
[0001] The present invention generally relates to medical imaging devices, more particularly, to devices for the wireless controlled movement of medical imaging equipment.
BACKGROUND OF THE INVENTION
[0002] Most interventional imaging systems use an X-ray source connected to an image intensifier (I-I) which can be utilized before, during and after a procedure. As in other medical procedures, the operator may be an assistant to the medical practitioner guided under the practitioner's directions. Typically, this requires either the operator or an assistant to physically move or adjust the imaging system using a joystick (or other manual mechanism requiring hands on) on an examination table. The medical practitioner may prefer the benefit of both controlling such an imaging system while performing the procedure. In order to operate such imaging systems, the unit is moved in various directions using hand held controls on the operating table. Movement of this device is necessary to obtain desired views of the object/patient being studied.
[0003] Potential problems with this approach include the operator having to take his hands off of the procedure to adjust the imaging, which can lead to complications of a medical error or increased time to perform the procedure. In another example, an assistant may have other responsibilities during the procedure such that repositioning the camera may introduce positional error and, similarly, prevents the assistant from concentrating on another related task. There are instances when considerable movement occurs during a critical part of the procedure, thus adding to complexity and risk of a medical error or injury to the subject.
[0004] Current operation of such imaging systems have progressed over the years to allow not only improved optical resolution and subminiature size but also improved responsiveness through the use of various user interface options such as handheld controls, joystick, mouse, or touch screen. These advances, though furthering the capacity and utility of this technology, still leave room for improvement by still sharing the common requirement to utilize the hands of the person controlling the system. This presents complications when the medical practitioner needs use of the hands for other related tasks. Therefore, as medical procedures get increasing complex there is a need for a device that can help solve or reduce the need for medical personnel to correct imaging apparatus or take away the medical personnel from the surgical treatment at hand.
[0005] In light of the foregoing considerations, and relative to the present state of the art, the need for hands-free control or guidance of I-I imaging systems remains to be sufficiently addressed. Furthermore, it remains desirable and advantageous to more efficiently maneuver such imaging systems without taking attention from other related tasks so as to create an error or risk to the subject. Finally, having a hands-free solution that can track a medical practitioner's movements, without the need for third party interaction satisfies the operators visualization requirement without having to interrupt the procedure.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to provide a wireless control device that will enable the user to guide the position of an I-I imaging system without the use of the user's hands. It is a further object of the present invention to a provide a highly responsive wireless control that may enable the user to multitask by performing an independent task with the hands while simultaneously guiding the imaging system. In one embodiment of the present invention, the wireless control mechanism that controls the guided imaging system may be mounted on the body of the user. In one embodiment of the present invention, the wireless control mechanism that controls the guided imaging system may be mounted on the head or upon a headpiece of the user. In a further embodiment of the present invention, the wireless control mechanism that controls the guided imaging system may include a voice activated control system for enabling the user to use voice commands to activate and operate the guided imaging system. The voice activated control system may comprise an audio microphone configured to receive audio or voice input commands or signals from the user, an audio receiving unit for receiving the audio or voice input commands or signals, and an audio or voice signal processor coupled to the audio receiving unit for processing the audio or voice input commands or signals. In one embodiment of the present invention, the guided imaging system may be used in a sterile environment. In a further embodiment of the present invention, the guided imaging system may be used in a healthcare facility.
[0007] In yet another embodiment of the present invention, the guided imaging system may respond similarly to that of the Nintendo Wii® controller. In one embodiment of the present invention the wireless controller may be capable of responding to direction in one or more of the following linear directions: horizontal (X), vertical (Y) and depth (Z) directions and communicate these directions to the I-I. In one embodiment of the present invention the I-I may be capable of responding to direction in one or more of the following rotational directions: pitch (rotation about the vertical axis), roll (rotation about the horizontal axis), and yawl (rotation about the depth axis). In a further embodiment of the present invention, the speed of movement of the user may be translated into the speed at which the guided imaging system, (I-I) movement, responds. The speed of movement may further accompany one of the linear directions or one or more of the rotational directions.
[0008] In another embodiment of the present invention the imaging monitors may be capable of responding to direction independently or in concert with the movement of the I-I, as shown in FIG. 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of preferred embodiments of the invention with reference to the drawings. In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principals, elements and inter-relationships of the invention.
[0010] FIG. 1 is a drawing of a C-arm imaging system having an image intensifier and controllers to position both the imager and table holding the object under observation.
[0011] FIG. 2 is a drawing of an image system having an image sensor in multiple positions relative to the x-ray source that can include single or multiple image arrays.
[0012] FIG. 3 is a drawing of an image system mountable from a wall or ceiling that incorporates monitors and having a swivel adjustable sensor.
[0013] FIG. 4 is a drawing of an image system having an image sensor mountable on an examination table.
[0014] FIG. 5 is a drawing of a headband mountable device having a wireless transmitter and sensors built therein.
[0015] FIG. 6 is a drawing of a wireless controller for an image system that is attachable to eyewear of the user.
[0016] FIG. 7 is a drawing of a wireless controller for an image system that is built into eyewear.
[0017] FIG. 8 is a drawing of a wireless controller for an image system that is built into gloves.
[0018] FIG. 9 is a drawing of a voice activating system.
DETAILED DESCRIPTION
[0019] FIG. 1 illustrates two configurations of an interventional guided imaging system 100 , according to one embodiment of the present invention, having an x-ray source 101 opposite an image intensifier (I-I) 120 . Imaging systems of this type may be moved in various directions using handheld controls on or near an examination table. Movement of the imager is necessary to obtain desired views of the object/patient under examination without the need to move object/patient. Typically, the user or an assistant will physically reposition the camera and monitors using a joystick control on the examination table. This occurs during a medical procedure, which can distract the operator from the procedure and present complications for the patient. In FIG. 2 , the sensor of the image intensifier is located above a flat plane. This may include either a single or a multiple array (bi-plane) configuration.
[0020] Referring further to FIG. 1 , which illustrates one embodiment of construction of a single plane type x-ray interventional guided imaging system 100 in accordance with the present invention. The x-ray interventional guided imaging system 100 includes an x-ray source 101 for irradiating x-rays onto an object P and an x-ray detecting unit 102 for collecting x-ray projection data by two dimensionally detecting x-rays penetrated through an object P. The x-ray source 101 and the penetrated x-ray detecting unit 102 are respectively supported at opposed edge portions of the C-shaped support arm 132 a . The x-ray interventional guided imaging system 100 further includes a drive unit 103 for implementing rotating movements of C-shaped support arm 132 a and position movements of top plate 131 a in order to support an object P and a high voltage generator 141 . The high voltage generator 141 supplies a high voltage sufficient for production of x-rays and irradiation of x-ray to the x-ray source 101 .
[0021] The drive unit 103 includes a top plate moving mechanism 131 , a C-shaped support arm 132 a and a C-arm/top plate mechanism controller 133 for controlling movements of both mechanisms 131 and 132 . The top plate moving mechanism 131 moves the top plate 131 a for supporting an object P along a body axis direction, a width direction of the top plate and up and down. The C-arm rotation-moving mechanism 132 performs rotation movements of C-shaped support arm 132 a around an object P. C-shaped support arm 132 a supports the x-ray source 101 and the penetrated x-ray detecting unit 102 . The C-arm/top plate mechanism controller 133 controls each operations of the respective movements of the top plate moving mechanism 131 and movements or rotations of the C-arm rotation-moving mechanism 132 based on control signals supplied from the system controller 110 so as to position an imaging object, such as blood vessel, and x-ray radiation unit at a plurality of different angle positions in order to perform x-ray radiography at appropriate angle positions while avoiding obstacles, such as bones, as explained later.
[0022] The top plate moving mechanism 131 includes a sensor (not shown), such as an encoder, for detecting a moved distance of the top plate 131 a . C-arm/top plate mechanism controller 133 controls the top plate moving mechanism 131 based on the detected signals supplied from the moved distance sensor. The top plate moving mechanism 131 moves the top plate 131 a so as to set it at desired positions based on the control signals from the C-arm/top plate mechanism controller 133 . Similarly, C-arm rotating-moving mechanism 132 includes a rotating angle sensor (not shown), such as an encoder for detecting rotated angles of the C-shaped support arm 132 a . C-arm rotation-moving mechanism 132 rotates the C-shaped support arm 132 a under control from the C-arm/top plate mechanism controller 133 based on the angle position of the detected living body. By the rotations of the C-shaped support arm 132 a , a pair of the x-ray interventional guided imaging system 100 and the x-ray detecting units 102 are positioned at desired radiography angle positions and distances based on the controlling signals from the C-arm/top plate mechanism controller 133 . When the C-shaped support arm 132 a is positioned at a desired position, the C-arm rotation-moving mechanism 132 supplies an angle positioned signal of the positioned radiography angle position to the system controller 110 .
[0023] The x-ray interventional guided imaging system 100 includes an x-ray tube 111 for generating x-rays and an x-ray collimator 112 . The x-ray collimator 112 restricts an x-ray irradiation area over an object P from the x-ray tube 111 . A high voltage generating unit 104 supplies a high voltage to the x-ray tube 111 in x-ray interventional guided imaging system 100 . The high voltage generating unit 104 includes a high voltage generator 141 and an x-ray controller 142 that controls the high voltage generator 141 based on control signals supplied from a system controller 110 .
[0024] X-ray detecting unit 102 includes an image intensifier (I.I.) 120 that detects x-rays penetrated through an object P and converts the penetrated x-rays to light signals, a television (TV) camera 122 for converting the light signals to electric signals and an analog-to-digital (A/D) converter (not shown) for converting electric signals from the TV camera 122 to digital signals. X-ray projection data converted to digital signals are thereby supplied to a pixel data processing unit 106 . I.I. 120 includes a moving mechanism so as to move its positions forward and backward so as to face the x-ray interventional guided imaging system 100 . Thus, a distance between the x-ray generating source and the x-ray detector (Source to Detector Distance: SDD) can be adjusted. Further adjustment can be made to the x-ray incidence view size (Field Of View: FOV) by controlling electric voltages of an x-ray receiving surface electrode of I.I. 120 . In this embodiment, an I.I. is illustrated as a detector. It is, of course, possible to apply a plate surface type detector (Flat Panel Detector: FPD) in order to convert the detected x-rays to electric charges.
[0025] Pixel data processing unit 106 generates pixel data from x-ray projection data that are generated in the x-ray detecting unit 102 . The generated pixel data are stored. Thus, the pixel data processing unit 106 includes a pixel data generating unit 161 for generating pixel data and a pixel data memory unit 162 for storing the generated pixel data. Pixel data generating unit 161 generates pixel data in accordance with x-ray radiography data being supplied from the detector 102 and managing vital data of an object P being supplied from a vital data measuring unit 105 through a system controller 110 . The vital data measuring unit 105 includes a sensor 151 for detecting and measuring various physiological statistics of object P, and a signal processing unit 152 for converting and processing the measured various physiological statistics in vital data for pixel data generating unit 161 . The generated pixel data are stored in a pixel data memory unit 162 .
[0026] Pixel data that are collected, which include at least at two different angle positions and stored in the pixel data memory unit 162 , are supplied to a three dimensional image generating unit 166 . The three dimensional image generating unit 166 generates three dimensional image data from pixel data collected at least at two different positions. To generate three dimensional image data, vital data are supplied from a vital data measuring unit 105 through the system controller 110 in order to select pixel data of the same phase of at least two different positions. The generated three dimensional data is displayed on a display unit 108 .
[0027] The interventional guided imaging system 100 further includes a pixel data searching unit 107 for searching a plurality of pixel data stored in the pixel data memory unit 162 . Pixel data searching unit 107 searches for a plurality of pixel data of the same phase among a plurality of pixel data stored in the pixel data memory unit 162 , and a reduced pixel data generating unit 172 generates reduced pixel data from the searched pixel data of the same phase. A plurality of sets of the generated reduced pixel data of the same phase are displayed on a screen of a display unit 108 . Thus, either a plurality of sets of pixel data of the same phase that are generated in the three dimensional image data generating unit 166 or a plurality of sets of reduced pixel data reduced of the same phase that are generated in the pixel data generating unit 172 are displayed on the display unit 108 .
[0028] The interventional guided imaging system 100 further includes an operation unit 109 for inputting various setting conditions or commands The operation unit 109 designates various inputs of radiography conditions, such as, input operations of an object ID, such as a name of an object P and respective times of radiography, image magnifying ratio, designation of setting positions of the C-arm, designation of setting position of radiography angles, designation of setting position of the top plate, and a selection of static images or successive images that are collected at a time series during a certain time period (hereinafter, simply referred to as “a motion image”), and various conditions for displaying. In order to select a motion image, the operation unit 109 further inputs additional radiography conditions of a frame rate indicating a frame number in a unit time and an irradiation time. The system controller 110 totally controls the overall operation of the apparatus in accordance with the inputted conditions from the operation unit 109 .
[0029] FIG. 2 illustrates an image system 200 having an image sensor in mountable positions relative to the x-ray source, according to one embodiment of the present invention. Such configurations may include single or multiple image arrays. C-arm imaging system 210 includes a C-shaped support arm which contains both the I-I and sensor 215 at the top to communicate with an external position controller (not shown). G-Image system 220 includes a support arm similar in function to the C-shaped support arm of C-Image system 210 , however, having a planar vertical surface extending between the I-I with sensor 215 and the x-ray source 216 . Such configurations may include either flat plane or adjustable plane mechanisms.
[0030] FIG. 3 illustrates a ceiling mountable guided imaging system 300 , having a swivel mount sensor 315 and adjacent multiple monitors 325 , according to one embodiment of the present invention. In this configuration, the sensing of rotational directions on the user-worn wireless transmitter (not shown) sends communication signals to the swivel mount sensor 315 , which may implement rotational or linear movement of the multiple monitors 325 .
[0031] FIG. 4 illustrates a table-mounted guided imaging system 400 , according to one embodiment of the present invention, in which the I-I and sensor 415 mounts on the side of the examination/observation table 430 . The I-I and sensor 415 points horizontally across the plane of the table 430 toward an x-ray source (not shown).
[0032] FIG. 5 is a drawing of a head-mountable wireless controller 500 . In this configuration, the control device includes an elastic membrane 505 on a first side opposite a second side which may contain one or more sensors 515 . The sensors 515 also send communications to the system controller 110 for controlling movements of both the top plate moving mechanism 131 , and the C-arm rotation-moving mechanism 132 , by the C-arm/top plate mechanism controller 133 , including, for example, implementing rotating movements of C-shaped support arm 132 a and position movements of top plate 131 a , as described above. The sensors 515 also send communications to the system controller 110 for controlling the multiple monitors 325 as described above. Motion of the head may direct motion of the imaging system 500 and monitors 325 either independently or on concert with one another.
[0033] It is within the scope of this invention that a control mechanism such as a switch or button on the wireless embodiments that will allow the user to differentiate commands from the position or movement of the user to one or more controlled systems (e.g., remotely controlling the C-arm imaging system 210 or the multiple monitors 325 or individual I-I's in a multi-plane system). The sensors 515 may comprise the ability to sense position or movement in one or more of the following linear directions: horizontal (X), vertical (Y) and depth (Z) directions. In one embodiment of the present invention the wireless controller 500 may comprise sensors 515 capable of sensing movement in one or more of the following rotational directions: pitch (rotation about the vertical axis), roll (rotation about the horizontal axis), and yawl (rotation about the depth axis). One example of this type of wireless control response is that of the Nintendo Wii® controller used with the Nintendo Wii® game system. This design concept utilizes accelerometers that allow the wireless controller to detect the motion of the controller. The motion is communicated to the I-I which is translated into motion of the imaging system 210 and may be used to position the I-I or monitors 325 or both. There are also tiny silicon springs inside the controller that detect motions, positions, and tilt. The wireless communication between the handheld unit and console is infrared. Although infrared is common in industry as a wireless communication protocol, there are several others which are contemplated to be used in the present invention. Some examples include Bluetooth, wireless fidelity radio frequency (also known as WiFi) which follows IEEE standard 802.11a/b/g/n and cellular frequencies. Some RF wireless modules available on the market include Linx Technologies LT, LR and LC Series transceivers. These provide either uni-directional or bi-directional communication with serial data and command signals.
[0034] In a further embodiment of the present invention, the sensors 515 may be capable of sensing speed of movement of the user. This sensed speed may then be translated into the speed at which the guided imaging system 100 responds to movement by the user.
[0035] FIG. 6 is a drawing of a head-mountable wireless controller 600 , according to one embodiment of the present invention. In this configuration, the control device includes sensors 615 which may be attachable to the eyewear of the user. Eyewear may include eyeglasses, safety glasses/goggles or other eyewear commonly utilized while operating an imaging system.
[0036] FIG. 7 is a drawing of a head-mountable wireless controller 700 , according to one embodiment of the present invention. In this configuration, the control device includes eyewear 705 comprising sensors 715 mounted or molded into the frame of the eyewear 705 . Similarly, as contemplated in the example of FIG. 6 , this embodiment can be utilized in a variety of types of eyewear.
[0037] FIG. 8 illustrates a glove-mounted wireless controller 800 , according to one embodiment of the present invention. In this embodiment, either the dorsal side 804 or the palm side 806 of the glove-mounted controller 800 comprise sensors 815 . It is contemplated that even both sides of the glove-mounted wireless controller 800 may comprise sensors 815 capable of linear or rotational direction as well as speed sense.
[0038] FIG. 9 is a drawing of a voice activated system 900 , according to one embodiment of the present invention. In this configuration, a microphone 901 is coupled to an audio mixer/preamplifier 902 . Embodiments of the microphone 901 may include a wired microphone, a wireless microphone, or a shotgun microphone which allows the user to be move about without being tethered to by wires or cables, or without wearing a wireless microphone system. The voice activated system 900 further includes an audio amplifier 903 coupled to the audio mixer/preamplifier 902 . Audio mixer/preamplifier 902 and audio amplifier 903 are coupled to an audio processing unit 904 . Audio processing unit 904 may be communicatively coupled to the I-I or monitors 325 or both. The means of communication between the audio processing unit 904 and the I-I or monitors 325 or both may include Bluetooth, wireless fidelity radio frequency (also known as WiFi) which follows IEEE standard 802.11a/b/g/n and cellular frequencies. Examples of the audio processing unit 904 may include a computer comprising a memory and a processor. Audio processing unit 904 may operate under the control of voice recognition software. The voice control system recognizes a series of key words which corresponds to a command or series of commands that may otherwise be initiated through manual commands or controls. After recognition, the voice control system may repeat the recognized command or series of commands, and execute the command. The command or series of commands are communicated to the I-I which is translated into motion of the imaging system 210 and may be used to position the I-I or monitors 325 or both. Operations controlled by the voice activated control system may include directing the guided imaging system, (I-I), in one or more of the following linear directions: horizontal (X), vertical (Y) and depth (Z) directions, directing the I-I in one or more of the following rotational directions: pitch (rotation about the vertical axis), roll (rotation about the horizontal axis), and yawl (rotation about the depth axis), and adjusting the speed at which the I-I moves at one of the linear directions or one or more of the rotational directions. Operations controlled by the voice activated control system may also include directing the imaging monitors independently or in concert with the movement of the I-I. Operations controlled by voice activated control system may also include designation of various inputs of radiography conditions, such as, input operations of an object ID, such as a name of an object and respective times of radiography, image magnifying ratio, designation of setting positions of the C-arm, designation of setting position of radiography angles, designation of setting position of the top plate, and a selection of static images or successive images that are collected at a time series during a certain time period, and various conditions for displaying.
[0039] There are other variations or variants of the described methods of the subject invention which will become obvious to those skilled in the art. It will be understood that this disclosure, in many respects is only illustrative. Although various aspects of the present invention have been described with respect to various embodiments thereof, it will be understood that the invention is entitled to protection within the full scope of the appended claims.
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Apparatus for wirelessly controlling a guided imaging system based upon the relative motion of the user. The system includes a power supply, a memory, an x-ray source, an image intensifier and a wireless transceiver coupled to the image intensifier. A separate wireless input device comprising a wireless transmitter for communicating with the wireless transceiver of the imaging system may comprise one or more sensors capable of detecting force and directional movement. This detection of movement may then be transmitted to the imaging system and translated into position signals that may direct movement and position of the image intensifier (I-I) as part of the imaging system.
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RELATED APPLICATION
[0001] This application claims priority as a continuation application under 35 U.S.C. §120 to PCT/EP2015/054970, which was filed as an International Application on Mar. 10, 2015 designating the U.S., and which claims priority to European Application 14158951.5 filed in Europe on Mar. 11, 2014. The entire contents of these applications are hereby incorporated by reference in their entireties.
FIELD
[0002] The present disclosure relates to a reactive polyurethane composition which can be applied in liquid form at room temperature and which can, for example, be used as a coating in order to seal construction work in respect of ingress of water.
BACKGROUND INFORMATION
[0003] For quite some time reactive polyurethane compositions have been known which can be applied in liquid form and which are used as coatings that provide bridging over cracks in order to seal construction work in respect of ingress of water; they are also termed liquid membranes. In comparison with prefabricated polymer webs, they provide easier application, in particular when surfaces are uneven or have complex geometry, they improve protection from below-surface migration by virtue of adhesion to the substrate across the entire area, and they also provide seamless laying. In comparison with non-reactive systems applied in liquid form, for example polymer solutions, aqueous polymer dispersions, or bitumen-based products, they feature high strength and good resilience, even at low temperatures, have low susceptibility to soiling, and provide durable sealing even under standing water.
[0004] The properties of a hardened liquid membrane in providing bridging over cracks over a wide temperature range are important for reliable prevention of water ingress into construction work. In order to achieve this, the hardened material should have high extensibility, high strength, and good tear strength. A rather low value for modulus of elasticity is advantageous here, in order that movements caused by way of example by temperature variation or vibrations in the construction work do not give rise to stresses in the membrane that are excessive and that can cause separation of the membrane from the substrate or cohesive fracture within the substrate. The latter can be especially critical in the case of substrates having low resistance to pressure, an example being insulation foam.
[0005] The expression polyurethane liquid membranes covers not only one-component systems but also two-component systems. Curing of one-component polyurethane liquid membranes is brought about by moisture, and takes place from the outside toward the inside, and these membranes therefore require a relatively long time for complete curing throughout the material, in particular when thick layers are used, the environment is dry, or there is restricted availability of moisture; this can impact on subsequent operations. Commercially available products moreover include considerable content of volatile organic solvents, firstly in order to increase shelf life, and secondly in order to reduce viscosity and thus improve ease of use. For this reason, they emit VOC, discernible by their strong odor, and they exhibit a degree of shrinkage.
[0006] In contrast to this, two-component polyurethane liquid membranes, even those with high solids content, have comparatively low viscosity, and are therefore easy to apply; they also cure rapidly throughout the material, even when the materials are relatively thick. However, during hardening they are very sensitive to moisture and temperature. If humidity is high, in particular when this is combined with high temperatures, or the substrate is damp, or there is direct contact with water, evolution of CO 2 can form bubbles; this leads to foaming of the coating, and impairs its sealing function and robustness; in warm conditions they have a short open time, and at low temperatures they cure very slowly or remain soft and tacky. Furthermore, many known two-component products include solvents and/or volatile isocyanates, and can impact on protection of the environment and prevention of health hazards.
SUMMARY
[0007] A composition is disclosed which is composed of: a first component comprising: at least one polymer polyol which is a dispersion of a polymer that is solid at room temperature in a polyether polyol that is liquid at room temperature, at least one diol chain extender and optionally other polyols; and a second component comprising: diphenylmethane diisocyanate; where at least one of the two components additionally comprises at least one aldimine of the formula (I),
[0000]
[0000] where A is an (m+n)-valent hydrocarbon moiety which optionally comprises ether units and which has from 2 to 20 C atoms, X is O or N—R 5 , R 1 and R 2 are mutually independently respectively a monovalent hydrocarbon moiety having from 1 to 12 C atoms, or together are a divalent hydrocarbon moiety which has from 4 to 12 C atoms and which is part of an optionally substituted carbocyclic ring having from 5 to 8; R 3 is a hydrogen atom or is an alkyl or arylalkyl or alkoxycarbonyl moiety having from 1 to 12 C atoms; R 4 is a monovalent hydrocarbon moiety which has from 6 to 20 C atoms and which optionally comprises ether units or aldehyde units; R 5 is a monovalent hydrocarbon moiety which has from 1 to 30 C atoms and which optionally comprises at least one carboxylic ester group, nitrile group, nitro group, phosphonic ester group, sulfonic group or sulfonic ester group, or a group of the formula
[0000]
[0000] and
m is 0 or 1, and n is 1 or 2 or 3, with the proviso that m+n is 2 or 3.
DETAILED DESCRIPTION
[0008] Exemplary solvent-free polyurethane compositions are disclosed which have little odor and which contain no volatile isocyanates, which are suitable as two-component liquid membrane for the sealing of construction work, and which exhibit long shelf life of the components, excellent ease of use in manual application, rapid and problem-free hardening over a wide range of temperature and of moisture level, and good weathering resistance.
[0009] Surprisingly it has been found that a composition as disclosed herein can achieve the foregoing effects. It is free from solvents and from volatile isocyanates such as TDI or IPDI, and from substances having strong odor, and it has a long open time with very low viscosity, and therefore has excellent suitability for manual application. The combination of polymer polyol, diol chain extender, and aldimine, the latter having little to no odor, with non-volatile MDI in the second component provides access to very low viscosity with long open time, excellent curing throughout the material with almost no formation of bubbles, excellent mechanical properties, with high strength and extensibility, with low modulus of elasticity, and good weathering resistance of the hardened material.
[0010] It is particularly surprising here that, despite the high reactivity of MDI, and the diol chain extender, the composition has a long open time, and hardens substantially without the presence of bubbles, and moreover develops very good mechanical properties, although the plasticizing aldehyde remains within the composition.
[0011] It is moreover particularly surprising that, by virtue of the polymer polyol, the tensile strength of the composition is significantly increased, while modulus of elasticity either rises insignificantly or remains approximately the same, or actually decreases; this is particularly advantageous for applications on substrates having low resistance to pressure, for example insulation foams.
[0012] A composition as disclosed herein can be composed of a first component comprising:
at least one polymer polyol which is a dispersion of a polymer that is solid at room temperature in a polyether polyol that is liquid at room temperature, at least one diol chain extender and optionally other polyols;
and a second component comprising diphenylmethane diisocyanate;
where at least one of the two components additionally comprises at least one aldimine of the formula (I),
[0000]
[0000] where
A is an (m+n)-valent hydrocarbon moiety which optionally comprises ether units and which has from 2 to 20 C atoms,
X is O or N—R 5 ,
[0016] R 1 and R 2 are mutually independently respectively a monovalent hydrocarbon moiety having from 1 to 12 C atoms, or together are a divalent hydrocarbon moiety which has from 4 to 12 C atoms and which is part of an optionally substituted carbocyclic ring having from 5 to 8, preferably 6, C atoms;
R 3 is a hydrogen atom or is an alkyl or arylalkyl or alkoxycarbonyl moiety having from 1 to 12 C atoms;
R 4 is a monovalent hydrocarbon moiety which has from 6 to 20 C atoms and which optionally comprises ether units or aldehyde units;
R 5 is a monovalent hydrocarbon moiety which has from 1 to 30 C atoms and which optionally comprises at least one carboxylic ester group, nitrile group, nitro group, phosphonic ester group, sulfonic group or sulfonic ester group, or a group of the formula
[0000]
[0000] and
m is 0 or 1, and n is 1 or 2 or 3, with the proviso that m+n is 2 or 3.
[0017] The expression “diol chain extender” means an organic diol which is not a polymer.
[0018] The expression “diphenylmethane diisocyanate”, abbreviated to “MDI”, means any of the isomeric forms of diphenylmethane diisocyanate and any desired mixture thereof, in particular diphenylmethane 4,4′-diisocyanate, diphenylmethane 2,4′-diisocyanate, and diphenylmethane 2,2′-diisocyanate.
[0019] A broken line in the formulae in this document always represents the bond between a substituent and the associated molecular moiety.
[0020] The expression “primary hydroxy group” means an OH group bonded to a C atom having two hydrogens.
[0021] The expression “primary amino group” means an NH 2 group bonded to an organic moiety, and the expression “secondary amino group” means an NH group bonded to two organic moieties, which can also together be part of a ring.
[0022] The term “viscosity” in the present document means dynamic viscosity or shear viscosity, defined via the ratio between shear stress and shear rate (velocity gradient) and determined as described in DIN EN ISO 3219.
[0023] The expression “molecular weight” in the present document means the molecular weight (in grams per mole) of a molecule. The expression “average molecular weight” means the number average M n of an oligomeric or polymeric mixture of molecules, usually determined by means of gel permeation chromatography (GPC) against polystyrene as standard.
[0024] The expression “storage-stable” or “storable” is applied to a substance or a composition if, when suitably packaged, it can be stored at room temperature for a relatively long time, for example for at least 3 months up to 6 months or more, and that this storage does not cause its usage properties to change to an extent that is relevant for its use.
[0025] The expression “room temperature means a temperature of about 23° C.
[0026] The first component of the composition includes at least one polymer polyol which is a dispersion of a polymer that is solid at room temperature in a polyether polyol that is liquid at room temperature.
[0027] It is, for example, preferable that the average particle size of the solid polymer is at most 5 μm. It is particularly preferable that the average particle size is, for example, below 2 μm, in particular in the range from 0.1 to 1 μm.
[0028] Suitable polymer polyols are polyether polyols including polymers and/or copolymers of vinylic monomers such as in particular acrylonitrile, styrene, α-methylstyrene,methyl (meth)acrylate or hydroxyethyl (meth)acrylate, and also polyureas/polyhydrazodicarbonamides (PHD) and polyurethanes, where the two phases form a stable, storable dispersion, and the polymer can have been partially grafted onto the polyether polyol, or can have been partially covalently bonded to the polyether polyol.
[0029] Preference is given to polymer polyols where the solid polymer is a copolymer of acrylonitrile and styrene (SAN) or is a polyurea/polyhydrazodicarbonamide (PHD) or is a polyurethane. These polymer polyols are particularly easy to produce, and are storable. Very particular preference is given to SAN. This material is particularly hydrophobic, and is therefore advantageous in combination with isocyanates.
[0030] The polyether polyol of the polymer polyol is, for example, preferably a polyoxyalkylene polyol produced via ring-opening polymerization of oxiranes, in particular ethylene oxide and/or propylene 1,2-oxide, with the aid of a starter molecule having two or more active hydrogen atoms, in particular water, glycols such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, or polypropylene glycols, or triols, in particular glycerol or 1,1,1-trimethylolpropane, or sugar alcohols, in particular sorbitol (D-glucitol), or diphenols, in particular bisphenol A, or amines, in particular ammonia, ethylenediamine or aniline, or a mixture thereof.
[0031] It is particularly preferably a polyoxyalkylene polyol, in particular a polyoxypropylene polyol or an ethylene-oxide-terminated (“EO-end-capped”) polyoxypropylene polyol.
[0032] The molecular weight of the polyether polyol of the polymer polyol is, for example, preferably in the range from 400 to 8000 g/mol, in particular from 1000 to 6000 g/mol.
[0033] The average OH functionality of the polyether polyol of the polymer polyol is, for example, preferably in the range from 1.75 to 3.5, in particular from 2.25 to 3.0.
[0034] It is most preferable that the polyether polyol of the polymer polyol is, for example, an ethylene-oxide-terminated polyoxypropylenetriol with molecular weight in the range from 1000 to 6000 g/mol. This type of polymer polyol has mainly primary hydroxy groups, is relatively hydrophobic, and has OH-functionality greater than 2, thus being particularly suitable for combination with isocyanates.
[0035] The polymer polyol can be composed of any desired combination of the solid polymers mentioned and of the polyether polyols mentioned.
[0036] A very particularly preferred exemplary polymer polyol is an ethylene-oxide-terminated polyoxypropylenetriol with molecular weight in the range from 1000 to 6000 g/mol comprising an SAN polymer.
[0037] The content of solid polymer in the polymer polyol is, for example, preferably in the range from 10 to 50% by weight.
[0038] Preferred polymer polyols are commercially available products which are used mainly for production of flexible polyurethane foams, in particular the SAN polyols Lupranol® 4003/1, Lupranol® 4006/1/SC10, Lupranol® 4006/1/SC15, Lupranol® 4006/1/SC25, Lupranol® 4010/1/SC10, Lupranol® 4010/1/SC15, Lupranol® 4010/1/SC25, Lupranol® 4010/1/SC30, or Lupranol® 4010/1/SC40 (all from BASF), Desmophen® 5027 GT, or Desmophen® 5029 GT (both from Bayer MaterialScience), Voralux® HL106, Voralux® HL108, Voralux® HL109, Voralux® HL120, Voralux® HL400, Voralux® HN360, Voralux® HN370, Voralux® HN380, or Specflex® NC 700 (all from Dow), Caradol® SP27-25, Caradol® SP30-15, Caradol® SP30-45, Caradol® SP37-25, Caradol® SP42-15, Caradol® SP44-10, or Caradol® MD22-40 (all from Shell), and also the PHD polyol Desmophen® 5028 GT (from Bayer MaterialScience).
[0039] Among these, particular preference is given to the SAN polyols, in particular the commercially available products mentioned.
[0040] The first component of the composition moreover includes at least one diol chain extender.
[0041] It is preferable that the diol chain extender is, for example, an aliphatic or cycloaliphatic diol with molecular weight in the range from 60 to 200 g/mol.
[0042] The diol chain extender preferably contains at least one primary hydroxy group.
[0043] Suitable diol chain extenders are selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 1,2-pentanediol, 2,4-pentanediol, 2-methyl-1,4-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,6-hexanediol, 1,2-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,2-octanediol, 3,6-octanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,7-dimethyl-3,6-octanediol, 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol and dipropylene glycol.
[0044] Among these, particular preference is given to products that are liquid at room temperature and have primary OH groups, in particular 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and diethylene glycol.
[0045] 1,4-Butanediol is for example, a most preferred as diol chain extender.
[0046] The quantity of the diol chain extender present in the composition is, for example, preferably such that from 20% to 80%, preferably from 30% to 70%, of the isocyanate groups present can crosslink by way of the diol chain extender.
[0047] The first component of the composition optionally includes other polyols.
[0048] Suitable other exemplary polyols are in particular the following:
polyoxyalkylene polyols, also termed polyether polyols, these being polymerization products of ethylene oxide, propylene 1,2-oxide, butylene 1,2-oxide, or butylene 2,3-oxide, oxetane, tetrahydrofuran, or a mixture thereof, possibly polymerized with the aid of a starter molecule having two or more active hydrogen atoms. Ethylene-oxide-terminated polyoxypropylene polyols are specifically suitable. Polyester polyols, in particular from polycondensation of hydroxycarboxylic acids, and in particular those produced from di- to trihydric, in particular dihydric, alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,12-hydroxystearyl alcohol, 1,4-cyclohexanedimethanol, dimer fatty acid diol (dimer diol), neopentyl glycol hydroxypivalate, glycerol, 1,1,1-trimethylolpropane, or a mixture of the abovementioned alcohols, with organic di- or tricarboxylic acids, in particular dicarboxylic acids, or their anhydrides or esters, particular examples being succinic acid, glutaric acid, adipic acid, trimethyladipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, dimer fatty acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, hexahydrophthalic acid, trimellitic acid or trimellitic anhydride, or a mixture of the abovementioned acids, and also polyester polyols derived from lactones, a particular example being ε-caprolactone, and from starters such as the abovementioned di- or trihydric alcohols.
[0051] Particularly suitable polyester polyols are polyesterdiols.
Polycarbonate polyols as obtainable via reaction, for example, of the abovementioned alcohols, these being those used in the structure of the polyester polyols, with dialkyl carbonates, or with diaryl carbonates or phosgene. Block copolymers which bear at least two hydroxy groups and comprise at least two different blocks with polyether, polyester, and/or polycarbonate structure of the type described above, in particular polyether polyester polyols. Polyacrylate polyols and polymethacrylate polyols. Polyhydroxy-functional fats and oils, for example natural fats and oils, in particular castor oil; or polyols—termed oleochemical polyols—obtained via chemical modification of natural fats and oils, for example the epoxypolyesters/epoxypolyethers obtained via epoxidation of unsaturated oils and subsequent ring-opening with carboxylic acids/alcohols, or polyols obtained via hydroformylation and hydrogenation of unsaturated oils; or polyols obtained from natural fats and oils via degradation processes such as alcoholysis or ozonolysis, and subsequent chemical linkage, for example via transesterification or dimerization, of the resultant degradation products or derivatives thereof. Suitable degradation products of natural fats and oils are in particular fatty acids and fatty alcohols, and also fatty acid esters, in particular the methyl esters (FAME), where these can by way of example be derivatized via hydroformylation and hydrogenation to give hydroxy fatty acid esters. Polyhydrocarbon polyols, also termed oligohydrocarbonols, for example polyhydroxy-functional polyolefins, polyisobutylenes, polyisoprenes; polyhydroxy-functional ethylene-propylene, ethylene-butylene, or ethylene-propylene-diene copolymers, for example those produced by Kraton Polymers; polyhydroxy-functional polymers of dienes, in particular of 1,3-butadiene, where these can in particular also derive from anionic polymerization; polyhydroxy-functional copolymers of dienes such as 1,3-butadiene, or of diene mixtures and vinyl monomers such as styrene, acrylonitrile, vinyl chloride, vinyl acetate, vinyl alcohol, isobutylene, and isoprene, examples being polyhydroxy-functional acrylonitrile/butadiene copolymers of the type that can be produced by way of example from epoxides or from aminoalcohols and from carboxy-terminated acrylonitrile/butadiene copolymers (obtainable commercially by way of example as Hypro® (previously Hycar®) CTBN and CTBNX and ETBN from Nanoresins AG, Germany or Emerald Performance Materials LLC); and also hydrogenated polyhydroxy-functional polymers or copolymers of dienes.
[0057] The average molecular weight of the abovementioned polyols is, for example, preferably in the range from 400 to 8000 g/mol, in particular from 1000 to 6000 g/mol, their average OH-functionality being in the range from 1.6 to 4.
[0058] The composition preferably includes at least one other polyol which is a polyether polyol or a poly(meth)acrylate polyol, or a polyhydroxy-functional fat or oil.
[0059] It is particularly preferable that the composition includes, as other polyol, an ethylene-oxide-terminated polyoxypropylenedi- or triol and/or castor oil.
[0060] It is preferable that the proportion of solid polymer from the polymer polyol, based on the entirety of polymer polyol and optionally present other polyols, is in the range from for example, 5 to 30% by weight, in particular from 8 to 25% by weight. This type of composition is easy to use and has high strength.
[0061] The second component of the composition includes diphenylmethane diisocyanate (MDI). The following are preferred as MDI: diphenylmethane 4,4′-diisocyanate (4,4′-MDI), diphenylmethane 2,4′-diisocyanate (2,4′-MDI) and/or diphenylmethane 2,2′-diisocyanate (2,2′-MDI). Particular preference is given to 4,4′-MDI. This permits achievement of particularly high strength values.
[0062] The content of monomeric diphenylmethane diisocyanate in the second component is, for example, preferably in the range from 20 to 100% by weight, particularly preferably from 40 to 100% by weight, in particular from 60 to 100% by weight.
[0063] The MDI is preferably present in a form that is liquid at room temperature, with high content of 4,4′-MDI. The material known as “liquid MDI” is either 4,4′-MDI liquefied via partial chemical modification—in particular carbodiimidization/uretonimine formation or adduct formation with polyols—or is a mixture, specifically produced via blending or resulting from the production process, of 4,4′-MDI with other MDI isomers (2,4′-MDI and/or 2,2′-MDI), MDI oligomers, or MDI homologs.
[0064] Preference is given to monomeric MDI products with a relatively high proportion of 2,4′-MDI, for example the commercially obtainable products Desmodur® 2424 (from Bayer MaterialScience) or Lupranat® MI (from BASF), and also mixtures of monomeric MDI with MDI homologs with a small proportion of homologs, for example the commercially obtainable products Desmodur® VL50 (from Bayer MaterialScience) or Voranate® M 2940 (from Dow), and also partially carbodiimidized 4,4′-MDI, for example the commercially obtainable products Desmodur® CD (from Bayer MaterialScience), Lupranat® MM 103 (from BASF), Isonate® M 143 or Isonate® M 309 (both from Dow), Suprasec® 2020 or Suprasec® 2388 (both from Huntsman), and also MDI products known as quasi-prepolymers, involving some proportion of adducts with polyols/polyhydric alcohols such as trimethylolpropane, for example the commercially obtainable products Desmodur® VH20N, Desmodur® E21, Desmodur® E210 (all from Bayer MaterialScience), Lupranat® MP 102 (from BASF), Echelon™ MP 107, Echelon™ MP 106 or Echelon™ MP 102 (all from Dow). The isocyanate content of these quasi-prepolymers is preferably in the range from 10 to 30% by weight, in particular from 15 to 28% by weight.
[0065] It is particularly preferable that the MDI takes the form of partially carbodiimidized 4,4′-MDI and/or takes the form of 4,4′-MDI involving some proportion of adducts with polyols/polyhydric alcohols.
[0066] It is preferable that the isocyanate content of the second component of the composition is, for example, in the range from 10 to 33.6% by weight, particularly from 15 to 33.6% by weight, in particular from 20 to 33.6% by weight. This type of second component can have very low viscosity, and can successfully dilute the first component, so that the composition is very easy to use.
[0067] The composition moreover includes at least one aldimine of the formula (I).
[0000]
[0068] It is preferable that A is a moiety selected from the group consisting of 2-methyl-1,5-pentylene; 1,6-hexylene; 2,2(4),4-trimethyl-1,6-hexamethylene; 1,8-octylene; 1,10-decylene; 1,12-dodecylene; (1,5,5-trimethylcyclohexan-1-yl)methane-1,3; 1,3-cyclohexylenebis(methylene); 1,4-cyclohexylenebis(methylene); 1,3-phenylenebis(methylene); 2- and/or 4-methyl-1,3-cyclohexylene; 3-oxa-1,5-pentylene; 3,6-dioxa-1,8-octylene; 4,7-dioxa-1,10-decylene; α,ω-polyoxypropylene with molecular weight in the range from 170 to 450 g/mol; and trimethylolpropane-started tris(ω-polyoxypropylene) with average molecular weight in the range from 330 to 450 g/mol.
[0069] A is particularly preferably 1,6-hexylene; (1,5,5-trimethylcyclohexan-1-yl)methane-1,3; 3-oxa-1,5-pentylene; α,ω-polyoxypropylene with average molecular weight about 200 g/mol, or trimethylolpropane-started tris(w-polyoxypropylene) with average molecular weight about 390 g/mol.
[0070] A is most preferably 1,6-hexylene or (1,5,5-trimethylcyclohexan-1-yl)methane-1,3. Particularly high strength values are achieved with 1,6-hexylene, and particularly long open times are achieved with (1,5,5-trimethylcyclohexan-1-yl)methane-1,3.
[0071] It is preferable that R 1 and R 2 are respectively methyl.
[0072] It is preferable that R 3 is hydrogen.
[0073] It is preferable that R 4 is a linear alkyl moiety having from 11 to 20 C atoms, in particular a linear alkyl moiety having 11 C atoms.
[0074] These aldimines are practically odorless before, during and after hydrolytic activation and crosslinking with isocyanates.
[0075] It is preferable that m is 0 and that n is 2 or 3, in particular 2.
[0076] In the event that m is 1, it is preferable that n is 1.
[0077] In the event that m is 1, it is preferable that X is O.
[0078] An aldimine of the formula (I) is in particular obtainable from the condensation reaction of at least one primary amine of the formula (II) with at least one aldehyde of the formula (III).
[0000]
[0079] The definitions of m, n, A, X, R 1 , R 2 , R 3 , and R 4 in the formulae (II) and (III) are those previously mentioned.
[0080] The quantity of the aldehyde of the formula (III) used in this condensation reaction is preferably stoichiometric or more than stoichiometric, based on the primary amino groups of the amine of the formula (II). The reaction is advantageously carried out at a temperature in the exemplary range from 15 to 120° C., optionally in the presence of a solvent, or else without solvent. The water liberated is preferably removed, for example azeotropically by means of a suitable solvent, or directly from the reaction mixture via application of vacuum.
[0081] Suitable amines of the formula (II) are aliphatic, cycloaliphatic and aromatic amines, in particular the following:
aminoalcohols such as in particular 2-aminoethanol, 2-amino-1-propanol, 1-amino-2-propanol, 3-amino-1-propanol, 4-amino-1-butanol, 4-amino-2-butanol, 2-amino-2-methylpropanol, 5-amino-1-pentanol, 6-amino-1-hexanol, 7-amino-1-heptanol, 8-amino-1-octanol, 10-amino-1-decanol, 12-amino-1-dodecanol, 4-(2-aminoethyl)-2-hydroxyethylbenzene, 3-aminomethyl-3,5,5-trimethylcyclohexanol, compounds bearing one primary amino group and deriving from glycols, for example from diethylene glycol, dipropylene glycol, or dibutylene glycol, or from higher oligomers of these glycols, in particular 2-(2-aminoethoxy)ethanol, 2-(2-(2-aminoethoxy)ethoxy)ethanol, or products from monocyanoethylation and subsequent hydrogenation of glycols, in particular 3-(2-hydroxyethoxy)propylamine, 3-(2-(2-hydroxyethoxy)ethoxy)propylamine, or 3-(6-hydroxyhexyloxy)propylamine; primary-secondary amines such as in particular N-methyl-1,2-ethanediamine, N-ethyl-1,2-ethanediamine, N-butyl-1,2-ethanediamine, N-hexyl-1,2-ethanediamine, N-(2-ethylhexyl)-1,2-ethanediamine, N-cyclohexyl-1,2-ethanediamine, 4-aminomethylpiperidine, 3-(4-aminobutyl)piperidine, N-methyl-1,3-propanediamine, N-ethyl-1,3-propanediamine, N-butyl-1,3-propanediamine, N-hexyl-1,3-propanediamine, N-(2-ethylhexyl)-1,3-propanediamine, N-dodecyl-1,3-propanediamine, N-cyclohexyl-1,3-propanediamine, 3-methylamino-1-pentylamine, 3-ethylamino-1-pentylamine, 3-butylamino-1-pentylamine, 3-hexylamino-1-pentylamine, 3-(2-ethylhexyl)amino-1-pentylamine, 3-dodecylamino-1-pentylamine, 3-cyclohexylamino-1-pentylamine, diethylenetriamine (DETA), dipropylenetriamine (DPTA), N-(2-aminoethyl)-1,3-propanediamine (N3-amine), bishexamethylenetriamine (BHMT), N3-(3-aminopentyl)-1,3-pentanediamine, N5-(3-aminopropyl)-2-methyl-1,5-pentanediamine, or N5-(3-amino-1-ethylpropyl)-2-methyl-1,5-pentanediamine; primary di- and triamines such as in particular ethylenediamine, 1,2- and 1,3-propanediamine, 2-methyl-1,2-propanediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-pentanediamine (DAMP), 1,5-pentanediamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine), 1,6-hexanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine (TMD), 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecandiamine, 1,2-, 1,3- and 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3-ethylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, bis(4-amino-3-ethyl-5-methylcyclohexyl)methane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (=isophoronediamine), 2- and 4-methyl-1,3-diaminocyclohexane and mixtures thereof, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 ]decane, 1,4-diamino-2,2,6-trimethylcyclohexane (TMCDA), 1,8-menthanediamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3-bis(aminomethyl)benzene, 1,4-bis(aminomethyl)benzene, bis(2-aminoethyl) ether, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12-diamine, 5,8-dioxadodecane-3,10-diamine, 4,7,10-trioxatridecane-1,13-diamine, cycloaliphatic diamines which contain ether groups and derive from propoxylation and subsequent amination of 1,4-dimethylolcyclohexane, obtainable in particular as Jeffamine® RFD-270 (from Huntsman), polyoxyalkyleneamines with average molecular weight in the range from 200 to 500 g/mol, as are obtainable commercially by way of example with trademark Jeffamine® (from Huntsman), polyetheramines (from BASF), and PC Amine® (from Nitroil), characterized in that they bear 2-aminopropyl or 2-aminobutyl end groups, in particular Jeffamine® D-230, Jeffamine® D-400, Jeffamine® XTJ-582, Jeffamine® HK-511, Jeffamine® T-403, or Jeffamine® XTJ-566 (all from Huntsman), or products analogous thereto from BASF and Nitroil; aromatic polyamines such as in particular 1,3-phenylenediamine, 1,4-phenylenediamine, 4,4′-, 2,4′, and 2,2′-diaminodiphenylmethane, 2,4- and 2,6-tolylenediamine, mixtures of 3,5-diethyl-2,4- and -2,6-tolylenediamine (DETDA), 3,5-dimethylthio-2,4- and -2,6-tolylenediamine, 3,3′,5,5′-tetraethyl-4,4′-diaminodiphenylmethane (M-DEA), 3,3′-diisopropyl-5,5′-dimethyl-4,4′-diaminodiphenylmethane (M-MIPA) or 3,3′,5,5′-tetraisopropyl-4,4′-diaminodiphenylmethane (M-DIPA).
[0086] Preferred amines of the formula (II) are selected from the group consisting of 1,5-diamino-2-methylpentane, 1,6-hexanediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 1,8-octanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)benzene, 2- and/or 4-methyl-1,3-diaminocyclohexane, 2-(2-aminoethoxy)ethanol, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, and polyoxypropyleneamines with average molecular weight in the range from 200 to 500 g/mol, in particular Jeffamine® D-230, Jeffamine® D-400, and Jeffamine® T-403.
[0087] Preference is given among these to 1,6-hexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 2-(2-am inoethoxy)ethanol, polyoxypropylenediamine with average molecular weight about 230 g/mol, and polyoxypropylenetriamine with average molecular weight about 440 g/mol.
[0088] Most preference is given to 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane.
[0089] A particularly suitable aldehyde of the formula (III) is 2,2-dimethyl-3-lauroyloxypropanal.
[0090] Suitable aldimines of the formula (I) are in particular selected from the group consisting of N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)hexamethylene-1,6-diamine, N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine, N-2,2-dimethyl-3-lauroyloxypropylidene-2-(2-aminoethoxy)ethanol, N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)polyoxypropylenediamine with average molecular weight in the range from 710 to 810 g/mol, and N, N′, N″-tris(2,2-dimethyl-3-lauroyloxypropylidene)polyoxypropylenetriamine with average molecular weight in the range from 1190 to 1290 g/mol.
[0091] Particularly suitable aldimines of the formula (I) are N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)hexamethylene-1,6-diamine and/or N, N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine. These aldimines give compositions with particularly high strength values.
[0092] N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)hexamethylene-1,6-diamine tends to give very particularly high strength values, and N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine achieves particularly long open times.
[0093] The aldimine of the formula (I) can be present as constituent of the first component or as constituent of the second component, or in both components. It is preferably a constituent of the first component.
[0094] In the event that m is 1, the aldimine of the formula (I) is either a constituent of the first component or is present in a form reacted with MDI in the second component, for example, in the form depicted in the following formula:
[0000]
[0095] The quantity of the aldimine of the formula (I) present in the composition is, for example, preferably such that from 5% to 50%, preferably from 10% to 30%, of the isocyanate groups present can crosslink by way of the aldimine of the formula (I).
[0096] The composition preferably additionally comprises at least one catalyst for the reaction of hydroxy groups with isocyanate groups.
[0097] Compounds suitable for this purpose are organotin(IV) compounds such as in particular dibutyltin diacetate, dibutyltin dilaurate, dimethyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, or dioctyltin dilaurate.
[0098] However, preference is given to compounds of iron(III), bismuth(III), and zirconium(IV), particularly complex compounds of iron(III), bismuth(III), and zirconium(IV). These complex compounds can be produced by known processes starting from, for example, iron(III) oxide, bismuth(III) oxide, or zirconium(IV) oxide. With these complex compounds, the composition cures rapidly and substantially without formation of bubbles, to give a high-strength non-tacky material.
[0099] It is particularly preferable that at least one of the two components of the composition includes a zirconium(IV) compound, in particular a zirconium(IV) complex compound. With zirconium(IV) compounds as catalyst, the composition has long pot life and hardens rapidly.
[0100] Suitable ligands for complex compounds of iron(III), bismuth(III), or zirconium(IV) are for example:
alcoholates, in particular methanolate, ethanolate, propanolate, isopropanolate, butanolate, tert-butanolate, isobutanolate, pentanolate, neopentanolate, hexanolate, or octanolate; carboxylates, in particular formiate, acetate, propionate, butanoate, isobutanoate, pentanoate, hexanoate, cyclohexanoate, heptanoate, octanoate, 2-ethyl hexanoate, nonanoate, decanoate, neodecanoate, undecanoate, dodecanoate, lactate, oleate, citrate, benzoate, salicylate, or phenylacetate; 1,3-diketonates, in particular acetylacetonate (2,4-pentanedionate), 2,2,6,6-tetramethyl-3,5-heptanedionate, 1,3-diphenyl-1,3-propanedionate (dibenzoyl-methane), 1-phenyl-1,3-butanedionate, or 2-acetylcyclohexanonate; oxinate; 1,3-ketoesterates, in particular methyl acetoacetate, ethyl acetoacetate, ethyl 2-methylacetoacetate, ethyl 2-ethylacetoacetate, ethyl 2-hexylacetoacetate, ethyl 2-phenylacetoacetate, propyl acetoacetate, isopropyl acetoacetate, butyl acetoacetate, tert-butyl acetoacetate, ethyl 3-oxovalerate, ethyl 3-oxohexanoate, or ethyl 2-oxocyclohexanecarboxylate; and 1,3-ketoamidates, in particular N,N-diethyl-3-oxobutanamidate, N,N-dibutyl-3-oxo-butanamidate, N,N-bis(2-ethylhexyl)-3-oxobutanamidate, N,N-bis(2-methoxyethyl)-3-oxo-butanamidate, N,N-dibutyl-3-oxo-heptanamidate, N,N-bis(2-methoxyethyl)-3-oxo-heptanamidate, N,N-bis(2-ethylhexyl)-2-oxocyclopentanecarboxamidate, N,N-dibutyl-3-oxo-3-phenylpropanamidate, N,N-bis(2-methoxyethyl)-3-oxo-3-phenylpropanamidate, or N-polyoxyalkylene-1,3-ketoamidate such as in particular acetoamidates of polyoxyalkyleneamines having one, two, or three amino groups and molecular weight up to 5000 g/mol, in particular the following products obtainable with trademark Jeffamine® from Huntsman SD-231, SD-401, SD-2001, ST-404, D-230, D-400, D-2000, T-403, M-600, and XTJ-581.
[0107] Particularly preferred zirconium(IV) complex compounds are selected from the group consisting of zirconium(IV) tetrakis(acetate), zirconium(IV) tetrakis(octanoate), zirconium(IV) tetrakis(2-ethylhexanoate), zirconium(IV) tetrakis(neodecanoate), zirconium(IV) tetrakis(acetylacetonate), zirconium(IV) tetrakis(1,3-diphenylpropane-1,3-dionate), zirconium(IV) tetrakis(ethylacetoacetate), zirconium(IV) tetrakis(N,N-diethyl-3-oxobutanamidate), and zirconium(IV) complex compounds having various abovementioned ligands.
[0108] The catalyst for the reaction of hydroxy groups with isocyanate groups can be present as constituent of the first and/or of the second component. It is preferably a constituent of the first component.
[0109] The composition preferably additionally includes at least one catalyst for the hydrolysis of the aldimine. Compounds suitable for this purpose are in particular organic acids, for example carboxylic acids such as benzoic acid, salicylic acid, or 2-nitrobenzoic acid, organic carboxylic anhydrides such as phthalic anhydride, hexahydrophthalic anhydride, and hexahydromethylphthalic anhydride, organic sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid, or 4-dodecylbenzenesulfonic acid, sulfonic esters, other organic or inorganic acids, silyl esters of organic carboxylic acids, or mixtures of the abovementioned acids and esters. Particular preference is given to carboxylic acids, in particular aromatic carboxylic acids such as benzoic acid, 2-nitrobenzoic acid, and in particular salicylic acid.
[0110] The catalyst for the hydrolysis of the aldimine is preferably a constituent of the first component.
[0111] The composition preferably additionally includes other additions commonly used for polyurethane liquid membranes. In particular, the following auxiliaries and additional substances can be present.
inorganic and organic fillers, in particular ground or precipitated calcium carbonates which optionally have been coated with fatty acids, in particular with stearates, barite (heavy spar), powdered quartz, quartz sand, dolomite, wollastonite, kaolin, calcined kaolin, phyllosilicates such as mica or talc, zeolites, aluminum hydroxides, magnesium hydroxide, silicas, inclusive of fine-particle silicas from pyrolysis processes, cements, gypsum, fly ash, industrially produced carbon blacks, graphite, metal powders such as aluminum, copper, iron, silver, or steel, PVC powder, or hollow spheres; fibers, in particular glass fibers, carbon fibers, metal fibers, ceramic fibers, synthetic fibers such as polyamide fibers or polyethylene fibers, or natural fibers such as wool, cellulose, hemp, or sisal; dyes; inorganic or organic pigments, for example titanium dioxide, chromium oxide, or iron oxides; other catalysts which accelerate the reaction of the isocyanate groups, in particular compounds of zinc, manganese, chromium, cobalt, copper, nickel, molybdenum, lead, cadmium, mercury, antimony, vanadium, titanium, and potassium, in particular zinc(II) acetate, zinc(II) 2-ethylhexanoate, zinc(II) laurate, zinc(II) acetylacetonate, cobalt(II) 2-ethylhexanoate, copper(II) 2-ethylhexanoate, nickel(II) naphthenate, aluminum lactate, aluminum oleate, diisopropoxytitanium bis(ethylacetoacetate), and potassium acetate; compounds comprising tertiary amino groups, in particular 2,2′-dimorpholino-diethyl ether, N-ethyldiisopropylamine, N,N,N′,N′-tetramethylalkylenediamine, pentamethylalkylenetriamine, and higher homologs thereof, bis(N,N-diethylaminoethyl) adipate, tris(3-dimethylaminopropyl)amine, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), N-alkylmorpholines, N,N′-dimethylpiperazines; nitrogen-aromatic compounds such as 4-dimethylaminopyridine, N-methylimidazole, N-vinylimidazole, or 1,2-dimethylimidazole; organic ammonium compounds such as benzyltrimethylammonium hydroxide or alkoxylated tertiary amines; compounds known as “delayed-action” catalysts, which are modified forms of known metal catalysts or of known amine catalysts; and also combinations of the compounds mentioned, in particular of metal compounds and of tertiary amines; additives such as in particular wetting agents, leveling agents, antifoams, deaerating agents, stabilizers with respect to oxidation, heat, light, and UV radiation, biocides, desiccants such as in particular molecular sieve powder, adhesion promoters such as in particular organoalkoxysilanes, rheology modifiers such as in particular phyllosilicates, hydrogenated castor oil, polyamides, polyamide waxes, polyurethanes, urea compounds, fumed silicas, hydrophobically modified polyoxyethylenes, or derivatives of castor oil; plasticizers, in particular phthalates, trimellitates, adipates, sebacates, azelates, citrates, benzoates, acetylated glycerol, or monoglycerides, or hydrocarbon resins, or diesters of ortho-cyclohexanedicarboxylic acid; flame-retardant substances, in particular the abovementioned fillers aluminum hydroxide and magnesium hydroxide, and also in particular organic phosphoric esters such as in particular triethyl phosphate, tricresyl phosphate, triphenyl phosphate, diphenyl cresyl phosphate, isodecyl diphenyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(2-ethylhexyl) phosphate, tris(chloroisopropyl) phosphate, tris(chloropropyl) phosphate, isopropylated triphenyl phosphate, mono-, bis-, and tris(isopropylphenyl) phosphates having different degrees of isopropylation, resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), or ammonium polyphosphates, melamine and melamine derivatives such as phosphates or isocyanurates, expanding graphites, zinc borates, or antimony trioxide.
[0120] These additions can be present as constituent of the first or of the second component. Substances reactive with isocyanate groups are preferably a constituent of the first component. It can be advisable to dry certain constituents chemically or physically before mixing into the respective component.
[0121] The composition is preferably in essence free from volatile solvents. In particular, it includes, for example at most 1% by weight, preferably at most 0.5% by weight, of volatile solvents, particularly preferably being entirely free from volatile solvents. The expression “volatile solvent” here means a liquid organic compound with vapor pressure at least 0.01 kPa at a temperature of 293.14 K which is not reactive toward isocyanates.
[0122] The composition preferably includes at least one inorganic filler.
[0123] The ratio of the groups reactive toward isocyanate groups, particular examples being hydroxy groups, primary and secondary amino groups, and aldimino groups, to the isocyanate groups in the composition is suitably in the exemplar range from 0.5 to 1.1, preferably in the range from 0.7 to 1.05, particularly preferably in the range from 0.8 to 1.0, in particular about 0.95.
[0124] A preferred first component includes:
at least one polymer polyol, at least one diol chain extender, at least one aldimine of the formula (I), and optionally other polyols,
where the proportion of solid polymer from the polymer polyol, based on the entirety of polymer polyol and other polyols, is in the range from 5 to 30% by weight, in particular from 8 to 25% by weight.
[0129] he quantity present here of the polymer polyol, of the diol chain extender, of the aldimine of the formula (I), and of other polyols is such that of the total number of their groups reactive toward isocyanates, for example:
from 10% to 50%, in particular from 20% to 40%, derive from the polymer polyol and from other polyols optionally present, from 20% to 80%, in particular from 40% to 70%, derive from the diol chain extender, and from 5% to 50%, in particular from 10% to 30%, derive from the aldimine of the formula (I).
[0133] It is preferable that the viscosity of the first component of the composition at 25° C. is in the exemplary range from 1 to 6 Pa.s, preferably from 1 to 4 Pas.
[0134] The first and the second components of the composition are produced separately from one another. The constituents of the respective component here are mixed with one another with exclusion of moisture in such a way as to produce a macroscopically homogeneous liquid. Each component is stored in a separate vessel that prevents ingress of moisture. A suitable vessel is in particular a full-aperture drum or other drum, a container, a bucket, a can, a bag, a canister, or a bottle. The components are storage-stable, and this means that they can be stored in the respective vessel for several months or for up to a year or longer before they are used, without any change of their properties to an extent that is relevant for their use.
[0135] For use of the composition, the two components are mixed with one another just before, or during, application. The mixing ratio is preferably selected in such a way that the ratio of the groups reactive toward isocyanates to the isocyanate groups is suitable, as described above. An exemplary mixing ratio of the first to the second component in parts by weight is in the range from about 1:1 to 20:1, in particular 2:1 to 10:1.
[0136] The mixing of the two components is achieved by using a suitable mixer, for example a twin-shaft mixer, where the individual components are suitably subjected to preliminary processing in the correct mixing ratio. It is equally possible to carry out continuous processing in a machine with use of a two-component metering system, with static or dynamic mixing of the components. Care should be taken to maximize homogeneity of mixing of the two components during the mixing procedure. If mixing is inadequate, local deviations from the advantageous mixing ratio occur, and this can result in impairment of mechanical properties, and/or formation of bubbles. If mixing is carried out before application, it is necessary to ensure that the period between mixing of the components and application is not excessive, because an excessive period can here can lead to problems, for example poor flow, or retarded or inadequate development of adhesion to the substrate. The mixing is in particular achieved at ambient temperature, which is for example in the range of about 5 to 50° C., preferably about 10 to 35° C.
[0137] Hardening via chemical reaction begins with the mixing of the two components. Hydroxy groups and primary and secondary amino groups that are present react here with isocyanate groups that are present. Aldimino groups react with isocyanate groups that are present as soon as they come into contact with moisture. The water required for the hydrolysis of the aldimino groups here can at least to some extent be present in the composition or diffuses from the surroundings in the form of moisture from the environment, in particular in the form of humidity or substrate moisture, into the mixed composition. Excess isocyanate groups react with moisture that is present. These reactions cause curing of the composition to give a robust material. This procedure is also termed crosslinking. During and after hardening, aldehyde liberated from the aldimino groups remains in the composition, where it acts as odorless substance with a degree of plasticizing effect. Because it has excellent compatibility in the composition, it exhibits no tendency of any kind toward separation or migration.
[0138] The present disclosure moreover provides a hardened composition obtained from a composition as described above after mixing of the two components and hardening of these.
[0139] The freshly mixed, still liquid composition is applied as coating, within its open time, to a level or slightly inclined area, for example by pouring onto a substrate followed by distribution over an area until the desired layer thickness has been reached, for example by use of a roller, a bar, a toothed trowel, or a spatula.
[0140] The expression “open time” or “pot life” here means the period between mixing of the components and the end of suitability of the composition for use. An exemplary criterion for the end of pot life can be doubling of viscosity.
[0141] It is preferable that the viscosity of the composition at 25° C. one minute after mixing is in the exemplary range from 0.5 to 2 Pa·s, preferably from 0.5 to 1.5 Pa·s. This permits very successful use of the composition as liquid membrane. It is preferable that the composition is self-leveling, i.e. that after application by means of a roller, toothed trowel, toothed roller, or the like it flows spontaneously to give a level surface.
[0142] A single operation can apply a layer thickness in the exemplar range from 0.5 to 3 mm, in particular from 1.0 to 2.5 mm.
[0143] The composition can be applied to various substrates, and on hardening forms a resilient layer providing static and dynamic bridging over cracks. It protects the underlying material from ingress of water, acids, alkalis, oil, gasoline, de-icing salts, etc., and also from abrasion and wear, and can additionally serve to improve aesthetics.
[0144] The composition described can be applied in one or more layers. It is for example, applied in one layer. One or more topcoats can be applied to the composition described. It is preferable to apply a sealing system as uppermost or final layer.
[0145] The expression “sealing system” here means a transparent or pigmented, high-quality coating which is applied as uppermost thin layer to another coating. It protects, and improves the quality of, the surface of the latter, and seals pores therein. An exemplary layer thickness here in the dry state is in the range from 0.03 to 0.3 mm.
[0146] The sealing system provides additional protection from UV light, oxidation, or microbial colonization, provides possibilities for esthetic design, protects the coating from mechanical damage, and/or prevents soiling, and/or serves for the fixing of aggregates scattered into the material.
[0147] Aggregates such as in particular quartz sand can be scattered into the composition just after application. To this end, quartz sand is scattered into the composition which has been applied to an area but remains liquid, in such a way that after hardening said sand adheres at least to some extent to the hardened composition or has been bonded at least to some extent therein. An excess of, or a defined quantity of, quartz sand can be scattered into the material. If an excess of sand is used, sand not adhering to the composition is removed after hardening.
[0148] The composition can be used for the protection of floors, in particular as coating on balconies, terraces, bridges, parking lots, or other outdoor areas, or for the sealing of roofs, in particular flat roofs or slightly inclined roof areas or roof gardens, or in the interior of buildings for waterproofing, for example under tiles or ceramic panels in wetrooms or kitchens, or as floorcovering in kitchens, industrial buildings or production areas, or as seal in collection troughs of any type, or in conduits or ducts, or waste-water treatment systems, or else as casting composition for cavity sealing, as seam seal, or as protective coating for, by way of example, pipes. It can also be used for repair purposes as seal or coating, for example for leaking roof membranes or for floorcoverings that are no longer functional, or in particular as repair composition for high-reactivity spray seals.
[0149] A preferred use is the use in a floor-coating system containing:
optionally a primer and/or a priming coat, and/or a repair composition or leveling composition, at least one layer of the composition described, onto which a defined quantity of, or an excess of, quartz sand or other aggregates can have been scattered, optionally a topcoat, onto which a defined quantity of, or an excess of, quartz sand or other aggregates can have been scattered, and a sealing system.
It is preferable that quartz sand has been scattered onto one of the layers mentioned. This floor-coating system is particularly suitable for floors that can withstand pedestrian traffic, for example those on parking lots, balconies, terraces, or bridges.
[0154] Another preferred use is the use in a roof-sealing system including:
optionally a primer and/or a priming coat, and/or a repair composition or leveling composition, at least one layer of thickness from 0.5 to 5 mm of the composition described, optionally a topcoat, and optionally a sealing system.
This roof-seal system is particularly suitable for the sealing of flat or slightly inclined roofs, and for the repair of existing roof seals of any type which have become damaged.
[0159] Suitable substrates to which the composition can be applied are for example:
foamed concrete or other concrete, mortar, brick, roof tile, slate, gypsum plaster, anhydrite, or natural stone such as granite or marble; composition intended for repair or leveling and based on PCC (polymer-modified cement mortar) or on ECC (epoxy-resin-modified cement mortar); metals and alloys such as aluminum, copper, iron, steel, nonferrous metals, inclusive of surface-enhanced metals, and alloys, for example galvanized or chromed metals; asphalt or bitumen; plastics such as PVC, ABS, PC, PA, polyester, PMMA, SAN, epoxy resins, phenolic resins, PUR, POM, PO, PE, PP, EPM, or EPDM, in each case untreated or surface-treated by use of plasma, corona, or flame; in particular PVC membranes, PO (FPO, TPO) membranes, or EPDM membranes; insulation foams, in particular made of EPS, XPS, PUR, PIR, rock wool, or glass wool, or of foamed glass; coated substrates such as lacquered tiles, coated concrete, or powder-coated metals.
[0167] The substrates can, if necessary, be pretreated before application of the composition, for example by physical and/or chemical cleaning processes, for example grinding, sandblasting, shotblasting, brushing, suction cleaning, or blow cleaning, or high- or very-high-pressure water jets, and/or via treatment with cleaners or solvents, and/or application of an adhesion promoter, an adhesion-promoter solution, or a primer.
[0168] Application and hardening produces an item which has been coated or sealed with a composition of the present disclosure. The article is in particular construction work, in particular construction work associated with structural or civil engineering, or is an industrially manufactured product, for example a pipe.
[0169] The composition described features advantageous properties. It is solvent-free and has little odor, and is free from volatile monomeric isocyanates. By virtue of its low viscosity and long open time, it can be used with excellent results in manual applications, and is fully leveling when used as surface coating. It cures rapidly and without difficulty under a wide range of conditions in respect of temperature and moisture, producing a resilient material with high strength, extensibility, and tear strength, with moderate modulus of elasticity, and it has excellent weathering resistance. The composition is therefore particularly suitable as liquid membrane for the sealing of floors and roofs in construction work or for the repair of sealing membranes and spray coatings.
Examples
[0170] Embodiments are listed below with the intention of providing a more detailed explanation of embodiments described herein. The invention is not, of course, restricted to these embodiments that are described.
[0171] 1. Commercially Available Substances Used:
[0000]
Lupranol ® 4003/1
EO-end-capped polyoxypropylenetriol with 45% by
weight of grafted SAN polymer, OH number 20.0 mg
KOH/g (from BASF)
Desmophen ® 5028 GT
EO-end-capped polyoxypropylenetriol with 20% by
weight of PHD polymer, OH number 28.5 mg KOH/g
(from Bayer MaterialScience)
Voranol ® CP 4755
EO-end-capped polyoxypropylenetriol, OH number
34.7 mg KOH/g (from Dow)
Castor oil
OH number 165 mg KOH/g (from Alberdingk Boley)
Isonate ® M 143
Modified diphenylmethane 4,4′-diisocyanate comprising
MDI-carbodiimide adducts, liquid at room temperature,
NCO content 29.4% by weight (from Dow)
Desmodur ® VH 20 N
Modified diphenylmethane 4,4′-diisocyanate comprising
MDI-carbodiimide adduct, reacted with a small quantity
of polyol, liquid at room temperature; NCO content
24.5% by weight (from Bayer MaterialScience)
Powdered quartz
Sikron ® SF 600 (from Quarzwerke GmbH)
Zeolite paste
3Å molecular sieve powder (from Zeochem), 50% by
weight in castor oil
K-Kat ® A-209
Zirconium chelate complex in reactive diluents and tert-
butyl acetate, zirconium content 3.5% by weight (from
King Industries)
DBTDL
Dibutyltin dilaurate (from Sigma Aldrich)
[0172] 2. Aldimines Used:
[0173] Amine content (total content of free and blocked amino groups inclusive of aldimino groups) was determined by means of titration (with 0.1N HClO 4 in acetic acid with crystal violet), and is stated in mmol of N/g.
[0174] Aldimine 1: N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine
[0175] 598 g (2.1 mol) of 2,2-dimethyl-3-lauroyloxypropanal were used as initial charge in a round-bottomed flask under nitrogen. 170.3 g (1 mmol) of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (Vestamin® IPD from Evonik) were added, with stirring, and then the volatile constituents were removed at 80° C. at 10 mbar. This gave 732 g of an almost colorless liquid with amine content 2.73 mmol of N/g, corresponding to a calculated equivalent weight of about 367 g/eq.
[0176] Aldimine 2: N,N′-bis(2,2-dimethyl-3-lauroyloxypropylidene)hexamethylene-1,6-diamine 622 g (2.2 mmol) of 2,2-dimethyl-3-lauroyloxypropanal and 166.0 g (1 mol) of hexamethylene-1,6-diamine solution (70% by weight in water) were reacted as described for aldimine 1. This gave 702 g of an almost colorless liquid with amine content 2.98 mmol of N/g, corresponding to a calculated equivalent weight of about 336 g/eq.
[0177] 3. Production of Polyurethane Liquid Membranes
[0178] For each liquid membrane, the stated quantities (in parts by weight) of the ingredients stated in tables 1 to 6 of the first component (“component 1”) were processed by means of a centrifugal mixer (SpeedMixer™ DAC 150, FlackTek Inc.) with exclusion of moisture to give a homogeneous liquid, and stored. The quantity stated in tables 1 to 6 of the second component was then added to the first component, and the two components were processed for 3 minutes by means of the centrifugal mixer, with exclusion of moisture, to give a homogeneous liquid, which was immediately tested as follows:
[0179] Viscosity was measured in a thermostat-controlled Rheotec RC30 cone-on-plate viscometer (cone diameter 50 mm, cone angle 1°, cone-tip-to-plate distance 0.05 mm, shear rate 10 s −1 ).
[0180] Pot life was determined by using a spatula to assess the mobility of 20 grams of the mixed liquid membrane at regular intervals. The pot life value was read when the liquid membrane became too thick for practical use.
[0181] Flow-table value was determined by casting 80 g of the mixed liquid membrane onto a PTFE-coated membrane immediately after mixing of the two components, and measuring the average diameter of the composition after 24 h.
[0182] For determination of mechanical properties, the liquid membrane was cast onto a PTFE-coated membrane to give a membrane of thickness 2 mm, the latter was stored for 14 days under standard conditions of temperature and humidity, dumbbells of length 75 mm, the length and width of the narrow part of these being respectively 30 mm and 4 mm, were punched out of the membrane, and these were tested for tensile strength (breaking force), elongation at break and modulus of elasticity (at from 0.5 to 5% elongation) in accordance with DIN EN 53504 at a tensile testing rate of 200 mm/min. Test samples for determination of tear strength were also punched out of the material, and tested in accordance with DIN ISO 34 at a tensile testing rate of 500 mm/min. Appearance and formation of bubbles were assessed visually on the membranes produced.
[0183] Tables 1 to 6 state the results.
[0184] The liquid membranes F 1 to F 26 are inventive examples. The liquid membranes Ref 1 to Ref 12 are comparative examples.
[0000]
TABLE 1
Composition (in parts by weight) and properties of F 1 to F 5 and Ref 1 and Ref 2.
Liquid membrane
Ref 1
F 1
F 2
F 3
Ref 2
F 4
F 5
Component 1:
Lupranol ® 4003/1
—
10.00
20.00
30.00
—
10.00
20.00
Voranol ® CP 4755
46.79
41.29
35.79
30.29
44.54
39.04
33.54
1,4-Butanediol
2.75
2.75
2.75
2.75
2.50
2.50
2.50
Aldimine 1
6.00
6.00
6.00
6.00
8.50
8.50
8.50
Powdered quartz
44.00
39.50
35.00
30.50
44.00
39.50
35.00
K-Kat ® A-209 1
0.13
0.13
0.13
0.13
0.13
0.13
0.13
Salicylic acid 1
0.33
0.33
0.33
0.33
0.33
0.33
0.33
Component 2:
Isonate ® M 143
16.00
16.00
16.00
16.00
16.00
16.00
16.00
Polymer content 2
0
8.8
16.1
22.4
0
9.2
16.8
Viscosity (25° C.) 3
2.26
2.28
2.48
2.75
2.48
2.40
2.65
Pot life [min]
75
75
75
70
70
80
75
Flow-table value [cm]
20.4
20.1
20.7
21.0
20.0
20.0
21.1
Tensile strength
3.9
4.6
4.8
5.0
3.8
4.7
5.2
[MPa]
Elongation at break
250
250
230
210
230
275
220
[%]
Modulus of elasticity
8.6
9.3
8.0
7.2
8.5
9.7
9.1
[MPa]
Tear strength [N/mm]
14.1
13.9
13.7
13.3
14.5
14.6
14.5
Appearance,
tack-
tack-
tack-
tack-
tack-
tack-
tack-
bubble formation
free,
free,
free,
free,
free,
free,
free,
very
very
none
none
very
very
very
little
little
little
little
little
1 5% in dioctyl adipate
2 solid polymer from polymer polyol, based on entirety of polymer polyol and other polyol [% by weight]
3 of component 1 [Pa · s]
[0000]
TABLE 2
Composition (in parts by weight) and properties
of F 6 and F 7 and Ref 3 to Ref 7.
Liquid membrane
Ref 3
F 6
F 7
Ref 4
Ref 5
Ref 6
Ref 7
Component 1:
Lupranol ® 4003/1
—
10.00
20.00
—
10.00
20.00
30.00
Voranol ® CP 4755
42.29
36.79
31.29
52.52
47.02
41.52
36.02
1,4-Butanediol
2.25
2.25
2.25
3.35
3.35
3.35
3.35
Aldimine 1
11.00
11.00
11.00
—
—
—
—
Powdered quartz
44.00
39.50
35.00
44.00
39.50
35.00
30.50
K-Kat ® A-209 1
0.13
0.13
0.13
0.13
0.13
0.13
0.13
Salicylic acid 1
0.33
0.33
0.33
—
—
—
—
Component 2:
Isonate ® M 143
16.00
16.00
16.00
16.00
16.00
16.00
16.00
Polymer content 2
0
9.6
17.5
0
7.9
14.6
20.4
Viscosity (25° C.) 3
2.24
2.87
3.18
2.58
2.83
3.11
3.44
Pot life [min]
75
70
60
80
80
85
90
Flow-table value [cm]
20.1
21.0
20.6
19.6
19.8
21.7
20.5
Tensile strength
4.8
5.1
5.7
0.9
0.9
0.9
1.1
[MPa]
Elongation at break
225
215
200
80
75
115
130
[%]
Modulus of elasticity
10.2
9.9
10.6
8.3
6.8
5.8
5.9
[MPa]
Tear strength. [N/mm]
16.0
15.8
15.8
6.2
6.0
6.6
5.7
Appearance
tack-
tack-
tack-
tack-
tack-
tack-
tack-
bubble formation
free,
free,
free,
free,
free,
free,
free,
very
very
none
very
very
none
none
little
little
little
little
1 5% in dioctyl adipate
2 solid polymer from polymer polyol, based on entirety of polymer polyol and other polyol [% by weight]
3 of component 1 [Pa · s]
[0000]
TABLE 3
Composition (in parts by weight) and properties of F 8 to F 13 and Ref 8 and Ref 9.
Liquid membrane
Ref 8
F 8
F 9
F 10
F 11
Ref 9
F 12
F 13
Component 1:
Lupranol ® 4003/1
—
10.00
30.00
10.00
30.00
—
10.00
10.00
Voranol ® CP 4755
46.85
41.35
30.35
34.12
23.12
46.82
41.32
21.29
Castor oil
—
—
—
—
—
—
—
20.00
1,4-Butanediol
2.72
2.72
2.72
1.92
1.92
2.72
2.72
2.75
Aldimine 1
4.20
4.20
4.20
11.0
11.0
4.20
4.20
6.0
Aldimine 2
1.80
1.80
1.80
—
—
1.80
1.80
—
Powdered quartz
44.00
39.50
30.50
36.50
27.50
44.00
39.50
39.50
Zeolite paste
—
—
—
6.00
6.00
—
—
—
K-Kat ® A-209 1
—
—
—
0.13
0.13
0.13
0.13
0.13
DBTDL
0.10
0.10
0.10
—
—
—
—
—
Salicylic acid 1
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
Component 2:
Isonate ® M 143
16.00
16.00
16.00
16.00
16.00
—
—
—
Desmodur ® VH 20 N
—
—
—
—
—
19.0
19.0
28.0
Polymer content 2
0
8.8
22.4
10.2
25.4
0
8.8
8.8
Viscosity (25° C.) 3
2.24
2.05
2.64
2.38
2.89
n.d.
n.d.
1.95
Pot life [min]
20
20
20
>150
>150
70
65
45
Flow-table value [cm]
19.5
19.6
19.9
21.0
21.2
19.6
19.6
20.0
Tensile strength [MPa]
7.5
8.2
9.3
7.6
8.8
5.9
7.3
11.8
Elongation at break [%]
210
195
200
275
240
220
245
145
Modulus of elasticity
14.1
13.7
13.7
11.8
11.8
11.3
12.8
18.2
[MPa]
Tear strength [N/mm]
13.2
13.1
13.1
12.3
12.7
13.3
14.4
14.3
Appearance,
tack-
tack-
tack-
tack-
tack-
tack-
tack-
tack-
bubble formation
free,
free,
free,
free,
free,
free,
free,
free,
little
little
little
none
none
very little
very little
very little
“n.d.” means “not determined”
1 5% in dioctyl adipate
2 solid polymer from polymer polyol, based on entirety of polymer polyol and other polyol [% by weight]
3 of component 1 [Pa · s]
[0000]
TABLE 4
Composition (in parts by weight) and properties of F 14 to F 19 and Ref 10 and Ref 11.
Liquid membrane
Ref 10
F 14
F 15
F 16
Ref 11
F 17
F 18
F 19
Component 1:
Lupranol ® 4003/1
—
10.00
20.00
30.00
—
10.00
20.00
30.00
Voranol ® CP 4755
49.01
43.53
38.03
32.53
46.79
41.29
35.79
30.29
1,4-Butanediol
3.01
3.01
3.01
3.01
2.75
2.75
2.75
2.75
Aldimine 1
3.50
3.50
3.50
3.50
6.00
6.00
6.00
6.00
Powdered quartz
44.00
39.50
35.00
30.50
44.00
39.50
35.00
30.50
K-Kat ® A-209 1
0.13
0.13
0.13
0.13
0.13
0.13
0.13
0.13
Salicylic acid 1
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
Component 2:
Desmodur ® VH 20 N
19.0
19.0
19.0
19.0
19.0
19.0
19.0
19.0
Polymer content 2
0
8.4
15.5
21.6
0
8.8
16.1
22.4
Pot life [min]
>95
80
85
85
75
75
80
80
Flow-table value [cm]
19.5
19.4
20.3
20.4
19.7
19.9
20.3
20.3
Tensile strength
5.0
6.0
6.6
7.0
5.9
6.7
7.4
8.1
[MPa]
Elongation at break
260
255
250
225
260
270
240
230
[%]
Modulus of elasticity
13.9
13.0
11.9
12.7
12.9
12.9
13.5
13.2
[MPa]
Tear strength [N/mm]
15.2
14.9
14.0
14.0
14.8
14.7
14.7
14.2
Appearance,
tack-
tack-
tack-
tack-
tack-
tack-
tack-
tack-
bubble formation
free,
free,
free,
free,
free,
free,
free,
free,
very little
very little
very little
very little
very little
very little
very little
very little
1 5% in dioctyl adipate
2 solid polymer from polymer polyol, based on entirety of polymer polyol and other polyol [% by weight]
[0000]
TABLE 5
Composition (in parts by weight) and properties of F 20 to F 26 and Ref 12.
Liquid membrane
Ref 12
F 20
F 21
F 22
F 23
F 24
F 25
F 26
Component 1:
Lupranol ® 4003/1
—
10.00
30.00
—
—
—
—
—
Desmophen ® 5028 GT
—
—
—
22.50
45.00
22.50
45.00
22.50
Voranol ® CP 4755
42.26
36.85
25.85
28.79
10.79
26.54
8.54
24.29
1,4-Butanediol
2.28
2.28
2.28
2.75
2.75
2.50
2.50
2.25
Aldimine 1
11.0
11.0
11.0
6.00
6.00
8.50
8.50
11.00
Powdered quartz
44.00
39.50
30.50
39.50
35.0
39.50
35.0
39.50
K-Kat ® A-209 1
0.13
0.13
0.13
0.13
0.13
0.13
0.13
0.13
Salicylic acid 1
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
Component 2:
Desmodur ® VH 20 N
19.0
19.0
19.0
—
—
—
—
—
Isonate ® M 143
—
—
—
16.00
16.00
16.00
16.00
16.00
Polymer content 2
0
9.6
24.2
8.8
16.1
9.2
16.8
9.6
Viscosity (25° C.) 3
n.d.
n.d.
n.d.
3.34
5.17
2.93
4.67
3.17
Pot life [min]
80
90
80
70
60
65
60
70
Flow-table value [cm]
20.2
20.1
20.2
20.2
19.8
20.8
20.6
20.6
Tensile strength
6.6
7.5
9.7
4.2
5.2
5.2
6.1
6.7
[MPa]
Elongation at break
250
245
245
215
195
225
205
215
[%]
Modulus of elasticity
11.4
12.9
10.0
11.5
13.5
12.1
14.8
15.6
[MPa]
Tear strength [N/mm]
15.2
15.4
15.4
13.8
13.8
14.2
14.3
15.1
Appearance,
tack-
tack-
tack-
tack-
tack-
tack-
tack-
tack-
bubble formation
free,
free,
free,
free,
free,
free,
free,
free,
very little
very little
very little
little
little
little
little
very little
“n.d” means “not determined”
1 5% in dioctyl adipate
2 solid polymer from polymer polyol, based on entirety of polymer polyol and other polyol [% by weight]
3 of component 1 [Pa · s]
[0185] It will therefore be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
|
The present disclosure relates to a two-component composition containing a polymer polyol, a dial chain extender, an aldimine of formula (I), optionally additional polyols and diphenylmethandiisocyanates in the two components. The composition is particularly suitable as a manually applicable solvent-free liquid film for coating and/or sealing floors and roofs. It also has a long open time, cures quickly and without complications in a wide temperature and humidity range, has a high level of strength and is weather resistant.
| 2
|
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for starting an internal combustion engine and, more particularly, to an improvement in a rope starting apparatus for starting a small-sized internal combustion engine.
Generally, small-sized internal combustion engines are provided with manually operable starting apparatus such as recoil starter using a rope. This rope starting device has a reel around which is wound a rope. As the rope is pulled, the reel is rotated to impact a starting inertia to the engine crank shaft through a clutch, thereby to start the engine. In this starting operation by pulling the rope with hand for rotating the crank shaft, a large load is imposed during the compression stroke of the engine to hinder the rotation of the engine crank shaft.
In order to facilitate the rotation of the crank shaft during the starting, the exhaust valve of the engine is temporarily kept opened to keep the engine in the state of decompression and, when a sufficient inertia is obtained, the exhaust valve is released to take operative position to dismiss the state of decompression thereby to start the engine. This device for temporarily keeping the exhaust valve in the opened position is usually referred to as "decompression device".
In starting an engine provided with both of rope starting device and decompression device, it is necessary to manipulate both devices simultaneously. This inevitably requires two operators for the starting operation.
Another problem concerning the rope starting device is that a strong impact is imparted to the arm of the operator pulling the rope when the crank shaft of the engine rotates beyond the top dead center in the compression stroke. An extremely large impact is given to the operator's arm dangerously particularly when the engine has a large compression ratio.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide a starting apparatus for internal combustion engine equipped with both of a recoil starting device and a decompression device, capable of being manipulated by only one operator.
It is another object of the invention to provide a starting apparatus of a safe starting apparatus for an internal combustion engine, which is designed and constructed to eliminate the impact given to the operator's arm during the pulling of the rope.
It is still another object of the invention to provide a starting apparatus for an internal combustion engine in which a knob attached to the rope of the rope starting device is improved to obviate the impact which is given to the operator's arm during the starting operation.
To these ends, according to the invention, there is provided an apparatus for starting an internal combustion engine comprising: a rope starting device including a rope provided with a knob, a reel around which the rope is wound and a clutch adapted to transmit the rotation of the reel to an engine cranks shaft; and a decompression device including a cam adapted to forcibly open an exhaust valve by pushing one end of a valve lever and a shaft on which the cam is fixed to be biased resiliently and rotatively in one direction, the amount of push of the end of the valve lever being set to be smaller than that provided by a push rod of the valve actuating mechanism.
The above and other objects, as well as advantageous features of the invention will become clear from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly sectioned side elevational view of a small-sized internal combustion engine provided with a starting apparatus embodying the present invention;
FIG. 2 is a sectional plan view taken along the line II--II of FIG. 1;
FIG. 3 is a vertical sectional view of the engine shown in FIG. 1 with its exhaust valve held in a decompression position;
FIG. 4 is a vertical sectional view of the engine shown in FIG. 1 with the exhaust valve held in an exhausting position;
FIG. 5 is a vertical sectional view of an example of a recoil starter incorporated in the apparatus of the invention;
FIG. 6A is a sectional view taken along the line VI--VI of FIG. 5 and showing the knob in non-operating state;
FIG. 6B is a sectional view similar to FIG. 6A but shows the knob in the pulled state;
FIGS. 7A and 7B are vertical sectional views of the knob in the non-operating state and operating state, respectively;
FIGS. 8A and 8B are vertical sectional views of another example of the knob in the non-operating state and operating state, respectively;
FIG. 9A is a vertical sectional view of still another example of the knob;
FIG. 9B is a sectional plan view taken along the line IX--IX of FIG. 9A;
FIG. 10A is a front elevational view of a further example of the knob;
FIG. 10B is a sectional view taken along the line X--X of FIG. 10A;
FIG. 11 is a sectional view of a still further example of the knob;
FIGS. 12A and 12B are vertical sectional views of a still further example of the knob in the non-operating and operating states, respectively;
FIG. 13 is a vertical sectional view of still further example of the knob; and
FIGS. 14A and 14B are longitudinal sectional views of a still further example of the knob in the non-operating and operating states, respectively.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a reference numeral 1 denotes a cylinder accomodating a piston 2 adapted to make a reciprocating movement therein. A cylinder head attached to the top of the cylinder 1 is designated at a reference numeral 3. An exhaust valve 4 is mounted on the cylinder head 3. The exhaust valve 4 is resiliently biased by a spring 5 in such a direction that the valve head 4a thereof is kept in contact with a cooperating valve seat. A reference numeral 6 denotes a valve lever supported rockably around the axis of a fulcrum shaft 7 and having one end held in contact with the upper end of the stem of the exhaust valve 4. A seat 9 having an adjusting screw is fixed by a lock nut 10 to the other end of the valve lever 6. A push rod 11 makes a contact at its upper end with the seat 9.
The push rod 11 is adapted to push the other end of the valve lever 6 through the seat 9 during the exhaust stroke of the engine. Since the valve lever 6 is rockably supported by the fulcrum shaft 7, the other end of the valve lever 6 depresses the top end of the stem of the exhaust valve 4 to forcibly open the exhaust valve 4 overcoming the force of the spring 5.
The other end of the valve lever 6 having the seat 9 is provided with another seat 12 attached thereto by means of a lock nut 13 at a position in the vicinity of the first-mentioned seat 9. The seat 12 also is provided with an adjusting screw making a screwing engagement with the lock nut 13, so that the amount of downward projection of the seat 12 is adjustable through rotation of the lock nut 13. A cam 15 fixed to a shaft 14 is disposed under the seat 12. The shaft 14 is rotatably mounted on the cylinder head 3 and is rotatively biased in the clockwise direction as shown in FIG. 1 by a spring 16 which has a spring force smaller than that of the valve spring 5 of the exhaust valve 4. The cam 15 can be operated externally by means of an operation lever 17 attached to the other end of the shaft 14.
Therefore, as the operation lever 17 is rotated counter-clockwise from the position shown in FIG. 1 to the position shown in FIG. 3, the flat surface of the cam 15 pushes the seat 12 upward so that the exhaust valve 4 is slightly opened through the valve lever 6. The chamber in the cylinder 1 is kept in the state of decompression by this slight opening of the exhaust valve 4. The degree of decompression can be varied by changing the amount of downward projection of the seat 12 through an adjustment of the lock nut 13.
Anyway, it is essential in the present invention that the amount of push-up of the valve lever 6 by the cam 15 is smaller than that effected by the push rod 11.
The mutual engagement of the cam 15 and the valve lever 6 can be automatically dismissed when the cam 15 is separated from the seat 12 and rotated clockwise by the resilient biasing force of the spring 16, as the push rod 11 pushes the valve lever 6 in the exhaust stroke. Therefore, the exhaust valve 4 is kept closed when the push rod 11 is lowered for the next compression stroke so that the decompression does not take place. A reference numeral 18 denotes a cylinder head cover.
A reference numeral 19 generally denotes a recoil starter which is a typical example of a rope starting device. The recoil starter 19 has a reel 20, a rope 21 wound around the reel 20 and a knob 22 connected to the end of the rope 21.
The construction of the recoil starter will be described in more detail with specific reference to FIG. 5, as well as FIGS. 6A and 6B.
A shaft 23 is attached to the inside of a cover case 25 fixed to the engine body. The aforementioned reel 20 is rotatably carried by this shaft 23. A coiled spring 24 coiled around the shaft 23 has one end fixed to the shaft 23, whereas the other end of the coiled spring 24 is connected to the reel 20. The aforementioned rope 21 having the aforementioned knob 22 to its one end is connected at its other end to this reel 20. The arrangement is such that the reel 20 rotates around the shaft 23 as the rope 21 is pulled by means of the knob 22 but is reversed by the resetting force of the coiled spring 24 to take up and wind the rope 21 again as the latter is released.
Two projections 20a and 20b are formed on one side of the reel 20 at both sides of the center of rotation. A claw 26 is rotatably supported by the projection 20a, as a center shaft. The claw 26 has two arcuate slots 26a and 26b which are adapted to receive the shaft 23 and the projection 20b, respectively. Therefore, the claw 26 can oscillate around the projection 20a while bieng guided by the projection 20b. The claw 26 is provided at a portion of outer periphery thereof with a hooked portion 26c, and is slightly pressed by means of a nut 25 and a plate 27 at the end of the shaft 23. The pressing force is adjustable by means of a spring 31.
On the other hand, a pulley 30 is secured to a fly wheel 28 fixed to the engine crank shaft 29. The other end of this pulley 30 is extended to cover the outer periphery of the claw 26. A plurality of recesses 30a are formed in the inner peripheral surface of the pulley 30 at a portion of the latter corresponding to the claw 26.
In the above-described recoil starter, as the rope 21 is pulled out of the reel 20 by means of the knob 22, the claw 26 is swung outwardly around the projection 20a due to the centrifugal force from the state shown in FIG. 6A to the state shown in FIG. 6B, so that the hooked portion 26c of the claw 26 comes into engagement with the recess 30a of the pulley 30. As a result of this engagement, the pulley 30 is rotated to impart a torque to the crank shaft 29 through the fly wheel 28 thereby to start the engine. Then, as the engine is started, the hooked portion 26c of the claw 26 is pressed back toward the inside as shown by chain line in FIG. 6B by the inner peripheral surface of the pulley 30, because the latter rotates at a high speed after the start of the engine, so that the engagement between the hooked portion 26c and the recess 30a is dismissed. Then, as the knob 22 is released from the operator's hand, the reel 20 is reversed by the resetting torque of the coiled spring 24 to wind the rope 21 therearound.
The engine having the described decompression device and rope starting device in combination is started in a manner described hereinunder.
As the knob 22 of the recoil starter, i.e. the rope starting device, is pulled gently, the clutch is out into engagement to rotate the crank shaft 29. As the compression stroke is commenced, the resistance imparted to the rope is increased. The pulling of the rope 21 is suspended temporarily in this state.
Subsequently, the operation lever 17 of the decompression device is rotated counter-clockwise as shown in FIG. 2. In consequence, the cam 15 pushes the seat 12 upward to slightly open the exhaust valve 4 thereby to establish the state of decompression. The rope 21 is then set to the first position wound round the reel 20 and is then pulled strongly by means of the knob 22. The engine crank shaft 29 is rotated by this action. The first compression stroke is passed without substantial resistance, because the engine is kept in the state of decompression. Subsequently, the push rod 11 pushes the seat 9 of the valve lever 9 upward to bring the cam 15 out of engagement with the seat 12. Since the shaft 14 is rotatively biased in the clockwise direction as viewed in FIG. 1 by the spring 16, the cam 15 is automatically rotated as it is released from the seat 12 so that the state of decompression can no more be realized unless the operation lever 17 is operated. Namely, the decompression state of the engine is automatically dismissed.
Since the rope 21 is being pulled continuously in this state, the crank shaft is rotated further to start the second compression stroke. In this state, a sufficient inertia has been accumulated to rotate the crank shaft at a considerably high speed, so that the piston passes the top dead center for the second compression stroke which is, in this state, conducted without decompression, thereby to start the engine.
Thus, according to the invention, the previously achieved state of decompression is automatically dismissed during the pulling of the rope, in the exhaust stroke of the engine. It is therefore not necessary to make an additional manual operation for resetting the engine from the state of decompression to the state of normal operation in which the compression is made in due course. The setting of the decompression state made by the operation lever 17 is made when the pulling of the rope 21 is temporarily stopped, as stated before. It is therefore possible to operate the decompression device and the rope starting device by only one operator.
It will be clear to those skilled in the art that, in rotating the reel 20 by pulling the rope 21 of the recoil starter, a considerable reaction is imparted to the rope 21 when the piston moves beyond the top dead center for the second compression stroke, so that a shock is imparted to the arm of the operator.
This shock, however, can be diminished by adopting a special connecting construction between the knob 22 and the rope 21. FIGS. 7 to 14 show different examples of the connecting construction between the knob 22 and the rope 21 for diminishing the shock.
Referring to FIGS. 7A and 7B, a T-shaped body of the knob 22 is provided at its central part with a cylindrical bore 40 having a bottom receiving a cylindrical buffer 41 made of rubber and having a diameter slightly smaller than the diameter of the bore 40. The buffer 41 is provided with a concentric through bore 41' receiving the end of the rope 21. A knot 43 is formed out of a washer 42. Thus, the knob 22 is connected to the rope 21 through a medium of the buffer 41. A reference numeral 44 denotes a stopper. FIG. 7A shows the state before the pulling of the rope 21. As the rope 21 is pulled from this state, the cylindrical buffer 41 is compressed in the longitudinal direction thereof thereby to absorb and diminish the impact transmitted to the rope 21.
FIGS. 8A and 8B show a modification of the knob shown in FIGS. 7A and 7B. In this modification, the inside diameter of the bore 40 formed at the center of the knob 22 is selected to be sufficiently large as compared with the outside diameter of the cylindrical buffer 41 made of rubber. At the same time, the inner surface of the bore 40 is recessed as at 40a to expand radially outwardly at a portion thereof corresponding to the buffer 41.
Further, the lower end corner of the cylindrical buffer member 41 is shaped to have an arcuate or curved surface R. Therefore, as the rope 21 is pulled from the position shown in FIG. 8A, the cylindrical buffer 41 is deflected at its central portion as shown in FIG. 8B and deformed to expand radially outwardly. The curved surface R at the lower end of the cylindrical buffer 41 is provided for facilitating this buckling.
FIGS. 9A and 9B show another example of the knob 22 in which the bore 40 of the knob 22 is made to have a groove-like form. A tabular buffer 45 made of rubber is retained in this groove-like bore 40 by means of projection 46. In order to preserve a sufficiently large space between the groove-like bore 40 and the tabular buffer 45, the bottom of the groove-like bore 40 is shaped to have a recess 40a. As the rope 21 is pulled by this knob 22, the tabular buffer 45 is deflected at its central part while both ends thereof being retained by the projections 46, thereby to absorb and diminish the impact.
FIGS. 10A and 10B show still another example in which the body of the knob 22 is composed of two plates 22a and 22b between which clamped is a tabular buffer 46 made of rubber. The tabular buffer 46 is fixed by means of pins 47. The rope 21 is connected to the lower end of this tabular buffer 46. Therefore, as the rope 21 is pulled by means of the knob 22, the tabular buffer 46 is extended to absorb and diminish the impact.
FIG. 11 show a further example in which a leaf spring 48 constituting the buffer is cantilevered in the bore 40 formed in the body of knob 22. The rope 21 is connected and secured to the free end of this buffer 48 by means of a knot 43.
Referring now to FIGS. 12A and 12B showing a still further example of the knob, the bore 40 formed in the knob 22 is tapered such that the width thereof is gradually decreased toward the lower side. At the same time, a ring-shaped recess 40a is provided on the upper end of the bore 40. A deflected buffer 49 consisting of a bent leaf spring is received by the bore 40 such that it resiliently presses the inner surface of the bore 40. The rope 21 is connected to the central portion of this deflected buffer 49 by means of a knob 43. FIG. 12A shows the state before pulling the rope 21, in which the deflected buffer 49 is retained at its both ends by the recess 40a and the bore 40. As will be seen from FIG. 12B, the both ends of the deflected buffer 49 leave the recess 40a as the rope 21 is pulled and slide along the tapered wall of the bore thereby to absorb and diminish the impact. The deflected buffer 49 automatically climbs the tapered wall of the bore 40 to fit the recess 40a again, thanks to its resiliency.
FIG. 13 shows a still further example of the knob in which the rubber buffer 41 of the example shown in FIGS. 7A and 7B is substituted by a buffer 50 made of a coiled spring.
A still further example of the knob shown in FIGS. 14A and 14B is a modification of that shown in FIG. 13. In this example, a pair of balls 52 are received by retaining portion 51 provided at the end of the rope 21. These balls 52 are resiliently pressed against the inner surface of the bore 40a by means of the spring 53. Before the pulling of the rope 21, the pair of balls 52 fit the recess 40a of the bore 40 as shown in FIG. 14A to retain the retaining portion 51. However, as the rope 21 is pulled, the balls 52 are moved out from the recess 40a so that the retaining portion 51 is lowered absorbing and diminishing the impact transmitted to the rope 21. The starting condition shown in FIG. 14A is resumed as the knob 22 is released.
As has been described, according to the invention, the internal combusition engine equipped with both of a decompression device and a rope starting device can be started by only one operator, because the decompression device which is set beforehand is automatically dismissed during operation of the rope starting device. Further, the operator is protected against the large impact which takes place when the crank shaft is rotated beyond the top dead center for a compression stroke, thanks to the impact absorbing and diminishing mechanism provided in the knob attached to the rope.
The present invention is not, of course, limited to the above-described embodiments but may be modified in various ways within the scope of the appended claims.
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An apparatus for starting an internal combustion engine which comprises: a rope starting device including a rope provided with a knob, a reel around which the rope is wound and a clutch adapted to transmit the rotation of the reel to an engine crank shaft; and a decompression device including a cam adapted to forcibly open an exhaust valve by pushing one end of a valve lever associated with the exhaust valve and a shaft on which said cam is fixed to be biased resiliently and rotatively in one direction, the pushing amount of the end of the valve lever by the cam being set to be smaller than the pushing amount of the same effected by a push rod of a valve actuating mechanism for the exhaust valve. When the end of the valve lever is pushed by the cam, the cam engages the valve lever while keeping the exhaust valve in the opened state, whereas when the push rod pushes the end of the valve lever, the cam is disengaged from the valve lever.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to modern control systems and, more particularly, to negative feedback loops in such systems.
2. Description of the Art
FIG. 1 illustrates a known control system utilizing a negative feedback loop in a low drop-out (LDO) amplifier application 100 . This particular application 100 is configured as an LDO regulator circuit. An LDO regulator is a circuit that provides a well-specified and stable DC voltage. The lowest value of differential (input/output) voltage at which the control loop stops regulating is called the dropout voltage. Modern applications such as communication electronics and other battery-powered portable devices require a low dropout voltage and low quiescent currents for increased power efficiency. LDO regulators meet both of these design needs.
At the input stage, a reference input signal V REF is fed into the inverting input of a dual stage amplifier 104 . The output from the amplifier controls a field effect transistor (FET) Q 1 that acts as a switch for supplying current from the power source V DD to the load (modeled as a resistor R L in the figure). Some of the current flowing between the source and the drain of Q 1 is then fed back through a simple RC filter network into the non-inverting input of the amplifier 104 . This feedback signal is called V FB . The RC filter network comprises capacitor C 1 and resistors R 1 and R 2 . C 1 AC-couples the output back into amplifier 104 . Resistors R 1 and R 2 are configured in a voltage divider with R 2 connected to ground. The ratio between the values of R 1 and R 2 may be adjusted to set the output voltage, V OUT , to a desired value.
V OUT is fed back through the RC filtering network yielding signal V FB at the non-inverting input of the amplifier. Typically, differential amplifiers are used in modern electronic circuits. Differential amplifiers amplify the voltage difference between two input signals. When the output of a differential amplifier is connected to its inverting input and a reference voltage signal is applied to the non-inverting input, the output voltage of the op-amp closely follows that reference voltage. As the amplifier output increases, that output voltage is fed back to the inverting input, thereby acting to decrease the voltage differential between the inputs. When the input differential is reduced, the amplifier output and the system gain are also reduced. In FIG. 1 , because amplifier 104 is a dual-stage amplifier, the reference signal is shown connected to the inverting input rather than the non-inverting input. Nevertheless, because the output is fed back in a manner that reduces the system gain, the result is negative feedback, sometimes called degenerative feedback.
Negative feedback is often employed to stabilize a control system when the system exhibits a gain from the input to the output. The output stage 120 in this LDO application is modeled by load resistor R L and an output capacitor C 0 which is needed to deliver an instantaneous current to a dynamic load. C 0 has a characteristic equivalent series resistance (ESR) modeled by a series resistor R ESR . ESR is an effective resistance that is used to describe the resistive part of the impedance of certain electrical components such as capacitors.
An important characteristic of this type of control circuit is the ratio between the output and input signal amplitudes, known as the transfer function. The transfer function for any given system is used to model the gain of the system as a function of the input signal frequency. Such control systems are often designed to meet the specifications of a transfer function. The frequency response of the control system is completely described by its transfer function. As such, the stability of a system over a range of input signal frequencies may be predicted based upon properties of its transfer function known as poles and zeros. A pole is a root of the polynomial denominator of a transfer function; a zero is a root of the polynomial numerator.
In designing stable systems, one important consideration is the shift in phase that a signal undergoes as it passes through the system. Poles and zeros are associated with these shifts in phase. If the signal accumulates a shift in phase of 180 degrees, the shift causes the negative feedback to become positive feedback. This is problematic when the system is operating at greater than unity gain as positive feedback will drive the system to an unstable oscillatory state. In order to maintain the stability of the control system, designers often build in a phase shift buffer, called a phase margin. For example, a 50 degree phase margin ensures that the signal never undergoes a phase shift of more than about 130 degrees (i.e. it never comes within approximately 50 degrees of a 180 degree phase shift). 50 degrees is a typical value of a phase margin in an LDO design; however, a 50 degree phase margin is not a requirement for stability and smaller phase margins of 45 degrees or lower may suffice. Furthermore, although a design goal may be to maintain a particular phase margin, the actual performance of a system may be less than the nominal phase margin value. The nominal value of the phase margin is chosen to meet the specifications of a particular design and may vary significantly.
Both poles and zeros can be introduced into the transfer function describing the control loop by inserting various electronic components into the loop. For example, a dual-stage amplifier will create two poles in the transfer function. The addition of poles and zeros into the frequency response of a system must be taken into account in order to design a system with a bounded (finite) output. Unwanted or unavoidable poles and zeros can create significant challenges when trying to stabilize a control system over a range of operating frequencies.
Previously, efforts have been made to stabilize a control system by designing the system so that troublesome poles only affect the system negligibly over the operating frequency range. This approach limits the designer to specific component values and configurations. For example, an output stage may include a capacitor having an ESR which adds a zero to the transfer function at a certain frequency. In order to realize a stable system, the capacitor must be limited to values such that the added zero does not interfere with the system response over the input frequency range. For this reason, small variations in the value of the ESR in an output capacitor can have a significant destabilizing effect on the entire system. A major goal of electronic system design is to avoid limiting circuit components to a precise value or range of values, allowing for easy replacement and substitution of components.
Another previous effort to stabilize control systems involves raising the quiescent current. The quiescent current, sometimes called the leakage current, is the portion of the input current that does not contribute to the load current. In other words, it is the current that the system consumes when no load current is being supplied. By raising the quiescent current, non-dominant poles in the system can be pushed to much higher frequency levels outside the system's normal operating range. A drawback of this stabilization method is that a higher quiescent current drains the batteries that power the system. For this reason many modern applications demand a low quiescent current for increased battery lifetime.
SUMMARY OF THE INVENTION
The present invention seeks to provide a novel control circuit and associated method for improving the stability of feedback loops in control circuits. The invention allows control system electronics to be designed with greater flexibility in component choice and improved stability over a broader range of input frequencies.
These goals are achieved, according to one embodiment of the invention, by providing a control circuit with a negative feedback control loop that includes at least one input stage and at least one output stage, the output stage having an associated ESR. The control circuit further includes a sub-circuit that emulates a second ESR. The second ESR is a scaled version of the ESR of the output stage and is AC-coupled into the control loop at a desired frequency.
An associated method for improving the stability of feedback loops couples an amplified signal back into an amplifying device to produce a negative feedback control loop having a characteristic transfer function. An ESR is emulated within the control loop to introduce a zero into the transfer function at a desired frequency.
These and further features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a prior art low dropout (LDO) regulator circuit.
FIGS. 2 , 3 , 4 and 5 are schematic diagrams of an LDO regulator circuit featuring different respective embodiments of the present invention.
FIG. 6 is a flow diagram of a method for stabilizing a negative feedback control loop in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 illustrates one embodiment of a novel control circuit. The control circuit exhibits improved stability over the prior art for a broad range of input frequencies by emulating an ESR within the circuit and adding a zero to the transfer function at a desired frequency. The design is more immune to variations in the actual ESR of the output capacitor and other board parasitic elements such as trace inductance in series with the output capacitor. The control circuit is designed to drive a wide variety of load circuits. Some examples of such load circuits are a processor, an amplifier, a digital to analog converter or a pulse width modulation switching regulator.
The control circuit shown in FIG. 2 is an LDO regulator application with an additional emulated ESR that is AC-coupled into the system control loop to stabilize the system. The sub-circuit 200 is an example of one circuit that may be used to emulate the additional ESR.
In this embodiment sub-circuit 200 comprises a feedback FET Q 2 and an RC network consisting of coupling capacitor C 2 and resistor R 4 . C 2 connects the drain of Q 2 to the non-inverting input of amplifier 104 , and R 4 connects the drain of Q 2 to ground. The base of Q 1 is connected to the base of Q 2 , allowing Q 2 to function as a current mirror that outputs a scaled version of the current flowing through Q 1 . The scaling factor is adjusted by varying the width of Q 2 . If the width of Q 2 is increased, more current flows through sub-circuit 200 increasing the gain around the loop and the emulated ESR. Because the size of Q 1 is determined by the maximum current that it is required to supply, the width of Q 1 always remains the same for a given load (modeled here as R L ).
The current flowing through Q 2 is supplied to the RC network through node 208 . The components of the RC network are chosen to emulate C 0 with an ESR that is scaled in proportion to the ESR of C 0 . The voltage produced at node 208 is AC-coupled through C 2 and contributes to signal V FB . An additional resistor R 3 is needed between the junction of resistors R 1 /R 2 and the non-inverting input amplifier 104 when the control circuit is designed to operate at unity gain (i.e. when the value of R 1 is zero ohms).
The ESR of sub-circuit 200 adds a zero to the characteristic transfer function of the loop. A pole that accompanies this zero is at a much higher frequency and has negligible effect on the stability of the control loop. The designer can easily adjust the value of the emulated ESR, and hence the frequency position of the added zero, by changing the size of the components that compose sub-circuit 200 .
Equation 1 shows the relationship between the frequency of the added zero (f zero ) and the values of several components in the circuit where R 4 is the value of the emulated ESR and N is the ratio of the widths of Q 2 over Q 1 :
f
zero
=
1
2
π
·
N
·
R
4
·
C
O
·
C
1
C
2
Equation
1
As a result of the emulated ESR, the control circuit is stable over a desired range of input frequencies. Signal V OUT is thus able to drive load R L within the desired range.
Another embodiment of the new control circuit is illustrated in FIG. 3 , in which an LDO regulator device is similar to the one illustrated in FIG. 2 . Sub-circuit 300 includes the same components and has the same structure as sub-circuit 200 except that sub-circuit 300 comprises an additional resistor R 5 connecting V DD and the source of Q 2 .
Adding an additional resistance R 5 between V DD and Q 2 reduces the gain around the loop (through node 310 back to the input of amplifier 104 ) when the system is operating at higher load levels. As load levels increase, higher order poles and zeros that were not significant at lower load levels begin to impact the system response. For this reason the designer may wish to push the zero added by the emulated ESR to higher frequencies to compensate for these higher order poles and zeros. This can be accomplished by decreasing the gain around the loop including sub-circuit 300 . Equation 1 shows how changing various component values will affect the frequency of the added zero.
The current flowing through Q 2 is proportional to the current flowing through Q 1 . This proportion is adjusted by changing the width of Q 2 . If the width of Q 2 is increased, the gain around the loop through node 310 (defined by the junction of Q 2 , C 2 and R 4 ) is increased and the frequency of the added zero is reduced. The current flowing through Q 2 travels into the RC network, producing a voltage at node 310 . The voltage produced at node 310 is AC-coupled through C 2 to signal V FB . An additional ESR is emulated by sub-circuit 300 , inserting a zero into the transfer function at a desired frequency.
Another embodiment of the new control circuit is illustrated in the LDO regulator application of FIG. 4 . The regulator device is the same as the one illustrated in FIG. 2 except that sub-circuit 400 includes a tracking FET Q 3 in place of R 4 . Node 410 is defined by the junction of Q 2 and Q 3 . The drain and gate of Q 3 are both connected to ground. As explained above, the current flowing through the loop including sub-circuit 400 is proportional to the load current. In this configuration the resistance of Q 3 decreases proportional to the square root of the current flowing through it. Thus, Q 3 provides sub-circuit 400 with a variable resistance, and thus a variable ESR, that scales itself in proportion to the current through load R L .
The variable ESR of Q 3 provides for greater system stability when the control circuit is designed to drive a dynamic load (not shown). The output current needed to supply a dynamic load can change drastically and rapidly. As the load current changes, so do the positions of certain poles in the transfer function. This necessitates a dynamic zero to compensate for the effect of the dynamic pole. Tracking FET Q 3 is connected to produce a zero that tracks a dynamic pole resulting from a non-static load current.
FIG. 5 illustrates another embodiment of the invention, in an LDO regulator application similar to the regulator of FIG. 2 except for the sub-circuit used to emulate the additional ESR. Sub-circuit 500 comprises a feedback FET Q 2 and a tracking network consisting of FET Q 4 and amplifier 504 . The RC network consisting of capacitor C 2 and resistor R 4 is connected as shown in FIG. 2 . The sources of Q 1 and Q 2 are connected to power source V DD with the drains of Q 1 and Q 2 connected to the inputs of differential amplifier 504 . The output of amplifier 504 drives the gate of Q 4 which is connected between Q 2 and the RC network. Amplifier 504 is connected such that the drain voltages of Q 1 and Q 2 closely follow one another. Forcing these two drain voltages towards equality preserves the desired scaling factor. This is important because the ESR that is added to the circuit is proportional to the scaled current flowing into the RC network from Q 2 .
FIG. 6 illustrates the new method for improving stability in negative feedback control loops. First, an input signal is provided in step 600 . The input signal can be the output from another system or a reference voltage, for example. The input signal is then amplified to produce an output signal in step 602 . The gain associated with the amplification process is selected by the designer and achieved by biasing the control circuit with appropriate components. The output signal then passes through a network and a portion of the output signal is coupled back into the input signal to create a negative feedback control loop as shown in step 604 . In step 606 , as current passes through the negative feedback control loop, the control circuit emulates an ESR, adding a zero to the transfer function as shown in step 608 . The placement of the zero in the transfer function depends on the value of the ESR that is emulated by the circuit.
Some typical part values from the embodiments above are as follows:
R 1 =625 kΩ; R 2 =200 kΩ; R 3 =250 kΩ; R 4 =5 kΩ; C 0 =2.2 μF; C 1 =4.5 pF; C 2 =1 pF; Q 1 : width=30,000 μm; length=0.6 μm; Q 2 : width=8 μm; length=0.6 μm.
The values above may vary according to a particular application and are not meant to limit the invention in any manner.
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. For example, while described in connection with LDO linear regulators, the invention is applicable to many different applications utilizing control circuits, particularly those that include negative feedback loops. Although various component combinations have been described herein, other embodiments and component combinations will occur to those skilled in the art and may be used to realize the claimed invention. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
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AC-coupled equivalent series resistance (ESR) is introduced into a control circuit to provide additional stability in the feedback control loop. A sub-circuit emulates the effect of a higher value ESR in the output capacitor. The additional ESR in the feedback control loop inserts a zero into the transfer function that describes the circuit response at a desired frequency. The added zero compensates for the effects of unwanted or unavoidable poles in the transfer function, allowing for a greater range of input signal frequencies.
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This is a continuation of application Ser. No. 505,188 filed Sept. 11, 1974, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the assembling and disassembling of cutting tool inserts with multiple cutting edges into a cutting tool holder and the method for holding and locking the insert.
2. Description of Prior Art
The use of replaceable inserts in machine tool applications for cutting material in machining operations is well known and recognized in this art. Almost all of these devices are of the quick release and change type mechanisms for replacing the cutting tool insert and have anywhere from one to four pieces which make up the complete cutting tool. Many different devices for holding and securing the insert are known in this art wherein springs and pivots are used to assist in retraction of the locking device for quick change of the insert. Also in this art are may dual pin devices and pins which are expensive because of their shape and configuration. This invention overcomes these shortcomings by its simplicity and design.
SUMMARY OF THE INVENTION
This invention relates to an indexable insert securing means for replaceable tip cutting tools. Said inserts can be made from hard material such as carbide and this invention presents a novel means for securing and locking said insert into a pocket in the tool holder. The pocket sides coact with the insert when it is tightened into place by an angular tilting action of a pivotally recessed pin with a resilient member that locks the insert into the tool holder and provides a unique release of the insert.
A principal object of this invention is to provide a means for securely locking an indexable cutting tip in a tool holder pocket and includes a simple and quick mechanism for changing the tip.
Further object of this invention is to allow the use of utility inserts as well as precision ground inserts. The utility insert is recognized by industry as one with open tolerance on the cutting edges.
A further object is to allow the indexing of this tip as it becomes worn from use.
Another object is to provide an insert pocket in a tool holder which the the tilting lock pin will keep the cutting insert from rising up out of the seat when the insert is tightened into place and also during the stress of a cutting operation.
In this invention the axis of the locking screw positively determines the direction of applied force.
A further object of this invention is to provide proper vertical position of the screw which determines the amount of applied force.
Another object is to provide a resilient member which assists in releasing the insert from its pocket and this resilient member acts as a seal preventing cutting chips and dust from clogging the recessed pivot.
Another object of this invention is that the resilient member is slightly compressed so that it remains in position at all times.
Further object is to provide a resilient member which prevents the pin from falling out when the insert has to be changed while the tool holder is in a tilted or upside down position.
Still another object is to provide an inexpensive and low cost alternate to present methods of holding cutting tips.
Other objects of this invention will become apparent and will be best understood when taken in view of the accompanying drawing supplied herein.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of a cutting tool showing the relative location of the tool holder, cutting tip and locking pin.
FIG. 2 is a sectional view of the structure in FIG. 1 in a partially assembled position.
FIG. 3 is a sectional view of the structure in FIG. 1 along 3--3 in a locked position.
FIG. 4 is a front view of the cutting tool showing relative location of the cutting tip, locking pin, and screw.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, and partially to FIG. 1 through FIG. 3, therein is a cutting tool holder, referred to by numeral 5, consisting of a shank 10 generally rectangular in cross section with provisions for attaching to a tool post of a conventional metal cutting machine such as a lathe. The shank 10 is integrally connected to the head 12 which forms the whole of the tool holder 5 with the head 12 having a tapered trapeziform section which is smaller at the bottom 14 front than the shank 10 section. The top surface 15 is tipped down toward front surface 16 with a pocket consisting of bottom surface 18 as the seat and surfaces 20 and 22. The shape of the pocket consisting of surfaces 18, 20 and 22 is similar to insert 21 with the surfaces 20 and 22 having a 90° maximum angle to a slightly less than 90° angle to bottom surface 18 at undercut 24 shown in FIG. 2. A clearance hole 17 perpendicular to bottom surface 18 provides for clearance of the insert's 21 tip.
A cylindrical hole 27 in FIG. 2 with its axis perpendicular to the pocket surface 18 is accurately disposed in the head section 12 with chamfer 26 at the opening and with a recess hole 28 perpendicular to pocket surface 18 on the same center line as cylindrical hole 27 with a bottom surface 29 approximately parallel to pocket surface 18. Recess hole 28 is slightly larger than dowel pin 30.
The insert 21 has a hole 32 substantially at the goemetric center of the insert opposed faces, the axis of the hole 32 being substantially perpendicular to the parallel planes of said faces 23 and 31. Said insert 21 when in use, for example, can have a total of six cutting edges by indexing it three times and turning insert 21 upside down and indexing three more times. Other insert shapes, such as square and pentagonal, can afford still larger numbers of usable cutting edges and can be used with this invention.
A tilting lock pin or dowel pin 30, shown in FIG. 2, consists of a short end cylinder 38 which connects to an undercut cylinder 39 and to a long end cylinder 40. A resilient member 42, such as a standars size 0 ring made from rubber or similar material, is located at the undercut cylinder 39. This undercut 39 in pin 30 is located slightly below the pocket surface 18 so that resilient member 42 is approximately even with the surface 18. This affords the added advantage of keeping cutting chips and dust particles out of this hole. The resilient member 42 is sized so that it completely fills the void between the undercut 39 on pin 30 and hole 27. The set screw 44 is disposed in thread 45 in head 12 and is tightened with a standard allen type or hexagon key.
An optional clamp 47 is shown with a pivot surface 48 and clamp surface 49 which can lock the insert 21 into place by the differential screw 50. A recessed surface 52, shown in FIG. 1 and FIG. 3, allow pivot 48 room to rotate out of the way during insert position change or removal. Shoulder 53 acts as a stop for the pivot 48 on clamp 47 during the tightening process. Threads 55 disposed in head 12 will receive the differential screw 50 for clamping insert 21.
OPERATION OF THE INVENTION
The locking of insert 21 into tool holder 5 is shown in FIG. 2 and FIG. 3 and is as follows. The tilting lock pin 30 is inserted into recess 28 with resilient member 42 in place which also acts to center pin 30 in hole 27. The insert 21 is easily slipped over the short end cylinder 38 which is slightly smaller in diameter than the insert hole 32 with the chamfer 33 on the tilting lock pin 30 allowing for ease of insertion and removal of the insert 21.
With the insert 21 sitting on the surface 18 of the pocket, the set screw 44 in thread hole 45 can now be tightened and will make contact with the long end cylinder 40 of the tilting lock pin 30. As screw 44 is tightened, the short end cylinder 38 will make contact with the insert hole 32 exerting forces in such a way so as to bring faces 36 and 35, respectively of the insert 21 in contact with side surfaces 20 and 22 of the pocket. Movement of the tilting lock pin 30 will cause the resilient member 42 to be compressed, making its cross-section smaller but causing the section opposite to expand as shown exaggerated in FIG. 3. As pin 30 tilts in its recessed hole 28 to its final position, shown in FIG. 3, contact at 57 between long end cylinder 40 and hole 28 acts as a pivot point, causing the short end cylinder 38 to make contact 58 with insert hole 32 exerting locking forces between the insert rear surfaces 36 and 35 and the pocket back wall 20 and 22, respectively. Conversely, initial rotation in reverse of set screw 44 and interaction of resilient member 42 displaces the tilting lock pin 30 to skew away from contact with the insert hole 32 centralizing pin 30 by equalization of forces in the resilient member 42 allowing easy and rapid removal of the insert 21 for its indexing or replacement.
FIG. 3 is a sectional view illustrating the contact action between pocket back walls 22 and 20 and the insert 21. This is slightly exaggerated to show the clamping action of the intersection of top surface 15 and pocket back walls 20 and 22 which hold the insert 21 at or near the top. This clamping action is the result of the secure contact with the back walls 20 and 22 of the pocket which keeps the insert 21 firmly seated on pocket surface 18 when the tool holder 10 and insert 21 are in an actual machining operation. A further optional clamping is provided by clamp 47 which is shown clamping insert 21 in place by the action of pivot 48 on surface 52 and the tightening of differential screw 50.
Contact between a workpiece and the intersection of top surface insert 21 and front face 34 of the insert 21 will cause a force at this intersection which would cause faces 36 and 35 of the insert 21 to try to rise out of the pocket but is prevented from doing so because of the aforementioned clamping actions.
The clamping action of surfaces 20 and 22 interacting with surfaces 36 and 35 also prevents the insert 21 from rising up out of the pocket when it is tightened into place by the tilting lock pin 30 upon original installation on the insert 21 or when the insert 21 is indexed to expose a new cutting surface edge such as the intersection of top surface with faces 36 or 35 to a workpiece.
A slight spherical surface 60 is also provided in head 12, as shown in FIG. 1, which will allow a finger or thumb to slip down at the apex of the insert 21 to assist in removing it from the pocket.
Am essential feature of the invention is the contact locking facility that automatically adjusts by the further movement of the pin to form a clamping force, when tightened between the recessed hole and short cylinder of the pin that is transmitted through the pin to the surface of the hole in the insert (which by nature of the shape is forced into the pocket) by the pivot action of the pin causing the clamping result. It should also be noted that, because of this design, the system is self-adjusting and automatically compensates for any wear that occurs to the various contact surfaces. If the resilient member should wear because it becomes embrittled due to age, environment or use, it is a very inexpensive replacement item.
While preferred embodiments of the invention have been illustrated and described, it will be understood that various changes and modifications may be made without parting from the spirit of the invention.
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This invention is the method and apparatus for locking an indexable replaceable cutting tool insert into a cutting tool holder using a tilting pin type device consisting of a pivotally recessed pin with a resilient member and set screw which lock the insert into an insert pocket of the tool holder.
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FIELD
[0001] The present disclosure relates to heat exchangers. More particularly, the present invention relates to a heat exchanger which includes a side insert or side plate which is secured to the core plate mechanically without the use of brazing.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] Heat exchangers are used to exchange heat between two fluids. In the automotive industry, a heat exchanger in the form of a radiator is used to exchange heat between an engine cooling fluid and air. In addition, a heat exchanger is used to exchange heat between the engine coolant fluid and air to be blown into the passenger compartment to heat the air. Also, a heat exchanger in the form of a condenser is used to exchange heat between a refrigerant and air. Finally, a heat exchanger in the form of an evaporator is used to exchange heat between a refrigerant and air that is to be blown into the passenger compartment to cool the air.
[0004] Each of these heat exchangers includes a plurality of tubes through which a fluid flows, a plurality of fins arranged between adjacent tubes to be bonded to the tubes, a core plate connected to each longitudinal end of the plurality of tubes, a tank member disposed at each end of the plurality of tubes and an insert or side plate located at opposite sides of the plurality of tubes and fins. The inserts or side plates provide stability to the assembled heat exchanger.
[0005] Typically, the plurality of tubes and the inserts or side plates extend through apertures formed in each core plate and this assembly is brazed to maintain its integrity as well as to seal the interface between the tubes and the core plates and interface between the inserts or side plates and the core plates.
[0006] When both the insert or side plates and the plurality of tubes are brazed to the core plate, problems can occur due to thermal stress. In cold ambient temperatures and hot coolant conditions, the tubes want to expand due to their increased temperature due to the hot coolant. The inserts or side plates want to contract due to the cold ambient temperature. This creates relatively high stresses at the interfaces between the tubes and core plates and the interfaces between the inserts or side plates and the core plates. This high stress creates the potential for cracking and cooling leaks.
SUMMARY
[0007] The present disclosure describes a heat exchanger where the tubes and core plates are brazed together. The inserts or side plates are mechanically connected to the core plates rather than being brazed or in the alternative the inserts or side plates can be lightly brazed to the core plates. The interface region between the inserts or side plates and core plate is located outside of the sealed area of the radiator tank. This structure allows the tubes to expand when necessary without being constrained by the insert or side plate.
[0008] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0009] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0010] FIG. 1 is a schematic view of a vehicle cooling system and a vehicle air conditioning system;
[0011] FIG. 2 is a front view of the heat exchanger illustrated in the vehicle cooling system of FIG. 1 ;
[0012] FIG. 3 is an enlarged cross-sectional view of the upper portion of the heat exchanger illustrated in FIG. 2 ;
[0013] FIG. 4 is a top view of one end of the heat exchanger illustrated in FIG. 2 ; and
[0014] FIG. 5 is a partial bottom view of the header tank illustrated in FIG. 2 .
DETAILED DESCRIPTION
[0015] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. There is illustrated in FIG. 1 , a typical cooling and heating system for an automobile. A water cooled engine 10 is cooled by water flowing through a water circuit 12 . Hot water from engine 10 is sent to a radiator or heat exchanger 14 . A fan 16 draws air through radiator or heat exchanger 14 for cooling purposes. The water leaving heat exchanger or radiator 14 is routed back to engine 10 by water circuit 12 . Hot water from engine 10 is also sent to a heat exchanger 18 which is located within an air conditioning case 20 for heating a passenger compartment of the vehicle. The water returned from heat exchanger 18 is routed back to engine 10 by water circuit 12 . A pump 22 controls the flow of water within water circuit 12 .
[0016] An air conditioning system includes a compressor 30 which compresses refrigerant flowing through a refrigerant circuit 32 . Compressed refrigerant from compressor 30 is sent to a condenser or heat exchanger 34 which also receives air drawn by fan 16 . Refrigerant from condenser or heat exchanger 34 passes through an expansion valve 36 and then to an evaporator or heat exchanger 38 through refrigerant circuit 32 . Evaporator or heat exchanger 38 is also disposed within casing 20 and it is used to cool the passenger compartment of the vehicle. The refrigerant leaving evaporator or heat exchanger 38 flows through refrigerant circuit 32 and is sent to a gas/liquid separator 40 and from gas/liquid separator 40 , the refrigerant in gas form is drawn into compressor 30 .
[0017] Air-conditioning case 20 defines an air passage 42 through which air flows into the passenger compartment. An inside air inlet 44 for introducing air from inside the passenger compartment and an outside air inlet 46 for introducing air from outside the passenger compartment are provided at an upstream end of case 20 . An inside/outside air switching door 48 is located to open and close inlets 44 and 46 . A centrifugal blower 50 draws air in through inlets 44 and 46 and blows this air through evaporator 38 , and heat exchanger 18 located within air passage 42 and then into the passenger compartment. An air mixing door 52 adjusts the temperature of the air to be blown into the passenger compartment.
[0018] A face opening 54 blows air toward the upper portion of a passenger. A foot opening 56 blows air toward a lower portion of a passenger. A defroster opening 58 blows air toward a windshield of the vehicle for defrosting and defogging of the windshield.
[0019] Referring now to FIGS. 2-5 , heat exchanger or radiator 14 is illustrated in greater detail. While the present disclosure is being described using heat exchanger or radiator 14 , it is within the scope of the present invention to have heat exchanger 18 , condenser or heat exchanger 34 and evaporator or heat exchanger 38 incorporate the features of the present disclosure.
[0020] Heat exchanger or radiator 14 comprises a core portion 60 , a first tank member 62 and a second tank member 64 . Core portion 60 comprises a plurality of tubes 66 , a plurality of fins 68 , a pair of inserts or side plates 70 and a pair of core plates 72 .
[0021] Each of the plurality of fins 68 is a corrugated fin formed into a wave shape by bending a thin plate. The plurality of tubes 66 and the plurality of fins 68 are alternately stacked with each other. Inserts or side plates 70 are attached to the outermost fin on each side of core portion 60 to reinforce core portion 60 . Inserts or side plates 70 extend in the same longitudinal direction as the plurality of tubes 66 .
[0022] Each core plate 72 is provided with a plurality of tube holes 74 within which an end portion of the plurality of tubes are inserted. Each core plate 72 also includes a pair of insert or side plate holes 76 within which a respective insert or side plate 70 is inserted. Each core plate 72 also defines a generally rectangular sealing surface 80 which extend along the two longitudinal edges of core plate 72 and extends between the outermost tube holes 74 and the insert or side plate holes 76 . In addition, each core plate 72 has a tank insertion portion 82 at its outer peripheral portion within which an outer peripheral portion 84 of first and second tank members 62 and 64 are inserted so that a tank space 86 communicating with the plurality of tubes 66 is formed. A seal 88 interfaces between sealing surface 80 of core plate 72 and outer peripheral portions 84 of tank members 62 and 64 to seal tank space 86 from the outside environment. Furthermore, a plurality of claw portions 90 are located along the outer periphery of each core plate 72 . Claw portions 90 are crimped over to maintain the attachment of tank members 62 and 64 to their respective core plate 72 .
[0023] First and second tank member 62 and 64 are preferably made of a resin material such as a nylon material including glass fiber to have heat resistance and strength sufficient for the application. While tank members 62 and 64 are described as being made of a resin, other materials for tank members 62 and 64 can be utilized. Each tank member 62 and 64 is formed into an approximate U-shape in cross section. The open end of the U-shape faces its respective core plate 72 . A plurality of ribs 92 are spaced along the smaller end wall of each tank member 62 and 64 to provide additional stiffness to tank members 62 and 64 and thus preventing any warping.
[0024] An inlet pipe 94 and an outlet pipe 96 are provided in tank members 62 and 64 to allow for the inflow and outflow of coolant. Additionally, a cooling filling port 98 is provided in tank member 62 for maintaining the supply of coolant in the system.
[0025] Referring to FIG. 3 , the insert or side plate holes 76 are located at a position outside of the tank space 86 . An insert or side plate pocket 110 is defined by each side of each header tank 62 and 64 . Each end of each insert or side plate 70 extend through a respective insert or side plate hole 76 . The end of insert or side plate 70 can be inserted through the respective insert or side plate hole 76 without any retention device, or a retention device such as a light brazing can be utilized to secure the connection. Each insert of side plate 70 is brazed to the adjacent fin 68 so movement of insert or side plate 70 with respect to the remainder of core portion 60 is prohibited.
[0026] The separation of the connection of each insert or side plate 70 and the connection of each tube 66 with core plates 72 eliminates the thermal stress and the associated problems in cold ambient temperatures with hot fluid running through tubes 66 .
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A heat exchanger has a plurality of tubes and a plurality of fins alternatively arranged to define a core portion of the heat exchanger. A side plate is arranged at opposite sides of the core portion. Each end of the tubes and side plates extend through a core plate. Each core plate mates with a respective tank to define a sealed chamber. The ends of the tubes are disposed within the sealed chamber. The ends of the side plates and disposed outside the sealed chamber. This allows for a non-brazed connection between the core plates and the side plates.
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FIELD OF THE INVENTION
The present invention relates generally to an image processing apparatus, and more particularly, to an image processing apparatus for processing both a continuous-tone image and a two-tone image in a digital manner.
BACKGROUND OF THE INVENTION
Conventionally, various image processing apparatus for processing images in a digital manner have been developed. In the image processing apparatus, it is simple to binarize two-tone images, such as coded data images, graphic images and character images. That is, the two-tone images can be simply binarized in reference to a prescribed threshold value. Generally, the system is called a simple binarization system. However, it is rather difficult to binarize continuous-tone images, such as photograph images. Thus, many techniques or systems for binarizing the continuous-tone images, e.g., a quasi gradation system such as a dither system, have been proposed. The dither system operates to minimize a distortion of image data.
However, both the binarizations of the two-tone images and the continuous-tone images (the images will be referred to as character images and photograph images, hereafter) are mutually inconsistent. That is, a gradation of the photograph images is deteriorated when the simple binarization system is employed. On the other hand, a resolution of the character images is deteriorated when the quasi gradation system is employed. Thus, in the practical apparatus the two systems are selectively employed by a manual selection. However, either the character images or the photograph images are inevitably damaged when the character images are and the photograph images mixedly present on the same document.
To solve the problem, an Error Diffusion System has been proposed in the article "An Adaptive Algorithm for Spatial Grey Scale" in the magazine titled "Proceeding of the S.I.D.", Vol. 17/2 Second Quarter 1976, pp. 75-77. This system has made the requirements of the gradation of the photograph image and the resolution of the character image be compatible. That is, according to the Error Diffusion System binarization, errors occurring in a binarizing process of every pixel which is actually processed (the actually processed pixel will be referred to as subject pixel hereafter) are diffused on other pixels around the subject pixel after the binarization errors were each multiplied with a predetermined weighting factor.
However, a problem still exists with the Error Diffusion System when the continuous-tone images and the two-tone images are mixedly present on a same document because a resolution of the two-tone images is deteriorated.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an image processing apparatus which is capable of satisfying the binarization of both the continuous-tone images and the two-tone images.
Another object of the present invention is to provide an image processing apparatus which is capable of promoting efficiency of the binarization processes for both the continuous-tone images and the two-tone images.
In order to achieve the above object, an image processing apparatus according to one aspect of the present invention includes an input circuit for receiving image data, a binarizing unit for binarizing a subject pixel of the image data supplied from the input circuit, an error detector for detecting an error between a binarized image data obtained by the binarizing unit and the image data supplied from the input circuit, an error diffusing circuit for diffusing the error on other image data associated with other pixels around the subject pixel, a compensating unit for compensating the image data of the subject pixel by using a compensation data which is caused by a previous error diffusion of the error diffusing circuit, a circuit for detecting an image density of the image data for a prescribed image area surrounding the subject pixel and a controller for controlling the compensating unit in response to the image density detected by the image density detecting circuit.
Additional objects and advantages of the present invention will be apparent to persons skilled in the art from a study of the following description and the accompanying drawings, which are hereby incorporated in and constitute a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a diagram showing a first embodiment of the image processing apparatus according to the present invention;
FIG. 2 is a block diagram showing the pixel density calculator in FIG. 1;
FIG. 3 is a timing chart showing the operation of a pixel density calculator of FIG. 2; and
FIG. 4 is a diagram showing a second embodiment of the image processing apparatus according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail with reference to the FIGS. 1 through 4. Throughout drawings, like or equivalent reference numerals or letters will be used to designate like or equivalent elements for simplicity of explanation.
Referring now to FIG. 1, a first embodiment of the image processing apparatus according to the present invention and its binarizing operation will be described in detail.
In FIG. 1, an image data D1 of the subject pixel is applied to a line buffer memory 26 through an input terminal 12. The image data D1 is read by an image reader (not shown) such as an image scanner. The line buffer memory 26 has memory areas for storing image data of pixels which are successively read. The area marked by * indicates a memory position for storing the image data of the subject pixel which is presently processed. The image data stored in the line buffer memory 26 is then applied to a compensator 10 through a delay unit 28. An operation of the delay unit 28 will be described later.
The compensator 10 compensates the image data D1 by adding the input image data D1 with a compensation data D2 which is also applied to the compensator 10. The compensation data D2 will be described later. A compensated image data D3 output from the compensator 10 is applied to a binarizing unit 14 and a binarization error detector 16. The binarizing unit 14 typically consists of a comparator to which a first threshold voltage Th1 is also applied. Thus, the binarizing unit 14 binarizes the compensated image data D3 by comparing the compensated image data D3 with the first threshold voltage Th1.
A binarized image data D4 output from the binarizing unit 14 is applied to the binarization error detector 16. The binarization error detector 16 typically consists of a subtractor. Thus, the binarization error detector 16 detects an error between the compensated image data D3 and the binarized image data D4 by subtracting the data D3 and D4 from each other. The error is output from the binarization error detector 16 as a binarization error data D5. That is, the binarization error data D5 is obtained according to the following equation:
D5=D3-D4 (1)
This binarization error data D5 is applied to a weighting unit 20. The weighting unit 20 typically consists of a multiplier to which a weighting factor storage 22 is coupled. The weighting factor storage 22 typically consists of a ROM (Read Only Memory). Some of the areas marked by A, B, C and D in the weighting factor storage 22 indicate positional relationships between a reference position associated to the subject pixel and memory positions which store weighting factors associated for four pixels in neighbor of the subject pixel in the direction that follows the subject pixel. Here, we assume that the marks A, B, C and D represent the respective weighting factors stored in the memory positions. The four weighting factors A, B, C and D are for example, defined as A=7/16, B=1/16, C=5/16 and D=3/16.
The weighting factors A, B, C and D are applied to the weighting unit 20. The weighting unit 20 then weights the weighting factors A, B, C and D on the binarization error data D5. That is, the weighting factors A, B, C and D are individually multiplied to the binarization error data D5. Thus, the weighted error data D6 consists of the following four data elements e A , e B , e C and e D which are calculated by the following equations;
e.sub.A =A×D5 (2)
e.sub.B =B×D5 (3)
e.sub.C =C×D5 (4)
e.sub.D =D×D5 (5)
Alternatively, these four elements can be obtained by a following method. That is, any one of four elements, e.g., the e D can be obtained by subtraction as follows, based on other three elements, i.e., the e A , e B and e C and e D after the three elements were obtained according to the equations (2), (3) and (4);
e.sub.D =D5-(e.sub.A +e.sub.B +e.sub.C) (6)
A weighted error data D6 consisting of four elements e A , e B , e C and e D is output from the weighting unit 20. The weighted error data D6 is applied to a compensation data storage 24.
The compensation data storage 24 typically consists of an accumulator (not shown) and a RAM (Random Access Memory). The compensation data storage 24 has areas for storing the compensation data D2, as described above. Some of the areas marked by *, c A , c B , c C and c D indicate memory positions which store compensation data associated for the subject pixel and its four neighbors in pixels which follow the subject pixel. Here, we assume that the marks *, c A , c B , c C and c D represent data stored in the memory positions.
When the weighted error data D6 is applied to the compensation data storage 24, the accumulator accumulates the four elements e A , e B , e C and e D on the data c A , c B , c C and c D . The accumulated data are again stored in the weighted error data D6. Thus, the previously stored data c A , c B , c C and c D are updated to the accumulated data every time that the weighted error data D6 is applied, according to the following equations;
c.sub.A =c.sub.A +e.sub.A (7)
c.sub.B =c.sub.B +e.sub.B (8)
c.sub.C =c.sub.C +e.sub.C (9)
c.sub.D =c.sub.D +e.sub.D (10)
These accumulations of the weighted error data D6 are repeated for every subject pixel. Thus the data * stored in the memory position associated to the subject pixel takes a resulted data of continuous accumulations carried out for four previously processed pixels. In other words, the data * in the compensation data storage 24 is reflected by binarizing errors of the four previously processed pixels.
The data * in the compensation data storage 24 is read as the above-mentioned compensation data D2 and then applied to a gate 30 which will be described in detail later.
On the other hand, the line buffer memory 26 is coupled to an image density detector 32. The image density detector 32 detects an image density at a prescribed image area surrounding the subject pixel *, e.g., the image area consisting of "4×4" pixels as shown by oblique line zone in the line buffer memory 26. An image density data D7 detected by the image density detector 32 is applied to a comparator 34. The comparator 34 compares the image density data D7 with a second threshold voltage Th2. Generally the image density data D7 is a relatively large value when continuous-tone images such as photograph images are processed. On the other hand, the image density data D7 is a relatively small value when two-tone images such as character images are processed.
The comparator 34 then outputs a discrimination data D8 which changes between "1" and "0", in response to the process of photograph images or character images. The discrimination data D8 output from the comparator 34 is applied to the control terminal of the gate 30. When the discrimination data D8 is "1" thus discriminating photograph images, the gate 30 allows the compensation data D2 to pass through. Then, the compensation data D2 from the compensation data storage 24 is applied to the compensator 10. On the other hand, when the discrimination data D8 is "0" thus discriminating character images, the gate 30 prohibits the compensation data D2 to pass through.
Accordingly, the compensation data D2 is selectively applied to the compensator 10 in response to whether the continuous-tone images such as photograph images are processed or the two-tone images such as the character images are processed. The discrimination is automatically carried out.
The above-mentioned delay unit 28 delays the image data D1 for a prescribed period. Thus, the image data D1 is applied to the compensator 10 synchronous with the compensation data D2 which is also applied to the compensator 10 through the gate 30.
Thus, the resolution of the character images from the deterioration due to the compensation data D2 is prevented.
Referring now to FIGS. 2 and 3, an example of the image density detector 32 will be described in detail. FIG. 2 shows the detail of the image density detector 32. FIG. 3 shows a timing chart for explaining the operation of the image density detector 32. This example of the image density detector 32 obtains the above-mentioned discrimination data D8 by detecting pixels with maximum and minimum values within a prescribed image area surrounding the subject pixel *, e.g., the image area consisting of "4×4" pixels (see FIG. 1).
In FIG. 2, all the image data stored in the line buffer memory 26 in association with the image area consisting of "4×4" pixels are consecutively applied to a distributor 32a synchronous with a clock signal CLK (see FIG. 3). We assume that each image data has a bit size of 8 bit/pixel.
First, a set of four image data associated with four pixels along the row direction, e.g., four image data associated with the pixels along the first row of the "4×4" matrix (see FIG. 1) are applied to the distributor 32a through its first input terminal I0. The distributor 32a distributes the first set of the image data to a first comparator 32b through its output terminals A0, A1, A2 and A3. The distributing operation of the distributor 32a is managed by two control signals SE1 and SE2. These two control signals SE1 and SE2 are generated from the clock signal CLK by a 2-bit counter 32c.
The first set of the four image data along the row direction are compared with each other in the first comparator 32b. Thus, the first comparator 32b outputs the maximum value and the minimum value in the first set of the four image data through its output terminals MAXb and MINb, respectively.
Similarly, second, third and fourth sets of four image data which are associated with the pixels along the second, third and fourth rows of the "4×4" matrix are applied to the distributor 32a through its second, third and fourth input terminals I1, I2 and I3. These three sets of image data are consecutively distributed to second, third and fourth comparators 32d, 32e and 32f following the first set of the image data, respectively. Each of the comparators 32d, 32e and 32f also outputs the maximum value and the minimum value in the second, third or fourth set of the four image data.
All of the maximum values output from the first through fourth comparators 32b, 32d, 32e and 32f are applied to a fifth comparator 32g at the timing of FTR1 (see FIG. 3). Thus, the fifth comparator 32g outputs the maximum value in the maximum values applied thereto through its output terminal MAXg. On the other hand, all of the minimum values output from the first through fourth comparators 32b, 32d, 32e and 32f are applied to a sixth comparator 32h at the timing of FTR1 (see FIG. 3). Thus, the sixth comparator 32h outputs the minimum value in the minimum values applied thereto through its output terminal MINh.
The maximum value and the minimum value output from the fifth and sixth comparators 32g and 32h represent the maximum density Dmax and the minimum density Dmin of the image in the "4×4" matrix. The maximum value Dmax and the minimum value Dmin output from the fifth and sixth comparators 32g and 32h are applied to a subtractor 32i.
The subtractor 32i subtracts the minimum density Dmin from the maximum density Dmax. Thus, the difference between the maximum value Dmax and the minimum value Dmin, which represents the maximum density difference ΔDmax of the image in the "4×4" matrix is obtained by the subtractor 32i, according to the following equation:
ΔDmax=Dmax-Dmin (11)
The maximum density difference ΔDmax is applied to the comparator 34 as the above-mentioned image density data D7 (see FIG. 1).
According to the first embodiment of the image processing apparatus of the present invention, it is possible to binarize only the continuous-tone images such as the photograph images by automatically responding to the continuous-tone images. Accordingly, it is prevented that the deterioration of the resolution of two-tone images such as character images due to the two-tone images being evenly binarized is prevented. Thus, even if the continuous-tone images and the two-tone images are mixedly presented on a same document it is possible to suitably process the different types of images in response to the image density of the images.
In the first embodiment, various data such as the image data D1 through D6 are provided for processing for every pixel. However, the data can be provided for processing an image ranging in the matrix of "N×N" pixels (N represents an integer more than 2). According to this modification, the image processing speed can be increased.
Further, although the maximum density difference ΔDmax is used to distinguish the continuous-tone images and the two-tone images in the above embodiment, special pixel density data which has a different nature for a photograph part and a character part, such as a standardized maximum density difference, that is, a value obtained by dividing maximum density difference with a mean density or Laplacian value which is a secondary differential value of image, may be used.
Referring now to FIG. 4, a second embodiment of the image processing apparatus according to the present invention will be described. This embodiment of the image processing apparatus has a construction almost the same as the first embodiment except that the gate 30 in the first embodiment is replaced by a compensation data adjuster 36. Thus, then the image density detector 32 is directly coupled to the compensation data adjuster 36 without passing through a comparator 34.
Accordingly, in regard to the second embodiment the compensation data adjuster 36 and its related portions will be described herein-below but other portions the same as those of the first embodiment will be omitted.
In FIG. 4, the compensation data adjuster 36 receives the compensation data D2 from the compensation data storage 24. Further, the compensation data adjuster 36 receives the image density data D7 from the image density detector 32. The compensation data adjuster 36 adjusts the compensation data D2 according to the image density data D7 from the image density detector 32. Thus, an adjusted compensation data D9 is applied from the compensation data adjuster 36 to the compensator 10. The input image data D1 from the line buffer memory 26 is compensated at the compensator 10 by the adjusted compensation data D9 and then supplied to the binarizing unit 14.
Now the calculation carried out in the compensation data adjuster 36 for obtaining the adjusted compensation data D9 will be described in detail. The compensation data adjuster 36 normalizes the image density data D7 from the image density detector 32, i.e., the maximum density difference ΔDmax. Thus, the maximum density difference ΔDmax ranges in "0" through "1". The compensation data adjuster 36 then calculates the adjusted compensation data D9 according to the following equation:
D9=D2×(1-(ΔDmax)norm) (12)
wherein (ΔDmax)norm represents the normalized data of the maximum density difference ΔDmax.
The maximum density difference ΔDmax is large when the two-tone images such as the character images is processed. Thus, the adjusted compensation data D9 is a small value, as easily understood from the equation (12). On the other hand, the maximum density difference ΔDmax is small when the continuous-tone images such as the photograph images is processed. Thus, the adjusted compensation data D9 is a large value, as also understood from the equation (12).
In the second embodiment, the adjusted compensation data D9 is applied to the compensator 10 for compensating the input image data D1 in place of the compensation data D2. Further, the adjusted compensation data D9 is a compensation data adjusted by the normalized data of the maximum density difference ΔDmax which varies in response to the image density. Thus, the adjusted compensation data D9 can be used for processing any kind of images. That is, the adjusted compensation data D9 can compensate image data of all kinds of images including the continuous-tone images such as the photograph images and the two-tone images such as the character images.
In the second embodiment, the adjusted compensation data D9 can be obtained in accordance with the following equation in place of the equation (12):
D9=D2/ΔDmax (13)
Furthermore, any other calculations are possible for obtaining the adjusted compensation data D9. For example, "maximum density difference/average density" or a Laplacian value representing a second order differentiation of image data can be used in the equations (12) and (13) in place of the "ΔDmax" and "(ΔDmax)norm2.
Further, although in the above embodiments the input image data are binarized by the binarizing unit 14, it is possible to code the input image data to multilevel image data by using a coding unit with multiple threshold voltages. Then, multilevel printers which are able to print continuous-tone images can print the multilevel image data. Further, in this invention the detection of image density in the image density detector 32 is carried out by using an amount of optical reflections of image data. However, it is possible to convert the amount of optical reflections into a logarithm of its reciprocal and then use the converted data for detecting the image density. It is also possible to add human visual characteristics in the conversion.
As described above, the present invention can provide an extremely preferable image processing apparatus capable of promoting picture quality by performing the binarization of image data corresponding to its image and furthermore, promoting process efficiency in various image processes by performing processes corresponding to pixel densities.
While there have been illustrated and described what are at present considered to be preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the present invention without departing from the central scope thereof. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the present invention, but that the present invention include all embodiments falling within the scope of the appended claims.
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An image processing apparatus including an input circuit for receiving image data, a binarizing unit for binarizing a subject pixel of the image data supplied from the input circuit, an error detector for detecting an error between a binarized image data obtained by the binarizing unit and the image data supplied from the input circuit, an error diffusing circuit for diffusing the error on other image data associated with other pixels around the subject pixel, a compensating unit for compensating the image data of the subject pixel by using a compensation data which is caused by a previous error diffusion of the error diffusing circuit, a circuit for detecting an image density of the image data for a prescribed image area surrounding the subject pixel and a controller for controlling the compensating unit in response to the image density detected by the image density detecting circuit.
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GOVERNMENT INTEREST
[0001] This invention was developed in part under a Phase II Small Business Innovation Research Contract.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention relate to high velocity engines and projectiles. More particularly, embodiments of the invention relate to testing procedures and apparatuses for high velocity engines and projectiles.
[0004] 2. Description of Related Art
[0005] Ramjet and supersonic combustion ramjet (scramjet) technology has been the subject of extensive research and development. In this application, the term ramjet is intended to include scramjets, where appropriate. Scramjet engines provide propulsion at hypersonic speeds (i.e. above Mach 5) by capturing atmospheric air to bum onboard fuel. For hypersonic propulsion, these air breathing engines are more efficient than rocket motors and can allow longer duration hypersonic flight with greater payload.
[0006] Testing scramjet engines has, in the past, been an extremely expensive undertaking. This is due to the need to accelerate a scramjet to its takeover velocity, the velocity at which the engine begins to be able to operate. The takeover velocity is at supersonic or hypersonic speeds. One mainstream thought regarding methods of accelerating a scramjet engine to the takeover velocity involves a first stage vehicle being lifted to flight level by a jet aircraft and released. The first stage vehicle then accelerates the scramjet vehicle beyond the takeover velocity, at which point the scramjet engine ignites and testing can begin. The costs associated with one such test can be on the order of magnitude of $10 million. The high cost of such testing has proved to be prohibitive in many cases, resulting in insufficient testing of scramjet technology.
[0007] As a low cost alternative, it has been proposed to use a gas gun to accelerate to supersonic speeds a projectile having a scramjet engine. Many problems exist with the prior art ramjet test projectile and with methods for launching such a ramjet test projectile from a gas gun. For example, the acceleration forces to which a ramjet, and particularly a scramjet, projectile is subjected during a gas gun launch is more than 5000 G's and is more typically on the order of 10,000 G's, that is, 10,000 times the force of gravity, or more. Launches from other types of guns can subject a scramjet or other projectile to 60,000 or 70,000 G's. At accelerations as high as these, the projectile must be G-hardened to withstand the loads resulting from the acceleration. Conventional mechanical fasteners often used in the prior art cannot withstand such forces. Moreover, the basic structural design of prior art ramjet projectiles is incapable of withstanding such forces. Prior ramjet test projectiles typically include a heavy center body surrounded by a cowl. Thin pylons are used to hold the center body and cowl together. When a projectile having such a construction is subjected to the high acceleration forces present during gun launch, the thin pylons break and the test projectile disintegrates.
SUMMARY OF THE INVENTION
[0008] A projectile structure is provided. In an exemplary embodiment, the projectile structure comprises a cowl and a center structure. A plurality of wide pylons connects the cowl to the center structure. At least one engine is provided, the engine being located between adjacent pylons. The cowl, the center structure and the plurality of pylons form an integral structure. The pylons define, in part, the inlet to the engine, providing side wall compression to a fluid provided to the engine.
[0009] Embodiments of the invention greatly increase the feasibility of ramjet, and particularly scramjet, technology research and development. By using a gas gun to launch a scramjet projectile, embodiments of the invention reduce the launch cost of a scramjet projectile by two orders of magnitude compared to aircraft-released and/or rocket acceleration.
[0010] Exemplary embodiments of the present invention overcome the problems in the prior art. Embodiments of the invention use strong materials, such as titanium, for the projectile. The scramjets of the invention have a basic structure formed from a single piece or constructed from a small number of parts connected securely, such as by welding or threaded connections. For example, particular embodiments of the invention are constructed from four titanium parts welded together.
[0011] Exemplary embodiments of the present invention utilize wide pylons as structural members of the projectile. The use of wide pylons as structural members is enabled by also using the pylons to form part of the scramjet engine inlet. Otherwise, wide pylons would adversely affect engine performance. When used as part of the scramjet engine inlets, the pylons provide tangential compression to the inlet airflow. The arrangement of the pylons at the inlet, along with a tapered fore body, provides a radial and tangential flow to incoming air, that is, flow of air radially outward from the longitudinal axis of the scramjet and in directions tangential to the scramjet. Thus, the arrangement of the pylons in the scramjet according to the present invention provides a three-dimensional airflow. The three-dimensional air flow leads to improved scramjet performance compared to the two-dimensional air flow achieved by the high aspect ratio slit used for the inlet flow area in the prior art. Thus, the structure and design of the pylons in the present invention provide structural integrity to the test projectile, as well as improved scramjet engine performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view of a projectile structure in accordance with embodiments of the invention;
[0013] [0013]FIG. 2 is a sectional view of an embodiment of the invention shown in FIG. 1;
[0014] [0014]FIG. 3 is a front view of the embodiment of the invention shown in FIG. 2;
[0015] [0015]FIG. 4 is a rear view of the embodiment of the invention shown in FIG. 2;
[0016] FIGS. 5 - 8 are schematic views of an example of a testing apparatus of the invention; and
[0017] [0017]FIG. 9 is a rear view of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIGS. 1 - 4 show an example of a scramjet projectile in accordance with an embodiment of the invention. As can be seen from FIGS. 1 and 2, a projectile structure 100 has primary structural members including: a conical fore body 110 , a center body 114 , an aft body 125 , together defining a center structure, and an annular member, or cowl, 140 . The conical fore body 110 is connected to the center body 114 . The conical fore body 110 includes an external surface 115 extending from its tip towards the cowl 140 . The external surface 115 is configured to compress the fluid (air) through which the projectile passes. The aft body 125 is connected to the center body 114 at an end opposite the conical fore body 110 . A plurality of pylons 120 extend radially from the center body 114 and aft body 125 to the cowl 140 . The pylons serve to segregate adjacent internal flow passages 200 , each of which is part of a respective scramjet engine. The cowl 140 encloses the scramjet engines. In this example, each pylon 120 has a leading edge 124 , two side surfaces 126 and an aft end adjacent to the aft end of the projectile structure 100 . The flow passages 200 are each defined by side surfaces 126 of adjacent pylons 120 , center body 114 , aft body 125 , and cowl 140 . Although described herein as separate members connected together by, for example, welding or threaded connections, the fore body 110 , the center body 114 , the aft body 125 and the pylons 120 , or combinations thereof, can be formed as a monolith, that is, a single piece, for example, by casting or by machining a billet.
[0019] Two flow passages 200 are shown in cross-section in FIG. 2. The flow passages 200 extend longitudinally through the projectile. Inlets 190 to flow passages 200 are each defined by leading portions of side surfaces 126 of adjacent pylons 120 and by center body 114 . The inlets 190 are preferably not enclosed by the cowl 140 . As shown in FIG. 3, leading portions of side surfaces 126 of adjacent pylons 120 are arranged opposite each other to define inlets 190 . The side surfaces 126 of the pylons 120 are arranged to converge toward opposing side surfaces of adjacent pylons and thereby provide sidewall compression to the air entering inlet 190 . Accordingly, the air entering the inlet of flow passages 200 is compressed by the external surface 115 of the conical fore body 110 and also by leading portions of the side surfaces 126 of the pylons 120 . Preferably, the external surface of the conical fore body 110 and leading portions of the side wall surfaces 126 are configured to have certain angles to compress and turn the air as it enters the inlets 190 , thus, raising the pressure of the air flow.
[0020] In the illustrated embodiment, the pylons 120 and the leading edge of cowl 140 define notches 130 at the inlets 190 . The notches 130 here are V-shaped and have leading points 134 , at the leading edges 124 of the pylons 120 , and rear points 132 . The notches 130 may have other shapes, for example, U-shape, elliptical or hyperbolic, but are usually generally scalloped in shape. The objective of the shape of the leading edge of the cowl 140 is to achieve a shock wave at the rear points 132 for the design Mach number, and allow self-starting inlet. The leading edge of the cowl 140 is arranged to intersect a conical shock wave set up by the conical fore body 110 . The shapes of the notches 130 are designed such that the leading edge of the cowl 140 also conforms to planar shock waves set up by the leading portions of the side wall surfaces 126 of the pylons 120 . These provisions maximize the performance of the engines. Each notch 130 is the leading edge of an exterior surface 210 . Although exterior surfaces 210 are shown as having both concave and convex surfaces, other shapes for exterior surfaces 210 are also appropriate.
[0021] Utilizing the pylons 120 to compress the incoming air flow allows the pylons to be made wider than in prior art scramjet projectiles. In previous projectile structures, wide pylons would have inhibited air flow into the scram jet engines and affected the performance of the engines. However, by using the pylons to compress the air entering the engines in accordance with the present invention, it is possible to have wide pylons that provide structural integrity to the projectile. For example, a profile width of the pylons 120 , the width between adjacent flow passages at the throat of the flow passages, can be made as great as and even greater than a profile width of the engines, the width of the flow passages 200 between adjacent pylons 120 being from 1 to 12 times as great, preferably 2 to 5 times as great. These relative widths, as described, are taken at the throat, the minimum flow area of the flow passages 200 . Pylons having such thicknesses provide the structural integrity needed for the test projectile to withstand the high acceleration forces, G forces, generated during gas gun launch. The key is to have wide pylons to give structural integrity while at the same time using those wide pylons constructively to yield high engine performance.
[0022] [0022]FIG. 3 is a frontal view of the projectile structure 100 shown in FIGS. 1 and 2. FIG. 4 is a rear view of the projectile structure 100 shown in FIGS. 1 and 2. As can be seen from FIGS. 1, 3 and 4 , the illustrated embodiment has eight pylons 120 and eight flow passages 200 . As can be seen from FIGS. 3 and 4, the thickness of the pylons 120 in a circumferential direction about the center line of the projectile structure is preferably greater than the width of the flow passages 200 along the same direction. As discussed further below, in alternate embodiments, this relatively large volume of the pylons 120 , can be used, in part, for additional storage. For example, if the pylons 120 are made hollow adjacent leading edges 124 , these volumes can be used to store fuel or munitions, including explosives, 215 , or boosters 400 (FIG. 9).
[0023] As can be seen in FIGS. 2 and 4, each flow passage 200 has at its rearmost portion a nozzle 150 . In addition, each flow passage 200 has a flame holder 160 and fuel supply ports 170 . Primary storage area 180 is provided in aft body 125 . Fuel can be stored in primary storage body 180 and supplied to each of the flow passages 200 by fuel valve 220 and fuel system 230 . Fuel valve 230 may be an inertially activated valve of a known type that is triggered by high G forces to allow fuel to flow. The fuel can be a compressed or liquefied gas or a solid fuel. In this example, fuel system 230 supplies fuel through apertures 240 and passages (not shown) through the center body 114 and the pylons 120 to fuel supply ports 170 in the pylons. The throat of each flow passage 200 is preferably located upstream of the point at which fuel is introduced into the flow passage. Also shown in FIG. 2 is a secondary storage volume 190 , which can store, for example, additional fuel, navigational or communications instrumentation, or munitions.
[0024] In operation, air is compressed, turned and introduced to flow passages 200 . As discussed above, the pylons 120 are arranged to provide side wall compression. The turning of the air is performed by the pylons 120 and conical fore body 110 , with the pylons preferably providing about two-thirds of the turning and the conical fore body 110 providing the remaining one-third. The external surface of the conical fore body 110 can have an angle, from the longitudinal axis to the surface, of, for example, about 8 degrees to perform compression and turning of the air.
[0025] The temperature of the air rises due to the heat of compression. As the compressed air passes fuel supply ports 170 , fuel is introduced by fuel supply ports 170 and ignited, for example, by spontaneous combustion due to compression or by other ignition. As the burning air/fuel mixture progresses along flow passages 200 , it expands and exits projectile structure 100 through nozzles 150 , thereby creating thrust to move the projectile forward. In the illustrated embodiment, each flow passage 200 is an independent scramjet engine. The fuel supply ports 170 of all of the flow passages 200 can be controlled together so that, when fuel flows, it flows to all of the flow passages simultaneously. Thus, the outputs of all of the engines can be controlled together. In preferred embodiments, the fuel supply ports 170 of each flow passage 200 are independently controlled so that the amount of thrust generated by each flow passage is controllable independently of the thrust of other flow passages. As a result, the output of each engine is controllable independently, and the projectile structure 100 can be steered during flight by independently controlling the amount of fuel supplied to each flow passage 200 .
[0026] FIGS. 5 - 8 illustrate an example of a testing apparatus 300 used to economically test ramjet and scramjet technology. The testing apparatus is able to simulate flight and operation of the scramjet test projectile at altitude. A two-stage gas gun 305 employing a light gas may be used as the testing apparatus. The gas gun 305 is used to accelerate the test projectile to supersonic speeds necessary to test the scramjet engines. The gas gun 305 has a pump tube 310 in which a piston 320 is arranged. The piston 320 moves in the longitudinal direction of pump tube 310 . A gun barrel 330 is connected to pump tube 310 by a transitional section 315 . Transitional section 315 transitions between the cross-sectional area of pump tube 310 and the smaller cross-sectional area of gun barrel 330 . The gun barrel has, for example, a diameter of about 4-8 inches and a length of about 80-130 feet.
[0027] Gun barrel 330 is connected to a blast tank 340 , which is, in turn, connected to a range tank 350 . A membrane 360 separates blast tank 340 and range tank 350 . When the gas gun is fired, the air in the gas gun gets extremely hot. An inert gas should be provided in blast tank 340 to prevent any unwanted combustion during the firing of the gun. The air pressure in range tank 350 is reduced to simulate flight at altitude, for example, about 100,000 feet. Membrane 360 may include a fast acting valve that opens to allow the test projectile to pass through, then closes quickly to maintain the separation between blast tank 340 and range tank 350 .
[0028] In operation, the test projectile 100 is arranged in gun barrel 330 . Piston 320 is accelerated to the right in FIG. 5 to compress a light gas in pump tube 310 . Examples of the gas that can be used in pump tube 310 are hydrogen and helium. Piston 320 can be accelerated by, for example, a gunpowder explosion behind piston 320 (to the left of piston 320 in FIG. 5) or any other appropriate means. FIG. 6 shows piston 320 being moved toward the right and compressing the gas in pump tube 310 . Projectile structure 100 begins to move to the right under the force created by the compressed gas in pump tube 310 . The test projectile may have a full bore structure. Therefore, some means of preventing the light gas from passing through the flow passages 200 of projectile 100 is preferably used. For example, a pusher plate 325 can be used behind projectile structure 100 between projectile structure 100 and the light gas. Alternatively, some means of protecting the rear and/or sides of projectile structure 100 (and possibly gun barrel 330 ) can be used. An example of such protection is a sabot 328 , shown in FIG. 6. Sabots also provide a means to distribute the launch load onto a larger area of projectile structure 100 . The pusher plate 325 or the sabot 328 , whichever is used, separates from the projectile structure 100 at some point after the projectile structure exits the gun barrel 330 . FIG. 7 shows piston 320 at its rightmost position and projectile structure 100 moving toward the right in gun barrel 330 . Projectile 100 is preferably accelerated to takeover velocity in gun barrel 330 . Projectile 100 then exits gun barrel 330 and proceeds through blast tank 340 and down range tank 350 . FIG. 8 shows projectile structure 100 piercing membrane 360 after exiting gun barrel 330 .
[0029] Instrumentation 370 is provided to detect and record the position of projectile 100 versus time during its flight through blast tank 340 and range tank 350 . The instrumentation 370 can include x-ray stations to determine not only position vs. time, but also the structural integrity of the projectile. The instrumentation can also include photo stations for taking laser-illuminated digital photographs of the projectile; infrared stations to take infrared images of the exhausts of the engines, to determine engine efficiency; stations for ultraviolet imaging and shadowgraphs; and high speed video cameras, such as those produced under the trademark HYCAM. Projectile structure 100 may also be provided with instrumentation. The instrumentation included with projectile structure 100 can include RF transmitting/receiving capability in order to provide from the test projectile information concerning pressure, temperature, acceleration, etc. Both the instrumentation 370 and the instrumentation of the projectile structure record information about the performance of the projectile and its engines. The flight of projectile structure 100 is concluded as it impacts endwall 354 of range tank 350 .
[0030] Although the method of testing according to the present invention has been described in connection with a gas gun employing a light gas, it is understood that the method is applicable to other guns, such as large military guns.
[0031] As mentioned above, the relative thickness of pylons 120 in preferred embodiments of the invention provide space that can be used to store, for example, fuel, munitions, instrumentation, booster engines or other appropriate material. As discussed above, ramjet and scramjet engines must reach a takeover velocity (usually Mach 2 or greater) before they will operate. In certain embodiments of the invention, pylons 120 can be made hollow in order to allow placement of a booster, for example a solid or other rocket booster, that can be used to accelerate the ramjet or scramjet engine up to the takeover velocity. A booster can be provided in each pylon or only in selected pylons. For example, if the projectile structure 100 has eight pylons, any number from one to eight boosters may be used. However, it is preferable to space the boosters symmetrically so as to more easily create symmetrical thrust. FIG. 9 shows a rear view of a projectile structure using a rocket booster 400 in each of eight pylons.
[0032] While the invention has been described with reference to particular embodiments and examples, those skilled in the art will appreciate that various modifications may be made thereto without significantly departing from the spirit and scope of the invention.
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A scramjet has a cowl, a center structure, and a plurality of wide pylons connecting the cowl to the center structure, with scramjet engines positioned between adjacent pylons. Leading surfaces of adjacent pylons converge to one another to provide side wall compression to air entering the engines. The center structure includes a fore body, a center body and an aft body that, with the pylons, define a basic structure either formed entirely from one piece or several securely connected pieces. A method of testing the scramjet projectile comprises using a gun to accelerate the scramjet projectile to the takeover velocity of the engines.
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This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 61/311,553, filed Mar. 8, 2010.
FIELD OF THE INVENTION
The present invention relates to a method of supporting an oxygen storage cylinder of the type commonly used for medical related breathing assistance, and more particularly the present invention relates to a support device arranged to secure the oxygen storage cylinder in an interior cabin of an aircraft.
BACKGROUND
Persons with various medical conditions are carry an oxygen storage cylinder with them for breathing assistance as needed. Various types of carriers for transporting a cylinder with a user are available. When boarding an airplane however, conventional carriers are not capable of adequately securing the cylinder in a safe manner which is protected from turbulence. Other alternatives include the user carrying the cylinder manually, however this is also unsafe and unprotected from turbulence. Some devices are intended to rigidly contain the cylinder, however, known attempts for supporting an oxygen cylinder in an aircraft involve rigid components which potentially wear against one another when exposed to the repeated vibrations in an aircraft so as to be also unsafe.
SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided a method of supporting an oxygen storage cylinder in an interior cabin of an aircraft, the method comprising:
providing an envelope of flexible material comprising a generally cylindrical wall portion extending in a longitudinal direction between opposing first and second ends and an end wall spanning the first end of the cylindrical wall portion, the second end of the cylindrical wall portion including an opening therein;
inserting the oxygen storage cylinder into the envelope of flexible material through the opening in the second end of the cylindrical wall portion such that the cylindrical wall portion surrounds the oxygen storage cylinder;
providing a plurality of circumferential straps secured to the cylindrical wall portion at spaced apart positions in the longitudinal direction of the envelope;
positioning the envelope adjacent a frame assembly in the interior cabin of the aircraft which is fixed in relation to the aircraft; and
securing each circumferential strap to extend fully about a circumference of the cylinder in the envelope and about respective frame members of the frame assembly adjacent to the envelope.
By providing an envelope of flexible material which fully surrounds an oxygen storage cylinder and which couples straps circumferentially thereabout, an oxygen storage cylinder can be well secured in relation to a fixed frame of the aircraft while also protecting the cylinder from damage or wear in the environment of an aircraft.
Preferably a first end strap is coupled to the first end of the envelope and the first end strap is secured about a respective frame member of the frame assembly.
Preferably a fixed end of the first end strap is anchored to the first end of the envelope and an opposing free end of the first end strap is secured to the cylindrical wall portion. In this instance, the free end of the first end strap may be overlapped with one of the circumferential straps.
A second end strap may be coupled to the second end of the envelope in which the second end strap is supported to extend diametrically across the opening in the second end of the envelope so as to retain the cylinder in the envelope.
The oxygen storage cylinder is preferably supported in the envelope such that a regulator valve supported on cylinder projects through the opening and the second end strap is secured across the opening such that the second end strap is wrapped at least partway about the regulator valve so as to retain the cylinder in the envelope.
Preferably two second end straps are coupled to the second end of the envelope such that each second end strap is supported to extend diametrically across the opening transversely to one another so as to retain the cylinder in the envelope.
When the oxygen storage cylinder is supported in the envelope such that a regulator valve supported on cylinder projects through the opening, preferably the second end straps are secured across the opening such that the second end straps are wrapped partway about opposing sides of the regulator valve and intersect one another so as to retain the cylinder in the envelope.
The free ends of the second end straps are also preferably overlapped by one of the circumferential straps so as to retain the cylinder in the envelope.
Preferably the flexible material of the envelope is positioned between the cylinder and each corresponding portion of the frame assembly such that the cylinder and frame assembly do not contact one another.
Two of the circumferential straps are preferably located adjacent respective ones of the opposing ends of the envelope and an additional intermediate one of the circumferential straps may be located about the envelope at a central location in the longitudinal direction.
When receiving a cylinder in the envelope which is shorter than the envelope, the method preferably includes: i) positioning a regulator valve of the cylinder to project through the opening of the envelope, and ii) securing the cylindrical wall portion to span a bottom end of the cylinder opposite the regulator valve at an intermediate location in the longitudinal direction of the envelope. In additional, diametrically opposed portions of the cylindrical wall portion are preferably joined to one another across the bottom end of the cylinder.
When providing the envelope in combination with first and second cylinders in which the second cylinder is shorter than the first cylinder, the method preferably includes:
receiving the first cylinder in the envelope such that the end wall spans a bottom end of the cylinder when a regulator valve of the first cylinder projects through the opening; and
alternately receiving the second cylinder in the envelope in place of the first cylinder by positioning a regulator valve of the second cylinder to project through the opening of the envelope and securing the cylindrical wall portion to span a bottom end of the second cylinder opposite the regulator valve at an intermediate location in the longitudinal direction of the envelope.
When the frame assembly of the aircraft comprises a seat frame supporting at least one passenger seat thereon, the method may include securing the circumferential straps about respective frame members of the seat frame.
When the seat frame further comprises a pair of spaced apart upright leg members and a crossbar extending between the upright leg members, the method may include securing the circumferential straps about the crossbar of the seat frame.
When there is provided a first end strap coupled to the first end of the envelope, the first end strap is preferably secured about a frame member oriented transversely to the crossbar.
When the frame assembly of the aircraft comprises a fixed seat frame supporting at least one passenger seat thereon, the method may further include:
securing the circumferential straps about a generally horizontal frame member of the seat frame;
providing a first end strap coupled to the first end of the envelope, and
securing the first end strap about an upright frame member of the seat frame which is oriented transversely to the generally horizontal frame member.
A pocket formed of transparent material may also be supported on an exterior of the cylindrical wall portion for supporting technical data relating to the cylinder in the pocket.
One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the support device together with an oxygen storage cylinder.
FIG. 2 is a perspective view of an open end of the envelope.
FIG. 3 is a perspective view of the end wall opposite the open end of the envelope.
FIG. 4 is a front elevational view of the device supporting a cylinder in fixed relation to a seat frame of an aircraft.
FIG. 5 is an end elevational view of the device supporting a cylinder on the seat frame of FIG. 4 .
FIG. 6 is a plan view of the outer side of the cylindrical wall portion of the envelope when laid flat prior to assembly into a cylindrical structure.
FIG. 7 is a plan view of the inner side of the cylindrical wall portion according to FIG. 6 .
In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
Referring to the accompanying figures there is illustrated an oxygen storage cylinder support device generally indicated by reference numeral 10 . The device 10 is well suited for securing an oxygen storage cylinder 12 in fixed relation to the interior cabin of an aircraft.
In a typical aircraft a plurality of seat frame assemblies 14 are provided which each support a pair of occupant seats 16 thereon. In the illustrated embodiment, the seat frame assembly 14 comprises two leg frames 18 at laterally spaced apart ends of the frame assembly in which each leg frame 18 comprises a pair of leg members spaced apart at respective front and rear corners of the frame assembly. A crossbar 20 is shown spanning generally horizontally between the two front leg members. Diagonal braces 22 are also shown spanning diagonally between each front leg member and the corresponding rear leg member of each leg frame 18 . The crossbar 20 and the leg members at opposing ends thereof are accordingly oriented transversely to one another.
The device 10 generally comprises an envelope 24 suitable for receiving the cylinder therein. The envelope comprises a cylindrical wall portion 26 formed of a flat rectangular sheet of material as shown in FIGS. 6 and 7 with long sides sewn together to form the generally cylindrical structure which fully surrounds the cylindrical wall of the cylinder 12 . The cylindrical wall portion 26 is elongate in a longitudinal direction between a first end 28 and an opposing second end 30 .
A circular end wall 32 , also formed of flexible material, fully spans the first end 28 of the cylindrical wall portion to fully enclose the first end of the envelope.
An opening 34 is provided at the second end 30 which fully spans the end of the envelope so as to be identical in diameter to the cylindrical wall portion. The cylindrical wall portion is suitably sized to slidably receive the cylinder 12 through the opening 34 with the wall portion being closely fit about the cylinder 12 such that the cylinder is fully surrounded and protected by the flexible and somewhat resilient material forming the envelope. When the cylinder is received within the envelope and the envelope is supported in fixed relation to the seat frame assembly, the envelope forms a full barrier between the cylinder 12 and the frame assembly such that there is no contact therebetween.
At the second end 30 of the envelope there is provided two second end straps 36 mounted to the peripheral edge about the opening 34 . Each of the two end straps 36 are fixedly mounted at a fixed end to the interior surface of the cylindrical wall portion at circumferentially spaced positions at the same side as the wall portion in close proximity to one another. The second end straps 36 have a suitable length to extend diametrically across the opening 34 in use. The free ends of the two second end straps 36 include respective mating fasteners 38 thereon which are arranged to be joined to respective ones of the mating fasteners 40 provided at spaced positions on the outer surface of the wall portion at the second end 30 thereof diametrically opposite from the fixed ends of the end straps. The free ends of the two second end straps 36 are thus arranged to be fastened adjacent one another by a mating connection between the mating fasteners 38 and the mating fasteners 40 . In a preferred embodiment the mating fasteners comprise mating hook and loop fasteners with hooks being provided on one of the mating fasteners and loops being provided on the other one.
In a typical mounting configuration, the envelope is matched in size to a specific cylinder such that when the bottom of the cylinder abuts the end wall of the envelope the cylinder spans the full length of the envelope such that a regulator valve 42 of the cylinder projects through the opening 34 . In this instance, the two end straps are first crossed over with one another and then wrapped around opposing sides of the stem of the regulator valve 42 to permit again crossing over each other at a diametrically opposed side of the stem prior to fastening the free ends to the wall portion using the mating fasteners 38 and 40 . The two second end straps 36 each extend partway about the circumference of the stem of the regulator valve such that the two end straps together substantially fully surround the stem of the valve and are intertwined transversely to one another to effectively retain the cylinder within the envelope.
A handle strap 44 is also provided at the second end of the envelope which is generally U-shaped in construction in the form of a flexible strap anchored at opposing ends at circumferentially spaced positions about the peripheral edge of the opening on the inner surface of the cylindrical wall portion.
A first end strap 46 is provided at the first end of the envelope and includes a fixed end which is fixedly secured to the end wall at a central location thereon, for example by stitching and the like. An opposing free end of the first end strap includes a suitable mating fastener 48 thereon which can be selectively secured to a corresponding mating fastener 50 on the outer surface of the cylindrical wall portion adjacent the first end of the envelope. The mating fastener 48 on the free end of the first end strap 46 spans a considerable length of the first end strap and is much longer than the corresponding fastener 50 on the envelope such that the free end of the first end strap can be secured to the envelope at various adjustable positions in relation thereto which effectively adjusts the overall length of the first end strap 46 between the fastened ends thereof to accommodate wrapping about various different dimensions of frame members when securing the envelope to the frame assembly.
The device 10 further comprises three circumferential straps 52 mounted onto the outer surface of the cylindrical wall portion at longitudinally spaced positions therealong. In particular, two of the circumferential straps 52 are secured adjacent opposing first and second ends of the envelope, while an intermediate one of the straps 52 is secured to the wall portion at a central location between the two ends. Each of the circumferential straps 52 comprises a fixed end which is anchored onto the exterior of the cylindrical wall portion in fixed relation thereto, for example by stitching and the like. Each of the straps 52 has a sufficient length to be wrapped about the full circumference of the envelope more than once when a cylinder is received within the envelope.
Similarly to the previous straps, a mating fastener 52 is provided along an interior length of the circumferential straps adjacent the free end thereof. A corresponding mating fastener 56 is provided along an exterior length of the circumferential strap 52 such that when each circumferential strap is wrapped about a full circumference of the envelope or is wrapped about various dimensions of frame members together with the envelope, the mating fastener at the free end of each strap on the inner surface thereof is arranged to be aligned with the corresponding mating fastener on the exterior on the same strap while permitting the length between the fastened ends of the straps to be adjusted as may be desired.
At each of the opposed ends of the envelope, the circumferential straps 52 are arranged in longitudinal alignment with the corresponding mating fasteners to which the first and second ends straps are arranged to be secured such that once the end straps are secured by using their corresponding mating fasteners, the circumferential straps overlap the end straps and assist in further retaining the end straps in a secured configuration.
In the illustrated embodiment the envelope is shown to correspond to the length of a first cylinder 12 . Typically, the cylinders are available in a second length which is shorter than the first length shown. When mounting a second cylinder which is shorter than the first cylinder shown in FIG. 1 , the bottom end of the cylinder opposite the regulator valve is typically located approximately at an intermediate location near the intermediate circumferential strap when the regulator valve is similarly positioned to project through the opening at a second end of the envelope. To snugly secure the cylinder in the longitudinal direction relative to the envelope, two opposing sides of the cylindrical wall portion are joined together at the inner surface thereof such that the cylindrical wall portion spans across the bottom of the second cylinder which is shorter than the first cylinder shown in the drawings. A joining of the opposing sides is formed by a pair of mating fasteners 58 which are secured to the inner surface of the cylindrical wall portion as shown in FIG. 1 . The mating fasteners 58 are slightly misaligned in the longitudinal direction so as to permit the fastener on one side to be folded towards the fastener on the other side as the cylindrical wall portion spans across the bottom side of the shorter second cylinder. As described above with regard to previous mating fasteners, in the illustrated embodiment the mating fasteners 58 also comprise hook and loop fasteners arranged to be selectively mated with one another.
A transparent pocket 60 is provided on the exterior surface of the cylindrical wall portion to receive various information therein which can be visibly displayed through the transparent pocket. Typical information includes technical or safety data relating to the oxygen storage cylinder.
In a preferred arrangement as shown in FIGS. 4 and 5 , a cylinder is received within the envelope such that the envelope spans across the bottom side of the cylinder in direct contact therewith while the cylindrical wall portion spans the full length of the cylinder 12 such that the regulator valve of the cylinder projects through the opening at the second end of the envelope. The second end straps are crossed over one another and each wrapped partway about the stem of the regulator valve to fully surround the valve as the two second end straps span diametrically across the opening at the second end of the envelope and retain the cylinder in the envelope. The envelope is then positioned adjacent a frame assembly in the interior cabin in the aircraft which is fixed in relation to the aircraft such that wrapping each of the circumferential straps about the full circumference of the cylinder and respective ones of the frame members of the frame assembly serves to both retain the end straps in a secure mounted configuration as well as fixing the envelope and cylinder received therein in relation to the frame assembly. The first end strap 46 is typically wrapped about a frame member of the frame assembly, which is transverse to the frame members that the circumferential straps are wrapped about, prior to wrapping of the circumferential straps such that the circumferential strap at the first end of the envelope can overlap the first end strap as described above.
In the illustrated embodiment of a seat frame, the cylinder is positioned to span generally in the lateral direction of the seat frame assembly to span between the leg frames at opposing ends of the assembly. As shown, the second end of the envelope is nested between one of the upright leg members and a diagonal cross brace with the circumferential strap being strapped to a horizontal crossbar of the seat frame to retain the second end snugly nested within the leg frame. As shown in FIG. 4 , the first end strap at the opposing first end is wrapped about the opposing leg frame member which is abutted with the first end of the envelope and cylinder received therein to prevent displacement of the envelope in the lateral direction. The remaining circumferential straps are also wrapped about the horizontal crossbar which extends in the lateral direction. The circumferential straps effectively retain the position of the envelope alongside the horizontal crossbar while the first end strap is secured to an upright member transverse to the horizontal cross bar to prevent sliding displacement of the envelope along the crossbar in the lateral direction of the crossbar.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
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An oxygen storage cylinder is stored in an interior cabin of an aircraft by providing a generally cylindrical envelope of flexible material receiving the cylinder therein and securing the envelope to a fixed seat frame. Circumferential straps are secured to a cylindrical wall portion of the envelope at spaced apart positions along the length thereof for securing the envelope and cylinder therein to an elongate frame member of the seat frame. End straps secured to intersecting frame members prevent longitudinal sliding of the envelope and cylinder therein relative to the elongate frame member of the fixed seat frame. The envelope protects the cylinder from direct contact with the frame to prevent friction or vibration damage to the cylinder while fixing the position of the cylinder in the interior cabin for the safety of surrounding passengers in the event of turbulence.
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This application is a continuation of application No. 240,415, filed May 10, 1994, now U.S. Pat. No. 5,408,769.
BACKGROUND OF THE INVENTION
This invention relates to an electric iron and in particular to a control for the thermostat thereof.
Electric steam irons for household use employ a thermostat for regulating the temperature thereof. Typically, an electric heating element is in heat transfer relation with the soleplate to provide heat thereto. A thermostat senses the temperature of the soleplate and regulates the supply of electrical power to the heating element so that a desired operating temperature for the soleplate can be established.
Many present day electric irons use a rotary control knob that is operated by the user and is mounted on either the handle or the saddle portion of the housing of the iron to enable the user to establish a desired operating temperature for the iron. The rotary control knob is directly connected to the thermostat. Other irons known in the prior art use a linear motion control knob in lieu of a rotary control member to enable the user to adjust the set point of the thermostat. The linear motion of the control member is converted to rotary motion via such means as a rack and pinion system to obtain the desired adjustment of the thermostat. An example of the foregoing is described in U.S. Pat. No. 4,748,755.
The designs of the prior art are limited to simple control motions, e.g. rotary or linear and cannot be used if a complex motion is required.
The aesthetic styling of contemporary irons is becoming quite important as it has been found that the shape and appearance of an iron is an important feature in attracting consumer interest in the iron. The trend in styling an iron is to form the iron housing in rather complex shapes. Further, in irons of rather small size, it has been particularly advantageous to mount the user temperature control on the housing saddle.
Accordingly, it is an object of this invention to provide a user temperature control for the thermostat for an electric iron which can be employed with iron housings having rather complex shapes.
SUMMARY OF THE INVENTION
The foregoing object and other objects of the invention are attained in an electric iron comprising a soleplate and an electric heating element connected to the soleplate for providing heat thereto. A skirt is connected to the soleplate. A housing including a handle portion and a saddle portion is connected to the skirt. A thermostat is mounted on the soleplate for sensing the temperature thereof. An actuator is rotatably connected to the thermostat for establishing an operating temperature for the soleplate. A track is formed in the saddle portion of the housing. The track extends arcuately in a horizontal plane through the skirt and has a vertical slope. A control member is movably retained in the track. Linkage means interconnect the control member to the actuator for converting the combined arcuate and vertical movement of the control member to rotational movement of the actuator.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded perspective view illustrating the iron, the water cassette, and the base for the iron and cassette;
FIG. 1A is an exploded perspective view of the cassette and portion of the base illustrating further details thereof;
FIG. 2 is a side elevational view, partially in section, of the iron being placed on the base;
FIG. 3 is a view similar to FIG. 2 with the iron on the base;
FIG. 4 is a side elevational view of the iron, with parts broken away for clarity, illustrating the iron on the soleplate thereof;
FIG. 5 is a view similar to FIG. 4 with the iron on its heel rest;
FIG. 6 is a view similar to FIGS. 4 and 5 with the iron in the base;
FIG. 7 is a side elevational view of the iron, partially in section, with the iron on the soleplate;
FIG. 8 is an enlarged sectional view of the steam control assembly employed in the iron;
FIG. 9 is an exploded perspective view of the steam control assembly;
FIG. 10 is a side elevational view with parts broken away to illustrate a thermostat control used in the iron;
FIG. 11 is a top plan view of the iron further illustrating the thermostat control;
FIG. 12 is an enlarged sectional view of a portion of the iron illustrating the thermostat control;
FIG. 13 is a side perspective view of the iron with parts broken away to illustrate a spray nozzle assembly employed on the iron;
FIG. 14 is an enlarged perspective view of the spray nozzle assembly;
FIG. 15 is an enlarged perspective view of the nozzle assembly;
FIG. 16 is a side perspective view of the iron with parts broken away to illustrate a reservoir fill control for the iron;
FIG. 17 is a partial sectional view of the iron illustrated in FIG. 16;
FIG. 18 is an exploded perspective view of the iron and base illustrating details of the water reservoir of the iron; and
FIG. 19 is a plan view partially in section and partially broken away of the water reservoir.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the various figures of the drawing, a preferred embodiment of the present invention shall now be described in detail. In referring to the various figures of the drawing, like numerals shall refer to like parts.
Referring specifically to FIGS. 1, 1A, 2 and 3, there is shown an iron assembly 10 embodying the present invention. Iron assembly 10 includes an iron 11, a water cassette 16, and a base 14. Base 14 includes a generally planar platform member 15 terminating in a downwardly inclined portion 41 at its rear end. Base 14 includes an upwardly extending rim 17. Platform 15 includes three standoffs 18 formed from nonabrasive material such as rubber or the like. Standoffs 18 contact the bottom surface of soleplate 54 of the iron when the iron is placed on the base. As standoffs 18 are made from nonabrasive material, the standoffs will not scratch the surface of the soleplate. Further, the standoffs are made from high temperature resistant material so that the iron may be placed directly in base 14 immediately after ironing is discontinued.
Base 14 includes a pair of inwardly extending hook-like projections 20 formed at the top of rim 17 and located at the front of platform 15. Hook-like projections 20 extend into a groove 55 formed between the top of soleplate 54 and the bottom of skirt 58 of the iron when iron 11 is placed on the base. A rectangular slot 26 and a generally circular opening 28 are formed in platform 15 to enable base 14 to be placed on a mounting bracket for enabling iron assembly 10 to be stored on a wall or similar surface when iron 11 is not in use.
Base 14 further includes a pivotal latch 22 having a hook-like portion 27 at one end and an elongated finger 25 extending from hook-like portion 27. The latch is preferably L or reverse J shaped. A handle 23 is connected to latch 22 to pivot the latch between locking and unlocking positions. As shown in FIGS. 2 and 3, latch 22 further includes a spring 24 which keeps the latch in its iron engaged position when the iron is placed on base 14. As illustrated in FIG. 3, a somewhat rectangular slot 29 is formed at the rear face of the iron between soleplate 54 and skirt 58. Hook-like portion 27 projects within slot 29 to retain iron 11 on base 14.
When the iron is not located on the base, for example when the iron is being used, finger 25 extends upwardly above the surface of platform 15. As iron 11 is moved towards the base, as shown in FIG. 2, finger 25 extends into the path of movement of the iron. When the iron is placed on the base, the rear portion of soleplate 54 contacts finger 25. The force developed by soleplate 54 engaging finger 25 rotates latch 22 counterclockwise into its locking position. When the user desires to remove iron 11 from base 14, the user rotates handle 23 clockwise to pivot latch 22 clockwise to release the iron. Even if engaging finger 25 is moved below the plane of platform 15 when the iron is not in the base, when the front of the iron is placed in the base so that projections 20 are inserted into groove 55, the rear face of skirt 58 will contact portion 27 and rotate the latch clockwise until finger 25 contacts soleplate 54 of iron 11. Further movement of the iron into the base will result in the latch pivoting counterclockwise into its locking position.
As shown in FIGS. 1 and 1A, base 14 includes a rear section 34 defining the rear wall of the base. Rear section 34 includes a vertically extending inwardly projecting abutment member 30 and a tail portion 32 extending upwardly from the top face 33 of rear section 34. Tail portion 32 comprises a generally horizontal extending floor member 35, a pair of inwardly inclined sidewalls 37 and an inwardly inclined front wall 39. The rear of tail section 32 is open.
Water cassette 16 includes a bottom wall 36 having a generally rectangularly shaped slot 43 formed therein. Slot 43 is configured to complement the shape of tail portion 32 so that the tail portion may be slid within the slot to join the cassette to the base. Slot 43 terminates in a vertical wall 45 which mates with vertical wall 39 of tail portion 32 when the tail portion is inserted into the slot. Cassette 16 further includes a plurality of horizontally extending ribs 38 to give rigidity to the wall 49 of cassette 16. The ribs also function as a cordwrap for power cord 59 when the iron is stored. A cap 51 is threadably received on the spout (not shown) of the cassette.
Housing 12 includes a nose portion 50. Housing 12 is attached to skirt 58 which, in turn, is attached to soleplate 54. Groove 55 is formed between the top surface of soleplate 54 and the bottom surface of skirt 58. Groove 55 enables the user to readily iron garments having buttons and also functions to receive projections 20 as previously described. Skirt 58 is generally L-shaped and comprises a horizontal leg 58A and a substantially vertical leg 58B.
Spray nozzle 52 extends forwardly of nose portion 50 of housing 12. Nose portion 50 further includes fill opening 48. Housing 12 further includes handle 40. Steam control valve 42 extends upwardly from handle 40. Handle 40 further includes spray pump control 44. Control 44 activates pump 44A (See FIG. 17).
An on/off switch 46 is positioned on the saddle portion 47 of housing 12. An arcuate opening 62 is formed in saddle portion 47. The arcuate opening forms a track for thermostat control knob 60. Arcuate opening 62 is inclined downwardly about 2° from its rear to its forward faces. The inclination of the track follows the general contour of saddle portion 47.
A rear cover 56 is attached to the outer surface of vertical leg 58B of skirt 58. An opening is formed between the outer surface of leg 58B and the opposed surface of cover 56. A cord bushing 57 extends outwardly through the opening. Cord bushing 57 surrounds power cord 59. Power cord 59 is connected to a source of electrical power for delivering electrical power to the iron for actuating among other components the electrical resistance heater (shown in FIG. 18) associated with the soleplate in heat transfer relation as is conventional in the art. A rotatable foot-like member 70 is attached to cover 56 for a reason to be more fully explained hereinafter.
Referring now in detail to FIGS. 4-9, the function of foot member 70 in conjunction with the steam control, on/off switch, and base shall be more fully explained.
As illustrated, foot member 70 is pivotally connected to cover 56 at pivot 72. As shown in FIG. 4, when the soleplate is placed in a horizontal plane and the iron is supported on an underlying garment on the surface of the ironing board, foot member 70 lies generally parallel to the soleplate and is spaced above the underlying support surface. An actuator arm 102 of steam control assembly 100 extends within the pivotal path of movement of foot member 70. When the iron is positioned as shown in FIG. 4, actuator arm 102 is urged towards cover 56.
Further as illustrated in FIG. 4, on/off switch 46 is in its on position connecting iron 11 to the source of electrical power. On/off switch 46 is pivotally connected to skirt 58 via bracket 76. On/off switch 46 includes a trigger member 78. Rotatable actuator 80 is positioned in the path of movement of foot member 70 when the iron is placed on base 14 as illustrated in FIG. 6. Movement of actuator 80 results in contact between the actuator and trigger member 78.
FIG. 5 illustrates the iron supported on its heel rest. The rear surface of cover 56 defines the heel rest for the iron. As the iron is rotated from its horizontal position to its heel rest position, the weight of the iron provides a force to rotate foot member 70 in a counterclockwise direction to achieve the position illustrated in FIG. 5. The weight of the iron also provides a force which causes the foot member to translate parallel to the soleplate in the direction of the arrow shown in FIG. 5. When so translated in the direction shown, notch 81 of the foot member engages a complementary surface 82 on the cover to latch the foot member in the position illustrated. Spring 83 is compressed as a consequence of the rotational movement of foot member 70.
When foot member 70 has been rotated to the position illustrated in FIG. 5, the foot member extends the effective length of the heel rest. It should be noted that iron 11 has a rather unique shape. Particularly, it should be noted that the upwardly extending leg 58B of skirt 58 is at an obtuse angle relative to horizontal leg 58A of the skirt. Typically, the upwardly extending leg of a skirt is perpendicular or at an acute angle to the horizontally extending leg of the skirt. Thus, the cover of the iron attached to the upwardly extending leg readily provides a suitable support for the iron when the iron is placed in the heel rest position. Due to the rather unique shape of the present iron 11, and in the absence of foot member 70, the weight of the iron will cause the iron to rotate in a counterclockwise direction if the iron were placed on cover 56. Foot member 70 when extended in the position shown in FIG. 5, increases the length of cover 56 so that the fulcrum or pivot point for the iron is shifted to the left (towards the soleplate) as viewed in FIG. 5 so that the clockwise moment arm tending to maintain the iron on its heel rest increases in magnitude and the counterclockwise moment arm decreases in magnitude. A relatively light weight 86 may be added to the handle to increase the magnitude of the clockwise moment arm to further insure the stability of the iron when the iron is placed on its heel rest. Since the fulcrum has been moved as a consequence of the extension of foot member 70, weight 86 may be relatively light so as not to unduly increase the total weight of the iron.
As illustrated in FIG. 5, the rotational movement of foot member 70 results in leg 70A thereof contacting actuator arm 102 of steam valve assembly 100. The force provided by leg 70A moving into contact with actuator arm 102 of steam valve 100 moves the actuator to the left as viewed in FIG. 4 or upwardly as viewed in FIG. 5. As shall be more fully explained hereinafter, this movement of the actuator arm results in the stoppage of flow of water from water reservoir 120 into steam chamber 122.
When iron 11 is moved from the heel rest position illustrated in FIG. 5 to the ironing position illustrated in FIG. 4, notch 81 disengages from surface 82, enabling foot member 70 to rotate in a clockwise direction as viewed in FIG. 4. Spring 83 provides the force to rotate foot member 70 from its heel rest position (FIG. 5) to the ironing position (FIG. 4). If the foot member is jammed into its heel rest position when the iron is returned to its ironing position, the lower edge 70D of foot member 70 extends below the bottom surface of soleplate 54. Edge 70D contacts the underlying support surface (ironing board or garment) and the force of such engagement triggers the foot member to translate in the direction opposite to the arrow illustrated in FIG. 5. This movement releases notch 81 from surface 82.
Referring now to FIG. 6, iron 11 is shown mounted on base 14. When the iron is placed on its base, abutment member 30 of rear section 34 of the base engages foot member 70 to rotate foot member 70 in a counterclockwise direction. As noted previously, the foot member is rotated in a counterclockwise direction when the iron is placed on its heel rest; however the shape of abutment member 30 causes the foot member to have a larger arc of rotation when the iron is placed on base 14 than when the iron is placed on its heel rest.
Foot member 70 is rotated counterclockwise when iron 11 is placed on the base, to move actuator arm 102 of steam valve assembly 100 to the left as shown in FIG. 6. Further, upper face 70C of the foot member engages actuator 80 associated with on/off switch 46. The actuator in turn engages trigger member 78 of the switch to rotate the switch in a counterclockwise direction from its on position to its off position. Thus, when iron 11 is placed on base 14, engagement of foot member 70 with abutment member 30 results in the foot member moving the actuator arm 102 to discontinue flow of water into steam chamber 122 and also results in the electrical power to the iron being interrupted since the on/off switch is moved into its off position. Inclined portion 41 of platform member 15 enables foot member to rotate to the position shown in FIG. 6 when the iron is placed on base 14. Inclined portion 41 accepts the extended portion of foot member 70 terminating in edge 70D.
Referring now to FIGS. 7, 8, 9, and 18, steam control assembly 100 shall now be described in detail. Steam control assembly 100 is mounted in a track 124 formed in the top surface 126 of skirt 58 and includes a longitudinally extending actuator arm 102 which, has one end as previously described extending into the path of travel of foot member 70. As shown in FIG. 9, actuator arm 102 is connected to a rib 106 which in turn is connected to an actuator fork 108 having a U-shaped slot 110 formed therein. One end 112 of a spring bellows 114 extends within slot 110.
The other end of spring bellows 114 terminates in a longitudinally extending pin 116. As shown in FIGS. 7 and 8, the pin and associated end of the spring bellows extend into an orifice 130 of conduit 132. Conduit 132 extends outwardly from the sidewall 134 of valve housing 136. Valve housing 136 includes a chamber 128. Passageway 140 communicates orifice 130 with chamber 128. Passageway 140 also communicates chamber 128 with outlet 142. Pin 116 extends through the passageway into the chamber to clean the passageway and meter the flow of water from the chamber into the passageway. End 112 of bellows 114 closes the passageway when the bellows is moved to the left as viewed in FIG. 8 and interrupts flow between chamber 128 and outlet 142. Actuator arm 102 moves bellows 114 to terminate the flow of water from water reservoir 120 into steam chamber 122.
Housing 14 includes steam control valve 42 for enabling the user to operate iron 11 in either dry or steam modes. FIG. 7 illustrates control valve 42 when the iron is being operated in its steam mode. Steam control valve 42 is connected via valve stem 144 to valve 146. As shown, when valve 146 is spaced above chamber 128, water will flow from water reservoir 120 into valve chamber 128 and thence into outlet 142 and steam chamber 122. When in the position shown, iron 11 may be used to steam and iron a garment. If dry ironing is desired, control valve 42 is moved downwardly to move valve stem 144 and attached valve 146 downwardly to close off the flow of water from reservoir 120 into chamber 122.
When the iron is rotated into its heel rest position, foot member 70 is rotated in a counterclockwise direction which, in turn, moves actuator arm 102 to the left as viewed in FIGS. 7 and 8. Movement of the actuator arm in this manner results in end 112 of bellows 114 closing the orifice to discontinue the flow of water from the water reservoir through chamber 128 and then into outlet 142. The same movement of the foot member and actuator arm occurs when the iron is placed in the base and the foot member engages abutment member 30.
Referring now to FIGS. 10-12, there is disclosed a preferred embodiment of the thermostat control for iron 11. As noted previously, saddle 47 of the iron includes an arcuate track 62 in which control knob 60 is movably mounted. Track 62 extends arcuately in a horizontal plane through the saddle portion and, as shown in FIG. 12 has a vertical slope so that track 62 is angled downwardly from the rear end of iron 11 towards nose portion 50 thereof. The slope of the track is substantially 2° and the arcuate travel of knob 60 in track 62 is substantially 10°.
As shown in FIG. 12, control knob 60 is connected to a vertically extending pin 150. The vertical axis of pin 150 is offset inwardly towards the center of iron 11 with respect to a vertical plane passing through the center of knob 60. Pin 150 extends within horizontally extending slot 152 of actuator lever 154. Lever 154 is integrally formed with rotatable actuator 156. Actuator 156 is attached to upwardly extending shaft 149 of thermostat 148. Thermostat 148 senses the temperature of soleplate 54. Pin 150 and actuator lever 154 comprise a linkage connecting control knob 60 to actuator 156, which in turn controls the operation of thermostat 148. The length of the radius establishing arcuate track 62 is substantially larger when compared to the length of the radius establishing the rotational path of movement of actuator 156. Movement of control knob 60 through a 10° arcuate path of travel results in substantially a 120° rotational movement of actuator 156 and shaft 149 of thermostat 148.
As shown in FIG. 11, as control knob 60 is arcuately moved along track 62, pin 150 transfers the force developed by movement of the knob to the actuator lever 154 and then to actuator 156 for establishing a set or operating point for thermostat 148. As the arcuate path for travel of knob 60 is substantially less than the arcuate path of travel of actuator 156, the distance between pin 150 and the center of rotation of actuator 156 is constantly changing. Further, the vertical position of the pin relative to slot 152 changes during movement of knob 60 due to the inclination of track 62. Pin 150 slides within slot 152 of lever 154 as a consequence of the movement of the control knob. In effect, the slot compensates for the vertical movement of pin 150 relative to lever 154 and also enables the distance between pin 150 and the center of rotation of actuator 156 to change. The described control enables thermostat control knob 60 to be mounted on a saddle having a rather complex geometrical shape.
Referring now to FIGS. 13-15, there is disclosed a preferred embodiment of the spray nozzle assembly 52 as used in the present iron assembly 10. Spray nozzle assembly 52 is mounted at the nose portion 50 of iron 11. Spray pump control 44 extends upwardly from handle 40 of iron 11. When the user desires to spray an underlying garment, the user presses downwardly on pump control 44 which creates a pumping action to pump water via pump 44A (See FIG. 17) from water reservoir 120 through line 182 and then through nozzle 52A of nozzle assembly 52. Nozzle assembly 52 includes nozzle 52A having a generally frusto-conically shaped outer wall 162 and an end wall 164 having a spray opening 166 generally located at the center thereof. Outer wall 162 defines a longitudinally extending bore 168. A spreader element 170 is disposed within the bore for reciprocating movement therein. Spreader element 170 includes a generally enlarged cylindrical head 172, a longitudinally extending body portion 174 and a spherical spreader end 176. A coupling 178 extends within an open end 180 of nozzle assembly 52. Line 182 is fitted over the outer end of coupling 178 to communicate bore 184 with water reservoir 120. Coupling 178 includes a valve seat 188 facing towards spherical end 176 of spreader element 170.
In operation, when the user desires to spray a garment being ironed, the user pumps control 44 to pump water from water reservoir 120 via pump 44A through line 182, thence into bore 168. The force of the water moves the spreader to the left as viewed in FIG. 14 so that surface 190 of the spreader contacts the inwardly extending pads 192 of nozzle assembly 52. Cylindrical head 172 of spreader element 170 directs the water in bore 168 towards the perimeter. Raised pads 192 comprise a plurality of circumferentially spaced members disposed on the interior surface of end wall 164. The water forced to the perimeter of bore 168 flows under the spreader and then radially inwardly between the raised pads to the centrally located orifice 166. The water is then sprayed in a desired pattern onto the garment.
When the user ceases pumping control 44, the return action of pump 44A creates a suction on line 182 moving spreader element 170 to the right as shown in FIG. 14 which results in spherical end 176 engaging seat 188 to create a seal. The seal prevents air from being sucked into the discharge side of pump 44A.
Referring now to FIGS. 16 and 17, the details of the fill system for water reservoir 120 shall be described in detail. A somewhat elliptically shaped opening 48 is formed in housing 12 at the nose portion or front end thereof 50. Opening 48 communicates with a water flow passage 194 defined between downwardly extending ribs 196. Ball valve or float valve 198 is disposed within flow passage 194. The specific gravity of ball valve 198 is less than one so that the valve floats on water. Lower wall 208 of reservoir 120 and the ribs entrap the ball valve. When the ball valve is moved upwardly within the passage, the ball valve seats against valve seat 202 to prevent water from splashing outwardly through opening 48.
When the user is filling water reservoir 120, a source of water is placed in communication with flow opening 48. For example, flow opening 48 may be placed beneath a faucet or cassette 16 may be used to add water to reservoir 120. Water fills the water reservoir causing float valve 198 to move upwardly in passage 194. When the iron is in normal use and water is in the reservoir, the float valve again is moved upwardly since its specific gravity is less than one. Valve 198 is forced against seat 202 to prevent the water from splashing outwardly through opening 48 during normal ironing use.
Further, when the iron is placed in a vertical position, for example when it is desired to steam or iron a garment held in a vertical position, if water level in the reservoir is relatively high, the water will cause ball valve 198 to remain seated, preventing water from splashing out when the iron is held upright.
Referring now to FIGS. 18 and 19, the structure of reservoir 120 shall now be more fully described. Reservoir 120 includes a plurality of walls 204 and 206 which extend upwardly part way from the top of lower or bottom wall 208 of reservoir 120. Walls 204 and 206 serve as dam means or as weir means to separate the reservoir into a forward compartment 210 and a rear compartment 211. It should be noted opening 212 in bottom wall 208 is located at the rear of forward compartment 210. In effect, walls 204 and 206 serve as dam means to provide a head of water above opening 212 when the iron is held in a vertical position. The head of water in forward compartment 210 enables iron 11 to be used as a steamer while the iron is held in a vertical position. By trapping water in the forward compartment when the iron is turned vertical, water will continue to flow from reservoir 120, through opening 212, steam valve chamber 128 and then into steam chamber 122. The iron will generate steam for a period of time until the supply of trapped water in compartment 210 is exhausted.
To replenish the supply of water in forward compartment 210, the user need only tip the iron forward and water in rear compartment 211 will flow into the forward compartment. When the iron is returned to its vertical position, divider walls 204 and 206 will retain the water in the forward compartment.
A water window 214 is disposed on saddle portion 47 and in alignment with rear compartment 211. When the iron is placed on its heel rest or held vertical, the user may look at the water window which, since it is in vertical alignment with the rear compartment provides an accurate indicator of the amount of water remaining in the water reservoir. If there is insufficient water in the reservoir to satisfy the steaming function, additional water can be added to reservoir 120 from cassette 16 or from a sink faucet.
While a preferred embodiment of the present invention has been described and illustrated, the invention should not be limited thereto but may be otherwise embodied within the scope of the following claims.
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An electric iron includes an electrically heated soleplate and a housing including a handle portion and a saddle portion. A thermostat is mounted on the soleplate for sensing the temperature thereof. An actuator is rotatably connected to the thermostat for establishing an operating temperature for the soleplate. A track is formed in the saddle portion of the housing. The track extends arcuately in a horizontal plane through the skirt and has a vertical slope. A control member is movably retained within the track. A linkage interconnects the control member to the actuator for converting the combined arcuate and vertical movement of the control member to rotational movement of the actuator.
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The Government of the United States of America has rights in this invention pursuant to Contract No. DE-AC02-76ET20131 awarded by the U.S. Department of Energy.
This is a division of application Ser. No. 062,109, filed July 30, 1979 now U.S. Pat. No. 4,241,150.
BACKGROUND OF THE INVENTION
The invention is concerned with electrode assemblies and use of same in electrical energy storage devices (EESD), especially a rechargeable EESD.
An EESD has utility in electric vehicle markets or in stationary power systems. Both of these markets may have a requirement to electrodeposit the reducible metal in a smooth dense manner and to remove it uniformly during discharge. In the electric vehicle market, there may be multiple shallow depth discharges occurring prior to a complete discharge. During discharge, difficulty has arisen when an oxidant is passed through a porous electrode. It may be significantly more electrochemically active than the counter electrode due to its high surface area. Due to the increase in current density, the metal of the counter electrode is removed quickly during discharge. Additionally, chemical corrosion of the reducible metal of the EESD by the presence of the oxidant in the electrolyte has a tendency to decrease the effectiveness of any EESD. These problems are collectively referred to as the edge activity of an oxidant electrode. The control of the edge effects of a porous oxidant electrode is the object of the present invention.
SUMMARY OF INVENTION
The invention is concerned with an electrode assembly comprising;
a. a porous electrode having a first and second exterior face with a cavity formed in the interior between said exterior faces thereby having first and second interior faces positioned opposite the first and second exterior faces;
b. a counter electrode positioned facing each of the first and second exterior faces of the porous electrode;
c. means for passing an oxidant through said porous electrode; and
d. screening means for blocking the interior face of the porous electrode a greater amount than the respective exterior face of the porous electrode, thereby maintaining a differential of electrode surface between the interior face and the exterior face.
The invention is also concerned with a method of discharging an electrical energy storage device comprising the steps;
1. providing a first electrode comprised of an electrochemically reducible substance;
2. providing a porous electrode having a first and second exterior face with a cavity formed in the interior between said exterior faces, thereby having first and second interior faces positioned opposite the first and second exterior faces;
3. providing a current carrying electrolyte between said electrodes;
4. passing an oxidant through said porous electrode;
5. screening the electrochemical activity of the porous electrode by blocking the interior face a greater amount than the respective exterior face of the porous electrode, thereby maintaining a differential of electrode surface between the interior face and the exterior face; and
6. closing the circuit between the first electrode and the porous electrode, thereby oxidizing the substance at the first electrode and reducing the oxidant at the porous electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of the process of the present invention;
FIG. 2 is a sectional view of a submodule of assembled electrolytic cells;
FIG. 3 is a case for supporting a submodule stack of electrolytic cells useful in the process of the present invention;
FIG. 4 is a sectional view substantially along lines 4--4 of FIG. 2;
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 4;
FIG. 6 is an exploded view of the electrodes useful in the process of the present invention;
FIG. 7 is a sectional view of the cell distribution manifold useful in the process of the present invention.
FIG. 8 is a side sectional view of a portion of the electrode assembly of the present invention showing the internal/external masking or screening effect.
DETAILED DESCRIPTION OF THE INVENTION
When porous electrodes are used in an EESD, their electrochemical activity must be taken into consideration during the discharge reaction because the oxidant will be reduced not only at the exterior electrode surface (generally longitudinal face) of the electrode, but also in the interior portion of the porous electrode.
In the most preferred manner the electrochemical reactions of discharge are:
Zn(metal)→Zn.sup.++ +2e
Cl.sub.2 →2Cl.sup.- -2e
Zn (metal)+Cl.sub.2 →Zn.sup.++ +2Cl.sup.-
It has been found, therefore, to control the edge effects of the porous electrode there should be a means for decreasing or screening or masking the electrochemical activity or the porous electrode by having a differential of a mechanical mask on the front or exterior portion of the electrode (exterior face) versus the interior face or internal mask of the electrode.
The positive electrodes of the present invention are primarily porous electrodes and may be carbonaceous electrodes, that is, comprised of carbon, activated carbon, graphite, activated graphite and mixtures thereof with or without other fillers that may be present in the carbonaceous electrode. The porous electrode may also be comprised of a film forming metal, such as titanium, titanium alloys, tantalum, tantalum alloys, zirconium, zirconium alloys, niobium, niobium alloys, tungsten, tungsten alloys and mixtures thereof. Any of the electrodes may be further comprised of catalytic materials well known in the art as noble metals as gold and silver and the like or Group VIII of the Periodic Table of Elements (HANDBOOK OF CHEMISTRY AND PHYSICS, 55th ed., 1974-1975, published by CRC Press) such as ruthenium, rhodium, palladium, osmium, nickel, iridium, platinum and the oxides thereof and mixtures thereof and the like. Generally, when the film forming metals are used, a catalyst is also used, e.g., ruthenized titanium.
The electrode assemblies may be useful in any EESD or any electrochemical reaction where a porous electrode is used, such as the utilization of hydrogen, oxygen, halogens, such as chlorine, bromine, iodine, fluorine, halodates, such as chlorates, bromates, the primary or secondary fuel cells, such as the metal hydride type, a metal halogen system and the like. Most preferred is the EESD of the metal halogen hydrate type such as the metal halogen device described in U.S. Pat No. 3,713,888 or No. 4,049,880, which are hereby incorporated by reference.
Operations of a zinc chloride battery system are described in Electric Power Research Institute (EPRI) EM-249 Report for Project 226-1 Interim Report, September 1976; EM-1051, Parts 1-4, Project 226-3 Interim Report, April 1979; Cost Analysis of 50 KWH Zinc-Chlorine Batteries for Mobile Applications, U.S. Dept. of Energy Report C00-2966-1, January 1978 and Safety and Environmental Aspects of Zinc-Chlorine Hydrate Batteries for Electric Applications, U.S. Dept. of Energy Report C00-2966-2, March 1978, herein incorporated by reference.
It has been found highly desirable that the electrode assemblies of the present invention are particularly useful in EESD where a current carrying electrolyte is employed such as an aqueous electrolyte. Any of the electrolytes well known in the art for the EESDs as described above may be employed. Electrolytes may be acidic or alkaline. The most preferred electrolyte is that useful in the metal halogen hydrate device described in the aforementioned patents, most preferably, a metal halogen device such as a zinc chlorine EESD.
It is preferred that when carbonaceous electrodes are employed in the electrode assembly in the present invention that the electrodes by activated in accordance with the case, Ser. No. 062,108 filed July 31, 1979, entitled ACTIVATING CARBONACEOUS ELECTRODES, filed concurrently herewith. The electrode assemblies are also preferably used as bipolar electrodes in accordance with U.S. Pat. No. 4,100,332, herein incorporated by reference.
Turning now to a discussion of the drawings, FIG. 1 is a schematic diagram of the electrode compartment of a preferred EESD such as the zinc chlorine chlorine hydrate system. In a container 10, sealed in place is an electrolyte reservoir 12 within a plastic reservoir 14. The electrolyte reservoir 12 functions as a sump from which electrolyte is pumped via line 16 by means of pump P into each of the stacks or submodules 18 via independent conduit 20. A valve V is placed in line 16 so that the electrolyte may be changed or dumped as desired. While the apparatus 10 is shown as containing a hood 22, it is to be appreciated that the design of such equipment may be modified to fit the desired characteristics of the electric vehicle or the standing power market. It is further to be appreciated that the electrolyte that is flowing from the sump 12 via line 16 into submodules 18 can be heated or cooled as is desired by auxillary apparatus (not shown).
FIG. 2 is a cross-section of the electrochemical apparatus of the present invention showing the electrolyte sump 12 being retained in a tray 22 and a series of electrical cells arranged in bipolar fashion having current terminals 19 and 21. The current is passed through the current terminals to conventional bus bars which in turn are connected to connector studs (not shown), thereby passing the current to each of the individual cells in each submodule. Each stack of electrodes is retained in a submodule tray 22, a sectional view of which is shown in FIG. 3. The submodule tray has an electrolyte drain cup 24 to which is attached a conduit 26 which in turn is connected to a passageway for movement of electrolyte away from the submodule to the sump via exit line 28. In order to prevent parasitic loses during the charging of the stack and to decrease the short circuiting that could possibly occur, the electrolyte passes down the conduit 26 through a pair of opposed serpentine like channels, best shown in FIG. 3 as channel 30 and 32 respectively with flow in the direction of the arrows.
The most preferred embodiment is that an electrolyte is flowing through and past the electrodes during the electrolytic reaction. To provide for the flowing electrolyte, an electrolyte distribution manifold 34 is provided for each submodule. The electrolyte flows from the sump 12 out exit port 36 and is pumped back to the submodule.
A sectional view showing a portion of a stack of electrodes with a porous carbonaceous electrode, which, in the most preferred embodiment, as the chlorine electrode of a zinc chlorine electrical energy storage device, is shown in FIG. 4. The submodule, which is a stack 18 of ten cells is inserted into the interior 35 of the submodule tray 22 wherein the electrolyte distribution manifold 34 would be joined with the submodule tray by positioning the manifold into channels 38.
The porous chlorine electrode 40 is arranged such that a pair of porous carbon plates 40a and 40b are joined together forming a cavity 41 to allow passage of electrolyte therethrough as shown by arrows 42. Gas venting holes (not shown) may be provided at the top of the porous chlorine electrode. The tops of three chlorine electrodes are shown in the right side of FIG. 4 while the remaining portion of FIG. 4 is a sectional view. To prevent distortion of the porous chlorine electrodes, stub 44 is present in the middle of the chlorine electrode to give strength thereto. The porous chlorine electrodes are manufactured to have an indented portion 46, in which the electrolyte feed tube 48 may be inserted. The electrolyte feed tube in turn in connected to the internal electrolyte distribution manifold at point 50. The electrolyte distribution manifold is comprised of a pair of complementary members 52 and 54 which are fastened together by nuts 56 and bolts 58.
A bipolar intermediate bus 60 is machined to receive the chlorine electrodes at points 62 and 64, while adjacent thereto is the metal or zinc electrode 68 which fits into the intermediate bipolar bus at point 70. To prevent short circuiting, to insure tight fit, to control discharge rates of chlorine electrode, and to control the edge effects thereof, spacers 72 and 74 join together the chlorine and zinc electrodes which are arranged in bipolar fashion. The masking or screening effect is performed by spacers 72 and 74.
In operation the electrolyte is flowed from the sump 12 through external manifold 80 into interior manifold 82 which is a conduit which is connected to the electrolyte distribution manifold at point 84. From the electrolyte distribution manifold, the electrolyte is passed through tubes 48 whereby the electrolyte exits from the tube at the bottom of the halogen electrode at point 83 and the electrolyte flows through the porous electrodes up the intercell spacing 84 into drain cup 24 down the exit conduit 26, into channels 30 and 32 as described above and out the exit 28 back to the sump.
The separation between the porous halogen electrode and the metal electrode ranges from about 40 to about 250 mils, preferably 80 mils (2 mm.)
The differential masking of the present invention is graphically shown in FIG. 8. The porous electrode is comprised of two elements 100a and 100b which are normally both comprised of a porous structure joined together at top (not shown) and bottom. FIG. 8 shows a "W" shaped element whereby the elements 100a and 100b fit within grooves 102a and 102b respectively formed from an inert plastic as Kynar (trademark of Penwalt Company for a fluoroplastic). The porous electrode of FIG. 8 is similar to the porous electrode of FIG. 4. Electrolyte distribution inlet 106 functions as electrolyte feed tube 48 of FIG. 6. For ease of distribution of electrolyte an inlet channel 108 is formed between members 110 and 112. The electrolyte flows from the sump 12 down distribution inlet 106 to near the base of the porous electrode, out channel 108 and fills cavity 114 and then passes through porous electrodes 100a and 100b, first through internal faces 120a and 120b respectively and out exterior faces 122a and 122b.
During operation (charge and discharge) of an EESD, the longitudinal faces 122a and 122b are blocked by an external mask 124a and 124b which physically covers the longitudinal (exterior) electrode face opposite the counter electrode 68. The internal mask 126 also physically blocks the interior faces of the porous electrode. A differential in physical screening or masking of the (external) longitudinal face versus the (internal) interior faces is maintained such that the height of the external mask (measured from the base of the porous electrode 128a or 128b to the top of external mask 130a or 130b, respectively) is much less than the height of the internal mask (measured from the base of the porous electrode 128a or 128b to the top of the internal mask 132). The differential between the interior screen or mask and the exterior mask ranges from about 0.05" (1.27 mm) to about 0.3" (7.62 mm), preferably 0.18" (4.57 mm).
Spacers 72 and 74 perform the same function on the sides of the electrodes shown in FIGS. 4 and 6 as the internal and external screen or mask at the base of the porous electrode of FIG. 8.
It is to be appreciated that the cells and submodule described herein can be combined in series or parallel relationship as is well known in the art.
Any means for storing and/or charging any oxidant can be used. The storage compartment 25 is connected to line 16 for operation during charging or during discharge of a primary or secondary (electrically rechargeable) EESD via line 23.
In the most preferred embodiment, chlorine formed during charging of a zinc chlorine battery with an aqueous zinc chloride electrolyte is converted to chlorine hydrate. The hydrate is then stored and is available for discharge by decomposing the chlorine hydrate to chlorine and water.
The halogen hydrate formation apparatus necessary for forming and storing the halogen hydrate during the charging and discharging of the electrical energy storage device is assembled to the remaining apparatus of FIG. 1. Any conventional equipment may be used such as that described in U.S. Pat. No. 3,713,888; No. 3,823,036; or Electric Power Research Institute and Department of Energy reports discussed supra.
Having described the invention in general, listed below are preferred embodiments where all temperatures are in degrees Centigrade and all parts are parts by weight unless otherwise indicated.
EXAMPLE 1
A Kynar (trademark of Pennwalt Company for a fluoroplastic material) electrode assembly was machined to the configuration of FIG. 8 incorporating various degrees of differential masking in order to evaluate their effectiveness in controlling the discharge edge activity in a zinc chlorine chlorine hydrate EESD. Th evaluation was performed in a test cell consisting of two pairs of mechanically framed chlorine electrodes (4 in.×2.65 in.×0.080 in.) and three zinc electrodes (4 in.×2.745 in×0.390 in.). The exposed apparent area for each chlorine electrode after framing (longitudinal face) is calculated to be 61.3 cm 2 (245.2 cm 2 per cell). The exposed apparent area for each zinc electrode is calculated to be 65.9 cm 2 per face. Two porous graphite electrodes (Union Carbide PG-60) were inserted into the Kynar frame. The cavity between the longitudinal (exterior) faces of the chlorine electrode is 0.08 in. The temperature of the electrolyte was controlled by circulating the electrolyte through a titanium coil immersed in a constant temperature water bath and held at a temperature of 30° C.±0.5° C. The volume of electrolyte used was approximately 800 milliliters. In the charge mode, chlorine gas produced electrochemically was vented from the sump. In the discharge mode, the required chlorine gas was fed to the sump via a gas dispersion tube from a chlorine gas cylinder.
Both the charge and discharge processes were operated under constant current. Cell voltage was measured using two voltage probes, separate from the current carrying terminal located at the top of the chlorine and zinc bus bars. The operating conditions are as follows:
TABLE I______________________________________Charge: 5 hrs at 27 mA/cm.sup.2 (i.e. 6.62 amp)Discharge: to 0 volt at 40 mA/cm.sup.2 (i.e. 9.8 amp)Chlorine ElectrodeArea 245.2 cm.sup.2Electrolyte: Before charge: 25% ZnCl.sub.2 (2.3M) pH: 0.18Flow rate: 2 ml/cm.sup.2 /minCl.sub.2 concentration: approximately 2 g/l______________________________________
The external shoulder (mask) size was held constant at 0.05 in. (mechanical masking on longitudinal face of the chlorine electrode) while the size of the internal shoulder (mask) was varied to obtain the various differential mask sizes (interior face). To determine the effectiveness of varying the internal and external mechanical screening or mask, the internal mask had an increase in size over the external mask of 0.05 in. (1.27 mm), 0.09 in. (2.29 mm), 0.20 in. (5.08 mm) and 0.45 in. (11.43 mm). All tests were conducted with the same electrodes under the same operating conditions. The effect of differential masking on the charge profile was negligible except to the extent that a good uniform smooth deposit of zinc was obtained. Most significantly were the losses in zinc area coverage at the various discharge steps as is shown below in Table 2.
TABLE 2______________________________________Effect of Differential Masking OnThe Area Loss of Zinc Coverage Area loss of Zinc Coverage (%)Mask (Inches) at Discharge Depth ofDifferential Internal External 50% 75% 90%______________________________________0.05 0.10 0.05 5 12 460.09 0.14 0.05 3 8.25 --0.20 0.25 0.05 3 4 13______________________________________
Observation of the zinc metal during various stages of discharge is quite signigicant. At 50% depth of discharge, a patch-type zinc plate had already developed. The size and shape of the zinc patch was similar for all differential mask sizes evaluated. At this stage of discharge, the top edge plate started baring of zinc, averaging 3% loss of zinc area.
At 75% of discharge, the size and shape change of the zinc deposits had become more significant. The decrease in area coverage of zinc was 12% for 0.05 in. differential mask, 8.25% for the 0.09 in. differential mask and 4% for the 0.20 in. differential mask. It is seen that the difference in shape between 50% and 75% depth of discharge was relatively small for 0.20 in. differential mask, but significantly large for 0.05 in. differential mask.
At 90% of discharge, a very well defined zinc patch had developed, the decrease in area coverage of zinc being 46% for 0.05 in. differential mask as compared to 13% for 0.20 in. differential mask. At this stage of discharge, the area coverage of zinc for 0.20 in. differential mask is still considered to be satisfactory.
In the case of the 0.45 in. differential mask, the graphite substrate at about 90% depth of discharge showed a reverse shaped patch. The center portion as bare of zinc implying an over-mask effect.
While applicant does not wish to be held to any theory, it is believed that with a porous electrode, i.e., a flow-through mode of operation, a portion of the chlorine electrode surface, behind the physical external mask, is participating in chlorine reduction resulting in localized increased current along the external mask edges which causes an increase in the rate of anodic dissolution at the edges of the zinc electrode. Increasing the size of the differential mask decreases the usable area behind the masks and compensates for the otherwise higher edge activity on discharge. This is reflected in all three of the experimental criteria selected for evaluating the differential masking approach to controlling edge activity on discharge. As can be seen from the above example, although the 0.45 in. differential mask size displayed a satisfactorily flat discharge profile, its average discharge voltage and coulombic efficiency were low. An over-mask effect was confirmed by visual inspection of the zinc deposit near the end of the discharge. The differential mask size of 0.20 in. was the most effective for retaining the shape of the zinc deposit near the end of the discharge and at the same time giving a satisfactory discharge profile.
It is to be appreciated that the physical mask can be manufacture in any practical means, such as injection molding the fluoroplastic Kynar or similar inert materials as polyvinyl chloride or polyester resins.
It is to be appreciated that FIG. 8 shows the masking to have been located at the base of the porous electrode. It should be appreciated that the physical masking may be on the side of the oxidant electrode as in FIG. 8 or at the top of the oxidant electrode, depending upon how one wishes to insert the oxidant into the porous electrode. Alternatively, the internal screening or mask may be on all sides of the porous oxidant electrode depending on the oxidant employed and the utilization of a flowing electrolyte. The masking may also take the form of a coating of an inert substance onto the interior and longitudinal (exterior) faces of the porous electrode.
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Described is an electrode assembly comprising;
a. a porous electrode having a first and second exterior face with a cavity formed in the interior between said exterior faces thereby having first and second interior faces positioned opposite the first and second exterior faces;
b. a counter electrode positioned facing each of the first and second exterior faces of the porous electrode;
c. means for passing an oxidant through said porous electrode; and
d. screening means for blocking the interior face of the porous electrode a greater amount than the blocking of the respective exterior face of the porous electrode, thereby maintaining a differential of oxidant electrode surface between the interior face and the exterior face.
The electrode assembly is useful in a metal, halogen, halogen hydrate electrical energy storage device.
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OBJECT OF THE INVENTION
This present invention refers to a loading wharf for industrial warehouses, of the type which has a folding ramp intended to make a bridge between the warehouse and the body or trailer to be loaded or unloaded, protective means for the closure of the space between the warehouse and the body or trailer of the lorry during the loading and unloading operations, an external door to close off the space when same is not in use and an internal door, preferably rapid, to keep the opening closed whilst the linking of the lorry trailer to the opening is carried out.
BACKGROUND TO THE INVENTION
At the present time it is common for industrial units to have one or more loading and unloading wharves for materials.
These wharves are arranged connecting to the threshold door of the access from the outside to the inside and include a ramp that makes the passage for the fork lift trucks or other vehicle loaders between the warehouse and the body or trailer of the lorry.
The ramp is generally arranged on the inside of a pit that goes into the space on the inside of the warehouse, the devices to activate the ramp being housed in said pit, mainly hydraulic cylinders, equipment to provide hydraulic pressure and control devices. This ramp is jointed on the lower part of the door or in a slightly emerging edge and which extends over the pit, which is more or less exposed.
These loading wharves also have some temporary protective means on the outside of the access door that are adaptable to the shape of the body of the lorry and which close the sides and top space that there is between the door of the wharf and the lorry.
The wharves of this type have some problems in use amongst which the one that stands out is the accumulation of dirt and waste in the pit, generated by the cleaning in the areas in which they are installed on entering into the space of same, allowing (due to the tolerances of the ramp with the floor for their possible movement) the passage of dust, insects and even rodents though these spaces.
In turn, the external protective means is shaped by some sheet rubber, canvas or similar elements, that are permanently exposed to the elements, on the external façade of the unit, being able to be damaged by the action of the wind or by vandalism if they are in poorly protected enclosures.
DESCRIPTION OF THE INVENTION
The loading wharf, object of this invention, presents some technical peculiarities that provide a series of advantages amongst which the following can be highlighted: Its installation is easier, occupying minimal space, without the need to carry out works for the construction of a pit, the availability of a flat and continuous floor on the inside of the warehouse, making cleaning and appropriate hygienic conditions easier, to provide a greater protection to the protective means when the loading wharf is not being used, to eliminate the problem of the build up of dirt in the ramp installation area, to enable the effective closure of the loading wharf when it is non-operational, with all of the operational elements contained on the inside and enabling the inter-connection of all of the openings to each other by means of the union of said structures via pipes through which the pre-installation of electrical, pneumatic and hydraulic supplies in addition to telephone and data lines can be made.
According to the invention the loading wharf includes a compact structure fixed into the entirety of the access opening to the warehouse and which marks out an intermediate space for the placement of the protective means and the folding ramp between the internal and external faces of the wall, with the possibility of movement between an operating position in which it projects from the stated intermediate space towards the outside to interact with the body or trailer of the lorry to be loaded or unloaded and in a non-operational position in which said means and ramp are positioned inside said intermediate space. Said compact structure includes a connection with the internal and external wall and some frames for the assembly of an external closure door on the outside of the warehouse, preferably of the rapid-opening type, that establishes the closure on the ground or floor level of the warehouse.
According to the invention, the intermediate space has: a lower area, located on the outside of the warehouse, for the housing of the platform behind the lorry or safety mechanisms intended to prevent the movement of the lorry during the loading and unloading operations; a lower intermediate area located below the inner level of the warehouse for the movement of the platform; an upper intermediate area, made flush with the inner level of the warehouse for the housing of the protective means and the ramp; and an upper area forming a housing for the gathering up of the outer and inner doors in the open position.
According to the invention the compact structure can be made into a single pre-assembled module, that takes in the total height of the access opening to the warehouse, from the outer lower level of the warehouse (running surface of the lorries) up to the end of the body of the upper area (above the lintel) if there is one or the lintel itself in the event of there not being a body, or in two independent modules; one lower module that includes the lower area and the lower intermediate area, this being, up to the internal level of the warehouse, and an upper module that includes the upper intermediate and the upper areas.
This second arrangement allows the lower and upper modules to be able to be supplied separately, so that they can be integrated in successive phases of the warehouse construction, avoiding unnecessary risks of deterioration of the upper module during the stated construction phases.
The protective means include two folding side pieces and an upper roof, the stated protective means and the levelling ramp being gathered up by some actioning devices that allow for the movement between the stated operational and non-operational positions. Said actioning means can be made up of motorised axles, hydraulic cylinders or any other, as they do not alter the essence of the invention.
In one embodiment of the invention, the inner and outer frames define some channelling for the controls of the doors themselves and for the passage of the electrical supply cables for the differing elements and auxiliary services, such as battery chargers for pallet trucks, signalling elements, light switches or means of communication. In this way the control or supply cables are prevented from being exposed and being able to be accidentally damaged during the loading and unloading operations.
In one embodiment of the invention, the sides of the protective means are assembled on both vertical turning axes, close to the inner sides of the compact structure, the upper roof on an upper horizontal turning axis and the ramp on a turning axis.
According to the invention, in the non-operational position both the sides and the roof of the protective means in the same way as the ramp are suitably arranged in a vertical manner on the inside of the intermediate opening set by the outer and inner doors and by the compact structure.
In one embodiment of the invention, there are some means of signalling on the opposing sides of the external frame to make the centring and approach of the vehicle to the wharf easier. These signalling devices include two sets of signals making horizontal and vertical signalling lights of differing colours on each side and which are easily visible using the rear view mirrors of the vehicle. When the lorry correctly approaches the loading wharf, the driver can see the signal lights in the two rear view mirrors and at the moment in which if the lorry deviates from an appropriate path towards one side the driver immediately sees a different number of signals on the left and right, warning in an unmistakable manner which side of the rear of the vehicle is wrong.
In one embodiment of the invention the vertical signal alignments are directed by some sensors that detect the position of the rear end of the lorry in regard to the loading wharf, said signals providing some visual information on the distance and correct position or of the excessive distance of the lorry from the loading wharf.
The ramp has the same width as that between the sides of the protective means in the operational position, with the exception of the support toe on the lorry, which has a narrower width, preventing the making of grooves or holes between same.
According to the invention in the operational position of the loading wharf the platform and protective means remain joined by some inter-connecting devices, acting as an adjustable unit for the variations in height of the body of the lorry brought about during the loading and unloading as a result of the weight variation borne by same; preventing rubbing between the lorry and the protective means during said loading and unloading operations.
The successive wharves can be inter-connected by means of built in tubes or pipes that can join the housings enabling the electrical, pneumatic, telephone and data installations to be made that are necessary for the inter-connection of all of the necessary components in the loading openings meaning that the inner walls remain clean, free of pipes and channelling that could affect or reduce the cleaning of same.
According to the invention, the inner floor of the warehouse is smooth and does not have any grooves or cuts that allow the accumulation of dirt and the communication areas between the inside and outside of the warehouse thus making the floor more hygienic and easier to clean.
In one variation of an embodiment of the invention, the external door of the wharf has an upper and a lower part that can fold on both horizontal axes said panels respectively making the roof of the protective means and an additional closure for under the level of the ramp.
In a second variation of an embodiment of the invention, the external door is made up from two side folding panels on both vertical axes, which additionally make the sides of the protective means and by an upper folding panel on a horizontal axis, which overlaps the side folding panels and in addition makes the roof of the protective means.
In a variation of the invention, the compact structure has a smaller width than the opening to the warehouse and has some lateral projections that easily cover the space existing between the opposing sides of the opening and the compact structure; thus enabling said compact structure to have side movement to make the joining up of the lorry to be loaded or unloaded easier.
According to the invention, the loading wharf on the lower part (running surface of the lorries) has a mechanism that is movable between a folded-up position in which there is a lower space on the inside set out by the compact structure and a projecting position; in its projecting position said mechanism has some means for the detection and blocking of the rear wheels of the lorry during the loading and unloading operations.
In addition and according to the invention in the upper area of the intermediate space the loading wharf has a connection for the supply of a lighting element for the loading and unloading on the inside of the lorry during the loading and unloading operations.
With these stated characteristics, the invention provides some significant technical advantages: The wharf can be supplied pre-installed as an integral module, sized in an appropriate manner for the access opening in which it is to be fitted, and without the need to carry out additional building works as now occurs in the case of the current pits; on closing the outer security door all of the components are hidden behind same, leaving the external façade completely clean; and preventing the build up of dirt and the entry of insects or rodents to the inside of the enclosure; it occupies a minimum space, on taking advantage of the lintel as that provided for the outer walls of the warehouse; it enables the interconnection of all the openings from one to another by means of the connecting of said structures via tubes or pipes through which the pre-installation can be carried out of the electrical, pneumatic and hydraulic supplies in addition to the telephone and data lines; and the problems of the build up of dirt in the area of the installation of the ramp is prevented.
The protective means, in whichever of its variations, has a space which can change its shape in the area of contact with the body of the lorry so as to enable the closure of same.
DESCRIPTION OF THE FIGURES
In order to complete the description that is being made and for the purpose of providing a better understanding of the characteristics of the invention, a set of drawings is attached to this present description in which the figures being by way of illustration and are not by way of limitation on the invention, in which the following is shown:
FIG. 1 shows a sectioned plan view of the wharf in a non-operational position.
FIG. 2 shows a profile view of the loading wharf in a non-operational position, with the internal and external doors in an open position and sectioned along a vertical plane.
FIG. 3 a shows a sectioned profile view of the loading wharf sectioned along a vertical plane and in an operational position.
FIG. 3 b shows an expanded detail of the previous figure in which a constructive form of the ramp can be seen, arranged in an operational position and supported on the body of the lorry.
FIG. 4 shows an elevation view of the loading wharf in a non-operational position with the external door closed and partially sectioned.
FIG. 5 shows a perspective view of the two loading wharves seen from the inside of the warehouse.-
FIG. 6 shows a front elevation view of a variation of an embodiment of the loading wharf in the closed position, in which the external door is made up of two foldable panels, an upper and a lower panel, which in the open position make the roof of the protective means and an additional closure placed in the lower area of the ramp.
FIG. 7 shows a lateral view of the door of FIG. 6 , sectioned along a vertical plane, in which the sides of the protective means of the external door have been represented with an unbroken line in the closed position and a dotted line in the open position.
FIG. 8 shows a front elevation view of a variation of an embodiment of the invention of the loading wharf in a closed position, in which the external door is made up from two foldable side panels making the sides of the protective means and an upper foldable cover making up the roof of the protective means.
FIG. 9 shows a side view of the door of FIG. 8 sectioned along a vertical plane and where the external door and the ramp in the closed position have been represented by an unbroken line and the unfolded position by a dotted line.
FIG. 10 shows an upper plan view of a variation of an embodiment of the loading wharf, sectioned along a horizontal plane, in which the compact structure has a smaller width than the warehouse opening, and has some lateral projections that fully cover the space that there is between the opposing sides of the opening and the compact structure; said compact structure thus being able to have lateral movement to make the coupling up of the lorry easier.
FIG. 11 shows a detail in perspective of the sides of the protective means in the operating position, making contact with the opposing sides of the ramp.
PREFERRED EMBODIMENT OF THE INVENTION
As and how can be seen in the referenced figures the loading wharf of the present invention includes a compact structure ( 1 ) fixed into the surrounding edge of the access opening of the warehouse and which marks out an intermediate space ( 2 ), between the inner and outer faces of the wall, for the placement of the sides and the roof of the protective means ( 4 , 5 ) and the foldable ramp ( 7 ).
In the operational position the protective means ( 4 , 5 ) and the levelling ramp ( 7 ) protrude from the intermediate space ( 2 ) towards the outside and, in the non-operational position they are arranged in an appreciably vertical manner on the inside of said intermediate space ( 2 ).
The compact structure ( 1 ) together with the external and internal faces of the wall includes some frames ( 1 a , 1 b ) for the assembly of an external closure door ( 3 a ) on the floor or external level of the warehouse, and an inner door ( 3 b ) preferably rapid opening that establishes the closure on the ground level or the inner floor level of the warehouse.
In the operational position of the closure the external door ( 3 a ) prevents access to the warehouse or inner enclosure and completely conceals the protective means and the ramp housed in the intermediate space ( 2 ) of the loading wharf.
This intermediate space ( 2 ) has: A lower area ( 21 ) located at ground level outside of the warehouse for the placement of the rear platform ( 61 ) of the lorry ( 6 ) so that it does not interfere with the wharf during the loading and unloading operations; a lower intermediate area ( 22 ) located below the level of the floor on the inside of the warehouse (between the lower area ( 21 ) and the inside floor level of the warehouse) for the movement of the platform and the housing of the actioning devices of same, represented in this case by a hydraulic cylinder ( 72 ) and the housing ( 9 ) where the hydraulic control and the electrical controls are located for the entirety of the system, likewise it is also used for the inter-connection between the differing openings that there may be; an upper intermediate area ( 23 ), flush with the inside floor level of the warehouse, for the housing of the sides and roof of the protective means ( 4 , 5 ) and the levelling ramp ( 7 ); and an upper area ( 24 ) making the housing for the take up of the external and internal doors ( 3 a , 3 b ) in the open position by means of some motorised drums.
The compact structure ( 1 ) can be made up of a single pre-assembled module and that is ready for installation or, as and how shown in FIG. 2 , by a lower module (Ml) that takes in the lower level ( 21 ) and a lower intermediate area ( 22 ), and by an upper module (M 2 ) that takes in the supper intermediate zones ( 23 ) and the upper area ( 24 ).
The successive wharves can be inter-connected by means of built in tubes or pipes ( 91 ), shown in FIG. 5 , that can join the housings ( 9 ) enabling the electrical, pneumatic, telephone and data installations to be made that are necessary for the inter-connection of all of the necessary components in the loading openings meaning that the inner walls remain clean, free of pipes and channelling that could affect or reduce the cleaning of same.
As can be seen in the figures attached, the external and internal frames ( 1 a , 1 b ) have some channelling for the controls of the doors themselves and the passage of the electrical supply cables and other accessorial services, such as battery chargers ( 13 ) shown in FIG. 5 , or others, from the control housings ( 9 ) fitted in the example shown in the intermediate area ( 22 ).
The sides of the protective means ( 4 ) are assembled onto both vertical turning axes ( 41 ), the roof of the protective means ( 5 ) on an upper turning horizontal axis ( 51 ) and the ramp ( 7 ) on a turning axis ( 71 ), which enables same to be appreciably flush with the internal floor level of the warehouse.
In the embodiment shown the upper frame ( 1 a ) comprises some means of signalling on the opposing sides so as to make the centring and approach of the vehicle ( 6 ) to the wharf easier, said signalling devices being represented, on each side, by two sets of signals ( 81 , 82 ) forming horizontal and vertical lines.
The horizontal signals ( 81 ) are visible with the rear view mirrors, showing the driver if the lorry is correctly centred in regard to the loading wharf whilst the luminous signs ( 82 ) of the vertical alignment, of differing colours, are controlled by some sensors integrated into the loading wharf and detect the correct position for the distance or the excessive closeness of the lorry to the loading wharf, the corresponding luminous signal ( 82 ) lighting up in a selective manner.
In the variation of the embodiment shown in FIGS. 6 and 7 the external door ( 3 a ) of the wharf includes an upper panel ( 31 ) and another lower panel ( 32 ) that are foldable on both horizontal axes, said panels making up the corresponding panels of the roof ( 5 ) of the protective means and an additional closure flush with the lower area of the ramp ( 7 ).
In the variation of the embodiment shown in FIGS. 8 and 9 , the external door ( 3 a ) is made up of two side panels ( 33 , 34 ) that are foldable on both vertical axes, that make the sides ( 4 ) of the protective means in the unfolded position, and by an upper cover ( 35 ) that is foldable on a horizontal axis, which makes the roof of the protective means ( 5 ) in the unfolded position.
In the example of the embodiment shown in FIG. 10 , the compact structure ( 1 ) has a smaller width than the warehouse access opening, and has some side projections ( 11 ) that fully cover the space existing between the opposing sides of the opening and the compact structure ( 1 ); thus said structure ( 1 ) is able to easily make the alignment and coupling with the lorry to be loaded or unloaded.
In the example of the embodiment shown in FIG. 3 a , the loading wharf has a mechanism ( 12 ) in the lower space ( 21 ) that is movable between the folded up position in which in the lower space ( 21 ) marked out by the compact structure, and a protruding position; said mechanism has some means for the detection and blocking of the rear wheels of the lorry ( 6 ) during the loading and unloading operations in its protruding position.
In the embodiment shown in said FIG. 3 a , on the upper area of the intermediate space ( 23 ) the loading wharf has a connection ( 10 ) for the supply of a lighting element for the loading and unloading area and for the inside of the lorry ( 6 ) during the loading and unloading operations.
As can be seen in FIG. 11 , in the operational position the sides of the protective means ( 4 ) make contact with the opposing sides of the ramp ( 7 ) preventing the existence of intermediate spaces and they are inter-connected with the ramp ( 7 ) actioning the protective means and the ramp as one unit that is adjusted in height to the support surface on the inside of the lorry, preventing rubbing between the body of the lorry and the sides ( 4 ) of the protective means.
Once having sufficiently described the nature of the invention, likewise having given an example of a preferred embodiment it is placed on record that the materials, shape, size and arrangement of the elements described can be modified provided that they do not mean an alteration of the basic essentials of the invention that are claimed below.
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A loading wharf includes a compact structure secured to the perimeter of an access opening formed in a wall of a building. The compact structure defining between the inner and outer faces of the wall, an intermediate space for placement of protective members and a folding ramp both of which move between an operational position in which protective members and ramp project from the intermediate space towards the outside, in order to interact with the body or trailer of the vehicle to be loaded or unloaded, and a non-operational position in which the protective members and ramp are positioned inside the intermediate space and are oriented vertically. The compact structure includes, corresponding to the outer and inner faces of the wall, frames for the mounting of an exterior closure door and of an interior door.
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BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a method for manufacturing a semiconductor device, especially a method for forming sidewall insulating films with different thicknesses on the same semiconductor substrate and a method for manufacturing a semiconductor device comprising a plurality of transistors having sidewall insulating films with different thicknesses.
[0002] In recent years, semiconductor devices in which an n-channel metal oxide semiconductor (MOS) transistor and a p-channel metal oxide semiconductor (MOS) transistor are formed on the same semiconductor substrate have been widely used. However, the diffusion coefficient of boron ion (B + ) used for forming a p-type diffusion layer is generally larger than that of arsenic ion (As + ) used for forming a n-type diffusion layer. Therefore, if a sidewall insulating film of a gate electrode of a n-channel MOS transistor and that of a gate electrode of a p-channel MOS transistor are formed of the same thickness, B + in the p-type diffusion layer diffuses into a channel region formed directly below a gate electrode. This is because the diffusion layer is formed in a self-alignment process. Thus distance between channel regions is decreased, and this causes the short channel effect and further causes a problem in which the required transistor properties cannot be obtained.
[0003] In the present invention, thickness of a sidewall insulating film means thickness of an insulating film comprising a sidewall, and this corresponds to the length of the sidewall in the horizontal direction (i.e., width of the sidewall). The length of a lightly doped drain (LDD) region in the horizontal direction (i.e., width of the LDD region) is defined by the width of the sidewall. Also, “the horizontal direction” means the direction parallel to an interface between a semiconductor substrate and an insulating film.
[0004] To solve the above described problem, a technique to form a sidewall insulating film of a p-channel MOS transistor more thickly than a n-channel MOS transistor has been heretofore provided. In this technique, a n-type heavily-doped source/drain region and a p-type heavily-doped source/drain region are then formed in a self-alignment manner in an ion implantation process in which a gate electrode and a sidewall insulating film are used as masks. As a result, a wide lightly-doped region is formed directly below the thick sidewall insulating film of the p-channel MOS transistor, and the distance between the p-type heavily-doped source/drain region and the gate electrode can be formed longer than the distance between the n-type heavily-doped source/drain region and the gate electrode. Therefore, B + in the p-type diffusion layer can be prevented from diffusing into the channel region formed directly below the gate electrode.
[0005] Japanese Patent Application Publication JP-A-2000-349167 (especially paragraph numbers 0021-0023, and 0037, and FIGS. 6 and 13) discloses technology to form sidewall insulating films of different thicknesses without increasing the number of the manufacturing steps. Here, when an ozone tetraethoxysilane non-doped silicate glass (hereinafter called O 3 -TEOS-NSG) film is deposited on a n-type lightly-doped region (i.e., a n-type LDD region) and a p-type lightly-doped region (i.e., a p-type LDD region) with the chemical vapor deposition (CVD) method, the speed of depositing an O 3 -TEOS-NSG film on the n-type LDD region and that of depositing an O 3 -TEOS-NSG film on the p-type LDD region are different because different types of impurities are doped in those regions, respectively. In this conventional technology, the thin O 3 -TEOS-NSG film is formed on the n-type LDD region and the thick O 3 -TEOS-NSG film is formed on the p-type LDD region because the speed of depositing the 0 3 -TEOS-NSG film depends on the type of the substrate on which the film is deposited. After those O 3 -TEOS-NSG films are formed, anisotropic etching is conducted for the O 3 -TEOS-NSG films, and thus a thin sidewall insulating film of the n-channel MOS transistor and a thick sidewall insulating film of the p-channel MOS transistor are formed.
[0006] As described above, with the conventional method, the speed of depositing an O 3 -TEOS-NSG film depends on the type and the concentration of impurities doped into a substrate (i.e., a lightly-doped region). The ratio between the thicknesses of the sidewall insulating films depends on the ratio between the thicknesses of the O 3 -TEOS-NSG films. Also, the ratio between the thicknesses of the O 3 -TEOS-NSG films depends on the ratio between the speeds of depositing the O 3 -TEOS-NSG films. Furthermore, the ratio between the speeds of depositing the O 3 -TEOS-NSG films depends on the difference between the types and concentrations of impurities doped into the substrate (i.e., a lightly-doped region). Therefore, in the above described conventional method, it has been required to regulate the concentration of the impurities doped into a lightly-doped region (i.e., a LDD region) or to properly select the type of impurities doped in a lightly-doped region for the purpose of forming a sidewall insulating film of the desired thickness. However, the regulation of the concentration of impurities doped into a lightly-doped region or the selection of the type of impurities doped into a lightly-doped region to form a sidewall insulating film with the desired thickness has to be done within an allowance of the device design. Therefore, the scope of the above described conventional method has been actually limited
[0007] Furthermore, semiconductor devices in which a high voltage metal oxide semiconductor field effect transistor (a high voltage MOSFET) and a high speed metal oxide semiconductor field transistor (a high speed MOSFET) are formed on the same semiconductor substrate has also been widely used. In this type of the semiconductor device, a thick sidewall insulating film is required for the high voltage MOSFET, and a thin sidewall insulating film is required for the high speed MOSFET. If the conductivity types (i.e., p-type or n-type) of the channels of the MOSFETs with different properties are the same, it is impossible to make a difference between the speeds of depositing the O 3 -TEOS-NSG films with use of the difference in the types of impurities doped into a substrate (i.e., a lightly-doped region). Therefore, it has been difficult to apply the above described conventional method to a semiconductor device in which different types of MOSFETs with different properties are formed on the same semiconductor substrate while the conductivity types of channels of MOSFETs are the same.
[0008] In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved method for manufacturing a semiconductor device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to provide a method for forming O 3 -TEOS-NSG films with different thicknesses on different regions without depending on the types or concentrations of impurities doped into a lightly-doped region formed on a silicon substrate.
[0010] Furthermore, it is also an object of the present invention to provide a method for manufacturing a semiconductor device comprising O 3 -TEOS-NSG sidewall insulating films with different thicknesses on different regions without depending on the types or concentrations of impurities doped into a lightly-doped region formed on a silicon substrate.
[0011] The method for manufacturing a semiconductor device including sidewall insulating films with different thicknesses is comprised of the steps of: (a) selectively forming a first gate electrode structure and a second gate electrode structure on a first active region and a second active region of a silicon substrate, respectively, (b) forming a first silicon oxide film on said first active region and said second active region, (c) forming a first lightly-doped region and a second lightly-doped region in said first active region and said second active region, respectively, by ion-implanting impurities into said first active region and said second active region through said first silicon oxide film, (d) removing said first silicon oxide film formed on said first active region while leaving said first silicon oxide film formed on said second active region, (e) forming an insulating film on said first region of said silicon substrate and an insulating film on said first silicon oxide film formed on said second active region of said silicon substrate with a thermal decomposition CVD method in which ozone and tetraethoxysilane are used as materials, said insulating film formed on said first region of said silicon substrate being formed more thickly than said insulating film formed on said first silicon oxide film formed on said second active region of said silicon substrate, and (f) forming a first sidewall insulating film on a sidewall of said first gate electrode structure while forming a second sidewall insulating film on a sidewall of said second gate electrode structure, said first sidewall being formed more thickly than said second sidewall. Here, the gate electrode structure means a structure comprising a gate electrode and an insulating film.
[0012] According to the present invention, an O 3 -TEOS-NSG film is formed both on a first region comprised of silicon and on a second region comprised of silicon oxide with a thermal decomposition CVD method in which O 3 and TEOS are used as materials. In this case, it is possible to regulate the ratio of the speed of forming the insulating film to be formed on the second region comprised of silicon oxide with respect to the speed of forming the insulating film to be formed on the first region comprised of silicon, by regulating only the flow rate of O 3 with respect to TEOS. Selecting silicon and silicon oxide as the substrate regions makes it possible to widely regulate difference between the thickness of the O 3 -TEOS-NSG film formed on the first active region and that of the O 3 -TEOS-NSG film formed on the second active region by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the types and concentrations of impurities doped into a first lightly-doped region in the first active region and impurities doped into a second lightly-doped region in the second active region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring now to the attached drawings which form a part of this original disclosure:
[0014] FIGS. 1A to 1 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with a first embodiment of the present invention.
[0015] FIGS. 2A to 2 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the first embodiment of the present invention.
[0016] FIGS. 3A to 3 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the first embodiment of the present invention.
[0017] FIGS. 4A to 4 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the first embodiment of the present invention.
[0018] FIG. 5 is partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the first embodiment of the present invention.
[0019] FIG. 6 is a chart showing the relationship between the flow rate of O 3 with respect to TEOS and the speed ratio of forming an O 3 -TEOS-NSG film on silicon with respect to forming an O 3 -TEOS-NSG film on silicon dioxide in the thermal decomposition CVD.
[0020] FIGS. 7A to 7 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with a second embodiment of the present invention.
[0021] FIGS. 8A to 8 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the second embodiment of the present invention.
[0022] FIGS. 9A to 9 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the second embodiment of the present invention.
[0023] FIGS. 10A to 10 C are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the second embodiment of the present invention.
[0024] FIG. 11 is partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the second embodiment of the present invention.
[0025] FIG. 12 is a chart showing the relationship between the flow rate of O 3 with respect to TEOS and the speed ratio of forming an O 3 -TEOS-NSG film on silicon in which H + is implanted with respect to forming an O 3 -TEOS-NSG film on silicon in which H + is not implanted in the thermal decomposition CVD.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Selected embodiments of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0027] Referring now to the drawings, preferred embodiments of the present invention will be described in detail.
FIRST EMBODIMENT
[0000] Method for Manufacturing a Semiconductor Device
[0028] FIGS. 1A to 1 C, 2 A to 2 C, 3 A to 3 C, 4 A to 4 C, and 5 are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the first embodiment of the present invention. According to the first embodiment, a high voltage MOSFET and a high speed MOSFET are formed on the same semiconductor substrate. A thick sidewall insulating film is required for the high voltage MOSFET, because the gate voltage of the high voltage MOSFET is high. On the other hand, a thin sidewall insulating film is required for the high speed MOSFET, because the gate voltage of the high speed MOSFET is low.
[0029] As shown in FIG. 1A , a field oxide film 2 is formed in element separation regions of a p-type silicon substrate 1 with the local oxidation of silicon (LOCOS) method. Thus a first active region 100 and a second active region 110 are defined by the field oxide film 2 . Here, the first active region 100 is a region on which the high voltage MOSFET is formed and the second active region 110 is a region on which a high speed MOSFET is formed.
[0030] As shown in FIG. 1B , a silicon dioxide film 12 of 365 Å in thickness is formed on the first active region 100 and on the second active region 110 of the p-type silicon substrate 1 .
[0031] As shown in FIG. 1C , a resist pattern 13 is formed on the silicon dioxide film 12 formed on the first active region 100 with a heretofore known lithography technique. After this, the silicon dioxide film 12 is etched using the resist pattern 13 as an etching mask. Thus, the silicon dioxide film 12 formed on the second active region 110 is selectively eliminated while the silicon dioxide film 12 formed on the first active region 100 is left.
[0032] As shown in FIG. 2A , the resist pattern 13 is eliminated, and then a silicon dioxide film is formed on the silicon dioxide film 12 formed on the first active region 100 and on the second active region 110 of the p-type silicon substrate 1 with a heretofore known method. As a result, a silicon dioxide film 14 of 400 Å in thickness is formed on the first active region 100 of the silicon substrate 1 , and a silicon dioxide film 15 of 75 Å in thickness is formed on the second active region 110 of the silicon substrate 1 .
[0033] As shown in FIG. 2B , a polysilicon film is formed on the silicon dioxide films 14 and 15 , and the field oxide film 2 , and impurities are ion-implanted into this polysilicon film. Then, the polysilicon film including the impurities and the silicon dioxide films 14 and 15 are patterned with a heretofore known lithography technique and etching technique. Thus, a first gate oxide film 3 - 1 and a first gate electrode 4 - 1 are formed on the first active region 100 , and a second gate oxide film 3 - 2 and a second gate electrode 4 - 2 are formed on the second active region 110 .
[0034] As shown in FIG. 2C , a silicon dioxide film 5 of 100-500 Å in thickness is formed with the thermal oxidation method or the CVD method, so that it covers the upper surface of the first active region 100 , the lateral surface of the first gate oxide film 3 - 1 , the upper and the lateral surfaces of the first gate electrode 4 - 1 , as well as the upper surface of the second active region 110 , the lateral surface of the second gate oxide film 3 - 2 , the upper and the lateral surfaces of the second gate electrode 4 - 2 .
[0035] As shown in FIG. 3A , the n-type impurity arsenic (As) is implanted into the silicon substrate 1 using the first gate electrode 4 - 1 , the second gate electrode 4 - 2 , and the field oxide film 2 as masks with an acceleration energy of 20 keV and the dose amount of 1.2×10 14 cm −2 . As a result, a first lightly-doped region 6 - 1 , which is self-aligned with respect to the first gate electrode 4 - 1 , is formed in the first active region 100 of the silicon substrate 1 . On the other hand, a second lightly-doped region 6 - 2 , which is self-aligned with respect to the second gate electrode 4 - 2 , is formed in the second active region 110 of the silicon substrate 1 .
[0036] Here, the thickness of the sufficiently thin silicon dioxide film 5 enables the accelerated ions to pass through the silicon dioxide film 5 and to be implanted into the silicon substrate 1 . Also, the silicon dioxide film 5 formed on the surface of the silicon substrate 1 prevents the surface of the silicon substrate 1 from being damaged by the ion implantation. Furthermore, the silicon dioxide film 5 prevents the surface of the silicon substrate 1 from being contaminated by metal.
[0037] Here, the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 are simultaneously formed by conducting the ion implantation once under the same conditions. However, the method of forming these regions is not limited to the above described method. For example, the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 may be separately formed in discrete ion implantation processes under different conditions.
[0038] As shown in FIG. 3B , a resist pattern 7 is formed on the silicon dioxide film 5 formed on the second active region 110 side with a heretofore known lithography technique.
[0039] As shown in FIG. 3C , the silicon dioxide film 5 is etched using the resist pattern 7 as an etching mask. Thus, the silicon dioxide film 5 formed on the first active region 100 side is selectively eliminated, and the silicon dioxide film 5 formed on the second active region 110 side is left. As a result, on the first active region 100 side, the upper surface of the first lightly-doped region 6 - 1 , the upper and lateral surfaces of the first gate electrode 4 - 1 , and the lateral surface of the first gate oxide film 3 - 1 are exposed.
[0040] As shown in FIG. 4A , the resist pattern 7 is eliminated and thus the upper surface of the silicon dioxide film 5 formed on the second active region 110 side is exposed. In other words, the second lightly-doped region 6 - 2 and the second gate electrode 4 - 2 formed on the second active region 110 side are covered with the silicon dioxide film 5 , while the first lightly-doped region 6 - 1 and the first gate electrode 4 - 1 formed on the first active region 100 side are exposed.
[0041] As shown in FIG. 4B , an O 3 -TEOS-NSG film 8 is deposited so that it covers the field oxide film 2 , the silicon dioxide film 5 formed on the second active region 110 side, the lightly-doped region 6 - 1 formed on the first active region 100 , the upper and lateral sides of the first electrode 4 - 1 formed on the first active region 100 , and the lateral sides of the first gate oxide film 3 - 1 with the thermal decomposition CVD method in which O 3 and TEOS are used as materials.
[0042] In forming the O 3 -TEOS-NSG film 8 , the thermal decomposition CVD method can be conducted under the desired conditions. However, as a typical example, the following conditions are set. That is, the flow rate of O 3 with respect to TEOS is set to be 7.5 and the pressure is set to be a normal pressure, and the temperature is set to be 400 degrees Celsius. The thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side is 5960 Å and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side is 4239 Å. In other words, when the flow rate of O 3 with respect to TEOS is set to be 7.5, the thickness of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side is 71.12% of that of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side. In depositing the O 3 -TEOS-NSG film 8 , the pressure may be typically set to be 400-760 Torr and the temperature may be typically set to be 400-450 degrees Celsius. The pressure and the temperature in depositing the O 3 -TEOS-NSG film 8 do not substantially influence the speed of forming the film. The speed of depositing the O 3 -TEOS-NSG film 8 on the first active region 100 side is faster than that of depositing the O 3 -TEOS-NSG film 8 on the silicon dioxide film 5 formed on the second active region 110 . Therefore, the thickness of the O 3 -TEOS-NSG film 8 deposited on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 deposited on the second active region 110 side are different. In other words, the O 3 -TEOS-NSG film 8 is thickly deposited on the first active region 100 side and is thinly deposited on the second active region 110 side.
[0043] FIG. 6 is a chart showing the relationship between the flow rate of O 3 with respect to TEOS and the ratio of the speed of forming the O 3 -TEOS-NSG film on the silicon dioxide with respect to the speed of forming the O 3 -TEOS-NSG film on silicon in the thermal decomposition CVD method. Here, the pressure and the temperature in forming the O 3 -TEOS-NSG film are set according to the above described conditions. The ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to the speed of forming the O 3 -TEOS-NSG film on silicon depends on the flow rate of O 3 with respect to TEOS. Specifically, the ratio of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to the speed of forming the O 3 -TEOS-NSG film on silicon is approximately in inverse proportion to the flow rate of O 3 with respect to TEOS. That is to say, if the flow rate of O 3 with respect to TEOS is increased, the difference between the speed of forming the O 3 -TEOS-NSG film on silicon and the speed of forming the O 3 -TEOS-NSG film on silicon dioxide is increased. As a result, the difference between thickness of the O 3 -TEOS-NSG film formed on silicon and that of the O 3 -TEOS-NSG film formed on silicon dioxide is increased.
[0044] Specifically, when the flow rate of O 3 with respect to TEOS is set to be 10, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to that of forming the O 3 -TEOS-NSG film on silicon is approximately 60%. Therefore, when the flow rate of O 3 with respect to TEOS is set to be 10, the difference between thickness of the O 3 -TEOS-NSG film formed on silicon dioxide and that of the O 3 -TEOS-NSG film formed on silicon is approximately 40%.
[0045] When the flow rate of O 3 with respect to TEOS is set to be 15, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to that of forming the O 3 -TEOS-NSG film on silicon is approximately 40%. That is to say, when the flow rate of O 3 with respect to TEOS is set to be 15, the thickness of the O 3 -TEOS-NSG film formed on silicon dioxide is decreased to only 40% of thickness of the O 3 -TEOS-NSG film formed on silicon. Thus, the difference between thickness of the O 3 -TEOS-NSG film formed on silicon dioxide and that of the O 3 -TEOS-NSG film formed on silicon is increased.
[0046] Furthermore, when the flow rate of O 3 with respect to TEOS is set to be 20, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to that of forming the O 3 -TEOS-NSG film on silicon is approximately 20%. That is to say, when the flow rate of O 3 with respect to TEOS is set to be 20, thickness of the O 3 -TEOS-NSG film formed on silicon dioxide is decreased to only 20% of thickness of the O 3 -TEOS-NSG film formed on silicon. Thus, the difference between thickness of the O 3 -TEOS-NSG film formed on silicon dioxide and that of the O 3 -TEOS-NSG film formed on silicon is increased.
[0047] Therefore, the following can be confirmed. That is, when the substrate region comprised of silicon is compared to the substrate region comprised of silicon dioxide, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to that of forming the O 3 -TEOS-NSG film on silicon significantly changes according to the change in the flow rate of O 3 with respect to TEOS.
[0048] Therefore, it is understood that the flow rate of O 3 with respect to TEOS may be set to be larger if the difference between thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side must be set to be larger. On the other hand, it is understood that the flow rate of O 3 with respect to TEOS may be set to be smaller if the difference between the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 must be set to be smaller. That is to say, the difference between the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side can be regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method. In other words, the O 3 -TEOS-NSG film 8 is formed on the first lightly-doped region 6 - 1 on the first active region 100 side and the O 3 -TEOS-NSG film 8 is formed on the silicon dioxide film 5 on the second active region 110 side, and thus difference between thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side can be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 .
[0049] As shown in FIG. 4C , the O 3 -TEOS-NSG film 8 is etched with a heretofore known anisotropic etching technique, and thus a first sidewall insulating film 9 - 1 is formed as the sidewall of the first gate electrode 4 - 1 and a second sidewall insulating film 9 - 2 is formed as the sidewall of the second gate electrode 4 - 2 . Here, a heretofore known anisotropic dry etching can be used as the anisotropic etching technique. The anisotropic etching for the O 3 -TEOS-NSG film 8 is conducted so that the top of the first gate electrode 4 - 1 corresponds to that of the first sidewall insulating film 9 - 1 . In other words, the anisotropic etching is conducted under conditions in which the O 3 -TEOS-NSG film 8 is etched on the basis of the top of the first gate electrode. The etching on the basis of the top of the first gate electrode 4 - 1 causes the O 3 -TEOS-NSG film 8 to be over-etched with respect to the top of the second gate electrode 4 - 2 . That is to say, the sidewall insulating film 9 - 1 and the second sidewall insulating film 9 - 2 depend on the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side. Therefore, the thickness of the first sidewall insulating film 9 - 1 is formed more thickly than that of the second sidewall insulating film 9 - 2 .
[0050] As shown in FIG. 5 , the n-type impurity As is implanted into the silicon substrate 1 using the first gate electrode 4 - 1 and the first sidewall insulating film 9 - 1 as the first mask, and using the second gate electrode 4 - 2 and the second sidewall insulating film 9 - 2 as the second mask with an acceleration energy of 50 keV and a dose amount of 6.0×10 15 cm −2 . Next, the thermal treatment of 950 degrees Celsius is conducted for 10 seconds and thus impurities are activated. As a result, a first heavily-doped source/drain region 10 - 1 , which is self-aligned with respect to the sidewall insulating films 9 - 1 , is formed in the first active region 100 of the silicon substrate 1 . On the other hand, a second heavily-doped source/drain region 10 - 2 , which is self-aligned with respect to the sidewall insulating films 9 - 2 , is formed in the second active region 110 of the silicon substrate 1 . As a result, a high voltage MOSFET is formed on the first active region 100 side and a high speed MOSFET is formed on the second active region 110 side.
[0051] Here, high gate voltage is applied to the first gate electrode 4 - 1 of the high voltage MOSFET, and low gate voltage is applied to the second gate electrode 4 - 2 of the high speed MOSFET. However, the first sidewall insulating film 9 - 1 is formed more thickly than the second sidewall insulating film 9 - 2 . Therefore, the distance between the first gate electrode 4 - 1 and the first heavily-doped source/drain region 10 - 1 is longer than the distance between the second gate electrode 4 - 2 and the second heavily-doped source/drain region 10 - 2 . In other words, a higher gate voltage can be applied to the high voltage MOSFET compared to the high speed MOSFET.
[0052] Here, the first heavily-doped source/drain region 10 - 1 and the second heavily-doped source/drain region 10 - 2 are simultaneously formed by conducting the ion implantation once under the same conditions. However, the method of forming these regions is not limited to the above described method. The first heavily-doped source/drain region 10 - 1 and the second heavily-doped source/drain region 10 - 2 may be separately formed in discrete ion implantation processes under different conditions.
[0053] According to the first embodiment of the present invention, a method of forming the O 3 -TEOS-NSG films 8 with different thicknesses on the first active region 100 side and the second active region 110 side is provided. The O 3 -TEOS-NSG film 8 is formed on the first lightly-doped region 6 - 1 (i.e., a silicon region) on the first active region 100 side. On the other hand, the O 3 -TEOS-NSG film 8 is formed on the silicon dioxide film 5 on the second active region 110 side. Therefore, O 3 -TEOS-NSG film 8 with different thicknesses are formed on the first active region 100 side and the second active region 110 side by using the difference between the speed of forming the O 3 -TEOS-NSG film 8 on a silicon dioxide region and that of forming the O 3 -TEOS-NSG film 8 on a silicon region. Selection of a silicon region and a silicon dioxide region as substrate regions enables the difference between thicknesses of the O 3 -TEOS-NSG film 8 formed on the first active region 100 and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 to be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 . Specifically, the ratio of the speed of forming the O 3 -TEOS-NSG film 8 on a silicon dioxide region with respect to that of forming the O 3 -TEOS-NSG film 8 on a silicon region can be regulated to be 80-40% by regulating the flow rate of O 3 with respect to TEOS to be 5-15. In other words, the ratio of the thickness of the O 3 -TEOS-NSG film 8 formed on a silicon dioxide region with respect to that of the O 3 -TEOS-NSG film 8 formed on a silicon region can be regulated to be 80-40% by regulating the flow rate of O 3 with respect to TEOS to be 5-15.
[0054] Furthermore, in the ion implantation process in which the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 are formed, the different substrates comprised of silicon and silicon dioxide respectively are provided by reusing a thin silicon dioxide film 5 that has been already used for the purpose of protecting the surface of the silicon substrate 1 . In other words, the ion implantation to form the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 is conducted by using the silicon dioxide film 5 as a passivation film. Then, the silicon dioxide film 5 formed on the first active region side is eliminated, while the silicon dioxide film 5 formed on the second active region 110 side is left. Thus, the substrate comprised of the first lightly-doped region 6 - 1 (i.e., silicon) can be formed on the first active region 100 side, and the substrate comprised of the silicon dioxide film 5 can be formed on the second active region 110 side. Therefore, a process of providing a substrate comprised of a silicon dioxide film used only for forming the O 3 -TEOS-NSG film 8 is not additionally required.
[0055] Furthermore, as described above, the selection of a silicon region and a silicon dioxide region as the substrate regions enables the difference between thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 to be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 . That is to say, a high degree of freedom can be assured for the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 , because the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 do not influence the difference in thicknesses of the O 3 -TEOS-NSG films 8 .
[0056] Furthermore, the O 3 -TEOS-NSG films 8 with different thicknesses are simultaneously formed in one forming process, and thus the number of manufacturing steps of a semiconductor device can be reduced. Because of this, further cost reduction can be realized. Also, in comparison with the case in which the O 3 -TEOS-NSG films 8 are formed in two separate forming processes, a margin is not required to be left in consideration of the spacing error of a mask in the first embodiment of the present invention. Therefore, an unnecessary increase in chip size can be avoided.
SECOND EMBODIMENT
[0000] Method for Manufacturing a Semiconductor Device
[0057] FIGS. 7A to 7 C, 8 A to 8 C, 9 A to 9 C, 10 A to 10 C, and 11 are partial vertical cross-section diagrams showing a method for manufacturing a semiconductor device in accordance with the second embodiment of the present invention. According to the second embodiment, a high voltage MOSFET and a high speed MOSFET are formed on the same semiconductor substrate. A thick sidewall insulating film is required for the high voltage MOSFET, because the gate voltage of the high voltage MOSFET is high. On the other hand, a thin sidewall insulating film is required for the high speed MOSFET, because the gate voltage of the high speed MOSFET is low.
[0058] As shown in FIG. 7A , a field oxide film 2 is formed in element separation regions of a p-type silicon substrate 1 with the local oxidation of silicon (LOCOS) method. Thus a first active region 100 and a second active region 110 are defined by the field oxide film 2 . Here, the first active region 100 is a region on which the high voltage MOSFET is formed and the second active region 110 is a region on which a high speed MOSFET is formed.
[0059] As shown in FIG. 7B , a silicon dioxide film 12 of 365 Å in thickness is formed on the first active region 100 and on the second active region 110 of the p-type silicon substrate 1 .
[0060] As shown in FIG. 7C , a resist pattern 13 is formed on the silicon dioxide film 12 formed on the first active region 100 with a heretofore known lithography technique. After this, the silicon dioxide film 12 is etched using the resist pattern 13 as an etching mask. Thus, the silicon dioxide film 12 formed on the second active region 110 is selectively eliminated while the silicon dioxide film 12 formed on the first active region 100 is left.
[0061] As shown in FIG. 8A , the resist pattern 13 is eliminated, and then a silicon dioxide film is formed on the silicon dioxide film 12 formed on the first active region 100 and on the second active region 110 of the p-type silicon substrate 1 with a heretofore known method. As a result, a silicon dioxide film 14 of 400 Å in thickness is formed on the first active region 100 of the silicon substrate 1 , and a silicon dioxide film 15 of 75 Å in thickness is formed on the second active region 110 of the silicon substrate 1 .
[0062] As shown in FIG. 8B , a polysilicon film is formed on the silicon dioxide films 14 and 15 , and the field oxide film 2 , and impurities are ion-implanted into this polysilicon film. Then, the polysilicon film including the impurities and the silicon dioxide films 14 and 15 are patterned with a heretofore known lithography technique and etching technique. Thus, a first gate oxide film 3 - 1 and a first gate electrode 4 - 1 are formed on the first active region 100 , and a second gate oxide film 3 - 2 and a second gate electrode 4 - 2 are formed on the second active region 110 .
[0063] As shown in FIG. 8C , a silicon dioxide film 5 of 100 Å-500 Å in thickness is formed with the thermal oxidation method or the CVD method, so that it covers the upper surface of the first active region 100 , the lateral surface of the first gate oxide film 3 - 1 , and the upper and the lateral surfaces of the first gate electrode 4 - 1 , as well as the upper surface of the second active region 110 , the lateral surface of the second gate oxide film 3 - 2 , and the upper and the lateral surfaces of the second gate electrode 4 - 2 .
[0064] As shown in FIG. 9A , the n-type impurity arsenic (As) is implanted into the silicon substrate 1 using the first gate electrode 4 - 1 , the second gate electrode 4 - 2 , and the field oxide film 2 as masks with an acceleration energy of 20 keV and the dose amount of 1.2×10 14 cm −2 . As a result, a first lightly-doped region 6 - 1 , which is self-aligned with respect to the first gate electrode 4 - 1 , is formed in the first active region 100 of the silicon substrate 1 . On the other hand, a second lightly-doped region 6 - 2 , which is self-aligned with respect to the second gate electrode 4 - 2 , is formed in the second active region 110 of the silicon substrate 1 .
[0065] Here, the thickness of the sufficiently thin silicon dioxide film 5 enables the accelerated ions to pass through the silicon dioxide film 5 and to be implanted into the silicon substrate 1 . Also, the silicon dioxide film 5 formed on the surface of the silicon substrate 1 prevents the surface of the silicon substrate 1 from being damaged by the ion implantation. Furthermore, the silicon dioxide film 5 prevents the surface of the silicon substrate 1 from being contaminated by metal.
[0066] Here, the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 are simultaneously formed by conducting the ion implantation once under the same condition. However, the method of forming these regions is not limited to the above described method. For example, the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 may be separately formed in discrete ion implantation processes under different conditions.
[0067] As shown in FIG. 9B , the silicon dioxide film 5 is eliminated with a heretofore known method.
[0068] As shown in FIG. 9C , a resist pattern 7 is formed so that it covers the upper surface of the second lightly-doped region 6 - 2 , on the upper and lateral surfaces of the second gate electrode 4 - 2 , the lateral surface of the second gate oxide film 3 - 2 , and surface of the field oxide film, which are all formed on the second active region 110 side.
[0069] As shown in FIG. 10A , hydrogen ion (H + ) is selectively ion-implanted into the first active region 110 using the resist pattern 7 as a mask. The ion implantation can be conducted with an acceleration energy of 10 keV and a dose amount of 1×10 13 -1×10 15 cm −2 .
[0070] As shown in FIG. 10B , non-doped silicate glass (NSG) film 8 (hereinafter called a O 3 -TEOS-NSG film) is deposited on the first active region 100 side into which H + is implanted and on the second active region 110 side into which H + is not implanted by the thermal decomposition CVD method in which ozone (O 3 ) and tetraethoxysilane (TEOS) are used as materials.
[0071] In forming the O 3 -TEOS-NSG film 8 , the thermal decomposition CVD method can be conducted under the desired conditions. However, as a typical example, the following conditions are set. That is, the flow rate of O 3 with respect to TEOS is set to be 10-20, and the pressure is set to be a normal pressure, and the temperature is set to be 400 degrees Celsius. The ratio of the thickness of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side is 80-60% of that of the O 3 -TEOS-NSG film 8 formed on the first active region 100 . In depositing the O 3 -TEOS-NSG film 8 , the pressure may be typically set to be 400-760 Torr and the temperature may be typically set to be 400-450 degrees Celsius. The pressure and the temperature in depositing the O 3 -TEOS-NSG film 8 do not substantially influence the speed of forming the film. The speed of depositing the O 3 -TEOS-NSG film 8 on the exposed surface of silicon into which H + is implanted is faster than that of depositing the O 3 -TEOS-NSG film 8 on the exposed surface of silicon into which H − is not implanted. Therefore, the thickness of the O 3 -TEOS-NSG film 8 deposited on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 deposited on the second active region 110 side are different. In other words, the O 3 -TEOS-NSG film 8 is thickly deposited on the first active region 100 side and it is thinly deposited on the second active region 110 side.
[0072] FIG. 12 is a chart showing the relationship between the flow rate of O 3 with respect to TEOS and the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted with respect to the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted in the thermal decomposition CVD method. Here, the pressure and the temperature in forming the O 3 -TEOS-NSG film are set according to the above described conditions. The ratio of the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted with respect to that of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted depends on the flow rate of O 3 with respect to TEOS. Specifically, the ratio of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted with respect to that of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted is approximately in inverse proportion to the flow rate of O 3 with respect to TEOS. That is to say, if the flow rate of O 3 with respect to TEOS is increased, the difference between the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted and that of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted is increased. As a result, the difference between thickness of the O 3 -TEOS-NSG film formed on silicon into which H + is implanted and that of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted is increased.
[0073] Specifically, when the flow rate of O 3 with respect to TEOS is set to be 10, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon dioxide with respect to that of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted is approximately 80%. That is to say, when the flow rate of O 3 with respect to TEOS is set to be 10, the difference between the thickness of the O 3 -TEOS-NSG film formed on silicon and that of the O 3 -TEOS-NSG film formed on silicon into which H + is not implanted is approximately 20%.
[0074] When the flow rate of O 3 with respect to TEOS is set to be 20, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted with respect to that of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted is approximately 60%. That is to say, when the flow rate of O 3 with respect to TEOS is set to be 20, the thickness of the O 3 -TEOS-NSG film formed on silicon into which H + is not implanted is decreased to only 60% of thickness of the O 3 -TEOS-NSG film formed on silicon into which H + is implanted. Thus, the difference between the thickness of the O 3 -TEOS-NSG film formed on silicon into which H + is not implanted and that of the O 3 -TEOS-NSG film formed on silicon into which H + is implanted is greatly increased.
[0075] When the substrate region comprised of silicon into which H + is implanted and the substrate region comprised of silicon into which H + is not implanted are used, the following can be confirmed. That is, the ratio of the speed of forming the O 3 -TEOS-NSG film on silicon into which H + is not implanted with respect to that of forming the O 3 -TEOS-NSG film on silicon into which H + is implanted significantly changes according to the change of the flow rate of O 3 with respect to TEOS.
[0076] Therefore, it is understood that the flow rate of O 3 with respect to TEOS may be set to be larger if the difference between thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side must be set to be larger. On the other hand, it is understood that the flow rate of O 3 with respect to TEOS may be set to be smaller if the difference between the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 must be set to be smaller. That is to say, the difference between the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side can be regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method. In other words, the O 3 -TEOS-NSG films 8 is formed on the first lightly-doped region 6 - 1 into which H + is implanted on the first active region 100 side and the O 3 -TEOS-NSG film 8 is formed on the second lightly-doped region 6 - 2 into which H + is not implanted on the second active region 110 side, and thus the difference between the thickness of the O 3 -TEOS-NSG films 8 formed on the first active region 100 and that of the O 3 -TEOS-NSG films 8 formed on the second active region 110 can be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 .
[0077] As shown in FIG. 10C , the O 3 -TEOS-NSG film 8 is etched with a heretofore known anisotropic etching technique, and thus a first sidewall insulating film 9 - 1 is formed as the sidewall of the first gate electrode 4 - 1 and a second sidewall insulating film 9 - 2 is formed as the sidewall of the second gate electrode 4 - 2 . Here, a heretofore known anisotropic dry etching can be used as the anisotropic etching technique. The anisotropic etching for the O 3 -TEOS-NSG film 8 is conducted so that the top of the first gate electrode 4 - 1 corresponds to that of the first sidewall insulating film 9 - 1 . In other words, the anisotropic etching is conducted under conditions in which the O 3 -TEOS-NSG film 8 is etched on the basis of the top of the first gate electrode 4 - 1 . The etching on the basis of the top of the first gate electrode 4 - 1 causes the O 3 -TEOS-NSG film 8 to be over-etched with respect to the top of the second gate electrode 4 - 2 . That is to say, the sidewall insulating film 9 - 1 and the second sidewall insulating film 9 - 2 depend on the thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side. Therefore, the thickness of the first sidewall insulating film 9 - 1 is formed more thickly than that of the second sidewall insulating film 9 - 2 .
[0078] As shown in FIG. 11 , the n-type impurity As is implanted into the silicon substrate 1 using the first gate electrode 4 - 1 and the first sidewall insulating film 9 - 1 as the first mask, and using the second gate electrode 4 - 2 and the second sidewall insulating film 9 - 2 as the second mask under with an acceleration energy of 50 keV and a dose amount of 6.0×10 15 cm −2 . Next, a thermal treatment of 950 degrees Celsius is conducted for 10 seconds and thus impurities are activated. As a result, a first heavily-doped source/drain region 10 - 1 , which is self-aligned with respect to the sidewall insulating films 9 - 1 , is formed in the first active region 100 of the silicon substrate 1 . On the other hand, a second heavily-doped source/drain region 10 - 2 , which is self-aligned with respect to the sidewall insulating films 9 - 2 , is formed in the second active region 110 of the silicon substrate 1 . As a result, a high voltage MOSFET is formed on the first active region 100 side and a high speed MOSFET is formed on the second active region 110 side.
[0079] Here, high gate voltage is applied to the first gate electrode 4 - 1 of the high voltage MOSFET, and low gate voltage is applied to the second gate electrode 4 - 2 of the high speed MOSFET. However, the first sidewall insulating film 9 - 1 is formed more thickly than the second sidewall insulating film 9 - 2 . Therefore, the distance between the first gate electrode 4 - 1 and the first heavily-doped source/drain region 10 - 1 is longer than distance between the second gate electrode 4 - 2 and the second heavily-doped source/drain region 10 - 2 . In other words, a higher gate voltage can be applied to the high voltage MOSFET compared to the high speed MOSFET.
[0080] Here, the first heavily-doped source/drain region 10 - 1 and the second heavily-doped source/drain region 10 - 2 are simultaneously formed by conducting the ion implantation once under the same conditions. However, the method of forming these regions is not limited to the above described method. The first heavily-doped source/drain region 10 - 1 and the second heavily-doped source/drain region 10 - 2 may be separately formed in discrete ion implantation processes under different conditions.
[0081] According to the second embodiment of the present invention, a method of forming the O 3 -TEOS-NSG films 8 with different thicknesses on the first active region 100 side and the second active region 110 side is provided. The O 3 -TEOS-NSG film 8 is formed on the first lightly-doped region 6 - 1 into which H + is implanted on the first active region 100 side. On the other hand, O 3 -TEOS-NSG film 8 is formed on the second lightly-doped region 6 - 2 into which H + is not implanted on the second active region 110 side. Therefore, the O 3 -TEOS-NSG film 8 with different thicknesses are formed on the first active region 100 side and the second active region 110 side by using the difference between the speed of forming the O 3 -TEOS-NSG film 8 on a silicon region into which H + is implanted and that of forming the O 3 -TEOS-NSG film 8 on a silicon region into which H + is not implanted. The selective implantation of H + enables the difference between thickness of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and that of the O 3 -TEOS-NSG film 8 formed on the second active region 110 side to be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 . Specifically, the ratio of the speed of forming the O 3 -TEOS-NSG film 8 on a silicon region into which H+ is not implanted with respect to that of forming the O 3 -TEOS-NSG film 8 on a silicon region into which H+ is implanted can be regulated to be 80-60% by regulating the flow rate of O 3 with respect to TEOS to be 10-20. In other words, the ratio of the thickness of the O 3 -TEOS-NSG film 8 formed on a silicon region into which H+ is not implanted with respect to that of the O 3 -TEOS-NSG film 8 formed on a silicon region into which H+ is implanted can be regulated to be 80-60 by regulating the flow rate of O 3 with respect to TEOS to be 10-20.
[0082] Furthermore, it is important to select the positive ion H + whose ion type is different from the impurities doped into the first lightly-doped region 6 - 1 and whose atomic mass is the smallest. The speed of forming the O 3 -TEOS-NSG film 8 formed on silicon is accelerated by implanting positive ions into the silicon. Here, the selection of H+ that has significantly smaller atomic mass compared to the impurity As doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 enables the first lightly-doped region 6 - 1 to be protected from damage and also enables the speed of forming the O 3 -TEOS-NSG film 8 to be increased.
[0083] Furthermore, as described above, selection of a silicon region into which H+ is implanted and a silicon region into which H+ is not implanted as the substrate regions enables difference of thicknesses of the O 3 -TEOS-NSG film 8 formed on the first active region 100 side and the second active region 110 side to be widely regulated by regulating only the flow rate of O 3 with respect to TEOS in the thermal decomposition CVD method, without depending on the type and concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 . That is to say, a high degree of freedom can be assured for the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 , because the type and the concentration of impurities doped into the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 do not substantially influence the difference in thicknesses of the O 3 -TEOS-NSG films 8 .
[0084] Furthermore, the O 3 -TEOS-NSG films 8 with different thicknesses are simultaneously formed in one forming process, and thus the number of manufacturing steps of a semiconductor device can be reduced. Because of this, further cost reduction can be realized. Also, compared to the case in which the O 3 -TEOS-NSG films 8 are formed in two separate forming processes, a margin is not required to be left in consideration of the spacing error of a mask in the second embodiment of the present invention. Therefore, an unnecessary increase in chip size can be avoided.
[0085] The above described H+ ion implantation process of may be conducted before the O 3 -TEOS-NSG film 8 is formed, and it also may be conducted before or after the first lightly-doped region 6 - 1 and the second lightly-doped region 6 - 2 are formed.
[0086] As described above, in the first and the second embodiments of the present invention, a n-channel high voltage MOSFET and a n-channel high speed MOSFET are formed on a p-type silicon substrate. However, the present invention can be applied to a situation in which a p-channel high voltage MOSFET and a p-channel high speed MOSFET are formed on a n-type silicon substrate. Also, the present invention can be applied to a situation in which a well region is formed on a silicon substrate and a high voltage MOSFET and a high speed MOSFET whose conductivity types are different with each other are formed on this well region.
[0087] This application claims priority to Japanese Patent Application No. 2005-067620. The entire disclosure of Japanese Patent Application No. 2005-067620 is hereby incorporated herein by reference.
[0088] The terms of degree, such as “sufficiently” and “substantially,” used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, the terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.
[0089] While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. Thus, the scope of the invention is not limited to the disclosed embodiments.
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A method for manufacturing a semiconductor device including sidewall insulating films with different thicknesses includes the steps of (a) selectively forming first and second gate electrode structures on first and second active regions of a silicon substrate respectively, (b) forming a first silicon oxide film on the first and second active regions, (c) forming first and second lightly-doped regions in the first and second active regions respectively, (d) removing the first silicon oxide film formed on the first active region while leaving the first silicon oxide film formed on the second active region, (e) forming an insulating film on the first region and an insulating film on the first silicon oxide film formed on the second active region, and (f) forming a first sidewall insulating film on a first gate electrode structure's sidewall while forming a second sidewall insulating film on a second gate electrode structure's sidewall.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2016-0002589, filed on Jan. 8, 2016, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a metamaterial-based electromagnetic wave polarization converter, and more particularly, to a metamaterial-based electromagnetic wave polarization converter in which a reception antenna and a transmission antenna are formed by using a metamaterial, to thus emit an incident non-polarized or polarized electromagnetic wave in an angle-converted polarization direction.
[0004] 2. Description of the Related Art
[0005] Many radio frequency antenna units mainly produce linearly polarized electromagnetic radiation. When a device such as a reception antenna is positioned to receive linearly polarized electromagnetic radiation, the directionality of the reception antenna associated with the transmitted electromagnetic radiation is important to receive a strong signal.
[0006] Most polarization converters used so far are in the form of waveguides or gratings. In recent papers, most polarization converters are configured to include helix structure, meta-surface and background plane composites, or bilayer symmetry pattern structures.
[0007] Recently, as research on metamaterials has progressed, areas of applications have been expanding. Metamaterials are materials that do not exist in the natural world, and are commonly called artificially designed materials whose electromagnetic characteristics are determined by a material structure.
[0008] The materials of nature are composed of atoms or molecules, but the metamaterials consists of an artificial meta-atom structure of a unit having a size smaller than wavelengths of electromagnetic waves incident from the outside. Recently, these metamaterials have attracted the attention of researchers worldwide in that they can artificially control the physical properties of materials for electromagnetic waves and light waves. One of the typical well-known properties among various metamaterials is a negative permeability characteristic, which can be applied to various fields such as negative refractive index, flat plate lens, and electromagnetic wave absorption.
[0009] It is believed that large efficiency can be obtained when metamaterials are applied to a device for converting polarized light of an electromagnetic wave in view of characteristics of the metamaterials. However, conventional metamaterial-based electromagnetic wave polarization converter that can readily use in market is need.
SUMMARY OF THE INVENTION
[0010] To solve the above problems, it is an object of the present invention to provide a metamaterial-based electromagnetic wave polarization converter that can efficiently emit a non-polarized or polarized electromagnetic wave in a polarization direction whose angle is converted into a desired angle.
[0011] According to an aspect of the present invention, there is provided a metamaterial-based electromagnetic wave polarization converter comprising: a reception antenna made of a metamaterial and allowing incident electromagnetic waves to resonate at a surface of the reception antenna to generate a surface current; a transmission antenna at a rear side of the reception antenna, and made of an angle-converted metamaterial to thus allow the electromagnetic waves transferred from the reception antenna to resonate to then be emitted in a polarization direction; and a connector made of a conductive material that connects the reception antenna and the transmission antenna, to thereby transfer a surface current generated from the reception antenna to the transmission antenna.
[0012] Preferably but not necessarily, the reception antenna includes a first panel member of a plane shape and a first slot formed on the first panel member and extending in one direction of the first panel member, the first slot being made of the metamaterial, and the transmission antenna includes a second panel member of a plane shape and a second slot formed on the second panel member and extending in a direction intersecting with the first slot of the first panel member, the second slot being made of the angle-converted metamaterial, in which the second slot is preferably extended to form a predetermined angle with respect to the first slot to correspond to a conversion angle of an electromagnetic wave to be converted.
[0013] Preferably, the connector includes a surface layer made of gold, and holes respectively corresponding to the connector are formed in the reception antenna and the transmission antenna, at connecting positions where the connector is connected to the reception antenna and the transmission antenna.
[0014] It is preferable that a filler material is filled between the reception antenna and the transmission antenna, and the filler material is a cycloolefin polymer.
[0015] It is preferable that a separation distance between the reception antenna and the transmission antenna is in a vicinity area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Exemplary embodiments of the inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:
[0017] FIG. 1 is a perspective view showing an embodiment of a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention;
[0018] FIG. 2 is an exploded perspective view of the metamaterial-based electromagnetic wave polarization converter of FIG. 1 ;
[0019] FIG. 3 is a front view of the metamaterial-based electromagnetic wave polarization converter of FIG. 1 ;
[0020] FIG. 4 is a side view of the metamaterial-based electromagnetic wave polarization converter of FIG. 1 ;
[0021] FIGS. 5 to 7 are graphs showing polarization conversion ratio measurement results according to a separation distance between a reception antenna and a transmission antenna in a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention;
[0022] FIG. 8 is a graph showing a conversion result according to a separation distance between a reception antenna and a transmission antenna in a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention;
[0023] FIG. 9 is a graph showing simulation results of polarization conversion in a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention; and
[0024] FIG. 10 is a graph for comparison of simulation results and actual measurement values of polarization conversion in a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] Hereinafter, a metamaterial-based electromagnetic wave polarization converter according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for similar elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention in order to clarify the present invention.
[0026] The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.
[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. In the present application, the terms “comprise”, “having”, and the like are used to specify that a feature, a number, a step, an operation, an element, a part, or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.
[0028] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and not be construed as ideal or overly formal in meaning unless expressly defined in the present application.
[0029] FIGS. 1 to 4 show a metamaterial-based electromagnetic wave polarization converter 10 according to an embodiment of the present invention.
[0030] Referring to FIG. 1 , the metamaterial-based electromagnetic wave polarization converter 10 includes a reception antenna 20 , a transmission antenna 30 , connectors 40 , and a filler material 50 that is filled between the reception antenna 20 and the transmission antenna 30 .
[0031] In this case, a metamaterial is made of a conductive material and has a shape of a periodic pattern with a size smaller than a wavelength of an incident electromagnetic wave. The metamaterial is a type of an antenna having a negative permeability, and can control the characteristic of the electromagnetic wave artificially.
[0032] The reception antenna 20 includes a first panel member 21 in the form of a square panel and a first slot 22 formed in the first panel member 21 .
[0033] The first slot 22 is formed so as to extend in a left-right direction at a center portion of the first panel member 21 , and is made of a metamaterial.
[0034] Two holes 23 are formed in the first panel member 21 , and the holes 23 are diagonally spaced at a left upper portion of the first panel member 21 and a right lower portion thereof when viewed from the front thereof.
[0035] The transmission antenna 30 is formed at a rear side of the reception antenna 20 .
[0036] The transmission antenna 30 includes a second panel member 31 corresponding to the first panel member 21 and a second slot 32 formed in the second panel member 31 .
[0037] The second slot 32 is also formed of a metamaterial, and the direction of the second slot 32 is a direction intersecting with the first slot 22 . That is, the first slot 22 extends along the left-right direction at the center portion of the first panel member 21 , while the second slot 32 extends vertically at the center portion of the second panel member 31 . Since the second slot 32 extends in a direction intersecting with the first slot 22 by a predetermined angle, an incident electromagnetic wave is transmitted in an angle-converted state by the transmission antenna 30 .
[0038] Two holes 33 are also formed in the second panel member 31 of the reception antenna 20 at the same positions as those formed in the first panel member 21 of the reception antenna 20 so as to be diagonally spaced from each other.
[0039] The connectors 40 connect the reception antenna 20 and the transmission antenna 30 to each other.
[0040] The connectors 40 are formed so that both ends of the first panel member 21 and the second panel member 31 are connected to each other at the portions where the holes 23 and 33 are formed. The connectors 40 are formed as tubular bodies of shapes and sizes corresponding to the holes 23 and 33 , in which a surface layer made of gold (Au) is formed on a surface of each of the connectors 40 .
[0041] Therefore, when electromagnetic waves are received at the reception antenna 20 , resonance occurs on the surface of the metamaterial of the first slot 22 , and thus a surface current is generated by resonance.
[0042] The generated surface current flows to the transmission antenna 30 along the surface layer of the connectors 40 and resonates at the surface of the metamaterial of the second slot 32 of the transmission antenna 30 .
[0043] FIG. 3 is a front view of the first panel member 21 . Referring to FIG. 3 , since the first panel member 21 is formed in the shape of a square panel, the width “a” and the length “b” are identical to each other, and both the width “a” and the length “b” are in this embodiment are 134 μm.
[0044] In this embodiment, a resonance frequency is 1 THz, and size of the first slot 22 varies in accordance with magnitude of the resonance frequency.
[0045] That is, the left-right length “c” and the width “d” of the first slot 22 are determined by equations
[0000]
λ
[
2
(
ɛ
sub
)
2
]
and
λ
[
20
(
ɛ
sub
)
2
]
,
[0000] respectively. When the resonance frequency is 1 THz as in the present embodiment, the left-right length “c” of the first slot 22 is 117 μm, and the width “d” of the first slot 22 is 15 μm. In this case, λ is a wavelength of an incident electromagnetic wave, and ε sub is a dielectric constant of a filler material located between the reception antenna and the transmission antenna. Hereinafter, the same symbols represent the same conceptual meanings.
[0046] The width “e” and the length “f” of each of the holes 23 can be obtained by the following equations
[0000]
λ
[
2
(
ɛ
sub
)
2
]
and
3
λ
[
4
(
ɛ
sub
)
2
]
,
[0000] respectively. In this embodiment, the width “e” and the length “f” of each of the holes 23 are formed in a square of 39 μm×39 μm.
[0047] The second panel member 31 is formed in the same size as the first panel member 21 and the former differs from the latter only in a point that the second slot 32 is formed to extend vertically.
[0048] As shown in FIG. 4 , a separation distance “g” between the reception antenna 20 and the transmission antenna 30 is 16 μm.
[0049] Since polarization conversion efficiency varies depending on the separation distance between the reception antenna 20 and the transmission antenna 30 , the separation distance between the reception antenna 20 and the transmission antenna 30 is important.
[0050] FIGS. 5 and 6 are graphs of experimental results for examining the conversion efficiency of the electromagnetic wave according to the separation distance between the reception antenna 20 and the transmission antenna 30 .
[0051] The proper separation distance between the reception antenna and the transmission antenna should be within a neighboring area 2L slot 2 /λ, and L slot is defined as λ/[2(ε sub ) 2 ]. When the separation distance “g” is 5 μm (2L slot 2 /λ), the polarization conversion efficiency sharply drops. When the separation distance is 80 μm (2L slot 2 /λ), the polarization conversion efficiency gradually decreases, in comparison with the 16 μm, but the Q-factor decreased and undesired peaks were observed in the inside of the converter due to fabry-perot resonance and the like.
[0052] As shown in FIG. 5 , only the cases where the separation distances are 5 μm, 16 μm, and 80 μm are separately extracted, the first curve (e.g. solid line) indicates the case where the separation distance between the reception antenna 20 and the transmission antenna 30 is 16 μm, the second curve (e.g. alternated long and short dash line) indicates the case where the separation distance is 5 μm, and the third curve (e.g. alternated long and two short dashes line) indicates the case where the separation distance is 80 μm. When the separation distance “g” is 5 μm, the polarization conversion efficiency sharply drops. When the separation distance is 80 μm, the polarization conversion efficiency gradually decreases, in comparison with the 16 μm, but the Q-factor decreased and undesired peaks were observed in the inside of the converter due to fabry-perot resonance and the like.
[0053] When the resonance frequency is 1 THz and the wavelength λ of the electromagnetic wave is 300 μm as in the present embodiment, the appropriate separation distance between the reception antenna 20 and the transmission antenna 30 is 5 μm to 80 μm.
[0054] Since the resonance frequency is 1 THz and the wavelength λ of the electromagnetic wave is 300 μm as shown in FIGS. 6 and 7 , the conversion efficiency graphs according to the separation distances between the reception antenna 20 and the transmission antenna 30 can be obtained. However, when the resonance frequency and the wavelength length vary, the appropriate separation distance between the reception antenna 20 and the transmission antenna 30 varies. When the separation distance is farther from the proper separation distance, the resonance frequency is shifted to a low frequency band. When the separation distance is closer to the proper separation distance, a noticeable frequency shift does not occur, but the polarization conversion efficiency is lowered due to the evanescent coupling of the reception antenna and the transmission antenna.
[0055] Therefore, the appropriate separation distance between the reception antenna 20 and the transmission antenna 30 can be expressed as 2L slot 2 /λ to 2L slot 2 /λ in which L slot is λ/[2(ε sub ) 2 ].
[0056] In addition, a filler material 50 is filled between the reception antenna 20 and the transmission antenna 30 .
[0057] The filler material 50 is preferably a material having a low dielectric constant.
[0058] FIG. 8 shows experimental data for measuring the conversion efficiency of the electromagnetic wave according to the type of the filler material 50 .
[0059] In the graph, the first curve (e.g. solid line) indicates the experimental value in the case of Zeonor which is a cycloolefin polymer as the filler material 50 , and the second curve (e.g. dotted line) indicates the experimental value in the case where gallium arsenide (GaAs) is used as the filler material 50 .
[0060] Zeonor is a material with a dielectric constant of 2.33 and gallium arsenide has a dielectric constant of 17.
[0061] As shown in the graph, it can be seen that the lower the dielectric constant, the better the conversion efficiency. It can be confirmed that Zeonor, a cycloolefin polymer having the lowest dielectric constant in the terahertz range, is the most preferable filler material 50 .
[0062] As a result of simulation of the polarization change efficiency of the electromagnetic wave by using the metamaterial-based electromagnetic wave polarization converter 10 according to the embodiments of the present invention, the graph shown in FIG. 9 was obtained.
[0063] From the simulation results, it can be seen that an E-field incident in the Y-axis direction is polarized in the X-axis direction after transmission. In this simulation, the resonance point was designed at 1 THz, and the transmittances in the X-axis and Y-axis directions are 0.88 and 0.01, respectively.
[0064] FIG. 10 is a graph for comparison of simulation results and actual measurement values of polarization conversion in a metamaterial-based electromagnetic wave polarization converter 10 according to an embodiment of the present invention.
[0065] The actual experiment proceeded with an instrument TPS-3000. Since the instrument TPS-3000 emits the E-field in the Y-axis direction and measures the E-field in the Y-axis direction, measurements were executed by using two polarization converters.
[0066] The transmittances of the simulation value and the measured value were 0.66 and 0.31, respectively, at 1 THz or so. The insertion loss of the polarization converter was multiplied by two. In one polarization converter, the transmittances of the simulation value and the measured value were expected as 0.81 and 0.56, respectively.
[0067] As a result of executing the polarization conversion experiment using the actual prototype of the metamaterial-based electromagnetic wave polarization converter, it is not the same as the simulation, but the polarization conversion efficiency of the electromagnetic wave is high in the 1 THz band as in the simulation.
[0068] The metamaterial-based electromagnetic wave polarization converter according to the present invention can emit an electromagnetic wave in an angle-converted polarization direction by using a metamaterial, and has an advantage of high conversion efficiency.
[0069] The description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features presented herein.
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Provided is a metamaterial-based polarization converter in which a reception antenna and a transmission antenna are formed by using a metamaterial, to thus emit an incident non-polarized or polarized electromagnetic wave in an angle-converted polarization direction. The metamaterial-based electromagnetic wave polarization converter includes: a reception antenna made of a metamaterial and allowing incident electromagnetic waves to resonate at a surface of the reception antenna to generate a surface current; a transmission antenna at a rear side of the reception antenna, and made of an angle-converted metamaterial to thus allow the electromagnetic waves transferred from the reception antenna to resonate to then be emitted in a polarization direction; and a connector made of a conductive material that connects the reception antenna and the transmission antenna, to thereby transfer a surface current generated from the reception antenna to the transmission antenna.
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FIELD OF THE INVENTION
The present invention relates generally to buildings and related structures, and more specifically to a system providing for the complete security and anchoring of all of the components of a completed family dwelling type structure or the like having a sloped roof, against high winds and related storm damage.
BACKGROUND OF THE INVENTION
In most areas of the nation, buildings and structures are subject to at least occasional high winds and severe storms. Hurricanes and tropical storms are relatively frequent occurrences with respect to the average life span of the typical building or dwelling, in the southeast and eastern parts of the country and occasionally hit the California coast and Hawaii as well. Tornados have been reported in every state in the union, including Alaska. Aside from such severe weather as mentioned above, severe thunderstorms can create localized gusts exceeding 100 miles per hour on occasion, and severe frontal systems can also cause extensive winds.
Accordingly, most areas of the country have developed building codes requiring minimum strength to provide at least some resistance to such severe conditions when they occur. While these requirements vary somewhat depending upon the specific area, they all are directed to new construction and do not address the need to anchor and secure a preexisting, completed structure. Of those devices and systems known, they primarily relate to means to anchor and retain temporary structures (e. g., mobile homes, sheds, haystacks and the like) and/or provide specialized components for use in the construction of new structures, which components are not readily adaptable for use in anchoring and securing portions of an already existing building.
The need arises for a system of anchoring and securing a preexisting, completed structure against high winds and storm conditions. The system must provide for the securing of shingles or like roof cover, securing the roof to the remaining structure, and securing the entire structure to the ground or foundation. Moreover, the system must be readily installable to the exterior of the structure without requiring any disassembly of the structure, and must be relatively inexpensive and easy to install.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 181,518 issued to Samuel M. Bollman on Aug. 29, 1876 discloses a Hay or Grain Cap comprising a multiple section, rigid pitched roof for temporary installation over a haystack or the like. Stakes tied to each corner may be driven into the ground to secure the device. No means of securing any shingles to the roof, securing the roof to an underlying building structure, or securing a building structure to its foundation is disclosed.
U.S. Pat. No. 194,455 issued to Robert Montgomery on Aug. 21, 1877 discloses Section-Roofs For Sheltering Grain Etc. The device is similar to the Bollman patent discussed above, but depends primarily on weights suspended along the eaves for security. Additional security is provided by a stake driven into the hay or grain, and tied to the roof. A support structure for the roof is also disclosed, but no means of securing the roof to the support structure is shown.
U.S. Pat. No. 822,143 issued to Alexander Mann on May 29, 1906 discloses a Stack Cover formed of a plurality of interlocked corrugated metal sheets, secured by a plurality of weights suspended from the eaves. No other securing means is disclosed.
U.S. Pat. No. 1,864,403 issued to Charles B. Bradley on Jun. 21, 1932 discloses a House Anchor comprising two oppositely spaced cables extending over the roof and through sleeves installed through the roof at each corner of the house. No intermediate tiedowns are shown, nor is any means disclosed for securing shingles on the roof. Moreover, no structural ties between the roof structure and the wall structure are provided.
U.S. Pat. No. 3,309,822 issued to William H. Dunkin on Mar. 21, 1967 discloses an Exterior Anchoring Apparatus For Surface Sheet. The apparatus comprises a series of cables and fasteners extending from the ridge of a gabled roof downward to each of the eaves, rather than laterally across one gable panel as in the present invention. No means is disclosed for securing shingles on a shingled roof, nor is any means disclosed for securing the roof structure to the remainder of the building.
U.S. Pat. No. 3,335,531 issued to Nardie F. Grimelli et al. on Aug. 15, 1967 discloses a Tie-Down For House Trailers Or The Like. The apparatus comprises a series of specialized brackets providing for the securing of a rope(s) or cable(s) across the flat roof of a mobile structure, and ground anchoring means. No similarity is seen to the present invention, as the apparatus is not readily adaptable to a fixed, permanently constructed and located structure having a sloped roof.
U.S. Pat. No. 3,449,874 issued to Jean L. Beaupre on Jun. 17, 1969 discloses a House Anchorage comprising a plurality of brackets secured to a house with cables tying the brackets to ground anchoring points. While some of the brackets are secured to the underside of the rafters at the eaves, the outward extension of the cables therefrom would result in significant obstruction of the walls of the house when working near such walls was required. Moreover, no shingle securing means or means of securing the upper wall structure to the roof structure is disclosed.
U.S. Pat. No. 3,949,527 issued to Paul B. Double et al. on Apr. 13, 1976 discloses a Material Supported Cover And Method For Securing Said Cover To The Ground. The patent is primarily directed to a specialized anchor plate which is installable in the ground. In the embodiment directed to securing a structure to the ground, no means of securing shingles or one portion of the structure to another of a permanently installed structure is disclosed; the only structure disclosed is a mobile home.
U.S. Pat. No. 4,257,570 issued to Carl M. Rasmussen on Mar. 24, 1981 discloses a Tie Down Assembly for use in securing a camper shell to a pickup truck or the like. No means of securing building structural components together or to ground anchors is disclosed.
U.S. Pat. No. 4,288,951 issued to Denny L. Carlson et al. on Sep. 15, 1981 discloses an Auxiliary Insulated Roof System for mobile homes, in which a bracket providing for the securing of the insulation to the upper wall structure is disclosed. No shingle securing means, means for securing rafters to the wall structure, or securing any of the structure to the ground or foundation is disclosed.
U.S. Pat. No. 4,587,789 issued to Garry Tomason on May 13, 1986 discloses an Anchoring Means For A Prefabricated Roof Or Siding Panel. The patent is directed to a means of securing specially formed, prefabricated roof or exterior panels from within, and does not lend itself to securing previously completed structures using standard construction methods and materials from the exterior after completion. Moreover, no means of securing the structure to a foundation or to the ground is disclosed.
U.S. Pat. No. 4,796,403 issued to David A. Fulton et al. on Jan. 10, 1989 discloses an Articulating Roofing Panel Clip for securing standing seam sheet panels together. The clip(s) cannot be installed over an existing, completed roof structure and do not lend themselves to installation on shingled roofs or to secure any other structural components to one another or to the ground.
Finally, U.S. Pat. No. 5,109,641 issued to Peter Halan on May 5, 1992 discloses Roof Transition Flashing for installation at the juncture of a sloped roof and vertical siding. The flashing fails to anchor any of the structure to any other part of the structure, and must be installed during construction.
None of the above noted patents, taken either singly or in combination, are seen to disclose the specific arrangement of concepts disclosed by the present invention.
SUMMARY OF THE INVENTION
By the present invention, an improved anchor system for completed structures is disclosed.
Accordingly, one of the objects of the present invention is to provide an improved anchor system which is adaptable to secure or anchor the components of a completed building structure to the earth or foundation of the structure.
Another of the objects of the present invention is to provide an improved anchor system which is particularly adaptable to residential structures having sloped roofs, e. g., single family residences, townhouses, and associated structures, such as garages and sheds.
Yet another of the objects of the present invention is to provide an improved anchor system which provides external means for securing the shingles of a shingled roof against wind damage.
Still another of the objects of the present invention is to provide an improved anchor system which provides means for externally securing the roof structure of a building to the upper wall structure of the building.
A further object of the present invention is to provide an improved anchor system which also provides external means for securing the roof structure of a building directly to the ground or to the foundation of the structure, thus also securing the walls between the roof and the ground or foundation.
An additional object of the present invention is to provide an improved anchor system which makes use of readily available materials and components.
Another object of the present invention is to provide an improved anchor system which utilizes threaded fasteners exclusively wherever fasteners are required.
A final object of the present invention is to provide an improved anchor system for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purpose.
With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel combination and arrangement of parts hereinafter more fully described, illustrated and claimed with reference being made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broken away perspective view of a sloped, shingled roof, showing the details of the shingle anchoring system of the present invention.
FIG. 2 is an elevation view in section of the upper wall and roof truss area of a structure, showing details of the wall to roof securing means of the present invention.
FIG. 3 is a perspective view of one side of a building structure, showing the means used to secure the roof structure directly to the foundation and/or ground.
Similar reference characters denote corresponding features consistently throughout the several figures of the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, the present invention will be seen to relate to a system providing for the securing of various components of a building structure together, and for the securing of a building structure to an underlying foundation or to the ground.
FIG. 1 of the drawings discloses a means of securing shingles on a sloped, shingled roof according to the present invention. It is well known that shingles are very susceptible to damage from storms with high winds, if the wind lifts the shingles and tears them away from the underlying roof sheathing. The problem lies in the securing of the lower edge of each of the rows of shingles on such a roof, as the upper edge of each row is secured beneath the adjacent overlying row up to the roof ridge. Accordingly, the present invention provides a means to secure the lower edge of each row of shingles by means of a plurality of transverse shingle securing lines or cables 10 which are installed laterally across the shingles S. Lines 10 are preferably installed a distance D approximately 11/2 inches up slope from the lower edge E of each row A of the shingles S, in order to preclude the lifting of any of the lower edges E of the shingles S. Lines 10 are secured at each end rafter ER (one of which is shown in FIG. 1; the opposite end of the roof of FIG. 1 will be seen to be essentially a mirror image of the end shown) by an eye bolt 12. Eye bolts 12 are provided with threaded lag screw ends and screwed through the shingles S, roof sheathing thereunder, and into the end rafter ER, with each end of each line 10 drawn taut across a respective row A of shingles S and secured around a respective eye bolt 12 by a braided eye 14. Preferably, each line 10 is formed of a braided polyester material having an open core in its relaxed condition, thereby providing for ease of formation of the braided eyes 14 at each end. The braided polyester material has been found to be relatively durable and resistant to sunlight and other potential causes of deterioration, and at the same time relatively economical. Other materials may be used if desired, such as stainless steel cable, and preferably stainless steel anchors such as eye bolts 14 are used in order to provide corrosion resistance and long life.
Each of the lines 10 is further secured to each of the other intermediate rafters R between the two end rafters ER, by a plurality of overlying straps 16 which tie each line 10 down at each rafter R. Each strap or clamp 16 is secured on either side of its respective line 10 preferably by a stainless steel spiral threaded roofing nail 18, with a third like nail 18 driven through the center of the strap 16 and through the line 10 thereunder to provide additional security. Straps or clamps 16 are preferably copper for corrosion resistance; however, other materials (e. g., stainless steel) may be used as desired. Thus, every shingle S on the roof is secured, as each row A of shingles S will have an overlying line 10 extending transversely thereacross approximately 11/2 inches up from the lower edge E. The lower edges E of the shingles are therefore prevented from lifting due to high winds or other causes, and yet the placement of the lines 10 a short distance D upward from the lower edges E of each row A of shingles S, serves to prevent the shingles S from curling back under the lines 10 to lift above the lines 10. The above discussed element of the structural security system of the present invention will be seen to be applicable to a completed structure, with no dismantling of any of the structure required for its installation on the structure. Moreover, one of the key elements of the present invention will be seen to be its use of threaded fasteners to secure each element or component; the use of standard, non threaded nails or the like is avoided. The threaded fasteners used throughout the system of the present invention provide a substantial increase in security between components thus secured.
While the above element of the system serves to prevent shingle damage or loss in high wind or storm conditions, and thereby prevent water damage to the interior of the structure and its contents, it does nothing to secure major structural components together to prevent major structural damage or destruction of the structure. One of the major causes of structural damage in extremely high wind conditions (hurricanes, severe thunderstorms and tornados, etc.) is the lifting and removal of the entire roof from the remainder of the structure. Considering that conventional frame structures rely primarily upon the weight of the roof to keep the roof in place, with the structure being secured only by a relatively few standard nails, it is not surprising that high winds can often remove a roof from a structure.
FIG. 2 of the drawings discloses a means for securing the roof of a structure to the adjacent upper walls. FIG. 2 discloses a section of a conventional framed structure, having substantially vertical wall studs W topped by a top plate P, with a ceiling joist J immediately adjacent and thereabove. A sloped rafter R is installed atop the joist J, in the conventional manner as shown in FIG. 1. However, rather than merely allowing the joist J and remaining roof structure to rest upon the upper plate P, an additional tie 20 is installed at the juncture of each of the wall studs W and ceiling joists J. These wall stud to ceiling joist ties 20 are installed externally to a previously completed structure, as in the case of the shingle securing system discussed above. Each tie 20 is preferably formed of a strap of stainless steel some 11/2 inches wide, or equal in width to the standard 11/2 inch thick "two by fours" generally used for wall stud construction. A right angle bend is formed in the strap or tie 20, enabling the tie 20 to be secured to both the upper portion of the wall stud W and also to the ceiling joist J and rafter R thereabove. By providing a strap or tie of some eight inches in length, the majority (preferably some five inches) may be secured to the vertical wall stud W, with the remaining length secured to the adjacent joist J, or through the adjacent joist J and into the rafter R thereabove. Threaded screws or bolts of sufficient length to penetrate substantially the majority of the depth of the secured members are provided, such as the lag bolts 22 shown in FIG. 2. Bolts 22 are again preferably formed of stainless steel for corrosion resistance and long life; however, other materials may be used if so desired. It will be noted that the lag bolts 22 penetrating the wall studs W are somewhat shorter than the lag bolts 22 penetrating the ceiling joist J and rafter R, due to the greater depth of material provided by the ceiling joist J and rafter R. By providing bolts 22 of proper length, it will be seen that all three of the major structural elements shown in FIG. 2--the wall stud W, the ceiling joist J, and the rafter R--may be tied together with a single tie 20. This provision of a single tie 20 to secure together all of the above elements, provides for additional security for a structure so secured. Further security may be provided by securing an additional bolt (not shown) into the upper plate P, immediately beneath the ceiling joist J. While the thickness of the soffit immediately beneath the eaves may not allow sufficient depth along the exterior wall for such an additional bolt, in many cases a double upper or top plate is installed and the three inch thickness thereby provided, serves to provide sufficient depth for an additional lag bolt into the lower one of the double top plate members.
For even greater security, the tie 20 may be provided in a longer length, having an extension 20a which may be bent to an angle complementary to the slope of the rafter R and secured directly thereto with additional bolts 22. The bolts 22 secured directly into the end of the rafter R and through tie extension 20a, serve to provide additional security over the portion of tie 20 which is held by bolts 22 which are secured indirectly to the rafter R through the joist J. In any case, the provision of means to secure each of the above structural components together by means of threaded fasteners 22, provides for a major strengthening of the upper portion of the structure.
While the above two elements of the present invention serve to secure the shingles to the roof of a structure, and to secure the roof of the structure to the upper walls, even further security is required in some cases. The present invention further provides for the securing of the roof structure directly to the foundation F or to ground anchors 24, as shown in FIG. 3. FIG. 3 discloses a plurality of eye bolts 12 which are screwed into the rafters R from the bottom, preferably on the order of four inches outward from the exterior surface of the wall. In order to preclude blockage of doorways, windows or other areas as desired, no eye bolts 12 are provided in those rafters R directly in front of such areas.
A like plurality of anchor points is provided in the foundation F or in the ground adjacent the foundation F, as desired and as appropriate for the conditions. In FIG. 3, a plurality of ground anchors 24, comprising large masses of concrete or other suitable anchor means (e. g., buried steel anchors or columns), with tiedown eyes 26 extending therefrom, is shown to the right side of the drawing, while additional eye bolts 12 are secured into the foundation F by means of lag shields or other suitable anchor means. Preferably, the underlying structural anchor means provided by ground anchors 24 are installed no more than six inches outward from the perimeter of the structure, in order to keep all tiedown lines or cables 28 close to the structure and substantially parallel to the walls, thus avoiding entanglement with such lines 28 by a person working near the exterior walls of the structure (e. g., gardening, etc.) The precise distance out from the walls for the installation of the eye bolts 12 into the rafters R, and the placement of the ground anchors 24 and foundation eye bolts 12, may be adjusted in order to ensure that the tiedown lines or cables 28 are substantially parallel to the walls and relatively close to the structure when installed.
A plurality of tiedown lines or cables 28 equal to the number of eye bolts 12 installed in the rafters R along the eaves of the structure, is then installed, drawn taut in the manner of the shingle securing lines 10, and secured at opposite ends to a respective rafter eye bolt 12 and ground anchor tiedown eye 26 or foundation eye bolt 12, as appropriate, by means of a braided loop or eye 14, as shown in FIG. 1. Roof or rafter tiedown lines 28 are preferably formed of the same material as the lines or cables 10 used to secure the edges of the shingles S, as shown in FIG. 1. It will be seen that the securing of the rafters R directly to any underlying structure comprising the foundation F or ground anchors 24, results in the remainder of the roof structure, the wall structure, and any other interposed structure, being captured between the roof rafters R and the foundation F or ground anchors 24. Moreover, while each individual tiedown line or cable 28 may not provide sufficient strength to secure a large structure in a high wind, the plurality of cables or lines 28 provided by the present invention will be seen to provide sufficient strength and security to secure an average frame structure under most conditions of wind and storm which might be anticipated in most areas.
Accordingly, it will be seen that the present invention provides for the complete securing of a one or two story frame structure having a sloped, shingled roof, to the ground or to its own foundation to preclude shingle or roof damage, removal of the roof from the rest of the structure, or displacement of the structure from the foundation due to severe storms and high winds. The present invention lends itself well to single family homes and similar or related structures which have already been completed and which have been permanently and immovably constructed on a building site. The use of only external anchor and tiedown means, as well as the exclusive use of threaded fasteners and anchors throughout the present invention, results in a system which is both simple to install and which is also extremely durable and secure.
It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.
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A system for securing a building structure, and various components of a building structure, to one another and/or to the building foundation or ground, is provided. The system includes apparatus for securing shingles against wind damage on a sloped, shingled roof; apparatus for securing the roof structure of a building to the adjacent upper wall structure; and apparatus for securing the roof structure directly to the foundation of the building or to the ground. The system is particularly adaptable to single and two story residential dwellings, such as single family homes and townhouses, and their related structures, such as garages and sheds, having sloped, shingled roofs. Installation of the complete system of the present invention provides substantial additional security for a structure against storm damage, particularly due to high winds.
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention concerns unique means for marking or promoting the various rankings of students or other participants of the martial arts and particularly concerns specialized self-adhesive, colored vinyl strips for marking the waist belts worn by such participants.
2. Prior Art
Colored adhesive strips arc commonly used in martial arts training to indicate rank or achievement of the participant. Currently, instructors cut or tear such strips from rolls of colored tape and wrap them on the student's belt, or stick them to something else for later use. The tape material used in such rolls however, is too thin, too stretchable and too deformable to maintain a clean rectangular shape of the tape throughout the cutting/transfer process. Further, the tape glue tends to seep out or become exposed due to shrinkage of the strip, which leave a sticky residue and collects dirt. Also, there are a limited variety of colors available, and those are usually flat, matte, or otherwise have a dull finish.
Some means must also be in place to store and use the various colored rolls or tape. One common method is to install a rack on the wall in the training area where awards will be given to hold the rolls and a pair of scissors or a knife. This makes it possible for the instructor to cut a strip, albeit of non-uniform length, of the appropriate color and immediately place it on the student's belt. However, this can be a safety hazard particularly for children training in that area and also, the steps involved are time consuming which can present a real problem for large classes of participants. One alternative is to store and cut strips in another area in advance, then carry them to the floor to be distributed. Handling the cut strips then becomes a time consuming problem. The strips also can be stuck to something such as a piece of plastic, but they are difficult to remove and unsightly due to variations in size and placement. Some instructors stick the cut strips to their own clothing temporarily to carry then to the floor. Aside from being even more unsightly, the strips pick up dirt and lint and may not stick well when applied.
Regardless of how the strips are transferred, someone must cut each one by hand, and this is both tedious and time consuming, which can be costly in terms of labor and morale. The irregularity of hand cut strips also leads to a costly waste in material. Overall, the current methods and material being used are inefficient and lead to poor quality results.
BRIEF SUMMARY OF THE INVENTION
The invention in one of its principal utility embodiments is defined as a martial arts belt of fibrous construction having an undeformed contour of a generally flat, thin and narrow configuration with a length of at least about three feet, wherein said belt is comprised of multi-layered fabric, which layers are multi-stitched in a longitudinal direction to impart semi-rigidity to said belt, said belt being sufficiently flexible to be tied in a knot, wherein at least one adhesive strip of colored and substantially non-stretchable vinyl material is contact adhesively secured to and generally laterally girdles said belt on the undeformed contour thereof, and wherein end portions of said strip are overlapped and adhesively secured to each other at the overlap.
In on preferred embodiment, the vinyl material has a thickness of from about 2.5 to about 5.0 mils, a width of from about 0.3 to about 0.9 in., and has a “Stretch Modulus” of less than about 0.1 and most preferably of from about 0.01 to about 0.0005. In a most preferred embodiment the strip width is from about 0.4 to about 0.6 in., and the thickness is from about 3.0 to about 4.5 mils.
Our objective was to solve all of the above mentioned problems which has been achieved by a method including employing a heavier and more attractive vinyl, a cleaner acrylic adhesive, pre-cut perfectly sized strips, on silicon coated paper for easy removal and pages of the strips hole punched to fit any available ring binder. The vinyl we use does not stretch or distort easily, making it easier to apply neatly to the student's belt. The adhesive does not seep or squeeze out from under the applied strip, nor will the strip shrink significantly such as to expose glue residue. A wide variety of colors are available with a much more attractive finish, making the present product especially appealing and useful as a reward to participants, especially to children.
The strips are used to indicate completion of certain levels, tasks, or mastery of certain skills in the martial arts. The pages or loose-leaf binders are carried to the floor where each strip can be easily removed from the release liner for use. hey are wrapped around the end of the uniform belt, adhesive backing against the belt, in such a way that the strip ends overlap slightly, e.g., 0.25-0.75 inches, providing a secure but releasable bond therebetween.
The product is mass-produced in a ready to use form which completely eliminates the need for any sharp or bulky objects on the training floor. The labor and waste involved in hand cut strips is eliminated, and any unsightly or inefficient method of storing, carrying, and using the strips is replaced by a neat, clean, easy to use sheet which can be inserted into a binder along with as many different colors as may be needed. The cost is therefor considerably less, and the end result is an efficient, attractive marking system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a promotional strip page embodying the present invention;
FIG. 2 is an enlarged cross-sectional view along the section line 2 — 2 of FIG. 1;
FIG. 3 is a perspective view of a second embodiment of promotional strips for martial arts belts fabricated in a continuous roll configuration;
FIG. 4 is a perspective view of a martial arts belt depicting the typical placement of promotional strips thereon;
FIG. 5 is a perspective view of a promotional strip page assembly in a typical three ring binder;
FIG. 6 is a side view of a device for determining the stretch modulus of the present vinyl strip; and
FIG. 7 is a front view of the device of FIG. 6 taken in the direction of the arrow 7 .
DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 depicts a first preferred embodiment of the promotional strips assembly or loose-leaf product labeled as item 10 . This assembly consists of a release liner 12 with a number of removable, self-adhesive pre-cut strips 14 . The release liner is punched in a standard three-ring pattern 16 to facilitate storage and use of multiple pages. The strips 14 are preferably scored along line 18 to divide the vinyl without cutting the release liner.
FIG. 2 shows the strips 14 in cross section with a pressure sensitive acrylic adhesive coating or backing 20 on one side and releaseably adhered to a thin film of silicon 22 on the paper release liner 12 surface to securely hold the strips until ready for use. The release liner need not be paper or specifically silicon coated as many other products are readily available which would be suitable for this purpose. The vinyl strips 14 can be any of a number of colors readily available from manufacturers such as those mentioned below. The vinyl surface may also be treated as at 24 to be print receptive if text or a logo is desirable in addition to any colored background.
In use, one or more strips 14 with adhesive coating 20 thereon are removed from the release liner 12 and wrapped around the end of a student's uniform belt 26 as shown in FIG. 4 with coating 20 against the belt with the ends of the strip overlapped to provide a secure adhesive joint. A key characteristic of the strip 14 arises at this point. As previously described the thickness, Stretch Modulus and other properties and construction of the present strip maintains the rectangular form which allows the user to wrap the strip around the belt and bring the ends into an overlapped adhesively secured condition to provide a neat, clean, straight and attractive marking. The page or pages 10 of strips will typically be inserted into a three-ring binder as depicted in FIG. 5, and carried to the training floor for use during a promotion ceremony.
Another embodiment of this invention is depicted in perspective FIG. 3 in which the individual strips are produced in continuous roll form. The aforementioned basic characteristic of vinyl strips 14 , adhesive backing 20 , and release liner 12 remain the same. Regardless of the particular size, configuration or composition one may employ to practice the present invention, the intended usefulness and performance of this invention has been demonstrated. Anyone having ordinary skill in the art would be able to obtain the needed material from any of a number of commercial vendors to reproduce the quantities and characteristics of the above described invention.
The present strips are manufactured from calendered vinyl sheet stock with pressure sensitive acrylic adhesive on one side. The stock is commonly available on rolls of coated paper release liner from manufacturers such as FDC or 3M. The strips are produced by feeding the stock through a computer controlled cutting machine that precisely cuts the vinyl without cutting the release liner. Excess vinyl is stripped away leaving on the release liner in economical and utilitarian arrangement only the pre-cut approximately 0.75″×4.5″ rectangles. The standard size 3-hole loose-leaf page is then cut from the release liner. The best method we have found for producing this strip product is by a flexographic die-cutting machine capable of processing the rolls of stock into the finished product with very little human attention required.
Referring to FIGS. 6 and 7, the “Stretch Modulus” is determined by a device 28 employing a digital scale for applied distortion force, e.g., 1.0 Kg. This device preferably comprises a digital pull force read out scale 30 , clamps 32 , 34 for gripping end portions of a strip with adhesive backing 20 thereon, a worm gear 36 and wheel gear 38 and crank 40 . A longitudinal (linear) stretch ruler 42 and lateral contraction ruler 44 are mounted on the frame 46 of the device to give real time visual measurements of the degrees of distortion of the strip.
A set of such values is given in the table below:
Stretch Modulus Values
Typical colored
2.2 mil
SAMPLE*
tape 3.0 mil
vinyl tape
3.5 mil
4.2 mil
Linear
4% @ 1 kg
8.5% @
1% @
0.2% @ 1 kg
distortion
1 kg
1 kg
Lateral
6% @ 1 kg
16% @
0.3 @
0.0% @ 1 kg
distortion**
1 kg
1 kg
2.7% @ 3 kg
5% @
3 kg
Stretch
.05
.123
.007
.001
Modulus***
*All test samples measured 3.85 in., long and 0.85 in., wide.
**3 kg is excessive force but is shown to demonstrate the level at which appreciable distortion occurs with a preferred strips.
***“Stretch Modulus” is defined as the percentage of the average of lateral and linear distortions per applied force. The lateral distortion is measured at the point “P” of maximum lateral contraction.
The foregoing description including the best mode contemplated for carrying out this invention is provided for illustration purposes only and not for the purpose of limitation, the invention being defined by the claims. The invention has thus been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications will be effected with the spirit and scope of the invention.
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Promotional strips for martial arts belts comprised of a thin flexible vinyl sheet material of specifically designed properties and characteristics to easily and attractively mark a uniform belt. The strips are pre-cut and releaseably attached to a carrier sheet. Each strip is coated with a thin film of pressure sensitive adhesive on one side for securely attaching to a belt. A wide variety of colors as well as printable surface are available.
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This is a division of application Ser. No. 894,855, filed Aug. 8, 1986, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a document storage and retrieval system for filing documents as an image, and is particularly concerned with a document storage and retrieval system capable of full text searching.
The typical information retrieval system has hitherto provided a retrieval of data chiefly according to a keyword and a classification code. Bibliographic information and patent information have been processed to form a data base by means of the system mentioned above. Mainly bibliographic information including abstracts in its coverage is processed for a data base here, but the situation is such that only a part of its function is realized to cope with the true need of information retrieval. That is, even if a document or patent conceivably relevant is found, there is the need to search among a lot of bookshelves to obtain the text.
Meanwhile, an optical disk capable of storing a mass data has now been available for loading the text in the data base to provide a so-called original document information service, thus coping with a social need. A paperless documentation at the Patent Office is so planned accordingly. In these systems, volumes of documents are stored in optical disks in the form of image data, and a conventional information retrieval technique based mainly on a keyword search is applied.
However, the conventional information retrieval technique is only effective to orders of tens to hundreds, and hence a further technique for squeezing relevant documents to 1/10 in number or so is desired. One method is that in which an original document (text) stored as image data is called onto a terminal and read visually by a retriever. The method is secure in principle, however, documents amounting to hundreds maximumly are too many to read out in the form of image data, and reading one by one visually is not efficient practically as a matter of course.
On the other hand, the conventional method based on the keyword and classification code must be updated all the time for the classification system itself changes as time passes, thus leaving an intrinsic problem. For example, volumes of documents classified already cannot be modified practically as the classification system is subjected to modification later. Documents and patents recording a progress of science and technology are novel in content and hence of value because they provide a new data conception which often is not included in the conventional classification system. For this purpose, it is impossible to define beforehand the keyword and the classification system representing a conception originally, which is a problem essentially for the information retrieval system.
For the reason as mentioned above, it is desirable to provide a method which will retrieve contents with reference directly to the text of a document. According to the method for referring to the text, a retrieval can be practiced by means of a vocabulary recognized as a conception which was not deemed to be important when the document was registered in a data base but is taken new at the point of time of retrieval. Or otherwise, an important document can be searched out directly without a "filter" or an indexer (specialized for giving index) at the time of registration.
To satisfy such a requirement, it is necessary that a character pattern is extracted from the document as an image data and the text is replaced by a character code, and a character recognition technique may be applied therefor. However, a document or a printed document, for example, which is an object for filing is not perfect character recognition from the point of view of diversification of the kinds of print quality and font. In a conventional optical character reader, imperfect recognitions such as error, rejection and the like are subjected to checks and corrections by operators. (For example, "Introduction to Character Recognition" by Hashimoto, Ohm-Sha, 1982, pp. 153-154) Accordingly, even if the recognition precision is extremely high, a method for checking visually a result obtained through recognizing the text is not realistic where the amount of documents is very large, and hence a document filing system with images as the main constituents which is available for text retrieval has not been realized until now.
SUMMARY OF THE INVENTION
An object of the invention is to provide a document storage and retrieval system having a full text retrieval function with reference directly to the text of a document by solving the problems referred to above.
In order to attain the above-mentioned object, the invention the invention stores and retrieves both the document image data and full-text data, where full-text data is used to support the full-text search capability, and the image data is used to present or display the contents of the retrieved documents to the retriever. This system inputs character strings as the retriever's request, and searches for these strings in character strings in the full-text data. By searching for the corresponding image file identifiers in the image file directory, the locations of the corresponding document image data are identified and the retrieved document images are displayed onto the document retrieval terminal.
This system further recognizes the contents of the documents from the image data and stores the resulting text data to support the full-text retrieval capability. To overcome the problem of insufficient character recognition accuracy, the character recognition module of this system outputs multiple candidates of character codes when more than one characters have very high similarity values, thereby avoiding misrecognition. The full-text data so created therefor includes some ambiguity. For example, an ambiguous text is represented as ". . . S[mw] [il] th . . . ", where [mw] represents two character, and "m" and "w" which are the candidates for the recognized character, and [il] represents "i" and "l" which are the candidates having the most similarity. The full-text search mechanism of this system can identify that a substring "Smith" is included in the string documents with high accuracy even from the full-text of the document recognition results.
As shown in FIG. 1, a document 10 is transformed into a notational expression as indicated by 20 in the system according to the present invention. The symbol string used is that provided in languages such as LISP. It follows a notation called S-expression. A process in which the document (image) is transformed into a notational expression 20 is called document understanding or document recognition. The notational expression signifies roughly the following. That is, the document is numbered 99, the class is "Technical Paper" , VOL=5, NO=7, the author is named "Peter S[mw] [il]th" , the title is "Fu[1l][l1]ΔText≢[RB]etr[il]e . . . ", the text is ". . . Fu[l1][l1]ΔTextΔse[ao]rch . . . " and so forth. Here, Δ indicates a blank (space) and so forth.
In the character recognition, that of ambiguity includes, in most cases, a character pattern which can hardly be coped with normally.
For retrieval, meanwhile, a user inputs "FULLΔTEXTΔRETRIEVAL" from a keyboard. Generally, there are such languages as will express the same meaning in different words, and in this case "FULLΔTEXTΔSEARCH" has also the same meaning. While handling such ambiguity automatically, the system is capable of searching documents having the same character string.
A plurality of partial character strings to be found out of the sentence to be retrieved are expressed by a finite state automaton as shown in FIG. 2. The title character string which is one of the sentences to be retrieved as exemplified in FIG. 1 can be expressed similarly by the automaton of FIG. 3. In this case, however, there is no distinction between a capital letter and a small letter. The invention provides a text search (character string retrieval) function in case there is present an ambiguity (a plurality of possibilities, or the state wherein elements which cannot be decided identically are present) on both searching key (partial character string) and sentence to be retrieved, which is a third principle.
A method given in a report [by A. V. Aho, et al. "Efficient String Matching: An Aid to Bibliographic Search," Communications of the ACM, Vol. 18, No. 6, 1975] is well known for searching a plurality of partial character strings out of an unambiguous text by the infinite state automaton.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing a document image and a result of document understanding;
FIG. 2 is a state transition diagram of a synonymic character string generated from a partial character string;
FIG. 3 is a state transition diagram of a character string as a result of character recognition which includes ambiguity;
FIG. 4 is a system configuration drawing of a first embodiment;
FIG. 5 is a table of the main directory keeping the bibliographic data;
FIGS. 6(a) and 6(b) together shows tables for storing location information of text data and image data;
FIG. 7 is a table storing publication information;
FIG. 8 shows an image file directory and its relationship with the body file;
FIG. 9 shows a text file directory and its relationship with the body file;
FIG. 10 is a block diagram of a document recognizer;
FIG. 11 is an explanatory drawing of a rectangular area surrounding a character pattern;
FIG. 12 is a drawing illustrating a contour expression method for describing a pattern;
FIG. 13 is a drawing illustrating a relation between pattern components and character pattern;
FIG. 14 and FIG. 15 are drawings showing a result of segmenting rows and columns respectively by means of a bottom-up segmenter;
FIG. 16 is an explanatory drawing of an algorithm for obtaining a state transition list from a character string aggregation;
FIG. 17 is a block diagram of a flexible string matching circuit;
FIGS. 18(a) and 18(b) together is an extended finite state automaton permitting an ambiguous character string;
FIGS. 19(a) and 19(b) together is a state transition table of the extended finite state automaton;
FIG. 20 is a drawing illustrating a program of FSM circuit;
FIG. 21 is a configuration drawing of a flexible string matching circuit in a second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described with reference to illustrative examples. FIG. 4 is a configuration drawing of a document storage and retrieval system forming one embodiment of the invention. The system comprises a control subsystem 100 providing a general control and a data base function, an input subsystem 200 for inputting a document and others and registering in a file, a document recognizer 300 for recognizing documents, a text search subsystem 400 for carrying out a high-speed text search, and a terminal subsystem 800 for carrying out a retrieval.
A configuration and a flow of operation of each subsystem will be described in detail below.
The input subsystem 200 has a central processing unit (CPU) 201 for controlling the subsystem, a main memory 202, a system file 251 and a terminal 203 as a basic division. The subsystem is controlled by operation from the terminal 203, image on each page of a document 220 is read optically by a scanner 221, and digitized image data is stored first in a video memory 224 by way of a bus 210. The image data is then subjected to a redundant compression on an image processor (IP) 223, transformed into MH (Modified Huffmann) code or MR (Modified Read) code and then returned to another area of the video memory 224.
The inputted document image is displayed on the terminal 203 for confirmation, and the operator is capable of inputting bibliographical items such as the title, author's name, creation data and others while observing the image displayed thereon. As will be described hereinlater, bibliographical items of a formatted document can be read automatically through document understanding, however, bibliographical items of a not-formatted document and items of information which are not entered in paper must be inputted manually. For example, it is natural that a classification code of document contents defined by users and a keyword which is not present on paper should be inputted by the operator. Then, a value and position setting of each document must be arranged independently by a user of the document, which can be inputted from the terminal 203. A data of such bibliographical items and others inputted as above is correlated with an image data (compressed data) in the video memory 224 and is then loaded in the main memory 202.
Here, each document is given a proper number (document ID) and stored in the memory so as to draw image data and bibliographical items using the proper number of the document as a key. The document proper number can be expressed, for example, by coupling an identifier number (`INSYS 01` and the like) of the subsystem to the character string indicating date and time. For example, INSYS01. 850501.132437 indicates a document inputted from an input subsystem INSYS01 at 13 h: 24 m: 37 s on May 1, 1985. There may be a case where the input time is important according to application of the system, and hence it functions as a time stamp otherwise.
Now, whenever a predetermined quantity of the document is accumulated in the subsystem 200 or a predetermined command arrives from the terminal 203, an interrupt signal is sent to a bus adapter 171.
A control subsystem 100, sensing the interrupt signal, reads a predetermined address in the memory 202 of the input subsystem 200. The contents of a request of the input subsystem can thus be decided.
An operation follows as described below upon request of a registration of the inputted document in a data base.
The central processing unit (CPU) 101 is acquainted with the proper number of documents stored temporarily in the input subsystem 200 according to a predetermined program in a main memory 102 and further with a memory address of bibliographical data (bibliographical items) relating thereto and image data.
The control subsystem 100 has a data base file 151 for storing and managing symbolic data such as bibliographical data and the like, and an image file 152 for storing and managing the image data.
The bibliographical data read out of the input subsystem 200 is written as a new record in a data base (loaded in the file 151) which is given in the form of the table in FIG. 5. The table of FIG. 5 is named MAIN-DIR (main directory) and has the following data columns.
______________________________________DOC#: A serial number of document registered in the systemID: A document proper number given by the input subsystem.NP: A page number constituting the document.TITLE: A title (character string)AUTHOR: An author's name (permitting iteration of plural data).CLASS: A symbol indicating classification, kind and the like of documents.PUBL#: A number of publication registered in the system (detail being managed on the table shown in FIG. 7.)VOL, NO, PP: Volume, number, page.KWD: A plurality of keywords.ABS: A text proper number of abstract expressed as a character code string (text data).TXT: A text proper number as a character code string.IMG: A proper number of image data. Since the image data is managed at every page, a plurality of image proper numbers are recorded.______________________________________
In registration of the bibliographical data, only such data of the above columns as will relate partly to the bibliographical data is written newly.
Next, the image on a page constituting each document is read to the control subsystem 100 from a predetermined storage area of the input subsystem and is then stored sequentially in an empty area of the image file 152. Each image (page unit) is concurrently given an image proper number (IMGID). Then, a volume number (VOLSER) of the file having loaded the image data therein, a file unit number (UNIT), a loading physical address (PHYSA) in the file, a record length (SLENG) in the file and others are written in tables shown in FIG. 6(a) and FIG. 8. The image proper number INGID given newly is also recorded in IMG column of the table MAIN-DIR (FIG. 5).
Here, a table IMG-LOC shown in FIG. 6(b) is particularly effective when the image file 152 is constituted of a plurality of driving devices or a plurality of volumes, managing the location of each image. As a matter of course, it is updated at every operations for demounting and mounting the volume by operators.
Then, FIG. 8 shows a directory provided at each volume of the image file 152, and the following columns are provided therein.
______________________________________IMGID: An image proper number.PN: A serial page number (l to n) in a document.PHYSA: A physical address in a volume.SLENG: A record length (sector number, for example).CODE: An image compression code name.SIZE: An image size (pixel number).DOC#: A document serial number.______________________________________
Then in the drawing, data in the column PHYSA of a record 157 indicates a leading address of an image data 158 in an image data area 156 in the image file.
Now, whenever the above operations come to end, the system is ready for retrieving the bibliographical items and the keyword from the terminal group 800.
A retrieval condition inputted from the retrieving terminal is transmitted to the CPU 101 of the control subsystem 100 by way of a gateway 175. A retrieval of a table MAIN-DIR (FIG. 5) in the data base file 151 is carried out according to a predetermined retrieving program of the memory 102. It goes without saying that indexing (for high-speed retrieval such as hashing, inverted file and the like) is applied to main columns of the table MAIN-DIR.
As a result of retrieving, a list of DOC#from the table MAIN-DIR (FIG. 5) and a list of image proper number IMGID are made out and stored in a predetermined area of the memory 102. Upon request for display from the retrieving terminal, a position in the image file is identified by means of a table IMG-LOC 154 (FIG. 6(b)) and a table IMG-DIR 155 (FIG. 8), and the image data is read successively onto the memory 102. The image data thus read out is transmitted to the retrieving terminal in turn and then displayed on a screen according to an indication on the terminal.
A managing method for the text used for full text retrieval will be described, next.
As described in the main directory MAIN-DIR (FIG. 5), each document is stored and managed not only for image data but also for text expressed in a character code string. In the example, the abstract and the text are stored and managed in text files 451, 452, 453 as a text. Each text (character string) is given a proper text number and recorded in columns ABS and TXT of the table MAIN-DIR (FIG. 5), a column TXTID of the table TXT-LOC shown in FIG. 6(a), and a column TXTID of the table TEXT-DIR shown in FIG. 9.
FIG. 9 indicates a method for storing and managing texts in the text files 451, 452, 453. In the drawing, a text body is stored one-dimensionally in a file storage area 466. Each text (one character string) is given a proper number TXTID and managed in a directory table TEXT-DIR 465.
______________________________________TXTID: A text proper number.NCH: A total number of characters constituting the text.PHYSA: A physical address in which the text is recorded.SLENG: A record length on a storage medium of the text.CCLASS: A class of characters expressing the text (Chinese character-mixed Japanese statement, English statement, Roman character, kana character and others).______________________________________
A record 467 of the table 465 indicates that the text expressed by the record is a portion 468 in the storage area in the file.
On the other hand, as shown in FIG. 4, the text can be recorded in a plurality of volumes, and the text directory is that of managing the text in each volume. When the plural volumes are mounted, it is necessary that a presence of a text in any of the volumes be known, and the table TXT-LOC shown in FIG. 6(a) manages the location of each text. A volume serial number VOLSER in which the text having the text proper number TXTID is recorded, and a file unit number UNIT in which the volume is mounted is managed. TXT-LOC will be updated automatically as a matter of course when a physical volume is demounted or newly mounted by operators.
Then, when input of document images, input of bibliographic items and registration of documents are over as a flow of big operation, a text recognition (document understanding) of the registered document is carried out by the document recognition apparatus 300. An input of the recognition apparatus is the document image 10 shown in FIG. 1 in an image file 152, and a recognition result output is a notational expression 20 shown likewise in the drawing. A text portion of the abstract and the text in the notational expression 20 is stored newly and so managed by the text files 451 to 453 as described hereinabove.
The document recognition will be described with reference to a detailed block diagram of the document recognition apparatus shown in FIG. 10.
The recognition apparatus 300 is connected to a bus 110 of the control subsystem 100 through a bus adapter 371 and controlled by CPU 301. A memory 302 stores data of a program and a parameter for controlling operation of the apparatus.
An image data to be recognized is transmitted from the image file 152 to a memory 321. The image data is coded through compression, decoded to a bit expression image by an image processing circuit IP 322 and is again stored in the memory 321. Then consecutively, a contour extraction of the pattern is carried out by the IP 322 from the image decoded to a bit expression, and a result of extraction is again loaded in the memory 321.
The extracted contour data is expressed as follows: ##EQU1## where i represents a contour proper number (1, 2, 3, . . . ), and Ci represents a class of the contour. Then, Ci=0 represents an outer contour (a full line 1001 in FIG. 11), and Ci=1 represents an inner contour (a broken line 1002 in FIG. 11). Those x max , x min , y max , y min represent a coordinate of the vertex of an outer quadrangle of the contour, each, as shown in FIG. 11. Further, (x s , y 2 ) is a coordinate of one point Ps of the contour length (or, for example, the point found first by contour retrieval). With the point Ps as an origin, as shown in FIG. 12, the contour data itself is expressed by rows of sets of a quantized direction code θ and a pixel number L with the same direction continuing therefor.
Next, an inclination correction circuit 323 detects a tilt angle arising at the time of document input from the contour data given by the expression (1), corrects the contour data accordingly and then rewrite it to the memory 321. For example, a system disclosed by the inventor in Japanese Patent Application No. 152210/1985 may be employed for the inclination correction algorithm.
From a portion of the contour data corrected for inclination (x max , x min , y max , y min ), a raw segmentation and a column segmentation are carried out on a bottom-up segmenter (BSG) 324.
The bottom-up segmenter BSG inputs the data expressed in the form of expression (1), generates a pattern list given by the expression (2) and loads it in the memory 321.
(j x.sub.max,j x.sub.min,j y.sub.max,j y.sub.min,j) (2)
Here, j represents a pattern proper number, the pattern is defined as a rectangular area not overlapping mutually, and the expression (2) further defines vertex coordinates of the rectangular area. For example, rectangular areas 1008, 1009 indicated by broken lines in FIG. 13 are inputs of the BSG, however, a rectangle 1010 is obtainable through the BSG. The rectangles 1008, 1009 are made of one contour each to be an element, and the rectangle 1010 is a pattern forming one character. An element constituting the pattern j is obtainable through searching the rectangle included in a rectangular area defined by the expression (2) from the contour data of the expression (1). It can be obtained separately and loaded as data. A result of row segmentation and another result of column segmentation are shown diagrammatically in FIG. 14 and FIG. 15 respectively.
A character segmentation division (CSG) 325 extracts the pattern constituting a character from the above pattern list with reference to a document knowledge arranging regulations such as document form and the like. As shown in FIG. 10, the document knowledge is loaded in a document knowledge file (DKF) 327.
Structural regulations of the layout of such as a title, author's name, author's belonging, abstract, text and the like are stored according to each kind of documents in the document knowledge file together with a parametric knowledge such as the size of font. The knowledge is described in a format description language. The language disclosed in Japanese Patent Application No. 122424/1985 may be used as a format description language.
The character segmentation division CSG operates for integration of a pattern constituting one character which has been divided into two patterns or more or, to the contrary, for compulsory separation of two or more characters which has been fused through contact into one pattern.
The character segmentation division CSG outputs the number of the patterns constituting each character in a list for each item such as the title, abstract or text as the result of processing. For example: ##EQU2## represents that the abstract is constituted of a string of characters expressed by a pattern number j k . Here, [j n j n+1 j n+2 ] represents that the character can be any of three patterns j n , j n+1 , j n+2 .
A character recognition division (CRG) 331 extracts the contour data constituting each character pattern, as described hereinabove, from the above-mentioned pattern list (expression (3), for example) and the contour data (given by expression (1)) on the memory 321, and transforms it into a data structure ready for feature extraction.
Since a known art may be employed as the character recognition technique, a detailed description will be omitted here, however, after a feature is extracted from the contour data, each character can be recognized through a pattern matching with the standard pattern in a standard pattern file 333. In FIG. 10, a memory STPM 334 is one for storing a standard pattern with high reference frequency, aiming at a high-speed processing.
The result of the character recognition is output, as described hereinabove, by the notational expression 20 shown in FIG. 1. In the process of final decision in the character recognition, when a similarity obtained as a result of pattern matching satisfies an expression (4), a character category (character code) ω k for giving the similarity is output. ##EQU3## where ρ k is a similarity to the character category k, k is a total category number, and ε is a relative threshold.
If the expression (4) is not satisfied, then an aggregation of the character category {ω k |k=k 1 , k 2 , . . .} satisfying an expression (5) is output within two special character codes. For example, a character (code) string ω s ω k1 ω k2 . . . ω e is output. Here, ω s represents "[", and ω e represents "]". ##EQU4##
In case a similar character is present and the expression (4) is not satisfied by the above processing, a recognition result "FU[L1][L1]ΔTEXTΔSEA [RB]CH" is obtainable, for example, in response to the input pattern "FULLΔTEXTΔSEARCH". The recognition result is buffered on the memory 321 and then transmitted to the memory 102 (FIG. 4) collectively.
In the control subsystem 100, a maximum text proper number is detected with reference to the table TXT-LOC (FIG. 6), and a character code string (text) of the recognition result is registered with a value added by 1 as a new text proper number. The registration is carried out with respect to the main directory 153, the table TXT-LOC and the table 465 (FIG. 9), and the text data itself is loaded in any of the text files 451 to 453.
Now, the document to which a text data is given as above is ready for retrieving using the text search subsystem 400.
Next, the text search subsystem 400 for retrieving text contents and its operation will be described in detail.
A request for text content retrieval or ABS="TEXTΔRETREIVAL", for example, which is so made from the terminal 800 is transmitted first to the control subsystem 100. In the subsystem 100, where the document to be retrieved has already been narrowed down through keyword retrieval or other means, a proper number of the text incidental to the document is selected from the main directory MAIN-DIR 153, and an expression (6) for the list of proper numbers of the texts to be retrieved is made out according to each text file with further reference to the table TXT-LOC.
(u.sub.i v.sub.i (t.sub.il t.sub.i2 . . . t.sub.in))ptm (6)
i=1, 2, . . . , M
where u i is an i-th file unit number, v i is a volume serial number, t ik is a k-th text proper number to be retrieved on the volume. Then, M is a maximum number of the text file unit.
On the other hand, when the document to be retrieved has not been narrowed, a special symbol (expression (7), for example) is sent to the whole text file.
(u.sub.i v.sub.i *) i=1, 2, . . . , M (7)
The expression (6) or (7) and the partial character string ("TEXTΔRETRIEVAL", for example) are transmitted to a memory 402 of the text search subsystem 400 by way of a bus adapter 172.
In the subsystem 400 (FIG. 4), a hetero-notation generation processing and a synonym processing of the transmitted partial character string are carried out according to a predetermined program in the memory 402. A hetero-notation generation convention and a thesaurus are stored in a file 403.
"TEXT SEARCH" will further be obtainable through referring to the thesaurus. Further, with reference to the hetero-notation generation, a method disclosed in Japanese Patent Application No. 150176/1985 may also be employed.
As the result of the above-mentioned processing, an aggregation of character strings ("TEXTΔRETRIEVAL" "TEXTΔSEARCH") is obtainable, after all, to "TEXTΔRETRIEVAL". This is indicated by an expression (8). ##EQU5## where n is a number of character strings, m i is the length of an i-th character string, a ij is a character code j-th from the lead of an i-th character string A i .
The subsystem 400 further transforms the expression (8) representing the character string aggregation into a state transition list (9) representing the finite automaton illustrated in FIG. 2 according to a predetermined program. ##EQU6## where each element of the list a list (9) implies that when the character C ki is inputted (or coincides therewith) in the state S ji , the state can be transmitted to the state S li . Then in the expression, those which are equal to each other are included in {S ji , . . . , S ji , . . . , S jm }.
Further, an output list (10) expression is generated. ##EQU7## where (S jp A ip ) implies that the character string A ip is found at the point of time when reaching the state S jp .
FIG. 16 shows a PAD (program analysis diagram) of the algorithm for deriving the state transition list (9) and the output list (10) from the character string aggregation (8) expression.
Next, a failure transition list (11) expression is obtained from the state transition list (9).
f list=((S.sub.o S.sub.jo) . . . (S.sub.m S.sub.jm)) (11)
The element (S m S jm ) of f list specifies transition of the character C k inputted in the state S m to the state S jm with reference to f list when the state to be transmitted is not specified in a list (9) expression. It may be called generally a failure function.
The f list is provided so as to cope with the case where a reinitialization of the state to S o is generally not correct when a matching is successful halfway of a character string but the next character does not coincide in the partial character string matching, i.e., a destination of the predetermined state transition is not found. For example, a retrieval of two partial character strings "CHARACTERΔRECOGNITION" and "OPTICALΔCHARACTERΔREADER" is assumed. Supposing a sentence reading ". . . OPTICALΔCHARACTERΔRECOGNITION . . . " is inputted, a portion up to "OPTICALΔCHARACTERΔRE" coincides with the second partial character string but the next character "C" is not for matching. Here, if the state is returned to S o to resetting, the automaton processes the ensuing sentence "COGNITION . . . " as input characters, therefore the partial character string "CHARACTERΔRECOGNITION" will be overlooked after all. Accordingly, the state to be transmitted in the case of failure matching is not S o , but the state must stand as matching a transition pass "CHARACTERΔRE" of the first character string "CHARACTERΔRECOGNITION".
Then next, the subsystem 400 transmits the state transition list, a list, the output list, o list, and the failure transition list, f list, made out as described above to lower flexible string matching circuits FSMs 501 to 503.
A further detailed block diagram of the flexible string matching circuit 501 is shown in FIG. 17. (The block diagram applies likewise to FMSs 502, 503.)
The above-described three lists, a list, o list and f list, are loaded in predetermined areas of a memory 513 by way of an adapter 571. A microprocessor 511 generates an extended finite automaton shown in FIG. 18(b) in the form of state transition matrix on the above information according to a predetermined microprogram.
The finite automaton that the lists, a list and f list, directly imply has a simple form as shown in FIG. 18(a). The drawing illustrates two transitions ##EQU8## in the a list.
The microprocessor 511 extends and transforms the finite automaton shown in FIG. 18(a) to the one as shown in FIG. 18(b). The transformation is determined identically. A predetermined partial character string can be searched from the ambiguous text to be retrieved according to the transformation. Here, in the drawing, f(S j ) is a failure function made out of the failure transition list f list, indicating a state of the destination of transition when failing in matching at the sate S j . Then, the state W j corresponds one-to-one to the state S j , scanning the ambiguous character string (given within symbols [j). Further, the states T j1 , T j2 are states coming out of the state W j correspondingly to a transition from the state S j , indicating that the character being retrieved (C k1 or C k2 in the drawing) has been found in the ambiguous character string.
Practically, the microprocessor 511 is capable of generating the state transition table shown in FIG. 19(a) directly from the two lists, a list and f list. A column (vertical) in the state transition table indicates a current state, and a row (lateral) corresponds to a character (code) inputted under the state. The state to transit next is written in the table. Since the algorithm for generating the state transition table will be analogized easily from illustration according to FIG. 18, a further description is omitted.
The microprocessor 511 further transforms the output list, o list, into the form of an output table shown in FIG. 19(b) and records it in a predetermined area of the memory 513 together with the state transition table.
A string search algorithm using the finite state automaton is given as below.
String Search Algorithm
begin
γ=`false`;
S:=S o ;
While not eof do
begin
read (c);
S: next (c, S);
if out (S) <>nil
then γ:=`true`;
end;
end;
Here, the function next (c, S) is one for obtaining the next state from the state transition table shown in FIG. 19(a) on the character c and the current state S. Further, the function out (S) is one for deciding whether or not an output is present on the state S with reference to the output table shown in FIG. 19(b).
Then, the state is assigned to a unit of one character code in the above description, however, in case the one character code is 2 bytes like Japanese, it is divided into 1 byte each and then the above-described method can be applied thereto.
Next, the text search subsystem 400 accepts the lists (6) expression and (7) expression of the proper numbers of texts to be retrieved, and transmits them to the corresponding FSM as text proper number lists to be retrieved at each FSM. Accordingly, if there exists an object to search in the corresponding text file, each FSM obtains the proper number list (t i1 t i2 t i3 . . . t in ). The text proper number list is loaded in the memory 513 (FIG. 17). The microprocessor MPU 511 detects a physical address of each text according to a predetermined program (FIG. 20) in a microprogram memory 512. The text proper number and the physical address are managed by TEXT-DIR illustrated in FIG. 9, and the table can be read out of the file 451 and thus detected.
The microprocessor 511 then reads each text data out of the file 451. A file control division 531 inputs text data (character string) thus read out successively to an FIFO (first-in-first-out) circuit 532. The microprocessor MPU 511 reads characters one by one out of FIFO 532 and verifies whether or not a predetermined partial character string is present according to the finite automaton (FIG. 18(b)) defined in the memory 513. A string matching result b list (FIG. 20) is returned to the memory 402 of the upper processor.
CPU 1 arranges text proper number lists with retrieval conditions coincident with each other which are sent back from a plurality of lower FSM's into one according to a predetermined program and transmits them further to the memory 102 in the upper control subsystem. A document proper number DOC# with partial character strings matched therefor and a proper number of a document image IMGID or a title TITLE can be identified from the text proper number by referring to the main directory 153 (FIG. 5).
The retrieval results are sent back to the terminal 800. Users are capable of calling the image of a desired document to a CRT to display thereon while observing the title and others on the CRT.
A second illustrative example will be described, next. In the example, a configuration of the flexible string matching circuit 501 only is different. FIG. 21 is a configuration drawing of the flexible string matching circuit FSM in the second example.
In the drawing, a secondary storage unit (text file) 461 has a plurality of heads capable of reading a signal simultaneously, and in the example, data can be read out of the four heads simultaneously. The data is transmitted to four FIFO circuits 551 to 554 each by way of a file control unit FCU 541.
On the other hand, retrieval conditions sent from the upper subsystem 400 are interpreted by the microprocessor 551 and then transmitted to microprocessor units MPU 1 561 to MPU 4 564 including data memories.
Text data read out of the text file 461 are read to the microprocessor units 561 to 564 each by way of FIFO circuits 551 to 554. The microprocessor units search in parallel a predetermined partial character string from among four character strings (text data) and sends the result back to the microprocessor 511 by way of a data bus 521.
Since the other portions are equal to those of the first example, a description will be omitted.
A third illustrative example will be then taken up for description. In the example, the hardware configuration is the same as those of the first and second examples, but the text searching is different.
In taking up the case where a document to be retrieved is narrowed down by means of a keyword or classification code according to a hierarchical retrieval method, the document screened in the process is generally unevenly distributed to a volume of the text file.
In the system of the example, a text data is stored redundantly in a plurality of text file volumes for multiplicity. According to a predetermined program, CPU 401 (FIG. 4) selects a volume to access so as to even the frequency of access to a plurality of volumes for the texts stored redundantly in the volumes. According to the system, all the flexible string matching circuits operate efficiently, and a high-speed retrieval can be realized as a whole.
In the above example, a multiplicity of the flexible string search circuit is 3 or 4, however, the multiplicity is not particularly limited in the system according to the invention.
Then, the text search is carried out of the whole document uniformly and so described hereinabove, however, information on the page boundary will be recorded in the text in a special symbol, and a page number successful in string matching can also be output as a matching result, the system of which is also included in the invention.
Further, the description has been given on an English text, however, the system can also be applied likewise to other languages.
Then, the text data is extracted through character recognition in the above example, however, the mode of a text content retrieval is apparently applicable to a text data inputted by hand, which is included in the invention.
Further, a system status has been described as illustrated in FIG. 4, however, it remains unchanged substantially in the case of miniature system or stand-alone system, which is also included in the invention. In particular, it is conceivable that a text file and an image file provided in another system be loaded to a small scale retrieval station, which is included in the invention.
Still further, it goes without saying that retrieval conditions can be combined through a logical operator or extended so as to retrieve the partial character string satisfying a relative positional relation. Particularly, a combinative high retrieval can be realized at high speed through postprocessing by outputting a presence of each of a plurality of partial character strings.
As described above, according to the system of the invention, a desired document can be retrieved at high speed by referring to the contents of the document text, and also retrieved efficiently from a conception which is not conceivable at the point in time of having registered the document. Particularly at the time of registration, there is no necessity for worrying excessively about what is suitable to put as a classification code or keyword. A retrieval precision can be enhanced consequently and a noise occurrence can be suppressed at the same time.
Further, a text can be retrieved at high speed by juxtaposing the text search subsystem internally. A high speed operation can be attained particularly by adding a string matching circuit at every reading heads.
In the case of a retrieval for a large scale document file, the text contents can be retrieved by decreasing documents to be retrieved according to a keyword and bibliographical items, thus realizing an efficient retrieval as a whole.
Then, for obtaining a text data from document images, a document recognition result must have been inspected in each occasion to correct errors in the prior art, however, no attendant is particularly required therefor according to the invention. The text content retrieval has not been substantially realized hitherto for the reason mentioned above, but an effective text content retrieval can be secured by the invention.
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A document storage and retrieval system for storing a document body in the form of image, means for storing text information in the form of a character code string for retrieval, apparatus for executing a retrieval with reference to the text information, and apparatus for displaying a document image relating thereto on a retrieval terminal according to the retrieval result. Such a form of the system is available for retrieving the full contents of a document and also for displaying the document body printed in a format easy to read straight in the form of image. Users are capable of retrieving documents with arbitrary words and also capable of reading even such a document as is complicated to include mathematical expressions and charts through a terminal in the form of image, the same as on paper. A system is provided wherein the text information for retrieval is extracted automatically from the document image through character recognition. Since a precision of the character recognition has not been satisfactory hitherto, a visual retrieval and correction have been carried out without fail by operators. However, there is no necessity for the operators to attend therefor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of U.S. patent application Ser. No. 11/524,113 filed Sep. 20, 2006, which application claims the benefit of U.S. Provisional Application Nos. 60/825,517, filed Sep. 13, 2006, 60/824,357, filed Sep. 1, 2006, 60/823,332, filed on Aug. 23, 2006, 60/821,008, filed Aug. 1, 2006 and 60/798,568, filed on May 8, 2006 and is a continuation-in-part of U.S. patent application Ser. No. 11/252,010 filed on Oct. 17, 2005, which is a continuation of U.S. patent application Ser. No. 10/691,237 filed on Oct. 22, 2003. The disclosure of the above application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to transistor structures, and more particularly to transistor structures with reduced chip area.
BACKGROUND OF THE INVENTION
Integrated circuits or chips may include a large number of interconnected transistors. The transistors and other circuit elements are interconnected in various ways to provide desired circuit functions. It is usually most efficient to fabricate multiple integrated circuits on a single wafer. After processing, the integrated circuits that are fabricated on the wafer are separated and then packaged. The wafer can accommodate a fixed number of integrated circuits for a given integrated circuit size. Reducing the size of individual transistors in the integrated circuit may help to reduce the overall size of the integrated circuit. This, in turn, allows an increased number of integrated circuits or chips to be made on each wafer and reduces the cost of the integrated circuits.
Referring now to FIGS. 1 and 2 , an exemplary transistor 10 includes a drain 12 , a gate 14 , a source 16 and a body 18 or substrate tap. For example, the transistor 10 in FIG. 1 is an NMOS transistor. In some circumstances, the body 18 is connected to the source 16 as shown in FIG. 2 .
Referring now to FIG. 3 , the body 18 includes a p + region and may include a contact tap 30 . The source 16 includes an n + region and may include a contact tap 32 . The drain 12 includes an n + region and may include a contact tap 34 . Additional transistors may be fabricated on one or sides of the transistor 10 as indicated by “ . . . ” in FIG. 3 .
Referring now to FIG. 4 , the body 18 may be repeated between sources 16 of adjacent transistors. The body 18 takes up valuable chip area and increases the size of the transistor and the integrated circuit. Additional transistors can be arranged on one or more sides of the transistor 10 as shown by “ . . . ” in FIG. 4 .
SUMMARY OF THE INVENTION
An integrated circuit comprises a first source, a first drain, a second source, a first gate arranged between the first source and the first drain, and a second gate arranged between the first drain and the second source. The first and second gates define alternating first and second regions in the drain. The first and second gates are arranged farther apart in the first regions than in the second regions.
In other features, a well substrate contact is arranged in the first regions. Alternatively, R well substrate contacts are arranged in the first regions, where R is an integer greater than one. R is an integer that is greater than three and less than seven. The integrated circuit includes a plurality of transistors. The transistors include PMOS transistors. The R well substrate contacts are associated with respective ones of R transistors.
In other features, the integrated circuit comprises a second drain; and a third gate arranged between the second source and the second drain. The second and third gates define alternating third and fourth regions. The second and third gates are arranged farther apart in the third regions than in the fourth regions.
In yet other features, the first regions are arranged adjacent to the fourth regions and the second regions are arranged adjacent to the third regions. The first and third regions include R well substrate contacts.
A method for providing an integrated circuit comprises providing a first source; providing a first drain; providing a second source; locating a first gate between the first source and the first drain; locating a second gate between the first drain and the second source; defining alternating first and second regions in the drain using the first and second gates; and arranging the first and second gates farther apart in the first regions as compared to the second regions.
In other features, the method includes locating a well substrate contact in the first regions. The method includes locating R well substrate contacts in the first regions, where R is an integer greater than one. R is an integer that is greater than three and less than seven. The integrated circuit includes a plurality of transistors. The transistors include PMOS transistors. The method includes associating the R well substrate contacts with respective ones of R transistors.
In other features, the method includes providing a second drain; providing a third gate between the second source and the second drain; defining alternating third and fourth regions using the second and third gates; and arranging the second and third gates are arranged farther apart in the third regions than in the fourth regions.
In other features, the method includes arranging the first regions adjacent to the fourth regions and the second regions adjacent to the third regions. The first and third regions include R well substrate contacts, where R is an integer greater than one.
An integrated circuit comprises a first drain region having a generally rectangular shape. First, second, third and fourth source regions have a generally rectangular shape and are arranged adjacent to sides of the first drain region. A gate region is arranged between the first, second, third and fourth source regions and the first drain region. First, second, third and fourth substrate contact regions are arranged adjacent to corners of the first drain region.
In other features, the first, second, third and fourth source regions have a length that is substantially equal to a length of the drain region. The first, second, third and fourth source regions have a width that is less than a width of the first drain region. The width of the first, second, third and fourth source regions is approximately one-half the width of the first drain region.
In other features, a second drain region has a generally rectangular shape and has one side that is arranged adjacent to the first source region. Fifth, sixth and seventh source regions have a generally rectangular shape. The fifth, sixth and seventh source regions are arranged adjacent to other sides of the second drain region.
In other features, a gate region is arranged between the first, fifth, sixth and seventh source regions and the second drain region. Fifth and sixth substrate contact regions are arranged adjacent to corners of the second drain region. The integrated circuit includes laterally-diffused MOSFET transistors.
A method for providing an integrated circuit comprises providing a first drain region having a generally rectangular shape; arranging sides of first, second, third and fourth source regions, which have a generally rectangular shape, adjacent to sides of the first drain region; arranging a gate region between the first, second, third and fourth source regions and the first drain region; and arranging first, second, third and fourth substrate contact regions adjacent to corners of the first drain region.
In other features, the first, second, third and fourth source regions have a length that is substantially equal to a length of the drain region. The first, second, third and fourth source regions have a width that is less than a width of the first drain region. The width of the first, second, third and fourth source regions is approximately one-half the width of the first drain region.
In other features, the method includes arranging one side of a second drain region, which has a generally rectangular shape, adjacent to the first source region; and arranging fifth, sixth and seventh source regions, which have a generally rectangular shape, adjacent to other sides of the second drain region. The method includes arranging a gate region between the first, fifth, sixth and seventh source regions and the second drain region. The method includes arranging fifth and sixth substrate contact regions adjacent to corners of the second drain region. The integrated circuit includes laterally-diffused MOSFET transistors.
An integrated circuit comprises a first drain region having a symmetric shape across at least one of horizontal and vertical centerlines. A first gate region has a first shape that surrounds the first drain region. A second drain region has the symmetric shape. A second gate region has the first shape that surrounds the second drain region. A connecting gate region connects the first and second gate regions. A first source region is arranged adjacent to and on one side of the first gate region, the second gate region and the connecting gate region. A second source region is arranged adjacent to and on one side of side of the first gate region, the second gate region and the connecting gate region.
In other features, the symmetric shape tapers as a distance from a center of the symmetric shape increases. First and second substrate contacts are arranged in the first and second source regions. The integrated circuit includes laterally-diffused MOSFET transistors.
In other features, the symmetric shape is a circular shape. The symmetric shape is an elliptical shape. The symmetric shape is a polygonal shape. The symmetric shape is a hexagonal shape.
A method for providing an integrated circuit comprises providing a first drain region having a symmetric shape across at least one of horizontal and vertical centerlines; providing a first gate region having a first shape that surrounds the first drain region; providing a second drain region having the symmetric shape; providing a second gate region having the first shape that surrounds the second drain region; connecting a connecting gate region to the first and second gate regions; arranging a first source region adjacent to and on one side of the first gate region, the second gate region and the connecting gate region; and arranging a second source region adjacent to and on one side of side of the first gate region, the second gate region and the connecting gate region.
In other features, the symmetric shape tapers as a distance from a center of the symmetric shape increases. In other features, the method includes arranging first and second substrate contacts in the first and second source regions. The integrated circuit includes laterally-diffused MOSFET transistors.
In other features, the symmetric shape is a circular shape. The symmetric shape is an elliptical shape. The symmetric shape is a polygonal shape. The symmetric shape is a hexagonal shape.
An integrated circuit comprises first and second drain regions having a generally rectangular shape. First, second and third source regions that have a generally rectangular shape, wherein the first source region is arranged between first sides of the first and second drain regions and the second and third source regions are arranged adjacent to second sides of the first and second drain regions. A fourth source region is arranged adjacent to third sides of the first and second drain regions. A fifth source region is arranged adjacent to fourth sides of the first and second drain regions. A gate region is arranged between the first, second, third, fourth and fifth source regions and the first and second drain regions. First and second drain contacts are arranged in the first and second drain regions.
A method for providing an integrated circuit comprises providing first and second drain regions having a generally rectangular shape; arranging a first source region between first sides of the first and second drain regions; arranging second and third source regions adjacent to second sides of the first and second drain regions; arranging a fourth source region adjacent to third sides of the first and second drain regions; arranging a fifth source region adjacent to fourth sides of the first and second drain regions; arranging a gate region between the first, second, third, fourth and fifth source regions and the first and second drain region; and arranging first and second drain contacts in the first and second drain regions.
In other features of the integrated circuit and method, the first, second and third source regions have a length that is substantially equal to a length of the first drain region and wherein the fourth and fifth source regions have a length that is greater than or equal to a length of the first and second drain regions. The first, second and third source regions have a width that is less than a width of the first drain region. The width of the first, second and third source regions is approximately one-half the width of the first drain region. The fourth and fifth source regions are driven from sides thereof. The first and second drain contacts have a size that is greater than a minimum drain contact size. The drain contacts have one of a regular shape and an irregular shape. The drain contacts are one of square, rectangular, and cross-shaped. The first, second and third source regions include source contacts. The first and second drain regions and the firs, second and third source regions are arranged in a first row and further comprising N additional rows, wherein drain regions of at least one of the N additional rows share one of the fourth and fifth source regions.
An integrated circuit comprises first and second drain regions having a generally rectangular shape. First, second and third source regions that have a generally rectangular shape, wherein the first source region is arranged between first sides of the first and second drain regions and the second and third source regions are arranged adjacent to second sides of the first and second drain regions. A fourth source region is arranged adjacent to third sides of the first and second drain regions. A fifth source region is arranged adjacent to fourth sides of the first and second drain regions. A gate region is arranged between the first, second, third, fourth and fifth source regions and the first and second drain regions. First and second drain contacts are arranged in the first and second drain regions.
A method for providing an integrated circuit comprises providing first and second drain regions having a generally rectangular shape; arranging a first source region between first sides of the first and second drain regions; arranging second and third source regions adjacent to second sides of the first and second drain regions; arranging a fourth source region adjacent to third sides of the first and second drain regions; arranging a fifth source region adjacent to fourth sides of the first and second drain regions; arranging a gate region between the first, second, third, fourth and fifth source regions and the first and second drain region; and arranging first and second drain contacts in the first and second drain regions.
In other features of the integrated circuit and method, the first, second and third source regions have a length that is substantially equal to a length of the first drain region and wherein the fourth and fifth source regions have a length that is greater than or equal to a length of the first and second drain regions. The first, second and third source regions have a width that is less than a width of the first drain region. The width of the first, second and third source regions is approximately one-half the width of the first drain region. The fourth and fifth source regions are driven from sides thereof. The first and second drain contacts have a size that is greater than a minimum drain contact size. The drain contacts have one of a regular shape and an irregular shape. The drain contacts are one of square, rectangular, and cross-shaped. The first, second and third source regions include source contacts. The first and second drain regions and the firs, second and third source regions are arranged in a first row and further comprising N additional rows, wherein drain regions of at least one of the N additional rows share one of the fourth and fifth source regions.
Further regions 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
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is an electrical symbol for a transistor with a drain, source, gate and body according to the prior art;
FIG. 2 is an electrical symbol for a transistor with a drain, source, gate and body, which is connected to the source according to the prior art;
FIG. 3 is an exemplary layout of the transistor of FIG. 2 according to the prior art;
FIG. 4 is an exemplary layout of multiple transistors that are arranged in a row according to the prior art;
FIG. 5A is a first exemplary layout of transistors including a body that is arranged in the source;
FIG. 5B is a second exemplary layout of transistors including a body having edges that align with the gates in plan view;
FIG. 6 is a second exemplary layout of transistors including a body that is arranged in the source;
FIG. 7 is a third exemplary layout of transistors including a body that is arranged in the source;
FIG. 8 is a fourth exemplary layout of transistors including a body that is arranged in the source;
FIG. 9 is a fifth exemplary layout of transistors including a body that is arranged in the source;
FIG. 10 is a cross-sectional view of a PMOS transistor according to the prior art;
FIG. 11 is a plan view of a sixth exemplary layout including well substrate contacts;
FIG. 12A is a plan view of a seventh exemplary layout for reducing R DSon ;
FIG. 12B is a plan view of the seventh exemplary layout of FIG. 12A ;
FIG. 12C is a plan view of an eighth exemplary layout for reducing R DSon ;
FIG. 12D is a plan view of a ninth exemplary layout for reducing R DSon that is similar to FIG. 12C ;
FIG. 12E is a plan view of a tenth exemplary layout for reducing R DSon that is similar to FIG. 12C ;
FIGS. 12F-12I illustrate other exemplary drain contacts;
FIG. 13 is a plan view of a eleventh exemplary layout for reducing R DSon ; and;
FIG. 14 is a plan view of a twelfth exemplary layout for reducing R DSon ;
FIG. 15 is a plan view of a thirteenth exemplary layout for reducing R DSon ;
FIG. 16A is a functional block diagram of a hard disk drive;
FIG. 16B is a functional block diagram of a DVD drive;
FIG. 16C is a functional block diagram of a high definition television;
FIG. 16D is a functional block diagram of a vehicle control system;
FIG. 16E is a functional block diagram of a cellular phone;
FIG. 16F is a functional block diagram of a set top box; and
FIG. 16G is a functional block diagram of a media player.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify the same elements. Additional transistors can be arranged on one or more sides of the illustrated transistors that are shown in the FIGS. as indicated by “ . . . ” in the FIGS.
Referring now to FIGS. 5A and 5B , a transistor 50 according to the present invention is shown to include one or more sources 54 and one or more drains 56 . The sources 54 and the drains 56 include n + regions. While an NMOS transistor is shown, skilled artisans will appreciate that the present invention also applies to other types of transistors such as PMOS transistors. Gates 58 are located between adjacent pairs of sources 54 and drains 56 . In one implementation, the gates 58 that are located on opposite sides of the sources 54 are connected together as shown at 64 . In other configurations, however, the gates 58 need not be connected together.
A body 66 including a p + region is arranged inside of and is surrounded by the source 54 . The body 66 preferably has a shape that tapers as a distance between a midportion of the body 66 and adjacent gates decreases. The body 66 may touch or not touch the gates 58 in the plan views of FIGS. 5A and 5B . In other words, one or both edges of the body 66 may be spaced from the gates 58 in plan view (as shown in FIG. 5A ) and/or substantially aligns with the gates in plan view (as shown in FIG. 5B ). By utilizing some of the area of the source 54 for the body 66 , the overall size of the transistor 50 is reduced as compared to conventional transistors. In the exemplary implementation that is shown in FIG. 5 , the body 66 has a diamond shape.
Referring now to FIGS. 6 and 7 , other exemplary shapes for the body 66 are shown. In FIG. 6 , the body 66 has a hexagon shape. In FIG. 7 , the body is generally football shaped. Skilled artisans will appreciate that there are a wide variety of other suitable shapes. For example, a circular body is shown in FIG. 8 , which is described. Other suitable shapes include an ellipse, an octagon, etc.
Referring now to FIGS. 8 and 9 , the gates 58 can be arranged such that they are closer together when there are no contact taps and further apart when there are contact taps. In FIG. 8 , a source contact tap 70 , which is not located in the body 66 , is located in a region where the adjacent gates 58 are located farther apart. In FIG. 9 , a body contact tap 80 , which is located in the body 66 , is located in the source 54 where the adjacent gates 58 are located farther apart.
Referring now to FIG. 10 , a PMOS transistor 120 is shown. The transistor 120 includes a gate contact 122 , a source contact 126 , a drain contact 128 and a negative (N)-well contact 130 . The source contact 126 provides a connection to a P++ region 134 formed an N-type substrate layer 138 . The N-type layer 138 , in turn, is formed in a P-type substrate 140 . The P++ region 134 forms the source. The drain contact 128 provides an electrical connection to a P++ region 136 formed in the N-type layer 138 . The P++ region 136 forms the drain. The N-well contact 130 provides a connection to an N++ region 141 or N-well.
Referring now to FIG. 11 , a plan view of a sixth exemplary layout is shown. For some transistor designs such as PMOS and/or NMOS transistors, electrostatic discharge (ESD) is less important than other design criteria. Therefore, N-well contact areas can be minimized. For PMOS transistors, the N-well contact area may be approximately 2.5 to 3 times the area in NMOS transistors. The source-drain resistance may be less important. Therefore, the layout in FIG. 11 minimizes the N-well contact areas and the source-drain area. Skilled artisans will appreciate that while the foregoing description relates to PMOS transistors, similar principles apply to NMOS transistors.
In a layout shown in FIG. 11 , gate regions 200 - 1 , 200 - 2 , . . . , and 200 -G (collectively gate regions or gates 200 ) are defined between source regions 224 - 1 , 224 - 2 , . . . , and 224 -S (collectively source regions 224 ) and drain regions 220 - 1 , 220 - 2 , . . . , and 220 -D (collectively drain regions 220 ). Adjacent gates 200 - 1 and 200 - 2 define regions 210 having a wider width than adjacent regions 212 having narrower widths. Drain regions 220 and source regions 224 are alternately defined between the adjacent gates 200 .
Groups of transistors 230 - 11 , 230 - 12 , . . . , and 230 -XY (collectively groups of transistors 230 ) are arranged adjacent to each other. Adjacent groups of transistors 230 share R N-well contacts 260 , where R is an integer greater than one. The R N-well contacts 260 can be located between the adjacent groups of transistors 230 in regions 210 where the gates 200 are spaced further apart.
The source-drain area is minimized by this layout. For example, each group may include 4-6 transistors. The R N-well contacts 260 are provided for adjacent groups in both vertical and horizontal directions. Therefore, abutting edges of the adjacent groups without the R N-well contacts 260 can be located in regions 212 where the gates are spaced closer together. In other words, the gates 200 can be arranged closer together to minimize areas of the regions 212 without the R N-well contacts 260 .
Referring now to FIG. 12A , an exemplary high-density layout for laterally diffused MOSFET (LDMOS) transistors 300 is shown. The layout tends to reduce turn-on drain-source resistance R DSon . The transistors 300 include source (S) regions 304 , drain (D) regions 306 and gates 310 . Some, none or all of the source regions 304 may include one or more source contacts 311 . For illustration purposes, not all of the source regions 304 are shown with source contacts 311 .
The gates 310 define a checkerboard pattern. Source regions 304 are arranged along sides of the drain regions 306 . More particularly, the drain regions 306 may have a generally rectangular shape. The source regions 304 may be arranged along each side of the generally rectangular drain regions 306 . Substrate contacts 330 may be provided adjacent to corners of the drain regions 306 at intersections between adjacent source regions 304 . Drain contacts 334 may also be provided at a central location within the drain regions 306 .
Each drain region 306 may be arranged adjacent to source regions 304 that are common with other adjacent drain regions 306 . For example in dotted area 331 in FIG. 12A , drain region 306 - 1 shares the source region 304 - 1 with the drain region 306 - 2 . Drain region 306 - 1 shares the source region 304 - 2 with the drain region 306 - 3 . Drain region 306 - 1 shares the source region 304 - 3 with the drain region 306 - 4 . Drain region 306 - 1 shares the source region 304 - 4 with the drain region 306 - 5 . This pattern may be repeated for adjacent drain regions 306 .
Each of the drain regions 306 may have an area that is greater than or equal to two times the area of each of the source regions 304 . In FIG. 12A , the drain regions 306 have a width “b” and a height “a”. The source regions 304 have a width (or height) “d” and a height (or width) “c”. The drain regions 306 may have substantially the same length as the source regions 304 . The drain regions 306 may have greater than or equal to two times the width of the source regions 304 .
Referring now to FIG. 12B , a more detailed view of part of the layout of FIG. 12A is shown. Drain contacts 334 - 1 and 334 - 3 may be associated with drain regions 306 - 1 and 306 - 3 , respectively. Substrate contacts 330 are located adjacent to corners of the drain regions 306 - 1 . Source contacts 311 - 1 , 311 - 2 , . . . and 311 -B may be arranged in source regions 304 - 2 and 304 - 4 , where B is an integer. Drain contacts 334 - 1 and 334 - 3 may be arranged in each of the drain regions 306 - 1 and 306 - 3 , respectively. Drain contact 334 - 1 may define an area that is greater than the area of the source contact 311 - 1 in the source region 304 - 2 .
Substantially all of the current flowing between the drain region 306 - 3 and the source contacts 311 - 1 , 311 - 2 , . . . and 311 -B of the adjacent source region 304 - 2 flows between a facing portion 335 of the drain contact 334 - 3 and facing halves 337 - 1 , 337 - 2 , . . . and 337 -B of source contacts 311 - 1 , 311 - 2 , . . . and 311 -B in the source region 304 - 2 . Current flows in a similar manner between other facing portions of the drain contact 334 - 3 and source contacts (not shown) in other adjacent source regions 304 - 5 , 304 - 6 and 304 - 7 .
Referring now to FIG. 12C , another exemplary high-density layout for laterally diffused MOSFET (LDMOS) transistors 340 is shown. The layout tends to provide low turn-on drain-source resistance R DSon . The transistors 340 include source regions 304 - 11 , 304 - 12 , . . . 304 - 4 Q, drain regions 306 - 11 , 306 - 12 , . . . 306 - 4 T and gates 310 , where Q and T are integers. While four rows are shown in FIG. 12B , additional and/or fewer rows and/or columns may be employed. Some, none or all of the source regions 304 may include source contacts 311 . For illustration purposes, not all of the source regions 304 are shown with source contacts. For example, source region 304 - 12 includes source contacts 311 - 1 , 311 - 2 , . . . and 311 -B, where B is an integer.
Other elongated source regions 344 - 1 , 344 - 2 , 344 - 3 , . . . and 344 -R are arranged between rows (or columns) of drain regions 306 and may be driven by drivers 346 - 1 , 346 - 2 , . . . , and 346 -R arranged on one or both sides (or tops) of the layout in FIG. 12B . The elongated source regions 344 - 1 , 344 - 2 , 344 - 3 , . . . and 344 -R may extend adjacent to sides of at least two drain regions 306 such as at least drain regions 306 - 11 and 306 - 12 .
Each of the drain regions 306 (such as drain region 306 - 11 ) may have an area that is greater than or equal to two times the area of each of the source regions 304 (such as source region 304 - 12 ). The drain regions 306 (such as drain region 306 - 11 ) may have substantially the same length as the source regions 304 (such as source region 304 - 12 ). The drain regions 306 (such as drain region 306 - 11 ) may have greater than or equal to two times the width of the source regions 304 (such as source region 304 - 12 ).
Substrate contacts 347 - 11 , 347 - 12 , 347 - 21 , 347 - 22 , 347 - 23 , . . . 347 - 51 , 347 - 52 (collectively substrate contacts 347 ) may be arranged in some, none or all of the elongated source regions 344 . The placement and number of substrate contracts 347 may be uniform or varied for each of the elongated source regions 344 . For example only, the substrate contacts 347 shown in FIG. 12C may be offset from the substrate contacts 347 in adjacent elongated source regions 344 . Each of the elongated source regions 344 may include the same number or a different number of substrate contacts 347 than adjacent elongated source regions 344 . The substrate contacts 347 may be aligned or offset as shown. Some elongated source regions 344 may include no substrate contacts 347 . Still other variations are contemplated.
Referring now to FIG. 12D , first areas 345 -A 1 , 345 -A 2 , 345 -A 3 and 345 -A 4 may provide useful transistor areas. For example, first areas 345 -A 1 , 345 -A 2 , 345 -A 3 and 345 -A 4 may be located between drain region 306 - 12 and source regions 304 - 12 , 344 - 1 , 304 - 13 , and 344 - 2 , respectively. Second areas 345 -B 1 , 345 -B 2 , 345 -B 3 and 345 -B 4 may provide less useful transistor areas. For example, second areas 345 -B 1 , 345 -B 2 , 345 -B 3 and 345 -B 4 may be located between source regions 304 - 12 , 344 - 1 , 304 - 13 , and 344 - 2 .
In some implementations, the substrate contacts 347 - 11 , 347 - 12 , 347 - 21 , 347 - 22 , 347 - 23 , . . . may be arranged in some, none or all of the second areas 345 -B 1 , 345 -B 2 , 345 -B 3 and 345 -B 4 of the source regions 344 - 1 , 344 - 2 , . . . and 344 -R, for example as shown in FIG. 12D . The substrate contacts 347 - 11 , 347 - 12 , 347 - 21 , 347 - 22 , 347 - 23 , . . . are shown arranged in the elongated substrate regions 344 - 1 and 344 - 2 and tend to lower R DS — ON . The substrate contacts 347 - 11 , 347 - 12 , 347 - 21 , 347 - 22 , 347 - 23 , . . . may have a height that is less than or equal to a width “c” of the source regions 304 (as shown in FIG. 12A ) and a width that is less than or equal to a width “d” of the source regions 304 (as shown in FIG. 12A ).
Referring now to FIG. 12E , substrate contacts 330 - 1 and 330 - 2 are provided between pairs of elongated source regions 344 - 1 A and 344 - 1 B and 344 - 2 A and 344 - 2 B, respectively. The elongated source regions 344 - 1 A and 344 - 2 A are driven from one side by drivers 346 - 1 A and 346 - 2 A. The elongated source regions 344 - 1 B and 344 - 2 B are driven from another side by drivers 346 - 1 B and 346 - 2 B.
Drain contacts 334 in FIGS. 12A-12E may have a minimum size or a size that is greater than the minimum size. Drain contacts 334 may have a simple or regular shape and/or an irregular or complex shape. For example, the drain contacts 334 may have a square or rectangular shape (as shown at 344 in FIG. 12A ), a cross shape (as shown at 344 -W in FIG. 12F ), clover-leaf shapes (as shown at 334 -X and 334 -Y in FIGS. 12G and 12H , respectively), a modified cross-shaped region (as shown at 334 -Z in FIG. 12I ) and/or other suitable shapes such as but not limited to diamond, circular, symmetric, non-symmetric, etc. The substrate contacts 347 may similarly have a simple or regular shape and/or an irregular or complex shape similar to the drain contacts 334 .
In some implementations, the number of source contacts B in a given source region may be an integer that is greater than one and less than six. In some implementations, B may be equal to 3 or 4. The area of the drain contact 334 - 3 may be greater than or equal to 2*B* (the area one of source contacts 311 - 1 , 311 - 2 , . . . or 311 -B). For example, when B is equal to 3, the drain contact region 334 - 3 may have an area that is approximately greater than or equal to 6 times an area of one source contact 311 - 1 , 311 - 2 , . . . or 311 -B. When B is equal to 4, the drain contact region 334 - 3 may an area that is approximately greater than or equal to 8 times an area of one source contact 311 - 1 , 311 - 2 , . . . or 311 -B.
As the size of the drain contacts 334 increases relative to the corresponding drain region 306 , over-etching may occur. In other words, the etching process may adversely impact adjacent regions and/or underlying layers. To alleviate the problems of over-etching, the complex shapes in FIGS. 12F-12I and/or other complex shapes can be employed for the drain contacts 334 . Alternately, the drain contacts 334 can employ deep implant ions in and/or below the drain contacts 334 .
As an alternative to placing the substrate contact 330 in the elongated source regions 344 , a relief area may be provided in one or both sides of the source region 344 in areas 345 -B 1 , 345 -B 2 , 345 -B 3 and 345 -B 4 . A substrate contact region 330 can be positioned in the relief area. The shape of the elongate source region 344 can be adjusted on an opposite side of the relief area to offset the effect of the relief area and to prevent reduction in current density in areas of the elongate source region 344 near the relief areas.
Referring now to FIGS. 13-15 , drain, source and gate regions can also have other shapes that can be used to minimize R DSON . For example, drain regions 348 can have a circular shape as shown in FIG. 13 , an elliptical shape as shown in FIG. 14 and/or other suitable shapes. Gate regions 349 include circular-shaped gate regions 350 that are connected by linear gate connecting regions 352 . Similar elements are identified in FIG. 14 using a prime symbol (“′”). The drain regions 348 are located in the circular-shaped gate regions 350 . Source regions 360 are located in between the gate regions 349 in areas other than the inside of the circular shaped gate regions 350 . Substrate contacts 364 are located in the source regions 360 . The drain regions 348 may also include a contact region 366 . The linear gate regions 352 may have a vertical spacing “g” that is minimized to increase density. Likewise, lateral spacing identified at “f” between adjacent circular-shaped gate regions 350 may be minimized to increase density.
Drain areas 368 can also have polygon shapes. For example, the drain areas can have a hexagon shape as shown in FIG. 15 , although other polygon shapes can be used. Gate regions 369 include hexagon-shaped gate regions 370 that are connected by linear gate connecting regions 372 . The drain regions 368 are located in the hexagon-shaped gate regions 370 . Source regions 380 are located in between the gate regions 369 in areas other than the inside of the hexagon-shaped gate regions 370 . Substrate contacts 384 are located in the source regions 380 . The drain regions may also include a contact region 386 . The linear gate connecting regions 372 preferably have a vertical spacing “j” that is minimized to increase density. Likewise lateral spacing identified at “i” between adjacent hexagon-shaped gate regions 370 is minimized to increase density.
As can be appreciated, the shapes for the drain and gate areas in FIGS. 13-15 can be any shape that is symmetric about at least one of the horizontal and vertical centerlines of the drain areas. The transistors in FIGS. 13-15 may be LDMOS transistors. The shape of the drain regions may include any symmetric shape. The shape may taper as a distance from a center point of the drain area increases and/or as a center point of the drain area increases in a direction towards one or more other transistors.
Referring now to FIGS. 16A-16G , various exemplary implementations incorporating the teachings of the present disclosure are shown.
Referring now to FIG. 16A , the teachings of the disclosure can be implemented in a transistors of a hard disk drive (HDD) 400 . The HDD 400 includes a hard disk assembly (HDA) 401 and a HDD PCB 402 . The HDA 401 may include a magnetic medium 403 , such as one or more platters that store data, and a read/write device 404 . The read/write device 404 may be arranged on an actuator arm 405 and may read and write data on the magnetic medium 403 . Additionally, the HDA 401 includes a spindle motor 406 that rotates the magnetic medium 403 and a voice-coil motor (VCM) 407 that actuates the actuator arm 405 . A preamplifier device 408 amplifies signals generated by the read/write device 404 during read operations and provides signals to the read/write device 404 during write operations.
The HDD PCB 402 includes a read/write channel module (hereinafter, “read channel”) 409 , a hard disk controller (HDC) module 410 , a buffer 411 , nonvolatile memory 412 , a processor 413 , and a spindle/VCM driver module 414 . The read channel 409 processes data received from and transmitted to the preamplifier device 408 . The HDC module 410 controls components of the HDA 401 and communicates with an external device (not shown) via an I/O interface 415 . The external device may include a computer, a multimedia device, a mobile computing device, etc. The I/O interface 415 may include wireline and/or wireless communication links.
The HDC module 410 may receive data from the HDA 401 , the read channel 409 , the buffer 411 , nonvolatile memory 412 , the processor 413 , the spindle/VCM driver module 414 , and/or the I/O interface 415 . The processor 413 may process the data, including encoding, decoding, filtering, and/or formatting. The processed data may be output to the HDA 401 , the read channel 409 , the buffer 411 , nonvolatile memory 412 , the processor 413 , the spindle/VCM driver module 414 , and/or the I/O interface 415 .
The HDC module 410 may use the buffer 411 and/or nonvolatile memory 412 to store data related to the control and operation of the HDD 400 . The buffer 411 may include DRAM, SDRAM, etc. The nonvolatile memory 412 may include flash memory (including NAND and NOR flash memory), phase change memory, magnetic RAM, or multi-state memory, in which each memory cell has more than two states. The spindle/VCM driver module 414 controls the spindle motor 406 and the VCM 407 . The HDD PCB 402 includes a power supply 416 that provides power to the components of the HDD 400 .
Referring now to FIG. 16B , the teachings of the disclosure can be implemented in a transistors of a DVD drive 418 or of a CD drive (not shown). The DVD drive 418 includes a DVD PCB 419 and a DVD assembly (DVDA) 420 . The DVD PCB 419 includes a DVD control module 421 , a buffer 422 , nonvolatile memory 423 , a processor 424 , a spindle/FM (feed motor) driver module 425 , an analog front-end module 426 , a write strategy module 427 , and a DSP module 428 .
The DVD control module 421 controls components of the DVDA 420 and communicates with an external device (not shown) via an I/O interface 429 . The external device may include a computer, a multimedia device, a mobile computing device, etc. The I/O interface 429 may include wireline and/or wireless communication links.
The DVD control module 421 may receive data from the buffer 422 , nonvolatile memory 423 , the processor 424 , the spindle/FM driver module 425 , the analog front-end module 426 , the write strategy module 427 , the DSP module 428 , and/or the I/O interface 429 . The processor 424 may process the data, including encoding, decoding, filtering, and/or formatting. The DSP module 428 performs signal processing, such as video and/or audio coding/decoding. The processed data may be output to the buffer 422 , nonvolatile memory 423 , the processor 424 , the spindle/FM driver module 425 , the analog front-end module 426 , the write strategy module 427 , the DSP module 428 , and/or the I/O interface 429 .
The DVD control module 421 may use the buffer 422 and/or nonvolatile memory 423 to store data related to the control and operation of the DVD drive 418 . The buffer 422 may include DRAM, SDRAM, etc. The nonvolatile memory 423 may include flash memory (including NAND and NOR flash memory), phase change memory, magnetic RAM, or multi-state memory, in which each memory cell has more than two states. The DVD PCB 419 includes a power supply 430 that provides power to the components of the DVD drive 418 .
The DVDA 420 may include a preamplifier device 431 , a laser driver 432 , and an optical device 433 , which may be an optical read/write (ORW) device or an optical read-only (OR) device. A spindle motor 434 rotates an optical storage medium 435 , and a feed motor 436 actuates the optical device 433 relative to the optical storage medium 435 .
When reading data from the optical storage medium 435 , the laser driver provides a read power to the optical device 433 . The optical device 433 detects data from the optical storage medium 435 , and transmits the data to the preamplifier device 431 . The analog front-end module 426 receives data from the preamplifier device 431 and performs such functions as filtering and A/D conversion. To write to the optical storage medium 435 , the write strategy module 427 transmits power level and timing information to the laser driver 432 . The laser driver 432 controls the optical device 433 to write data to the optical storage medium 435 .
Referring now to FIG. 16C , the teachings of the disclosure can be implemented in a transistors of a high definition television (HDTV) 437 . The HDTV 437 includes a HDTV control module 438 , a display 439 , a power supply 440 , memory 441 , a storage device 442 , a WLAN interface 443 and associated antenna 444 , and an external interface 445 .
The HDTV 437 can receive input signals from the WLAN interface 443 and/or the external interface 445 , which sends and receives information via cable, broadband Internet, and/or satellite. The HDTV control module 438 may process the input signals, including encoding, decoding, filtering, and/or formatting, and generate output signals. The output signals may be communicated to one or more of the display 439 , memory 441 , the storage device 442 , the WLAN interface 443 , and the external interface 445 .
Memory 441 may include random access memory (RAM) and/or nonvolatile memory such as flash memory, phase change memory, or multi-state memory, in which each memory cell has more than two states. The storage device 442 may include an optical storage drive, such as a DVD drive, and/or a hard disk drive (HDD). The HDTV control module 438 communicates externally via the WLAN interface 443 and/or the external interface 445 . The power supply 440 provides power to the components of the HDTV 437 .
Referring now to FIG. 16D , the teachings of the disclosure may be implemented in a transistors of a vehicle 446 . The vehicle 446 may include a vehicle control system 447 , a power supply 448 , memory 449 , a storage device 450 , and a WLAN interface 452 and associated antenna 453 . The vehicle control system 447 may be a powertrain control system, a body control system, an entertainment control system, an anti-lock braking system (ABS), a navigation system, a telematics system, a lane departure system, an adaptive cruise control system, etc.
The vehicle control system 447 may communicate with one or more sensors 454 and generate one or more output signals 456 . The sensors 454 may include temperature sensors, acceleration sensors, pressure sensors, rotational sensors, airflow sensors, etc. The output signals 456 may control engine operating parameters, transmission operating parameters, suspension parameters, etc.
The power supply 448 provides power to the components of the vehicle 446 . The vehicle control system 447 may store data in memory 449 and/or the storage device 450 . Memory 449 may include random access memory (RAM) and/or nonvolatile memory such as flash memory, phase change memory, or multi-state memory, in which each memory cell has more than two states. The storage device 450 may include an optical storage drive, such as a DVD drive, and/or a hard disk drive (HDD). The vehicle control system 447 may communicate externally using the WLAN interface 452 .
Referring now to FIG. 16E , the teachings of the disclosure can be implemented in a transistors of a cellular phone 458 . The cellular phone 458 includes a phone control module 460 , a power supply 462 , memory 464 , a storage device 466 , and a cellular network interface 467 . The cellular phone 458 may include a WLAN interface 468 and associated antenna 469 , a microphone 470 , an audio output 472 such as a speaker and/or output jack, a display 474 , and a user input device 476 such as a keypad and/or pointing device.
The phone control module 460 may receive input signals from the cellular network interface 467 , the WLAN interface 468 , the microphone 470 , and/or the user input device 476 . The phone control module 460 may process signals, including encoding, decoding, filtering, and/or formatting, and generate output signals. The output signals may be communicated to one or more of memory 464 , the storage device 466 , the cellular network interface 467 , the WLAN interface 468 , and the audio output 472 .
Memory 464 may include random access memory (RAM) and/or nonvolatile memory such as flash memory, phase change memory, or multi-state memory, in which each memory cell has more than two states. The storage device 466 may include an optical storage drive, such as a DVD drive, and/or a hard disk drive (HDD). The power supply 462 provides power to the components of the cellular phone 458 .
Referring now to FIG. 16F , the teachings of the disclosure can be implemented in a transistors of a set top box 478 . The set top box 478 includes a set top control module 480 , a display 481 , a power supply 482 , memory 483 , a storage device 484 , and a WLAN interface 485 and associated antenna 486 .
The set top control module 480 may receive input signals from the WLAN interface 485 and an external interface 487 , which can send and receive information via cable, broadband Internet, and/or satellite. The set top control module 480 may process signals, including encoding, decoding, filtering, and/or formatting, and generate output signals. The output signals may include audio and/or video signals in standard and/or high definition formats. The output signals may be communicated to the WLAN interface 485 and/or to the display 481 . The display 481 may include a television, a projector, and/or a monitor.
The power supply 482 provides power to the components of the set top box 478 . Memory 483 may include random access memory (RAM) and/or nonvolatile memory such as flash memory, phase change memory, or multi-state memory, in which each memory cell has more than two states. The storage device 484 may include an optical storage drive, such as a DVD drive, and/or a hard disk drive (HDD).
Referring now to FIG. 16G , the teachings of the disclosure can be implemented in a transistors of a media player 489 . The media player 489 may include a media player control module 490 , a power supply 491 , memory 492 , a storage device 493 , a WLAN interface 494 and associated antenna 495 , and an external interface 499 .
The media player control module 490 may receive input signals from the WLAN interface 494 and/or the external interface 499 . The external interface 499 may include USB, infrared, and/or Ethernet. The input signals may include compressed audio and/or video, and may be compliant with the MP3 format. Additionally, the media player control module 490 may receive input from a user input 496 such as a keypad, touchpad, or individual buttons. The media player control module 490 may process input signals, including encoding, decoding, filtering, and/or formatting, and generate output signals.
The media player control module 490 may output audio signals to an audio output 497 and video signals to a display 498 . The audio output 497 may include a speaker and/or an output jack. The display 498 may present a graphical user interface, which may include menus, icons, etc. The power supply 491 provides power to the components of the media player 489 . Memory 492 may include random access memory (RAM) and/or nonvolatile memory such as flash memory, phase change memory, or multi-state memory, in which each memory cell has more than two states. The storage device 493 may include an optical storage drive, such as a DVD drive, and/or a hard disk drive (HDD).
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
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An integrated circuit comprises first and second drain regions have a generally rectangular shape. First, second and third source regions have a generally rectangular shape, wherein the first source region is arranged between first sides of the first and second drain regions and the second and third source regions are arranged adjacent to second sides of the first and second drain regions. Fourth and fifth source regions, wherein the fourth source region is arranged adjacent to third sides of the first and second drain regions and wherein the fifth source region is arranged adjacent to fourth sides of the first and second drain regions. A gate region is arranged between the first, second, third, fourth and fifth source regions and the first and second drain regions. First and second drain contacts that are arranged in the first and second drain regions.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus and method for use in non-invasively determining a condition of the circulatory system of a subject. More particularly, the present invention is directed to an apparatus and method for non-invasively determining the functional cardiac output of the heart.
The physiological function of the heart is to circulate blood through the circulatory system to the body and lungs. For this purpose, the heart receives blood in arterial chambers during its relaxed or diastolic phase and discharges blood from its ventricle chambers during the contractile or systolic phase. The amount of blood discharged from a ventricle chamber of the heart per unit time is the cardiac output (CO). A typical cardiac output for the heart of a normal adult (at rest) is 5-6 liters per minute.
During circulation through the body, the blood is depleted of oxygen (O 2 ) and is enriched with carbon dioxide (CO 2 ) as a result of the metabolic activity of the body. A major purpose for blood circulation is to take venous blood that has been depleted in O 2 and enriched in CO 2 as a result of its passage through the tissues of the body and supply it to the lungs. In the alveoli of the lungs, O 2 is supplied to the blood from the breathing gases, typically air, and CO 2 is discharged into the breathing gases. The oxygenated arterial blood is then supplied to the body tissues. The gas exchange takes place in the capillaries of the lung because of the differences in concentration, or partial pressure, of O 2 and CO 2 in breathing gases, such as air, and in the venous blood. That is, the blood is low in O 2 and high in CO 2 whereas air is high in O 2 and low in CO 2 .
A common condition reducing the gas exchange efficiency of the lungs is the presence of shunt perfusion or blood flow in the lungs. A shunt comprises pulmonary blood flow that does not engage in gas exchange with breathing gases, due to blockage or constriction in alveolar gas passages, or for other reasons. This shunt blood flow thus bypasses normal alveoli in which gas exchange is carried out. Upon leaving the lungs, the shunt blood flow mixes with the non-shunt blood flow. The former reduces the oxygen content and increases the CO 2 content in the mixed arterial blood supplied to the body tissues.
It will be appreciated that only the non-shunt pulmonary blood flow through the lungs participates in the gas exchange function of the lungs and in oxygenation and CO 2 removal in the blood of the subject. The quantity of blood that participates in such pulmonary gas exchange in the lungs is termed functional cardiac output (FCO). For diagnostic or other purposes, it is frequently desirable or essential to know this quantity.
While shunt conditions can occur in the lungs due to blockage brought about by disease, mechanical ventilation, particularly when the respiratory muscles of a subject are relaxed as during anesthesia, can result in an increase in the pulmonary shunt. The breathing gases supplied to the lungs can be enriched with oxygen under such conditions to assist in oxygenation of the blood. However, a sufficient amount of CO 2 may not be removed from the blood when the pulmonary shunt is increased, giving rise to potentially adverse consequences to the subject.
The classic technique for determining the functional cardiac output of the heart is through use of the Fick equation
FCO = VCO 2 CvCO 2 - CcCO 2 ( 1 )
where,
VCO 2 in ml/min. is the amount of CO2 released from the blood in the circulatory system of the subject, CvCO 2 is the mixed venous blood CO 2 content, for example in ml CO 2 /ml of blood, and CcCO 2 is the end capillary blood CO 2 content, i.e. the CO 2 content in the blood leaving the ventilated lungs.
The Fick equation states that, knowing the amount of CO 2 gas released from the blood in a unit of time (e.g. the rate of gas transfer as a volume/minute) and the concurrent gas transfer occurring per unit of blood (i.e. volume of gas/volume of blood), the blood flow through the lungs (i.e. FCO expressed in volume/minute) can be determined.
If a portion of the pulmonary blood flow of the subject is in shunt, this will decrease the amount of CO 2 released from the blood and the computation of Equation (1) provides an indication of the resulting decrease in functional cardiac output. In computing functional cardiac output using the Fick equation, the quantity VCO 2 can be determined non-invasively by subtracting the amount of CO 2 of the inhaled breathing gases, for example air, from the amount of CO 2 of the exhaled breathing gases, taking into account changes in the amount of CO 2 stored in the lungs and the deadspace in the breathing organs of the subject, such as the trachea and bronchi. The amount of CO 2 stored in the lungs can be computed from the alveolar CO 2 gas concentration, as determined from an end tidal breathing gas measurement, and the end expiratory volume V EE of the lungs. The end capillary blood CO 2 content (CcCO 2 ) can be determined non-invasively, with a fair degree of accuracy, from a measurement of the concentration of CO 2 in the breathing gases exhaled at the end of the expiration of a tidal breathing gas volume, i.e. the end tidal (ET) CO 2 level. See also Respiratory Physiology, by J. F. Nunn, published 1993 by Butterworths.
The venous blood CO 2 content (CvCO 2 ), is often determined invasively. An alternate non-invasive approach for the determination of the CvCO 2 can be seen in U.S. Pat. No. 6,042,550 and WO 01/62148. In these approaches, exhaled CO 2 enriched breathing gases are rebreathed by the subject in subsequent inhalations. As rebreathing of the exhaled breathings gases continues, breath-by-breath, the end tidal CO 2 partial pressure (P ET CO 2 ) increases until the end capillary blood CO 2 partial pressure (P c CO 2 ) is reached. At this point, it is postulated that the end tidal CO 2 partial pressure (P ET CO 2 ), the alveolar CO 2 partial pressure (P A CO 2 ), the end capillary blood CO 2 partial pressure (P c CO 2 ), and the venous blood CO 2 partial pressure (P v CO 2 ) are all equal and that this partial pressure can be converted to the venous CO 2 content (C v CO 2 ) for use in the Fick equation.
The need for the determination of the venous blood CO 2 content (C v CO 2 ) is eliminated by the use of a differential form of the Fick equation which arises from the following circumstances. As a subject rebreathes exhaled breathing gases, the end tidal CO 2 partial pressure (P ET CO 2 ) and thus the alveolar CO 2 partial pressure (P A CO 2 ) and end capillary CO 2 content increases. This reduces the venous blood-alveolar CO 2 partial pressure differences and because this is the driving force for CO 2 elimination in the lungs, CO 2 elimination is also reduced. It has been shown that the ratio of the change in CO 2 elimination to the change in the end capillary blood CO 2 content is equal to the functional cardiac output. See Gedeon A., et al. Med. Biol. Eng. Comp. 18:411-418 (1980). It is set forth in equation form, as follows:
FCO = VCO 2 N - VCO 2 R CcCO 2 R - CcCO 2 N = Δ VCO 2 Δ CcCO 2 ( 2 )
In the differential form of the Fick equation, the superscript N indicates values obtained in “normal” breathing conditions. The superscript R indicates values obtained during a short term “reduction” in the CO 2 partial pressure difference between that in the alveoli and that in the blood. This results in reduced CO 2 transfer in the lungs.
In using the differential form of the Fick equation, a first set of values for VCO 2 and CcCO 2 are obtained, as in the manner described above, under normal breathing conditions. These are identified by the superscript N. Thereafter, the amount of CO 2 in the breathing gases for the subject is increased. This maybe accomplished by a partial re-breathing of exhaled breathing gases. See U.S. Pat. Nos. 5,836,300 or 6,106,480 and published International Patent Appln. WO 98/26710 that employ valve mechanisms, to vary the re-breathed gas volume, for this purpose. Or, this may be accomplished by injecting CO 2 into the inhaled breathing gases as described in U.S. Pat. No. 4,608,995. Further possibilities for altering the alveolar CO 2 content include varying lung ventilation. This may be accomplished by altering the tidal volume or the respiration rate. Single breath maneuvers such as a deep breath as presented by Mitchell R R in Int J Clin Mon Comp 5:53-64 (1988), inspiratory hold as presented in WO 99/25244, or expiratory hold, may also be used for the purpose.
The CO 2 enrichment increases the concentration of CO 2 in the alveoli in the lungs and reduces the CO 2 partial pressure difference between that of the breathing gases in the lungs and that in the venous blood. As noted above, it is that CO 2 partial pressure difference that drives the CO 2 gas transfer from venous blood to the breathing gases in the alveoli of the lungs. The reduced CO 2 partial pressure difference reduces CO 2 gas transfer in the lung and causes an elevation of the CO 2 content in the blood downstream of the lung, i.e. in the arterial blood of the subject. In the time interval before the blood with elevated CO 2 content circulates through the body and returns to the lungs, the CO 2 content of venous blood (CvCO 2 ) entering the lungs can be taken to be the same for both the initial, normal breathing conditions (N) and the subsequent, reduced CO 2 partial pressure difference conditions labeled by the superscript R. This similitude permits the factor CvCO 2 to be dropped out of the Fick equation when expressed in the differential form as Equation 2 so that the cardiac output is determined by the ratio of the change in released CO 2 amounts (VCO 2 ) between the normal (N) and reduced (R) gas exchange conditions to the corresponding change in the end capillary blood CO 2 content (CcCO 2 ) in the normal and reduced (R) gas exchange conditions. The need to determine the venous blood CO 2 content (CvCO 2 ) from the subject is thus eliminated.
The foregoing approach is also advantageous with ventilated or anesthetized subjects since the alteration of the CO 2 content of the breathing gases can be effected by altering the ventilation provided to the subject. In the case of a subject anesthetized with a breathing circuit of the recirculating type, the alteration in CO 2 content may be carried out by bypassing the CO 2 absorber in the breathing circuit. The CO 2 absorber removes CO 2 from exhaled breathing gases of the subject thereby allowing the breathing gases to be recirculated to form inspiratory breathing gases for the subject. Bypassing the absorber increases the amount of CO 2 in the breathing gases that are recirculated to the subject for inspiration.
While the above described techniques avoid the need to invasively determine venous blood CO 2 content, other problems are created. In cases in which a subject is being provided with a fixed volume of breathing gases, an increased re-breathing volume is accompanied by a decreased volume of inspired oxygen. This may produce an undesired reduction in the oxygen content in the blood or require increased oxygen concentrations in the inspired breathing gases, following a cardiac output measurement, to restore oxygen levels in the blood to desired values. Also the tubing required for the large re-breathing volume adds to the size of associated valve systems making them big and bulky when assembled at the very crowded area near the mouth and nose of the subject. Such apparatus also adds to the overall ventilation dead-space volume between the breathing circuit for the subject and the subjects lungs. This increases the amount of ventilation required, adding to the risk of lung distension.
The injection of carbon dioxide into inspired breathing gas overcomes the problems of reduced oxygenation and bulky valve systems, but raises analogous problems. The CO 2 is obtained from a gas source and is typically injected using a gas tube. Such a tube is not normally present at the point of care for the subject and adding such a tube, with the accompanying high-pressure regulators and supply conduits, into the already crowded care environment is also undesirable.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved apparatus and method for carrying out an alteration in the CO 2 content of breathing gases inspired by a subject for purposes of non-invasively determining a circulatory system condition, e.g. the functional cardiac output, of a subject.
Another object of the present invention is to provide an apparatus and method that can carry out such alteration without affecting the exchange of other respiratory gases, such as oxygen, in the lung.
Yet another object of the present invention is to provide such apparatus that minimizes disturbance to a patient care environment and minimizes the overall increase in the breathing circuit-lung dead-space volume.
Briefly, in accordance with the improved apparatus and method of the present invention for altering the CO 2 content of the breathing gases, and the lung CO 2 partial pressure, the breathing gas flow is selectively guided through a CO 2 exchanger in a flow path for the breathing gases. The CO 2 exchanger selectively takes up CO 2 from the expired breathing gases of the subject and releases it to the breathing gases inhaled in a subsequent inspiration. Such an exchanger can be made of a gas porous element, for example, activated charcoal or zeolite, with pore sizes suitable for the adsorption CO 2 .
The CO 2 exchanger can be in a form of a moveable element, that can, with the aid of a transfer mechanism, be moved into and out a flow path of the breathing gases. Alternatively, especially during prolonged artificial ventilation of a subject in intensive care, when the dry inspiration breathing gas is often humidified and warmed with a heat and moisture exchanger (HME), the CO 2 exchanger can be connected in parallel with such an HME. Using a control valve, the breathing gas flow can be directed either through the HME, thereby forming a CO 2 exchanger bypass channel, or through the CO 2 exchanger. With such an arrangement, an increase of the dead space in the breathing gases pathway is avoided. The temporary interruption of the humidification when the breathing gas is directed through the CO 2 exchanger is easily tolerated by the subject. To keep the gas exchange conditions unchanged gases other than CO 2 , the volume of the CO 2 exchanger and associated components is advantageously equal to the volume of the by-pass channel containing the HME.
Breathing gas measurements obtained when the breathing gases are not passing through the exchanger and when they are passing through the exchanger may be used to determine the functional cardiac output of the subject using the differential Fick equation, in the manner described above.
Various other features, objects, and advantages of the invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
In the drawing:
FIG. 1 is a graph showing data obtained from the breathing gases of a subject under normal breathing conditions and under conditions of reduced gas exchange in the lungs of the subject;
FIG. 2 shows a breathing device using the apparatus of the present invention in order to determine functional cardiac output;
FIG. 3 a is a detailed cross sectional view of the apparatus according to the present invention showing a moveable CO 2 exchanger element in a position in which the breathing gases of the subject bypass the CO 2 exchanger element;
FIG. 3 b is a similar view showing the CO 2 exchanger element transferred to a position in which it is in the breathing gas flow path;
FIG. 4 is a graph of the breathing gas CO 2 concentration when the breathing gas is passed through the CO 2 exchanger element and when it by-passes the exchanger element; and
FIG. 5 is an alternative embodiment of the CO 2 exchanger apparatus of the present invention connected in parallel to a heat and moisture exchanger.
DETAILED DESCRIPTION OF THE INVENTION
The basic principles of the analytical technique in which the apparatus and method of the present invention find use are as follows. For one or more normal (N) breaths of the subject, values are obtained for the amount of CO 2 released from the blood (VCO 2 N ) and for a quantity indicative of the end capillary blood CO 2 content, for example CcCO 2 N . One or more values for the same quantities are obtained under conditions of reduced (R) gas exchange in the lungs of the subject, to comprise VCO 2 R and CcCO 2 R values. This is accomplished by enriching the inspired breathing gases with CO 2 . The breathing gases are then, again, returned to the normal condition.
The normal (N) breathing values (N) and reduced (R) gas transfer values (R) are used as data points for a regression analysis, such as a linear regression analysis. Graphically, the data points may be plotted on a graph in which the end capillary CO 2 blood quantity values, such as CcCO 2 , are scaled along the abscissa and values for the released amount of CO 2 (VCO 2 ) are scaled along the ordinate. Such a graph is shown in FIG. 1 . For simplicity only, a single set of N and R data points are shown in FIG. 1 as points 10 and 12 , respectively. The regression analysis produces a straight line 14 providing the best fit for the data points. In the simplified example shown in FIG. 1 , this is a straight line intersecting the two data points. The downward slope of line 14 makes it clear that the greater the amount of CO 2 that is released in the exhalations of the subject, the less will be the end capillary blood CO 2 content of the subject.
It will also be appreciated that the slope of line 14 represents the functional cardiac output of the subject as expressed in the differential form of the Fick equation, Equation 2. That is, the difference between the amount of CO 2 (VCO 2 ) released under normal (N) conditions and that released under reduced (R) gas transfer conditions shown along the ordinate of FIG. 1 represents the numerator of Equation 2. The corresponding situation exists with respect to the difference in end capillary blood CO 2 content (CcCO 2 ) shown on the abscissa of FIG. 2 and forming the denominator of Equation 2. When Equation 2 is presented graphically in the manner shown in FIG. 1 , the functional cardiac output thus determined will have a negative sign due to the transposition of the quantities forming the denominator of the equation.
FIG. 2 shows a device suitable for incorporating the apparatus of the present invention and carrying out the method of the present invention. The breathing organs of the subject, including lungs 20 are supplied with breathing gases through breathing circuit 22 of conventional construction. Breathing circuit 22 includes inspiration limb 24 that supplies breathing gases to the subject and expiration limb 26 that receives exhaled gases from the subject. Inspiration limb 24 and expiration limb 26 are connected to two arms of Y-connector 28 . A third arm of Y-connector 28 is connected to patient limb 30 . Patient limb 30 supplies and receives breathing gases to/from the subject through an endotracheal tube, face mask, or other appliance (not shown).
The other ends of inspiration limb 24 and expiration limb 26 are connected to ventilator 32 . Ventilator 32 provides breathing gases in inspiration limb 24 and receives breathing gases from expiration limb 26 .
The patient limb accommodates also a flow sensor 34 connected through a signal line 36 to the monitor 38 . A flow measuring apparatus suitable for use in breathing circuit 22 is shown in U.S. Pat. No. 5,088,332 to Instrumentarium Corp. of Helsinki, Finland. A hot wire anemometer may also be used for this purpose. The flow sensor may also be placed elsewhere in the circuit than at the location shown in FIG. 2. A CO 2 sensor 40 is also located at the patient limb. This sensor can be of mainstream type when the signal line 42 is an electrical one and the active sensor element, typically based on infrared light absorption, is measuring the gas flow in the patient limb. Alternatively, the CO 2 sensor 40 may be of sidestream type, when the element in the patient limb is a sampling port and the line 42 is a sampling line conveying a sample gas flow to the infrared analysis within the monitor 38 . The CO 2 sensor is used to determine the end-tidal CO 2 concentration and, together with the flow signal from flow sensor 34 , is used to determine the CO 2 elimination from the lungs by integrating the product of instantaneous flow and the corresponding CO 2 concentration.
The output of sensors 34 and 40 are provided in signal lines 36 and 42 to monitor 38 in which the integration of flow rates to obtain volumes, filtering, or other signal processing is carried out to produce values for the sensed quantities.
Sensors 34 and 40 and monitor 38 measure gas flows, expired CO 2 concentrations, and end tidal CO 2 gas concentrations. Measured expired CO 2 concentrations and gas flows can be used to determine the amount of CO 2 (VCO 2 ) released from the blood. The end tidal CO 2 concentration is used to determine quantities indicative of the CO 2 content of the blood, such as CcCO 2 , as described above.
As shown in FIG. 2 , the CO 2 exchanger apparatus 50 of the present invention is located in the patient limb 30 . One embodiment of the exchanger apparatus is shown in FIGS. 3 a and 3 b. CO 2 exchanger apparatus 50 has housing 52 with ports 54 and 56 for connecting the CO 2 exchanger apparatus in patient limb 30 , as shown in FIG. 2 . As shown in FIG. 2 , CO 2 exchanger apparatus 50 is connected in patient limb 30 upstream of CO 2 sensor 40 . That is, CO 2 sensor 40 is positioned between CO 2 exchanger apparatus 50 and the subject, i.e. subject's lungs 20 . Housing 52 of CO 2 exchanger apparatus 50 includes a moveable element 58 containing a substance capable of taking up a quantity of CO 2 from expiration breathing gases passing through the element and thereafter releasing the taken up quantity of CO 2 to inspired breathing gases subsequently passing through the element. For this purpose and by way of example, element 58 may comprise a porous housing 60 containing activated charcoal rods. Such a material adsorbs the CO 2 from the high CO 2 partial pressure expiration breathing gases, and due to the weakness of the bonding of the CO 2 to the absorption material, thereafter releases or relinquishes the CO 2 to the low CO 2 partial pressure inspiration breathing gases. The two-way taking up and releasing action of the CO 2 exchanger of the present invention distinguishes it from a CO 2 absorber conventionally found in recirculating breathing circuits. The function of a CO 2 absorber is to permanently remove CO 2 from the breathing gases of a patient. The activated charcoal rods may, for example, be 1 mm in diameter and 1-5 mm in length. A typical volume of material for taking up CO 2 and releasing a sufficient quantity to adequately increase the alveolar CO 2 partial pressure is 10-30 ml, depending the exact geometry of apparatus 50 and element 58 . For an apparatus suitable for pediatric patients the volume of CO 2 absorption/release material may be smaller. Other materials, such as zeolite with pore sizes suitable for the adsorption of CO 2 may also be used.
Element 58 may be moved from a position which is shown as an upper position in FIG. 3 a, to a lower position shown in FIG. 3 b. In the simplest embodiment of the invention, a manual actuator 64 may be employed as a transfer mechanism for this purpose. In a typical, practical embodiment of the present invention shown in FIG. 2 , manual actuator 64 is replaced with an electrical solenoid or linear motor 66 operable by a signal in line 68 from monitor 38 . It would also be possible to provide a pneumatic actuator in apparatus 50 .
With element 58 in the raised, upper position shown in FIG. 3 a, breathing gases to/from the patient proceed directly between ports 54 and 56 of housing 52 of apparatus 50 . With element 58 in the lowered position, shown in FIG. 3 b, breathing gases passing between ports 54 and 56 pass through element 58 and the gas take up/release substance 62 . A seal 67 may be provided in the lower portions of housing 52 to accommodate element 58 when it is in the lowered position.
The method for carrying out the method of the present invention is as follows. The method is described as in an instance using air for the breathing gases. Respiration may be either spontaneous on the part of the subject or assisted by the ventilation apparatus shown in FIG. 2 .
Element 58 of apparatus 50 is placed in the upper position shown in FIG. 3 a. The subject breathes, or is ventilated, with breathing gases such as air. The normal (N) breathing action of the subject is allowed to stabilize. This may, for example, require a minimum of five breaths or a half a minute to a minute of time. The amount of CO 2 released from the blood in the lungs of the subject and the CO 2 concentration in the breathing gases are then measured, for at least one breath, or preferably for each of a plurality of breaths, of the subject using sensors 34 and 40 . Typically, the CO 2 concentration is measured as the end tidal CO 2 concentration (P ET CO 2 N ). One or more values of VCO 2 (N) are determined. In this exemplary description, the quantity used to describe the end capillary blood CO 2 condition is the CO 2 content (CcCO 2 ). The measured end tidal CO 2 concentrations are thus used to determine CcCO 2 and one or more CcCO 2 N values are obtained from the end tidal CO 2 levels for the breaths.
Thereafter, the CO 2 content of the breathing gases inhaled by the subject is increased to increase the CO 2 concentration in the lungs of the subject and to reduce CO 2 gas transfer, i.e. (R) breathing conditions. Using the apparatus shown in FIG. 3 a, this may be accomplished by lowering element 58 to place the element in the breathing gas flow path between ports 54 and 56 , as shown in FIG. 3 b.
The end tidal CO 2 levels are examined as the subject breathe under these conditions. FIG. 4 shows a read out of the CO 2 levels of the breathing gas passing CO 2 sensor 40 downstream of apparatus 50 . Prior to time 70 , element 58 in apparatus 50 is in the raised position so that the breathing action of the subject is in the normal (N) one described above. For each breath, the CO 2 level starts at essentially zero during inhalation and rises to about 5% in the exhaled breathing gases.
At time 70 , element 58 is lowered into the breathing gas passage between parts 54 and 56 . Element 58 commences its CO 2 taking up and releasing action. This causes the CO 2 content of the inhaled breathing gases to rise to over 1% and the CO 2 content of the exhaled breathing gases to increase to about, or over, 6%, as shown in FIG. 4 . The result is an increase in the inspired CO 2 content of about 1.0% which is considered optimal in carrying out the determination of functional cardiac output.
When the end tidal CO 2 levels no longer change, this indicates that the alveolar CO 2 concentration in the lungs is constant, which means that CO 2 storage in the lungs has been accommodated. The measurement of the amount of gas released from the lungs of the subject and CO 2 concentrations of the breathing gases, i.e. end tidal CO 2 concentration, is then commenced. After measurements are taken, the enrichment of CO 2 in the inhaled breathing gases may thereafter be terminated by raising the CO 2 take up/release element 58 to the upper position shown in FIG. 3 a at time 72 .
The exact amount and duration of the CO 2 enrichment will depend on numerous physical and physiological factors of the patient and on the data needed to accurately determine functional cardiac output. For a typical adult, CO 2 enrichment would last about 6 or 10 breaths.
The amount of end-tidal CO 2 increase is governed by somewhat conflicting considerations. The larger the increment, the larger will be the alveolar CO 2 concentration in the lungs and the end capillary blood CO 2 content (CcCO 2 ). This will place the R data point 12 farther from the abscissa of FIG. 1 and improve the accuracy of the FCO determination. On the other hand, the larger the CO 2 increase is, the less CO 2 gas exchange occurs in the lungs of the subject resulting in higher CO 2 blood levels that require a longer time to return to normal levels. The optimum of CO 2 increase a combination of these factors and need be no greater than that required to achieve the desired results.
The amount of CO 2 released from the blood of the subject (VCO 2 R ) is determined by subtracting the amount of CO 2 in the enriched, inhaled breathing gases from the CO 2 amount measured in the exhaled breathing gases. The measured end tidal CO 2 levels are used to determine the end capillary blood CO 2 content CcCO 2 R . These determinations are carried out from measurements obtained within the circulation period of the blood in the body of the subject following the switching of actuator 64 , 66 to transfer the CO 2 take up/release element 58 into the breathing gas flow path. This is a period of approximately 20 seconds to one minute. In this period, the venous blood CO 2 content (CvCO 2 ) remains constant since it has not yet returned to the lungs to undergo gas exchange.
If desired, an administration of increased CO 2 in the inhaled breathing gases to the subject can be repeated after an appropriate interval during which CO 2 levels in the blood return to normal.
A regression analysis, such as a linear regression analysis, is then performed using the normal (N) values obtained from the initial breaths of the patient prior to time 70 in FIG. 40 and the reduced (R) gas transfer values obtained following the increase in the CO 2 content of the inhaled breathing gases, i.e. after time 70 . It will be appreciated that the data used to perform the regression analysis can include many normal (N) values obtained from the plurality of normal breaths taken by the patient. There will be a smaller number of R values due to the time limitation set by the blood recirculation.
As noted above, the slope of line 14 produced by the regression analysis is the negate of the functional cardiac output (FCO) of the patient.
FIG. 5 presents an alternate embodiment in which the CO 2 take the CO 2 up/release element is positioned in parallel with a heat and moisture exchanger (HME). Specifically, apparatus 501 contains CO 2 take up/release element 581 . Element 581 may be similar in construction to element 58 except that it is not moveable in the housing 502 of apparatus 501 . Housing 502 contains ports 504 and 506 . Part 504 may be connected in patient limb 30 . Part 506 is connected to valve 80 .
Heat and moisture exchanger 82 is connected in parallel with apparatus 501 between patient limb 30 and valve 80 . Valve 80 is also connected to patient limb 30 . Heat and moisture exchanger 82 may be of conventional construction and includes a component 84 , schematically shown in FIG. 5 , for carrying out its intended purpose.
By the appropriate operation of valve 80 , the breathing gases of the subject can bypass apparatus 501 and pass through heat and moisture exchanger 82 , as prior to time 70 and subsequent to time 72 , or pass through apparatus 501 , as between timer 70 and 72 .
It is preferable that the volumes of the apparatus 501 and its associated flow paths and the volume of heat and moisture exchanger 82 and its associated flow paths be made essentially equal to avoid changes in the gas exchange of gases other than CO 2 . An adult heat and moisture exchanger is typically 40 ml by volume, and for pediatric patients the volume may be 15 ml.
It is recognized that other equivalents, alternatives, and modifications aside from those expressly stated, are possible and within the scope of the appended claims.
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Apparatus and method for providing breathing gases to a subject employs an exchanger taking up a quantity of a given component, such as CO 2 , from expiratory breathing gases passing through the exchanger and thereafter releasing the given component in inspiratory breathing gases subsequently passing through the exchanger. The exchanger may be selectively inserted in a flow path for the breathing gases for this purpose. Or, the breathing gases may be selectively passed through and bypassed around the exchanger. The apparatus and method may be used for non-invasive determination of the functional cardiac output of a patient using the differential form of the Fick equation.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 USC 119 of foreign application DE 10 2011 119 986.5 filed in Germany on Dec. 2, 2011, and which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates to a liquid filter, in particular for oil, fuel or water, in particular of an internal combustion engine, in particular of a motor vehicle, with a filter housing that features at least a first passage for the inlet of liquid and at least a second passage for the outlet of the liquid and in which a filter element is disposed, that separates the at least first passage from the at least second passage and that features a filter medium which surrounds closely the circumference of an element interior space of the filter element relative to an imagined filter element axis which is connected with the at least one passage, and which is surrounded by an element exterior space that is connected with the other at least one passage, and that can be flowed through for filtering liquid relative to the filter element axis radially outside, from the element exterior space towards radially inside to the element interior space, or reversely, and with an additive container for the liquid which is disposed in the element interior space and which features at least one flow through opening for liquid which connects a container interior space of the additive container with at least one area of the element interior space outside of the additive container.
[0003] Furthermore, the invention relates to a filter element of a liquid filter, in particular for oil, fuel or water, in particular of an internal combustion engine, in particular of a motor vehicle that can be disposed in a filter housing that features at least a first passage for the inlet of the liquid and at least a second passage for the outlet of the liquid, in such a way that it separates the at least first passage from the at least second passage and that features a filter medium which surrounds closely the circumference of an element interior space of the filter element relative to an imagined filter element axis which can be connected with the at least one passage, and that can be flowed through for filtering liquid relative to the filter element axis radially outside towards radially inside to the element interior space, or reversely, and that features an additive container for an additive for the liquid which is disposed in the element interior space and which features at least one flow through opening for liquid which connects a container interior space of the additive container with at least one area of the element interior space outside of the additive container.
BACKGROUND OF THE INVENTION
[0004] An oil treatment filter for being used in an internal combustion engine is known from U.S. Pat. No. 7,018,531 B2. The oil treatment filter features a mechanical filter element and a central additive container for a gradual discharge of an oil additive. The additive container contains an oil treatment material. The additive can be provided as massive block in a storage chamber of the additive container. The additive can also be provided in the form of tablets. The central arrangement of the additive container allows a filtration of the liquid through the mechanical filter element before the additive is added. This reduces the probability of additive being filtered too early after its initial addition. The additive container has an opening which allows a fluid connection between a storage chamber in the additive container and the exterior side of the additive container.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to realize a liquid filter and a filter element of a liquid filter of the above-mentioned type in which the additive container mechanically supports and stabilizes the filter element, in particular the filter medium, additionally.
[0006] The object is solved according to the invention by the fact that at a radially outer circumferential side of the additive container relative to the filter element axis is disposed at least one spacer which, on the one hand, is supported by the radially outer circumferential side of the additive container and, on the other hand, is supported directly or indirectly with its side facing away from the radially outer circumferential side of the additive container at the radially internal circumferential side of the filter medium facing the element interior space relative to the filter element axis.
[0007] According to the invention, the filter medium is thus supported by the at least one spacer against the circumferential side of the additive container. In this way, the additive container stabilizes the filter medium additionally. Furthermore, the additive container is positioned through the at least one spacer in the element interior space. The manufacture and assembly of the filter element can be simplified by the at least one spacer. The radially outer circumferential side of the additive container is kept at a distance to the radially inner circumferential side of the filter medium by the at least one spacer. In this way, a flow chamber for the liquid is realized between the additive container and the filter medium. This flow chamber is connected fluidically via the flow through opening with the container interior space of the additive container and with the radially inner circumferential side which, depending on the flow direction of the liquid through the filter medium, designates either the raw side or the clean side of the filter medium. The at least one spacer can be supported directly at the radially inner circumferential side of the filter medium so that the additive container itself can ensure the function of a support tube and that a separate support tube is not required. When using a support tube for supporting the filter medium, the at least one spacer can also be supported indirectly via the support tube on the inner circumferential side of the filter medium. The filter medium can advantageously be closed circumferentially in a zigzag-folded manner. Thanks to the zigzag folds, a relatively large and active filtration surface can be obtained in comparison with the outside dimensions of the filter element, The at least first passage can be at least an inlet for the liquid to be filtered and to be treated with the additive. The at least second passage can be at least an outlet for the filtered and with additive treated liquid. The imaginary filter element axis can coincide with a corresponding symmetry axis, a central axis and/or a gravity axis of the filter element, the filter housing and/or the filter medium. It can additionally or alternatively coincide with an axis of the filter housing, in particular a screw-in axis of a screwed connection between the filter housing and the filter head. Advantageously, the filter medium can clamp with its inner circumferential side a cylinder jacket or an envelope of cone, the height axis of which can define the imaginary filter element axis. As an additive container in the meaning of the invention a kind of tank is preferably understood, the wall areas of which and the bottom area are closed to a great extent. Openings in the wall areas and the bottom area are so small that the additive contained in the additive container cannot pass through them to the exterior. The additive container is therefore also suited, in particular in contrast to a grid-like or frame-like additive carrier, to accept gel-like or granular additives.
[0008] In an advantageous embodiment, the at least one spacer can feature at least one sup-porting rib that can extend with respect to the filter element axis at least circumferentially along at least one part of the radially outer circumferential side of the additive container. The at least one supporting rib can simply be disposed on the exterior side of the additive container, in particular it can be integrally molded, glued or welded. It can be connected as one piece with the peripheral wall of the additive container. The circumferential extension of the supporting rib makes it possible that the supporting forces, which have an effect between the peripheral wall of the additive container and the inner circumferential side of the filter medium, can have an even impact along the peripheral wall of the additive container. Furthermore, the positioning of the additive container can thus be simplified in the element interior space. Furthermore, the support function acting on the filter medium can be enhanced In this way. Advantageously, the at least one supporting rib can extend in addition also to the circumferential extension in axial direction with respect to the filter element axis. In this way, the active surface of the peripheral wall of the additive container serving as support can be enlarged. Advantageously, the at least one supporting rib can also extend substantially in circumferential direction.
[0009] Advantageously, the at least one supporting rib can extend along an imaginary helical line on the radially outer circumferential side of the additive container. In this way, the surface of the peripheral wall of the additive container, which serves as support, can be enlarged easily. An even support can be realized between the additive container and the filter medium. A supporting rib extending along the helical line can be realized easily. The screw-shaped arrangement of the at least one supporting rib can further-more enhance a flow of the liquid in the flow chamber between the circumferential side of the additive container and the inner circumferential side of the filter medium. Thus, the filter function and the treatment with the additive can be enhanced. Advantageously, several screw-shaped supporting ribs can run parallel to each other. Two adjacent supporting ribs each can define a screw-shaped flow chamber.
[0010] In another advantageous embodiment, the at least one spacer can feature at least one supporting rib that can extend in parallel or diagonally with respect to the filter element axis. Straight supporting ribs can be realized easily. Supporting ribs running parallel to the filter element axis can simplify the installation of the additive container in the element interior space.
[0011] Advantageously, the at least one supporting rib can feature at least one discontinuity. A gap between two supporting ribs in alignment to each other can also be considered as discontinuity. Conversely, two supporting ribs in alignment to each other in their extension direction can be considered as one supporting rib with one discontinuity. The liquid can flow through the at least one discontinuity so that a distribution and a flow of the liquid in the flow chamber between the additive container and the filter medium can be enhanced. Thus, an even liquid distribution along the circumferential side of the additive container can be realized. Thus, an even contact with the additive and an even treatment of the liquid with additive can be made possible via the at least one flow through opening.
[0012] In another advantageous embodiment, the radially outer circumferential side of the additive container can be cylindrical or conical, and coaxial with respect to the filter element axis. Advantageously, the radially inner circumferential side of the filter medium can be accordingly cylindrical or conical. A cylindrical or conical additive container can be adapted optimally to a cylindrical or conical shape of the element interior space. In this way, a radial extension of the flow chamber between the additive container and the inner circumferential side of the filter medium can be uniform in axial direction and in circumferential direction. Thus, the fluid flow can be enhanced in this flow chamber. This can have a positive impact on the pressure ratio between a clean side and a raw side of the filter medium. The filtration effect can thus be enhanced. Furthermore, the service life of the filter element and of the liquid filter, respectively, can be extended.
[0013] Advantageously, the filter medium can be zigzag-folded circumferentially and the at least one spacer can extend circumferentially over at least two, preferably three, fold edges that form the radially inner circumferential side of the filter medium. The circumferential extension of the spacer over at least two, preferably three, fold edges can pre-vent the at least one spacer in embodiments of the filter element, in which the at least one spacer is adjacent directly to the inner circumferential side of the filter medium, which means the fold edges there, from being inserted between two adjacent fold edges. Thus, it can be avoided that a spacer inserted between two adjacent fold edges pushes apart the adjacent fold edges, which could impair the filtration effect of the filter medium. A uniform support on the radially inner fold edges of the filter medium can be realized.
[0014] In another advantageous embodiment, the at least one spacer can be supported at a radially inner circumferential side of a support tube of the filter element which can be disposed in the element interior space and on the radially outer circumferential side of which the radially inner circumferential side of the filter element can be supported indirectly or directly. The support tube can support the filter medium to stabilize its shape. The filter element with the filter medium and the support tube can also be prefabricated and the additive container can be installed easily in the element interior space during a later assembly step. The additive container can be supported by the at least one spacer in a stable manner on the inner circumferential side of the support tube, which means indirectly on the inner circumferential side of the filter medium. Thus, the additive container can be positioned easily in the interior area of the support tube. Advantageously, the additive container can be disposed coaxially in relation to the support tube. Thus, the additive container can be easily inserted into the element interior space without the need of additional positioning elements.
[0015] In another advantageous embodiment, the additive container can be connected, in particular glued or welded, at least on one front face with an end body, in particular an end plate, of the filter element which in turn is connected, in particular glued or welded, with a front face of the filter medium. In this way, the stability of the connection between the additive container and the filter medium can be further enhanced. This can have a positive effect on the stability of the entire filter element. A glued connection or a welded connection can be realized easily. A glued connection or a welded connection can furthermore also realize a sealing function. The end body, in particular the end plate, can stabilize the filter medium additionally on its front face. Furthermore, the end body can tightly seal the filter medium at its front face so that no liquid can enter or leave the element interior space.
[0016] The technical object is further solved by the filter element according to the invention by the fact that at a radially outer circumferential side of the additive container relative to the filter element axis is disposed at least one spacer which, on the one hand, is sup-ported by the radially outer circumferential side of the additive container and, on the other hand, directly or indirectly with its side facing away from the radially outer circumferential side of the additive container at the radially internal circumferential side of the filter medium facing the element interior space relative to the filter element axis. The advantages and features shown above in conjunction with the liquid filter according to the invention are valid for the filter element according to the invention and its advantageous embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying Figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
[0018] Features of the present invention, which are believed to be novel, are set forth in the drawings and more particularly in the appended claims. The invention, together with the further objects and advantages thereof, may be best understood with reference to the following description, taken in conjunction with the accompanying drawings. The drawings show a form of the invention that is presently preferred; however, the invention is not limited to the precise arrangement shown in the drawings.
[0019] FIG. 1 schematically depicts a half section of a spin-on filter for engine oil of an internal combustion engine of a motor vehicle with a filter element in the element interior space of which is disposed an additive container according to a first example of an embodiment which is supported with screw-shaped supporting ribs on an inner circumferential side of a support tube of the filter element;
[0020] FIG. 2 schematically depicts an isometric representation of the additive container of the spin-on filter from FIG. 1 ; and
[0021] FIG. 3 schematically depicts an isometric representation of an additive container according to a second example of an embodiment which is similar to the additive container in FIGS. 1 and 2 and which can be used with the spin-on filter in FIG. 1 .
[0022] Identical components in the figures have the same reference numerals. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION
[0023] Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of apparatus components related to a liquid filter and a filter element with an additive container. Accordingly, the apparatus components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
[0024] In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0025] FIG. 1 shows a spin-on filter 10 for engine oil in a lengthwise half section. The spin-on filter 10 is screwed to a filter head of a filtering device, not shown in figure 1 , of an engine oil line of an internal combustion engine of a motor vehicle which is of no interest here.
[0026] The spin-on filter 10 has a filter housing 12 with a pot 14 and a cover 16 . In at least some embodiments, such as the illustrated exemplary embodiment of FIG. 1 , the pot 14 is permanently and securely fixed to the cover 16 via a liquid-tight flare coupling such that the filter element 26 and filter housing 12 are one-piece unitary and replaced as a unit. A sealing 18 is disposed in a bead in the area of the flare coupling.
[0027] Several inlet ports 20 through which the engine oil to be cleaned can flow into the spin-on filter 10 are disposed in the cover 16 . Furthermore, the cover 16 has a centrally disposed cover outlet 22 which features an internal thread for attaching the spin-on filter 10 on an outer thread of a cylindrical connecting branch of the filter head. The cover outlet 22 and the connecting branch are coaxial in relation to an imaginary axis 24 of the spin-on filter 10 . In the shown example of an embodiment, the axis 24 coincides with a screw-in axis of the spin-on filter 10 around which the filter housing 12 is screwed on the connecting branch of the filter head. If, in the following, it is referred to “axial”, “radial” or “circumferentially”, this refers to the axis 24 , unless otherwise mentioned.
[0028] A filter element 26 is disposed in the inside of the housing 12 . The filter element 26 separates the inlet ports 20 tightly from the cover outlet 22 . For this purpose, the filter element 26 has a filter medium 28 which is closed circumferentially in a zigzag-folded and star-shaped manner. The filter medium 28 defines a radially inner element interior space 30 of the filter element 26 on a clean side of the filter element 26 . The radially inner circumferential side of the filter medium 28 , and therefore the element interior space 30 , are substantially cylindrical. In the example of an embodiment shown in FIG. 1 a filter medium axis of the filter medium 28 and an axis of the filter element 26 coincide with the axis 24 .
[0029] A bottom end plate 32 and a connection end plate 34 are attached at the front faces of the filter medium 28 . The bottom end plate 32 and the connection end plate 34 are preferably made of synthetic material. The bottom end plate 32 closes the element interior space 30 on the front face of the filter element 26 facing the bottom of the pot 14 , in FIG. 1 below. Support members 36 support the bottom end plate 32 against the bottom of the pot 14 .
[0030] The connection end plate 34 is substantially designed as annular plate, the inner section of which in the shape of a connecting piece is bent away from the element interior space 30 . A central opening of the connection end plate 34 forms a coaxial element outlet 38 in relation to the cover outlet 22 , through which leads the connecting branch of the filter head when the spin-on filter 10 is mounted. The element outlet 38 is tightly connected with the connecting branch. In this way, the clean-sided element interior space 30 of the filter element 26 is separated from a raw side 40 of the filter medium 28 . An annular space 42 that surrounds the filter medium 28 radially outside is disposed at the raw side 40 .
[0031] A support tube 44 that is coaxial in relation to the axis 24 extends between the bottom end plate 32 and the connection end plate 34 in the element interior space 30 . The support tube 44 is preferably made of synthetic material. The support tube 44 is firmly connected, preferably glued or welded, with the bottom end plate 32 and with the connection end plate 34 as well. The radially inner circumferential side of the filter medium 28 is placed directly on the radially outer circumferential side of the support tube 44 . The support tube 44 has in its peripheral wall a plurality of inlet apertures 46 for the filtered engine oil. The internal diameter of the support tube 44 is larger than the outer diameter of the element outlet 38 .
[0032] An additive container 48 shown in detail in FIG. 2 is furthermore disposed in the element interior space 30 . The additive container 48 contains an additive for treating the engine oil. The additive is not shown in FIG. 1 to ensure a better clarity. The additive can preferably be available as gel. However, it can also be available as granulate or in tablet form. When the spin-on filter 10 is in operation, the additive is gradually delivered to the engine oil that flows through the spin-on filter 10 .
[0033] The additive container 48 features a lower cylinder-shaped storage section 50 which is disposed coaxially in relation to the axis 24 . With a lower front face shown in FIG. 1 , the storage section 50 that is open there is supported tightly on the bottom end plate 32 . The storage section 50 forms in conjunction with the bottom end plate 32 a tank that is substantially closed towards the bottom and circumferentially. This tank is also able to receive a fluid or granular additive. At the side facing the connection end plate 34 , the storage section 50 merges into a one-piece cross bracing 52 . At the side facing the connection end plate 34 , the cross bracing 52 is supported at the interior side of the connection end plate 34 facing the element interior space 30 in axial direction. Thus, the additive container 48 is completely fixed between the connection end plate 34 and the bottom end plate 32 in axial direction. The cross bracing 52 consists of four crosswise arranged plates 54 that extend each radially and axially in relation to the axis 24 . The plates 54 meet in the axis 24 and are connected there with each other to form one piece.
[0034] The storage section 50 features at its front face facing the cross bracing 52 an opening that is divided by the plates 54 into four similar opening segments 56 . The opening segments 56 are among others shown in FIG. 2 . In the circumferential side of the storage section 50 , a plurality of inlet apertures 58 for engine oil is disposed in circumferential direction and in axial direction. The diameters of the inlet apertures 58 are small compared with the total area of the circumferential side of the storage section 50 . They are dimensioned in such a way that the additive cannot flow through them from the additive container 48 into the element interior space 30 surrounding the container. The diameters of the inlet apertures 58 and/or their total area can be predefined for setting a discharge quantity of additive per flow rate of engine oil.
[0035] A plurality of supporting ribs 60 is disposed at the radially outer circumferential side of the storage section 50 . The supporting ribs 60 are connected each as one piece with a peripheral wall of the storage section 50 . The supporting ribs 60 are bent diagonally downwards towards the bottom end plate 32 . The supporting ribs 60 extend each in a screw-shaped manner around the axis 24 . The supporting ribs 60 run parallel to each other. They extend in axial direction over the complete storage section 50 . The supporting ribs 60 extend each in radial direction up to the radially inner circumferential side of the support tube 44 . The supporting ribs 60 are supported indirectly by the side facing away from the outer circumferential side of the storage section 50 of the additive container 48 via the support tube 44 at the radially inner circumferential side of the filter medium 28 . In this way, the additive container 48 supports the filter medium 28 via the supporting ribs 60 and the support tube 44 and stabilizes the filter element 26 . Furthermore, the supporting ribs 60 position the additive container 48 in the element interior space 30 .
[0036] Each supporting rib 60 features a plurality of discontinuities 62 . The discontinuities 62 are disposed each in the area of one of the inlet apertures 58 . Due to the discontinuities 62 , screw-shaped flow chambers 64 , which extend each between two adjacent supporting ribs 60 , are connected with each other.
[0037] The areas of each of the supporting ribs 60 between two discontinuities 62 extend each circumferentially over at least two, preferably at least three, radially inner fold edges of the zigzag-folded filter medium 28 . In this way, the additive container 48 is uniformly supported in relation to the support tube 44 and the filter medium 28 .
[0038] When the spin-on filter 10 is operating, engine oil is delivered from the engine-oil circuit through the inlet ports 20 to the annular space 42 . The engine oil flows through the filter medium 28 from the annular space 42 , radially outside, to the element interior space 30 , radially inside, shown in FIG. 1 by an arrow 66 . The filtered engine oil flows through the support tube 44 through the inlet aperture 46 and reaches the flow chambers 64 between the storage section 50 of the additive container 48 and the support tube 44 . From there, one part of the filtered engine oil reaches through the inlet apertures 58 a container interior space 68 of the additive container 58 . In the container interior space 68 , the engine oil comes into contact with the additive therein which is gradually delivered to the engine oil. The engine oil that is filtered and treated with additive passes the cross bracing 52 that homogenizes the flow. The engine oil flows through the element outlet 38 and the cover outlet 24 , shown in FIG. 1 by an arrow 70 , from the spin-on filter 10 into the connecting branch of the filter head and from there back to the engine-oil circuit.
[0039] In FIG. 3 is shown a second example of an embodiment of an additive container 148 which is similar to the additive container 48 from the first example of an embodiment in FIGS. 1 and 2 . Those elements that are similar to those in the first example of an embodiment have the same reference numerals. The second example of an embodiment is different from the first example of an embodiment by the fact that instead of the screw-shaped supporting ribs 60 a plurality of supporting ribs 160 is provided that extend each in axial direction. The supporting ribs 160 are disposed in four each axially extending groups with five supporting ribs 160 each. The supporting ribs 160 of an axial group are aligned in axial direction. Between the adjacent supporting ribs 160 of an axial group there is one discontinuity 62 each. In other words, each axial group of supporting ribs 160 represents one axial supporting rib that is divided by the four discontinuities 64 into four supporting rib parts 160 . The four supporting rib groups are evenly distributed at the radially outer circumferential side of the storage section 50 .
[0040] Furthermore, the cross bracing 152 in the second example of an embodiment has four supporting lugs 172 which are disposed each radially outside at the free sides of the plates 54 facing away from the storage section 50 and extend in axial direction away from the storage section 50 . When the spin-on filter 10 is assembled, the supporting lugs 172 are supported at the connection end plate 34 of the filter element 26 . The sup-porting lugs 172 act as further spacers via which a flow chamber 174 is realized which connects the four volume sections between the plates 54 .
[0041] In all above described examples of an embodiment of a spin-on filter 10 and a filter element 26 , the following modifications are among others possible:
[0042] The invention is not limited to spin-on filters 10 for engine oil of internal combustion engines. Rather, it can also be used with different liquid filters, for example for fuel or water. The invention can also be used outside the automotive technology, for example with industrial engines.
[0043] Instead of the spin-on filter 10 , it is also possible to use a filter with an openable filter housing in which the filter element 26 can be disposed replaceably.
[0044] Instead of being disposed in the area of the inlet apertures 58 , the discontinuities 62 of the supporting ribs 60 can also be disposed in distant areas of the peripheral wall of the storage section 50 .
[0045] At least in the first example of an embodiment in FIGS. 1 and 2 the support tube 44 is not required. In this case, the supporting ribs 60 can be supported directly at the inner circumferential side of the filter medium 28 , which means the radially inner fold edges there.
[0046] In the first example of an embodiment, only one screw-shaped extending supporting rib can be provided instead of the plurality of screw-shaped extending supporting ribs 60 .
[0047] In the second example of an embodiment, the supporting ribs 160 can also extend diagonally in relation to the axis 24 instead of extending in axial direction.
[0048] Instead of the screw-shaped supporting ribs 60 and the axial supporting ribs 160 , circumferentially extending supporting ribs can also be provided.
[0049] The cross bracing 52 is also not needed. Another axial supporting device can also be provided instead. The storage section 50 can also extend in axial direction up to the connection end plate 34 where it can be supported. Advantageously, larger inlet apertures and/or a larger number of inlet apertures 58 can then be provided in the storage section 50 in the area of the connection end plate 34 . The storage section 50 can also only partially be filled with additive.
[0050] The storage section 50 can also be firmly connected, for example by gluing or welding, with the bottom end plate 32 .
[0051] The storage section 50 can also be open completely or only sectionwise towards the bottom end plate 32 .
[0052] The corresponding axes of the filter element 26 and/or the filter medium 28 and/or the additive container 48 ; 148 and/or the screw-in axis and/or the axis 24 of the spin-on filter 10 must not all coincide.
[0053] It is also possible to provide only one inlet port 20 .
[0054] Instead of only one cover outlet 22 , several outlet ports for the engine oil can also be provided.
[0055] The filter element 26 can also be designed in such a way that the filter medium 28 can be flowed through in reverse direction, which means from radially inside to outside, rather from radially outside to inside. In this case, the positions of the inlet ports 20 and of the cover outlet 22 can be changed accordingly.
[0056] Instead of the screwed connection, the spin-on filter 10 can also be detachably connected by means of another connection, for example by means of a bayonet connection, with the filter head.
[0057] Instead of synthetic material, the bottom end plate 32 and/or the connection end plate 34 and/or the support tube 44 can also be made of a different material, for example metal.
[0058] Instead of the zigzag-folded filter medium 28 , another filter medium, for example a wound filter medium, that surrounds the element interior space 30 in a closed manner, can be provided.
[0059] Instead of being cylindrically shaped, the filter medium 28 can also have a different shape, for example a conical shape.
[0060] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
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A filter housing ( 12 ) includes a first passage ( 20 ) allowing liquid to enter and a second passage ( 22 ) allowing liquid to exit. A filter element ( 26 ) separates the at least first passage ( 20 ) from the at least second passage ( 22 ) and is disposed in the filter housing ( 12 ). A filter medium ( 28 ) encloses the circumference of an element interior space ( 30 ) and has at an end face an element passage ( 38 ) which is connected with the passage ( 22 ). The filter medium ( 28 ) is surrounded by an element exterior space ( 42 ) which is connected with the other passage ( 20 ). An additive container ( 48 ) is disposed in the element interior space ( 30 ) and includes at least one flow through opening ( 56, 58 ) connecting a container interior space ( 68 ) with at least one section ( 64 ) of the element interior space ( 30 ) outside of the additive container ( 48 ).
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FIELD OF THE INVENTION
The present invention relates to triazene analogs of the general formula (I) and formula (II), their tautomeric forms, stereoisomers, polymorphs, hydrates, solvates, and pharmaceutically acceptable salts thereof for the metastatic malignant melanoma and other cancers including but not limited to lymphomas, sarcomas, carcinomas, and gliomas.
The present invention further relates to a process for the preparation of the above said triazene analogs of formula (I) and formula (II), and their pharmaceutically acceptable compositions.
BACKGROUND OF THE INVENTION
Melanoma, a malignant neoplasm, is derived from cells that are capable of forming melanin, arising most commonly in the skin of any part of the body and in the eye, or rarely, in the mucus membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or lentigo maligna. In the early phases, the cutaneous form is characterized by a proliferation of cells at the dermal epidermal junction which soon invades adjacent tissues. The cells vary in amount and pigmentation of cytoplasm; the nuclei are relatively large and frequently bizarre in shape, with prominent acidophilic nucleoli; the mitotic figures tend to be numerous. Melanomas frequently metastasize widely; regional lymph nodes, skin, liver, lungs, and brain are likely to be involved.
In January 1985, the Environmental Protection Agency (EPA) predicted that depletion of the Earth's Ozone layer, which guards against ultraviolet (UV) radiation from space, would cause an increase in the number of skin cancer cases worldwide, including melanomas. The EPA estimated an annual increase of two million cases by the year 2050, when the ozone layer is expected to diminish by 10% because of human activities—primarily the release of long-lived Chlorofluorocarbons into the atmosphere (now banned in most developed countries). Public health efforts have focused on encouraging people to use sunscreen, avoid outdoor activities during peak exposure times, perform frequent self-checks of the skin, and visit dermatologists when irregularities are noted. Exposure to higher levels of ultraviolet radiation may also promote cataracts and immune system dysfunction.
UV radiation represents a definitive risk factor for skin cancer, especially when exposure occurs in combination with certain underlying genetic traits, such as red hair and fair skin ( 1 ). Pigmentation of the skin results from the synthesis of melanin in the pigment-producing cells, the melanocytes, followed by distribution and transport of pigment granules to neighboring keratinocytes. It is commonly believed that melanin is crucial for absorption of free radicals that have been generated within the cytoplasm by UV and acts as a direct shield from UV and visible light radiation ( 2 , 3 ).
UV-induced pigmentation (sun tanning) requires induction of α-melanocyte-stimulating hormone (α-MSH) secretion by keratinocytes. α-MSH and other bioactive peptides are cleavage products of Pro-Opiomelanocortin (POMC) ( 4 ). The p53 tumor suppressor gene is one of the most frequent targets for genetic alterations in cancer. p53 is a transcriptional regulator of the POMC gene, which translates to proteins that cause the melanocytes to produce melanin, which wards off skin cancer by absorbing UV radiation. Direct mutational inactivation of p53 is observed in close to half of all human tumors ( 5 ).
Malignant melanoma is a skin cancer which is, by far, one of the hardest cancers to treat today. Dacarbazine (DTIC) is the only single agent used to treat metastatic malignant melanoma. However, in the clinical setting the Complete Response (CR) rate for Dacarbazine is below 10% and hence is an unmet medical need and there exists a need for better agents. In addition. Dacarbazine is also indicated for Hodgkin's lymphoma as a secondary line therapy when used in combination with other effective drugs. Chemically. DTIC is 5-(3,3-dimethyl-1-trizeno)-imidazole-4-carboxamide with the following structural formula:
Dacarbazine, however, requires bioactivation in vivo by the liver. One of the methyl groups of the dimethyltriazeno functionality is activated by liver microsomal enzymes and, in particular, by the Cytochrome P450, to oxidation, resulting in a hydroxymethyl group. Thus, the oxidative mono-demethylation of the dimethyltriazeno functionality affords monomethyltriazene. The monomethyltriazene metabolite, 3-methyl-(triazen-1-yl)-imidazole-4-carboxamide (MTIC) is further hydrolyzed to 5-amino-imidazole-4-carboxamide (AIC), which is known to be an intermediate in purine and nucleic acid biosynthesis and to methylhydrazine, which is believed to be the active alkylating species. The Cytochrome P450 enzymes play only a minor role in the metabolism of MTIC.
Temozolomide is also a similar imidazotetrazine alkylator that methylates DNA at nucleophilic site. Temozolomide is orally bioavailable, more lipophilic, and spontaneously converted to MTIC, and also seems to generate less nausea ( 6 ). The O 6 -methylguanine adduct causes a mismatch during DNA replication and the addition of a thymidine, instead of cytosine, to the newly formed DNA strand ( 7 ). Because of the excellent CNS biodistribution, temozolomide has been useful as a radiosensitizer in both primary brain tumors and CNS metastases ( 8 - 11 ). The pharmacokinetics of temozolomide has been studied in children, and clearance is related to body surface area ( 12 ). Temozolomide improves quality of life when used with radiation in patients with brain metastases. Unlike Dacarbazine, Temozolomide has activity against sarcoma ( 13 - 15 ). Thus, it may be useful in sarcoma radiosensitization for primary control as well as for the treatment of metastases. Temozolomide is a radiosensitizer that is well tolerated and has modest side effects. The combination of Temozolomide and Irinotecan is more than additive against some cancers ( 16 ). The authors report that their experience confirms a high response rate in relapsed Ewing's sarcoma and DSRCT that is possibly even higher than that reported in the literature ( 17 - 19 ). The Temozolomide plus Irinotecan combination is less immune suppressive than standard cyclophosphamide-containing regimens ( 20 ). This might be especially important in Ewing's sarcoma since these authors and others have shown that lymphocyte recovery (i.e., absolute lymphocyte count >500 on day 15 after the first cycle of chemotherapy) is associated with significantly higher survival in Ewing's sarcoma ( 21 , 22 ). Temozolomide or Dacarbazine has also been combined with other drugs including Gemcitabine and Doxorubicin liposomes ( 23 , 24 ). The disappearance of DTIC from the plasma is biphasic with an initial half life of 19 minutes and a terminal half life of five hours. In a patient with renal and hepatic dysfunctions, the half lives were lengthened to 55 minutes and 7.2 hours, respectively. The average cumulative excretion of unchanged DTIC in the urine is 40% of the injected dose in six hours. DTIC is subject to renal tubular secretion rather than Glomerular Filtration. At therapeutic concentrations, DTIC is not appreciably bound to human plasma protein.
In humans, DTIC is extensively degraded. Besides unchanged DTIC, AIC is a major metabolite of DTIC excreted in the urine. Although the exact mechanism of action of DTIC is not known, three hypotheses have been offered:
1. Inhibition of DNA synthesis by acting as a purine analog 2. Acting as an alkylating agent 3. Interaction with SH groups Thus, the biochemical mechanism of action of the resulting MTIC reactive species whose cytotoxicity involved generation of methyl carbonium ion in vivo is thought to be primarily due to alkylation of DNA. Alkylation (methylation) occurs mainly at the O 6 and N 7 positions of guanine.
Alternatively, DTIC, prior to its metabolism to the monomethyltriazene, is oxidized initially to monohydroxymethyl and finally to an aldehyde. The monomethyltriazene, in its aldehyde form prior to oxidative monodemethylation, is cyclized to the cyclic compound (as shown in Scheme 1) which interferes with the double helix DNA structure and blocks replication of the cancer cells. And finally, the secondary metabolite, AIC, is inactive.
The imidazole ring system of the Dacarbazine is hydrophilic in nature. Therefore, there is a need in the art for possibly effective binding to the melanin such that the cytotoxic functionality of the molecule is one hundred percent effective. Thus, the present inventors have aimed to provide novel compounds with increased lipophilicity thereby providing more target specificity. Thus, Thiophene, which has a five-membered heterocyclic ring system, is lipophilic in nature and may have effective binding by increased avidity to the melanin, as a result, one would be able to get the same therapeutic effectiveness at a significantly lower dose, hence minimizing the toxicity. This would in turn afford high specificity with a larger window of the Therapeutic Index (TI). In general, for the treatment of cancer patients, a larger therapeutic index is preferred. This is because, one would like to start the therapeutic regimen with a very high Maximum Tolerated Dose (MTD) such that the cancer cells would be hit hard in the first chemotherapy itself. Otherwise, the surviving cancer cells would repair the DNA damage and subsequently metastasize to the other organs. In addition, the cancer cells that survived from the first treatment would become resistant to the second chemotherapy again, if needed. And besides, due to weakness of the immune system from the first chemotherapy, a suboptimal dose would be given in the second treatment that would contribute to toxicity.
As shown in scheme-1, unlike DTIC, better interaction of the thiophene ring system with the SH groups on the surface of the tumor antigen results in increased efficacy. This is because of sulfur (S) being larger atom and hence a five membered heterocyclic aromatic thiophene ring system resemble a phenyl ring in space, would contribute it's loan pair of electrons to the rest of the ring for better interaction with sulfhydryls at the tumor site. In addition, due to it's electronic configuration, the heterocyclic aromatic thiophene ring system may be superior over DTIC by way of inhibition of DNA synthesis by acting as a purine analog as well as acting as an alkylating agent. Also, unlike DTIC, while Amino Imidazole Carboxamide (AIC) is inactive, the corresponding Amino Thiophene Carboxamide (ATC) would very well be active in vivo via de-localization of electrons from the ring sulfur for increased efficacy. Thus, the novel triazeno thiophene analogs have several additional advantages inherently built in within the structure over dacarbazine for increased activity.
In addition to its biochemical mechanism of action, recently there are several reports in the literature for significantly increasing the efficacy of Dacarbazine by using it in combination with other chemotherapeutic agents ( 25 , 26 ). Likewise, in a pre-clinical setting, nanoemulsion preparations of Dacarbazine in a xenograft mouse melanoma model has been used to significantly increase it's efficacy ( 27 ). Similarly, a number of innovative therapeutic strategies have been pursued in order to improve the outcomes, including immune therapy, tyrosine kinase inhibitors and angiogenesis inhibitors ( 28 ). The literature reports treatment for metastatic melanoma using Dacarbazine in combination with interferons is poor ( 29 ). As described above, currently, dacarbazine and temozolamide have been extensively used chemotherapeutic agents for treating metastatic malignant melanoma. However, the success rate is low and the side effects are high. Hence, there exists an unmet medical need for the development of effective agents and approaches for treatment of metastatic malignant melanoma remains an immense challenge.
SUMMARY OF THE INVENTION
The present invention provides compounds of the formula (I), designated herein as ‘triazene analogs’.
Wherein,
R is independently selected from H, CH 3 , CH 2 OH R 1 is independently selected from OH, NHR 4 , NR 4 R 5 , SH
At least one of R 2 , and R 3 is selected from H, N═N—N(CH 3 ) 2 , N═N—NHCH 3 , N═N—N(CH 3 )CH 2 OH, CONHR 4 , CONR 4 R 5 , CONHNH 2 , CONHNHR 4 , CONHNR 4 R 5 , COOCH 3 , COOCH 2 CH 3 , COOH, COSH, CN, C≡CH, SO 2 NH 2 , SO 2 NHR 4 , SO 2 NR 4 R 5 , SO 3 H, SO 2 CH 3 , SO 2 CH 2 CH 2 NH 2 , NHCH 2 COOH, NHCH(CH 3 )COOH, NO 2 , CF 3 , Cl, Br, F, I, CCl 3 , Ph (C 6 H 5 ), CH 3 , C 2 H 5 , n-C 3 H 7 , iso-C 3 H 7 , n-C 4 H 9 , iso-C 4 H 9 , tert-C 4 H 9 , OH, OCH 3 , NH 2 , NHCH 3 , etc. electron withdrawing and electron donating groups.
R 4 and R 5 are independently selected from H, C 1 -C 10 alkyl, alkenyl, alkylol, alkylamine, etc.
X, Y, and Z are independently selected from C, N, O, and S such that the resulting five membered ring systems of the heterocyclic aromatic moieties are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
In another aspect, the present invention also provides compounds of the formula (II)
At least one of R 1 , and R 2 is independently selected from H, N═N—N(CH 3 ) 2 . N═N—NHCH 3 , N═N—N(CH 3 )CH 2 OH, CONH 2 , CONHR 4 , CONR 4 R 5 , CONHNH 2 , CONHNHR 4 , CONHNR 4 R 5 , COOCH 3 , COOCH 2 CH 3 , COOH, COSH, CN, C≡CH, SO 2 NH 2 , SO 2 NHR 4 , SO 2 NR 4 R 5 , SO 3 H, SO 2 CH 3 , SO 2 CH 2 CH 2 NH 2 , NHCH 2 COOH, NHCH(CH 3 )COOH, NO 2 , CF 3 , Cl, Br, F, I, CCl 3 , Ph (C 6 H 5 ), CH 3 , C 2 H 5 , n-C 3 H 7 , iso-C 3 H 7 , n-C 4 H 9 , iso-C 4 H 9 , tert-C 4 H 9 , OH, OCH 3 , NH 2 , NHCH 3 , etc. electron withdrawing and electron donating groups.
R 4 and R 5 are independently selected from H, C 1 -C 10 alkyl, alkenyl, alkylol, alkylamine, etc.
X, Y, and Z are independently selected from C, N, O, and S such that the heterocyclic aromatic five membered ring of the fused bicyclic systems are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole. The compound of general formula (II) is not 3-methylthiopheno[3,2-d]1,2,3-triazin-4-one (X═Y═C; Z═S; R 1 ═R 2 ═H).
In another aspect, the present invention encompasses pharmaceutically acceptable salts of the compounds of the formula (I) and (II), for example organic or inorganic acid addition salts.
In another aspect, the present invention provides compositions comprising at least one triazene analog of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and pharmaceutically acceptable carrier or diluents.
In another aspect, the present invention provides compositions comprising at least one triazene analog of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and at lest one chemotherapeutic agent and optionally pharmaceutically acceptable carrier or diluents.
In another aspect, the present invention provides compositions comprising triazene analogs of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and at lest one chemotherapeutic agent and at least one biologic response modifying agent and optionally pharmaceutically acceptable carrier or diluents.
In another aspect, the present invention provides a method of inhibiting cancer cell growth or killing a cancer cell in a patient by administering to a subject in need thereof, in an amount that is effective to kill a cancer cell, of a triazene analog of formula (I) and/or formula (II) or compositions containing the same or in combination with other chemotherapeutic agents thereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates line diagram showing percent increase in leaked Lactate dehydrogenase (LDH) from A2058 human melanoma cells, treated with various concentrations of Compound 1, Compound 6, Compound 13 and DTIC. Each point indicates percent increase in leaked LDH with respect to the vehicle control cultures, calculated from a mean of quadruplicate wells.
FIG. 2 illustrates bar diagrammatic representation of percent of cell viability of HS.531.sk normal human skin epithelial cells treated with different concentrations of DTIC and related test compounds (upper panel). Bar diagram at the lower panel represents the loss (in percentage) of HS.531.sk cell viability by various test compounds at 120 μg/ml as indicated.
FIG. 3 illustrates Western immunoblot image represents PARP cleavage in A2058 cells treated with 100 μg/ml of DTIC and test products Compound 1, Compound 6, and Compound 13. Control cultures received 0.5% DMSO as a vehicle. Expression of actin protein is shown as the loading control. Expression of the cleaved PARP protein at 89 kDa was normalized with actin expression (in arbitrary units), and represented as a bar diagram in the lower panel.
FIG. 4 represents images showing inhibition of B16F0 colony formation in presence of DTIC and Compound 6 in vitro. B16F0 cells were treated with either 0.1% DMSO (A), or 100 μg/ml of DTIC (B) or 50 μg/ml (C) or 100 μg/ml (D) of Compound 6. The average number of colonies and the average area of colonies in 0.1% DMSO (a), or 100 μg/ml of DTIC (b) or 50 μg/ml of compound 6 (c) or 100 μg/ml of compound 6 (d) treated cultures are represented in bar diagrams E and F, respectively.
FIG. 5 represents induction of cell cycle arrest in G2/M phase by Compound 6. B16 F0 Cells were treated with the indicated concentrations of either vehicle (0.1% DMSO) or DTIC or Compound 6 for 24 h at different concentrations as indicated. The propidium iodide stained cells were analyzed for the distribution of cell cycle by FACS calibur, and the percentage of distribution at different phases of cell cycle was determined using ModFIT software. Data are shown as one representative of at least three independent experiments.
FIG. 6 represents photomicrographs showing invaded B16F0 cells in control (A), 100 μg/ml of DTIC (B), and Compound 6 (C) treated cultures. Bar diagram (D) represents the average number of invaded cells counted from 20 independent fields observed at 20× objective.
FIG. 7 represents immunoblot image showing down-regulation of VEGF protein in Compound 6 treated B16F0 cells. Bar diagram represents the normalized expression of VEGF protein in arbitrary units. Each bar represents the average expression calculated from at least three independent experiments.
FIG. 8 shows inhibitory effect of Compound 6 on human endothelial cell migration. Microphotographs illustrate the migration of HUVECs in the presence of either DTIC (25 and 50 μg/ml at panels B and C, respectively) or Compound 6 (25 and 50 μg/ml at panel E and F, respectively). Panels A and D represent cellular migration in 0.1% DMSO treated vehicle control wells. The bar graph shows the number of migrated cells under different culture conditions as indicated under each bar. Each bar represents mean of migrated cells calculated from at least twenty fields under 20× objective.
FIG. 9 shows inhibition of capillary-like tube formation by Compound 6. Human umbilical vein endothelial cells (HUVECs) were laid on Cultrex coated plates in presence of either DTIC (25 and 50 μg/ml at panels B and C, respectively) or Compound 6 (25 and 50 μg/ml at panels E and F, respectively) and allowed to form endothelial capillary tubes for 16 h at 37° C. Panels A and D represent capillary-like tube formation in 0.1% DMSO treated vehicle control wells.
FIG. 10 shows efficacy of Compound 6 and DTIC against B16F0 tumor growth in C57B61 mice in vivo. The upper panel shows the photographs representing the size of tumors excised from sacrificed animals included in vehicle control (A and D), groups treated with 50 and 100 mg/kg of DTIC (B and C) and groups treated with 50 and 100 mg/kg of Compound 6 (E and F), respectively. Lower panel, table represents the average tumor weight in the respective groups (n=6) as indicated. Percent inhibition of tumor growth achieved in each group was calculated in comparison with the vehicle control group.
These and other embodiments of the present invention will become evident upon reference to the following detailed examples and attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
Melanoma to date is considered a chemotherapy resistant and very hard to treat. Currently, dacarbazine and temozolamide have been extensively used chemotherapeutic agents for treating metastatic malignant melanoma. However, the success rate is low and the side effects are high.
The metastatic malignant melanoma is continued to be an incurable disease with median survival of approximately 8 months and the probability of surviving 5 years after the diagnosis is less than 5%. Response rates to combination regimens are reproducibly higher than with standard dacarbazine. However, in order to unequivocally make a difference in the management of metastatic malignant melanoma, it is necessary to demonstrate significant efficacy for the drug alone first to achieve higher percentage of complete remission (CR). Only then, any other combination dose regimens involving chemotherapeutic drugs, interleukins, interferons, and like biological response modifiers would make the malignant melanoma treatment more manageable and controlled.
Therefore, in order for the dose regimen to be effective, possibly high melanin binding moieties such as lipophillic thiophene system could offer a therapeutic treatment having all the three biochemical mechanisms of action superior to DTIC (Dacarbazine) with positive outcome leading to significantly increase in obtaining complete responses.
So the molecular structure we have chosen initially for our strategy involved a five membered heterocyclic thiophene ring system, which resembles and occupies similar shape and size to phenyl ring and is lipophilic in nature. In addition, thiophene ring structure has additional advantages internally built in that would aid in increasing the efficacy of the molecule by itself.
Thus, the present invention aims to fulfill this unmet medical need of selectively binding to the targeted melanoma cells and sparing the normal cells thereby increasing the target to non-target cell ratio and further providing other related advantages as described herein.
Accordingly, in an effort to increase the melanin binding, initially several compounds involving heterocyclic thiophene ring system as a backbone were considered. Due to the presence of large size sulfur atom, the five membered thiophene ring system would attain similar size and shape to a lipophillic six membered phenyl ring system in space. The substituted thiophene ring system, thus, in addition to it's aromatic nature would offer resonance delocalization of electrons in the ring which may contribute to increased efficacy. Hence, in a test mode of a few thiophene based triazene analogs were synthesized and evaluated with DTIC for their efficacy in vitro. Because of better in vitro efficacy than DTIC of the initially designed compounds, characterizations involving in vivo efficacy and mode of actions were further evaluated. The novel triazene analogs of the present invention, compositions containing the same, and the uses of the analogs and compositions in therapeutic applications is described herein below.
For the purpose of the present invention, the phrase/expression ‘thiophene triazene analogs’ ‘melanin binding analogs’ ‘novel analogs’ are used herein below interchangeably throughout the text referring to compounds of formula I and Formula II.
The compounds of formula (I) and (II) of the present invention, thiophene triazene analogs, having high affinity for melanin, thereby enhancing efficacy more efficiently. Furthermore, in a preferred embodiment, the novel analogs of the present invention may have been specifically designed to bind melanin more efficiently such that target to non-target ratio can be enhanced thereby decreasing the toxicity.
In one embodiment, the melanin binding analogs may be represented by the following:
Wherein,
R is independently selected from H, CH 3 , CH 2 OH
R 1 is independently selected from OH, NHR 4 , NR 4 R 5 , SH
At least one of R 2 , and R 3 is selected from H, N═N—N(CH 3 ) 2 . N═N—NHCH 3 , N═N—N(CH 3 )CH 2 OH, CONHR 4 , CONR 4 R 5 , CONHNH 2 , CONHNHR 4 , CONHNR 4 R 5 , COOCH 3 , COOCH 2 CH 3 , COOH, COSH, CN, C≡CH, SO 2 NH 2 , SO 2 NHR 4 , SO 2 NR 4 R 5 , SO 3 H, SO 2 CH 3 , SO 2 CH 2 CH 2 NH 2 , NHCH 2 COOH, NHCH(CH 3 )COOH, NO 2 , CF 3 , Cl, Br, F, I, CCl 3 , Ph (C 6 H 5 ), CH 3 , C 2 H 5 , n-C 3 H 7 , iso-C 3 H 7 , n-C 4 H 9 , iso-C 4 H 9 , tert-C 4 H 9 , OH, OCH 3 , NH 2 , NHCH 3 , etc. electron withdrawing and electron donating groups.
R 4 and R 5 are independently selected from H, C 1 -C 10 alkyl, alkenyl, alkylol, alkylamine, etc.
X, Y, and Z are independently selected from C, N, O, and S such that the resulting five membered ring systems of the heterocyclic aromatic moieties are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
In another embodiment, the present invention also provides compounds of the formula (II):
Wherein,
At least one of R 1 , and R 2 is independently selected from H, N═N—N(CH 3 ) 2 N═N—NHCH 3 , N═N—N(CH 3 )CH 2 OH, CONH 2 , CONHR 4 , CONR 4 R 5 , CONHNH 2 , CONHNHR 4 , CONHNR 4 R 5 , COOCH 3 , COOCH 2 CH 3 , COOH, COSH, CN, C≡CH, SO 2 NH 2 , SO 2 NHR 4 , SO 2 NR 4 R 5 , SO 3 H, SO 2 CH 3 , SO 2 CH 2 CH 2 NH 2 , NHCH 2 COOH, NHCH(CH 3 )COOH, NO 2 , CF 3 , Cl, Br, F, I, CCl 3 , Ph (C 6 H 5 )CH 3 , C 2 H 5 , n-C 3 H 7 , iso-C 3 H 7 , n-C 4 H 9 , iso-C 4 H 9 , tert-C 4 H 9 , OH, OCH 3 , NH 2 , NHCH 3 , etc. electron withdrawing and electron donating groups.
R 4 and R 5 are independently selected from H, CH 3 , C 1 -C 10 alkyl, alkenyl, alkylol, alkylamine, etc.
X, Y, and Z are independently selected from C, N O, and S such that the heterocyclic aromatic five membered ring of the fused bicyclic systems are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole. The compound of general formula (II) is not 3-methylthiopheno[3,2-d]1,2,3-triazin-4-one (X═Y═C; Z═S; R 1 ═R 2 ═H).
It is to be understood that the invention covers all combinations of particular embodiments of the invention as described herein above, consistent with the definition of the compounds of formula (I) and formula (II).
Some of the preferred thiophene triazene analogs of formula (I) and formula (II) according to the present invention, but not limited to are:
3-[(Dimethylamino)diazenyl]thiophene-2-carboxamide (compd. No. 1) 3-[(Dimethylamino)diazenyl]-4-bromothiophene-2-carboxamide (compd. No. 2) 3-[(Dimethylamino)diazenyl]-5-nitrothiophene-2-carboxamide (compd. No. 3) 4-[(Dimethylamino)diazenyl]-3-methoxythiophene-2,5-dicarboxamide (compd. No. 4) 3-[(Dimethylamino)diazenyl]-5-phenylthiophene-2-carboxamide (compd. No. 5) 3-[(Dimethylamino)diazenyl]thiophene-2-carboxylic acid (compd. No. 6) 3-[(Dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylic acid (compd. No. 7) 3-[(Dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylic acid (compd. No. 8) {3-[(Dimethylamino)diazenyl](2-thienyl)}-N-(2-hydroxyethyl)-carboxamide (compd. No. 9) {3-[(Dimethylamino)diazenyl](2-thienyl)}-N-methylcarboxamide (compd. No. 10) N-(2-Aminoethyl){3-[(dimethylamino)diazenyl](2-thienyl)}-carboxamide (compd. No. 11) 4-[Dimethylamino)diazenyl]thiophene-2-carboxamide (compd. No. 12) 4-[(Dimethylamino)diazenyl]thiophene-3-carboxamide (compd. No. 13) Potassium salt of 3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid (compd. No. 14) 3-Methylthiopheno[2,3-d]1,2,3-triazin-4-one (compd. No. 15) 3-Methyl-6-nitrothiopheno[2,3-d]1,2,3-triazin-4-one (compd. No. 16) 6-Amino-3-methylthiopheno[2,3-d]1,2,3-triazin-4-one (compd. No. 17) 3-Methyl-6-phenylthiopheno[3,2-d]1,2,3-triazin-4-one (compd. No. 18)
In the present invention, the compounds of the formulae (I) and (II) are disclosed together because of their structural similarities. For example, the inactive compound of formula (I) upon in vivo activation by liver microsomal enzymes (cytochrome P450) followed by oxidative demethylation, affords active monomethyltriazene analog. Likewise, the compound of formula (II) upon in vivo hydrolysis affords similar monomethyltriazene analog of the enzymatically active species that derived from formula (I). Therefore, due to the similarities of their metabolites in vivo, in one embodiment, compound of formula (I) was disclosed, and in an another embodiment, compound of formula (II) were disclosed. Thus, the compounds of formula (I) and formula (II) are disclosed due to convenience and should be considered structurally similar due to biological reasons.
Synthesis of Triazene Analogs
According to another feature of the present invention, there is provided a process as shown in the schemes, for the preparation of triazene analogs of the general formula (I) and formula (II), wherein all the groups are as defined earlier.
Compounds (1-8) of the general formula (I) can be produced according to the following method as shown in scheme A
Diazotization of methyl 3-aminothiophene-2-carboxylate or its precursors with sodium nitrite followed by treatment with dimethylamine provides methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate or its derivatives in good yield. Treatment of the above esters with ammonia gave the triazene analogs of formula (I) (3-[(dimethylamino)diazenyl]thiophene-2-carboxamide (compd No. 1), compd. No. 2, compd. No. 3, compd. No. 4, compd. No. 5).
Hydrolysis of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate or its derivatives with aqueous sodium hydroxide in methanol provided the triazene acid analogs of formula (I) (Compd. No. 6, compd. No. 7 and compd. No. 8).
The precursor compounds used in scheme A were produced in the following manner: Methyl 3-amino-4-bromothiophene-2-carboxylate is prepared by the bromination of methyl 3-aminothiophene-2-carboxylate (Aldrich).
Nitration of methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate ( 30 ) gave methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate, which was then methylated using dimethyl sulfate to produce methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate. Reduction of nitro group with iron and HCl gave methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate. Methyl 3-amino-5-phenylthiophene-2-carboxylate is prepared by the known procedure ( 31 , 32 ).
Compounds (9-11) of the general formula (I) can be produced according to the following method as shown in scheme B
Treatment of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate with various amines such as methyl amine, ethanol amine and ethylenediamine provides the corresponding triazene amide analogs of formula (I) (compd. No. 9, compd. No. 10, and compd. No. 11).
Compound (12) of the general formula (I) can be produced according to the following method as shown in scheme C
Diazotization of methyl 4-aminothiophene-2-carboxylate with sodium nitrite followed by treatment with dimethylamine provides methyl 4-[(dimethylamino)diazenyl]thiophene-2-carboxylate. Treatment of the ester with ammonia gave the required 4-[dimethylamino)diazenyl]thiophene-2-carboxamide (compd. No. 12). The precursor compound, methyl 4-aminothiophene-2-carboxylate is produced from the commercially available thiophene-2-carboxylic acid. The nitration of thiophene-2-carboxylic acid provides an inseparable mixture of 4-nitrothiophene-2-carboxylic acid and 5-nitrothiophene-2-carboxylic acid, which is esterified to get the corresponding esters. The nitro functionality is then reduced to amines using iron powder and the mixture separated by silica gel column chromatography to obtain methyl 4-aminothiophene-2-carboxylate.
Compound (13) of the general formula (I) can be produced according to the following method as shown in scheme D
Diazotization of methyl 4-aminothiophene-3-carboxylate with sodium nitrite followed by treatment with dimethylamine provides methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate. Treatment of the ester with ammonia gave the required 4-[dimethylamino)diazenyl]thiophene-3-carboxamide (compd. No. 13). The methyl 4-aminothiophene-3-carboxylate is produced using known procedures in the prior art ( 33 , 34 , 35 ). Thus addition of methyl acrylate to methyl thioglycolate provided methyl 3-[(methoxycarbonyl)methylthio]propanoate in quantitative yield, which on cyclization in presence of sodium methoxide gave methyl 4-oxo-2,3,5-trihydrothiophene-3-carboxylate. Treatment of methyl 4-oxo-2,3,5-trihydrothiophene-3-carboxylate with hydroxylamine followed by basification with ammonia gave methyl 4-aminothiophene-3-carboxylate.
Compound (14) of the general formula (I) can be produced according to the following method as shown in scheme E
Treatment of 3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid with potassium hydroxide in presence of methanol provided the corresponding potassium salt of triazene analog of formula (I), i.e., compd. No. 14.
Compounds (15-17) of the general formula (II) can be produced according to the following method as shown in scheme F
Diazotization of 2-aminothiophene-3-carboxamide or its derivatives with sodium nitrite in presence of concentrated sulfuric acid produced 3H-thiopheno[2,3-d]1,2,3-triazin-4-one or its derivatives. Methylation of 3H-thiopheno[2,3-d]1,2,3-triazin-4-one or its derivatives with iodomethane in presence of potassium carbonate provided the corresponding triazene analogs of formula (II) (compd. No. 15, or compd. No. 16 or compd. No. 17). 2-Aminothiophene-3-carboxamide is produced from the known procedures in the prior art ( 36 , 37 ) and the nitro derivative is prepared by the treatment of nitration mixture.
Compound (18) of the general formula (II) can be produced according to the following method as shown in scheme G
Diazotization of 3-amino-5-phenylthiophene-2-carboxamide with sodium nitrite in presence of concentrated sulfuric acid produced 6-phenyl-3H-thiopheno[3,2-d]1,2,3-triazin-4-one. Methylation of 6-phenyl-3H-thiopheno[3,2-d]1,2,3-triazin-4-one with iodomethane in presence of potassium carbonate provided the corresponding triazene analog of formula (II), i.e., compd. No. 18.
In another embodiment, the method for the synthesis of triazene analogs of formula (I) comprises the diazotization of the corresponding amine compounds using metal nitrate and an acid; the resulting diazotized product may be reacted with amines in presence of a base; finally the triazene ester may be converted to a carboxylic acid or a carboxylic amide.
The method for the synthesis of triazene analogs of formula (I), wherein metal nitrate used in diazotization step is selected from sodium nitrite or potassium nitrite and acid is selected from inorganic acid or organic acid. The inorganic acid may be hydrochloric acid, sulfuric acid, and the like and the organic acid may be benzoic acid, para-toluenesulfonic acid and the like.
The method for the synthesis of triazene analogs of formula (I), wherein the diazotized product may be reacted with amine and the amine is selected from primary amine such as methyl amine, ethyl amine etc., or secondary amine such as dimethyl amine, diethyl amine etc.
The method for the synthesis of triazene analogs of formula (I), wherein the analog of carboxylic acid may be produced by the hydrolysis of the corresponding ester using metal hydroxide in presence of a solvent. The metal hydroxide may be selected from sodium hydroxide or potassium hydroxide etc., and the solvent is selected from water, methanol, ethanol, or mixtures thereof.
The method for the synthesis of triazene analogs of formula (I), where the analog of carboxamide may be produced by the treatment of the corresponding ester with amine in presence of a base in a solvent at ambient temperature. The amine may be selected from ammonia, methyl amine, ethanol amine, ethylene diamine etc., and the base is selected from potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, pyridine, triethyl amine etc., and the solvent is selected from tetrahydrofuran, methanol, ethanol, acetone, water or mixtures thereof.
In another embodiment, the present invention encompasses pharmaceutically acceptable salts of the compounds of the formula (I), and formula (II), for example organic or inorganic acid addition salts. The triazene analogs of the above formula (I) and formula (II) and derivatives thereof, may be in the form of a solvate or a pharmaceutically acceptable salt, e.g., an acid addition or base addition salt. Such salts include hydrochloride, sulfate, phosphate, citrate, fumarate, methanesulfonate, acetate, tartrate, maleate, lactate, mandelate, succinate, oxalate, amino acids, and other suitable salts known in the art.
In another embodiment, the invention encompasses the optical enantiomers or diastereomers of the optically active compounds of formula (I), and formula (II).
Compositions Containing Triazene Analogs
The present invention provides a pharmaceutical or veterinary composition (hereinafter, simply referred to as a pharmaceutical composition) that may contain a melanin targeted analog as described above, in admixture with a pharmaceutically acceptable carrier or diluents. The invention provides a pharmaceutical composition that may contain a melanin targeted analog as described above, in admixture with a pharmaceutically acceptable carrier or diluent.
The pharmaceutical compositions of the present invention may be in any form which allows for the composition to be administered to a subject. For example, the composition may be in the form of a solid, liquid or gas (aerosol). Typical routes of administration include, without limitation, oral, topical, parenteral, sublingual, and rectal. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. Pharmaceutical compositions of the invention are formulated so as to allow the active ingredients contained therein to be bioavailable upon administration of the composition to a subject. Compositions that will be administered to a subject take the form of one or more dosage units, where for example, a tablet may be a single dosage unit, and a container of triazene in topical form may hold a plurality of dosage units.
Materials used in preparing the pharmaceutical compositions should be pharmaceutically pure and non-toxic in the amounts used. It will be evident to those of ordinary skill in the art that the optimal dosage of the active ingredient(s) in the pharmaceutical composition will depend on a variety of factors. Relevant factors include, without limitation, the type of subject (e.g., human), the particular form of the active ingredient, the manner of administration and the composition employed.
In general, the pharmaceutical composition may include a melanin targeted analog or derivative thereof as described herein, in admixture with one or more carriers. The carrier(s) may be particulate, so that the compositions are, for example, in tablet or powder form. The carrier(s) may be liquid, with the compositions being, for example oral syrup or injectable liquid. In addition, the carrier(s) may be gaseous, so as to provide an aerosol composition useful in e.g., inhalatory administration.
When intended for oral administration, the composition is preferably in either solid or liquid form, where semi-solid, semi-liquid, suspension and gel forms are included within the forms considered herein as either solid or liquid.
As a solid composition for oral administration, the composition may be formulated into a powder, granule, compressed tablet, pill, capsule, chewing gum, water or the like form. Such a solid composition will typically contain one or more inert diluents or edible carriers. In addition, one or more of the following adjuvants may be present: binders such as carboxymethylcellulose, ethyl cellulose, microcrystalline cellulose, or gelatin; excipients such as starch, lactose or dextrins, cyclodextrins, disintegrating agents such as alginic acid, sodium alginate, primogel, corn starch and the like; lubricants such as magnesium stearate or sterotex; glidants such as colloidal silicon dioxide; sweetening agents such as sucrose or saccharin, a flavoring agent such as peppermint, methyl salicylate or orange flavoring, and a coloring agent.
When the composition is in the form of a capsule, e.g., a gelatin capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or a fatty oil.
The composition may be in the form of a liquid, e.g., an elixir, syrup, solution, emulsion or suspension. The liquid may be for oral administration or for delivery by injection, as two examples. When intended for oral administration, preferred composition contain, in addition to the present compounds, one or more of a sweetening agent, preservatives, dye/colorant and flavor enhancer. In a composition intended to be administered by injection, one or more of a surfactant, preservative, wetting agent, dispersing agent, suspending agent, buffer, stabilizer and isotonic agent may be included.
The liquid pharmaceutical composition of the invention, whether they be solutions, suspensions or other like form, may include one or more of the following adjuvants: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils such as synthetic mono or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfate; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. Physiological saline is a preferred adjuvant. An injectable pharmaceutical composition is preferably sterile.
A liquid composition intended for either parenteral or oral administration should contain an amount of the triazene analog of formula (I) and/or formula (II) such that a suitable dosage will be obtained. Typically, this amount is at least 0.1% of a compound of the invention in the composition. When intended for oral administration, this amount may be varied to be between 0.1 and 80% of the weight of the composition. Preferred oral compositions contain between 4% and about 50% of the active triazene compound. Preferred compositions and preparations according to the present invention are prepared so that a parenteral dosage unit contains at least 0.01% to 1% by weight of triazene analogs of formula (I) and/or formula (II).
The pharmaceutical composition may be intended for topical administration, in which case the carrier may suitably comprise a solution, emulsion, ointment or gel base. The base, for example, may comprise one or more of the following: petrolatum, lanolin, polyethylene glycols, beeswax, mineral oil, diluents such as water and alcohol, and emulsifiers and stabilizers. Thickening agents may be present in a pharmaceutical composition for topical administration. If intended for transdermal administration, the composition may include a transdermal patch or ionophoresis device. Topical formulations may contain at least 0.1 to about 10% w/v (weight per unit volume) concentration of the triazene analogs of formula (I) and/or formula (II).
The composition may be intended for rectal administration, in the form, e.g., of a suppository which will melt in the rectum and release the drug. The composition for rectal administration may contain an oleaginous base as a suitable nonirritating excipient. Such bases include, without limitation, lanolin, cocoa butter and polyethylene glycol.
The composition may include various materials which modify the physical form of a solid or liquid dosage unit. For example, the composition may include materials that form a coating shell around the triazene analogs of formula (I) and/or formula (II). The materials which form the coating shell are typically inert, and may be selected from, for example sugar, shellac, and other enteric coating agents. Alternatively, the triazene analogs of formula (I) and/or formula (II) may be encased in a gelatin capsule.
The pharmaceutical composition of the present invention may consist of gaseous dosage units, e.g., it may be in the form of an aerosol. The term aerosol is used to denote a variety of systems ranging from those of colloidal nature to systems consisting of pressurized packages. Delivery may be by a liquefied or compressed gas or by a suitable pump system which dispenses the triazene analogs of formula (I) and/or formula (II). Aerosols of compounds of the invention may be delivered in monophasic, biphasic, or triphasic systems in order to deliver the triazene analogs of formula (I) and/or formula (II). Delivery of the aerosol includes the necessary container, activators, valves, sub-containers, spacers and the like, which together may form a kit. Preferred aerosols may be determined by one skilled in the art, without undue experimentation.
In another embodiment, a pharmaceutical composition of the present invention comprising a compound of formula (I) and/or formula (II) or pharmaceutically acceptable salt thereof, and at least one chemotherapeutic agent and optionally a pharmaceutically acceptable diluent or carrier.
The composition as said above, wherein said chemotherapeutic agent is selected from the group consisting of dacarbazine (DTIC), temozolamide, methotrexate, doxorubicin, cytoxan, 5-fluorouracil, cis-platin, carboplatin, oxaliplatin, vincristine, vinblastine, etoposide, irinotecan, topotecan, paclitaxel, docetaxel, taxotere, taxol, tamoxifen, gefitinib, adriamycin, gemcitabine, melphalan, streptozocin, floxuridine, 6-mercaptopurine, bleomycin, daunorubicin, Mitomycin-C, amsacrine, procabazine, capecitabine, avastin, herceptin, bexxar, velcade, zevalin, xeloda, erbitux (cetuximab), rituximab, campath (Alemtuzumab) and the like.
A composition intended to be administered by injection can be prepared by combining the triazene analogs of formula (I) and/or formula (II) with water so as to form a solution. A surfactant may be added to facilitate the formation of a homogeneous solution or suspension. Surfactants are compounds that non-covalently interact with the triazene analog or derivative so as to facilitate dissolution or homogeneous suspension of the triazene analogs of formula (I) and/or formula (II).
An effective amount of a compound or composition of the present invention is used to treat diseases of cells having melanoma and other cancers. These cells are typically mammalian cells. Methods of administering effective amounts of the triazene analogs of formula (I) and/or formula (II) are well known in the art and include the administration of inhalation, oral or parenteral forms. Such dosage forms include, but are not limited to, parenteral solutions, tablets, capsules, sustained release implants and transdermal delivery systems; or inhalation dosage systems employing dry powder inhalers or pressurized multi-dose inhalation devices. The dosage amount and frequency are selected to create an effective level of the agent without harmful effects. It will generally have a dosage range of about 0.01 to 100 mg/kg/day for efficacy, and typically about 2 to 10 mg/kg/day where administered orally or intravenously and about 0.1 to 4 mg/kg/day where administered intranasally or by inhalation.
A pharmaceutical composition comprising at least one compound of formula (I) and/or formula (II) or pharmaceutically acceptable salt thereof, and at least one chemotherapeutic agent and at lest one biologic response modifying agent and optionally a pharmaceutically acceptable diluent or carrier.
The composition containing at least one biologic response modifying agent as said above, wherein said biologic response modifying agent is selected from the group consisting of monoclonal antibodies, interferons (interferon-γ), interleukins (IL-1, IL-2, IL-9, IL-11, IL-12), various types of colony stimulating factors (CSF, GM-CSF, G-CSF), TNF-α receptor blocker drugs (TNF-α), and the like.
Kits Containing Triazene Analogs, and Preparation and Uses Thereof
In another embodiment of the invention, a triazene analog as described above may be included in a kit for producing a triazene analog of the invention (melanin targeted analog) for pharmaceutical use. Such kits generally will be used in hospitals, clinics or other medical facilities with ready access on a daily basis to formulate such formulations.
A method for inhibiting cancer cell growth or killing cancer cell in a patient by administering to said patient a therapeutically effective amount of compounds of formula (I) and formula (II).
A method of treating a subject suffering from cancer disease, wherein said cancer disease is of any type (solid, liquid, and lymphatic origin), and not limited to metastatic malignant melanoma, lymphomas (Hodgkins and non-Hodgkins), sarcomas (Ewing's sarcoma), carcinomas, brain tumors, central nervous system (CNS) metastases, gliomas, breast cancer, prostate cancer, lung cancer (small cell and non-small cell), colon cancer, pancreatic cancer, Head and Neck cancers, oropharyngeal squamous cell carcinoma, comprising the step of administering to said subject, an effective amount of compounds of formula (I) and/or formula (II).
A method for inhibiting cancer cell growth or killing cancer cell in a patient as said above, wherein a cancer cell is originated from any part of the body, and not limited to any organ of human body such as brain, lung, adrenal glands, pituitary gland, breast, prostate, pancreas, ovaries, Gastro Intestinal Tract, kidneys, Liver, spleen, testicles, cervix, upper, lower, or middle esophagus either primary or secondary tumors of all types.
A method of administration of compounds of formula (I) and formula (II) to a patient by any mode of delivery, but not limited to intraperitoneal (IP), intravenous (IV), oral (PO), intramuscular (IM), intracutaneous (IC), intradermal (ID), intrauterine, intrarectal and the like.
A method of administration of compounds of formula (I) and/or formula (II) using nanoparticles of different sizes in an emulsion to a patient, in need thereof.
Anti-Tumor Activity
We assessed the anti-tumor potential of triazene analogs of formula (I) and formula (II). The cell proliferation assay based on MTT incorporation in A2058 cell showed that the triazene analogs of formula (I) and formula (II) exhibit better efficacy in inhibition of tumor cell proliferation when compared to DTIC (Table 1). The 50% inhibitory concentration (IC 50 ) of some of the triazene analogs of the formula (I) and formula (II) were found to exhibit better activity when compare to that shown by standard drug (DTIC).
Similarly, the compound 6 of formula (I) showed better anti-tumor activity than DTIC in B16 F0 melanoma xenograft model of C57B6J mice. In addition, compound 6 also showed dose response inhibition at the two dose levels tested. However, DTIC failed to show statistically significant dose response at the same two dose levels tested ( FIG. 10 ). The failure of DTIC to demonstrate dose response is consistent with the literature reports, indicating that DTIC is an angiogenesis promoter, while our finding indicated that compound 6 is an angiogenesis inhibitor ( FIGS. 7 , 9 ).
The present invention is provided by the examples given below, which are provided by the way of illustration only, and should not be considered to limit the scope of the invention. Variation and changes, which are obvious to one skilled in the art, are intended to be within the scope and nature of the invention, which are defined in the appended claims.
EXAMPLES
Example 1
Synthesis of 3-[(dimethylamino)diazenyl]thiophene-2-carboxamide (Compound 1)
Step a:
Methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate: To a solution of methyl 3-aminothiophene-2-carboxylate (0.5 g, 3.18 mmol) and conc. HCl (1.3 mL, 12.73 mmol) in H 2 O (7.5 mL) was added NaNO 2 (0.24 g, 3.50 mmol) in portions for 5 min at 0° C. After stirring for 0.5 h at 0-5° C., the reaction mixture was added to the solution of K 2 CO 3 (1.66 g, 12.09 mmol) and dimethylamine (1.3 mL, 40%, 11.46 mmol) in H 2 O (9 mL) at 0° C. The mixture was stirred at 0-5° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×30 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (80:20) as eluents to give the product as pale orange color solid (600 mg, 88%), mp 74-76° C. 1 H NMR (400 MHz, CDCl 3 ): δ 7.33 (1H, d, J=5.6 Hz), 7.24 (1H, d, J=5.6 Hz), 3.87 (3H, s), 3.52 (3H, s), 3.29 (3H, s); LC-MS (positive ion mode): m/z 214 (M+H) + .
Step b:
3-[(Dimethylamino)diazenyl]thiophene-2-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (20 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (600 mg) in THF (5 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and the precipitated solid was filtered and dried to give crude product, which was chromatographed over silica gel column using chloroform-methanol (98:2) as eluents to give the product as an off-white solid (400 mg, 72%), mp 168-170° C. IR (neat) ν max 3337, 3172, 2923, 1636, 1599, 1348, 1219, 1117, 884, 771 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 8.28 (2H, br s), 7.35 (1H, d, J=5.6 Hz), 7.31 (1H, d, J=5.6 Hz), 3.58 (3H, br s), 3.20 (3H, br s); LC-MS (positive ion mode): m/z 221 (M+Na) + .
Example 2
Synthesis of 3-[(dimethylamino)diazenyl]-4-bromothiophene-2-carboxamide (Compound 2)
Step a:
Methyl 3-amino-4-bromothiophene-2-carboxylate: To a solution of methyl 3-aminothiophene-2-carboxylate (1 g, 6.36 mmol) in acetic acid (10 mL) was added a solution of bromine (0.32 mL, 6.36 mmol) in acetic acid (1 mL) slowly for 5 min at rt and stirred at the same temperature for 16 h. The reaction mixture was poured into ice cold water and extracted with chloroform (3×100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (95:5) as eluents to give the product as a pale yellow color solid (0.5 g, 33%), mp 58-60° C.
1 H NMR (400 MHz, CDCl 3 ): δ 7.29 (1H, s), 5.63 (2H, br s), 3.85 (3H, s).
Step b:
Methyl 3-[dimethylamino)diazenyl]-4-bromothiophene-2-carboxylate: To a solution of methyl 3-amino-4-bromothiophene-2-carboxylate (0.5 g, 2.11 mmol) and cone. HCl (0.85 mL, 8.47 mmol) in H 2 O (5 mL) was added NaNO 2 (160 mg, 2.33 mmol) in portions for 5 min at 0° C. After stirring 0.5 h at (0-5° C.), the reaction mixture was added to the solution of K 2 CO 3 (1.1 g, 8.04 mmol) and dimethylamine (0.85 mL, 40%, 7.6 mmol) in H 2 O (6 mL) at 0° C. The mixture was stirred at 0-10° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×30 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (90:10) as eluents to give the product as a pale orange color oil (0.5 g, 81%). 1 H NMR (400 MHz, CDCl 3 ): δ 7.38 (1H, s), 3.80 (3H, s), 3.53 (3H, br s), 3.28 (3H, br s).
Step c:
3-[(Dimethylamino)diazenyl]-4-bromothiophene-2-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (10 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-4-bromothiophene-2-carboxylate (500 mg) in THF (5 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and extracted with ethyl acetate (3×50 mL). The combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (98:2) as eluents to give the product as an off-white solid (250 mg, 53%), mp 194-196° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.85 (1H, s), 7.75 (1H, br s), 7.56 (1H, br s), 3.56 (3H, br s), 3.21 (3H, br s); LC-MS (positive ion mode): m/z 277, 279 (M+H) + .
Example 3
Synthesis of 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxamide (Compound 3)
Step a:
Methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate: To a solution of methyl 3-aminothiophene-2-carboxylate (2.0 g, 12.7 mmol) and conc. HCl (5 mL, 50.8 mmol) in H 2 O (30 mL) was added NaNO 2 (0.96 g, 14.08 mmol) in portions for 5 min at 0° C. After stirring 0.5 h (0-5° C.), the reaction mixture was added to the solution of K 2 CO 3 (6.65 g, 48.26 mmol) and dimethylamine (5.14 mL, 40%, 45.7 mmol) in H 2 O (36 mL) at 0° C. The mixture was stirred at 0-10° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×100 mL). The combined layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (80:20) as eluents to give the product as a pale orange color solid (2.5 mg, 91%), mp 74-76° C.
Step b:
Methyl 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylate: Methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (2 g, 9.38 mmol) was added slowly for 15 min at 0 to −5° C. to concentrated sulfuric acid (20 mL). Then concentrated nitric acid (0.54 mL, 70%, 10.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h and rt for 16 h. The mixture was poured into ice cooled water and basified with ammonium hydroxide. The solution was extracted with chloroform (3×100 mL) and the combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-ethyl acetate (80:20) as eluents to give the product as a yellow color solid (450 mg, 26%), mp 128-130° C.
Step c:
3-[(Dimethylamino)diazenyl]-5-nitrothiophene-2-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (35 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylate (400 mg) in THF (10 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-ethyl acetate (50:50) as eluents to give the product as a yellow color solid (90 mg, 26%), mp 240-246° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 8.22 (1H, s), 8.05 (1H, s), 7.91 (1H, s), 3.63 (3H, s), 3.26 (3H, s); LC-MS (positive ion mode): m/z 266 (M+Na) + .
Example 4
Synthesis of 4-[(dimethylamino)diazenyl]-3-methoxythiophene-2,5-dicarboxamide (Compound 4)
Step a:
Methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate: Methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate (5 g, 23.14 mmol) was added slowly for 15 min at 0 to −5° C. to concentrated sulfuric acid (25 mL). Then concentrated nitric acid (3.2 mL, 70%, 34.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h. The mixture was poured into ice cooled water and extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product as a yellow color semi-solid (1.2 g, 20%).
Step b:
Methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate: To a solution of methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (650 mg, 2.5 mmol) in acetone (20 mL) was added potassium carbonate (0.68 g, 5 mmol) at it Dimethyl sulfate (0.36 mL, 3.73 mmol) was added to the above reaction mixture slowly with stirring and a catalytic amount of KI was added. The mixture was refluxed for 4 h and the cooled reaction mixture was filtered and the solids were washed with acetone. Acetone was removed under reduced pressure and the residue was chromatographed over silica gel column using hexane-ethyl acetate (90:10) as eluents to give the product as a pale yellow color solid (0.3 g, 45%), mp 80-82° C. 1 H NMR (400 MHz, CDCl 3 ): δ 4.08 (3H, s), 3.94 (3H, s), 3.92 (3H, s).
Step c:
Methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate: To a solution of methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (0.9 g, 3.27 mmol) in methanol (20 mL) was added conc. Hydrochloric acid (0.3 mL). To the above solution was added iron powder (0.91 g, 16.36 mmol) followed by an aqueous solution of ammonium chloride (0.87 g, 16.3 mmol, water: 5 mL) at rt. The reaction mixture was stirred and warmed to 70° C. for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with ethyl acetate (4×100 mL). The combined organic layer was washed with brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as a pale yellow color solid (0.65 g, 81%), mp 120-124° C. NMR (400 MHz, CDCl 3 ): δ 5.39 (2H, br s), 4.01 (3H, s), 3.87 (3H, s), 3.85 (3H, s); LC-MS (positive ion mode): m/z 246 (M+H) + .
Step d:
Methyl 3-[dimethylamino)diazenyl]-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate: To a solution of methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate (0.6 g, 2.44 mmol), conc. HCl (1 mL, 9.8 mmol) in H 2 O (10 mL) and acetone (10 mL) was added NaNO 2 (0.19 g, 2.7 mmol) in portions for 5 min at 0° C. After stirring for 0.5 h at (0-5° C.), the reaction mixture was added to the solution of K 2 CO 3 (1.28 g, 9.3 mmol) and dimethylamine (1 mL, 40%, 8.78 mmol) in H 2 O (8 mL) at 0° C. The mixture was stirred at 0-10° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×100 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (80:20) as eluents to give the product as pale orange color oil (0.45 g, 62%). 1 H NMR (400 MHz, CDCl 3 ): δ 3.93 (3H, s), 3.88 (3H, s), 3.82 (3H, s), 3.53 (3H, br s), 3.26 ( 31 - 1 , br s); LC-MS (positive ion mode): m/z 324 (M+Na) + .
Step e:
4-[(Dimethylamino)diazenyl]-3-methoxythiophene-2,5-dicarboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (20 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate (400 mg) in THF (5 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and extracted with ethyl acetate (10×50 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was crystallized from chloroform-methanol to give the product as an off-white color solid (80 mg, 22%), mp 226-228° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.86 (1H, s), 7.81 (1H, s), 7.73 (1H, s), 7.35 (1H, s), 3.72 (3H, s), 3.59 (3H, br s), 3.21 (3H, br s); LC-MS (positive ion mode): m/z 294 (M+Na) + .
Example 5
Synthesis of 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxamide (Compound 5)
Step a:
3-Chloro-3-phenylprop-2-enenitrile: To an ice cold (0-5° C.) solution of dry dimethylformamide (25.6 mL, 333.2 mmol) was added phosphorous oxychloride (15.6 mL, 166.6 mmol) dropwise with stirring for 15 min. To this cold mixture, acetophenone (10 g, 83 mmol) was added dropwise maintaining the temperature of the reaction mixture between 45-55° C. for 10 min. The reaction mixture was slowly allowed to rt and stand for 30 min. To the reaction mixture, 7 mL of a total solution of hydroxylamine hydrochloride (23.1 g, 333.2 mmol) in dry DMF (33 mL) was added and the mixture was stirred at 70-80° C. for 5 min. Then the remaining solution of hydroxylamine hydrochloride in DMF was added thereafter at such a rate that the temperature of the reaction mixture rise above 145-155° C. After completion of the addition, the reaction mixture was allowed to rt for 30 min and diluted with cold water (0.5 L). The solution was extracted with chloroform and the chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel using hexane-ethyl acetate (98:2) as eluents to give the product as an oil (7 g, 52%). 1 H NMR (400 MHz, CDCl 3 ): δ 7.64-7.67 (2H, m), 7.43-7.53 (3H, m), 6.02 (1H, s).
Step b:
Methyl 3-amino-5-phenylthiophene-2-carboxylate: To a solution of methyl thioglycolate (1 g, 9.43 mmol) in methanol (5 mL) was added a solution of sodium methoxide (0.5 g, 9.43 mmol) in methanol (5 mL) and stirred for 0.5 h. To the above mixture, a solution of 3-chloro-3-phenylprop-2-enenitrile (1.22 g, 7.5 mmol) in DMF (3.5 mL) was added dropwise for 10 min at rt and stirred the mixture at 60° C. for 2 h. Then, a solution of sodium methoxide (1 g, 18.6 mmol) in methanol (10 mL) was added dropwise at rt and stirring was continued for 2 h at 60° C. The mixture was allowed to rt and poured into cold water and stirred for 15 min. The solution was extracted with chloroform (3×100 mL) and the combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel using hexane-ethyl acetate (92:8) as eluent to give the product as a pale yellow color solid (1.1 g, 50%), mp 130-132° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.62-7.65 (2H, m), 7.38-7.48 (3H, m), 7.00 (1H, s), 4.29 (2H, br s), 3.74 (3H, s); LC-MS (positive ion mode): m/z 234 (M+H) + .
Step c:
Methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate: To a solution of methyl 3-amino-5-phenylthiophene-2-carboxylate (5 g, 21.4 mmol) and conc. HCl (9 mL, 85.8 mmol) in H 2 O (51 mL) was added acetone (30 mL) to dissolve the product. Then NaNO 2 (1.7 g, 23.6 mmol) was added in portions for 15 min at 0° C. After stirring at 0-5° C. for 1 h, the reaction mixture was added to the solution of K 2 CO 3 (11.2 g, 81.5 mmol) and dimethylamine (8.5 mL, 40%, 77.2 mmol) in H 2 O (60 mL) at 0° C. The mixture was stirred at 0-5° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×100 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (90:10) as eluents to give the product as a pale brown color solid (3.8 g, 76%), mp 92-94° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.78-7.80 (2H, m), 7.64 (1H, s), 7.46-7.52 (3H, m), 3.84 (3H, s), 3.60 (3H, s), 3.28 (3H, s); LC-MS (positive ion mode): m/z 290 (M+H) + .
Step d:
3-[(Dimethylamino)diazenyl]-5-phenylthiophene-2-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (80 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate (2.2 g) in THF (15 mL) for 5 min followed by catalytic amount of PEG-400 and the mixture was stirred at rt for 36 h. The solution was poured into ice cooled water and extracted with chloroform. The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (94:6) as eluents to give the product. The crude product was recrystallized from chloroform-hexane to give the product as a yellow color solid (170 mg, 8%), mp 220-222° C. IR (neat) ν max , 3343, 2922, 2855, 1642, 1595, 1221, 1023, 880, 841 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 8.30 (1H, br s), 7.64-7.66 (2H, m), 7.53 (1H, s), 7.30-7.41 (3H, m), 6.34 (1H, br s), 3.59 (3H, s), 3.20 (3H, s); 13 C NMR (100 MHz, CDCl 3 ): δ 164.7, 151.1, 146.7, 133.9, 128.9, 128.5, 125.8, 125.4, 114.7, 43.6, 36.5; LC-MS (positive ion mode): m/z 297 (M+Na) + .
Example 6
Synthesis of 3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid (Compound 6)
To a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (200 mg, 0.93 mmol) in methanol (10 mL) was added a solution of sodium hydroxide (93 mg, 2.3 mmol) in water (2 mL) and stirred at rt for 2 h. The mixture was diluted with ice cold water and acidified with dil. HCl and extracted with chloroform. The combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-ethyl acetate (80:20) as eluents to give the product as an off-white solid (70 mg, 38%), mp 108-110° C. IR (neat) ν max 3402, 3082, 2923, 1708, 1218, 1116, 1066, 1016, 880, 773 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 12.21 (1H, s), 7.47 (1H, d, J=5.2 Hz), 7.30 (1H, d, J=5.2 Hz), 3.65 (3H, s), 3.28 (3H, s); LC-MS (positive ion mode): m/z 200 (M+H) + .
Example 7
Synthesis of 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylic acid (Compound 7)
To a solution of methyl 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylate (550 mg) in methanol (10 mL) was added an aqueous solution of sodium hydroxide (0.25 g in 5 mL of water) at rt and stirred the mixture for 14 h. Excess of methanol was evaporated under reduced pressure and the residue was diluted with ice cold water. The solution was acidified with dil. HCl and the solid separated was filtered, washed with water and dried to give the product as a yellow color solid (450 mg, 86%). The crude product was recrystallized from chloroform-methanol (290 mg), mp 184-186° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 13.26 (1H, br s), 8.00 (1H, s), 3.59 (3H, s), 3.25 (3H, s); LC-MS (positive ion mode): m/z 245 (M+H) + .
Example 8
Synthesis of 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylic acid (Compound 8)
To a solution of methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate (1.8 g, 6.22 mmol) in methanol (50 mL) was added a solution of sodium hydroxide (1.24 g, 31.1 mmol) in water (15 mL) and stirred at rt for 16 h. The mixture was diluted with ice cold water and acidified with dil. HCl. The mixture was stirred for 30 min and the precipitated solid was filtered, washed with water and dried. The solid was chromatographed over silica gel column using hexane-ethyl acetate (70:30) as eluents to give the product. The crude solid was recrystallized from hexane-chloroform to give the product as a pale pink color solid (1.1 g, 61%), mp 162-166° C. IR (neat)ν max . 2923, 2853, 1708, 1260, 1220, 1173, 1042, 1020, 879, 836 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 12.15 (1H, br s), 7.58-7.60 (2H, m), 7.44 (1H, s), 7.32-7.40 (3H, m), 3.65 (3H, s), 3.25 (3H, s); 13 C NMR (100 MHz, CDCl 3 ): δ 162.8, 153.3, 149.7, 133.3, 129.1, 129.0, 125.9, 120.1, 113.4, 44.3, 37.0; LC-MS (positive ion mode): m/z 298 (M+Na) + .
Example 9
Synthesis of {3-[(dimethylamino)diazenyl] (2-thienyl)}-N-(2-hydroxyethyl)-carboxamide (Compound 9)
To an ice cold (0-5° C.) solution of ethanol amine (5 mL) in THF (5 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (500 mg) in THF (5 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and the solution was extracted with ethyl acetate (3×50 mL). The combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product, which was recrystallized from chloroform-hexane gave the product as a pale orange color solid (430 mg, 77%), mp 118-122° C. IR (neat) ν max , 3397, 3278, 2926, 1621, 1353, 1298, 1220, 1083, 1007, 882, 775 cm −1 ;
1 H NMR (400 MHz, CDCl 3 ): δ 8.86 (1H, br s), 7.31 (1H, d, J=5.6 Hz), 7.28 (1H, d, J=5.2 Hz), 3.78-3.82 (2H, m), 3.60-3.64 (2H, m), 3.57 (3H, br s), 3.23 (3H, br s), 2.76 (1H, t, J=5.0 Hz); LC-MS (positive ion mode): m/z 243 (M+H) + .
Example 10
Synthesis of {3-[(dimethylamino)diazenyl](2-thienyl)}-N-methylcarboxamide (Compound 10)
To an ice cold (0-5° C.) solution of methyl amine (3 mL) in THF (5 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (500 mg) in THF (5 mL) for 5 min and stirred at rt for 36 h. The solution was poured into ice cooled water and the solution was extracted with chloroform (3×100 mL). The combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (98:2) as eluents to give the product, which was recrystallized from chloroform-hexane gave the product as a pale orange color solid (380 mg, 76%), mp 98-102° C. IR (neat) ν max 3297, 3082, 2929, 1637, 1380, 1348, 1299, 1221, 1109, 1016, 882, 776 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 8.35 (1H, br s), 7.29 (1H, d, J=5.2 Hz), 7.27 (1H, d, J=5.2 Hz), 3.57 (3H, br s), 3.21 (3H, br s), 3.00 (3H, d, J=4.8 Hz); LC-MS (positive ion mode): m/z 213 (M+H) + .
Example 11
Synthesis of N-(2-aminoethyl){3-[(dimethylamino)diazenyl](2-thienyl)}-carboxamide (Compound 11)
To an ice cold (0-5° C.) solution of ethylenediamine (5 mL) in ethanol (5 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (250 mg) in ethanol (5 mL) for 5 min and stirred at rt for 24 h. The solution was poured into ice cooled water and saturated with sodium chloride. The solution was extracted with THF (3×100 mL). The combined THF layer was washed with brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (90:10) as eluents to give the product as an off-white solid (60 mg, 22%), mp 98-100° C. 1 H NMR (400 MHz, CDCl 3 ): δ 8.65 (1H, br s), 7.30 (1H, d, J=5.2 Hz), 7.28 (1H, d, J=5.2 Hz), 3.50-3.57 (5H, m). 3.24 (3H, br s), 2.91 (2H, t, J=6.0 Hz).
Example 12
Synthesis of 4-[dimethylamino)diazenyl]thiophene-2-carboxamide (Compound 12)
Step a:
4-Nitrothiophene-2-carboxylic acid: Sulfuric acid (3.0 mL, 5.505 g, 56.17 mmol) was added to nitric acid (2.0 mL, 2.98 g, 49.6 mmol) slowly at 0-10° C. After completion of the addition, thiophene-2-carboxylic acid (2.8 g, 21.87 mmol) was added to the above nitration mixture slowly for 15 min at the same temperature and stirred the mixture for 1 h. The reaction mixture was poured into ice cold water and stirred for 30 min. The precipitated solid was filtered, washed with cold water and dried. The filtrate was extracted with ethyl acetate. The combined ethyl acetate layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The combined product was stirred with hexane (2×50 mL) and filtered the solid and dried to give the product as an off-white solid (2.8 g, 75%), mp 110-118° C. The product was a mixture of two compounds by HPLC and 1 H NMR and was proceeded to the next step.
Step b:
Methyl 4-nitrothiophene-2-carboxylate: To a solution of nitrothiophene-2-carboxylic acids (6.8 g, 39.3 mmol) in methanol (50 mL) was added thionyl chloride (6 mL, 78.6 mmol) drop wise under stirring at rt. The reaction mixture was refluxed for 2 h and attained to rt. The mixture was poured into ice cooled water and stirred for 15 min. The precipitated solid was filtered, washed with cold water and dried to give the product as an off-white solid (6.2 g, 85%). 1 H NMR showed that, it is a mixture of two compounds and the crude product was proceded to the next step.
Step c:
Methyl 4-aminothiophene-2-carboxylate: To a solution of methyl nitrothiophene-2-carboxylates (7 g, 37.43 mmol) in a mixture of water (150 mL) and methanol (50 mL) was added Conc. hydrochloric acid (4.5 mL). To the above solution was added iron powder (10.5 g, 188 mmol) followed by ammonium chloride (10 g, 187 mmol) at rt. The reaction mixture was stirred and warmed to 70° C. for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with chloroform (4×100 mL). The combined organic layer was dried over sodium sulfate and filtered. Solvent was evaporated and the residue was chromatographed over silica gel column using hexane-ethyl acetate (90:10 and small amount of triethyl amine) as eluent to give methyl 4-aminothiophene-2-carboxylate (1.8 g, 31%), mp 76-78° C. 1 H NMR (400 MHz, CDCl 3 ): δ 7.31 (1H, d, J=1.6 Hz), 6.40 (1H, d, J=1.6 Hz), 3.85 (3H, s), 3.63 (2H, br s). Further elution of the column with the same solvent system provided methyl 5-aminothiophene-2-carboxylate (0.5 g, 8.5%), mp 70-72° C. 1 H NMR (400 MHz, CDCl 3 ): δ 7.45 (1H, d, J=4.0 Hz), 6.09 (1H, d, J=4.0 Hz), 4.29 (2H, br s), 3.81 (3H, s).
Step d:
Methyl 4-[(dimethylamino)diazenyl]thiophene-2-carboxylate: To a solution of methyl 4-aminothiophene-2-carboxylate (1.7 g, 10.82 mmol) and cone. HCl (4.6 mL, 43.5 mmol) in H 2 O (20 mL) was added NaNO 2 (0.84 g, 12.17 mmol) in portions for 5 min at 0° C. After stirring for 0.5 h at 0-5° C., the reaction mixture was added to the solution of K 2 CO 3 (5.8 g, 42 mmol) and dimethylamine (4.6 mL, 40%, 40.9 mmol) in H 2 O (30 mL) at 0° C. The mixture was stirred at 0-5° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×100 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (80:20) as eluents to give the product as light red color solid (250 mg), which was recrystallized from chloroform-hexane (110 mg), mp 90-92° C. 1 H NMR (400 MHz, CDCl 3 ): δ 7.93 (1H, d, J=1.6 Hz), 7.31 (1H, d, J=1.6 Hz), 3.88 (3H, s), 3.31 (6H, br s).
Step e:
4-[Dimethylamino)diazenyl]thiophene-2-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (5 mL) was added a solution of methyl 4-[(dimethylamino)diazenyl]thiophene-2-carboxylate (110 mg) in THF (2 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and extracted with chloroform. The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (99:1) as eluents to give the product as pale red color solid (60 mg, 60%), mp 128-130° C. IR (neat) ν max 3372, 3189, 1648, 1609, 1219, 1120, 1088, 865, 772 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 7.68 (1H, d, J=1.2 Hz), 7.28 (1H, d, J=1.2 Hz), 6.18 (2H, br s), 3.29 (6H, br s); LC-MS (positive ion mode): m/z 199 (M+H) + .
Example 13
Synthesis of 4-[(dimethylamino)diazenyl]thiophene-3-carboxamide (Compound 13)
Step a:
Methyl 3-[(methoxycarbonyl)methylthio]propanoate: Methyl acrylate (4.25 g, 49.5 mmol) was added dropwise over 20 min to a stirred solution of methyl thioglycolate (5 g, 47.16 mmol) and piperidine (0.10 mL) at rt. When about half of the acrylate had been introduced, more piperidine (0.10 mL) was added. After completion of the addition of the acrylate, the reaction mixture was stirred for 1 h at rt. The mixture was diluted with 100 mL of chloroform. The chloroform layer was washed with water, brine and dried over Na 2 SO 4 . The solution was filtered and evaporated the solvent to give the product as an oil (9 g, 100%).
Step b:
Methyl 4-oxo-2,3,5-trihydrothiophene-3-carboxylate: To a stirred slurry of sodium methoxide (1.68 g, 31.25 mmol) in dry THF (15 mL) was added a solution of dimethyl 3-thiahexanedioate (5 g, 26.03 mmol) in THF (10 mL) at rt for 5 min. The reaction mixture was heated at reflux for 2 h, cooled to rt and poured into ice cold water and acidified with dil. HCl. The solution was extracted with chloroform and the combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (95:5) as eluents to give the product as pale yellow color oil (1.6 g, 39%).
Step c:
Methyl 4-aminothiophene-3-carboxylate hydrochloride: A mixture of 4-oxo-3-methoxycarbonyltetrahydrothiophene (6.5 g, 40.62 mmol), hydroxylamine hydrochloride (2.84 g, 40.62 mmol) and acetonitrile (30 mL) was stirred under reflux for 1 h. The mixture was then cooled and the solid which separated was filtered off and washed with dry ether to afford the title compound (4.9 g, 62%), mp 192-196° C.
Step d:
Methyl 4-aminothiophene-3-carboxylate: Methyl 4-aminothiophene-3-carboxylate hydrochloride (290 mg) was dissolved in water (20 mL) and basified with ammonia solution. The solution was extracted with chloroform and the combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as pale yellow color oil (150 mg, 65%). 1 H NMR (400 MHz, CDCl 3 ): δ 7.92 (1H, d, J=3.6 Hz), 6.08 (1H, d, J=3.6 Hz), 4.79 (2H, br s), 3.85 (3H, s).
Step e:
Methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate: To a solution of methyl 4-aminothiophene-3-carboxylate (200 mg, 1.27 mmol) and cone. HCl (0.5 mL, 5.09 mmol) in H 2 O (5 mL) was added NaNO 2 (96 mg, 1.39 mmol) in portions for 5 min at 0° C. After stirring for 0.5 h at 0-5° C., the reaction mixture was added to the solution of K 2 CO 3 (665 mg, 4.8 mmol) and dimethylamine (0.5 mL, 40%, 4.57 mmol) in H 2 O (5 mL) at 0° C. The mixture was stirred at 0-5° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×30 mL). The combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (90:10) as eluents to give the product as pale red color oil (20 mg, 8%). 1 H NMR (400 MHz, CDCl 3 ): δ 8.00 (1H, d, J=2.8 Hz), 6.97 (1H, d, J=3.6 Hz), 3.85 (3H, s), 3.34 (6H, br s).
Step f:
4-[(Dimethylamino)diazenyl]thiophene-3-carboxamide: To an ice cold (0-5° C.) solution of ammonium hydroxide (5 mL) was added a solution of methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate (110 mg) in THF (2 mL) for 5 min and stirred at rt for 36 h. The solution was poured into ice cooled water and extracted with chloroform. The combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (98:2) as eluents to give the product as a pale red color solid (25 mg, 25%), mp 168-172° C. IR (neat) ν max 3324, 3125, 2917, 2851, 1655, 1600, 1367, 1336, 1090 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 8.55 (1H, br s), 8.19 (1H, d, J=3.6 Hz), 7.15 (1H, d, J=3.6 Hz), 5.84 (1H, br s), 3.56 (3H, br s), 3.19 (3H, br s); LC-MS (positive ion mode): m/z 199 (M+H) + .
Example 14
Synthesis of potassium salt of 3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid (Compound 14)
To a solution of 3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid (example 4: 300 mg, 1.50 mmol) in methanol (15 mL) was added a solution of potassium hydroxide (84 mg, 1.50 mmol) in methanol (5 mL) at rt and the mixture stirred at the same temperature for 1 h. The solution was filtered to remove any impurities and evaporated under reduced pressure to get the compound as a brown color solid (290 mg, 81%), mp 274-280° C. 1 H NMR (400 MHz, D 2 O): δ 7.36 (1H, d, J=5.6 Hz), 7.10 (1H, d, J=5.6 Hz); LC-MS (positive ion mode): m/z 238 (M+H) + .
Example 15
Synthesis of 3-methylthiopheno[2,3-d]-1,2,3-triazin-4-one (Compound 15)
Step a:
2-Aminothiophene-3-carboxamide: To a solution of 2,5-dihydroxy-1,4-dithiane (10 g, 65.78 mmol) in ethanol (200 mL) and triethylamine (2 mL) was added cyanoacetamide (5.52 g, 65.78 mmol) at rt for 5 min. The reaction mixture was refluxed for 3 h and attained to rt. Ethanol (appr. 150 mL) was removed under reduced pressure and poured the contents into ice cold water and stirred for 15 min. The solution was extracted with ethyl acetate (3×100 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product as a pale yellow color solid (4.9 g, 53%), mp 150-152° C.
Step b:
3H-Thiopheno[2,3-d]1,2,3-triazin-4-one: To an ice cold solution (0° C.) of 2-aminothiophene-3-carboxamide (5 g, 35.21 mmol) in concentrated sulfuric acid (40 mL) was added a cold (0° C.) solution of sodium nitrite (2.5 g, 35.21 mmol) in concentrated sulfuric acid (30 mL) for 30 min (while adding, the temperature should keep between −5-0° C.). After addition, the mixture was stirred at the same temperature (0° C.) for 3 h. The mixture was poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min. The solution was extracted with ethyl acetate (4×200 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product as a pale red color solid (1.0 g, 18%), mp 175-176° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 15.18 (1H, s), 8.16 (1H, d, J=5.6 Hz), 7.64 (1H, d, J=5.6 Hz); 13 C NMR (100 MHz, DMSO-d 6 ): δ 159.1, 153.8, 132.0, 126.1, 121.2; LC-MS (negative ion mode): m/z 152 (M−H) − .
Step c:
3-Methylthiopheno[2,3-d]1,2,3-triazin-4-one: To a solution of 3H-thiopheno[2,3-d]1,2,3-triazin-4-one (80 mg, 0.522 mmol) in acetone (50 mL) was added sequentially potassium carbonate (144 mg, 1.04 mmol), iodomethane (0.04 mL, 0.627 mmol) and potassium iodide (catalytic) at rt and the mixture was stirred at rt for 3 h. The solution was filtered and the solids were washed with acetone. Acetone was evaporated under reduced pressure, diluted with ice cold water and stirred for 10 min. The solution was extracted with chloroform (4×75 mL) and the combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-ethyl acetate (90:10) as eluents to give the product as an off-white solid (50 mg, 57%), mp 104-108° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 8.17 (1H, d, J=5.6 Hz), 7.64 (1H, d, J=5.6 Hz), 3.95 (3H, s); 13 C NMR (100 MHz, CDCl 3 ): δ 159.4, 153.9, 130.7, 125.6, 121.7, 37.3.
Example 16
Synthesis of 3-methyl-6-nitrothiopheno[2,3-d]1,2,3-triazin-4-one (Compound 16)
To an ice cold (−10° C.) solution of concentrated sulfuric acid (5 mL) was added 3-methylthiopheno[2,3-d]1,2,3-triazin-4-one (0.6 g, 3.6 mmol) for 10 min., nitric acid (0.4 mL, 9 mmol) was added to the above reaction mixture for 5 min and the mixture was attained to rt and stirred for 1 h. The mixture was poured into ice cold water and stirred for 15 min. The precipitated solid was filtered and purified by silica gel column chromatography using hexane-chloroform (1:1) as eluents to give the product as a pale yellow color solid (390 mg, 51%), mp 164-168° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 8.60 (1H, s), 3.99 (3H, s).
Example 17
Synthesis of 6-amino-3-methylthiopheno[2,3-d]1,2,3-triazin-4-one (Compound 17)
To a solution of 3-methyl-6-nitrothiopheno[2,3-d]1,2,3-triazin-4-one (1.25 g, 5.9 mmol) in methanol (50 mL) was added conc. Hydrochloric acid (0.6 mL). To the above solution was added iron powder (1.67 g, 29.5 mmol) followed by a solution of ammonium chloride (1.57 g, 29.5 mmol) in water (10 mL) at rt. The reaction mixture was stirred and warmed to 70 for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with ethyl acetate (4×100 mL). The combined organic layer was dried over sodium sulfate and filtered. Solvent was evaporated and the residue was chromatographed over silica gel column using hexane-ethyl: acetate (60:40) as eluents to give the product as a pale yellow color solid (80 mg, 7.5%), mp 190-194° C. 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.40 (2H, s), 6.11 (1H, s), 3.82 (3H, s); LC-MS (negative ion mode): m/z 181 (M−H) − .
Example 18
Synthesis of 3-methyl-6-phenylthiopheno[3,2-d]1,2,3-triazin-4-one (Compound 18)
Step a:
3-Amino-5-phenylthiophene-2-carbonitrile: To a suspension of sodium sulfide (0.95 g, 12.23 mmol) in DMF (12.5 mL) was added a solution of 3-chloro-3-phenylprop-2-enenitrile (2 g, 12.23 mmol) in DMF (5 mL) at rt for 5 min and stirred the mixture at 60-70° C. for 2 h. Then chloroacetonitrile (0.77 mL, 12.23 mmol) was added dropwise to the reaction mixture and again stirred at 60-70° C. for 2 h. Then, a solution of sodium methoxide (0.66 g, 12.23 mmol) in methanol (5 mL) was added dropwise and stirring was continued for 1 h at the same temperature. The mixture was allowed to rt and poured into cold water and stirred for 15 min. The solid separated was filtered, washed with water and dried. The solid was recrystallized from hexane-chloroform to give the product as a pale brown color solid (150 mg, 8%), nip 158-160° C. 1 H NMR (400 MHz, CDCl 3 ): δ 7.52-7.54 (2H, m), 7.37-7.41 (3H, m), 6.75 (1H, s), 4.48 (2H, s); LC-MS (negative ion mode): m/z 199 (M−H) − .
Step b:
3-Amino-5-phenylthiophene-2-carboxamide: To a suspension of 3-amino-5-phenylthiophene-2-carbonitrile (150 mg) in aqueous sodium hydroxide solution (20 mL, 10%) was added ethanol (10 mL) and the mixture was refluxed for 1 h. The reaction mixture was allowed to attain rt and the crystals separated were filtered off, washed with cold water and dried to give the product as a golden yellow color solid (70 mg, 45%), mp 180-182° C.
1 H NMR (400 MHz, CDCl 3 ): δ 7.56-7.58 (2H, m), 7.33-7.41 (3H, m), 6.79 (1H, s), 5.68 (1H, s), 5.21 (1H, s); LC-MS (positive ion mode): m/z 241 (M+Na) + .
Step c:
6-Phenyl-3H-thiopheno[3,2-d]1,2,3-triazin-4-one: To an ice cold solution (0° C.) of 3-amino-5-phenylthiophene-2-carboxamide (0.37 g, 1.7 mmol) in concentrated sulfuric acid (20 mL) was added a cold (0° C.) solution of sodium nitrite (120 mg, 1.86 mmol) in concentrated sulfuric acid (8 mL) for 10 min (while adding, the temperature should keep between −5-0° C.). After addition, the mixture was stirred at 0° C. for 1 h and at rt for 1 h. The reaction mixture was cooled and poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min. The solution was extracted with ethyl acetate (3×50 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as an off-white color solid (200 mg, 39%), my 178-180° C. 1 H NMR (400 MHz, CDCl 3 ): δ 12.30 (1H, br s), 7.86 (1H, s), 7.73-7.75 (2H, m), 7.49-7.54 (3H, m); LC-MS (negative ion mode): m/z 228 (M−H) − .
Step d:
3-Methyl-6-phenylthiopheno[3,2-d]1,2,3-triazin-4-one: To a solution of 6-phenyl-3H-thiopheno[3,2-d]1,2,3-triazin-4-one (250 mg, 1.1 mmol) in acetone (25 mL) was added sequentially potassium carbonate (300 mg, 2.18 mmol), iodomethane (0.08 mL, 1.31 mmol) and potassium iodide (catalytic) at rt and the mixture was stirred at rt for 16 h. The solution was filtered and the solids were washed with acetone. Acetone was evaporated under reduced pressure, diluted with ice cold water and stirred for 10 min. The solution was extracted with chloroform (4×75 mL) and the combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:05) as eluents to give the product as a yellow color solid (110 mg, 42%), mp 220-222° C. IR (KBr) ν max 3095, 2924, 1680, 1298, 1248, 1102, 977, 829 cm −1 ; 1 H NMR (400 MHz, CDCl 3 ): δ 7.78 (1H, s), 7.70-7.73 (2H, m), 7.45-7.51 (3H, m), 4.09 (3H, s); 13 C NMR (100 MHz, CDCl 3 ): δ 155.1, 153.8, 153.3, 132.2, 130.2, 129.4, 126.7, 125.4, 119.5, 37.4; LC-MS (positive ion mode): m/z 244 (M+H) + .
Evaluation of Anti-Melanoma Tumor Growth Potential in In Vitro and In Vivo
Example 19
Cell Proliferation Assay Using MTT Based Assay
MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] incorporation based cell proliferation assay was performed using standard procedure with some modifications ( 38 ). The cytotoxic efficacy of the test compounds were evaluated in human malignant melanoma A2058 cells by MTT cell proliferation assay kit (Roche Applied Sciences, Germany). The assay was carried out according to the instruction provided by the vendor. Briefly, equal numbers of cells was plated in 96-well flat-bottomed plates in 100 μl of medium and were exposed to either DTIC or its derivative compounds at various concentrations up to 150 μg/ml for a period of three days. Vehicle control culture wells received only a maximum of 0.5% DMSO. Thereafter, 0.5 mg/ml of MTT reagent was added to each well and the microplate was incubated further for 4 h at 37° C. in presence of 5% CO 2 . Finally, the cells were solubilized by adding solubilizing solution and allowed to incubate at 37° C. overnight. After complete solubilization of the formazan crystals the absorbance was read at 540 nm in a microplate reader (BioRad, USA). The results (mean OD±SD) obtained from quadruplicate wells were used in calculation to determine the inhibition of cell proliferation (50% inhibitory concentration, IC 50 ) of the test compounds.
TABLE 1
Anti-tumor potential of DTIC and its related compounds
in A2058, human malignant melanoma cells
IC 50 in A2058 cells
Test compounds
(μg/mL)
Compound 1
78.701
Compound 2
113.3
Compound 6
53.6
Compound 9
214.2
Compound 10
178.7
Compound 11
164.3
Compound 12
165.01
Compound 13
48.8
Compound 17
146.7
DTIC
68.08
Example 20
Cytotoxicity Using LDH Leakage Assay
From the data obtained from the MTT assay (Table J), compound 1, compound 6 and compound 13 have been selected and their cytotoxicity potential has been further validated in LDH leakage assay. FIG. 1 shows loss of cell viability in terms of percent increase in leaked LDH at different concentrations of DTIC and other test compounds as indicated. Cytotoxicity potential of DTIC and its derivative compounds were evaluated by measuring the leaked lactate dehydrogenase (LDH) into the culture supernatant (LDH Cytotoxicity Detection Roche Applied Sciences, Germany). The leaked LDH is directly proportional to the cell damage done by the cytotoxic compounds. In brief, cells were treated with test compounds at various concentrations and incubated for 48 h. Vehicle control culture wells received only a maximum of 0.5% DMSO. The cell free culture supernatants were mixed with catalyst and dye solution and allowed to incubate for 15 min at room temperature. Finally, the reaction was stopped and the optical density was measured at 492 nm in a microplate reader (BioRad, USA). The results (mean OD±SD) obtained from quadruplicate wells were used in calculation to determine the cytotoxicity potential (50% of inhibitory concentration, IC 50 ) of the test compounds. A plot of loss of cell viability as indicated by the leakage of LDH versus drug concentration is depicted in FIG. 1 .
Example 21
Tumor Selectivity
Next, to check whether the DTIC derivative compounds can selectively kill the melanoma cells without or minimally affecting the normal cells, we assessed the effect of the test compounds on normal human skin epithelial HS.531.sk cells. LDH leakage assay indicate that up to 100 μg/ml dose of DTIC and its derivative compounds do not affect the normal cell skin cell growth. Whereas, 120 μg/ml of DTIC, compound 1, compound 3 and compound 4 caused 5.8%, 4.2%, 2.4%, and 2.4% reduction in normal cell viability, respectively. Therefore, from this observation it is evident that compound 3 and compound 4 possess more selectivity than DTIC to kill melanoma cells without or minimally affecting the normal cells ( FIG. 2 ).
Example 22
Effect of the Triazene Compounds on the Apoptotic Cell Death Potential in A2058 Human Melanoma Cells
Proteolytic cleavage of PARP by caspases is regarded as a hallmark of apoptosis. Caspase-3 cleaves the 113-kDa PARP to generate 89- and 24-kDa polypeptides ( 39 ). Next, with an intention to evaluate the comparative apoptotic potential of DTIC and test products compound 1, compound 6 and compound 13, PARP cleavage assay has been performed on A2058 cells. PARP cleavage was estimated by using Western immunoblot assay as described earlier ( 40 ). FIG. 3 illustrates comparative efficacy of PARP cleavage by the test compounds at a fixed dose of 100 μg/ml. Western blot image shows the expression of cleaved subunit of PARP at 89 kDa in compd. No. 3 treated A2058 cells is 56.6% more than in DTIC treated cells at the same concentration. This observation suggests that compd. No. 3 exhibits better apoptotic cell death potential in A2058 human melanoma cells
Example 23
Comparative Efficacy of Cell Proliferation Inhibition by DTIC And Compound 6 in B16F0 Mouse Melanoma Cells and A375 Human Melanoma Cells
The comparative anti-tumor growth potential of DTIC and Compound 6 was further tested in B16F0 mouse melanoma cells and A375 human melanoma cells by using MTT based cell proliferation assay following the methodology described earlier (Example 19). Briefly, equal numbers of either B16F0 or A375 cells were plated in 96-well flat-bottomed plates in 100 of medium and were treated with either DTIC or Compound 6 at different concentrations for 3 days. Vehicle control culture wells received only a maximum of 0.5% DMSO. After adding the MTT reagent, the cells were solubilized and the intracellular formazan formation was calorimetrically read at 540 nm in a microplate reader (BioRad, USA). The results (mean OD±SD) obtained from quadruplicate wells were used in calculation to determine the inhibition of cell proliferation (50% of inhibitory concentration, IC50) of the test compounds.
TABLE 2
Comparative anti-tumor growth potential of DTIC and Compound
6 in B16F0 mouse melanoma and A375 human melanoma cells
50% of inhibitory concentration,
Test
IC50 (μg/ml) in
compounds
B16 F0 cells
A375 cells
DTIC
360.4
70.1
Compound 6
57.6
46.5
Example 24
Comparative Cytotoxicity Potential of DTIC and Compound 6 On B16F0 Mouse Melanoma Cells and A375 Human Melanoma Cells
Comparative cytotoxicity potential of DTIC and Compound 6 on B16F0 mouse melanoma cells and A375 human melanoma cells were further evaluated by measuring the leaked lactate dehydrogenase (LDH) into the culture supernatant (LDH Cytotoxicity Detection Kit Plus , Roche Applied Sciences, Germany), following the methodology described earlier (Example 20). The results (mean OD±SD) obtained from quadruplicate wells were used in calculation to determine the cytotoxicity potential (50% of inhibitory concentration, IC50) of the test compounds (Table 3).
TABLE 3
Comparative cytotoxicity potential of DTIC and compound
6 in B16F0 mouse melanoma and A375 human melanoma cells
Treatment
% increase in LDH secretion with
Test
concentration
respect to vehicle treated control in
compounds
(μg/ml)
B16 F0 cells
A375 cells
DTIC
100
5.7
246
Compound 6
100
61.5
331
Example 25
Anti-Tumor Efficacy of Compound 1 and Compound 6 in MCF-7 Human Breast Tumor Cells, MIA-PaCa2 Human Pancreas Tumor Cells and DU145 Human Prostate Tumor Cells
Anti-tumor growth potential of Compound 1 and Compound 6 were evaluated in MCF-7 human breast tumor cells, MIA-PaCa2 human pancreas tumor cells and DU145 human prostate tumor cells by using MTT based cell proliferation studies as described earlier (example 19). The results (mean OD±SD) obtained from quadruplicate wells were used in calculation to determine the inhibition of cell proliferation (50% of inhibitory concentration, IC50) of the test compounds (Table 4).
TABLE 4
Comparative anti-tumor growth potentials of DTIC, Compound 1 and
Compound 6 in MCF-7 human breast tumor cells, MIA-PaCa2 human
pancreas tumor cells and DU145 human prostate tumor cells
50% of inhibitory concentration, IC50 (μg/ml)
Test
MIA-
compounds
MCF-7
PaCa2
DU145
DTIC
135.1
202.9
87.2
Compound 1
130.3
168.5
153.2
Compound 6
91.7
81.9
62.6
Example 26
B16 F0 Mouse Melanoma Cell Colony Formation Assay
Clone formation efficiency of the Compound 6 and DTIC was tested by following the procedure described earlier with some modifications ( 41 ). Briefly, B16F0 cells were harvested and seeded into 6-well plates (100 cells/ml). The cells were allowed to grow for 2 days and thereafter, the cells were incubated with DMEM containing either 0.1% DMSO or 100 μg/ml DTIC or 50 μg/ml and 100 μg/ml of Compound 6 for further 8 days. Fresh medium containing test agents was replaced at every 24 h. Finally, the wells were washed three times with PBS and fixed in methanol for 15 min. The cells were stained with Giemsa stain and observed under microscope. The image of the stained wells were captured digitally (Kodak Image Station 4000MM, Carestream Health Inc., New Haven, Conn.) and number of colonies were counted and analyzed by using NIH Image J software. FIG. 4 shows inhibition of B16 colony growth in DTIC and Compound 6 treated wells. Compound 6 exhibited significant inhibition in B16 tumor cell colony growth compared with DTIC. 37.6%, 55.2% and 68.7% growth inhibitions were achieved by 100 μg/ml of DTIC, 50 μg/ml and 100 μg/ml of Compound 6, respectively.
Example 27
Cell Cycle Analysis of Compound 6 Treated B16 F0 Mouse Melanoma Cells
Cell cycle analysis of Compound 6 and DTIC treated B16F0 cells were analyzed by flow cytometry as described earlier with some modifications ( 42 ). Briefly, B16F0 cells were cultivated in DMEM containing 10% fetal bovine serum (FBS) in presence of 4.5 g/l D-glucose. The sub confluent cells were treated with either DTIC or Compound 6 and incubated for 24 h. Cells were harvested and prepared single cell suspension in buffer (PBS+2% FBS). The cells were washed twice with cold PBS and then fixed with cold 70% ethanol for 30 min. Ethanol was removed by centrifugation and the cells were suspended and the cell count was adjusted to 10 6 cells per ml. The cells were washed two times with PBS and then the cells were stained with propidium iodide for 30 min at 37° C. in presence of RNase. Finally, the cells were analyzed on FACS Calibur flow cytometry (BD Biosciences, USA). FIG. 5 depicts the distribution of cells in different phases of cell cycle modulated by DTIC and Compound 6.
Example 28
B16F0 Mouse Melanoma Cell Invasion Assay
The inhibitory effects of DTIC and compound 4 on In vitro invasive ability of B16F0 were tested in cell invasion assay performed with by using Matrigel (BME Cultrex®, R&D Systems, USA) coated cell culture inserts (Becton Dickinson, USA) with 8 μm-pore membrane. Equal number (fifty thousands) of B16F0 cells were applied in each insert well and allowed to attach for 2 h at 37° C. and in presence of 5% CO 2 . Thereafter, the cellular invasion through the matrigel layer was performed in presence or absence of test compounds. Either 100 μg/ml of DTIC or Compound 6 was applied in the lower chamber of the invasion assembly. 0.1% DMSO was applied in the vehicle control culture chambers. After 24 h treatment, the matrigel layer containing cells was removed with cotton plug and the invaded cells on the other side of the membrane were fixed with methanol for 5 min and then stained with Giemsa. The stained membrane was mounted on a glass slide and number invaded cells were counted in 20 random fields (20× objective) under a light microscope (Nikon Eclipse TS 100). Compound 6 significantly reduced malignant tumor cell invasion when compared to vehicle or DTIC in in vitro B16 melanoma cell culture experiment ( FIG. 6 ).
Example 29
Compound 6 Inhibits Vascular Endothelial Growth Factor (VEGF) production B16F0 cells
B16F0 cells were cultivated in Dulbecco's modified Eagle's red medium (DMEM) (Sigma Life Science, USA) containing 10% fetal bovine serum (FBS) and 4.5 g/l D-glucose. Equal number cells (5×10 4 ) were seeded in culture dishes (35×10 mm, 11.7 cm 2 ). The cells were treated with either 50 μg/ml of DTIC or Compound 4 for 24 h. The cells incubated with only 0.1% DMSO was considered as vehicle control. After 24 h, the cell lysates were prepared and analyzed for Vascular Endothelial Growth Factor (VEGF) expression by western blot assay as described earlier with appropriate modifications ( 43 ).
For Western blot analyses, equal amount of B16F0 cell lysate proteins were separated in 12.5% SDS-PAGE under reducing conditions, and transferred onto nitrocellulose membranes (Bio-Rad, USA). The membranes were blocked with SuperBlock (Thermo scientific, USA) and subsequently reacted with VEGF antibody (Abeam, UK) at 4° C. overnight. Bound antibodies were probed with horseradish peroxidase conjugated secondary antibody and the specific immunoreactions were developed with enhanced chemiluminescence (Thermo scientific, USA). The stripped membranes were developed again with anti-actin antibody as an internal loading control. The images of immunoreactive bands were captured in Kodak Image Station 4000MM (Carestream Health Inc., New Haven, Conn.) and analyzed densitometrically by Kodak molecular Imaging software, Version 4.5. FIG. 7 depicts a representative immunoblot image shows down regulation of VEGF protein in Compound 6 treated B16F0 cells.
Example 30
Endothelial Cell Migration Assay
The methodology of endothelial cell migration assay was essentially the same as described earlier with some modifications ( 43 ). FALCON™ Cell Culture inserts (Becton Dickinson, USA) with 8 μm-pores in their PET membrane was coated with 0.1 mg/ml of collagen. Human umbilical vein endothelial cells (HUVEC) were added to the cell culture inserts (Becton Dickinson) at a density of 5×10 4 cells/insert. Cells were allowed to migrate through the insert for 18 h in presence of different concentrations of either DTIC or Compound 6. The control culture containing migration assembly received only 0.1% DMSO. The cells which did not migrate were scrapped off by cotton plug and the migrated cells were fixed with methanol for 5 min and then stained with Giemsa. The membranes of the inserts were then mounted on glass slides. Cells migrated through the membrane pores were counted in 20 random fields under Nikon Eclipse TS 100 microscope at 20× objective. FIG. 8 shows significant inhibition of migration of Compound 6 treated endothelial cells.
Example 31
In Vitro Capillary Formation Assay
In vitro capillary formation assay was performed with Human umbilical vein endothelial cells (HUVEC), cultured on 10 mg/ml basement membrane extract (BME-Cultrex®, R&D Systems, USA) bed. The protocol of in vitro endothelial tube formation assay was the same as described earlier with some modifications ( 44 ). Briefly, four hundred microliters of Cultrex was coated at 4° C. in each well of 24-well culture plate and allowed to gel at 37° C. for 1 h. HUVECs were plated at a density of 7.5×10 4 cells per well with 40 μl of DMEM supplemented with 10% fetal bovine serum and 4.5 g/l D-glucose. The cells were then treated with either DTIC or Compound 6 at desired concentration as indicated for 16 hours. Vehicle control cultures received only 0.1% DMSO. Pictures were taken under a Nikon Eclipse TS 100 microscope equipped with a Nikon Coolpix camera. Compound 6 exhibited inhibition of capillary formation in a dose dependent manner, in contrast, DTIC promoted capillary formation with human endothelial cells in in vitro culture condition ( FIG. 9 ).
Example 32
Anti Tumor Growth Potential of Compound 6 in B16 F0 Melanoma Xenograft Model of C57B6J Mice
In vivo efficacy of compound 6 against melanoma growth was evaluated in B16 F0 melanoma xenograft model of C57B6J mice ( 45 ). C57B6J mice of 6 weeks age (body weight 18-22 g) were purchased from National Institute of Nutrition (NIN), Hyderabad (India). Animals study protocols were approved by Institutional Ethics Committee (IAEC). All the studies were performed in compliance with the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) guidelines and OECD guidelines. Animals were allowed free access to standard feed and provided charcoal filtered and UV exposed water ad libitum. The animals were maintained at a controlled temperature (24-26° C.), humidity (45-70%), and 12 h/12 h of light/dark cycle.
To induce the melanoma tumor formation, sub-confluent B16F0 cells were harvested by brief trypsinization and 1×10 6 cells were injected subcutaneously in 0.2 ml phosphate-buffered saline. Drug treatment was started after development of palpable tumors (3-5 days after implantation of the cells). Drugs were prepared in phosphate-buffered saline (10% DMSO, v/v) and different doses of either DTIC or compound 6 were administered daily through intra-peritoneal route. Vehicle treated control animals received only 10% DMSO. After fourteen days of treatment, the animals were sacrificed by CO 2 inhalation and tumors were excised and weighed. FIG. 10 shows comparative efficacy of inhibiting tumor growth by DTIC and compound 6 at various concentrations in B16 F0 melanoma xenograft model of C57B6J mice.
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The present invention discloses triazene analogs of the general formula (I) and formula (II), their tautomeric forms, stereoisomers, polymorphs, hydrates, solvates, and pharmaceutically acceptable salts thereof for the metastatic malignant melanoma and other cancers including but not limited to lymphomas, sarcomas, carcinomas, and gliomas.
The invention further discloses a process for the preparation of the above said triazene analogs of formula (I) and formula (II), and their pharmaceutically acceptable compositions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-laser driving apparatus and an adjusting method thereof and further to an image-forming apparatus having the multi-laser driving apparatus.
2. Related Background Art
A laser driving control method in the image-forming apparatus using multiple lasers is a feedback method of monitoring amounts of light emitted from laser diodes, from current values of a photodiode and, if necessary, properly adjusting driving currents of the laser diodes with reference to the light amounts.
In this method, adjustment is necessary for uniformizing relations of amounts of the light emitted from the laser diodes to the monitor currents of the photodiode. In the multiple lasers, the monitor currents have delicate difference or variation between the laser diodes, and thus an independent adjusting circuit is given to each of the laser diodes to carry out an adjustment operation individually.
FIG. 7 is a block diagram to explain a laser driving control circuit according to a prior art example.
Reference symbol 1 designates a multi-beam laser, 1 a a laser diode 1 (LD 1 ), 1 b a laser diode 2 (LD 2 ), and 1 c a photodiode (PD) for monitoring amounts of light from LD 1 and LD 2 . In order to control the multi-beam laser 1 , this circuit is comprised of LD 1 drive control circuit 51 and LD 2 drive control circuit 52 .
The operation of the LD 1 drive control circuit 51 will be described schematically. In adjustment of LD 1 , monitor current 1 switch (SW) 8 a and initial adjusting resistor 102 are selected to the LD 1 drive control circuit 51 from a monitor current select signal 7 . The monitor current (Im) outputted from PD passes through a line 4 to be converted to a monitor voltage (Vm) by the initial adjusting resistor 102 , LD 2 final adjusting resistor 9 , and fixed resistor 101 . The monitor voltage is amplified by gain amplifier 10 and thereafter is inputted into a comparator 12 to be compared with the reference voltage a of 11 . Numeral 13 denotes a sample-hold circuit, which charges a hold capacitor 15 when the reference voltage a 11 is greater than the monitor voltage (Vm) in sampling according to a sample-hold signal 14 , but discharges the hold capacitor 15 otherwise. The voltage appearing at the hold capacitor 15 is inputted into a drive amplifier 16 to cause a current set by drive current setting resistor 18 to flow into the collector of drive transistor 17 . When a switching transistor 19 is turned on by a laser modulation signal 21 , it allows the current from the laser diode 1 of 1 a to flow to bring about emission of light. The operation of the LD 2 drive control circuit 3 is similar to that of the LD 1 drive control circuit 2 , and thus description thereof is omitted herein.
In the prior art example described above, the adjustment operation for the multi-beam laser is multiple; for example, in the case of a two-beam laser, the adjustment operation is double that of a single laser. In other words, the adjustment operation has to be carried out for each of single lasers.
Namely, in the case of the structure of the above prior art example, the adjustment had to be carried out in such a manner that for the laser diode 1 the initial adjusting resistor 102 was first adjusted and the final adjusting resistor 9 was adjusted thereafter and that for the laser diode 2 the initial adjusting resistor 105 was first adjusted and the final adjusting resistor 26 was adjusted thereafter.
SUMMARY OF THE INVENTION
The present invention has been accomplished in order to solve the above problem and an object of the present invention is to provide a multi-laser driving apparatus and an adjusting method thereof capable of saving the load of the adjusting step, or an image-forming apparatus having such a multi-laser driving apparatus.
A multi-laser driving apparatus according to the present invention is a laser driving apparatus comprising:
a plurality of laser emitting elements;
a light receiving element for monitoring amounts of light from said laser emitting elements;
current-voltage converting means for converting a light amount monitor current outputted from said light receiving element to a light amount monitor voltage; and
control means for controlling a drive current of each of said plurality of laser emitting elements, based on said light amount monitor voltage outputted from said current-voltage converting means,
wherein said current-voltage converting means comprises a common resistor and a plurality of non-common resistors, said common resistor being connected to said light receiving element and to each of said plurality of non-common resistors, and
wherein each of said non-common resistors is connected to said common resistor through switching means and connected to said control means.
A driving method according to the present invention is a laser driving method in which a light receiving element receives light from a laser emitting element, current-voltage converting means converts a monitor current outputted from the light receiving element to a monitor voltage, and control means controls a drive current of the laser emitting element, based on said monitor voltage,
wherein said current-voltage converting means comprises a common resistor and a non-common resistor and said common resistor together with said non-common resistor, is used for converting said monitor current corresponding to emission of light from each of a plurality of said laser emitting elements, to said monitor voltage, and
wherein the non-common resistor together with said common resistor converts said monitor current of a laser emitting element selected from said plurality of laser emitting elements, to said monitor voltage.
An image-forming apparatus according to the present invention comprises the laser driving apparatus described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a laser driving circuit in an embodiment of the present invention;
FIG. 2 is a graph to show laser driving current versus emission characteristics and monitor current versus emitted light amount characteristics in the embodiment of the present invention;
FIG. 3 is a flowchart to show an adjusting method of the laser driving circuit in the embodiment of the present invention;
FIG. 4 is a first graph to illustrate the adjustment process of the laser driving circuit in the embodiment of the present invention;
FIG. 5 is a second graph to illustrate the adjustment process of the laser driving circuit in the embodiment of the present invention;
FIG. 6 is a schematic diagram to show an image-forming apparatus of the present invention; and
FIG. 7 is a block diagram of the laser driving circuit according to the prior art example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram to explain a laser drive control circuit, which is an embodiment of the present invention.
Reference symbol 1 designates a multi-beam laser, 1 a a laser diode 1 (LD 1 ), 1 b a laser diode 2 (LD 2 ), and 1 c a photodiode (PD) for monitoring amounts of light from LD 1 and LD 2 . For controlling the multi-beam laser 1 , this circuit has an LD 1 drive control circuit 2 and an LD 2 drive control circuit 3 and is comprised of an initial adjusting resistor Rm 1 5 and a fixed resistor Rms 6 which are common to these drive control circuits. The initial adjusting resistor Rm 1 5 is a resistor capable of being set variably at a desired resistance.
The operation of the LD 1 drive control circuit 2 will be described schematically. In the adjustment of LD 1 , monitor current 1 switches (SWs) 8 a , 8 b are selected to the LD 1 drive control circuit 2 from a monitor current select signal 7 . The switch 8 b is connected in a switchable state between the fixed resistor Rms 6 and a final adjusting resistor Rm 2 9 . The monitor current (Im) 4 outputted from PD is converted to a monitor voltage (Vm) by the initial adjusting resistor Rm 1 5 , the LD 2 final adjusting resistor Rm 2 9 , and the fixed resistor Rms 6 . The initial adjusting resistor 5 and fixed resistor 6 are common resistors used for the adjustment operations of both LD 1 and LD 2 . The monitor voltage is then sent to a control means having at least a gain amplifier (amplifying means) 10 , a comparator (comparing means) 12 , and a reference voltage generating means 11 . The monitor voltage is amplified by the gain amplifier 10 and thereafter is inputted into the comparator 12 to be compared with the reference voltage a (Vref) of the reference voltage generator 11 . Numeral 13 denotes a sample-hold circuit, which charges a hold capacitor 15 when the reference voltage a 11 is greater than the monitor voltage (Vm) in sampling according to a sample-hold signal 14 , but discharges the hold capacitor 15 otherwise. The voltage appearing at the hold capacitor 15 is inputted into a drive amplifier 16 to cause the current set by a drive current setting resistor 18 to flow into the collector of a drive transistor 17 . When a switching transistor 19 is turned on by a laser modulation signal 21 , it allows the current from the laser diode 1 of 1 a to flow, thereby effecting emission of light. Since the operation of the LD 2 drive control circuit 3 is similar to that of the LD 1 drive control circuit 2 except that monitor current 2 switches (SWs) 25 a , 25 b are selected to the LD 2 drive control circuit 3 from the monitor current select signal 7 , the description thereof is omitted herein.
In FIG. 1, numeral 24 represents an inverter, 25 monitor current 2 switches (SWs), 26 an LD 2 final adjusting resistor Rm 2 ′, 27 a gain amplifier b, 28 a reference voltage b, 29 a comparator b, 30 a sample-hold circuit b, 31 a sample-hold signal b, 32 a sample-hold capacitor b, 33 a drive amplifier b, 34 a drive transistor b, 35 a drive current setting resistor b, 36 a switching transistor b, 37 a load resistor drive transistor b, 38 a laser modulation signal b, 39 a differential driver b, and 40 a laser load resistor.
[Setting of Adjustment Resistances]
FIG. 2 is a graph to show the laser drive current Iop-emitted light amount L characteristics and the monitor current Im-emitted light amount L characteristics. In the graph, the graph to show the Iop-L characteristics is illustrated on the right side of the axis of L [mW] indicating the emitted light amount L, and the graph to show the Im-L characteristics on the left side of the axis of L [mW]. The relations of current values Iop, Im to emitted light amount L can be approximated each to a linear function. Concerning the monitor current Im-emitted light amount L characteristics, there is delicate variation between the monitor currents for LD 1 and LD 2 at a given light amount, depending upon structures of the laser diodes, i.e., finish conditions of the individual laser diodes. In order to show the variation, two linear functions are graphed on the left side of the axis L [mW] in FIG. 2 .
Let us define a specified light amount value as P and suppose the following.
LD 1 monitor current Im=P/α (1)
LD 2 monitor current Im′=P/β (2)
(where α and β are constants satisfying α≦β)
Then the following relation holds.
Im≧Im′ (3)
The prime mark “′” will be used hereinafter for expressing each of symbols related to LD 2 .
Since the condition is that the feedback loop in the laser current control circuit at the specified light amount is in an equilibrium state, a total set resistance (Rm, Rm′) of the adjusting resistors for each of the laser diode 1 and the laser diode 2 is determined uniquely from the reference voltage value Vref and each monitor current value (Im or Im′).
LD 1 total set resistance Rm=Rm 1 + Rm 2 + Rms (4)
LD 2 total set resistance Rm′=Rm 1 + Rm 2 ′+ Rms (5)
(In Eqs. (4) and (5) Rm 1 and Rms are common and Rm 2 ′ is the final adjusting resistor concerning LD 2 .)
Then the following equations hold.
Rm=Vref/Im=α·Vref/P (6)
Rm′=Vref/Im′=β·Vref/P (7)
Rm≦Rm ′ (∵ α≦β) (8)
In the present invention we assume Rm 1 >Rm 2 and Rm 1 >Rm 2 ′.
On the other hand, giving consideration to the fact that the specified light amount value has a certain width because of variation of optics etc., maximums (Rmmax, Rm′max) are set for the total set resistances of the adjusting resistors. These-maximums need to be set so as to be not less than the resistance at the minimum specified light amount. Let the set maximums of the initial adjusting resistor Rm 1 and the final adjusting resistors for LD 1 , LD 2 be Rm 1 max, Rm 2 max, and Rm′ 2 max and let the monitor currents at the minimum specified light amount be Immin and Im′min, respectively. Then the following relations hold.
Rm max[= Rm 1 max+ Rm 2 max+ Rms]>Vref/Im min (9)
Rm>Vref/Im min
Rm ′max[= Rm 1 max+ Rm ′ 2 max+ Rms]>Vref/Im ′min (10)
Rm>Vref/Im ′min
Rm max≦ Rm ′max (∵ Im min≧ Im ′min)
Likewise, consideration is also given to conditions upon maximum specified emission. Then minimums (Rmmin, Rm′min) are also set for the total set resistances of the adjusting resistors upon the maximum specified emission. These minimums are expressed by the following equations. Supposing these minimums are the fixed resistance Rms, the following relations are derived from the above argument.
Rm min[= Rms]<Vref/Im max (11)
Rm ′min[= Rms]<Vref/Im ′max (12)
Here Immax, Im′max represent the monitor currents at the maximum specified light amount.
Since the fixed resistance Rms is common, the following relation can be derived.
Rm min= Rm ′min= Rms<Vref/Im max≦ Vref/Im ′max (13)
However, since the initial adjusting resistor Rm 1 is common, there occurs a difference ΔR between the resistance after the initial adjustment and each total set resistance (Rm, Rm′). Since the final adjusting resistors (Rm 2 , Rm 2 ′) need to be set at a value enough to absorb the variation of each monitor current, the following equations have to be satisfied.
Rm 2 >Δ R=Vref/Im′−Vref/Im
Rm 2 ′>Δ R=Vref/Im′−Vref/Im
(∵ Im>Im ′) (14)
From the above argument, the setting conditions of the adjusting resistors are as follows.
Rm=Vref/Im=Rm 1 + Rm 2 + Rms
Rm′=Vref/Im′=Rm 1 + Rm 2 ′+ Rms
Vref/Im min< Rm
Vref/Im ′min< Rm′
Rm 1 > Rm 2
Rm 1 > Rm 2 ′
Rm 2 > Vref/Im′−Vref/Im
Rm 2 ′> Vref/Im′−Vref/Im
Rms<Vref/Im max
(∵ Im≧Im ′)
[Adjusting Method]
FIG. 3 is a flowchart to show the adjusting method. The method will be described herein with an example of the adjusting method using LD 1 for the initial adjustment. First, the LD 1 monitor current Im is selected by the monitor current switch SW (S 1 ). Then the initial adjustment is started to adjust the initial adjusting resistor Rm 1 into the specified range; if it is off the specified range it will be adjusted so as to be within the specified range (S 2 , S 3 ). Then the adjustment is focused into the final specified range by the LD 1 final adjusting resistor Rm 2 ; if the resistance is off the final specified range the resistance will be adjusted into the final specified range (S 4 , S 5 ). Then the monitor current switches (SWs) are turned to the LD 2 side (S 6 ). Since the initial adjustment has already been completed in the steps S 2 , S 3 and can be omitted herein, the final adjustment of LD 2 is carried out by the LD 2 final adjusting resistor Rm 2 ′, thereby completing the adjustment (S 7 , S 8 ).
FIG. 4 is a graph to show the relationship between angle step and resistance. In the present embodiment variable resistors of a rotating type, which rotate in steps of equal angles, are used as the adjusting resistors. In that case, an effective rotation angle (full rotation angle) capable of outputting a resistance is represented by θ and a rotation angle upon the initial adjustment (initial adjustment rotation angle) and a rotation angle upon the final adjustment (final adjustment rotation angle) by θint and θend, respectively. A moving angle in each adjustment will be called an angle step. Each adjusting resistor can be varied stepwise by an equal amount both upon the initial adjustment and upon the final adjustment. Angle steps during the respective adjustments will be called an initial angle step ΔS 1 and a final angle step ΔS 2 .
Initial angle step Δ S 1 =θ int/θ
Final angle step Δ S 2 =θ end/θ
In the present invention the initial angle step may be set greater than the final angle step. In other words, the steps may be set so as to satisfy ΔS 1 >ΔS 2 .
A resistance resolution ΔRmINT in the initial adjustment (i.e., a change amount of resistance per single angular change) can be expressed as follows from the set maximum Rm 1 max of the initial adjusting resistor and the initial angle step ΔS 1 .
Δ RmINT=Rm 1 max·Δ S 1
For the adjustments, the adjusting method of gradually increasing the light amount is employed for the purpose of protecting the laser. Then the initial values of the adjusting resistors are started from the maximum. FIG. 5 is a graph to show the relationship between angle step and resistance in the final adjustment. As illustrated in FIG. 5, supposing that the initial adjustment was achieved by the number steps Sn from the initial value of the set resistance into the specified range, the initial adjustment value Rt is given by Rt=Rmmax−ΔRmINT·Sn, where Rmmax is the total resistance of the adjusting resistors. (Reference is made to FIG. 5.)
The resistance resolution ΔRmEND in the final adjustment of LD 1 is expressed as follows from the total resistance Rm 2 max of the final adjusting resistor and the final angle step ΔS 2 .
Δ RmEND=Rm 2 max·Δ S 2
Supposing that the final adjustment of LD 2 was achieved by the number of steps Sm into the specified range, the final adjustment value Rt is given by Rp=Rt−ΔRmEND·Sm from the initial adjustment value Rt. Similarly, the final adjustment value Rp in the final adjustment of LD 1 is given by Rp=Rt+ΔRm′END·Sk, where Sk is the number of required steps and ΔRm′END is the resistance resolution.
FIG. 6 is a diagram to show the sectional structure of an image recording apparatus as an embodiment of the present invention and the structure of a density control device installed therein.
In FIG. 6, numeral 61 denotes a color image-forming unit of the electrophotographic method, 62 a photosensitive drum onto which laser beams are guided to form a latent image, and 63 a transfer drum for transferring an image developed from the latent image onto a recording sheet. Numeral 64 designates a laser scanning unit for emitting the laser light indicating an image signal. Numeral 60 represents a light source unit for emitting multiple beams, described previously, which has at least the laser diodes 1 , 2 , the photodiode (PD), the LD 1 drive control circuit 2 , and the LD 2 drive control circuit 3 illustrated in FIG. 1 . Numeral 70 denotes a polygon mirror and 71 a reflecting mirror. The light source unit 60 may also be set in the laser scanning unit 64 .
Numeral 65 indicates a developing unit for yellow toner which develops a yellow latent image, 66 a developing unit for cyan toner, 67 a developing unit for magenta toner, and 68 a developing unit for black toner. Numeral 69 stands for a density sensor unit for detecting the density of an image formed on the photosensitive drum 62 , 610 for a detecting circuit for detecting a density sensor signal from the density sensor unit 69 , and 611 for a reference voltage circuit for supplying the reference voltage to the signal detecting circuit 610 . Numeral 612 designates a CPU (central processing unit) for executing the control of the whole of this apparatus.
Further, numeral 613 represents a development bias power supply for the yellow developing unit 65 , 614 a development bias power supply for the cyan developing unit 66 , 615 a development bias power supply for the magenta developing unit 67 , and 616 a development bias power supply for the black developing unit 68 .
Described next is the operation of the image recording apparatus having the above structure.
At the color image-forming unit 61 , the sensitive drum 62 , after charged by a charging unit not illustrated, is exposed to the laser light beams emitted form the laser diodes 1 and 2 and projected from the laser scanning unit 64 . The multi-laser beams from the laser scanning unit 64 form a latent image on the surface of the photosensitive drum 62 . The light amounts of the respective multi-laser beams are approximately equal. For example, after formation of the yellow latent image, the yellow development bias power supply 613 is actuated to apply the development bias to the yellow developing unit 65 to visualize the yellow latent image with toner. The toner image thus visualized is attracted by transfer high-voltage power applied to the transfer drum 63 , whereby it is transferred from the photosensitive drum 62 onto the transfer drum 63 .
The above sequential operation is carried out similarly for each of the colors (yellow Y, magenta M, cyan C, and black Bk), whereby a color image is formed on the transfer drum 63 . After that, the color image is transferred onto a transfer sheet (not illustrated) and is then fixed to be printed out.
As apparent from the above series of print sequences, the print sequences of the respective colors are independent of each other in the image recording apparatus, so that the toner densities of the respective colors can be detected by measuring the image on the photosensitive drum 62 or on the transfer drum 63 by the density sensor 69 . Then toner compounding capable of achieving the optimum image quality can be implemented by controlling the recording condition (the bias herein) in each of the recording processes, using this detection result.
In the present embodiment, therefore, the toner image transferred onto the photosensitive drum 62 is measured by a reflected light amount measuring system including the density sensor 69 and densities of the respective color toners are always combined stably.
As described above, the present invention presents the effects of work saving of the adjusting circuits and reduction of the adjustment time in the drive control circuits of the multi-beam laser. There are cases wherein the number of laser beams needs to be increased, for example to 4, in order to further enhance the quality of image, and the effects of work saving and reduction of the adjustment time become further outstanding in such cases.
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A laser driving apparatus which includes a plurality of laser emitting elements, a light receiving element for monitoring amounts of light from the plurality of laser emitting elements, and a current-voltage converter for converting a light amount monitor current outputted from the light receiving element to a light amount monitor voltage. The laser driving apparatus also includes a control circuit for controlling a drive current of each of the plurality of laser emitting elements, based on the light amount monitor voltage outputted from the current-voltage converter. The current-voltage converter includes a common resistor and a plurality of non-common resistors, wherein the common resistor is connected to said light receiving element, and each of the plurality of non-common resistors is connectable to the common resistor through a respective switch and is connected to the control circuit.
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This is a continuation of application Ser. No. 383,651, filed July 30, 1973, now abandoned.
BACKGROUND OF THE INVENTION
It is known that both room temperature and heat curable silicone rubbers have many outstanding properties which make them desirable for industrial applications, however, such cured organopolysiloxanes are extremely difficult to bond to other materials. As a result, an extensive amount of work has been heretofore done in developing primers and other coating materials which can be applied to the surface of the organopolysiloxane to aid in bonding the polysiloxane to other material. (See, for example, U.S. Pat. Nos. 3,455,762; 3,377,309; and 3,619,256.) While some degree of success has been obtained by approaches of this nature, all such approaches have an undesirable cost impact in that they require some additional material. Unfortunately, the characteristics of silicone rubbers that make them desirable for many applications are just the same characteristics that make it difficult for other materials to be bonded to silicone rubber. Further, silicone rubbers are outstandingly resistant to corona discharges, ozone, and high temperature oxygen which are the means by which other relatively inert polymeric materials are treated to increase their surface energy and therefore their bondability to other materials. According to this invention, I have found a technique for treating the surface of silicone rubbers which raises the energy of the surface to the point where it may be bonded directly to a wide variety of liquid crosslinkable polymers and a wide variety of adhesives. The direct bond with the crosslinkable polymers is extremely useful in rocket motor applications and the availability of a wide variety of adhesives will permit a greater choice of materials which may be bonded to the silicone rubber by the adhesives.
It is accordingly an object of this invention to provide a method for treating the surface of a silicone rubber to produce a high energy surface.
It is another object of this invention to provide a method for treating silicone rubbers that improves the bondability of the rubber with a wide variety of materials.
These and other objects of this invention will be readily apparent from the following description of the invention.
DESCRIPTION OF THE INVENTION
Broadly stated, this invention contemplates the raising of the energy of the surface of a silicone rubber by treating the silicone rubber with an aqueous solution of a halogen. The preferred halogen is bromine because its characteristics of solubility in water and reactivity at ambient temperatures fortuitously result in a system which activates the surface of silicone rubbers at rates which are neither too fast nor too slow. In addition, bromine has the advantage of ready storability as an element in the liquid state. Thus, while other halogens may be used if the reaction conditions are adjusted to account for the different degrees of reactivity, this invention will be hereafter described with respect to aqueous solutions of bromine which, for the above reasons, are the preferred embodiments.
This invention is usable with a wide variety of silicone elastomers including graft and block copolymers containing polydimethylsiloxane sequences. The preferred substrates are silicones containing phenyl-Si linkages; these are attacked most rapidly by bromine water yielding brombenzene and a hydroxyl-containing polymer surface. The silicones may either be unfilled or may contain typical fillers such as silica, graphite, glass, boron, silicon carbide and organic particulates or fibers.
The treatment of the silicone rubber surface, according to this invention to increase its energy level, improves the bondability of the silicone rubber with a wide variety of liquid crosslinkable rubbers such as functionally active polybutadienes, polyisobutylenes, polybutadiene-acrylic acid-acrylonitrile-copolymers, as well as a wide variety of adhesive materials such as the polyurethane epoxy, phenolic, unsaturated polyester, melamine-formaldehyde, urea-formaldehyde, alkyd resin, polysulfide, polyaziridine, polyvinyl acetal and cyanoacrylate adhesives, as well as animal and vegetable glues such as casein and hot-melt adhesives. The availability of a wide variety of adhesives will permit the silicone rubbers to be bonded to a wider range of organic and inorganic materials than can now be attained by choosing an appropriate adhesive system which is now known to bond to the material but could not heretofore be bonded to a silicone rubber.
According to the preferred procedure of this invention, the silicone rubber surface is treated in an aqueous solution of bromine at room temperature for 0.1 to ten hours, then is thoroughly washed with water and dried at elevated temperatures. When the silicone rubber surface has been activated to the point where it is usable according to this invention, the original hydrophobic and unreceptive surface becomes wettable with water, receptive to organic dye, such as crystal violet, and absorbent in the infrared at 3400 cm - 1 (attenuated total reflectance, ATR). Thus, a worker skilled in the art can readily determine the conditions necessary for treatment of a wide variety of silicone rubbers according to this invention, by measuring the infrared spectrum of the treated surface, the attraction which the treated surface shows for water, or by observing the affinity which the treated surface shows for organic dyes.
EXAMPLE 1
Discs of Dow Corning 93-104 silicone rubber 0.063 inches thick were mounted on cylindrical steel bases 1.5 inches in diameter. The surfaces of the silicone rubber discs were lightly sandpapered, wiped with toluene and dried overnight in air at 200° F. The silicone rubber specimens were then immersed in a saturated solution of bromine in water for varying lengths of time, washed with water and again dried in air at 200° F. A cylinder of a filled rubber having a matrix of hydroxy functional polybutadiene cured with dimeryl diisocyanate was cast against the silicone rubber surfaces and allowed to cure three days at 140° F and two days at 160° F. Tension was applied perpendicular to the silicone-to-polybutadiene interface by drawing the samples at 0.2 inch/minute at 72° F in an Instron tensiometer. In this test of tensile strength, untreated samples of silicone separate cleanly from the polybutadiene showing that the silicone-to-polybutadiene bonding is much lower in tensile strength than either the polybutadiene or the silicone rubber. However, silicone samples treated with bromine water for several hours bond well enough to the polybutadiene containing material to produce a bond stronger than the polybutadiene-containing material itself and such samples break primarily within the polybutadiene mass. Results of these tests are summarized in Table 1.
TABLE I______________________________________ Breaking Stress, psiBromine Water Polybutadiene-to-SiliconeTreatment, Hours.sup.a) Bond Type of Break______________________________________0 39.5 adhesive failure1 64.2 cohesive failure in polybutadiene3 76.0 cohesive failure in polybutadiene5 93.3 cohesive failure in polybutadiene______________________________________ .sup.a) Silicone surface in a saturated solution of bromine in water at room temperature.
EXAMPLE II
A sheet of Silastic 955 silicone rubber 2 mm in thickness, a product of Dow Corning Corporation, was immersed in saturated bromine water for 10 hours at 23° C, then thoroughly rinsed with distilled water and dried at 130° C. An attenuated total reflectance spectrum on the elastomer shows strong absorption at 3400 cm.sup. -1 , a frequency attributable to the presence of hydroxyl groups in the elastomer surface. Two pieces of thus treated rubber may be cemented together by the use of a standard room temperature curing epoxy resin formulation such as Hardman Extra Fast Setting Epoxy.
It is readily apparent from the above examples that treatment of the surface of silicone rubber with bromine water substantially improves the bondability of the surface and that the bondability increases with the duration of treatment. Thus, even some treatment, according to this invention, is better than none and the experimental results indicate that the surface energy of the silicone rubber increases gradually with time and tends to level off after approximately five or six hours at room temperature. Obviously, raising the temperature will increase the rate of reaction and lowering the temperature will decrease the rate.
It should be noted that aqueous halogen solutions usable according to this invention need not be formed by the direct dissolving of the halogen in water. Suitable solutions can be obtained by the mixing of relatively inert aqueous solutions of halides and halates such as sodium bromide and sodium bromate to form the aqueous halogen solution in situ. The pH of the halogen solution can be adjusted by addition of a hydroxide such as NaOH. Such higher pH solutions are advantageous because higher halogen concentration can be obtained, corrosive effects on metallic substrates for the silicone rubber are reduced and the light sensitivity of the solutions is reduced. Mixed halogen solutions can also be prepared from, for example, sodium chloride and sodium bromate or sodium bromide and sodium chlorate. Accordingly, it is contemplated that the aqueous halogen solution described herein can be produced by the above approaches as well as by direct solution of halogens.
While the utility of the invention has been discussed with respect to improving the bondability of silicone rubbers, it is readily apparent that increasing the surface energy of a silicone rubber is useful in a wide variety of other applications. Silicone rubbers are used for surgical tubing with which a Heparin treatment is required to prevent clotting and this invention may be useful in preparing the tubing for such treatment. Increasing the surface energy also renders the silicone rubber surface more receptive for dyes and inks permitting printing, for example. Silicone rubbers are also used as semi-permeable membranes where the higher surface energy produced by this invention will increase the wettability and the oxygen permeability.
Although this invention has been described with respect to a specific embodiment thereof, it should not be construed as being limited thereto. Various modifications may be made without departing from the scope of this invention which is limited only by the following claims wherein:
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Treating cured silicone rubber with bromine water etches the normally low energy surface of the silicone rubber to produce a high energy surface to which various curable polymeric systems may be directly bonded.
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BACKGROUND OF THE INVENTION
The present invention relates to ski bindings in general and in particular to a releasable step-in type ski binding comprising a movable clamping member. The movable clamping member has an open and a closed position and is coupled to a force unit comprising a spring member for providing a clamping force for releasably securing a ski boot to a ski rearward of the toe and forward of the rear of the heel of the ski boot.
Step-in bindings greatly facilitate securing a ski boot to a ski. Before the advent of the step-in type ski binding, in order to secure a ski boot to a ski, it was often necessary for a skier to bend over and/or crouch in order to reach the binding parts for engaging the binding parts. With the step-in type ski binding, the binding parts may be set while the skier is in a comfortable and upstanding position. The ski is then placed on the ground and the skier simply places his foot in the binding and pressing downwardly causes the binding mechanism to react and releasably engage mating parts on the ski boot.
In all step-in ski bindings it is important that the various parts of the binding work freely and with minimum forces between the interfacing parts, so as to provide ease of operation and long life and reliability. In order for the binding to be easy to use, it is necessary that the activation of the binding during the step-in procedure does not cause the ski to move unduly from beneath the skier's foot. This is necessary to insure proper mating of the binding parts on the ski and the boot and is particularly important and necessary when the ski is being resecured to a ski boot as after a fall on the side of a hill or under other difficult snow and terrain conditions.
Step-in ski bindings having one or more clamping members releasably securing a ski boot to a ski rearward of the toe and forward of the rear of the heel of the ski boot are disclosed in U.S. Pat. No. 4,063,753 issued to Whitaker et al. and U.S. Pat. No. 3,887,205 issued to Edmund.
In Whitaker et al. there is provided a binding in which a force unit comprising an overcenter mechanism is located at the rear end of the binding. To voluntarily exit the binding, a skier must twist to the rear and bend over to grasp and lift the overcenter mechanism. This can be awkward and difficult under the adverse slope and snow conditions discussed above particularly if the skier is wearing bulky insulated cold-weather clothing.
In Edmund there is provided a binding in which there is located a slot in the forward end of each clamping member. To enter the binding, a boot-mounted plate is inserted in the slot and downward pressure causes the clamping member to move over center. As the downward pressure is applied, however, the ski boot is not in skiing position and there is, therefore, a tendency for the ski to move rearwardly with no convenient means for restricting the movement.
SUMMARY OF THE INVENTION
In view of the foregoing, a principal object of the present invention is a releasable step-in type ski binding for releasably securing a ski boot to a ski rearward of the toe and forward of the rear of the heel of the ski boot.
Another object of the present invention is a releasable step-in type ski binding of the type described above in which the mechanism for operating the binding comprises a ski boot-actuated mechanism for releasing a clamping member for securing the ski boot to a ski.
Another object of the present invention is a releasable step-in type ski binding of the type described above in which means are provided for voluntarily opening the binding with the tip of a ski pole or the like.
Still another object of the present invention is a releasable step-in type ski binding which is simple to use, reliable and requires a minimum of actuating forces.
In accordance with the above objects, there is provided a clamping member for releasably securing a ski boot to a ski rearward of the toe and forward of the rear of the heel of the ski boot. The clamping member comprises an elongated member pivotably mounted in the binding. At the rear end of the elongated member, there is coupled to the elongated member a spring member. Pivotably mounted adjacent to the spring member there is provided a lever member.
In one embodiment, the lever member comprises a first part for engaging the spring and a second part for receiving the heel of a ski boot. The first part is used for compressing the spring so as to open the clamping member at the forward end of the elongated member. The second part is used to close the clamping member.
In operation, as a skier enters the binding, the heel of the ski boot presses the second part of the rear lever member, causing the lever member to pivot away from the spring, permitting the spring to relax. As the spring relaxes, it pushes outwardly on the rear end of the clamping member, allowing the clamping member to engage mating parts on the ski boot.
In another embodiment, there is provided a trigger member which is set when the lever member is used to open the clamping member. Once set, the trigger member holds the clamping member open against the force of the spring until a skier steps down on the top of the trigger member. When the trigger member is depressed, and this occurs with the ski boot in skiing position, the clamping member is released, allowing the clamping member to engage mating parts on the ski boot.
BRIEF DESCRIPTION OF THE DRAWING
The above and other objects, features and advantages of the invention will become apparent from the following detailed description of the accompanying drawing in which:
FIG. 1 is a plan view of one embodiment of a binding according to the present invention.
FIG. 2 is a plan view of the embodiment of FIG. 1 with the upper housing and lever member omitted for clarity and the rear of the binding shown in partial cross section.
FIG. 3 is an elevation view of FIG. 1.
FIG. 4 is a transverse cross-sectional view of the spring assembly of the embodiment of FIG. 1 when the jaw members of the binding are at their closest point.
FIG. 5 is a transverse cross-sectional view of the spring assembly of the embodiment of FIG. 1 when the clamping jaws are clamping a ski boot or boot plate attached to the boot.
FIG. 6 is a transverse cross-sectional view of the transverse spring assembly of the embodiment of FIG. 1 when the jaws of the binding are in their open position.
FIG. 7 is a plan view of an alternative embodiment of a binding according to the present invention.
FIG. 8 is a plan view of the embodiment of FIG. 7 with the upper housing and lever member omitted for clarity and the rear of the binding shown in partial cross section.
FIG. 9 is an elevation view of FIG. 7.
FIG. 10 is a partial cross-sectional view of a step-in member in a clamp-open condition according to the present invention.
FIG. 11 is a plan view of FIG. 10.
FIG. 12 is a partial cross-sectional view of the step-in member of FIG. 10 in a clamp-closed condition.
FIG. 13 is a plan view of FIG. 12.
FIG. 14 is a transverse cross-sectional view of the transverse spring assembly of the embodiment of FIG. 7 when the jaw members of the binding are at their closest point.
FIG. 15 is a transverse cross-sectional view of the spring assembly of the embodiment of FIG. 7 when the clamping jaws are clamping a ski boot or boot plate attached to the boot.
FIG. 16 is a transverse cross-sectional view of the transverse spring assembly of the embodiment of FIG. 7 when the jaws of the binding are in their open position.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is provided in a binding according to the present invention a pair of jaws 1 and 2. The jaws 1 and 2 are shown in three positions: a fully closed position as shown by the broken lines at 3, a clamping position as shown by the solid lines at 4, and a fully opened position as shown by the broken lines at 5. The fully closed position at 3 occurs when no boot or boot plate is between the jaws 1 and 2 and the jaws are free to move unimpeded to their closest position. Position 4 illustrates the position of the jaws when a boot or boot plate is inserted between the jaws. Position 5 illustrates the position of the jaws when the jaws are forced to their openmost position.
Between the jaws, there is shown the upper surface of an upper housing 6 of the binding. At the rear of the housing 6 there is provided a transverse spring assembly designated generally as 10.
In the assembly 10 there is provided a lever member 11. Extending from a forward edge of the lever member 11, there is provided a heel-receiving member 12. Extending from the rear of the lever member 11, there is provided a ski-pole-tip-receiving member 14. In the member 14 there is provided a hole 15 for receiving the tip of a ski pole (not shown).
Forward of the jaws 1 and 2, there is provided a pair of counter-sunk holes 16 and 17 and to the rear of assembly 10, a counter-sunk hole 18. The holes 16, 17 and 18 are provided for mounting the binding to the upper surface of a ski designated as 19.
Referring to FIG. 2, the jaws 1 and 2 extend upwardly from the forward end of a pair of arms 21 and 22, respectively. The arms 21 and 22 are pivotably mounted for rotation in a recess 25 about a pair of posts 23 and 24. The recess 25 and posts 23 and 24 are interior of a pair of side walls 32 and 33, and rearwardly of a forward wall 34 at the forward end of a lower housing 26 which is located beneath the upper housing 6 shown in FIG. 1. Extending inwardly from the forward end of the arms 21 and 22, there is provided a pair of clamp-stop members 30 and 31. Members 30 and 31 determine the distance the jaws 1 and 2 are able to move together. Additionally, the exterior forward ends of the arms 21 and 22 are positioned to pass through openings 35 and 36 provided therefor between the forward edges of the walls 32 and 33 and the wall 34.
Referring to the rear end of the binding, as shown in FIG. 2, there is provided in assembly 10 a transverse spring housing designated generally as 40. In housing 40, there is provided a pair of generally cylindrically shaped spring cavities 41 and 42. Spring cavity 41 is provided for housing a spring 43 and spring cavity 42 is provided for housing a spring 44. As shown in FIG. 1, the cavities 41 and 42 are open at their top, exposing the springs 43 and 44. Extending forwardly from the center of the spring housing 40, between the arms 21 and 22, there is provided a mounting flange 45. At the forward end of the flange 45 there is provided a hole 46. The flange 45 and hole 46 are provided for pivotably mounting the lever member 11 in the assembly 10 as by a pin, bolt, rivet 47, or the like, as shown in FIG. 3.
As seen more clearly in FIGS. 3-6, centrally located between the spring cavities 41 and 42, there is provided, in the mounting flange 45 in the housing 40, a slot 50. The slot 50 is provided for receiving a reduced central bearing section 51a of a threaded stud 51. The stud 51 is provided with two sets of threads 52 and 53. Threads 52 and 53 are oppositely directed and are right and left-hand threads, respectively. Threaded on the stud 51, in the interior of the spring cavities 41 and 42, there is provided a pair of spring compression members 54 and 55. In each of the members 54 and 55, in the lower edge thereof, there is provided a key member-receiving slot 56. The slot 56 is provided for receiving a key member, to be described below with respect to FIGS. 4-6. The slot 56 in members 54 and 55 prevents a rotation of the members 54 and 55 as the stud 51 is rotated. At opposite ends of the stud 51 there is provided a pair of slots 58 and 59. The slots 58 and 59 are provided for receiving a screw driver, coin or the like for turning the stud 51.
At the rear ends of the arms 21 and 22, there is provided upstanding beveled members 60 and 61, respectively. On the exterior of the beveled members 60 and 61 there is provided an exterior compound beveled surface 62 and 63, respectively. The surfaces 62 and 63 slope downwardly outwardly and rearwardly outwardly, thereby defining a compound beveled surface in that the plane of the beveled surface describes an angle with respect to planes both perpendicular and parallel to the axis of the stud 51.
In addition to the beveled surfaces 62 and 63, there is provided in the members 60 and 61, a pair of relatively flat surfaces 62a and 63a, respectively. The beveled surfaces 62 and 63 and the flat surfaces 62a and 63a are provided for receiving a pair of corresponding surfaces 72 and 73 in a pair of wall members 70 and 71 in the lever member 11 for holding the lever member in its clamp-open position against the force of the springs 43 and 44 until pressure is brought to bear on the member 12.
In the center of each of the upstanding members 60 and 61, there is provided a hole 64. The hole 64 in each of the upstanding members 60 and 61 is provided for receiving one of the ends of the stud 51 or for providing access to the slots 58 and 59 provided in the ends thereof.
Referring to FIGS. 3-6, extending from the lower edge thereof, upwardly toward the center of the lever member 11, there is provided in the side walls 70 and 71 a slot 74. The slot 74 is provided for passing freely over the ends of the stud 51 and for providing access to the slots 58 and 59 in the ends of the stud 51.
As seen in FIG. 3, when the lever member 11 is pivoted counter-clockwise to the fullest extent possible, the upper surface 13 of the heel-receiving member 12 lies below the plane of the upper surface of the upper housing 6. This is possible because the housing 6 is provided with a recessed or lowered upper surface 6a in the vicinity of the heel-receiving member 12.
Referring to FIGS. 4-6, as previously described, the beveled surfaces 62 and 63 and the flat surfaces 62a and 63a of the upstanding members 60 and 61 at the rear ends of the arms 21 and 22, respectively, are provided for slidably receiving corresponding surfaces 72 and 73 on the interior of the side wall members 70 and 71, respectively. Below the stud 51 and at the lower end of the spring compression members 54 and 55, there is provided key members 74 and 75, respectively. The key members 74 and 75 are provided for slidably engaging the key slot 56 provided therefor in the lower edge of each of the members 54 and 55 for preventing rotation of the members 54 and 55 as the stud 51 is rotated. Beneath the key members 74 and 75, there is provided a clearance space 76 and 77 for receiving interior portions of the arms 21 and 22, respectively.
In practice, when the jaw members 1 and 2 are at their closest position, the rear ends of the arms 21 and 22, and in particular the upstanding members 60 and 61, are farthest apart, as shown in FIG. 4. With the tip of a ski pole placed in the hole 15 in the member 14 at the rear of the lever member 11, the lever member 11 may be pivoted clockwise about the pin 47. As the lever member 11 is pivoted clockwise about the pin 47, the interior surfaces 72 and 73 of the side wall members 70 and 71 slidably engage the beveled surfaces 62 and 63 of the upstanding members 60 and 61 at the rear ends of the arms 21 and 22, respectively. As the surfaces 72 and 73 engage the surfaces 62 and 63, the arms 21 and 22 are caused to pivot about the posts 23 and 24, the springs 43 and 44 are compressed between the interior of the upstanding member 60 and the spring compression member 54 and the interior of the upstanding member 61 and the spring compression member 55, respectively. At the same time the jaws 1 and 2 are caused to pivot to their outermost position 5, as shown in FIGS. 1 and 2. With the jaws 1 and 2 in their outermost position 5, as shown in FIGS. 1 and 2, the springs 43 and 44 are compressed, as shown in FIG. 6.
As a skier steps into the binding, the heel of the ski boot engages the upper surface 13 of the heel-receiving member 12. As the heel of the boot engages the member 12, and a force is brought to bear thereon, the lever member 11 is caused to pivot counter-clockwise about the pin 47. As the lever member 11 pivots counter-clockwise, the side walls 70 and 71 of the lever member 11 are caused to separate from the upstanding members 60 and 61. As this occurs, the springs 43 and 44 are allowed to extend to the fullest extent possible, limited only by the width of the boot receiver or boot plate which the jaws 1 and 2 are engaging.
To adjust the force with which the jaws 1 and 2 engage a boot receiver or boot plate attached thereto, a screw driver, coin or the like is inserted in the slot 58 or 59 to turn the threaded stud 51. As the threaded stud 51 is rotated, the spring compression members 54 and 55, due to the opposite pitch of the threads 52 and 53, move in opposite directions. Accordingly, when rotated in one direction, the stud 51 will cause the spring compression members 54 and 55 to move outwardly, further compressing the springs 43 and 44, increasing the clamping force applied to the jaws 1 and 2, respectively. Conversely, when the stud 51 is rotated in the opposite direction, the spring compression members 54 and 55 are caused to move inwardly relative to each other, allowing the springs 43 and 44 to extend and thereby reduce the clamping force applied to the jaws 1 and 2, respectively.
The distance that the springs 43 and 44 are required to compress between a fully open and fully closed position of the jaws 1 and 2 is dependent on the distance between the springs 43 and 44 and the pivot posts 23 and 24 and the distance between the jaws 1 and 2 and the pivot posts 23 and 24, respectively. The clamping forces applied to the jaws 1 and 2 is also dependent on these distances. Accordingly, for any given spring, the clamping force can be adjusted by adjusting the distances mentioned. Additionally, the clamping force can be adjusted by changing the strength of the springs 43 and 44.
Referring to FIGS. 7-16, there is provided in an alternative embodiment of the present invention a step-in binding designated generally as 100. In the binding 100 there is provided many of the features described above with respect to the embodiment of FIGS. 1-6. These features bear the same identifying numbers used in FIGS. 1-6. The primed numbers below refer to features of FIGS. 1-6 which are modified in FIGS. 7-16 as described below but which otherwise function as described above with respect to FIGS. 1-6.
At the rear end of the binding 100 there is provided a lever member 11' from which is eliminated the heel-receiving member 12 of the member 11.
For momentarily engaging the springs 43 and 44, the lever member 11' is provided with a pair of downwardly depending side walls 70' and 71'. In their interior, the side walls 70' and 71' are provided with a pair of beveled surfaces 72' and 73'. The surfaces 72' and 73' are provided for slidably engaging a corresponding pair of compound beveled surfaces 62' and 63' located on the exterior surface of a pair of upstanding members 60' and 61' on the rear end of a pair of elongated clamping members 21' and 22'.
The walls 70' and 71' and surfaces 62', 63', 72' and 73' are identical to the walls 70, 71 and surfaces 62, 63, 72 and 73 of FIGS. 1-6 except that the flat surfaces 62a and 63a are omitted for facilitating the removal of the lever member 11' from the springs 43 and 44 as explained below. The clamping members 21' and 22' are identical to the members 21 and 22 of FIGS. 1-6 except for the surfaces 62' and 63' and a pair of slots 101 and 102 at the forward end thereof.
The slots 101 and 102 located at the forward ends of the members 21' and 22' are located generally between the jaws 1 and 2. Each of the holes 101 and 102 generally comprises a pair of intersecting holes of different diameters with the smaller of the holes located outwardly of the larger hole.
Located in the holes 101 and 102 there is provided a pair of step-in members 103 and 104, respectively. As seen in FIG. 7, and as will be described in more detail with respect to FIGS. 10-13, the step-in members 103 and 104 project upwardly through holes provided therefor in an upper housing 6' of the binding 100 between the jaws 1 and 2. The housing 6' is identical to the housing 6 of FIG. 1-6 except for the holes for the members 103 and 104.
Referring to FIGS. 10-13, the step-in members 103 and 104 are identical. Accordingly, only step-in member 103 and the hole 101 will be described.
As described above, each of the holes 101 and 102 comprises a pair of intersecting holes of different diameters. For purposes of describing the holes, the smaller of the holes is designated as 105 and the larger of the holes is designated as 106.
The step-in member 103 is provided with a generally cylindrical, hollow upper portion 107 and a cylindrical lower portion 108 having a larger diameter. In the interior of the step-in member 103 there is provided a spring 110.
Located below the step-in member 103 there is provided in a lower housing 26' a well or hole 109. The housing 26' is identical to the housing 26 of FIGS. 1-6 except for the well 109.
To accommodate the step-in member 103, the smaller hole 105 of the two holes 101 in the clamping arm 21' has a diameter slightly larger than the diameter of the upper portion 107 of the step-in member 103. The larger diameter hole 106 of the two holes 101 in the clamping member 21' is slightly larger than the diameter of the lower portion 108 of the step-in member 103. The diameter of the well 109 in the lower housing 26' is slightly larger than the lower portion 108 of the step-in member 103 for slidably receiving the lower portion 108, as will be further described.
In operation, as the lever member 11' is pivoted downwardly by a ski pole or the like inserted in the hole 15 provided therefor, the beveled surfaces 72' and 73' of the side walls 70' and 71' of the lever member 11' engage the corresponding beveled surfaces 62' and 63' of the upstanding members 60' and 61' at the rear ends of the clamping members 21' and 22'. As the upstanding members 60' and 61' of the clamping members 21' and 22' are squeezed together against the force of the spring members 43 and 44, the forward ends of the clamping members 21' and 22' are pivoted outwardly. As the forward ends of the clamping members 21' and 22' are pivoted outwardly, the spring members 110 in the step-in members 103 and 104 push the step-in members 103 and 104 upwardly through the holes provided therefor in the upper housing 6'. At the same time the lower portion 108 of the members 103 and 104 becomes seated in the larger diameter hole 106 of the two holes 101, as shown in FIG. 11. With the lower portion 108 of the step-in members 103 and 104 seated in the larger diameter hole 106, the step-in members 103 and 104 are set. With the step-in members 103 and 104 set, the ski pole or the like inserted in the hole 15 provided therefor in the lever member 11' can be removed therefrom and a leaf spring 115 or the like bearing against a rear surface of the lever member 11' will pivot the lever member 11' in a counter-clockwise direction away from the spring members 43 and 44, as shown in FIG. 9.
With the step-in members 103 and 104 set, and the lever member 11' free of the spring members 43 and 44, a skier may insert a ski boot into the binding.
As the skier inserts a ski boot into the binding with the boot plate provided thereon located in skiing position between the jaw members 1 and 2, contact will be made with the upper surface of the step-in members 103 and 104. As pressure is brought to bear thereon, the step-in members 103 and 104 are pushed downwardly into the hole 109 in the lower housing 26, as shown in FIG. 12. As the step-in member 103 enters the hole 109, the lower portion 108 thereof is removed from the larger diameter hole 106 of the pair of holes 101 in the clamping member 21'. As the lower portion 108 is removed from the hole 106, the spring 43, pushing against the rear of the clamping arm 21', pivots the forward end of the clamping arm 21' inwardly as shown by the arrow in FIG. 13, until the upper portion 107 of the step-in member 103 is located in the smaller hole 105 of the two holes 101 in the clamping member 21'.
While the upper portion 107 of the step-in member 103 is shown in FIG. 13 to be fully seated in the smaller diameter hole 105 of the pair of holes 101, it is understood that, if the width of the boot plate or the width of a ski boot limits the distance the jaws 1 and 2 are permitted to close, the upper portion 107 of the step-in members 103 and 104 would not be fully seated in the smaller diameter hole 105 of the pair of holes 101. On the other hand, if the width of the boot plate of the boot is smaller requiring that the jaws 1 and 2 move closer together than shown, then the smaller diameter hole 105 of the pair of holes 101 may be enlarged or elongated to permit the jaws 1 and 2 to move closer together.
While two embodiments of the present invention are described in detail, it is contemplated that various modifications and changes may be made to the embodiments described without departing from the spirit and scope of the present invention. Accordingly, it is intended that the scope of the invention not be limited to the embodiments described but rather be determined by reference to the claims hereinafter provided and their equivalents.
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A releasable step-in ski binding has movable clamping members (1,2) at the forward ends of a pair of elongated arms (21,22,21',22'). The rear ends of the arms (21,22,21',22') are coupled to a pair of transverse spring members (43,44) forming a transverse spring assembly (10). A lever member (11,11') is pivotably mounted on the binding and has a first position for compressing the rear ends of the arms (21,22,21'22') against the springs (43,44) for opening the clamping members (1) and (2). Extending from the lever member (11,11') there is provided a member (14) for receiving a ski pole tip to move the lever member (11,11') to its first position for opening the clamping members (1,2). In one embodiment a ski boot receiving member (12) for moving the lever member (11) to a second position is provided for closing the clamping members (1,2). In another embodiment a trigger member (103) between the clamping members (1,2) is provided for closing the clamping members (1,2).
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit to provisional patent application No. 60/998,857, filed 12 Oct. 2007, which is hereby incorporated be reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for dispensing a fluid; and more particularly relates to a dispensing system having a multiple tube inlet.
2. Brief Description of Related Art
There are many dispensing systems on the market and known in the art, some of which include the following:
U.S. Pat. No. 5,272,960 discloses a dispensing machine having an electromechanical delivery of fluid from a reservoir to an infusion-type beverage arranged in a sachet with valves and solenoids based on a technique that increases the pressure within an initially sealed package so as to rupture and release beverage material therein by applying heat to the seal the package to minimize ruptures.
U.S. Pat. No. 5,858,437 discloses a method of brewing reduced temperature coffee also having an electromechanical delivery of fluid from two reservoir at different temperatures (e.g. 100° and 200°) with valves and controllers to a brew funnel containing coffee based on a technique that dispenses a predetermined quantity of temperature reduction water from one of the reservoirs.
U.S. Pat. No. 4,892,031 discloses a modularized custom beverage brewer using a technique based on the control of a cantilevered portion and control means for delivering fluid to a spray head that provides the fluid to beverage grounds for dripping a brewed beverage.
U.S. Pat. No. 4,793,246 discloses an electrically operated hot beverage maker using a technique based on a flexible, expandable water container that fills with water and expands laterally to accommodate more water than when the container is in the relaxed position.
Moreover, there are other known dispensing systems; however, none of these known dispensing systems have multiple inlet sources.
Some problems with the known dispensing systems include one or more of the following:
Allow for only one inlet source, requiring manual change over Requires excessive manual change overs, which is undesirable during peak business hours Collapses the bottle due to drawing vacuum and not shutting off. Contamination to the fluid system. Some units require flooded inlet.
In effect, none of the aforementioned systems or techniques pertain to Venturi-based fluid dispensing, especially from dispensers having multi-inlet tubing.
SUMMARY OF THE INVENTION
The present invention provides a new and unique method and apparatus for dispensing fluid from multiple reservoirs.
The apparatus features a system having a dispenser configured to provide fluid from multiple reservoirs to an appliance or other suitable device; and a multiple tubing arrangement configured to couple the dispenser and the multiple reservoirs of fluid, the multiple tubing arrangement being responsive to a vacuum provided from the dispenser, for drawing the fluid from the multiple reservoirs so as to deplete the multiple reservoirs at relatively equal amounts based on the Venturi effect.
The multiple tubing arrangement comprises some combination of a primary inlet tube configured for arranging in a primary reservoir, an auxiliary inlet tube configured for arranging in an auxiliary reservoir, a feed connector tube configured for arranging between the primary inlet tube and auxiliary inlet tube, an inlet suction tube configured for arranging between the dispenser and the primary inlet tube, or a discharge tube configured for arranging between the dispenser and the appliance.
The primary inlet tube may include a Venturi device having inlet and outlet ports for respectively receiving an auxiliary feed and providing a primary feed, as well as tubing for inserting into the primary reservoir, and may be configured to couple to the auxiliary inlet tube so as to provide a proportional vacuum and siphoning effect.
The auxiliary inlet tube may also include a device having an outlet port for providing the auxiliary feed, as well as tubing for inserting into the auxiliary reservoir. Embodiments are envisioned using multiple auxiliary reservoirs that are daisy chained together, where one or more of the auxiliary inlet tubes may also include an associate Venturi device having inlet and outlet ports for respectively receiving an auxiliary feed from another auxiliary reservoir and providing an associate primary feed, as well as associated tubing for inserting into its associated auxiliary reservoir. In such embodiments, an end auxiliary inlet tube would typically include an associated device having an associated outlet port for providing an associated auxiliary feed to a next auxiliary inlet tube, as well as associated tubing for inserting into its associated auxiliary reservoir.
The dispenser may include a diaphragm positive displacement pump that draws fluid from the primary reservoir via the primary inlet tubing.
In operation, the multiple tubing arrangement is configured to siphon and deplete the fluid from the primary reservoir and the auxiliary reservoir based on the Venturi effect. For example, the primary inlet tube may include a Venturi device arranged therein for creating a suction. The Venturi device may include a short tube with a tapering constriction in the middle that causes an increase in velocity of flow of the fluid and a corresponding decrease in fluid pressure.
The system also features a discharge tube configured to couple the dispenser and the appliance.
The multiple reservoirs may be open to atmospheric pressure, and does not require container vacuum to create the proportional vacuum and siphoning effect.
The number of auxiliary inlet tubes and reservoirs depends on the amount of vacuum generated by the dispenser.
The present invention may also take the form of a method featuring coupling a multiple tubing arrangement between a dispenser and multiple reservoirs of fluid; and activating the dispenser for generating a vacuum in the multiple tube arrangement so as to draw the fluid from the multiple reservoirs, deplete the multiple reservoirs at relatively equal amounts based on the Venturi effect, and provide the fluid from the dispenser for provisioning to an appliance.
The present invention may also take the form of a kit featuring a dispenser for providing fluid from multiple reservoirs to an appliance or other suitable device; and a multiple tubing arrangement configured for coupling between the dispenser and the multiple reservoirs of fluid, the multiple tubing arrangement also being configured for responding to a vacuum provided from the dispenser, for drawing the fluid from the multiple reservoirs so as to deplete the multiple reservoirs at relatively equal amounts based on the Venturi effect. In this embodiment, the multiple tubing arrangement may include some combination of a primary inlet tube configured for arranging in a primary reservoir, an auxiliary inlet tube configured for arranging in an auxiliary reservoir, a feed connector tube configured for arranging between the primary inlet tube and auxiliary inlet tube, an inlet suction tube configured for arranging between the dispenser and the primary inlet tube, or a discharge tube configured for arranging between the dispenser and the appliance.
Some advantages of the present invention include:
Allows for multiple inlet sources; Providing multiple inlet sources limits time between change over; Provides a continuous vacuum loop between the tubes; Eliminates the cross contamination due to the continuous loop; and Equal size tubes allows for equal distribution of water to level the reservoirs.
BRIEF DESCRIPTION OF THE DRAWING
The drawing, which is not necessarily drawn to scale, includes the following Figures:
FIG. 1 is a diagram of a system according to some embodiments of the present invention.
FIG. 2 is a diagram of the basic parts of the invention that form part of the system in FIG. 1 .
FIG. 3 shows a diagram of the dispensing system shown in FIG. 1 .
FIG. 4 includes FIGS. 4A and 4B ; FIG. 4A shows a diagram illustrating the basic principle of operation of a Venturi Device; and FIG. 4B shows, by way of example, a Venturi device for using as part of a multiple inlet tube dispensing system according to some embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show a new and unique system generally indicated as 10 according to the present invention that includes a primary inlet tube generally indicated as (A), a dispenser or dispensing system generally indicated as (B), a discharge tube generally indicated as (C), an auxiliary inlet tube generally indicated as (D), a reservoir generally indicated as (E), an appliance generally indicated as (F), a feed connector tube generally indicated as (G) and an auxiliary reservoir generally indicated as (H).
By way of example, the system 10 operates as follows:
As the dispenser or dispensing system (B) is turned on or activated, it will start drawing vacuum through the primary inlet tube (A), and also draw a proportional amount of vacuum from the auxiliary inlet tube(s) (D), which are connected through the feed connector tube (G), as long as the discharge tube (C) is unrestricted.
The discharge tube (C) is coupled between an output for the dispensing system (B) via outlet/discharge tube/port B- 3 ( FIG. 3 ) and an input to an appliance (F), which is shown by way of example as a coffee machine with one or more coffee pots f 1 , f 2 . The scope of the invention is not intended to be limited to the type or kind of appliance or equipment that receives the fluid being dispensed from the dispensing system (B). The dispenser (B) also has inlet/suction tubing B- 2 (see also FIG. 3 ) coupled to an output port (O) (see FIG. 4B ) of the primary inlet tubing (A) for receiving a primary feed of fluid, as well as a plug (P) for coupling to a power source.
By way of example, the present invention is shown and described using one auxiliary inlet tube (D), although the scope of the invention is not intended to be limited to any particular number of auxiliary inlet tubes (D). For example, embodiments are envisioned in which multiple auxiliary tubes and associated auxiliary reservoirs are daisy chained together and coupled to the primary inlet tube (A). However, as a person skilled in the art would appreciate, the number of auxiliary inlet tubes (D) may typically limited to the amount of vacuum generated by the dispensing system (B).
As shown in FIGS. 1 and 2 , the auxiliary inlet tube (D) is connected to the primary inlet tube (A) via the feed connector tube (G) such that it provides a proportional vacuum and siphoning effect. The siphoning effect is the vacuum created by the primary tube (A) drawing fluid up the auxiliary tube (D). Soon after the primary inlet tube (A) has evacuated air, the Venturi device (see also FIGS. 4A and 4B ) starts drawing fluid from the auxiliary reservoir (H) through the feed connector tube (G). As the fluid level in the main reservoir (E) drops, the siphon draws fluid from the auxiliary reservoir (H) through the Venturi effect, which is illustrated in more detail in FIGS. 4A and 4B .
By way of example, in the system 10 shown and described herein, both the primary and auxiliary reservoirs (E) and (H) are open to atmospheric pressure, and there is no container vacuum required to create the siphoning effect. However, it is important to note that the scope of the invention is not intended to be limited to only open atmospheric type pressure systems, because embodiments are envisioned within the spirit of the invention so as to include other types or kinds of atmospheric type pressure systems either now known or later developed in the future.
As a pump (B- 1 , see FIG. 3 ) in the dispensing system (B) initially starts, it evacuates the air trapped in the primary inlet tube (A) first, and draws on the fluid in the primary reservoir (E). By way of example, the pump (B- 1 ) may take the form of a diaphragm positive displacement pump for drawing fluid from the primary reservoir (E), although embodiments are envisioned using other types or kind of pumps either now known or later developed in the future.
As the fluid is removed from the primary inlet tube (A), it pulls or draws the air from the feed connector tube (G) under the Venturi effect, consistent with that illustrated in FIGS. 4A and 4B . By way of example, the primary inlet tube (A) may include a Venturi device (V) like that shown in FIG. 4B having an inlet port (I) and the outlet port (O) for respectively receiving an auxiliary feed and providing the primary feed, as well as tubing (T) for inserting into the primary reservoir (E).
As the fluid in the primary reservoir (E) depletes, the vacuum created in the auxiliary inlet tube (D) provides siphon from the auxiliary reservoir (H) via the feed connector tube (G). By way of example, the auxiliary inlet tube (D) may include a corresponding device d 1 having an outlet port for providing the auxiliary feed to the primary inlet tube (A) via the feed connector tube (G), as well as tubing d 2 for inserting into the auxiliary reservoir (H). In an embodiment using multiple auxiliary reservoirs that are daisy chained together, one or more of the auxiliary inlet tubes may include an associate Venturi device like Venturi device (V) in FIG. 4B having associated inlet and outlet ports for respectively receiving an associated auxiliary feed from another auxiliary reservoir and providing an associate primary feed, as well as associated tubing for inserting into its associated auxiliary reservoir. These one or more auxiliary inlet tubes may be referred to as intermediate auxiliary inlet tubes arranged between the primary inlet tube and an associated end auxiliary tube, like the auxiliary inlet tube (D). In such embodiments, the end auxiliary inlet tube would typically take the form of like the auxiliary inlet tube (D) consistent with that described herein.
Because of the siphon, the primary reservoir (E) and auxiliary reservoir (H) will deplete at relatively equal amounts depending on the diameters of d 1 (e.g. 0.225″ as shown in FIG. 4B ) of the inlet port (I) or the outlet port (O), or the diameter d 2 (e.g. 0.685″ as shown in FIG. 4B ) of the tubing (T). The diameters are shown by way of example, and the scope of the invention is not intended to be limited to any particular diameter or dimensional relationship between such diameters d 1 and/or d 2 . For example, embodiments are envisioned using other diameters for d 1 or d 2 having the same or possibly a different dimensional relationship between these diameters d 1 and/or d 2 .
The Venturi Effect
FIG. 4A shows a diagram illustrating the basic principle of operation of a Venturi device. As a person skilled in the art would appreciate, the Venturi effect is the fluid pressure that results when an incompressible fluid flows through a constricted section of pipe. The Venturi effect may be derived from a combination of Bernoulli's principle and the equation of continuity. The fluid velocity must increase through the constriction to satisfy the equation of continuity, while its pressure must decrease due to conservation of energy: the gain in kinetic energy is supplied by a drop in pressure or a pressure gradient force. The limiting case of the Venturi effect is choked flow, in which a constriction in a pipe or channel limits the total flow rate through the channel, because the pressure cannot drop below zero in the constriction. Choked flow is used to control the delivery rate of water and other fluids through spigots and other valves. Referring to the diagram in FIG. 4 a , using Bernoulli's equation in the special case of incompressible fluids (such as the approximation of a water jet), the theoretical pressure drop (P 1 −P 2 ) at the constriction would be given by
ρ
2
(
υ
2
2
-
υ
1
2
)
.
FIG. 4B shows, by way of example, a Venturi device for using as part of a primary inlet tube (A) that forms part of a multiple inlet tube dispensing system according to some embodiments of the present invention, having two ports, one output port (O) for providing a primary feed, e.g. to the dispensing system (B), and another input port (I) for receiving an auxiliary feed from the auxiliary inlet tubing (D), consistent with that described above.
Possible Applications
Possible applications of the present invention may include at least the following:
Beverage systems, fluid dispensing systems, water supply systems; any system in which there is a supply system, reservoir and dispensing system, In commercial applications where there is a supply of either water or any other fluid to an appliance, whereas fluid level or presence is detected by any sensing means or mechanism, car wash, ware wash, cisterns, septic tanks, and any other applicable application that requires level sensing, or where relatively low ratio mixing is required.
The Scope of the Invention
It should be understood that, unless stated otherwise herein, any of the features, characteristics, alternatives or modifications described regarding a particular embodiment herein may also be applied, used, or incorporated with any other embodiment described herein. Also, the drawings herein are not drawn to scale.
Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein and thereto without departing from the spirit and scope of the present invention.
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The present invention provides a system featuring a dispenser for providing fluid from multiple reservoirs to an appliance or other suitable device; and a multiple tubing arrangement coupled between the dispenser and the multiple reservoirs of fluid, the multiple tubing arrangement being responsive to a vacuum provided from the dispenser, for drawing the fluid from the multiple reservoirs so as to deplete the multiple reservoirs at relatively equal amounts based on the Venturi effect. The multiple tubing arrangement comprises a primary inlet tube for arranging in a primary reservoir, an auxiliary inlet tube for arranging in an auxiliary reservoir, and a feed connector tube arranged between the primary inlet tube and auxiliary inlet tube. The primary inlet tube is coupled to the auxiliary inlet tube so as to provide a proportional vacuum and siphoning effect. The multiple tubing arrangement siphons and depletes the fluid from the primary reservoir and the auxiliary reservoir based on the Venturi effect.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a seal or weatherstrip for a door and more particularly to a door bottom seal which is automatically actuated to seal the gap between a door bottom and its sill as the door is closed and automatically retracted when the door is opened.
2. Description of the Prior Art
Typically, door bottom seals or weatherstrips comprise a flexible sealing element held within a mounting means attached to the bottom of a door. The purpose of the weatherstrip is to block drafts, light, noise, and foreign objects from passing through the space normally provided between the bottom of the door and the door sill. However, these sealing means are subject to wear and deterioration due to the rubbing of the sealing element against the door sill and floor as the door is opened and closed. This is especially true if the sealing element is forced against the door sill to obtain a more effective seal. Moreover, if the floor near the door sill is covered with carpeting, the sealing element causes undue wear on the carpet and requires unnecessary effort to operate the door. Additionally in actual installation the floor and door bottom are not necessarily parallel and therefore a completely effective seal is not possible with a fixed element.
Different methods of overcoming the rubbing and wearing problems of these sealing means have been attempted, including the resilient supporting of the sealing element in the mounting element, and automatic door seals such as shown in U.S. Pat. No. 3,131,441 to G.W. Cornell for WEATHER STRIP, but they do not work as effectively as the present invention. The automatic door bottom of U.S. Pat. No. 3,703,788 overcame these problems and the following is an improvement over the device shown therein.
SUMMARY OF THE INVENTION
Briefly, the present invention is an automatic door bottom for sealing the gap between the bottom of a door and its adjacent sill when the door is closed. The door bottom comprises an inverted U-shaped channel which is internally divided into upper and lower sections and is mounted along the bottom of a door. A flexible sealing element is carried within the channel on a drop bar assembly. Means are provided for reciprocating the sealing element partially out of and back into the channel upon closing and opening the door respectively. The means for reciprocating the sealing element includes a pushrod actuated by bearing against the jamb of the door as the door is closed and spring means for retracting the sealing element when the door is opened. One or two pairs of interactive magnets are employed on the automatic door bottom to permit one end of the flexible sealing element to contact the door sill before the other. This is accomplished by placing one magnet of each pair in the upper internal section of the channel and the second magnet of each pair on the drop bar assembly. One pair of magnets repels each other while the second pair, if employed, attract each other. This has the effect of forcing the end of the drop bar assembly with the repelling pair of magnets out of the channel before the other end.
It is therefore an important object of the present invention to provide an improved automatic door bottom for sealing the gap between the bottom of the door and the sill.
Another object of the present invention is to provide a weatherstrip which can be mounted either on the surface of a door or within the bottom of the door and the sill.
A still further object of the present invention is to provide a door bottom which can be easily manufactured and assembled and easily adjusted during installation to fit a range of different widths of doors and sizes of gaps between the door and its sill.
Yet another object of the present invention is to provide an automatic door bottom which seals one end before the other to minimize closure problems and maximize sealing ability.
BRIEF DESCRIPTION OF THE DRAWINGS
The specific nature of the invention, as well as other objects, aspects, uses, and advantages thereof, will clearly appear accompanying drawings, in which:
FIG. 1 is a side elevational showing the preferred embodiment of the present invention mounted on an open door;
FIG. 2 is a partial top cross sectional view taken along line 2--2 of FIG. 1 showing the extending pushrod of the present invention in two positions, before and after contact with the door frame;
FIG. 3 is a front cross sectional view of the present invention;
FIG. 4 a front perspective view of the present invention;
FIG. 5 is a side cross sectional view of the present invention taken line 5--5 of FIG. 3;
FIG. 6 is a side cross sectional view of the present invention taken line 6--6 of FIG. 3; and
FIG. 7 is a side cross sectional view of the present invention taken along line 7--7 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and initially to FIG. 1, the automatic door bottom 11 of the present invention includes an extruded metallic channel 13, preferably made of aluminum or aluminum alloy. As shown in FIGS. 5-7, the channel 13 is an inverted "U" shape for mounting along the bottom of a door. (See also FIGS. 1-2 and 4-5 of U.S. Pat. No. 3,703,788, the disclosure of which is incorporated herein by reference.) The upper surface 21 of the channel has a plurality of holes 17 formed therein to permit the channel to be screwed onto the bottom edge of a door. The channel 13 may take any other convenient shape dictated by the particular mounting arrangement such as shown, for example, in FIG. 6 of U.S. Pat. No. 3,703,788.
The channel is shown in FIGS. 5-7 as having an elongated, rectangular inverted U-shaped portion comprising a flat horizontal top 21 and two vertical legs 23 and 25. The interior surface of the leg portions 23 and 25 are provided with integral longitudinal rib members 27 and 29 extending toward the opposite leg. These rib members 27 and 29 are approximately one-third of the way from the top 21 and divide the interior of the channel 13 into upper and lower internal sections 31 and 33 connected by an opening between the ribs 27 and 29. The upper section 31 is disposed along the closed portion of the U-shaped channel, adjacent to the flat horizontal top 21, and the lower section 33 is disposed along the open portion of the channel 13. The ribs 27 and 29, as shown, are formed during the extruding of the channel 13, but may be made from separate elements and fixed to the legs 23 and 25 in any suitable manner.
A pushrod and spring assembly 35, shown in detail in FIGS. 3 and 4 is slidably insertable into the upper section 31 of the channel 13.
The pushrod and spring assembly 35 includes a fixed block 37 and a slide block 39 which are formed to be disposed within the upper internal section 31 of the channel 13. In the preferred embodiment, they are rectangular blocks the first of which, 37, has a drilled and tapped hole formed therein whereby it can be removably secured in the channel 13 in a predetermined position (see FIG. 4), e.g. by a screw 73. The second block 39 is freely mounted within the upper internal section and is slidable with respect to the first block 37.
The two blocks 37 and 39 are connected by a curved leaf spring 41, preferably of spring steel, which is fixedly attached to the two slide blocks 37 and 39 in any convenient manner. The leaf spring 41 is concave or dish-shaped and has its central portion 43 extending into the lower section 33 of the channel 13. The spring 41 has a dimpled or depressed portion 45 formed on the concave side thereof, approximately midway between the blocks 37 and 39 for locating a pivot pin 63.
A pushrod 47 is connected to the slidable second block 39 and projects away from the spring member 41 and out of the end of the channel 13. The rod 47 has screw threads formed on the outer end thereof onto which an adjustable end cap 49 may be threaded. The end cap 49 has a multisided cross-section, preferably hexagonal in shape, with a slot 51 formed on its outer end to enable it to be adjusted on the metallic rod 47 by a screw driver or the like. The end cap 49 makes the pushrod 47 adjustable in length and permits it to be locked against change of adjustment when the door bottom 11 is assembled in operating condition. This is effected by the end cap 49 extending into the channel 13 and being of such a size as to be captured within the channel walls and prevented from rotating. In a preferred embodiment, one flat side of the end cap 49 rests against the top of the channel 13 (see also FIG. 6 of U.S. Pat. No. 3,703,788).
To change adjustment of the length of the pushrod 47, the block 37 is released from its connection with the channel 13, and the pushrod and spring assembly 35 is slid out of the channel 13 until the end cap 49 is free thereof and can be turned to effect a new length of the pushrod. The assembly is then reinserted and the first slide block 37 is again secured in position. The end cap 49 is then prevented from turning and changing adjustment.
A drop bar assembly 57 is freely mounted within the lower section 33 of the channel 13 and comprises an extruded H-shaped member 59 holding a flexible sealing element 61. The drop bar 57 is connected to the pushrod and spring assembly 35 by a pivot pin 63 or the like in an upper compartment formed in the drop bar 57. Drop bar 57 has slots 65 formed on each outside edge portion which hold T-shaped sealing strips 67. (See FIGS. 3C and 3D of U.S. Pat. No. 3,703,788). The bottom compartment of the drop bar includes a pair of horizontally inwardly projecting flanges 69 which co-act with slots formed in a reduced size upper portion 71 of the flexible sealing element 61 to hold the sealing element 61 in the drop bar (See FIGS. 5-7). The sealing element 61 is made, for example, from neoprene and which may include a hollow or sponge filled lower portion.
To assemble the door bottom 11, the depressed (central) portion of the leaf spring 41 is placed in the upper compartment of the drop bar 57 and is held therein by the pivot pin 63 or any equivalent fastener to form a single or unitary unit. The blocks 37 and 39 of the pushrod and spring assembly 35 are then slid into the upper section 31 of the U-shaped channel 13 while, at the same time the drop bar assembly 57 attached thereto is slid into the lower section 33. The tapped hole in the block 37 is aligned with a hole formed in one of the legs of the channel 13 and a retaining screw 73 is inserted holding the block 39 and thereby the single unit comprising the pushrod 47, spring 41, and drop bar assemblies 57 in position. In the assembled condition of FIGS. 3-7, the drop bar assembly 57 rests entirely within the lower section 33 of the U-shaped channel 13.
The assembled door bottom 11 may be fixed on a door with the bottom of the channel 13 flush with the bottom of the door, as shown in FIG. 1. Because of the adjustability of the pushrod and spring assembly 35, the channel 13 and drop bar assembly 57 may be reduced in length by a hacksaw as much as six inches to fit a wide range of door widths. Furthermore, the pushrod and spring assembly 35 may be easily inserted from either side of the channel 13 to allow for left hand or right hand installation. This enables one standard size door bottom 11 to be easily cut to fit different bottom gaps, and opening from different directions, right at the job site. In addition, this permits the door bottom 11 to be mass produced from mainly extruded pieces of material, all the channels and the sealing elements, with the only exception being the pushrod and spring assembly 35 which is of extremely simple manufacture, for a wide variety of sizes of doors, thereby effecting great savings in manufacturing costs.
When the weatherstrip is mounted on the door of FIG. 1, a striker plate (not shown) is attached to the door jamb in such a position that upon closing the door, the end cap 49 contacts the plate (See FIG. 2 depicting the action of the end cap 49 upon contact with the door jamb). This causes the end cap 49 to be driven into the channel 13, driving the slide block 39 in the first internal section 31 to the right, as viewed in FIG. 3. The movement of the second slide block 39 causes the leaf spring 41 to be further flexed or dished due to the retaining screw 73 holding the block 37. As the leaf spring 41 is further dished, it is driven further into the second internal section 33 and acts against the drop bar thereby forcing the entire drop bar assembly 57 downwardly, against the frictional force of the sealing strips 67, and partially out of the lower section of the channel until it contacts the door sill. The amount of movement or reciprocation of the drop bar assembly 57, and therefore the pressure of the sealing element 61 against a door sill is, of course, dependent on the space between the bottom of the door and the amount of travel of the sealing element 61. This travel is adjustable up to a maximum of approximately one inch by adjusting the end cap 49 on the pushrod 47.
With the door bottom 4 of the present invention installed on the door as illustrated in FIG. 1, the sealing element 61 will be automatically retracted, as the door is opened, entirely into the channel 13 by the action of the leaf spring 41 unflexing as the pressure against the end cap 49 is removed. The door may therefore be opened more easily, without causing undue wear of the sealing element 61. Moreover, upon closure of the door, the sealing element 61 is forced into contact with the door sill only after the door is completely closed. Therefore, the door bottom may be adjusted to insure maximum travel of the sealing element 61 and thereby more effectively blocking the space between the door and the door sill. In addition, should the door or door sill become misaligned or misshapened, the adjustability feature of the weatherstrip allows the travel of the flexible element to be regulated to conform to the space to be blocked.
In order to make the automatic door bottom of the present invention seal more evenly, and to avoid premature contact of the seal with the adjacent floor or sill as the door closes one or two pair of magnets are used which act to cause one end of the flexible sealing element 61 to drop down into contact with the door sill before the other end thereof. A first pair of magnets 75 and 77 is located near the second slide block 39 and the end cap 49. The first magnet 75 of the pair is attached to the top wall 21 of the channel 13 by a compatable adhesive, or in any other convenient manner. The second magnet 77 of the pair is similarly affixed to the drop bar assembly 57. This first pair of magnets 75 and 77 is oriented such that they repel each other. A second pair of magnets 79 and 81 is located near the first slide block 37. The third magnet 79 is attached to the upper wall 21 of the channel 13 as was the first magnet 75. The fourth magnet 81 is attached to the drop bar assembly 57 as was the second magnet 77. This second pair of magnets is oriented so that they attract each other. Because of the repulsion of the first pair of magnets, the end of the sealing element 61 closest to the end cap 49 is forced out of the channel 13 first. Likewise, the attraction of the second pair of magnets retains the end of the sealing element 61 located near the first sliding block 37 in the channel 13 until after the rest of the sealing element 61 has been forced out of the channel 13. In this manner as the door is closed the portion of the sealing element 61 nearest the hinge side of the door frame drops down first onto the sill. The portion furthest from the inside of the door and which has not yet moved over the sill remains retracted so as not to rub on the adjacent floor or carpeting. It drops down as the door approaches its fully closed position, when that end of the sealing element has moved over the sill. Conversely, when the door is opened this outer end of element 61 retracts first.
Substantially the same function can be achieved by using only one pair repelling of magnets 75, 77 or by eliminating one of the attractive magnets, 79, 81 and substituting a steel plate or the like therefore.
The invention has one other unique and important feature: the door bottom is self leveling due to the unique spring arrangement and its connection with the drop bar assembly. The pivot pin simply interconnects the drop bar with the spring, and as the pushrod forces the spring to flex, it flattens out against the sealing element in the drop bar and the sealing element conforms to the floor.
While the invention has been described in considerable detail, it is not to be limited thereto except as necessitated by the appended claims.
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An automatic door bottom is disclosed in which a channel member has a drop bar assembly mounted therein with an adjustable length push rod connected to the drop bar for cooperation with a spring means to selectively lower and raise the drop bar in response to opening and closing the door. A pair of magnets are placed within the channel on the drop bar and in the channel for effecting movement of the drop bar to insure that the bar drops in a sizzle-like manner, with the end closest to the door hinge dropping down and lifting up, before the end away from the door hinge.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention concerns a monochromator for an X-ray device of the type having an X-ray source with a crystal for spectral restriction of the X-ray produced by the X-ray source. The invention also concerns an X-ray device that incorporates such a monochromator.
[0003] 2. Description of the Prior Art
[0004] X-rays are used in medical and technical diagnostics to obtain images of objects to be examined. The quality of images thus produced depends on the radiation dose and on the energy spectrum of the X-rays. In order to achieve a certain minimum image quality, a certain minimum radiation dose is required, and the minimum radiation dose itself depends on the spectral energy distribution in the X-rays. In addition, depending on the concrete body or object to be examined, there always exists an optimum level of X-radiation energy, i.e., the wavelength of the X-radiation at which a maximum contrast resolution with a simultaneous minimized radiation dose can be achieved. Thus, in order to achieve the requisite minimum image quality with a minimized radiation dose, X-radiation of a suitable spectrum must be used.
[0005] The spectral energy distribution of X-rays, however, can be influenced at the X-ray source only to a limited extent. For example, the energy spectrum of a conventional X-ray tube always contains wavelength components outside the wavelength that is optimal for the radiation dose and the contrast resolution. The energy spectrum of an X-ray tube is influenced by the choice of anode material and by the type of X-ray absorption filters used. Furthermore, the aforementioned energy spectrum also strongly depends on the X-ray voltage, i.e., the energy with which electrons inside the X-ray tube are accelerated from the cathode to the anode. The X-ray voltage determines the upper limit of the energy spectrum.
[0006] Changes in the X-ray voltage affect not only the energy spectrum, but also the radiation dose, because with decreasing X-ray voltage, the tube current, i.e., the electron flow inside the X-ray tube, decreases. Thus, in order to compensate for the reduction of the radiation dose with a decrease in X-ray voltage, we must increase the X-ray tube current. The increase of the X-ray tube current, however, is restricted by the so-called blooming effect, by which—due to a lower X-ray voltage and high X-ray currents—the X-ray focal spot on the anode of the X-ray tube enlarges. The blooming effect negatively affects the properties of the X-rays that are produced.
[0007] Currently, depending on the particular application, a suitable energy spectrum is achieved by an appropriate combination of the anode material, the X-ray absorption filters, and the X-ray voltage. Each energy spectrum thus is necessarily a compromise among the various parameters.
[0008] European Application 0 924 967 discloses an X-ray device with a monochromator designed on the basis of a so-called mosaic crystal. The mosaic crystal is arranged in the path of radiation beam in such a manner that the X-rays of the X-ray tube are reflected by it. On the basis of Bragg relation for the diffraction of X-rays, for a certain reflection direction spectrally restricted, i.e., quasi-monochromatized, X-rays are obtained. In order to obtain X-rays of various wavelengths, the aforementioned European application proposes to implement multiple mosaic crystals to provide various Bragg angles. The arrangement of multiple mosaic crystals and their associated diaphragms requires a number of components and is therefore costly. Moreover, this arrangement has the inherent drawback that different propagation paths are pre-determined for the X-rays, which have to be individually aimed at the particular object to be examined.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a monochromator for an X-ray device that makes it possible to variably spectrally restrict X-rays produced by an X-ray device using a reflection crystal, with such a monochromator being inexpensive to design and easy to operate.
[0010] The above object is achieved in accordance with the present invention by a monochromator for an X-ray device that comprises an X-ray source with a crystal for spectral restriction of the X-ray produced by the X-ray source, wherein, according to the invention, the crystal can be adjusted by a positioning device so that the energy spectrum of the spectrally restricted X-radiation can be changed. The ability to adjust the crystal provides the possibility of adjusting the energy spectrum of the spectrally restricted X-radiation to comply with the requirements for the image to be acquired without having to set the X-ray voltage and X-ray tube current to non-optimal values. For example, using this design the blooming effect that occurs at low X-ray voltages and high X-ray currents can be avoided, or the X-ray tube can always be operated with an X-ray voltage suitable for the particular requisite level of efficiency. At the same time, the adjustability of the crystal allows for a variable adjustment of the energy spectrum to various requirements without the need for changes in the X-ray source (for example, in the anode material).
[0011] In an embodiment of the invention, the crystal is adjustable so that the angle between the X-rays (produced by the X-ray source) and the crystal can be changed. According to the Bragg relation, the energy spectrum of the spectrally restricted X-radiation changes dependent on the change of the diffraction angle. Therefore, the ability to change the angle provides a simple and inexpensive means of producing X-radiation with variable energy spectra. Greater changes in the angle, which can be achieved, for example, by tilting the crystal, change the entire X-ray path. However, such changes can be simply compensated for, e.g., by a simultaneous tilting of the X-ray source. The tilting of the crystal performed together with a coordinated tilting of the X-ray source allows for a simple continuous variation of the energy spectrum of X-radiation with an unchanged X-ray path.
[0012] In another embodiment of the invention, the crystal can be adjusted so that it can be fully removed from and returned into the X-ray path produced by the X-ray source. If the crystal is removed from the X-ray path, Bragg diffraction of the X-ray is prevented, and the original energy spectrum of the X-ray source is reconstituted. Thus, the option of removing and then returning the crystal to the X-ray path provides a simple way of producing either spectrally restricted X-rays or X-rays without any spectral restriction. If, during the removal of the crystal, certain adjustments have to be made to reflect the change in the entire X-ray path, for example, by tilting the X-ray source, this is easy to do.
[0013] In another embodiment of the invention, the crystal can be automatically adjusted so that we reach a maximum value of the energy spectrum of the spectrally restricted X-radiation is reached that is between 0.34- and 0.8-multiples of the maximum value of the original (unrestricted) energy spectrum of the X-ray source. The original energy, which is greater than in the spectrally restricted X-radiation, is produced by an increased X-ray voltage, which means the blooming effect is reduced. At the same time, by maintaining a minimal factor of about 0.34, the influence of higher-order reflection in the energy spectrum of the spectrally restricted X-radiation is minimized. Higher-order reflection occurs at double, triple, quadruple, etc. the minimum value of the original X-radiation. The indicated range rules out the possibility that reflections from the 3rd order and beyond will be contained in the spectrally restricted X-radiation.
DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 shows an X-ray device with a monochromator in accordance with this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The figure illustrates an X-ray device 3 with a monochromator 1 in accordance with the invention. The monochromator 1 is an accessory device that is connected to the X-ray source 5 as a module; however, the device can also be fully integrated with the X-ray sources. Other components of the X-ray tube, such as a diaphragm, are not essential to the explanation of the invention and therefore are not illustrated.
[0016] The X-ray device 3 produces spectrally restricted X-radiation 11 in order to generate an image of a patient 29 lying on a patient positioning table 27 . Depending on the type of the required X-ray image, the X-ray path of X-radiation 11 can assume various orientations by moving and turning the X-ray source 5 mounted on the ceiling stand. This also allows examination of, for example, a standing patient, with the monochromator 1 always being used in the same manner.
[0017] A voltage generator 19 , which is connected to the X-ray source 5 by an electrical line 23 , generates the X-ray voltage and the X-ray tube current to operate the X-ray source 5 . The X-ray generator 19 is controlled by a control device 17 , which is connected to the X-ray generator 19 by a control line 21 . The control device 17 allows entry of all the parameters of the X-ray image that is to be produced.
[0018] The basic component of the monochromator 1 is a crystal 7 , which reflects X-rays propagating in an X-ray path 9 . The reflection at the crystal 7 produces spectrally restricted X-radiation 11 , the energy spectrum of which depends on the angle of the reflection. The maximum value of the energy spectrum of the spectrally restricted X-radiation 11 follows from the Bragg relation as follows:
sin Θ = k · λ 2 · a
[0019] where Θ represents the angle between the X-ray path 9 and the crystal 7 , k is a natural number and denotes the order of the reflection, I represents the wavelength of the maximum value of the energy spectrum of the spectrally restricted X-radiation 11 , and a represents a property of the crystal lattice of the crystal 7 .
[0020] Bragg reflection of the X-ray by crystals produces X-radiation at a relatively narrow peak in the energy spectrum for each reflection order k. While such a narrow energy spectrum can be advantageous for many applications, it presents the problem of a relatively low radiation dose. Therefore, a widening of the energy spectrum and thus a widening of its peak in the range of the maximum value must be accepted in order to reach an accordingly increased radiation dose. For this reason, a mosaic crystal is as the preferred type of the crystal 7 for medical X-ray devices. The preferred type of the crystal 7 is a mosaic crystal made of layers of highly oriented pyrolytic graphite (HOPG). The direction in space of the crystal lattice should vary around 1°.
[0021] Due to different lattice orientations of the crystal molecules or atoms represented by the factor a of the aforementioned Bragg's relation, mosaic crystals produce an energy spectrum that is widened very slightly. Spectrally restricted X-radiation with a peak widened in this manner will reach the radiation doses required in medical diagnostics.
[0022] The energy spectrum of the spectrally restricted X-radiation 11 can be changed by changing the angle of incidence Θ of the X-ray 9 on the crystal 7 . For this purpose, the crystal 7 can be tilted using a positioning device that includes a tilting arrangement 13 . However, this tilting changes not only the angle of incidence Θ, but also the reflection angle. Because of this correspondent change, the ray path of the spectrally restricted X-radiation 11 changes too, so that its focus can shift. In the case of small changes in the angle of incidence Θ this effect plays only a minor role, but a substantial change of the angle can result in the focus leaving the intended (and targeted) zone of the patient 29 to be examined. This means that after larger changes occur in the energy spectrum due to the tilting of the crystal 7 , the region to be examined must be targeted again. In order to avoid this problem, the crystal 7 can be tilted simultaneously with the X-ray source 5 or with the entire arrangement of the X-ray source 5 and the monochromator 1 so that this process compensates for any change in the ray path. Since, in order to be able to target any possible section of a patient 29 to be examined, the X-ray source 5 usually is arranged so that it can be fully moved in all directions in space, all that is required to compensate for a tilting movement of the crystal 7 is to perform a coordinated tilting of the X-ray source 5 .
[0023] Since the crystal 7 and the X-ray source 5 must be movable in relation to each other only in one plane, in order to influence the angle Θ, quite simple angle ratios are obtained. The simple angle ratios allow us to perform the compensation for the tilting movement of the crystal 7 either by an independent control of the tilting movement of the X-ray source 5 , or by providing a mechanism for coupling the tilting movements of the crystal 7 with the X-ray source 5 . The implementation of such possibilities is within the capabilities of those of ordinary skill in the art.
[0024] The omni-directional adjustability of the X-ray source 5 can be implemented by any of a number of conventional ways. The crystal 7 can be tilted by the tilting arrangement 13 so that the angle of incidence Θ of the X-ray path 9 changes. In the illustration in the figure, the tilting motion of the crystal 7 occurs in one of the planes in the drawing plane. Due to a rigid spatial arrangement of the X-ray source 5 and the monochromator 1 , the angle Θ can be changed only by tilting the crystal 7 . However, in an alternative arrangement, the crystal 7 can be rigidly mounted in space within the monochromator 1 , and the X-ray source 5 can be tilted relative to the monochromator 1 . As previously described, in another variant the crystal 7 and the X-ray source 5 are always tilted simultaneously so that the ray path of the spectrally restricted radiation 11 remains spatially unchanged and thus the focus of the ray path does not shift.
[0025] Another possible adjustment of the crystal 7 is to fully remove the crystal 7 from the X-ray path 9 or to return it using a shifting device 15 . By doing this, the influence of the crystal 7 changes so that Bragg reflection of the X-ray path 9 is quite eliminated. The X-rays in the X-ray path 9 then have the original energy spectrum determined by the X-ray source 5 and its operation parameters. The option of removing the crystal 7 allows operation either with spectrally restricted X-radiation or with unrestricted X-radiation depending on the type of the required image. In addition, removing or returning the crystal 7 to the X-ray path 9 changes the entire ray path, which can be compensated for in the above-described manner. The parameters defining the energy spectrum of the spectrally restricted X-radiation 11 are set in the control device 17 . In accordance with the invention, these parameters include, besides the X-ray voltage and the X-ray current, the tilt angle of the crystal 7 and the positioning in or outside the X-ray path 9 . The line 23 conducts the signals from the control device 17 that to control the movements of the ceiling stand 25 and positioning of the crystal 7 as well as, if necessary, of the X-ray source 5 . Thus, the control device 17 controls the positioning device, i.e., the tilting arrangement 13 , and the shifting device 15 . Therefore, the control device 17 can coordinate the tilting movement of the X-ray source 5 with the tilting movement of the crystal 7 in the above-described way so that the beam path of the X-radiation 11 remains uncharged and its focus does not shift.
[0026] Selection of the angle of incidence Θ of the X-ray path 9 on the crystal 7 , should be based on a voltage as high as possible, because the efficiency of an X-ray tube used as the X-ray source 5 increases with the square of the X-ray voltage. The utilization of Bragg reflection according to the invention makes it possible to produce X-radiation of relatively low energy levels with a simultaneous high efficiency of the X-ray source 5 . In addition, the relatively high X-ray voltage reduces the blooming effect, which causes enlargement of the focal spot. In order to be able to utilize these advantageous effects enabled by the increased X-ray voltage, the incidence angle Θ is set so that the maximum value of the energy spectrum of the monochromatized X-radiation 11 is not greater than the 0.8-multiple of the maximum value of the energy spectrum of the X-ray 9 .
[0027] Besides the maximum value of the energy spectrum in the reflected X-ray, Bragg reflection contains maxima of higher order as expressed by the factor k in the Bragg relation. In order to keep the influence of the refractions of higher order in the reflected X-ray small, the maximum value of the energy spectrum of the monochromatized X-radiation 11 is set to no less than the 0.34-multiple of the maximum value of the energy spectrum of the X-ray path 9 . This guarantees especially that refraction from the 3 rd order on do not enter the monochromatized X-radiation 11 .
[0028] Adherence to the described upper and lower limits can be automatically ensured using the control device 17 . In addition, the control device 17 can automatically set the angle Θ so that after the definition of the X-ray voltage or a maximum value for the energy spectrum of the spectrally restricted X-radiation 11 or a factor between the maximum values of the energy spectrum of the X-ray path 9 and the spectrally restricted X-radiation 11 , the operation of the X-ray device occurs with optimal efficiency, as low blooming effects as possible or with other parameters optimized. In this way, the control of the monochromator 1 and the X-ray source 5 is substantially automated thus utilizing the resulting advantages, which include no need for an operator to enter special parameters. Moreover, depending on the type of the required image to be produced,. the control device 17 can remove the crystal 7 from the X-ray 9 or return it.
[0029] On the basis of the optical law of reflection, this invention can be used with advantage especially in applications using a fan ray, e.g., line scanners in CT apparatuses, and in applications that scan a whole area, e.g., angiography of extremities.
[0030] Although modifications and changes 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.
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A monochromator to be used in an X-ray device having an X-ray source is formed by a crystal for spectral restriction of X-rays produced by the X-ray source. The monochromator includes a positioning device that can move the crystal so that it changes the spectral composition of the X-radiation. The crystal can be moved so that it changes the angle between an X-ray path and the crystal, or so that the crystal is removed out of X-ray path or returned into it.
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TECHNICAL FIELD
The present invention is generally related to magnetostatic modeling methods and systems. The present invention is also related to methods and systems for modeling magnetic and ferrous objects. The present invention is additionally related to boundary element modeling methods and systems.
BACKGROUND OF THE INVENTION
The energy present in a magnetostatic structure has been used in a wide range of applications, including magnetic sensors utilized in a variety of technical and commercial applications, including in particular, automotive applications. The generation of a voltage in a conductor by the changing of a magnetostatic structure or the movement of a magnetostatic structure relative to the conductor is a well-known concept. The aforementioned conductors commonly use a permanent magnet made of electrically conducting metal.
In the development of magnetic sensors, it is often necessary to create various types of magnetic sensor data processing algorithms and systems capable of localizing, quantifying, and classifying such objects based on their magnetostatic fields. In general, a magnetostatic field may be generated by any combination of three physical phenomena: permanent or remanent magnetization, magnetostatic induction, and electromagnetic induction. The first phenomena can occur in objects that contain metals of the ferromagnetic group, which includes iron, nickel, cobalt, and their alloys. These may be permanently magnetized either through manufacture or use. Second, fields external to the object may induce a secondary field in ferromagnetic structures and also paramagnetic structures if the mass and shape sufficiently enhance the susceptibility. Third, the object may comprise a large direct current loop that induces its own magnetic field.
Many of the current magnetostatic modeling methods applicable to magnetic sensor development rely upon boundary element modeling software. Such software generally utilizes both direct and indirect boundary element methods as well as finite element methods to accurately model magnetic properties of various structures/solids and their interaction with surrounding components. The boundary element method has become an important technique in the computational solution of a number of physical problems. In common with the better-known finite element method and finite difference method, the boundary element method is essentially a mathematical and algorithmic technique that can be utilized to solve partial differential equations. Boundary element techniques generally have earned the important distinction that only the boundary of the domain of interest requires discretisation. For example, if the domain is either the interior or exterior to a sphere, then the resulting diagram will depict a typical mesh, and only the surface is generally divided into elements. Thus, the computational advantages of the boundary element technique over other methods can be considerable, particularly in magnetic modeling applications.
One particular modeling software and its associated algorithms and software modules that have been utilized by the present inventor at Honeywell is referred to collectively as “Narfmm”. Such magnet models generally have always assumed a relative permeability (i.e., μ in units of Gauss/Oersted) equal to one. This assumption results in magnet models with “magnetic charge” residing only on the surface of the magnet. This is a good approximation for magnet materials such as sintered SmCo and NdFeB that have μ between 1 and 1.1. For magnet materials, however, with a greater μ, such as NdFeB powder in plastic with μ equal to 1.3, assuming μ equal to one, large errors typically can result. Also for nonlinear BH curve materials, such as AlNiCo, magnetostatic models such as Narfmm models can result in a substantial error. For ferrous objects, magnetostatic models such as Narfmm generally assume infinite permeability, which forces the “magnetic charge” to reside only on the surface of the ferrous object. If this is not a good assumption, software models such as Narfmm models have been inadequate.
Based on the foregoing, the present inventor has concluded that a more accurate model for magnets and ferrous objects should have a varying surface charge density at the magnetic object surface and also a varying magnetic charge distributed throughout the volume of the magnetic object. The present invention thus improves modeling accuracy by describing a method for modeling magnets and ferrous objects, which have any defined BH curve within modeling methods, such as, for example, the Narfmm software, thereby eliminating prior art limitations.
BRIEF SUMMARY OF THE INVENTION
The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide a method and system for accurately and efficiently modeling a magnetic object.
It is another aspect of the present invention to provide a method and system for accurately and efficiently modeling a ferrous object.
It is yet another aspect of the present invention to provide an improved magnetostatic modeling method and system.
It is still another aspect of the present invention to provide an improved magnetostatic modeling method and system for use with boundary element modeling.
Methods and systems for magnetostatic modeling of a magnetic object are disclosed herein. A varying surface charge density is established at a surface of a magnetic object modeled by a magnetostatic model. Thereafter, a varying magnetic charge is generally distributed throughout a volume of the magnetic object to thereby accurately and efficiently model the magnetic object across a wide range of magnetic curves utilizing the magnetostatic model. The magnetic curves can be configured to generally comprise at least one non-linear magnetic curve and/or at least one linear magnetic curve. Such magnetic curves may also comprise at least one magnetic curve in a magnetized direction and/or non-magnetized direction. Such magnetic curves are generally referred to herein as “BH curves”.
The magnetostatic model may be created using a magnetostatic-modeling module (e.g., software) such as, for example, boundary element-modeling module software. The magnetic object to be modeled can be a magnet or another ferrous object. The magnetic object to be modeled can also be an anisotropic magnet. The magnetostatic modeling methods and systems described herein can be applied to magnets with a large μ, such as NdFeB-based magnets and non-linear BH curve materials such as AlNiCo, or to any value of μ. The present invention thus discloses a method and system for accurately and efficiently modeling magnets and ferrous objects, which have any defined BH curve with a magnetostatic model such as can be derived from magnetostatic-modeling software.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
FIG. 1 depicts a graph illustrating a BH curve of a magnet and BH curve of magnet elements, in accordance with a preferred embodiment of the present invention;
FIG. 2 depicts a graph illustrating a BH curve of a magnet and a BH curve of magnet elements in a magnetized Z-direction, in accordance with a preferred embodiment of the present invention;
FIG. 3 depicts a graph illustrating a BH curve of a magnet and a BH curve of magnet elements in a non-magnetized direction, in accordance with a preferred embodiment of the present invention;
FIG. 4 depicts a graph illustrating a BH curve of a magnet and a BH curve in the magnetized Z-direction of the magnet to be modeled, in accordance with a preferred embodiment of the present invention;
FIG. 5 depicts a graph illustrating a BH curve of a magnet and a BH curve of magnet elements in a non-magnetized X-direction, in accordance with a preferred embodiment of the present invention;
FIG. 6 depicts a first iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention;
FIG. 7 depicts a second iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention;
FIG. 8 depicts a third iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention.
FIG. 9 illustrates a pictorial representation of a data processing system, which may be utilized in accordance with the method and system of the present invention; and
FIG. 10 depicts a block diagram illustrative of selected components in a computer system, which can be utilized in accordance with the method and system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate an embodiment of the present invention and are not intended to limit the scope of the invention.
FIG. 1 illustrates a graph 100 illustrating a BH curve 102 of a magnet and BH curve 104 of magnet elements, in accordance with a preferred embodiment of the present invention. BH curve 102 is a BH curve of a magnet to be modeled, according to Eq. (1) B=α·H+B r wherein α=B r /H c . BH curve 104 represents a BH curve for an n th magnet element based on the formulation of B=H+M n such that an intersection point 106 exists between BH curve 102 and BH curve 104 . The intersection point 106 is equal to (B n , H n ), wherein B n represents the magnetic flux density at the n th magnet element (Gauss), and H n represents the magnetic field intensity at the n th magnet element (Oersted). BH curve 102 generally crosses axis 110 at point 114 (i.e., B r ), and the axis 112 at point 118 (i.e., −H c ). BH curve 104 crosses axis 110 at point 116 (i.e., M n ). In general, the magnet to be modeled has a BH curve 102 as shown in FIG. 1 and Equation (1).
B=α·H+B r (1)
In general, B represents the magnetic flux density (Gauss); α represents the slope of the line and also the μ of the magnet (Gauss/Oersted); H represents the magnetic field intensity (Oersted); and B r represents the residual induction (Gauss). H c represents the coercive force (Oersted). In this model the μ variable is generally equal to the α variable only in the magnetized direction. The variable μ in the non-magnetized direction is equal to unity.
The magnet volume is generally divided into volume elements. Each n th volume element is itself a magnet that will be modeled with a standard magnet model such as Narfmm with a BH curve shown 104 in FIG. 1 and equation (2).
B=H+M n (2)
Note that although the present invention is discussed and illustrated herein with respect to a standard magnetostatic modeling software package such as Narfmm, those skilled in the art can appreciate that such a magnetostatic modeling mechanism or module is not a limiting feature of the present invention but represents an illustrative example only of one modeling system to which the present invention may apply. Narfmm is thus presented herein for general illustrative and edification purposes only, and other modeling software packages or methodologies can be employed.
With respect to Equation (2), B represents the magnetic flux density (Gauss); H represents the magnetic field intensity (Oersted); and M n represents the residual induction of the n th magnet element (Gauss).
In order to model the magnet, the value of M n for each n th volume element is determined. Each magnet element will lie somewhere on the actual BH curve line 102 shown in FIG. 1 with respect to Equation (1). The magnet element can be modeled with the μ equal to one BH curve as determined in Equation (2) if the proper M n can be determined. If the intersection point 106 (B n ,H n ) is known, M n can be determined as shown in Equation (3), since the slope is equal to one.
M n =B n −H n (3)
With respect to Equation (3), once all of the M n results are known, a standard Narfmm magnet model (i.e., modeling software) can be used for each magnet element, summing all of the magnet elements' contributions through superposition to obtain the magnetic field from the whole magnet. The standard Narfmm magnet model refers to a magnet model wherein the magnetic charge resides completely on the surface of the magnet element, which is easier to model in comparison to a distribution throughout the volume.
The defining relation for the flux density inside a magnet with μ equal to one is:
B=μ·H+M+B e (4)
With respect to Equation (4), B represents the magnetic flux density (Gauss); μ represents the relative permeability, which is equal to one (Gauss/Oersted); H represents the magnetic field strength (Oersted); M represents the residual magnetic induction (Gauss); and B e represents the magnetic flux density from sources external to the magnet (Gauss).
For the n th magnet volume element, using Equation (4) and replacing μ with 1, Equation (5) results as indicated below.
B n =H n +M n +B en (5)
With respect to Equation (5), B en represents the magnetic flux density in the magnetized direction on magnet element n from the other magnet sources external to the magnet element (Gauss). Note that the center of the magnet volume element is used as the field point to determine the BH curve's intersection point in all equations. The larger the number of magnet elements, the smaller the element size, and the smaller the error associated with subdividing the magnet into a finite number of sections. Any arbitrary level of accuracy can be obtained by increasing the number of magnet elements to the proper level.
Additionally, H n can be expressed in normalized terms as indicated in Equation (6) below.
H n =M n ·H Nn (6)
With respect to Equation (6), H Nn generally represents the normalized H in the magnetized direction at the center of the n th magnet element (Oersted/Gauss).
H Nn is calculated with the standard Narfmm magnet equations by letting the residual induction be equal to unity.
B
en
=
∑
m
=
1
m
≠
n
P
M
m
·
B
Nmn
(
7
)
With respect to Equation (7), P represents the total number of magnet elements; and B Nmn represents the normalized magnetic flux density from magnet element m to magnet element n in the magnetized direction (unitless). B Nmn is calculated with the standard Narfmm magnet equations by letting the residual induction of magnet element m be equal to unity. Thus, substituting Equation (6) and Equation (7) into Equation (5) yields the formulation of Equation (8), as indicated below.
B
n
=
M
n
·
H
Nn
+
M
n
+
∑
m
=
1
m
≠
n
P
M
m
·
B
Nmn
(
8
)
Combining Equation (1) and Equation (2) to determine the intersection point of the two BH curve lines, and solving for B n yields the following Equation (9).
B
n
=
B
r
-
α
·
M
n
(
1
-
α
)
(
9
)
Combining Equation (8) and Equation (9) to eliminate B n yields Equation (10).
B
r
-
α
M
n
(
1
-
α
)
=
M
n
·
H
Nn
+
M
n
+
∑
m
=
1
m
≠
n
P
M
m
·
B
Nmn
(
10
)
In Equation (10) there are P equations with P unknowns. The P unknowns are M n . A linear set of equations results from Equation (10) that can be transformed into matrix form as shown in Equation (11).
Ψ×Φ=Γ (11)
With respect to Equation (11), ψ represents a P×P matrix of known values. φ represents a P×1 matrix, with elements M 1 through M p represents a P×1 matrix of known values.
To solve for the variable M n for use in the magnet model, a solution for φ is achieved, as illustrated in Equation (12) below.
Φ=Ψ −1 ×Γ (12)
The diagonal elements of ψ are provided in Equation (13).
Ψ
nn
=
H
Nn
+
1
+
α
1
-
α
(
13
)
The off diagonal elements of ψ are provided in Equation (14).
Ψ nm =B Nmn for m≠n (14)
In Equation (13) and Equation (14), the subscript index on ψ indicates the row and column number of the matrix respectively. Each element of is the same and is provided in Equation (15).
Γ
n
=
B
r
1
-
α
(
15
)
FIG. 1 thus generally illustrates and describes a method that can be utilized to model magnets with a constant μ greater than one in modeling software, such as, for example, Narfmm. Those skilled in the art can appreciate that the Narfmm software discussed herein is not a limiting feature of the present invention. Such software is only described herein in the context of a representative embodiment in which the present invention may preferably be embodied. Those skilled in the art will appreciate, however, that the methodology described herein is applicable to a wide variety of modeling software applications.
This aforementioned modeling methodology can be utilized to model block magnets, but it can be adapted for use with any magnet of any shape or size. Also, such a methodology allows μ greater than one only in the magnetized direction. Off the magnetization axis, μ is one. However the same principles can apply in order to create a model with μ greater than one in the other two orthogonal directions. With respect to the implementation described with respect to FIG. 1 , the volume magnetic charges are represented by rectangles of constant charge density. To decrease computation time, the volume poles can be represented with point charges for most applications. This methodology can be adapted to more complex BH curves, such as AlNiCo magnets, which have BH curves that can be closely approximated with a second order polynomial such as indicated in Equation (16) below.
B=β·H 2 +α·H+B r (16)
The same basic approach discussed above can be utilized to set up the P equations and P unknowns by replacing Equation (1) with Equation (16). However, the solution cannot be placed into the form of Equation (12), so another mathematical or numeric method is required to solve for M in that case. Magnets having BH curves such as those resulting from Equation (16) can be addressed using the methodology following Equation (32).
FIG. 2 depicts a graph 200 depicting a BH curve 202 of a magnet and a BH curve 204 of magnet elements in a magnetized Z-direction, in accordance with a preferred embodiment of the present invention. Graph 200 also includes an axis 210 and an axis 212 . BH curve 202 represents the actual BH curve in the magnetized Z-direction of a magnet to be modeled. BH curve 202 is modeled according to the formulation B=α z ·H z +B rz wherein α z =B r /H c . BH curve 204 represents a BH curve for an n th magnet element in the Z-direction based on the formulation of B z =H z +Mz zn such that an intersection point 206 (i.e., B zn H zn ) exists between BH curve 102 and BH curve 104 . BH curve 202 crosses axis 210 at point 214 (i.e., B rz ) and axis 212 at point 218 (i.e., −H c ). BH curve 204 crosses axis 210 at point 216 (i.e., M zn ). Point 220 represents originating coordinates (0,0) of graph 200 .
FIG. 3 illustrates a graph 300 illustrating a BH curve 306 of a magnet and a BH curve 302 of magnet elements in a non-magnetized direction, in accordance with a preferred embodiment of the present invention. Graph 300 includes an axis 310 and an axis 312 and originating point 320 with coordinates of (0,0). According to graph 300 , B rx =0, as shown at point 320 . BH curve 302 represents a BH curve for the n th magnet element in the X direction, wherein B x =H x +M n . BH curve 306 , on the other hand, represents the actual BH curve of the magnet to be modeled in a non-magnetized X direction, wherein B x =α x ×H x . An intersection point 304 exists between BH curve 302 and BH curve 306 wherein the intersection point is equal to (B nx , H nx ). BH curve 302 crosses axis 310 at point 316 , while BH curve 304 crosses point 320 .
As indicated earlier, a method for modeling a magnet with permeability (μ) greater than one in the magnetized direction within modeling software can be implemented in accordance with the methodology of the present invention. FIGS. 2 and 3 expand on that method by describing a method for modeling a magnet with μ greater than one in both the magnetized and non-magnetized directions. The magnet to be modeled thus has BH curves 202 and 306 as respectively illustrated in FIGS. 2 and 3 and additionally described with respect to Equation (17) below. Thus, assume the magnet is magnetized in the z direction.
B x =α x ·H x
B y =α y ·H y
B z =α z ·H z +B rz (17)
The x, y and z subscripts indicated in Equation (17) above generally denote spatial direction. B represents the magnetic flux density (Gauss). Additionally, α represents the slope of the line, and also the μ of the magnet (Gauss/Oersted). H represents the magnetic field intensity (Oersted), and B r represents the residual induction (Gauss).
The magnet volume is divided into volume elements. Each n th volume element is itself a magnet that will be modeled with a standard magnet model (e.g., Narfmm) having BH curves 202 and 306 as respectively illustrated in FIGS. 1 and 2 . The equations are provided in Equation (18).
B x =H x +M xn
B y =H y +M yn
B z =H z +M zn (18)
With respect to Equation (18), B represents the magnetic flux density (Gauss), and H represents the magnetic field intensity (Oersted). The variable M n represents the residual induction of the n th magnet element (Gauss). A standard Narfmm magnet volume, for example, includes a constant “magnetic charge” density at the surface of the magnet on the North (positive charge) and South (negative charge) poles. The BH curves thus intersect at the points (B xn ,H xn ), (B yn ,H yn ), (B zn ,Hn zn ), wherein B n represents the magnetic flux density at the n th magnet element (Gauss), and H n represents the magnetic field intensity at the n th magnet element (Oersted).
In order to model the magnet, the values for M xn , M yn and M zn for each n th volume element are determined. Each magnet element will lie somewhere on the actual BH curve line indicated by Equation (17). The magnet element can be modeled with the “μ equal to one BH curve” indicated in Equation (18) if the proper M xn , M yn and M zn can be determined. If the intersection points (B xn ,H xn ), (B yn ,H yn ), (B zn ,H zn ) are known; M xn , M yn and M zn can be determined, since the slope is equal to one. Equation (19) below thus represents this formulation.
M xn =B xn −H xn
M yn =B yn −H yn
M zn =B zn −H zn (19)
Once the M xn , M yn and M zn are known, a standard magnet model (e.g., Narfmm) can be utilized for each magnet element, summing all of the magnet elements' contributions through superposition to obtain the magnetic field from the whole magnet. The defining relation for the flux density inside a magnet with μ equal to one is:
B=μ·H+M+B e (20)
With respect to Equation (20), B represents the magnetic flux density (Gauss), and μ represents the relative permeability, which is equal to one (Gauss/Oersted). Additionally, H represents the magnetic field intensity (Oersted), and M represents the residual magnetic induction (Gauss). B e represents the magnetic flux density from sources external to the magnet (Gauss).
For the n th magnet volume element, Equation (21) can be obtained by using (20) and replacing μ with 1.
B xn =H xn +M xn +B xen
B yn =H yn +M yn +B yen
B zn =H zn +M zn +B zen (21)
B xen , B yen , B zen are the magnetic flux densities in the indicated direction on magnet element n from the other magnet elements (Gauss). Note that the center of the magnet volume element is used as the field point to determine the BH curve's intersection point in all equations. The larger the number of magnet elements, the smaller the element size, and the smaller the error associated with subdividing the magnet into a finite number of sections. Any arbitrary level of accuracy can be obtained by increasing the number of magnet elements to the proper level.
H xn , H yn , H zn can be expressed in normalized terms as shown in Equation (22).
H xn =M xn ·H xNn
H yn =M yn ·H yNn
H zn =M zn ·H zNn (22)
With respect to Equation (22), H xNn , H yNn , H zNn are the normalized H in the indicated direction at the center of the n th magnet element (Oersted/Gauss). H Nn is calculated with the standard Narfmm magnet equations by letting the residual induction be equal to unity. B xen , B yen , B zen can be expressed as a summation, as indicated in Equation (23).
B
xen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
B
yen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
B
zen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
(
23
)
With respect to Equation (23), the subscript on the B indicates the sub magnet orientation and the field direction. For example, “yx” on the B refers to a field in x direction from the y facing magnet element. P represents the total number of magnet elements. B Nmn represents the normalized magnetic flux density from magnet element m to magnet element n in the magnetized direction (no units). B Nmn is calculated with standard magnet modeling equations (e.g., Narfmm) by letting the residual induction of magnet element m be equal to unity. Substituting Equation (22) and Equation (23) into Equation (21) thus yields Equation (24).
B
xn
=
M
xn
·
H
xNn
+
M
xn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
B
yn
=
M
yn
·
H
yNn
+
M
yn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
B
zn
=
M
zn
·
H
zNn
+
M
zn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
(
24
)
Combining Equations (17) and (18) to determine the intersection point of the two BH curve lines, and solving for B n yields Equation (25).
B
xn
=
-
α
x
·
M
xn
(
1
-
α
x
)
B
yn
=
-
α
y
·
M
yn
(
1
-
α
y
)
B
zn
=
B
zr
-
α
z
·
M
zn
(
1
-
α
z
)
(
25
)
Combining Equations (24) and (25) to eliminate B n yields Equation (26).
α
x
M
xn
(
1
-
α
x
)
=
M
xn
·
H
xNn
+
M
xn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
α
y
M
yn
(
1
-
α
y
)
=
M
yn
·
H
yNn
+
M
yn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
B
rz
-
α
z
M
zn
(
1
-
α
z
)
=
M
zn
·
H
zNn
+
M
zn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
(
26
)
In Equation (26) there are 3xP equations with 3xP unknowns since n takes on values from 1 to P. The 3xP unknowns are M xn , M yn and M zn . A linear set of equations comes from Equation (26) that can be transformed into matrix form.
Ψ×Φ=Γ (27)
Generally, ψ can represent a 3×P rows by 3×P columns matrix of known values. φrepresents a 3×P rows by 1 columns matrix, with elements M x1 through M xP , M y1 through M yP and M z1 through M zP . The variable can represent a 3xP rows by 1 column matrix of known values. To solve for the M xn , M yn and M zn to use in the magnet model, solve for φ.
Φ=Ψ −1 ×Γ (28)
The diagonal elements of ψ are given in Equation (29).
Ψ kk = H xNk + 1 + α x 1 - α x for k = 1 to P Ψ kk = H yN ( k - P ) + 1 + α y 1 - α y for k = P + 1 to 2 · P Ψ kk = H zN ( k - 2 P ) + 1 + α z 1 - α z for k = 2 · P + 1 to 3 · P ( 29 )
Each row of ψ, excluding the diagonals, is given in Equation (30).
Ψ kj =B xxNjk for k= 1 to P and j= 1 to P and k≠j Ψ kj =B yxNj(k−P) for k=P+ 1 to 2· P and j= 1 to P and k≠j Ψ kj =B zxNj(k−2·P) for k= 2· P+ 1 to 3· P and j= 1 to P and k≠j Ψ kj =B xy(j−P)k for k= 1 to P and j=P+ 1 to 2· P and k≠j Ψ kj =B yyN(j−P)(k−P) for k=P+ 1 to 2· P and j=P+ 1 to 2· P and k≠j Ψ kj =B zyN(j−P)(k−2 P) for k= 2· P+ 1 to 3· P and j=P+ 1 to 2· P and k≠j Ψ kj =B xzN(j−2 P)k for k= 1 to P and j= 2· P+ 1 to 3· P and k≠j Ψ kj =B yzN(j−2 P)(k−P) for k=P+ 1 to 2· P and j= 2· P+ 1 to 3· P and k≠j Ψ kj =B zzN(j−2 P)(k−2 P) for k= 2· P+ 1 to 3· P and j= 2· P+ 1 to 3· P and k≠j (30)
In Equations (29) and (30), the subscript index on ψ indicates the row and column number of the matrix element respectively. Each element of is given in Equation (31) below.
Γ
k
=
0
for
k
=
1
to
2
·
P
Γ
k
=
B
zr
1
-
α
z
for
k
=
2
·
P
+
1
to
3
·
P
(
31
)
FIGS. 2 and 3 thus generally depict a method for modeling a magnet with μ greater than one in both the magnetized and non-magnetized directions in a modeling software (e.g., Narfmm). Note that although the methodology described herein can be implemented in the context of a software programming tool such as, for example, Matlab, it can be appreciated by those skilled in the art that such a methodology may be implemented via any programming language, such as C or Fortran or via analog or digital circuitry. As indicated previously, although this model is primarily intended for use in modeling a block magnet, but it can be adapted for use in modeling any magnet of any shape or size.
Additionally, although the magnetization direction described above is in the z direction, the magnet can be magnetized in any direction by appropriately specifying (α x , α y , α z ) and (B rx , B ry , B rz ).
In software models, the ferrous objects have an infinite permeability that is usually a good approximation for systems having the permanent magnet and ferrous object separated from each other and the area of interest where the magnetic field is calculated is in the space between the magnet and the ferrous object. If the need were to arise though, the method described earlier used to model permeability greater than one in the non-magnetized direction of the magnet can be used to model ferrous objects with permeability less than infinity.
FIG. 4 depicts a graph 400 depicting a BH curve 402 of a magnet and a BH curve 404 for an n th magnet element in the magnetized Z-direction of the magnet to be modeled, in accordance with a preferred embodiment of the present invention. Graph 400 includes an axis 410 perpendicular to an axis 412 . BH curves 402 and 404 intersect one another at intersection point 406 (B zn , H zn ). BH curve 404 intersects axis 410 at point 416 (M zn ). An originating point 420 (0,0) is positioned at the intersection of axis 410 and 412 . BH curve 402 thus represents the actual BH curve in the magnetized Z direction of a magnet to be modeled: F z . BH curve 404 represents a BH curve for the n th magnet element in the Z direction, wherein B z =H z +M zn .
FIG. 5 illustrates a graph illustrating a BH curve 504 of a magnet to be modeled and a BH curve 502 of magnet elements in a non-magnetized X-direction, in accordance with a preferred embodiment of the present. invention. Note that the BH curve in the Y direction is essentially analogous to the BH curve in the X direction. An axis 510 intersects an axis 512 at an originating point 520 (0,0). BH curve 504 thus represents the actual BH curve of the magnet to be modeled in a non-magnetized X-direction: F x . BH curve 502 represents a BH curve for the n th magnet element in the X-direction, wherein B x =H x +M xn . BH curves 504 and 502 intersect one another at intersection point 506 (B xn , H xn ). BH curve 502 also intersects axis 510 at point 516 (M xn ).
FIG. 6 depicts a graph 600 illustrating a first iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention. FIG. 6 depicts an axis 612 and an axis 610 , which intersect one another at an origination point 620 (0,0). As indicated by graph 600 of FIG. 6 , an intermediate BH curve 604 for a first iteration crosses axis 610 at point 606 , which comprises a tangent point between an intermediate BH curve and the actual BH curve for the first iteration in which B z =a zn *H z +b z . BH curve 604 also intersects a BH curve 609 at intersection point 602 (i.e., intersection point, iteration 1). Note that graph 600 also illustrates a tangent point 608 for a second iteration for a curve 611 . Tangent point 608 is selected as a point on BH curve 611 close to point 602 . In this example, the close point is selected by going the smallest horizontal distance from point 602 to BH curve 611 , thus arriving at point 602 as indicated by arrow 615 . Note that BH curve 609 intersects axis 610 at point 614 (i.e., M zn , iteration 1).
FIG. 7 depicts a graph 700 illustrating a second iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention. FIG. 7 illustrates an axis 712 , which generally intersects an axis 710 at an origination point 720 (0,0). An intermediate BH curve 704 for the second iteration intersects a curve 711 at a tangent point 706 (i.e., iteration 2). Additionally, BH curve 704 intersects a curve 709 at an intersection point 702 (i.e., iteration 2). Note that graph 700 also illustrates a tangent point 708 for a third iteration for a curve 711 . Tangent point 708 is selected as a point on BH curve 711 close to point 702 . BH curve 709 also intersects axis 710 at point 714 (M zn , iteration 2).
FIG. 8 depicts a graph 800 illustrating a third iteration for a magnet element in a Z-direction, in accordance with a preferred embodiment of the present invention. Graph 800 generally depicts an axis 812 , which intersects with an axis 810 at an origination point 820 (0,0). An intermediate BH curve 804 for the third iteration intersects a curve 811 at a tangent point 806 (i.e., iteration 3). Additionally, BH curve 804 intersects a curve 809 at an intersection point 802 (i.e., iteration 3). Note that graph 800 also illustrates a tangent point 808 . Tangent point 808 is selected as a point on BH curve 811 close to point 802 . Point 808 is used to derive the final tangent line to be used as the BH curve for the nth magnet element if the desired accuracy has resulted in point 802 and 808 being sufficiently converged. If additional accuracy is needed, additional iterations can be executed. BH curve 809 additionally intersects axis 810 at a point 814 (M zn , iteration 3).
In FIGS. 1 to 4 , a method for modeling magnets with straight-line BH curves with permeability (μ) greater than one, in both the magnetized and non-magnetized directions is described with respect to modeling software. FIGS. 5 to 8 generally expand on that method by describing a method for modeling anisotropic magnets with non-linear BH curves in the magnetized and non-magnetized directions. Such a model can permit a designer to accurately model, for example, an anisotropic AlNiCo magnet utilized in a gear tooth sensor.
The magnet to be modeled generally can be configured with nonlinear BH curves, as illustrated in FIGS. 4 and 5 , and also described below with respect to Equation (32). Assume the magnet is magnetized in the z direction.
F x , F y , F z (32)
The x, y and z subscripts denote spatial direction. This denotation generally applies for all the equations indicated herein with respect to FIGS. 4 to 8 . The F variables are generally functions of H and B. For the modeling method described herein with respect to FIGS. 4 to 8 , such functions can be expressed generally in any form that is monotonic and increasing in B and H; linear or nonlinear; capable of being evaluated for B given H; capable of being evaluated for H given B; and which can be evaluated for the slope at any given point of the curve. Generally, H represents the magnetic field intensity (Oersted). B, on the other hand, generally represents the magnetic flux density (Gauss).
The magnet volume can be divided into volume elements. Each n th volume element itself is a magnet that can be modeled with the standard Narfmm software magnet model given the BH curve 404 and 502 such as illustrated in FIGS. 4 and 5 . The appropriate equations are indicated below in Equation (33).
B x =H x +M xn
B y =H y +M yn
B z =H z +M zn (33)
With respect to Equation (33) above, B generally represents the magnetic flux density (Gauss). H represents the magnetic field intensity (Oersted). M n represents the residual induction of the n th magnet element (Gauss).
The BH curves of Equations (32) and (33) intersect at the points (B xn ,H xn ), (B yn ,H yn ), (B zn ,H zn ). In this case, B n represents the magnetic flux density at the n th magnet element (Gauss), and H n represents the magnetic field intensity at the nth magnet element (Oersted). In order to model a magnet using modeling software (e.g., Narfmm), the variables M xn , M yn and M zn must be determined for each n th volume element. Each magnet element lies somewhere on the actual BH curve line indicated by Equation (32). The magnet element can be modeled with the “μ equal to one BH curve” indicated by Equation (33) if the proper M xn , M yn and M zn can be determined. If the intersection points (B xn ,H xn ), (B yn ,H yn ), (B zn ,H zn ) are known; M xn , M yn and M zn can be determined. Thus, the following formulation can be solved for Equation (34):
M xn =B xn −H xn
M yn =B yn −H yn
M zn =B zn −H zn (34)
Once all of the variables M xn , M yn and M zn are known, a standard magnet model can be utilized for each magnet element, summing all of the magnet elements' contributions through superposition to obtain the magnetic field from the whole magnet. The defining relation for the flux density inside a magnet can be calculated as follows.
B=μ·H+M+B e (35)
Thus, with respect to Equation (35) above, the variable B represents the magnetic flux density (Gauss). The variable μ represents the relative permeability, which is equal to one (Gauss/Oersted). Additionally, the variable H represents the magnetic field strength (Oersted). M represents the residual magnetic induction (Gauss). B e represents the magnetic flux density from sources external to the magnet (Gauss). For the n th magnet volume element, Equation (36) can be obtained utilizing Equation (35) and replacing μ with 1.
B xn =H xn +M xn +B xen
B yn =H yn +M yn +B yen
B zn =H zn +M zn +B zen (36)
With respect to Equation (35), the variables B en generally represent the magnetic flux densities on magnet element n from the other magnet elements (Gauss). Note that the center of the magnet volume element is used as the field point to determine the BH curve's intersection point in all equations. The larger the number of magnet elements, the smaller the element size, and the smaller the error associated with subdividing the magnet into a finite number of sections. Any arbitrary level of accuracy can be obtained by increasing the number of magnet elements to the proper level. H n can be expressed in normalized terms, as indicated below in Equation (37).
H xn =M xn ·H xNn
H yn =M yn ·H yNn
H zn =M zn ·H zNn (37)
H Nn represents the normalized H n in the indicated direction at the center of the n th magnet element (Oersted/Gauss). H Nn can be calculated with standard magnet modeling equations by letting the residual induction be equal to unity. B en can be expressed as a summation as indicated in Equation (38).
B
xen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
B
yen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
B
zen
=
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
(
38
)
In the right-hand side of Equation (38), the subscript on the B indicates the sub magnet orientation and the field direction. For example, “yx” refers to a field in x direction from the y facing magnet element. P represents the total number of magnet elements. B Nmn represents the normalized magnetic flux density from magnet element m to magnet element n in the magnetized direction (no units). B Nmn can be calculated with the standard magnet modeling equations by letting the residual magnetic induction of magnet element m be equal to unity. Thus, substituting Equation (37) and Equation (38) into Equation (36) yields Equation (39).
B
xn
=
M
xn
·
H
xNn
+
M
xn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
(
39
)
B
yn
=
M
yn
·
H
yNn
+
M
yn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
B
zn
=
M
zn
·
H
zNn
+
M
zn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
In order to determine the intersection point of the two BH curves illustrated in Equations (32) and (33), an iterative process is thus used. The first iteration involves assuming another form for the BH curve indicated by Equation (32), which is referred to as the intermediate BH curve given in Equation (40).
B x =α xn ·H x +b xn
B y =α yn ·H y +b yn
B z =α zn ·H z +b zn (40)
With respect to Equation (40), B represents the magnetic flux density (Gauss). The variable α n represents the slope of F at the tangent point explained below (Gauss/Oersted). The variable b n represents the B intercept of F for the n th magnet element (Gauss).
Refer to FIG. 6 for an illustration of the first iteration. The BH curve of equation (32) and (40) have a tangent point at the B intercept of F. Assuming equation (40) in place of (32), the intersection point is determined. From the intersection point, the tangent point for iteration 2 is selected by finding the point on F that has the same B value as the intersection point. In the second iteration, a new α n and b n is selected based on the tangent point as is illustrated in FIG. 7 . Then the second iteration intersection point is determined and the third iteration tangent point selected in the same manner as before. This process is then repeated as illustrated in FIG. 8 , which depicts the third iteration tangent point and intersection point, along with the fourth iteration tangent point. These three points now all lie very close together and can converge with each iteration. So it can be seen that the tangent point and intersection points converge onto the actual BH curve F. The iterations can be continued until the desired accuracy is obtained. This numerical iterative process converges very quickly and it is expected that approximately four iterations will be sufficient for most modeling applications. Note that in the first iteration all of the α n and b n (within a given direction X, Y or Z) will be the same since they all refer to the same starting function F. After the first iteration however they will in general not have the same value.
The equations to be used for each step of the iterative process are developed as further described below. Combining Equation (33) and (40) to determine the intersection point of the two BH curve lines, and solving for B n yields ( 41 ).
B xn = b xn - α xn · M xn ( 1 - α xn ) B yn = b yn - α yn · M yn ( 1 - α yn ) B zn = b zn - α zn · M zn ( 1 - α zn ) ( 41 )
Combining Equations (39) and (41) to eliminate B n yields Equation (42).
b
xn
-
α
xn
·
M
xn
(
1
-
α
xn
)
=
M
xn
·
H
xNn
+
M
xn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xxNmn
+
M
ym
·
B
yxNmn
+
M
zm
·
B
zxNmn
)
(
42
)
b
yn
-
α
yn
·
M
yn
(
1
-
α
yn
)
=
M
yn
·
H
yNn
+
M
yn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xyNmn
+
M
ym
·
B
yyNmn
+
M
zm
·
B
zyNmn
)
b
zn
-
α
zn
·
M
zn
(
1
-
α
zn
)
=
M
zn
·
H
zNn
+
M
zn
+
∑
m
=
1
m
≠
n
P
(
M
xm
·
B
xzNmn
+
M
ym
·
B
yzNmn
+
M
zm
·
B
zzNmn
)
In Equation (42) there are 3×P equations with 3×P unknowns since n takes on values from 1 to P. The 3×P unknowns are M xn , M yn and M zn . A linear set of equations is derived from Equation (42) that can be transformed into matrix form, as indicated in Equation (43).
Ψ×Φ=Γ (43)
Thus, with respect to Equation (43), the variable ψ represents a 3×P rows by 3×P columns matrix of known values. The variable φ represents a 3×P rows by 1 columns matrix, with elements M x 1 through M xp , M y1 through M yP and M z1 through M zP . The variable represen ts a 3×P rows by 1 column matrix of known values. To solve for the M xn , M yn and M zn , solve for φ.
Φ=Ψ −1 ×Γ (44)
The diagonal elements of ψ are as follows.
Ψ
kk
=
H
xNk
+
1
+
α
xk
1
-
α
xk
for
k
=
1
to
P
Ψ
kk
=
H
yN
(
k
-
P
)
+
1
+
α
yk
1
-
α
yk
for
k
=
P
+
1
to
2
·
P
Ψ
kk
=
H
zN
(
k
-
2
P
)
+
1
+
α
zk
1
-
α
zk
for
k
=
2
·
P
+
1
to
3
·
P
(
45
)
Each row of ψ, excluding the diagonals, is as follows.
Ψ kj =B xxNjk for k= 1 to P and j= 1 to P and k≠j
Ψ kj =B yxNj(k−P) for k=P+ 1 to 2· P and j= 1 to P and k≠j
Ψ kj =B zxNj(k−2 P) for k= 2· P+ 1 to 3· P and j= 1 to P and k≠j
Ψ kj =B xy(j−P)k for k= 1 to P and j=P+1 to 2· P and k≠j
Ψ kj =B yyN(j−P)(k−P) for k=P 1 to 2· P and j=P+ 1 to 2· P and k≠j
Ψ kj =B zyN(j−P)(k−2 P) for k= 2· P+ 1 to 3· P and j=P+ 1 to 2· P and k≠j
Ψ kj =B xzN(j−2 P) for k= 1 to P and j= 2· P 1 to 3· P and k≠j
Ψ kj =B yzN(j−2 P) for k=P 1 to 2· P and j= 2· P+ 1 to 3· P and k≠j
Ψ kj =B zzN(j−2 P)(k−2 P) for k= 2· P+ 1 to 3 ·P and j= 2· P+ 1 to 3· P and k≠j (46)
In Equations (45) and (56), the subscript index on ψ indicates the row and column number of the matrix element respectively. Each element of is as follows:
Γ
k
=
b
xk
1
-
α
xk
for
k
=
1
to
P
Γ
k
=
b
y
(
k
-
P
)
1
-
α
y
(
k
-
P
)
for
k
=
P
+
1
to
2
·
P
Γ
k
=
b
z
(
k
-
2
P
)
1
-
α
z
(
k
-
2
P
)
for
k
=
2
·
P
+
1
to
3
·
P
(
47
)
Those skilled in the art can appreciate that the present invention can be implemented in the context of a module or group of modules. The term “module” as known by those skilled in the computer programming arts is generally a collection of routines, subroutines, and/or data structures, which perform a particular task or implements certain abstract data types. Modules generally are composed of two sections. The first section is an interface, which compiles the constants, data types, variables, and routines. The second section is generally configured to be accessible only by the module and which includes the source code that activates the routines in the module or modules thereof.
A software implementation of the present invention may thus involve the use of such modules, and/or implementation of a program product based on the mathematical and operational steps illustrated in and described herein. Such a program product may additionally be configured as signal-bearing media, including recordable and/or transmission media. The mathematical and operation steps illustrated and described herein can thus be implemented as program code, a software module or series of related software modules. Such modules may be integrated with hardware to perform particular operational functions.
FIG. 9 illustrates a pictorial representation of a data processing system 910 , which may be utilized in accordance with the method and system of the present invention. The method and system described herein, including module implementations thereof, may be implemented in a data processing system such as data processing system 910 of FIG. 9 . Thus, data processing system 910 is illustrated herein to indicate a possible machine in which the present invention may be embodied. Those skilled in the art can appreciate, however, that the data processing system illustrated in FIGS. 9 and 10 herein is presented for illustrative purposes only and is not considered a limiting feature of the present invention.
Data processing system 910 can be implemented as a computer, which includes a system unit 912 , a video display terminal 914 , an alphanumeric input device (i.e., keyboard 916 ) having alphanumeric and other keys, and a mouse 918 . An additional input device (not shown) such as a trackball or stylus can also be included with data processing system 910 . Although the depicted embodiment involves a personal computer, an embodiment of the present invention may be implemented in other types of data processing systems, such as, for example, intelligent workstations or mini-computers. Data processing system 910 also preferably includes a graphical user interface that resides within a machine-readable media to direct the operation of data processing system 910 .
Referring now to FIG. 10 there is depicted a block diagram of selected components in data processing system 910 of FIG. 9 in which a preferred embodiment of the present invention may be implemented. Data processing system 910 of FIG. 9 preferably includes a system BUS 920 , as depicted in FIG. 10 . System BUS 920 is utilized for interconnecting and establishing communication between various components in data processing system 910 . Microprocessor or CPU (Central Processing Unit) 922 is connected to system BUS 920 and also may have numeric coprocessor 924 connected to it. Direct memory access (“DMA”) controller 926 is also connected to system BUS 920 and allows various devices to appropriate cycles from microprocessor 922 during large input/output (“I/O”) transfers. Read Only Memory (“ROM”) 928 and Random Access Memory (“RAM”) 930 are also connected to system BUS 920 . ROM 928 can be mapped into the address space of microprocessor 922 . CMOS RAM 932 is generally attached to system BUS 920 and contains system configuration information. Any suitable machine-readable media may retain the graphical user interface of data processing system 910 of FIG. 9 , such as RAM 930 , ROM 928 , a magnetic diskette, magnetic tape, or optical disk.
Also connected to system BUS 920 are memory controller 934 , BUS controller 936 , and interrupt controller 938 , which serve to aid in the control of data flow through system BUS 920 among various peripherals, adapters, and devices. System unit 912 of FIG. 9 also contains various I/O controllers such as those depicted in FIG. 10 : keyboard and mouse controller 940 , video controller 942 , parallel controller 944 , serial controller 946 , and diskette controller 948 . Keyboard and mouse controller 940 provide a hardware interface for keyboard 950 and mouse 952 although other input devices can be used. Video controller 942 provides a hardware interface for video display terminal 954 . Parallel controller 944 provides a hardware interface for devices such as printer 956 . Serial controller 946 provides a hardware interface for devices such as a modem 958 . Diskette controller 948 provides a hardware interface for floppy disk unit 960 .
Expansion cards also may be added to system bus 920 , such as disk controller 962 , which provides a hardware interface for hard disk unit 964 . Empty slots 966 are provided so that other peripherals, adapters, and devices may be added to system unit 912 of FIG. 9 . A network card 967 additionally can be connected to system bus 920 in order to link system unit 912 of FIG. 9 to other data processing system networks in a client/server architecture, or to groups of computers and associated devices which are connected by communications facilities. Those skilled in the art will appreciate that the hardware depicted in FIG. 10 may vary for specific applications. For example, other peripheral devices such as: optical disk media, audio adapters, or chip programming devices such as a PAL or EPROM programming devices, and the like also may be utilized in addition to or in place of the hardware already depicted. Note that any or all of the above components and associated hardware may be utilized in various embodiments. It can be appreciated, however, that any configuration of the aforementioned system may be utilized for various purposes according to a particular implementation. FIGS. 9-10 therefore generally describe a system/apparatus 910 composed of one or more processor readable storage devices having a processor readable code (e.g., a module) embodied on the processor readable storage devices. The processor readable storage devices can be then used for programming one or more processors to perform the methodology described herein, including each of the method steps of such a methodology.
The present invention can be used in various magnetic modeling scenarios. For example, the present invention can be use to design sensors that contain permanent magnets. Such sensors include gear tooth sensors.
The embodiments and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered. The description as set forth is not intended to be exhaustive nor to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the spirit and scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects.
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Methods and systems for magnetostatic modeling of a magnetic object is disclosed. A varying surface charge density is established at a surface of a magnetic object modeled by a magnetostatic model. Thereafter, a varying magnetic charge is generally distributed throughout a volume of the magnetic object to thereby accurately and efficiently model the magnetic object across a wide range of magnetic curves utilizing the magnetostatic model. The magnetic curves can be configured to generally comprise at least one non-linear magnetic curve and/or least one linear magnetic curve. Such magnetic curves may also comprise at least one magnetic curve in a magnetized direction and/or non-magnetized direction. Such magnetic curves are generally referred to as “BH curves”.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally in the field of fabrication of structures in semiconductor chips. In particular, the invention is in the field of fabrication of structures using low dielectric constant (“low-k”) material.
2. Background Art
It is known in the art that a dielectric material used in the fabrication of integrated circuit structures should have a low dielectric constant (“low-k”). The advantages of using low dielectric constant material in such structures are well-known. One of the advantages is a reduction in the inter-line coupling capacitance between metal lines. Such capacitance causes “noise” or “crosstalk” between metal lines. Another advantage is the reduction of capacitance between different layers of interconnect and also a reduction of capacitance between a layer of interconnect to the substrate. It is known in the art that a lower capacitance will reduce the interconnect metal line delay, i.e. the “RC” delay. Another advantage is the significant decrease in power consumption resulting from the lower capacitance since the amount of power consumed is directly proportional to the capacitance. Thus, it is generally appreciated in the art that the use of low dielectric constant material in the fabrication of integrated circuit structures is desirable for the reasons mentioned above.
Silicon dioxide is one of the dielectric materials used in the fabrication of integrated circuit structures because of its desirable features such as adequate hardness, and ease of cleaning and etching for even small feature sizes. However, the dielectric constant value of silicon dioxide is about 4.0. It is generally appreciated in the art that this dielectric constant value is too high. Thus, there is a drive to utilize materials with lower dielectric constant values in the fabrication of integrated circuit structures.
Polymers with a dielectric constant value of 2.5 or 3.0 are achievable. One method of reducing the dielectric constant of some polymer films is to increase the porosity of the polymer by introducing air into the pores of the polymer. Since the dielectric constant value of air is 1.0, introducing air into the material decreases the dielectric constant value of the material.
However, there are also problems associated with the use of lower dielectric constant material in the fabrication of integrated circuit structures. For example, etching low-k dielectric is difficult. Most low-k dielectrics are easily damaged by the etch chemistry or plasma. As an example, hydrogen silsesquioxane (also referred to as “HSQ”) is a low-k dielectric which has been used in the fabrication of integrated circuits. However, the silicon-hydrogen bond in hydrogen silsesquioxane is weak and can easily be broken. Once the silicon-hydrogen bond is broken, the remaining material exhibits a tendency to absorb moisture. Also, during etching of most low-k dielectrics, polymers are generated which are hard to clean without etching away the low-k dielectric itself.
In addition, most low-k dielectrics have poor mechanical strength. One reason poor mechanical strength is undesirable is because low-k dielectric may not withstand chemical mechanical polishing (“CMP”). It is known in the art that the CMP process is usually used to remove excess metal over the wafer surface after the metal has been used to create damascene structures.
Thus, problems associated with the use of a low-k dielectric material in the fabrication of integrated circuit structures include (a) difficulty in etching and cleaning low-k dielectric materials; (b) undesirable absorption of moisture; and (c) low mechanical strength of low-k dielectric materials.
It is known that when dielectric material is exposed to electron beams (E-beams) or ion beams (I-beams), the properties of the dielectric material can be changed. For example, a paper entitled “E-Beam Curing Process of Low-K Dielectrics for unlanded vias in 0.25 μm CMOS Technology” by David Feiler, Q. Z. Liu, and Maureen R. Brongo discusses an E-beam curing process of low-k dielectrics for unlanded vias in a CMOS technology. It is shown in that paper that the properties of the low-k dielectric can be modified so as to prevent unlanded vias from penetrating too deeply into the underlying low-k dielectric.
A second paper entitled “A Novel and Low Thermal Budget Planarization Scheme for Pre- and Inter-Metal Dielectric Using HSQ (Hydrogen Silsesquioxane) Based SOG with Electron-Beam Curing for 256 Mbit DRAM and Beyond” by Juseon Goo, Hae-Jeong Lee, Seong Ho Kim, Ji Hyun Choi, Byung Keun Hwang, Ho-Kyu Kang, and Moon Yong Lee discusses a finding that hydrogen silsesquioxane can be cured and densified with exposure to E-beams.
A third paper entitled “Integration of Low k Spin-on Polymer (SOP) Using Electron Beam Cure for Non-Etch-Back Application” by Jane C. M. Hui, Yi Xu, Chow Yeog Foong, Liao Marvin, Lin Charles, and Lin Yih Shung discusses an E-beam curing process for spin-on glass materials in relation to spin-on polymer non-etch-back processing such as “via poisoning.” It is shown that after E-beam exposure, the tested materials' properties had changed, e.g. lower moisture content, higher film density and higher resistance were achieved.
A fourth paper entitled “Effects of Electron Beam Exposure on Poly(arylene Ether) Dielectric Films” by J. S. Drage, J. J. Yang, D. K. Choi, R. Katsanes, K. S. Y. Lau, S.-Q. Wang, L. Forester, P. E. Schilling, and M. Ross discusses the effects of E-beam exposure on chemical and physical properties of an organic dielectric film. Specifically, solvent resistance, glass transition temperature, and dielectric constant of the film are studied. The results of the study indicate that E-beam curing does not raise the dielectric constant compared to thermally-cured film.
In addition to the above-discussed papers, there are patents utilizing methods that alter the physical properties of dielectric materials using ion implantation. One such patent is U.S. Pat. No. 5,496,776 entitled “Spin-On Glass Planarization Process With Ion Implantation.” This patent discloses a method for planarizing an integrated circuit surface with a spin-on-glass sandwich layer, where the entire surface area of spin-on-glass exposed within a via etched through the spin-on-glass sandwich layer is not susceptible to sorption and outgassing of moisture. The patent also teaches a method of planarizing an integrated circuit surface which does not result in metallurgy and high resistivity problems associated with metallic interconnections through vias etched through the planarizing layer. One step in these methods is the implantation of ions into and through a spin-on-glass layer under various conditions. This method eliminates the need for an etch back process for the spin-on-glass exposed within the etched vias prior to metal deposition into those etched vias.
U.S. Pat. No. 5,192,697 entitled “SOG Curing By Ion Implantation” discloses among other things, a method of curing the spin-on-glass layer of an article which results in similar or better dielectric strength than a temperature cure method. Ions, such as argon or arsenic are implanted into the spin-on-glass layer of an article. The action of the ions moving through the spin-on-glass layer causes heating. This heating cures the spin-on-glass layer of the article.
U.S. Pat. No. 5,413,953 entitled “Method Of Planarizing An Insulator On A Semiconductor Substrate Using Ion Implantation” discloses an improved process for fabricating planar field oxide structures on a silicon substrate. The patent also discloses an improved process for fabricating planar Field Oxide (FOX) isolation structures and an improved process for fabricating planar insulating layers over patterned conducting layers by ion implantation and etching.
As part of these processes, the substrate surface is implanted with arsenic or phosphorus ions. This ion implantation results in a damaged oxide layer, which etches approximately 2 to 4 times faster than the undamaged portion of the field oxide. As a result of faster etching of the damaged portion of the field oxide, the desired structures can be more easily fabricated.
Although it is desirable to use low-k dielectrics for the reasons stated above, the use of low-k dielectrics is accompanied by various problems also discussed above. The above-discussed papers and patents have not overcome a number of problems associated with the use of low-k dielectrics. Accordingly, there is a need in the art for using low-k dielectric materials in the fabrication of integrated circuit structures while overcoming the various problems resulting from the use of low-k dielectric materials. For example, there is need to use low-k dielectric material in the recently developed damascene fabrication processes while overcoming the various problems resulting from the use of such material.
SUMMARY OF THE INVENTION
The present invention teaches fabrication of improved low-k dielectric structures. According to the present invention, low-k dielectric structures are fabricated while overcoming the otherwise existing problems associated with the use of low-k dielectric materials. The invention resolves the difficulties in etching and cleaning low-k dielectric materials, the undesirable absorption of moisture by low-k dielectric materials, and the low mechanical strength of low-k dielectric materials.
In one embodiment of the invention, the physical properties of a low-k dielectric material is modified by exposing the low-k dielectric material to electron beams. The exposed portion of the low-k dielectric material becomes easier to etch and clean and exhibits greater mechanical strength and a reduction in absorption of moisture. In another embodiment of the invention, a number of incremental exposure and etch steps are performed to fabricate a desired structure.
In yet another embodiment of the invention, the steps of exposure of a low-k dielectric material are combined with the etch steps. The exposure and the etching of the low-k dielectric material are performed concurrently in the same system. In still another embodiment, the invention utilizes a single exposure and a single etch step to fabricate a desired structure. All embodiments of the invention can be practiced by exposing the low-k dielectric material to ion beams instead of electron beams.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an initial low-k dielectric structure including a photoresist pattern.
FIG. 2 illustrates an incremental exposure step where the low-k dielectric is exposed to electron beams.
FIG. 3 illustrates an incremental etch step where the modified low-k dielectric is etched.
FIG. 4 illustrates an incremental exposure step where the low-k dielectric is exposed to electron beams.
FIG. 5 illustrates an incremental etch step where the modified low-k dielectric is etched.
FIG. 6 illustrates an incremental exposure step where the low-k dielectric is exposed to electron beams.
FIG. 7 illustrates an incremental etch step where the modified low-k dielectric is etched.
FIG. 8 illustrates an incremental exposure step where the low-k dielectric is exposed to electron beams.
FIG. 9 illustrates an incremental etch step where the modified low-k dielectric is etched.
FIG. 10 shows the structure achieved after the last incremental etch step and after stripping of the photoresist from the low-k dielectric.
FIG. 11 shows the final structure including the metal filling the etched portion of the low-k dielectric.
FIG. 12 shows an initial low-k dielectric structure including a photoresist pattern.
FIG. 13 illustrates a single exposure step where the low-k dielectric is exposed to electron beams.
FIG. 14 illustrates a single etch step where the modified low-k dielectric is etched.
FIG. 15 shows the structure achieved after the last single etch step and after stripping of the photoresist from the low-k dielectric.
FIG. 16 shows the final structure including metal filling the etched portion of the low-k dielectric.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to fabrication of improved low-k dielectric structures. The following description contains specific information pertaining to the implementation of the present invention. One skilled in the art will recognize that the present invention may be implemented in a manner different from that specifically discussed in the present application. Moreover, some of the specific details of the invention are not discussed in order to not obscure the invention. The specific details not described in the present application are within the knowledge of a person of ordinary skill in the art.
The drawings in the present application and their accompanying detailed description are directed to merely example embodiments of the invention. To maintain brevity, other embodiments of the invention which use the principles of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings.
In the present application, the invention is explained by reference to a damascene process. The term “damascene” is derived from the ancient in-laid metal artistry originated in Damascus. According to the damascene process, trenches are cut into the dielectric and then filled with metal. Then excess metal over the wafer surface is removed to form desired interconnect metal patterns within the trenches.
It is noted that although the present application discloses a method for fabricating interconnects in a damascene process using a dielectric with a low dielectric constant, the invention is also applicable to fabricating interconnects using a dielectric with a low dielectric constant in semiconductor processes other than the damascene process.
The present invention maintains the advantages of the low dielectric constant material such as lower inter-line coupling capacitance, lower inter-layer coupling capacitance, lower “RC” delay, and lower power due to lower capacitance. At the same time the disadvantages of the low dielectric constant material affecting the fabrication of integrated circuit structures, such as its low mechanical strength and the vulnerability of low-k dielectric to the etch chemistry are overcome by the method and structure disclosed in the present invention. Thus, the present invention makes low dielectric constant material easier to etch and to clean.
One embodiment of the invention is shown in FIGS. 1 through 11, which illustrate various process steps in the present embodiment of the invention by showing the cross sections of the resulting structures after each process step.
As the present embodiment of the invention's first step in fabricating damascene interconnects using a dielectric with a low dielectric constant, FIG. 1 shows photoresist 12 patterned on top of low-k dielectric 14 . Photoresist 12 is used to pattern a desired structure in low-k dielectric 14 . In the present embodiment of the invention, low-k dielectric 14 can be hydrogen silsesquioxane (HSQ). FIG. 2 shows the application of electron beams (E-beams) 18 to low-k dielectric 14 . By use of E-beams 18 , physical properties of low-k dielectric 14 are modified. E-beams 18 break the bond between the silicon and hydrogen in hydrogen silsesquioxane, allowing the hydrogen to “escape”. The material that remains after exposure to E-beams 18 is referred to as “modified low-k dielectric” or simply as “modified dielectric material” in the present application. The portion of the initial low-k dielectric 14 that is not affected by E-beams 18 is referred to as an “unmodified low-k dielectric” or simply as “unmodified dielectric material” in the present application. As will be explained in a later section of this application, modified low-k dielectric 16 which remains after application of E-beams 18 is substantially easier to etch and to clean than the initial low-k dielectric 14 . This ease of etching and cleaning results from the fact that the initial low-k dielectric 14 becomes harder after exposure to E-beams 18 .
At the outset, it is noted that it is desirable to achieve the modified low-k material using the invention's method in a direction perpendicular to E-beams 18 incident on low-k dielectric 14 . However, as a result of the invention's method, the low-k dielectric 14 under the photoresist is modified laterally to a certain extent. This phenomenon is referred to as “lateral encroachment” in the present application. It is desirable to limit lateral encroachment of modified low-k dielectric 16 into low-k dielectric 14 because modified low-k dielectric 16 has a higher dielectric constant than low-k dielectric 14 . As discussed above, the higher dielectric constant of the modified low-k dielectric 16 increases the intra-line capacitance. As also discussed above, this results in undesirable “noise” between lines, an increased “RC” delay, and higher power consumption.
In a manner explained below, the present embodiment limits lateral encroachment. In the present embodiment E-beams 18 are used to modify low-k dielectric 14 in a number of incremental exposure steps where each incremental exposure step is followed by a corresponding incremental etch step. FIGS. 2 through 9 illustrate the above-mentioned incremental exposure and etch steps that are taken in order to modify low-k dielectric 14 to arrive at the final structure of the invention. The exemplary number of incremental exposure steps discussed to explain the present embodiment of the invention is four. Likewise, the corresponding number of incremental etch steps discussed to explain the present embodiment is also four. It is appreciated by a person of ordinary skill in the art that the number of incremental exposure and etch steps can be varied without departing from the spirit and scope of the present embodiment of the invention. For example, the number of incremental exposure and etch steps can be eight or greater.
As stated above, after the first of four incremental exposure steps, low-k dielectric 14 is modified and becomes modified low-k dielectric 16 to a certain depth. The lateral encroachment can be about one-half the depth of modified low-k dielectric 16 for this incremental exposure step. The present embodiment of the invention limits the lateral encroachment of modified low-k dielectric 16 into low-k dielectric 14 resulting from an E-beam incremental exposure step.
The present embodiment of the invention uses low-power E-beams 18 . Lower power E-beams are used to modify low-k dielectric 14 in a number of incremental exposure steps. The lower power E-beams permit this embodiment of the invention to modify low-k dielectric 14 in small incremental steps since, due to their relatively low power, the E-beams do not penetrate as deeply as they otherwise would.
Referring to FIG. 2, a specific example of the present embodiment of the invention is now discussed. FIG. 2 illustrates the first of four incremental exposure steps in the present exemplary embodiment. During this step low-k dielectric 14 is exposed to a small amount of E-beams 18 generated by a low power E-beam source. The area of low-k dielectric 14 which is exposed to E-beams 18 is also referred to as a “target area” in the present application. The E-beam source is not shown in any of the Figures. However, commercial E-beam sources are readily available and in fact one advantage of utilizing an E-beam source in the present embodiment is that, because of their wide availability, E-beam sources are relatively inexpensive. Due to exposure to E-beams 18 , low-k dielectric 14 is modified down to a certain depth. This depth achieved as a result of the first incremental exposure step is generally referred to in FIG. 2 by numeral 19 . Thus, depth 19 is the depth of modified low-k dielectric 16 achieved at the end the first exposure step.
As discussed above, as a by-product of the incremental exposure step, modified low-k dielectric 16 can encroach laterally under photoresist 12 . The amount of lateral encroachment of modified low-k dielectric 16 is generally pointed to by numeral 17 in FIG. 2 and the modified low-k dielectric which is extended under photoresist 12 is referred to as the laterally modified low-k in the present application.
In the present example, after the first of four incremental exposure steps, depth 19 of modified low-k dielectric 16 is about 0.1 microns. In this example, lateral encroachment 17 of modified low-k dielectric 16 under photoresist 12 would be about one-half of the 0.1 microns depth, i.e., about 0.05 microns.
Referring to FIG. 3, the first of four incremental etch steps is then performed on the structure achieved at the end of the first incremental exposure step. The result of this incremental etch step is shown in FIG. 3 . The first incremental etch step removes most of modified low-k dielectric 16 in the vertical direction, but does not remove a significant amount of the laterally modified low-k dielectric 16 which has encroached under photoresist 12 (the amount of such lateral encroachment was referred to by numeral 17 in FIG. 2 ). The etchant used in this first incremental etch step as well as the remaining incremental etch steps in the present embodiment is a fluorine based plasma, for example, CF 4 or CH 2 F 2 . The portion of modified low-k dielectric 16 which is removed during an incremental etch step is referred to as an “etched portion” in the present application.
Referring to FIG. 4, a second incremental exposure step is performed. As shown in FIG. 4, after the second of four incremental exposure steps, depth 19 of modified low-k dielectric 16 increases to about 0.2 microns, i.e., depth 19 has increased by another 0.1 microns. However, as shown in FIG. 4, lateral encroachment 17 has remained constant at about 0.05 microns.
Referring to FIG. 5, the second of four incremental etch steps is then performed on the structure achieved at the end of the second incremental exposure step. The result of this incremental etch step is shown in FIG. 5 . The second incremental etch step removes most of modified low-k dielectric 16 in the vertical direction, but does not remove a significant amount of the laterally modified low-k dielectric 16 which has encroached under photoresist 12 (the amount of such lateral encroachment was referred to by numeral 17 in FIGS. 2 and 4 ).
Referring to FIG. 6, after the third of four incremental exposure steps, depth 19 of modified low-k dielectric 16 is about 0.3 microns, i.e., depth 19 has increased by another 0.1 microns. However, lateral encroachment 17 has still remained constant at about 0.05 microns.
Referring to FIG. 7, the third of four incremental etch steps is then performed on the structure achieved at the end of the third incremental exposure step. The result of this incremental etch step is shown in FIG. 7 . As with the previous incremental etch steps, the third incremental etch step removes most of modified low-k dielectric 16 in the vertical direction, but does not remove a significant amount of the laterally modified low-k dielectric 16 which has encroached under photoresist 12 (the amount of such lateral encroachment was referred to by numeral 17 in FIGS. 2, 4 , and 6 ).
FIG. 8 shows the last incremental exposure step in the present example implementation of the present embodiment of the invention. Referring to FIG. 8, after the last of four incremental exposure steps, depth 19 of modified low-k dielectric 16 is about 0.4 microns, i.e., depth 19 has increased by another 0.1 microns. However, lateral encroachment 17 has remained constant at about 0.05 microns.
Referring to FIG. 9, the fourth (and the final) incremental etch step in this example implementation of the present embodiment of the invention is then performed on the structure achieved at the end of the fourth incremental exposure step. The result of this incremental etch step is shown in FIG. 9 . As with previous incremental etch steps, the fourth incremental etch step removes most of modified low-k dielectric 16 in the vertical direction, but does not remove a significant amount of the laterally modified low-k dielectric 16 which has encroached under photoresist 12 (the amount of such lateral encroachment was referred to by numeral 17 in FIGS. 2, 4 , 6 , and 8 ). As with the previous incremental etch steps, the etchant used in this final incremental etch step is a fluorine based plasma, for example, CF 4 or CH 2 F 2 . FIG. 9 shows that after the last step of the process described above, the ultimate target depth 19 is achieved.
Referring to FIG. 10, the next step in the present embodiment of the invention is described. In this step, photoresist 12 is stripped using a conventional oxygen plasma or hydrogen plasma or forming gas (H 2 /N 2 ) in a manner well known in the art.
Referring to FIG. 11, the next and last step in the present embodiment of the invention is described. In this step the etched portion of modified low-k dielectric 16 is filled with metal 20 in a manner well known in the art. Metal 20 can be copper, aluminum, or another metal. After filling the etched portion of modified low-k dielectric 16 with metal, a chemical mechanical polish (“CMP”) is performed to remove the excess metal from the surface of the low-k dielectric. As stated above, modified low-k dielectric 16 exhibits good mechanical strength and results in proper completion of the CMP process.
In the present application, the side or surface of modified low-k dielectric 16 which interfaces metal 20 is referred to as a “first surface” of modified low-k dielectric 16 while the side or surface of modified low-k dielectric 16 which interfaces unmodified low-k dielectric 14 is referred to as a “second surface” of modified low-k dielectric 16 .
In another implementation of the present embodiment of the invention the step of exposure of low-k dielectric 14 to E-beams 18 could be “combined” with the etch step. The exposure and the etching could be performed with the same tool in the same system. Performing the exposure and the etching with the same tool in the same system means that the number of incremental exposure and etch steps can be increased as much as desired. The system would perform very fine incremental exposure and etch steps. In this way lateral encroachment 17 of modified low-k dielectric 16 into low-k dielectric 14 could be minimized even further.
Thus it is seen that the present embodiment of the invention maintains the advantages of the low dielectric constant material, including lower intra-line coupling capacitance, lower intra-layer coupling capacitance, lower “RC” delay, and lower power consumption due to the lower capacitance. At the same time, the low dielectric constant material becomes easier to etch and to clean. Moreover, the method and structure disclosed in the present embodiment of the invention improves the mechanical strength of the low-k dielectric material and also overcomes the vulnerability of the low-k dielectric material to various etchants.
Another embodiment of the invention is shown in FIGS. 12 through 16, which illustrate various process steps in the present embodiment of the invention by showing the cross sections of the resulting structures after each process step.
According to this embodiment of the invention, the process of modifying a low-k dielectric material can be performed in a single exposure step and a single etch step instead of a number of incremental steps. As the present embodiment of the invention's first step in fabricating damascene interconnects using a dielectric with a low dielectric constant, FIG. 12 shows photoresist 22 patterned on top of low-k dielectric 24 . Photoresist 22 is used to pattern a desired structure in low-k dielectric 24 . As with the previous embodiment described above, in the present embodiment of the invention, low-k dielectric 24 can be hydrogen silsesquioxane (HSQ). FIG. 13 shows the application of electron beams (E-beams) 28 to low-k dielectric 24 . By use of E-beams 28 , physical properties of low-k dielectric 24 are modified. E-beams 28 break the bond between the silicon and hydrogen in hydrogen silsesquioxane, allowing the hydrogen to “escape”. The material that remains after exposure to E-beams 28 is referred to as “modified low-k dielectric”, and is generally referred to in FIG. 13 by the numeral 26 . As explained above, modified low-k dielectric 26 , which remains after application of E-beams 28 is substantially easier to etch and to clean than the initial low-k dielectric 24 .
The present embodiment of the invention uses high energy E-beams 28 . High energy E-beams are used to modify low-k dielectric 24 in one exposure step. The high energy E-beams permit this embodiment of the invention to modify low-k dielectric 24 in one step since, due to their relatively higher energy, the E-beams penetrate deep into low-k dielectric 24 .
Referring to FIG. 13, a specific example of the present embodiment of the invention is now discussed. FIG. 13 illustrates the single exposure step in the present exemplary embodiment. During this step low-k dielectric 24 is exposed to E-beams 28 generated by a high-energy E-beam source. The E-beam source is not shown in any of the Figures. However, commercial E-beam sources are readily available and in fact one advantage of utilizing an E-beam source in the present embodiment is that, because of their wide availability, E-beam sources are relatively inexpensive. Due to exposure to E-beams 28 , low-k dielectric 24 is modified down to a certain depth. This depth achieved as a result of the exposure step is generally referred to in FIG. 13 by numeral 29 . Thus, depth 29 is the depth of modified low-k dielectric 26 achieved after the single exposure step of the present embodiment.
As discussed above, as a by-product of the exposure step, modified low-k dielectric 26 can encroach laterally under photoresist 22 . The amount of lateral encroachment of modified low-k dielectric 26 is generally pointed to by numeral 27 in FIG. 13 and the modified low-k dielectric which is extended under photoresist 22 is referred to as the laterally modified low-k in the present application.
In the present exemplary embodiment depth 29 of modified low-k dielectric 26 is about 0.4 microns after the single exposure step. Lateral encroachment 27 of modified low-k dielectric 26 under photoresist 22 would be about one-half of the 0.4 microns depth, i.e., about 0.2 microns.
Referring to FIG. 14, the etch step is then performed on the structure achieved at the end of the exposure step. The result of this etch step is shown in FIG. 14 . The first incremental etch step removes most of modified low-k dielectric 26 in the vertical direction, but does not remove a significant amount of the laterally modified low-k dielectric 26 which has encroached under photoresist 22 (the amount of such lateral encroachment was referred to by numeral 27 in FIG. 13 ). The etchant used in this etch step in the present embodiment is a fluorine based plasma, for example, CF 4 or CH 2 F 2 .
Referring to FIG. 15, the next step in the present embodiment of the invention is described. In this step, photoresist 22 is stripped using a conventional oxygen plasma or hydrogen plasma or forming gas (H 2 /N 2 ) in a manner well known in the art.
Referring to FIG. 16, the next and last step in the present embodiment of the invention is described. In this step the etched portion of modified low-k dielectric 26 is filled with metal 30 in a manner well known in the art. Metal 30 can be copper, aluminum, or another metal. After filling the etched portion of modified low-k dielectric 26 with metal, a chemical mechanical polish (“CMP”) is performed to remove the excess metal from the surface of the low-k dielectric. As stated above, modified low-k dielectric 26 exhibits good mechanical strength and results in proper completion of the CMP process.
Thus, it is seen that according to this embodiment of the invention, the process of modifying a low-k dielectric material is performed in a single exposure step and a single etch step.
As explained above, the present invention discloses a method for using dielectrics with a low dielectric constant in semiconductor chips while overcoming the disadvantages associated with the use of such dielectrics. The advantages of using low-k dielectric material in the fabrication of integrated circuit structures, such as lower inter-line capacitance, lower inter-layer coupling capacitance, lower “RC” delay, and lower power consumption due to lower capacitance, are maintained. At the same time the disadvantages of using low-k dielectric material in the fabrication of integrated circuit structures, such as the difficulty in etching and cleaning of the low-k dielectric material, and the difficulty in performing the CMP process due to the low mechanical strength of low-k dielectric material are overcome by the method disclosed in the present invention.
From the above description of the invention it is manifest that various techniques can be used for implementing the concepts of the present invention without departing from its scope. For example, the E-beam source can be replaced with an Ion Beam (“I-Beam”) source. In that case, I-Beams, instead of E-beams could be used to implement the present invention. Also, various low-k dielectrics other than HSQ, which was used merely as an example in the present application, can be used. Furthermore, the various dimensions and sizes specifically mentioned in the present application can be varied without departing from the scope of the present invention.
Thus, while the invention has been described with specific reference to certain embodiments, a person of ordinary skill in the art would recognize that changes can be made in form and detail without departing from the spirit and the scope of the invention. The described embodiments are to be considered in all respects as illustrative and not restrictive. It should also be understood that the invention is not limited to the particular embodiments described herein, but is capable of many rearrangements, modifications, and substitutions without departing from the scope of the invention.
Thus, fabrication of improved low-k dielectric structures has been described.
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Fabrication of improved low-k dielectric structures is disclosed. Low-k dielectric structures are fabricated while overcoming the otherwise existing problems associated with the use of low-k dielectric materials. In one embodiment, the physical properties of a low-k dielectric material is modified by exposing the low-k dielectric material to electron beams. The exposed portion of the low-k dielectric material becomes easier to etch and clean and exhibits greater mechanical strength and a reduction in absorption of moisture. In another embodiment, a number of incremental exposure and etch steps are performed to fabricate a desired structure. In yet another embodiment, the steps of exposure of a low-k dielectric material are combined with the etch steps. The exposure and the etching of the low-k dielectric material are performed concurrently in the same system. In still another embodiment, a single exposure and a single etch step are utilized to fabricate a desired structure. All the disclosed embodiments can be practiced by exposing the low-k dielectric material to ion beams instead of electron beams.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 235,243, filed Feb. 17, 1982, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a semi-continuous process for making elastomeric star-block copolymers.
Highly branched block copolymers, sometimes called star-block copolymers, are old in the art of anionic polymerization. These star-block copolymers are prepared by first forming linear block polymer having active lithium atom on one end of the polymer chain. These active, linear polymer chains are then coupled by the addition of a polyfunctional compound having at least three reactive sites capable of reacting with the carbon to lithium bond on the polymer chains to add the polymer chain onto the functional groups of the compound.
Zelinski, U.S. Pat. No. 3,280,084, polymerized butadiene with butyllithium initiator to form B-Li blocks (where B is polybutadiene) which when coupled with 0.02 to 1 part by weight per 100 parts of monomers of divinylbenzene gave starblock copolymers having polydivinylbenzene nuclei and several identical arms of polybutadiene branching therefrom. The arms can also be either random or block copolymers of styrene and butadiene (from A-B-Li blocks, where A is polystyrene segment) where the diene is the major component.
Zelinski, U.S. Pat. No. 3,281,383, teaches similar starblock copolymers to those in U.S. Pat. No. 3,280,084, except that coupling agents such as polyepoxy compounds, polyacids, polyaldehydes, etc., are used.
Childers, U.S. Pat. No. 3,637,554, prepares rubbery starblock copolymers having nuclei formed from polyepoxides, polyisocyanates, polyimines, etc., and idential arms from B-Li and A-B-Li.
Fetters et al., U.s. Pat. No. 3,985,830, discloses a product having a nucleus of more than one molecule of m-divinylbenzene and at least three polymeric arms, each being a block copolymer of conjugated diene and monovinyl aromatic monomers wherein said conjugated diene block is linked to said nucleus.
The above patents all suffer from the disadvantage of being lengthy batch processes which require cleaning out of the batch reactor after each run.
SUMMARY OF THE INVENTION
We have now found that the length of each run needed to prepare the star-block copolymers can be shortened considerably and the need to clean out the reactor eliminated by going to a semi-continuous process.
The process involves four separate reactors arranged such that rapid transfer of the contents of each reactor to another reactor is possible. Each reactor is used only for a specific portion of the polymerization and hence does not need cleaning out between consecutive runs.
DETAILED DESCRIPTION OF THE INVENTION
The copolymers prepared by the instant semicontinuous process contain 25 to 55 percent by weight, preferably 30 to 50 percent by weight, of a monovinyl aromatic compound and 45 to 75 percent by weight, preferably 50 to 70 percent by weight, of a conjugated diene having 4 to 8 carbon atoms. The copolymers have the general formula (A--B) m X where A is a non-elastomeric polymer segment based on the total monovinyl aromatic compound, B is an elastomeric segment based on the conjugated diene, m is an integer between 3 and 20, preferably between 7 and 12, and X is the radical of a polyfunctional coupling agent forming the nucleus of the star-block copolymer.
The semi-continuous process involves four separate reactors arranged such that contents of each reactor can be rapidly transferred into the next reactor.
In the first reactor, the total amount of monovinyl aromatic compound is polymerized in an inert solvent using a hydrocarbyllithium initiator to form linear segments (A--Li) of the monovinyl aromatic compound having lithium ions at the ends. The polymerization is allowed to proceed to essential completion.
In the second reactor, the conjugated diene is added and allowed to proceed to essentially complete conversion to form A-B-Li linear blocks.
In the third reactor, a polyfunctional coupling agent is added to the solution of A-B-Li segments and allowed to couple the segments into the radial block copolymer of general formula (A--B) m X, where m is an integer between 3 and 20, A is the nonelastomeric polymer segment based on the total monovinyl aromatic compound, B is an elastomeric polymer segment based on the conjugated diene and X is the radical of the polyfunctional coupling agent.
In the fourth reactor, the polymerization mixture is terminated by the addition of alcohol, preferably methanol, stabilizers are added and the polymer recovered by known means. The final recovery may be made by storing the stabilized product from the fourth reactor in a storage tank until sufficient product is accumulated to permit devolatilization extrusion to pellets to be undertaken.
At the appropriate time in the preparation of the rubber block in the second reactor, preparation for another run can begin in the first reactor. While the reaction of the initial run continues in the second vessel, a styrene front block for the second run is underway and will follow through the subsequent polymerization steps of the first run, etc. for additional runs in tandem--forming a semi-continuous process.
The monovinyl aromatic compound useful in the invention is preferably styrene, but may be alkyl substituted styrenes which have similar copolymerization characteristics, such as, alphamethylstyrene and the ring substituted methylstyrenes, ethylstyrenes and t-butylstyrene.
The amount of monovinyl aromatic compound useful in the invention is between 25 and 55 percent by weight, and preferably 30 to 50 percent by weight, based on the total weight of monomers utilized.
The hydrocarbyllithium initiators useful in the invention are the known alkyllithium compounds, such as methyllithium, n-butyllithium, sec-butyllithium; the cyclo-alkyllithium compounds, such as cyclo-hexyllithium; and the aryllithium compounds, such as phenyllithium, p-tolyllithium and naphthyllithium. All of the initiator must be added in the first reactor to initiate the monovinyl aromatic compound.
The amounts of hydrocarbyllithium added should be between 0.2 and 10.0 millimoles per mole of monomer. The total amount of initiator used depends on the molecular weight and number of polymer chains desired.
The conjugated dienes useful in the invention are those having from 4 to 8 carbon atoms in the molecule, such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene and mixtures thereof.
The polymerization is conducted in an inert hydrocarbon solvent such as isobutane, pentane, cyclohexane, benzene, toluene, xylene and the like. The polymerization is carried out in the absence of air, moisture, or any other impurity which is known to be detrimental to anionic catalyst systems.
The polyfunctional coupling agents suitable for the invention may be any of the materials known to have functional groups which can react with carbon to lithium bonds to add the carbon chain to the functional group. Typical examples of the suitable coupling agents are the polyepoxides, such as epoxidized linseed oil; the polyesters such as diethyl adipate; the polyhalides, such as silicon tetrahalide; the polyisocyanates, such as benzene-1,2,4-triisocyanate; the polyimines, such as tri(1-aziridinyl) phosphine oxide; the polyaldehydes, such as 1,4,7-naphthalene tricarboxaldehyde; the polyketones, such as 2,4,6-heptanetrione; the polyanhydrides, such as pyromellitic dianhydride; and the polyacid chlorides, such as mellitic acid chloride. Especially useful, and preferred herein, are the polyvinyl aromatic compounds such as divinylbenzene, which although only difunctional as monomers, can polymerize to form polyfunctional agents in situ and serve as coupling agents. Suitable are the ortho-, meta-, or paradivinylbenzenes, or mixtures thereof.
The amount and type of coupling agent used is dependent upon the number of polymer chains having lithium terminated ends and the number of arms desired per star-block molecule. Thus, for agents having a fixed number of functional groups such as silicon tetrachloride, an equivalent of agent per equivalent of lithium terminated polymer chains, gives a four armed star-block copolymer. In the case of difunctional agents which polymerize during the coupling reaction, such as divinylbenzene, the amounts of agent to be used must be determined for the conditions of reaction, since the number of equivalent functional sites is variable. However, the amounts will vary only from 0.5 to 3.5 parts by weight, and preferably 0.8 to 2.0 parts by weight, of divinylbenzene per 100 parts by weight of total monomers.
The polymerization process for preparing the star-block copolymers consists essentially of:
a. charging a first reactor with the solvent and all of the initiator and heating to 70° to 85° C., followed by the addition in 3 equal portions, over a period of from 6 to 15 minutes of all of the monovinyl aromatic compound while maintaining the reactor at polymerization temperature;
b. transferring the contents of the first reactor to a second reactor and charging the conjugated diene in 3 equal portions over a period of 27 to 55 minutes while maintaining the second reactor at a temperature of from 65° to 85° C.;
c. transferring the contents of the second reactor to a third reaction and charging 0.5 to 3.5 parts by weight of coupling agent per 100 parts by weight of total monomers and allowing to couple at 65° to 80° C. for 30 to 60 minutes to form star-block copolymer;
d. transferring the contents of the third reactor to a fourth reactor, terminating the polymerization by the addition of methanol and adding stabilizers to the mixture and recovering the polymer by extrusion into polymer pellets; and
e. repeating steps a-d as soon as each reactor is emptied into the succeeding reactor.
The monomers in step a and b a added in three portions to allow temperature control without the danger of thermal runaways.
Since each reactor is used for only one reaction, the reactors do not need to be cleaned out between runs and the process can be run more economically and in shorter times than the equal batch process.
The following example is given to illustrate the invention, but not to limit the claims. All parts and percentages are by weight unless otherwise specified.
EXAMPLE I
A. Preparation of a star-block copolymer having 46/54 ratio of styrene/butadiene in the arms by a batch polymerization process
A one gallon stirred reactor was charged with 1,800 g. of purified cyclohexane and heated to 70° C. A trace of diphenylethylene (0.2 g) was added to the cyclohexane by means of a hypodermic needle. A solution of secbutyllithium in cyclohexane was added to the reactor portionwise until a permanent orange-yellow color was obtained. The solution was then backtitrated with cyclohexane until the color just disappeared. The solvent and reactor were now ready for the polymerization of monomer. Into the closed reactor was charged 13.7 m moles of secbutyllithium and 308 g of styrene and the reactor held at 60° C. for 20 minutes. Analysis of the solution by U.V. analysis showed that less than 0.01% by weight of the styrene monomer remained. Number average molecular weights (M n ) of the polystyrene blocks were determined by Gel Permeation Chromatography to be 28,000. At this point, 361 g of butadiene was added to the reactor and the whole mixture held for 60 minutes to complete the polymerization of the butadiene. The diblock arms thus formed were analyzed by refractive index and found to be 46% by weight styrene and 54% butadiene. There was then added 15.7 ml of divinylbenzene of 55% purity and the whole was held for 75 minutes at 70° C. to complete the linking reaction. The system was terminated by the addition of 1 g of methanol. The polymer solution was transferred to a 5 gallon polyethylene liner, diluted further with acetone and the polymer was precipitated by adding isopropanol under high speed stirring. The polymer was then treated with 0.5 part Polygard HR, a commercial antioxidant, and 0.5 part 2,6, ditert-butyl-4-methylphenol per 100 parts by weight of polymer. The wet polymer was dried at 50° C. in an oven under vacuum at less than 100 microns of mercury.
The resulting star-block polymer was found to have about 8 linear arms. Each arm has M n of about 60,900, made up of a polystyrene block of M n 28,000 and a polybutadiene block of M n 32,900. The divinylbenzene was present in an amount of 1.2 parts per hundred of monomer (phm).
B. Preparation of a star-block copolymer having 46/54 ratio of styrene/butadiene in the arms by a semicontinuous polymerization process.
A one gallon stirred reactor was charged with 1910 g of purified cyclohexane, heated at 83° C. and titrated with sec-butyllithium, as in Example IA, to sterilize solvent and reactor. Into the closed reactor was charged 11.06 millimoles of sec-butyllithium and 294 g of styrene in 3 equal batch additions while maintaining the reactor at 83° C. over 6 minutes to ensure complete polymerization of all the styrene to polystyryl chains terminated by active lithium ions. Number average molecular weight (M n ) of the polystyrene blocks were determined by Gel Permeation Chromatography to be 29,400.
The reactor contents were transferred to a second one gallon reactor and this second reactor was then charged with 3 equal 183 g portions of butadiene and allowed to polymerize for times of 12, 12 and 18 minutes, while being maintained at 80° C. The diblock arms thus formed were analyzed by refractive index and found to be 46% by weight styrene and 54% butadiene.
The mixture was then transferred to a third one gallon reactor. There was then added 17.33 ml (66.03 millimoles) of divinylbenzene of 55% purity and the whole held at 80° C. for 30 minutes to complete the coupling reaction. The mixture was then transferred to a fourth reactor and the polymerization terminated by the addition of alcohol as in Example IA. Total reaction time was 78 minutes, compared to 155 minutes for the batch process in Example IA.
The resulting star-block copolymer was found to have about 11 linear arms. Each arm has M n of about 64,000 made up of a polystyrene block of M n 29,400 and a polybutadiene block of M n 34,600.
Again, as in Example IB, it is possible to prepare a second run in the first reactor while the second reactor is being used for the diene polymerization.
The Gel Permeation Chromatograph of the finished star-block copolymers showed that the semi-continuous process described herein gave less polystyrene and diblock copolymers, caused by early termination of the lithium-terminated polymers, than the batch process. It was also apparent, from the fact that the product from semi-continuous process had 11 arms compared to 8 for the comparable batch process, that greater coupling occurred during the semi-continuous process.
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A semi-continuous process for the preparation of star-block copolymers of 25-55% by weight of monovinyl aromatic compound and 45-75% by weight of conjugated diene monomer has been developed. The process reduces the time needed to produce the copolymer by shortening reaction time and eliminating the need for costly cleanout between runs.
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RELATED APPLICATIONS
[0001] Applicant claims the benefit of provisional application 60/959,782, filed Jul. 18, 2007.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to anchors used in supporting articles on walls or doors, and in particular, the present invention relates to anchors for use on hollow walls and doors yet has application to solid walls and doors.
[0004] 2. Description of the Prior Art
[0005] Hollow walls, which comprise most interior walls of building are generally comprised of a gypsum board, plaster board, drywall, or the like of a thickness generally of ½ to ⅝ths of an inch. This wall board is normally mounted on parallel, vertically oriented studs, thus forming a hollow or cavity defined by two adjacent studs and the wall board sheathing.
[0006] A similar situation rises in interior doors, which are often time framed out and covered by a thin wooden veneer on both sides, which again creates hollows or cavities in the door defined as a space between the framing and the opposing veneer sheathing.
[0007] The gypsum board, plaster board, door sheathing, drywall or plaster are of limited structural integrity and in the case of gypsum board, dry wall or plaster board owe much of its strength to the paper used to enclose the compressed powder. They will not adequately support items hung thereon with simple nails, or even standard screws, unless the fasteners in the form of nails or screws pass through the gypsum board, drywall, plaster board or the like and are anchored in one of the interior studs. Since these studs are spaced apart per construction codes, an interior wall has significantly greater hollow space than it does solid space (i.e. drywall stud drywall).
[0008] As a result of this excess hollow space, the homeowner oftentimes finds himself having to anchor a fastener in an interior wall in a location in which the fastener only penetrates the gypsum board, plaster board or drywall or the like. This need could be for hanging a decorative item, such as a painting or mirror, or for hanging utility items, such as shelving.
[0009] There are a myriad of hollow wall anchors which have been developed and are used in conjunction with a nail or screw for enhancing holding strength in these situations. Common anchors of this type often have drawbacks. Plug anchors made of metal, plastic or fiber which are expanded by an inserted screw against the interior gypsum of the wall board still rely on the tenuous holding strength provided by compressed powder gypsum. Other anchors include toggle bolts, which cannot be reused and which require pre-drilled holes for installation. Self-installing drive-in molly bolt anchors may damage a wall if not properly installed. Many of the hollow wall anchors are susceptible to loosening and failure, particularly with a dynamic load, such as the removal and replacement of pictures or paintings or other typical wall vibrations.
[0010] Still further, many anchors exert a spreading force on their apertures, which is not always reliable and secure, and can cause the fastener to fail over time under heavier weight loads. Self-drilling anchors leave a large hole in the drywall, and are not useful for thin panels such as sheathing veneer on hollow doors, or on plaster. Metal toggle bolts require a large hole and are not normally useful in hollow doors or plaster. Molly bolts are not useful for hollow doors or plasters, and are difficult to remove, leaving a large hole in the drywall.
[0011] Each of the aforesaid prior art anchors are also susceptible to be easily over-tightened such that they distort the drywall, gypsum board or plaster board, which affects the aperture through which they are inserted, and thus may weaken their intended purpose.
[0012] Applicant's novel contribution to the art addresses the shortcomings of the prior art fasteners and introduces a unique two-piece design anchor requiring a small aperture in which does not distort the surface and eliminates the possibility of over-tightening, and in many instances, presents an anchor which can be reused. Applicant's anchor also has application not only to hollow walls and doors, but also solid walls and doors.
OBJECTS OF THE INVENTION
[0013] An object of the present invention is to provide for a novel hollow wall anchor of two-piece design which does not distort the surface through which it is inserted, and which eliminates the possibility of over-tightening so as to deform or distort the anchoring material.
[0014] A still further object of the present invention is to provide for a unique hollow wall fastener of two-piece construction wherein the two pieces are interchangeable such that the fastener can accommodate wall material of different thicknesses.
[0015] A still further object of the present invention is to provide for a novel hollow wall fastener which can be reused.
[0016] A still further object of the present invention is to provide for a novel fastener anchor for solid walls and doors.
SUMMARY OF THE INVENTION
[0017] An anchor for a screw fastener for hollow walls and doors and solid walls and doors, the anchor of two-piece construction having a nose piece with conical end portion and a cooperative lock nut which is drawn over the conical end portion of the nose piece upon influence of rotation of the screw causing the lock nut fingers to flare out and engage the interior surface of a hollow wall or the circumferential surface of a bore in a solid wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other objects of the present invention will become apparent, particularly when taken in light of the following illustrations wherein:
[0019] FIG. 1 is an exploded side view of the anchor of the present invention;
[0020] FIG. 2 is a side view of the anchor of the present invention in the course of being installed to a hollow wall;
[0021] FIG. 3 is a side view of the anchor of the present invention in a fully fixed, secure, installed position in a hollow wall;
[0022] FIG. 4 is a side view of the anchor of the present invention utilized to secure an object to a solid wall; and
[0023] FIG. 5 is a partial end view of a portion of the anchor assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 1 is an exploded view of the anchor 10 of the present invention, FIG. 2 is a side view of the anchor 10 of the present invention in the course of being installed to a hollow wall, FIG. 3 is a side view of the anchor 10 of the present invention fully installed in a hollow wall, and FIG. 5 is a partial end view of a finger of the lock nut assembly.
[0025] Anchor 10 is of two piece construction having a nose piece 12 and a cooperative lock nut 14 . Nose piece 12 comprises a barrel member 16 of generally cylindrical construction having a truncated conical end portion 18 and a flange end 20 . Centrally disposed through both the flange end 20 , barrel member 16 and truncated conical end portion 18 , is a throughbore 22 .
[0026] Formed about the circumference of barrel member 16 are a plurality of axial upstanding ridges 24 in parallel relationship with throughbore 22 . Formed on truncated conical end portion 18 are a plurality of slots or voids 26 which radiate from truncated conical end 23 towards barrel member 16 .
[0027] Lock nut 14 is tubular in shape having a threaded throughbore 23 . First end 32 of lock nut 14 is formed with a plurality of fingers 34 , the number of fingers 34 being equal to the number of slots or voids 26 formed on truncated conical end portion 18 of nose piece 12 . Fingers 34 have a concave profile in order to cooperate with truncated conical end portion 18 of nose piece 12 (See FIG. 5 ). Formed on the inner surface 36 of fingers 34 are upstanding ridges 38 . Upstanding ridges 38 are slidably receivable within slots or voids 26 on nose piece 12 as hereinafter described. In the preferred embodiment, the leading edge of upstanding ridges 38 would be beveled or rounded for ease of engagement with slots or voids 26 .
[0028] Referring to FIGS. 2 and 3 and the installation of anchor 10 , the appropriate location on the wall 50 would be identified for the installation of the anchor. A suitable aperture would be drilled into wall 50 . The diameter of the aperture would approximate the diameter of the barrel member 16 of nose piece 12 absent axial upstanding ridges 24 . This aperture would normally be in the range of from quarter to five sixteenths of an inch. The hook 52 or other piece of hardware to be positioned on the wall would be juxtaposed flange end 20 of nose piece 12 . A threaded fastener 54 , in the form of the screw, would then be inserted through the aperture 56 in the hardware, through throughbore 22 of nose piece 12 and into threaded inner tubular throughbore 22 of lock nut 14 . Threaded fastener 54 would then be rotated, engaging the threaded inner tubular throughbore 22 of locknut 14 so as to draw locknut 14 towards nose piece 12 such that the upstanding ridges 38 on fingers 34 of locknut 14 engage with slots or voids 26 on truncated conical end portion 18 of nose piece 12 .
[0029] With the nose piece 12 and lock nut 14 assembly thus completed, the lock nut 14 and nose piece 12 are inserted into the aperture formed in wall 50 until flange end 20 of nose piece 12 is juxtaposed the outer surface 51 of wall 50 . The hook or alternative hardware 52 is now similarly juxtaposed the outer surface 51 of wall 50 .
[0030] The threaded fastener 54 would then be further rotated so as to draw lock nut 14 towards barrel member 16 of nose piece 12 , which due to the cooperation between truncated conical end portion 18 and fingers 34 on lock nut 14 , causes the fingers 34 to bend or extend outwardly until as illustrated in FIG. 3 , the end tips of fingers 34 are juxtaposed the inner surface 53 of wall 50 . The bend or outward extension of fingers 34 is facilitated by annular grooves 32 formed in fingers 34 .
[0031] In the process just described, the axial ridges 24 on barrel member 16 of nose piece 12 prevent the rotation of nose piece 12 by engaging the wall 50 about the periphery of the drilled aperture.
[0032] The upstanding ridges 38 on fingers 34 cooperate with the slots or voids 26 on truncated conical end portion 18 of nose piece 12 to prevent locking nut 14 from freely rotating. Therefore, under the influence of the threaded fastener 54 , locking nut 14 must move axially towards nose piece 12 , thus causing fingers 34 to bend or spread outwardly so as to engage the inner surface 53 of wall 50 .
[0033] FIG. 4 is a side view of anchor 10 being utilized with respect to a solid wall. The structure of anchor 10 remains the same. An appropriate aperture is drilled into the solid wall 60 . Anchor 10 and the hardware 52 that it is to secure is then inserted into the aperture until flange end 20 is juxtaposed the outer surface 61 of the solid wall 60 . The threaded fastener 54 is then rotated which causes fingers 34 on lock nut 14 to spread such that they frictionally engage the inner surface 63 of the bore 64 which was drilled resulting in a firm fastening of all components.
[0034] Therefore, while the present invention has been disclosed with respect to the preferred embodiments thereof, it will be recognized by those of ordinary skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore manifestly intended that the invention be limited only by the claims and the equivalence thereof.
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An anchor for a screw fastener for hollow walls and doors and solid walls and doors, the anchor of two-piece construction having a nose piece with conical end portion and a cooperative lock nut which is drawn over the conical end portion of the nose piece upon influence of rotation of the screw causing the lock nut fingers to flare out and engage the interior surface of a hollow wall or the circumferential surface of a bore in a solid wall.
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[0001] This application claims the benefit of U.S. Provisional Application No. 60/584,414, filed Jun. 30, 2004, and is a continuation-in-part of U.S. patent application Ser. No. 10/746,913, filed Dec. 23, 2003, which claims the benefit of Danish Patent Application No. PA 2002 02005, filed Dec. 23, 2002, all of which are hereby incorporated by reference in their entireties.
FIELD OF INVENTION
[0002] The present invention is directed to a crystalline escitalpram hydrobromide ((S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofuran carbonitrile hydrobromide), pharmaceutical compositions containing the same, and methods of preparing the same.
BACKGROUND OF THE INVENTION
[0003] Citalopram is a well known antidepressant drug that has been widely sold for many years and has the following structure
It is a selective, centrally acting serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor accordingly having antidepressant activities. Citalopram was first disclosed in DE 2,657,013 corresponding to U.S. Pat. No. 4,136,193.
[0004] The S-enantiomer of citalopram (escitalopram) has the formula
and was described along with its antidepressant effect in U.S. Pat. No. 4,943,590. EP patent application 1.200.081 describes the use of escitalopram for the treatment of neurotic disorders and WO02/087566 describes the use of escitalopram for the treatment of depressed patients who have failed to respond to conventional selective seritonin reuptake inhibitors (SSRI's) in addition to other disorders.
[0005] Methods for the preparation of escitalopram are disclosed in U.S. Pat. No. 4,943,590. This patent also describes the free base of escitalopram as existing as an oil as well as the oxalic, pamoic and L-(+)-tartaric acid addition salts of escitalopram.
[0006] In the search for salts of escitalopram suitable for pharmaceutical composition more than 30 organic and inorganic acids were investigated under different conditions. These acids gave either oils or amorphous solids having moderate to high hygroscopic properties. The non-hydroscopic crystalline solids were formed from non-carboxylic organic acids, indeed most of the addition salts formed with monocarboxylic organic acids. Di- and triphasic organic acids gave amorphous solids as did the salt formed with L-tartaric acid.
[0007] Thus, very few crystalline stable, non-hydroscopic salts of escitalopram are known.
SUMMARY OF THE INVENTION
[0008] The present invention provides crystalline escitalopram hydrobromide ((S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofuran carbonitrile hydrobromide), and a novel crystalline form of escitalopram hydrobromide referred to herein as Form I. Form I is stable, water soluble, and not hygroscopic at a relative humidity less than 70%.
[0009] Another embodiment is a pharmaceutical composition comprising crystalline escitalopram hydrobromide (such as Form I escitalopram hydrobromide) and, optionally, a pharmaceutically acceptable excipient. According to one embodiment, the pharmaceutical composition comprises a therapeutically effective amount of crystalline escitalopram hydrobromide or crystalline Form I of escitalopram hydrobromide. For example, the pharmaceutical composition can comprise an amount of crystalline escitalopram hydrobromide or crystalline Form I escitalopram hydrobromide effective to treat escitalopram-treatable disorders in a subject, such as a mammal (e.g. human). According to one preferred embodiment, the pharmaceutical composition comprises at least about 20, 30, 40, 50, 60, 70, 80, 90, 95, 96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, or 99.9% by weight of crystalline escitalopram hydrobromide or crystalline Form I of escitalopram hydrobromide, based upon 100% total weight of escitalopram hydrobromide in the pharmaceutical composition. According to another preferred embodiment, the pharmaceutical composition comprises at least about 20, 30, 40, 50, 60, 70, 80, 90, 95, 96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, or 99.9% by weight of Form I of escitalopram hydrobromide, based upon 100% total weight of crystalline escitalopram hydrobromide in the pharmaceutical composition. The pharmaceutical composition may be in the form of a unit dosage form, such as a tablet or capsule. According to one embodiment, the unit dosage form contains from about 2.5 to 20 mg of escitalopram hydrobromide (such as 5, 7.5, or 10 mg) (calculated based on the weight of escitalopram free base).
[0010] Yet another embodiment is a method of treating a subject (such as a mammal (e.g., human)) having an escitalopram-treatable disorder comprising administering a therapeutically effective amount of a pharmaceutical composition comprising crystalline escitalopram hydrobromide or crystalline Form I of escitalopram hydrobromide.
[0011] Yet another embodiment is a method for preparing crystalline escitalopram hydrobromide comprising the steps of:
(a) forming an anhydrous solution of escitalopram hydrobromide and at least one organic solvent (e.g., iso-propanol); and (b) precipitating crystalline escitalopram hydrobromide from the anhydrous solution.
[0014] Yet another embodiment is a method for preparing crystalline escitalopram hydrobromide comprising the steps of:
(a) dissolving escitalopram free base in iso-propanol; (b) adding aqueous hydrobromic acid; (c) drying the solution (such as by azeotropic distillation or adding a solid drying agent); and (d) precipitating crystalline escitalopram hydrobromide from the solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a characteristic X-ray powder diffraction (XRPD) pattern for Form I of escitalopram hydrobromide.
[0020] FIG. 2 is a drawing derived from the crystal structure of Form I of escitalopram hydrobromide, that shows the conformation of the molecule in the structure.
[0021] FIG. 3 is a differential scanning calorimetry (DSC) thermogram of Form I of escitalopram hydrobromide.
[0022] FIG. 4 is a thermogravimetric analysis (TGA) thermogram of Form I of escitalopram hydrobromide.
[0023] FIG. 5 is a dynamic vapor sorption (DVS) plot of Form I of escitalopram hydrobromide.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The term “about” generally means within 10%, preferably within 5%, and more preferably within 1% of a given value or range. With regard to a given value or range in degrees 2θ from XRPD patterns, the term “about” generally means within 0.2° 2θ and preferably within 0.1°, 0.05°, or 0.01° 2θ of the given value or range. Alternatively, the term “about” means within an acceptable standard error of the mean, when considered by one of ordinary skill in the art.
[0025] The term “escitalopram hydrobromide” refers to (S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofuran carbonitrile hydrobromide.
[0026] A “pharmaceutically acceptable excipient” refers to an excipient that is useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable, and includes an excipient that is acceptable for veterinary use as well as human pharmaceutical use. A “pharmaceutically acceptable excipient” as used in the present application includes both one and more than one such excipient. Suitable pharmaceutically acceptable excipients include, but are not limited to, carriers, diluents, flavorants, sweeteners, preservatives, dyes, binders, suspending agents, dispersing agents, colorants, disintegrants, lubricants, plasticizers, edible oils, and any combination of any of the foregoing.
[0027] “Treating” or “treatment” of a state, disorder or condition includes:
[0028] (1) preventing or delaying the appearance of clinical symptoms of the state, disorder or condition developing in a mammal that may be afflicted with or predisposed to the state, disorder or condition but does not yet experience or display clinical or subclinical symptoms of the state, disorder or condition,
[0029] (2) inhibiting the state, disorder or condition, i.e., arresting or reducing the development of the disease or at least one clinical or subclinical symptom thereof, or
[0030] (3) relieving the disease, i.e., causing regression of the state, disorder or condition or at least one of its clinical or subclinical symptoms. The benefit to a subject to be treated is either statically significant or at least perceptible to the patient or to the physician.
[0031] A “therapeutically effective amount” means the amount of escitalopram hydrobromide that, when administered to a mammal for treating a state, disorder or condition, is sufficient to effect such treatment. The “therapeutically effective amount” will vary depending on the state, disorder or condition and its severity and the age, weight, physical condition and responsiveness of the subject to be treated.
[0032] “Escitalopram-treatable disorders” include, but are not limited to, depression (e.g., major depression disorder and treatment of patients which failed to respond to initial treatment with conventional selective serotonin reuptake inhibitors (SSRIs)), neurotic disorders (including, but not limited to, panic attacks (including, but not limited to, panic attacks associated with panic disorder, specific phobias, social phobia and agoraphobia), post traumatic stress disorder, obsessive compulsive disorder, and anxiety states such as generalized anxiety disorder and social anxiety disorder), acute stress disorder, eating disorders (such as bulimia, anorexia and obesity), phobias, dysthymia, premenstrual syndrome, premenstrual dysphoric disorder, cognitive disorders, impulse control disorders, attention deficit hyperactivity disorder, and drug abuse. The term “escitalopram-treatable disorders” also includes disorders for which escitalopram is known to be an effective treatment, such as those described in International Publication Nos. WO 01/03694 and WO 02/087566, both of which are incorporated by reference.
Form I of Escitalopram Hydrobromide
[0033] Form I has a distinct XRPD pattern as shown in FIG. 1 . The term “Form I” as used herein refers to crystalline forms of escitalopram hydrobromide having this and substantially related XRPD patterns. Positions of some characteristic reflections in the XRPD pattern (using CuK α1 radiation) of Form I are provided in Table 1 below. The peak (expressed in degrees 2θ±0.10°) at 21.9 is characteristic of Form I. Other characteristic peaks (expressed in degrees 2θ±0.1°) include those at 16.95, 18.59, 21.1, and 27.76. Form I has a melting point onset as measured by differential scanning calorimetry at from about 131 to about 135° C. (see, e.g., FIG. 3 ). FIG. 5 shows the dynamic vapor sorption (DVS) curves for Form I. As shown by FIG. 5 , Form I of escitalopram hydrobromide is non-hygroscopic at a relative humidity less than about 70%. At a relative humidity above 70%, the escitalopram hydrobromide absorbs water and turns into a sticky oil. Subsequent drying of the sticky oil does not return the escitalopram hydrobromide to a crystalline solid.
TABLE 1 Characteristic XRPD Peaks (expressed in degrees 2θ ± 0.1° 2θ) and Intensities of Diffraction Lines for Form I Degrees 2θ(±0.2° 2θ) 6.760 8.640 12.910 14.960 16.950 18.590 19.050 20.410 21.100 21.930 24.940 25.750 26.990 27.420 27.760 29.430 29.870
[0034] Form I exhibits a single crystal X-ray crystallographic analysis at 122±2 K with crystal parameters that are approximately equal to the following:
Parameter Form I Space group Orthorhombic P2,2,2, Cell Dimensions a(Å) 6.5456(8) Å b(Å) 11.0611(6) Å c(Å) 25.795(3) Å Volume (Å 3 ) 1867.6(3) Z (molecules/unit cell) 4 Density 1.442 g/cm 3
(the numbers in parenthesis are standard deviations on the last digit)
A drawing derived from the crystal structure of Form I of escitalopram hydrobromide, that shows the conformation of the molecule in the structure is shown in FIG. 2 .
[0035] The atomic positions in Form I are provided in tables 2 and 3 below.
TABLE 2 Atomic Coordinates (non-H atoms) label x y z F(18) 0.4146(2) 0.29703(11) 0.88097(5) O(2) 1.01516(18) 0.73348(11) 0.90561(4) N(1) 0.5995(3) 1.24705(16) 1.03267(6) N(22) 1.0109(2) 0.61741(12) 0.70490(5) C(1) 0.8097(3) 0.74810(14) 0.88553(6) C(3) 1.0350(3) 0.79270(16) 0.95471(7) C(4) 0.8639(2) 0.88254(14) 0.95558(6) C(5) 0.8340(3) 0.98174(15) 0.98712(6) C(6) 0.6599(3) 1.05267(14) 0.97856(6) C(7) 0.5192(3) 1.02336(15) 0.93982(6) C(8) 0.5526(2) 0.92303(17) 0.90804(6) C(9) 0.7266(2) 0.85409(14) 0.91616(6) C(10) 0.6271(3) 1.16083(17) 1.00909(7) C(12) 0.6915(3) 0.62971(14) 0.89181(6) C(13) 0.7886(3) 0.52656(15) 0.91024(6) C(14) 0.6941(3) 0.41417(16) 0.90792(6) C(15) 0.5023(3) 0.40822(17) 0.88644(7) C(16) 0.3959(3) 0.50842(18) 0.87030(7) C(17) 0.4914(3) 0.62002(15) 0.87308(7) C(19) 0.8277(3) 0.77951(13) 0.82781(6) C(20) 0.9313(3) 0.68157(15) 0.79576(7) C(21) 0.9153(3) 0.71288(15) 0.73841(6) C(23) 1.2319(3) 0.59875(19) 0.71576(7) C(24) 0.9768(4) 0.64550(19) 0.64904(7) Br(0) 0.32633(2) 0.915787(14) 0.772754(7)
[0036]
TABLE 3
Atomic Coordinates (H atoms)
label
x
y
z
H(3A)
1.161(4)
0.8295(19)
0.9562(8)
H(3B)
1.029(3)
0.7323(19)
0.9830(7)
H(5)
0.929(3)
1.0060(18)
1.0131(8)
H(7)
0.410(3)
1.074(2)
0.9357(8)
H(8)
0.462(3)
0.9063(19)
0.8806(8)
H(13)
0.919(4)
0.532(2)
0.9239(8)
H(14)
0.758(3)
0.345(2)
0.9189(8)
H(16)
0.265(4)
0.497(2)
0.8551(10)
H(17)
0.420(4)
0.689(2)
0.8621(9)
H(19A)
0.695(3)
0.7955(17)
0.8151(7)
H(19B)
0.908(3)
0.8523(19)
0.8248(8)
H(20A)
0.870(3)
0.6028(17)
0.8011(7)
H(20B)
1.077(4)
0.681(2)
0.8060(9)
H(21A)
0.775(3)
0.7196(19)
0.7271(8)
H(21B)
0.993(3)
0.7871(16)
0.7301(7)
H(23A)
0.941(3)
0.550(2)
0.7124(8)
H(23B)
1.290(4)
0.545(2)
0.6891(9)
H(23C)
1.246(4)
0.559(2)
0.7496(10)
H(24A)
1.305(4)
0.672(2)
0.7171(9)
H(24B)
1.040(3)
0.584(2)
0.6279(8)
H(24C)
1.040(4)
0.717(2)
0.6430(10)
[0037] Crystalline escitalopram hydrobromide and crystalline Form I of escitalopram hydrobromide may be prepared by precipitating it from an anhydrous solution of escitalopram hydrobromide and at least one organic solvent.
[0038] Suitable organic solvents include, but are not limited to, iso-propanol, toluene, methyl t-butyl ether, a mixture of methyl t-butyl ether and isopropanol, tetrahydrofuran, butanone, n-butanol, iso-butanol, tert-butanol, a mixture of tert-butanol and isopropanol, 2-butanol, methyl iso-butyl ketone, 2-methyl-tetrahydrofuran, 1,4-dioxane, diethyl ether, ethyl acetate, acetone, and any combination of any of the foregoing. A preferred organic solvent is iso-propanol. Preferably, the organic solvent is one that does not readily pick up water (i.e., is not hygroscopic).
[0039] The anhydrous solution may be formed by introducing hydrobromide gas (e.g., by bubbling) into a solution of escitalopram free base and iso-propanol to form escitalopram hydrobromide. The solvent may be changed from iso-propanol to another organic solvent by concentrating the iso-propanol solution and dissolving the resulting escitalopram hydrobromide in at least one organic solvent (such as any of those mentioned above (e.g., acetone)) to form the anhydrous solution.
[0040] The anhydrous solution may also be formed by adding a solution of hydrobromide (e.g., 0.9-1.0 eq.) and iso-propanol to a solution of escitalopram free base (e.g., about 20% w/w) and iso-propanol. According to one embodiment, the addition is performed slowly such as by dropwise addition. The solvent may be changed from iso-propanol to another organic solvent (e.g., a 0.5 molar solution) by concentrating the iso-propanol solution and dissolving the resulting escitalopram hydrobromide in at least one organic solvent (such as any of those mentioned above (e.g., acetone)) to form the anhydrous solution.
[0041] Crystalline escitalopram hydrobromide and crystalline Form I of escitalopram hydrobromide may also be prepared by dissolving escitalopram free base in iso-propanol, adding aqueous hydrobromic acid (e.g., 0.9-1.0 eq.), and drying the solution to remove any water present. The drying can be performed by azeotropic distillation or repeated azeotropic distillation (e.g., with iso-propanol and toluene). The drying can also be performed by adding a solid drying (e.g., magnesium sulfate, molecular sieves) agent to the solution.
[0042] Escitalopram free base may be prepared by any method known in the art, such as those described in U.S. Pat. Nos. 4,593,590 and 6,566,540 and International Publication Nos. WO 03/000672, WO 03/006449, and WO 03/051861, all of which are hereby incorporated by reference.
EXAMPLES
[0043] The following examples are illustrative and are not meant to limit the scope of the claimed invention.
Example 1
[0044] (A) A 250 ml round bottom flask was charged with 5.7 g escitalopram free base and 120 ml isopropanol. The mixture was stirred until a homogenous solution was obtained. The mixture was cooled to 5° C. and HBr gas was bubbled in for 20 minutes with cooling. The mixture was placed in the refrigerator overnight. No solid material was formed. The mixture was then concentrated in vacuo to an oil and the oily residue was dissolved in acetone by heating to 45° C. (the solution was a 0.5 molar solution in acetone). The flask was scratched to initiate nucleation. The solution was cooled to 5° C. An off-white solid formed. The solid was collected, washed with cold acetone to give a crystalline material. The crystalline escitalopram hydrobromide was found by melting point, HPLC, and proton NMR to have a good purity. A sample of the material was exposed to air and it was found to be non-hygroscopic.
[0045] (B) Experiments with different solvents: These experiments were performed as follows: To a solution of the escitalopram free base (approx. 20% w/w) in dry iso-propanol was added dropwise 0.9-1.0 eq. of HBr (g) dissolved in dry iso-propanol. Precipitation of a solid normally occurred within 30 minutes. Where the precipitation was performed in a solvent other than iso-propanol, the resulting mixture was evaporated under reduced pressure and the appropriate solvent was added, evaporated again and the appropriate solvent given one more time to the mixture before final crystallisation.
[0046] Below is a table showing results from different solvents:
Precipitation of escitalopram hydrobromide from different solvents Solvent Yield Purity (HPLC) Melting Point Toluene 81% 99.1% 131° C. MTBE/IPA 72% 98.3% 132° C. (200:55) IPA 67% 99.4% 133° C. MTBE 93.4% 99.2% 131.6° C. THF 54.5% 99.95% 133.9° C. Butanone 30% 100% 133-134° C. n-Butanol 67% 99.9% 133-134° C. iso-Butanol 66% 99.6% 133-134° C. tert-Butanol/IPA (4:1) 82% 99.9% 133-134° C. 2-Butanol 85% 100% 133-134° C. MIBK 75% 100% — 2-methyl-THF 84% 100% — 1,4-Dioxane 65% 100% — Ether 91% 100% — EtOAc 88% 100% —
[0047] MTBE=methyl t-butyl ether; IPA=iso-propanol; MIBK=methyl iso-butyl ketone;
[0048] THF=tetrahydrofuran; EtOAc=ethyl acetate.
[0049] Other solvents, such as acetonitrile, methanol, ethanol and propylencarbonate, were tried, but gave no crystallisation:
Example 2
[0050] Form I of escitalopram hydrobromide was characterized as follows.
[0000] 1. X-Ray Powder Diffraction
[0051] X-ray powder diffraction analyses were carried out on a STOE Stadi P (available from STOE & CIE GmbH of Darmstadt, Germany) using Cu(Kα1) radiation. The parameters of the machine are shown below.
Diffractometer: STOE Stadi P Radiation: Cu(Kα1), germanium monochromator, λ=1.540598 Position Sensitive Detector (PSD) covering 7° Scan type: Stepscan, steps: 0.1°, 125-150 sec. pr. step Range: 5-45°2θ Sample measuring method: Transmission
[0058] The XRPD pattern for Form I prepared from an isopropanol and methyl t-butyl ether (MTBE) solution according to the procedure described in Example 1(B) is shown in FIG. 1 .
[0000] 2. Differential Scanning Calorimetry (DSC)
[0059] The melting point was determined using differential scanning calorimetry (DSC), using a TA instruments DSC 2920 (available from TA Instruments of New Castle, Del.) heating the sample 5°/min. The sample was placed in a covered pan. The DSC thermogram for Form I prepared from an isopropanol solution according to the procedure described in Example 1(B) is shown in FIG. 3 . The Form I sample had an onset temperature at about 134.3° C. and a peak maximum at about 136.3° C. The enthalpy of fusion was about 67 J/g (27 kJ/mol).
[0000] 3. Thermogravimetric Analysis (TGA)
[0060] The thermogram for Form I prepared from an isopropanol solution according to the procedure described in Example 1(B) is shown in FIG. 4 . The sample (1-5 mg) was heated 10°/min. on a TA Instruments TGA 2950 (available from TA Instruments of New Castle, Del.). No weight loss (<0.1%) was observed up to 150° C. Decomposition began at approximately 240° C.
[0000] 4. Dynamic Vapor Sorption (DVS)
[0061] Dynamic Vapour Sorption (DVS) measurements were performed in order to determine whether Form I (prepared from an isopropanol solution according to the procedure described in Example 1(B)) is hygroscopic. Two cycles were made starting at 20% relative humidity and then equilibrating at the following relative humidity values: 20-30-40-50-60-70-80-90-95-90-80-70-60-50-40-30-20-10-0-10-20.
[0062] In the first run no water was absorbed until the relative humidity exceeded 70%. At 80% relative humidity, 14% was absorbed. 14% corresponds to about 3.6 mol-equivalent of water. After this the escitalopram hydrobromide was very hygroscopic and at 95% relative humidity almost 9 mol-equivalent of water was absorbed.
[0063] The isotherm plot is shown in FIG. 5 .
[0000] 5. X-Ray Single Crystal Structure Determination
[0064] The diffraction data for Form I were collected on a Nonius KappaCCD diffractometer having the parameters in the table below. The crystal was cooled down to 122±2 K in a stream of N 2 gas. All H-atoms appeared in a difference map. Subsequently the positions and isotropic displacement parameters were refined. The atom numbering used is shown in FIG. 2 . The results are shown above.
Data Collection: Radiation MoK α , λ = 0.71073 Å Absorption coefficient: μ = 2.220 Absorption correction τ min = 0.40743, τ max = 0.85800 Temperature: T = 122(2) K Corrections: Lorentz-polarization hkl ranges: h = −9 → 9 K = −15 → 15 l = −36 → 34 No. of independent 4927 reflections: No. of reflections > 2sigma(I) 4122
[0065] The crystallographic drawing in FIG. 2 was obtained using the program ORTEP.
[0066] All references, including patents, patent applications, publications, and procedures, cited throughout this application are incorporated herein by reference in their entireties.
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The present invention provides crystalline escitalopram hydrobromide ((S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzo-furan carbonitrile hydrobromide), and a novel crystalline form of escitalopram hydrobromide referred to herein as Form I. Form I is stable, water soluble, and not hygroscopic at a relative humidity less than 70%.
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TECHNICAL FIELD
[0001] The present invention concerns a twelve-hour structure for thrust reverser, in particular with grids.
BACKGROUND
[0002] Traditionally, a thrust reverser with grids comprises two half-cowlings mounted each sliding on a half-beam mounted pivoting on a nacelle-holding mast.
[0003] The sliding movement of each half-cowling on its associated half-beam makes it possible to make the thrust reverser go from a direct jet configuration to a reverse jet configuration, and vice versa.
[0004] The rotational movement of each half-beam on the nacelle-holding mast makes it possible to make each half-cowling pivot relative to said mast for maintenance operations.
[0005] As illustrated in the appended FIGS. 1 and 2 , each half-beam 1 is formed in a ribbed metal alloy 3 , and typically comprises, on its outer face, primary 5 and secondary 7 rails capable of allowing the movement of the associated half-cowling (not shown), and a plurality of hinge yokes 9 a, 9 b, 9 c, 9 d capable of allowing the articulation of the half-beam 1 on the associated nacelle mast.
[0006] A receptacle 11 , mounted on the upstream part (relative to the direction of air flow in the nacelle) of the half-beam 1 , allows the fixing of a front frame designed to support the grids of the thrust reverser (frame and grids not shown).
[0007] As visible in FIG. 3 , the half-beam 1 is attached by riveting 13 on the upper part 15 of an internal fixed half-structure panel 17 , generally made of a composite material, and defining, with the associated thrust reverser cowling, the cold air jet 18 .
[0008] The assembly formed by the half-beam 1 , its rails 5 , 7 and its hinge yokes 9 a to 9 d is often referred to as “twelve-hour structure”, given its position at the top of the circle defined by a nacelle section, and by analogy with the dial of a watch.
BRIEF SUMMARY
[0009] The present invention aims in particular to provide a twelve-hour structure lightened relative to those of the prior art.
[0010] This aim of the invention is achieved with a twelve-hour structure for thrust reverser, comprising a half-beam capable of supporting a reverser half-cowling and including a plurality of hinges for the rotational mounting of said half-beam on a nacelle-holding mast, remarkable in that said half-beam is formed at least in part in composite material.
[0011] The use of composite material to manufacture this half-beam makes it possible to considerably lighten its weight.
[0012] According to other optional features of the present invention:
said half-beam also comprises at least one rail for slidingly mounting said half-cowling: such a rail is adapted to the case of a thrust reverser with grids; said half-beam is integrated into the upper part of an internal fixed half-structure panel: in this first embodiment, it is no longer necessary to rivet the half-beam on the internal fixed half-structure panel (this internal structure frequently being designated by “IFS”, i.e. Internal Fixed Structure), which makes it possible to save assembly/disassembly time; said half-beam comprises a foam core enveloped in the skin of said panel: this variation, in which the foam can be ROHACELL 110 WF, for example, makes it possible to obtain the desired rigidity for the half-beam while having a low weight; said half-beam comprises a case in composite material enveloped in the skin of said panel: this variation, in which the case can for example be in HEXPLY 914, makes it possible to save weight relative to the foam filling of the preceding variation; said hinge yokes are formed in a metal alloy; said half-beam comprises a core including one part in foam and a tube in composite material, this core being enveloped in the skin of said panel: this variation makes it possible to save weight relative to the first of the abovementioned variations, while using a standard composite tube, i.e. not specially formed for this particular use; said tube is formed in forged carbon: this material offers an excellent resistance/weight compromise; said rails and said hinge yokes sandwich said skin: this arrangement allows good resistance both of the rails and the hinge yokes; said half-beam is attached on the upper part of an internal fixed half-structure panel: this second embodiment can be adapted to a traditional internal fixed half-structure without requiring any modification of the latter; said half-beam comprises a closed case in composite material whereof one of the faces is formed by a plate supporting said at least one rail: such a half-beam can be manufactured by simple assembly of a small number of pieces; said half-beam comprises an open case in composite material integrating said at least one rail: this variation can be obtained by molding, for example of the “RTM” (Resin Transfer Molding) type, such molding making it possible to obtain a single-unit piece; said at least one rail is connected to said open case on a single face thereof: this variation can be obtained by drape molding of a single half-mold, the rails being placed in the other half-mold; said at least one rail is held between two layers of said open case: this variation, making it possible to obtain rails connected more closely to the rest of the case, requires the drape molding of two half-molds; said hinge yokes are formed in forged carbon: these yokes, which offer excellent resistance with a low weight, can be placed in the molds for the open case variations.
[0027] The present invention also relates to a nacelle for aircraft engine, remarkable in that it comprises a twelve-hour structure according to the preceding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Other features and advantages of the present invention will appear in light of the following description, and upon examining the appended figures, in which:
[0029] FIGS. 1 and 2 are perspective views of a twelve-hour structure of the prior art, mentioned in the preamble of the present description;
[0030] FIG. 3 is a transverse view of said twelve-hour structure, taken at one of the hinge yokes of said structure;
[0031] FIGS. 4 and 5 are transverse cross-sectional views of a first embodiment of a twelve-hour structure according to the invention, in running section and in the zone where one of the hinge yokes is found, respectively;
[0032] FIGS. 6 and 7 are views similar to FIGS. 4 and 5 of a variation of the first embodiment according to the invention;
[0033] FIG. 8 diagrammatically indicates all of the components making it possible to realize a twelve-hour structure according to FIGS. 6 and 7 ;
[0034] FIGS. 9 and 10 are views similar to FIGS. 4 and 5 of another variation of the first embodiment according to the invention;
[0035] FIG. 11 is an axial cross-sectional view of the tube forming the twelve-hour structure of FIGS. 9 and 10 , in the zone of one of the hinge yokes of said structure;
[0036] FIGS. 12 and 13 are views similar to FIGS. 4 and 5 of a second embodiment according to the invention;
[0037] FIG. 14 is a view similar to FIG. 8 of said second embodiment;
[0038] FIGS. 15 and 16 are views similar to FIGS. 4 and 5 of a variation of this second embodiment;
[0039] FIG. 17 diagrammatically indicates the manner in which the variation of FIGS. 15 and 16 can be obtained by molding;
[0040] FIG. 18 is a view similar to FIG. 4 of a third variation of the second embodiment according to the invention; and
[0041] FIG. 19 is a view similar to FIG. 17 of the molding operation of the structure of FIG. 18 .
[0042] In all of these figures, identical or similar references designate identical or similar members or sets of members.
DETAILED DESCRIPTION
[0043] In reference now to FIGS. 4 and 5 , one can see that, according to a first embodiment of the twelve-hour structure of the invention, the half-beam 1 is integrated into the upper part 15 of an internal fixed half-structure panel 17 .
[0044] More specifically, in the variation illustrated in FIGS. 4 and 5 , the half-beam 1 comprises a foam core 18 enveloped in the skin 19 situated on either side of the honeycomb structure 21 of the panel 15 .
[0045] The foam 18 , which can for example be a ROHACELL 110 WF foam, the skin 19 and the honeycomb structure 21 are made in a single co-curing operation.
[0046] A plate 23 integrating the primary 5 and secondary 7 rails, formed for example in a metal alloy, is fixed by riveting 25 on the skin 19 .
[0047] Preferably, between this plate 23 and this skin 19 is a profile 27 defining an aerodynamic shape suitable for the flow of cold air along the panel 15 .
[0048] As visible in FIG. 5 , in the zones of the hinges 9 a to 9 d, the skin 19 is interrupted and the foam 18 comprises housings 29 in which the hinge yokes are arranged ( 9 c in FIG. 5 ).
[0049] These hinge yokes are bolted on the plate 23 , thus sandwiching on one hand the aerodynamic profile 27 , and on the other hand the skin 19 .
[0050] In the alternative illustrated in FIGS. 6 and 7 , the foam core 18 is replaced by a monolithic case 31 , formed in composite material.
[0051] This case is preferably pre-cured, the skin 19 then being overmolded on this case.
[0052] FIG. 8 shows that the alternative illustrated in FIGS. 6 and 7 is formed by the assembly of a plurality of simple elements: skin parts 19 a, 19 b, 19 c , honeycomb structure 21 and monolithic case 31 .
[0053] The assembly of all of these simple elements is done by complete co-curing.
[0054] The fixing of the plate 23 and the yokes 9 a to 9 d is similar to that of the preceding alternative.
[0055] It is understood that, due to the hollow nature of the monolithic case 31 , this alternative allows a significant weight savings relative to the preceding alternative.
[0056] In the variation illustrated in FIGS. 9 to 11 , the skin 19 surrounds a tube 33 in composite material, connecting the hinge yokes 9 a to 9 d to each other.
[0057] This tube and these yokes can be realized for example in forged carbon, making it possible to obtain an excellent resistance/weight compromise.
[0058] In the zone between the honeycomb structure 21 and the tube 33 is a foam core 18 similar to that of the alternative of FIGS. 4 and 5 .
[0059] The plate 23 supporting rails 5 and 7 is connected to the panel 15 via the profile 27 .
[0060] In the zones where the hinge yokes 9 a to 9 d are found, this plate 23 is also bolted on these yokes, as is visible in FIG. 10 .
[0061] This alternative is interesting because it allows the use of forged carbon tubes 33 of standard dimension around which one tapes the skin 19 : one is thus freed from the need to design a custom piece, which makes it possible to reduce the manufacturing cost.
[0062] We will now look at FIGS. 12 to 14 , in which we have shown a second embodiment of the twelve-hour structure according to the invention.
[0063] In the embodiment illustrated in these three figures, this twelve-hour structure comprises a closed case 35 made in composite material, one of the faces of this case being defined by the plate 23 supporting the primary 5 and secondary 7 rails.
[0064] This plate can be formed in a metal alloy, or in “extruded” composite.
[0065] Contrary to the preceding embodiment, the case 35 is attached by bolting 37 on the upper part 15 of the internal fixed half-structure panel 17 .
[0066] As visible in FIGS. 12 and 13 , the profile 27 of aerodynamic form connecting the case 35 to the panel 15 can be held by the rivets 39 connecting the plate 23 to the rest of the case 35 .
[0067] FIG. 13 shows that the hinge yokes 9 a to 9 d, which can for example be formed in forged carbon, are placed inside the case 35 , and fixed to the panel 15 by rivets 37 .
[0068] FIG. 14 shows that this alternative can be formed by the assembly of simple elements: plate 23 , case half-shell 41 , hinge yokes 9 a to 9 d and fastening bolts 37 .
[0069] This FIG. 14 also shows that the plate 23 can advantageously comprise a return 43 designed to be held by the bolts 37 , thereby avoiding having to use rivets 39 .
[0070] Contrary to the previous embodiment, it is understood that this embodiment can be attached on a standard internal fixed half-structure 17 , thus not requiring any modification of the upper panel 15 of said structure.
[0071] In the alternative of this second embodiment illustrated in FIGS. 15 to 17 , the half-beam 1 of the twelve-hour structure according to the invention comprises an open case 45 formed by the drape molding of several layers of a composite material.
[0072] At the free ends 45 a, 45 b of said open case 45 are the rails 5 and 7 , also preferably formed by drape molding of several successive layers of composite material.
[0073] Inside the open case 45 are the hinge yokes 9 a to 9 d, as illustrated in FIG. 16 .
[0074] As visible in FIG. 17 , the twelve-hour structure illustrated in FIGS. 15 and 16 can be realized by molding in a mold 47 comprising a core 49 a and a matrix 49 b.
[0075] The preforms 51 a, 51 b defining the rails 5 and 7 are placed on the core 49 a and the composite material layers forming the case will be draped on these preforms 51 a, 51 b, and on the core 49 a.
[0076] One then closes the matrix 49 b on the core 49 a, and injects resin into the interface between said matrix and said core, thus making it possible to assemble the various elements forming the half-beam 1 (this molding method is traditionally known as “RTM”, or “Resin Transfer Molding”).
[0077] In the alternative illustrated in FIGS. 18 and 19 , one sees that one can advantageously form the open case 45 from two drape molding sub-assemblies 53 a, 53 b, clamping the rail preforms 51 a, 51 b.
[0078] This particular arrangement, which can also be obtained using a RTM-type method, allows a close connection of the rails 5 , 7 with the open case 45 , and therefore excellent resistance of the assembly.
[0079] As one can understand in light of the preceding, the two embodiments of the invention and their associated alternatives make it possible to obtain a twelve-hour structure half-beam whereof at least one part is realized in composite material, thereby allowing an important weight savings relative to the twelve-hour structures of the prior art.
[0080] Of course, the present invention is in no way limited to the embodiments described and illustrated, provided as simple examples.
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The invention relates to a twelve-hour structure for a thrust reverser, that comprises a half beam ( 1 ) capable of holding a reverser half cowling and including a plurality of hinge yokes ( 9 c ) for rotatingly mounting said half beam ( 1 ) on a nacelle-holding mast. The half beam ( 1 ) is at least partially made of a composite material.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority of U.S. Provisional Patent Application Ser. No. 60/016,351, filed on Apr. 30, 1996.
FIELD OF THE INVENTION
The invention relates generally to a fuel dispenser customer interface and, more particularly, to an display system for a fuel dispenser that presents graphical data to a customer.
BACKGROUND OF THE INVENTION
Dispensers for gasoline and other fuels are undergoing many advances in technology. For example, modern dispensers are electrically connected to computing devices that enable a customer to pay for the fuel at the dispenser itself. To receive a payment from the customer, many modern fuel dispensers utilize a credit/debit card device that includes a card reader, a keypad, and a small, inexpensive liquid crystal display that readily displays numerals and a limited amount of text.
The small display associated with a credit/debit card device are ideally suited to display messages such as "INSERT CARD" and "REMOVE CARD QUICKLY" to assist the customer in using the card reader. These messages are effective because the display is located near the card reader, and the instructions for operating the card reader are relatively simple. Furthermore, when not being used to operate the card reader, these displays can display short textual messages such as "GOOD MORNING".
However, once the payment has been received, the short textual messages are only modestly effective in communicating with the customer due to several drawbacks. For one, the messages are generic for use throughout the day and night. Therefore, the "GOOD MORNING" message described above is inappropriate for much of the day. In addition, the messages are not easily modified by a typical store clerk. Most store clerks have access to a computing device, such as a point-of-sale ("POS") controller, for controlling the dispenser. However, the expertise required to use the POS controller to change the messages appearing on the display is relatively high. Therefore, the "GOOD MORNING" message described above can not be simply converted to "GOOD AFTERNOON" at an appropriate time.
Another drawback with the display is that the messages shown thereon are relatively boring and unprofessional-looking. The "look" of a display is important because it needs to keep the customer's attention in order to be effective. An alternative to this drawback is to provide video display units with the fuel dispenser to display full motion video and graphic commercials. However, this solution is too expensive for many applications. Furthermore, this solution does not solve the generic-ness and difficulty in modification drawbacks discussed above.
Therefore, what is needed is a graphics interface that provides some level of control over the timing of the messages.
Furthermore, what is needed is a graphics interface that allows individual stores to easily modify and rearrange the messages.
Furthermore, what is needed is a graphics interface that provides interesting and professional-looking messages, without being too expensive.
SUMMARY OF THE INVENTION
The foregoing problems are solved and a technical advance is achieved by a graphics display system for a fuel dispenser that is responsive to segments of time, or dayparts, and also shows both pre-made, professional-looking advertisements, as well as locally made text messages.
To this end, the graphics display system utilizes the display terminal associated with a card reader device, a display controller with memory, a customer activated terminal ("CAT"), and a point-of-sale ("POS") controller. The system receives graphic frames from a personal computer as well as the POS controller. The system then arranges the graphic frames into chains that are appropriate to the specific day parts. The system also allows individuals to arrange, insert and delete graphic frames from the chains, thereby making the chains more appropriate for each fuel dispenser as well as each daypart.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a fuel dispensing system embodying features of the present invention.
FIG. 2 is a data flow diagram of the fuel dispensing system of FIG. 1 for utilizing the present invention.
FIGS. 3-6 are illustrations of exemplary graphic frames for use in the fuel dispensing system of FIG. 1.
FIG. 7 is a flow chart describing the operation of the fuel dispensing system of FIG. 1 in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, the reference numeral 10 refers to a fuel dispensing system embodying features of the present invention. The fuel dispensing system 10 includes a fuel dispenser 11, which contains many elements of a conventional fuel dispenser, such as a fuel nozzle 12 connected to a fuel supply (not shown). The fuel nozzle 12 may also be representative of multiple fuel nozzles, all connected to the fuel dispenser 11. The dispenser 11 has a front side 14 and a back side 16. In the following description of the preferred embodiment, only the front side 14 will be discussed for ease of description. However, the features of the present invention may also be applied on the back side 16, thereby allowing the dispenser to be operated by two customers at the same time.
The front side 14 houses a conventional credit card device 18, and a price board display 20. The price board display 20 comprises a large, conventional, active matrix flat panel display for showing conventional sales data such as total price ("$"), gallons dispensed ("gals."), and price per gallon ("PPG"). The credit card device 18 includes a keypad 22, a graphics display 24, and a card reader 26.
In addition to the dispenser 11, the fuel dispensing system 10 includes a computing center 30. In the preferred embodiment, the computing center 30 is remotely located inside a store (not shown) where it may be readily accessed. The computing center 30 comprises a point-of-sale ("POS") controller 34 and a removable, personal computer ("PC") 36. The POS controller 34 is permanently attached to the fuel dispenser 11, but the PC 36 is selectively connected and used, as described in greater detail with reference to FIG. 2.
It is understood that the PC 36 is a conventional personal computer capable of communicating with the POS controller 34. Also, the POS controller 34 is a conventional dispenser controller capable of controlling the conventional aspects of the dispenser 11, including the fuel nozzle 12 and the credit card device 18.
FIG. 2 illustrates a data flow for the present invention. It is understood that the fuel dispensing system 10 may be installed at a fuel station as an integrated system of new components or as an upgrade to existing equipment. Furthermore, many of the components described herein are conventional, it being understood that those of ordinary skill in the art can implement such components in the manner described herein.
The PC 36 is used primarily to receive, edit and/or create a plurality of graphic frames. Graphic frames are image files that display a limited amount of textual and graphic data, as discussed further with respect to FIGS. 3-6. The PC 36 may receive the graphic frames through many different types of data input 32. For example, a scanner 38 may be used to scan-in drawings and convert them to a readable format. Alternatively, a computer aided design ("CAD") program 40 may be used to draw the graphic frames on the PC 36 itself.
The PC 36 is connected to the POS controller 34 through an RS232 bus 42. In this way, the PC 36 can transfer the graphic frames to the POS controller 34, and then be quickly disconnected therefrom by removing the bus 42. Alternatively, the graphic frames can be transferred by a floppy disk 44 or by other means well known in the art.
The POS controller 34 includes a display 46, a keyboard 48, touchscreen or similar input device and a memory storage device 50 for performing conventional point-of-sale operations for the fuel dispenser 11. The POS controller 34 also receives the graphic frames from the PC 36 and stores them in the memory storage device 50. The POS controller 34 has a limited capability of creating its own graphic frames. Furthermore, the POS controller is used to define a series of control commands, discussed in greater detail below.
The POS controller 34 is conventionally connected to and communicating with a customer-activated terminal ("CAT") 52 through an RS485 or similar serial communication bus 54, thereby providing the main interface between the computing center 30 and the dispenser 11. A single CAT 52 is used by the dispenser 11 to control a customer interface for both sides 14, 16 of the dispenser. Communications between the POS controller 34 and the CAT 52 include conventional dispenser data that is well understood by those of ordinary skill in the art. The present invention, however, utilizes the bus 54 at times when activity on the bus is low, or idle, to update the CAT 52 with the graphic frames and control commands from the POS controller 34.
The CAT 52 then transfers the graphic frames and control commands to a display controller 56 through a bus 58. The display controller 56 utilizes the frames and commands, along with data stored in a read-only memory ("ROM") 60 and a random access memory ("RAM") 62 for controlling the graphics display 20. In the preferred embodiment, there are two display controllers, two RAMs and two ROMs, one for each side 14, 16 of the dispenser 11. The graphic frames and control commands are arranged into "scenes". Scenes are a series of graphic frames that display an instructional or commercial message. The display controller 56 drives the scenes onto the graphics display 20 as described below.
Referring to FIG. 3, a scene 70 is defined by graphic frames 70a, 70b, 70c, 70d, 70e, and 70f. The scene 70 is used to give instructions on how to operate the fuel nozzle 12 (FIG. 1). Because scene 70 will be used frequently, it is permanently stored in the ROM 60.
Referring to FIG. 4, a scene 72 is defined by graphic frames 72a, 72b, 72c, and 72d. The scene 72 extends a seasonal message. Because scene 72 will only be used at certain times of the year, it is temporarily stored in the RAM 62.
Referring to FIG. 5, a scene 74 is defined by graphic frames 74a, 74b, 74c, and 74d. The scene 74 is used to advertise ice. Because scene 74 will be used at certain times of the day or year, it is temporarily stored in the RAM 62.
Referring to FIG. 6, a scene 76 is defined by graphic frames 76a, 76b, 76c, and 76d. The scene 76 is used to advertise a lottery ticket. Although scene 76 will be frequently displayed, it is subject to frequent changes and therefore, it is temporarily stored in the RAM 62.
Although not shown, one or more graphic frames consisting of textual messages can be generated from the POS controller 34. For example, in scene 74, a new graphic frame can be inserted after frame 74d that displays a message such as "ONE BAG COSTS 99¢". This message can be created by using the keyboard 48 of the POS controller 34 to type in the message, and using a simple subroutine (not shown) to convert the message into a graphic frame.
The scenes 70, 72, 74, 76 are controlled by the control commands. The control commands are subdivided into two components: dayparts, and advertisement chains (Ad Chains).
The dayparts component subdivides a day into one or more time slots. For example, referring to Table 1 below, a time slot 1 represents a time period from 5:00 a.m. to 10:30 a.m., a time slot 2 represents a time period from 10:30 a.m. to 9:00 p.m., and a time slot 3 represents a time period from 9:00 p.m. to 5:00 a.m. In this way, the scenes that are appropriate for different times of the day can be shown only in specific dayparts. For example, the ice scene 74 can be shown only during Time Slot 2.
TABLE 1______________________________________Time Slot 1 Enable/Disable = Enable Start Time = 5:00 AM End Time = 10:30 AM Ad Chain = 5Time Slot 2 Enable/Disable = Enable Start Time = 10:30 AM End Time = 9:00 PM Ad Chain = 6Time Slot 3 Enable/Disable = Enable Start Time = 9:00 PM End Time = 5:00 AM Ad Chain = 7______________________________________
The Ad Chain component is a data file used with one or more dayparts to orderly display the desired scenes for each daypart (see Table 1). For example, referring to Table 2 below, an Ad Chain 5 is used to describe a sequence that displays each of the scenes 70 and 72. Each graphic frame of the scenes includes a frame sequence number, a filename, a duration representing an amount of time each frame will be displayed, a brief description of the frame, and a storage location for the frame (ROM 60 or RAM 62). Although the scenes are shown in a particular order, e.g. 72a, 72b, 72c, 72d, the Ad Chain can be modified to rearrange the order of the scenes, or to insert different frames between the scenes.
TABLE 2______________________________________Ad Chain 5:Frame Duration StorageNo. Filename (0.1 sec.) Description Location______________________________________1 nozzle1.img 10 Remove Nozzle (70a) ROM (60)2 nozzle2.img 10 Remove Nozzle (70b) ROM (60)3 nozzle3.img 20 Remove Nozzle (70c) ROM (60)4 nozzle4.img 10 Remove Nozzle (70d) ROM (60)5 nozzle5.img 10 Remove Nozzle (70e) ROM (60)6 nozzle6.img 20 Remove Nozzle (70f) ROM (60)7 blank1.img 4 Blank Screen ROM (60)8 easter1.img 10 Happy Easter (72a) RAM (62)9 easter2.img 10 Happy Easter (72b) RAM (62)10 easter3.img 10 Happy Easter (72c) RAM (62)11 easter4.img 30 Happy Easter (72d) RAM (62)______________________________________
Referring to FIG. 7, a routine 100 is utilized to display the graphic frames on the graphics display 24 (FIG. 2). In the preferred embodiment, processing of the routine 100 is shared between the PC 36, POS controller 34, the CAT 52 and the display controller 56. Execution begins at step 102, where the graphic frames are loaded from the PC 36 into the storage device of the POS controller 34. In the preferred embodiment, this step is performed by a utility program, running on the PC 36, that stores the frames into the storage device 50. At step 104, the dayparts are defined. This is executed by the POS controller 34, as described above with reference to Table 1. At step 106, the Ad Chain associated with each daypart is defined. This is also executed by the POS controller 34, as described above with reference to Table 2.
At step 110, a determination is made as to whether a new daypart is about to begin. This is done by comparing the start times for each Time Slot to a real time clock (not shown). If a new daypart is not about to begin, execution jumps to step 116, discussed below. If a new daypart is about to begin, execution proceeds to step 110, where the POS controller 34 sends the appropriate Ad Chain to the CAT 52. As determined by the Ad Chain, the CAT 52 stores certain graphic frames in the RAM 62. At step 114, the CAT 52 sends the control command data, such as sequence and duration, to the display controller 56.
At step 116, a determination is made as to whether the dispenser 11 is being used by a customer. If so, execution proceeds to step 118, where the display controller 56 sequences through the Ad Chain, displaying graphic frames according to the sequence and duration data. Upon completion of step 118, execution loops back to step 108. If at step 116, a determination is made that the dispenser 11 is not being used by a customer, execution loops back to step 108.
Although illustrative embodiments of the present invention have been shown and described, a latitude of modification, change and substitution is intended in the foregoing disclosure, and in certain instances, some features of the invention will be employed without a corresponding use of other features. For example, the dispenser may include a speaker so that a combination of sound files and graphic frames can provide a multimedia environment. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A graphics display system for a fuel dispenser that is responsive to segments of time, or dayparts, and also shows both pre-made, professional-looking advertisements, as well as locally made text messages. In a preferred embodiment, the graphics display system utilizes the display terminal associated with a card reader device, a display controller with memory, a customer activated terminal ("CAT"), and a point-of-sale ("POS") controller. The system receives graphic frames from a personal computer as well as the POS controller. The system then arranges the graphic frames into chains that are appropriate to the specific day parts. The system also allows individuals to control, insert and delete graphic frames into the chains, thereby making the chains more appropriate for each fuel dispenser as well as each daypart.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for making a medical glove whose fingers have thinner walls than the rest of the glove.
2. Description of the Related Art
Manufacturing surgical gloves involves a process that includes dipping a form fashioned to resemble the human hand into a solution of coagulant, drying the coagulant and then immersing the form into an elastomeric (e.g., latex) compound. After depositing the layer of latex compound on the form, the forms are usually rotated continuously until the coagulant reacts producing a gelled latex film. This rotation equalizes any wet latex runs and assures a more uniform overall gauge in the finished gloves. After the film is gelled, it is leached with water in order to remove any water soluble materials from the deposited film, dried, vulcanized and stripped from the glove form resulting in a finished glove. The above process involves dipping the glove form into a latex compound fingertips first; thus the fingertips are the last to be pulled out of the latex compound. Therefore, the fingertip gauge of the glove produced with the above process must be heavier than or equal to the cuff gauge. To prevent cuff tears during donning, the cuff gauge of a glove is generally at least 0.15 mm. Consequently, the fingertip gauge must be equal to or thicker than 0.15 mm. By these standards, current gloves are not suitable for delicate operations, such as those performed by ophthalmologists, due to poor touch sensitivity. Various methods have been proposed to produce gloves in which the fingertip gauge is thinner than the cuff gauge.
U.S. Pat. No. 2,097,528, issued on Nov. 2, 1937, to H. A. Morton, discloses a method of making rubber gloves in which a glove form is first immersed in a coagulant solution to provide a uniform coating over the form. The form is then dipped into a neutralizing agent, fingers first, to a depth that corresponds to the portion of the glove on which a thinner deposit is desired. Neutralizing the coagulant reduces its effectiveness; thus, when the form is subsequently submerged in a latex dispersion, less latex is deposited on the neutralized coagulant and the resultant glove is thinner there. A similar result is achieved in a process in which the form is dipped in a latex solution two (or more) times, with a portion of the form being dipped into a neutralizing solution between latex immersions.
U.S. Pat. No. 3,397,265, issued on Aug. 13, 1968, to H. N. Ansell, discloses a process in which a glove form that is coated with a concentrated coagulant is immersed in a solvent for the coagulant to a depth that corresponds to the portion of the form on which a thin latex coating is ultimately desired. After removing the coagulant coating from that portion of the form, the form is dipped into a dilute coagulant, so that the dilute coagulant covers the portion of the form from which the concentrated coagulant had been removed. Finally, the form is immersed in a latex solution. More latex deposits on the portion of the form that is coated with concentrated coagulant than on the portion coated with dilute coagulant. Consequently, the resultant glove is thicker in the region of the cuff than in the fingers.
U.S. Pat. No. 3,859,410, issued on Jan. 7, 1975, to H. Sidley, discloses a method of reproducing a glove having relatively thin wall thickness in the finger and palm portions and thicker wall thickness in the cuff region by first spraying concentrated coagulant onto the cuff region of a form and dilute coagulant onto the fingers and palm. The form is then dipped in a latex solution, where a thicker latex coating deposits on the region coated with concentrated coagulant.
Each of the procedures of the prior art permit the fabrication of gloves having less thickness in the fingers than the cuff, but they involve the use of corrosive solvents and/or are unsuited for fabricating gloves having fingers of extremely thin (thickness <0.13 mm) wall thickness.
SUMMARY OF THE INVENTION
In accordance with the present invention, a process for making a medical glove comprises the steps of
a) dip-coating onto a glove form a layer of coagulant that comprises an ionic metal salt,
b) dip-coating over at least a part of the coagulant layer a layer of a first elastomer,
c) immersing a first portion of the coated form into a solvent for the metallic ions of the metal salt to remove substantially all the metallic ions in the layers,
d) dip coating a layer of a second elastomer over the first elastomeric layer, whereby the resultant elastomer coating is thinner on the first portion of the form than on the remainder of the coated form, and
e) removing the coating from the form.
The process of the invention permits the fabrication of gloves having finger wall thickness of less than 0.13 mm, which makes these gloves well suited for ophthalmology, and other areas where the wearer of the glove must maintain maximum finger sensitivity. For brevity, we refer to gloves whose fingers have thinner walls than do their cuffs as "thin-fingered" gloves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a cross section of a tank with a glove form being coated over its "full" length.
FIG. 2 depicts the glove forms of FIG. 1 being dipped partially into the tank of FIG. 1.
FIG. 3 depicts the glove form of FIG. 1 being dipped partially into the tank of FIG. 1, to a different depth than is shown in FIG. 2.
FIG. 4 depicts a finished glove.
FIG. 5 is an enlarged cross section of part of the glove of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for fabricating medical gloves that have fingers whose wall thickness is very small. Medical professionals require thin-fingered gloves of that type in a number of medical situations, including ophthalmology and other exacting disciplines, in which only the minimum interference with the sensitivity of the bare hands can be tolerated. At the same time, these gloves must have sufficient strength--i.e., wall thickness--outside the finger area to permit the gloves to be donned and used conveniently and without significant risk of tearing. Since gloves are generally fabricated by dipping hand-shaped forms, fingers first, into a solution or dispersion of an elastomer. That fabrication procedure tends to yield gloves whose fingers have greater wall thickness than the rest of the glove, since the fingers of the form spend the longest time in the elastomer.
FIG. 1 illustrates part of an apparatus for practicing the present process. It is of a type that has long been used for making elastomeric gloves and includes a glove form 10, which generally has the shape of a hand, and a tank 12 into which the form is dipped. The complete apparatus includes a series of tanks, each similar to tank 12, into which the form is dipped successively. Of course, the liquid 14 would be different in the different tanks. For dipping purposes, the form 10, the tank 12, or both may be moved. When all the dipping steps are completed, a finished glove is removed, or "stripped", from the form and reversed so that the first layer is on the outside. The form 10 is generally made of glazed or bisque porcelain or plastic. Of course, the size of the form determines the size of the glove.
A variety of elastomers may be used for medical gloves, including natural rubber latex, nitrile rubber latex, coagulable polyurethane aqueous dispersion, and the like. In the present invention, the gloves are formed of two layers of elastomers, which may be different. A glove in which both layers are natural rubber latex is preferred, because it has superior properties and lower cost. For brevity and convenience, we will describe the process of this invention in the context of natural rubber latex gloves, recognizing that the modifications necessary to produce gloves of other common materials will be clear to the artisan. Conventional methods for preparing rubber latex gloves are described in a bulletin "Dipping With Natural Rubber Latex"; The Malaysian Rubber Producers' Research Association; Hertford, England, 1980, and the disclosure of that bulletin is incorporated herein by reference.
As was stated above, the conventional glove-manufacturing process yields gloves whose fingers have a greater wall thickness than their cuffs. To overcome this tendency and to provide gloves with thin fingers, the process of the present invention involves coagulant and multiple latex dips of a glove form, and extracting metallic ions--preferably, bivalent metallic ions--off the finger and thumb portions of the latex-coated glove form. The latex deposition rate on the area from which metallic ions have been extracted is substantially reduced during the second latex dip.
Glove forms are preferably heated to about 65°-75° C. before coating, in order to evaporate off any alcohol or water that may remain on the surface from a wash cycle. In order to provide reproducible latex layers on the form, a coagulant layer is first dipped onto the form. The coagulant may be of any composition well known in the art and described in the above-mentioned bulletin, such as aqueous or alcoholic solutions of calcium, or other metal, salts. The coagulant comprises a mold release agent, which facilitates removal of the finished glove from the form, and a bivalent metal salt, which causes a latex overcoat to gel. A preferred mold release agent and metallic salt are calcium carbonate and calcium nitrate, respectively.
The first latex dip determines the minimum wall thickness of the glove fingers. That thickness is less if the form is immersed in the latex for a shorter period of time, which, in turn, can be accomplished by limiting the first latex dip to a portion of the coagulant-coated glove form. The depth of the first latex dip may be at any position of the glove form. As shown in FIG. 2, however, the preferred depth of the first latex dip is just above the thumb crotch of the glove form. The first latex dip is a latex dispersion comprising elastomeric material(s), stabilizer(s), an antioxidant, an activator, a vulcanizer and accelerator(s). Preferably, the latex dispersion has lower solids percentage than is used for conventional glove production to facilitate achieving a thin coating. An alternative way of obtaining a thin coating with the first latex dip is to dip the bare glove mold in latex and to follow with the coagulant dip. That procedure is less preferred, however, because the finished glove, lacking the mold release agent in the first coating, is hard to strip from the mold.
In a coagulation dipping process, the film thickness deposited on a glove form increases with the metal ion concentration and the time the glove form spends immersed in the latex compound. Thus, latex deposition in the second dip is reduced on a portion of the coating by removing from that portion the metal ions, which diffuse from the coagulant layer to the surface of the latex deposited in the first dip. Metal ions are extracted from the coagulant latex deposit with water, alcohol, or a mixture of both. The preferred metal ion solvent is water. The temperature of the water is not critical and can be from as low as near the freezing point to near the boiling point, but room temperature or above is preferred; e.g., 68° F. (20° C.) to 150° F. (65° C.). The depth of the metal ion solvent determines the portion of the glove that will have thin walls and should not be greater than the depth of the first latex dip. The preferred depth is just above the finger crotches, as is illustrated in FIG. 3.
The amount of metallic ions extracted depends upon the concentration of metallic ions in the latex gel, salt content and temperature of the water, and time of contact with the water. Generally, the period of contact will be between a few seconds and 30 minutes, preferably a minute or two. While the contact time can be up to an hour or more, the extraction efficiency decreases markedly after about a half hour.
The second latex dip is applied to the full length of the glove form (as shown in FIG. 1). The latex formulation for the second latex dip can be the same as or different from the first latex dip. It is preferred that the second latex dip be a layer which can supply bulk, softness, strength and other physical properties to the glove. Based on these conditions, a natural rubber latex is a preferred material.
The process described above produces a thin-fingered glove (as defined earlier). FIG. 4 depicts the appearance of a finished glove. FIG. 5 depicts an enlarged cross section of a glove of the invention showing both the "thick" and "thin" regions. Wall thickness in the (thin) fingers is preferably less than about 0.13 mm.
For a better understanding of the present invention, the following examples illustrate various processes for producing thin-fingered gloves. The examples are not intended to be in any way limiting.
EXAMPLE I
A glove form having the general contour of a human hand is first heated in an oven. Then:
1. The heated glove form is dipped full length in a coagulant that comprises 20% calcium nitrate, 6% calcium carbonate and 0.5% wetting agent in an alcoholic solution.
2. A latex dip is applied up to just above the thumb crotch of the coagulant-coated glove form. The rubber compound for the first latex dip is a natural rubber latex compound having 28% solids.
3. The thumb and finger portions of the latex-coated glove form is immersed in a water bath at 126° F. (52° C.) for 1.5 minutes to extract calcium ions from the latex deposit. (Latex deposition on the portion immersed inside the hot water will, therefore, be minimal during the second latex dip.)
4. Excess water droplets are dried in a 230° F. (110° C.) oven for 3 minutes.
5. A second latex dip is applied to the full length of the reheated glove form. The rubber compound for the second latex dip is a natural rubber latex compound having 33% solids.
After the second latex deposit is gelled, it is leached with water, dried, vulcanized and stripped from the glove form to provide the finished glove.
EXAMPLE II
A form is first heated in an oven. Then:
1. A latex dip is applied to the full length of the heated glove form. The rubber compound for the first latex dip is a nitrile or a natural rubber latex compound having 40% solids.
2. The latex coated glove form is dipped full length in a coagulant that comprises 20% calcium nitrate and 0.5% wetting agent in an alcoholic solution.
3. The coagulant is washed off the thumb and finger portions of the coagulant coated glove form with the water at 126° F. (52° C.) for 1.5 minutes.
4. Excess water droplets are dried in a 230° F. oven for 3 minutes.
5. A second latex dip is applied to the full length of the reheated glove form. The rubber compound for the second latex dip is a natural rubber latex compound having 33% solids.
After the latex deposit is gelled, it is leached with water, dried, vulcanized and stripped from the glove form to provide the finished glove.
EXAMPLE III
In accordance with the general procedure of EXAMPLE II, a glove is formed utilizing NeoRex R-967, a polyurethane aqueous dispersion, for the first latex dip.
It is found that the finger gauge is less than the cuff gauge for gloves produced in accordance with EXAMPLE I, II or III.
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A process for making medical gloves whose fingers have thinner walls than the rest of the gloves involves first depositing onto a hand-shaped glove form a layer of coagulant that comprises an ionic metal salt, then depositing an elastomeric layer. Part of the coated form is then leeched of metal ions in the coating, and the form is overcoated with a second elastomeric layer. The overcoated layer is thinner in the part where it overlies the leeched coating. The gloves find particular usefulness in delicate operations such as those performed by ophthalmologists.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing structural elements, preferably prototypes, in which a “lost” model, i.e., a positive model, of the structural element is produced in a first step, the model is subsequently cast with a molding compound for producing a mold, i.e., a negative model, and the mold then produces the structural element, preferably a prototype, by casting.
2. The Prior Art
Processes of this type, which are preferably employed for producing costly prototypes containing, for example complex cavities, are known from the state of the art. The plaster casting process, in which the molding compound is a gypsum compound, is such a process. In some applications, the so-called “fine casting process” is employed for producing such prototypes instead of using the plaster casting method. The drawback common to these two processes is that they are either not suitable at all for producing prototypes with complex shapes and/or complex cavities, or that they are very expensive.
A process for producing structural elements such as prototypes has become known from German Patent No. DE 195 45 167 A1. This process uses a polystyrene model, which is coated with wax by immersing it in liquid wax. A ceramic sludge is then applied to the surface of the wax. The model is then calcinated and the cavity formed by gassing out the polystyrene is filled by pouring in the molding compound using the fine casting process. In order to permit the manufacture of more complex structural elements by this method, several pieces of the structural elements are first produced in this process, which then have to be assembled into a complete structural element following their immersion in wax. This process is relatively complicated and thus costly, because several components of the structural element have to produced separately.
SUMMARY OF THE INVENTION
It is therefore an object of the invention is to provide a process for producing structural elements, in particular prototypes of the type specified above, that permits the structural element to be manufactured with less technical expenditure and at a consistent rate, as well as less expensively.
These and other objects of the invention are accomplished by process for producing structural elements comprising producing a positive model of the structural element in a first step, casting the positive model with a molding compound to produce a negative mold, and manufacturing the structural element by casting the mold.
The model is cast with the molding compound in a number of successive steps, and the arrangement or position of the model is changed relative to a reference plane in each of the individual steps of casting or filling.
The main problem afflicting the prior methods is that reproduction of complex cavities with molding compound is not possible, because air cannot completely escape from these cavities when they are filled with the molding compound. The present invention overcomes this problem in the following manner: In a first part step of the process, the model is first cast with the molding compound and the cavities are filled to the extent possible with the molding compound while the model is in a first arrangement or position relative to the reference plane. In this first step, lateral openings of the model, if any, are closed so that the molding compound cannot exit through these openings. The molding compound is subsequently poured in through openings from the top. The position of the model relative to the reference plane is then changed, for example, turned by 90° about one of its axes. Molding compound is then again filled in through a top opening of the model, and lateral openings of the model, if any, are closed. Since the position of the model was changed, air now can escape from parts of the cavity from which no escape was possible in the previous arrangement of the model. Thereafter, in another step of the process, the position of the model relative to the reference plane is changed again, if need be, and any lateral openings are closed. Molding compound is then filled in again through an opening now disposed at the top.
If, for example, the model is turned by 90° after each of these steps, and all three spatial axes are taken into account, all cavities of the model can be filled with molding compound. A maximum of six different arrangements of the model and, correspondingly, six steps, depending on the structure of the model and the complexity of the cavities are needed to file the model. The model can therefore be completely reproduced.
Even though the process for casting the model with the molding compounds is divided into individual steps, the process as defined by the invention offers the advantage that the model does not have to be divided, and the process can always be carried out with a single-piece model. The process as defined by the invention, furthermore, can be carried out smoothly at a relatively consistent rate.
When certain molding compounds are employed with the process according to the invention, i.e., materials such as plaster which set and cure relatively quickly, it may be advantageous if connecting elements with a suitable geometry are employed. These elements are jointly cast in the molding compound in the respective step of the process. After the molding compound poured in one step has set and cured at the start of the next-following step, bonding of the fresh molding compound to the molding compound already set is enhanced by the connecting elements. Connecting elements with undercut surfaces are preferably employed, so that a positive joint of the individual surfaces of the molding compound is obtained after curing is completed. For example, simple available metal elements such as screws or the like can be used as connecting elements, and do not add additional significant cost to the process.
If the model contains defined cavities, for example relatively long channels which are filled with the molding compound, a reinforcement is preferably incorporated in the regions of the molding compound filling the channels in order to prevent cured parts of the molding compound, e.g., longer arms of filling channels, from breaking off or becoming damaged after the model has been removed. Suitable elements such as wires or other metal parts consisting of flat steel, round steel or the like can be employed for such reinforcement.
It is most preferable that in each step of casting of the model with the molding compound, the model is set up in as favorable a spatial position as possible, so that the fewest individual steps of the casting process is needed depending on the complexity of the cavities present.
Additional advantages of the invention are shown by the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 is a schematically simplified sectional drawing of a model, which is filled with a plaster compound according to the process defined by the invention;
FIG. 2 is a correspondingly schematically simplified representation of the model of FIG. 1 shown, however, in an arrangement turned clockwise by 90°;
FIG. 3 is an enlarged detail view of a cutout III from FIG. 2 shown in another position;
FIG. 4 is another schematically simplified view of the finished mold resulting from the model of FIG. 1;
FIG. 5 is a schematically simplified sectional drawing of a model filled according to the process as defined by the invention, according to an alternative embodiment;
FIG. 6 is another view of the model shown in FIG. 5, rotated by 180°; and
FIG. 7 is another view of the model according to FIGS. 5 and 6 shown in another phase of the process as defined by the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is made first to FIG. 1 . This representation shows a model 10 for producing a prototype consisting of sintered polystyrene. In the representation according to FIG. 1, model 10 is shown in a schematically highly simplified way in order to explain the process. The cavity of model 10 is filled with a molding compound, such as a plaster compound 11 . When the process as defined by the invention is employed in practical life, the models are generally substantially more complex with respect to their outer shape and their cavities. However, the process as defined by the invention is carried out in the same way as explained below.
Model 10 according to FIG. 1 consists of a bottom 10 a, a vertical side wall 10 b adjoining bottom 10 a on the left, and a vertical side wall 10 c adjoining bottom 10 a on the right. Model 10 has a top wall 10 d, which extends only partially over the width of the model and parallel to bottom 10 a. Starting from the left side wall 10 b, a partial wall 10 e extends from the top end at an acute angle inwardly in the direction of the cavity and inclined downwardly. A molded-on, inclined partial wall 10 f extends from the upper wall 10 d from the inner end of upper wall 10 d at an acute angle downwardly and in the direction of the right-hand side wall 10 c.
If a model 10 according to FIG. 1 were filled with plaster compound 11 from the top through the top opening 13 , residual air would collect or be trapped in cavity 12 a on the left, and the cavity 12 b on the right, and could not completely escape. This means that the cavity cannot be completely filled with plaster compound 11 from the top through opening 13 .
To fill the cavities of model 10 with plaster compound 11 , model 10 is turned by 180° in the plane of the drawing, i.e., it is turned upside down to a position as shown in FIG. 2 . It is now possible to first fill the cavity in the interior of model 10 with plaster compound 11 , in such a way that the plaster compound 11 a, 11 b is first filled in via a hose or a similar feed line through the then-downwardly open opening 13 . The plaster compound 11 a, 11 b is only filled up to a level such that the cavities 12 a and 12 b are filled, but each only up to the top edge of the two inclined partial walls 10 e and 10 f. Plaster compound 11 a, 11 b thus cannot exit again downwardly from the two cavities 12 a, 12 b via opening 13 . The main part of the hollow space or cavity disposed further up is not yet filled with plaster compound 11 , but filled only thereafter in a second process step.
It is possible that plaster compound 11 a, 11 b will set and cure relatively quickly after the first process step. It may then be difficult to tie or bond the plaster compound 11 to be filled in the second process step to the boundary surface of the “old” or cured plaster compound. For this reason, connecting elements 15 are used, which are embedded in the soft plaster compound in the first pouring step, so that these elements project beyond the boundary surface into the cavity as shown in FIG. 2 . In the next step, fresh plaster compound 11 can then be filled into the remaining hollow space of model 10 to obtain a positive connection with the connecting element 15 , so that the fresh plaster compound 11 is bonded well to the cured plaster compound 11 a, 11 b, as shown in FIG. 3 .
After connecting elements 15 have been embedded in plaster compound, 11 a, model 10 is turned from the position shown in FIG. 2 again by 180° in the plane of the drawing, so that model 10 assumes again the starting position as shown in FIG. 3 . Cavities 12 a, 12 b, which would otherwise be difficult to fill, already contain plaster compound 11 a as shown. Now, fresh plaster compound 11 can be filled in from the top through opening 13 , and the entire remaining cavity of model 10 can be filled with fresh plaster compound. No air inclusions remain in this process in the cavities of model 10 .
Model 10 , which is now completely filled in the interior cavity with plaster compound 11 , 11 a, 11 b, is subsequently set up in a container containing additional fresh plaster compound, and is then completely coated with plaster compound 11 c on the outside, as shown in FIG. 4 . After this process, model 10 is completely reproduced by plaster compound 11 , 11 a, 11 b both in its complex inner contour and its outer contour. Model 10 , which consists of plastic such as sintered polystyrene, can be removed by burning it out or by other methods. One obtains in this way the plaster mold which represents the negative for the manufacture of the prototype to be produced. A metal such as aluminum is subsequently poured into the mold, and the structural element is reproduced, so that the shape of the structural element corresponds to model 10 . The cured plaster compound 11 , 11 a, 11 b, 11 c, which is present on the outside around the structural element and, of course, in the cavities of the structural element, is removed mechanically.
Connecting element 15 is shown enlarged in FIG. 3 . It is possible to use screws with nuts as connecting elements 15 , or any other elements which preferably have undercut surfaces. As can be seen in the figure, the shaft 15 a of connecting element 15 is partially embedded in plaster compound 11 a, which has already set. However, a piece of shaft 15 a projects into the first still-unfilled cavity, as does nut 16 . The underside of head 15 b has undercut surfaces 15 c. As a result of the anchor-like shape of screw head 15 b with the undercut surfaces 15 c and due to the shape of nut 16 , a good bond of the fresh plaster compound 11 to the set plaster compound 11 a is obtained after the fresh plaster has been filled in. The shape of connecting elements 15 is selected rather randomly in the exemplified embodiment according to FIG. 3 . These connecting elements may also have heads with the shape of a dovetail, or grooves, a serration, a toothing or the like.
Another embodiment of the invention is shown in FIGS. 5 to 7 . FIG. 5 shows a schematic sectional representation of another model 20 , which is filled in a number of steps according to the process as defined by the invention. Model 20 has a plurality of cavities, which are arranged so that the model cannot be completely filled in one process step. Therefore, the following procedure is employed: In its position shown in FIG. 5, model 20 is first filled with a plaster compound 11 a in the cavity shown at the top. Again, a connecting element 15 can be incorporated in the plaster compound 11 a in order to enhance bonding to additional plaster compound filled in a subsequent process step. As can be seen in FIG. 5, the lower cavity 12 b initially remains unfilled. Model 20 is now turned in the plane of the drawing by 180°, so that it is moved into the position shown in FIG. 6 . The cavity filled with plaster compound 11 a is now disposed at the bottom. Cavity 12 b, which is now disposed at the top, is then filled with a plaster compound 11 b in a next step, so that the condition shown in FIG. 6 is reached. A connecting element 15 is again embedded in plaster compound 11 b in order to facilitate bonding to an additional plaster compound.
Reference is now made in the following to FIG. 7 . Based on the representation according to FIG. 6, model 20 is turned by 90° counterclockwise in the plane of the drawing and is then placed in container 21 containing additional plaster compound 11 c. Following curing of plaster compound 11 c, model 20 can be removed, for example by burning it out, so that a plaster mold is then obtained that has cavities corresponding with the shape of the earlier model 20 . A metal is again poured into the plaster mold and a structural element is obtained with a shape conforming to the one of model 20 . Again, plaster compound 11 a, 11 b, 11 c can be removed mechanically.
Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
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A process for producing structural elements, preferably prototypes, in which a “lost” model, i.e., positive model, of the structural element is produced in a first step and the model is subsequently cast with a molding compound to produce a negative mold. The mold is then used for manufacturing the structural element, preferably a prototype, by casting. The model is cast and/or filled with the molding compound in a plurality of successive steps and the position of the model relative to a reference plane is changed in each of the individual steps of casting or filling.
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RELATED APPLICATIONS
[0001] The present application claims benefit of U.S. Provisional Application No. 61/771,709, filed on Mar. 1, 2013, which is hereby incorporated by reference as if set forth in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to air handling systems, and more specifically to a tool-less auto-aligning filter retention system that releasably retains a filter cartridge in an operable position within air supply and air exhaust systems.
BACKGROUND OF THE INVENTION
[0003] Filters used in clean room environments are difficult and time consuming to change, and often cause the clean room environment to be contaminated during the changing process.
SUMMARY OF THE INVENTION
[0004] A filter retention system for releasably retaining a filter cartridge in an operable position within air supply and air exhaust systems is comprised of a filter cartridge, filter retainers, mounting frame with integral sealing knife edge and filter alignment brackets. The filter retainers allow for installation and removal of the filter cartridge without the use of tools. The retention system automatically aligns filter cartridges such that an airtight seal is created between the sealant containing groove in the filter cartridge and the sealing knife edge of the retention system.
[0005] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0006] Aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, and in which:
[0007] FIG. 1 is a diagram of filter retention system in accordance with an exemplary embodiment of the present disclosure;
[0008] FIG. 2 is a perspective view of a filter retainer clip in accordance with an exemplary embodiment of the present disclosure;
[0009] FIG. 3 is a side view of a filter retainer clip in accordance with an exemplary embodiment of the present disclosure;
[0010] FIG. 4 is a plan view of a filter cartridge installed in a system mounting frame, in accordance with an exemplary embodiment of the present disclosure;
[0011] FIG. 5 is a sectional view taken of a filter cartridge, in accordance with an exemplary embodiment of the present disclosure;
[0012] FIG. 6 is a sectional view taken of a filter cartridge, in accordance with an exemplary embodiment of the present disclosure;
[0013] FIG. 7 is a perspective view of a filter alignment bracket, in accordance with an exemplary embodiment of the present disclosure;
[0014] FIG. 8 is a side view of a filter alignment bracket, in accordance with an exemplary embodiment of the present disclosure;
[0015] FIG. 9 is a detail view of an installed filter cartridge in accordance with an exemplary embodiment of the present disclosure;
[0016] FIG. 10 is a perspective view of an air distribution device incorporating a filter retention system in accordance with an exemplary embodiment of the present disclosure;
[0017] FIG. 11 is an exploded view of an air distribution device in accordance with an exemplary embodiment of the present disclosure;
[0018] FIG. 12 is a section view of an air distribution device, in accordance with an exemplary embodiment of the present disclosure;
[0019] FIG. 13 is a section view of an air distribution device in exhaust operation, in accordance with an exemplary embodiment of the present disclosure;
[0020] FIG. 14 is a perspective view of a filter retainer clip installed in a filter retention system, in accordance with an exemplary embodiment of the present disclosure; and
[0021] FIG. 15 is a perspective view of multiple filter retention systems installed within a single sealed plenum, in accordance with an exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures might not be to scale and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness.
[0023] The present disclosure relates to a filter alignment and retention system for installing filter cartridges that have a sealant containment groove which can be used in systems with a sealing knife edge or in other suitable applications. Such filters can be used in many different applications for contamination control, such as in manufacturing clean rooms, medical operating rooms, medical diagnostic rooms, medical treatment suites, pharmacies, and in other locations where it is necessary to control contamination. The filter cartridges used in these applications remove particulates from the air at a predetermined efficiency for a specified minimum particle size.
[0024] The United States National Institutes of Health (NIH) and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) have conducted research in medical operation suites that has shown that a properly designed laminar flow ventilation system can reduce the number of airborne particles that come in contact with a surgical site. This research further establishes that a correlation exists between the number of airborne particles and the rate of surgical site infections. NIH and ASHRAE have set forth design requirements for such systems, including minimum filtration requirements, supply diffuser type, minimum area of laminar flow coverage, return/exhaust location, air change rate, and room air temperature. In many installations, the laminar flow diffusers have high efficiency particulate air (HEPA) or ultra-low penetration air (UPLA) filter cartridges installed to fulfill the requirements of these designs.
[0025] In clean rooms and other contamination-controlled facilities, the number of particles per cubic foot of a specific size determines the contamination level. The maximum quantity and particle size are specified in ISO standards. The contamination level is generally proportional to the number of air changes per hour. As the air change rate increases the room becomes “cleaner,” and requires a larger quantity of filters.
[0026] In order to minimize contamination, filter cartridges should be installed in the supply air diffusers, the ceiling grid system (when a supply plenum is used), or in the return/exhaust air grille. This arrangement prevents contamination from the ductwork from entering into the room, and prevents contamination of the ductwork that is downstream from a filtered exhaust grille.
[0027] When in operation, particulates will be captured and retained by the media of the filter cartridges, which increases the pressure drop across the filter cartridge. The period of useful operation for a filter cartridge is not fixed, and is instead typically determined by when the pressure drop across the filter reaches a predetermined maximum allowable pressure drop, although it can also be based on predetermined maximum time in use, a predetermined number of procedures/processes that have been completed in the space, or other suitable metrics that have some correlation to an increase in pressure drop. Once a filter cartridge has reached the maximum pressure drop or other suitable limit set for useful operation, it must be replaced.
[0028] Clean rooms and other contamination-controlled facilities will typically have a significant quantity of filter cartridges installed to meet the required regulations and standards for their operation. Typically, all filters in a given space require replacement at the same time. Replacing each filter cartridge typically involves removing a large number of brackets by extracting screw/nut type fasteners, replacing the filter, and then re-installing the brackets, which is a repetitive, time consuming process that requires multiple technicians to safely complete removal of the old filters and installation of the new filters. If the new filters are not aligned correctly, a proper seal (such as may be verified through testing in accordance with IEST recommended practices) will not be established between the knife edge and filter cartridge sealant, and the filter must be reinstalled or adjusted and retested, which can result in further delay.
[0029] Moreover, when the filter cartridge is released from the filter retention system, the “seal” between the room and the contaminated plenum/ductwork is broken. After a new filter cartridge is installed, the “seal” is restored, but the room has now been contaminated by air and particulates from the contaminated area. As a result, the entire room must be decontaminated before the room can be used again, which is a costly and time-consuming process. The longer that the filter changing process takes, the longer it will take to decontaminate the room.
[0030] Therefore, there is a need for a filter retention system that allows an old filter cartridge to be removed quickly and that can automatically align a new filter cartridge for proper installation, to reduce the man-hours and overall time required for replacement of the filter cartridges.
[0031] The present disclosure provides a filter retention system that allows an old filter cartridge to be quickly removed and a new filter cartridge to be quickly installed without the use of tools, while ensuring proper alignment of the filter cartridge sealant with the sealing knife edge. The filter retention system of the present disclosure can be used to remove contaminates from air that is supplied to a space or exhausted from a space. In the majority of applications, the filter retention system of the present disclosure can be used as a component of an air distribution device. These devices can include an opening to receive the filter retention system with the filter cartridge installed and an opening for connection to supply/exhaust duct. In other applications, the filter retention system of the present disclosure can be mounted in a grid system with a single plenum supplying or exhausting air from the space.
[0032] The filter retention system can be fastened or otherwise secured to a mounting frame and can mechanically retain a filter cartridge while meeting the leakage requirements for the specific filter type, as noted in IEST recommended practice CC034: HEPA and ULPA Filter Leak Tests, under typical operating conditions. Typical filter cartridges can be operated with face velocities of up to 150 feet per minute and to a final resistance of 2.0 inches water gauge, or to other suitable design criteria.
[0033] In one exemplary embodiment, the filter retention system can include a plurality of filter alignment brackets that can be permanently attached to the filter retention system, to ensure proper alignment of the filter cartridges during installation and operation. The filter retention system can include a sealing knife edge that is integral to the mounting frame to ensure that air leakage does not occur. The filter cartridge can include sealant, such as a bed of material that does not harden and dry, and which can permanently stick to the hollow inner surface of the filter cartridge frame. Examples of suitable sealant materials include silicon gel, polyurethane gel, polymeric gel, or other suitable materials.
[0034] Proper alignment of the filter cartridge is achieved when the sealing knife edge extends into the hollow of the filter cartridge containing the filter cartridge sealant and subsequently into the filter cartridge sealant, with the peripheral edge of the sealing knife edge of the filter retention system being inserted into the filter cartridge sealant, and contacting only the filter cartridge sealant and not the filter housing, which can cause the seal to fail.
[0035] The present disclosure provides a simple, secure, and effective system to retain high efficiency filter cartridges, and which also allows for installation and removal of a filter cartridge without the use of tools. The present disclosure expedites removal, replacement and installation of high efficiency filter cartridges, substantially reducing the period of time of non-operation of the filter system in spaces where the filter system is installed. For ceiling mounted diffuser sizes up to 2 feet by 4 feet, this process can be accomplished by a single person.
[0036] Another feature of the present disclosure is that it facilitates proper alignment of the filter cartridge during installation, which helps to eliminate leakage at the interface of the filter cartridge sealant and the sealing knife edge. These and other features are attained by the filter retention system therefor, as described below in various exemplary embodiments and as shown in the drawings.
[0037] FIG. 1 is a diagram of filter retention system 25 in accordance with an exemplary embodiment of the present disclosure. Filter cartridge 4 is secured to filter retention system 25 by four filter retainer clips 1 and is aligned by the retainer clips 1 and two filter alignment brackets 2 . System mounting frame 3 incorporates the sealing knife edge 14 (not explicitly shown), which creates a seal with the filter cartridge sealant 12 (not explicitly shown). Rivets 24 are used to secure filter retainer clips 1 and filter alignment brackets 2 to system mounting frame 3 .
[0038] FIG. 2 is a perspective view of filter retainer clip in accordance with an exemplary embodiment of the present disclosure. Surface 6 of filter retainer clip 1 and surface 15 of filter alignment bracket 2 (not explicitly shown) facilitate proper alignment of filter cartridge 4 during installation, by guiding filter cartridge 4 into a proper position as it is inserted into filter retention system 25 . In particular, filter retainer clip 1 deforms in the direction towards system mounting frame 3 until filter cartridge 4 passes surface 6 , at which point filter retainer clip 1 springs back into position to lock against filter cartridge 4 . Surface 8 of filter retainer clip 1 and surface 16 of filter alignment bracket 2 restrict movement of filter cartridge frame 13 , which helps to ensure that filter cartridge 4 is properly aligned when it is installed. Likewise, during removal, filter retainer clip 1 is moved by asserting a force on surface 6 , such as by manual application of force, until filter cartridge 4 can be moved past filter retainer clip 1 .
[0039] FIG. 3 is a side view of filter retainer clip 1 in accordance with an exemplary embodiment of the present disclosure. Filter retainer clip 1 is formed in a particular shape to facilitate tool-less installation and removal, and to ensure proper alignment of filter cartridge 4 . Filter retainer clip 1 can be formed from a single piece of material, preferably of sheet steel (such as #302 stainless steel or spring steel, 0.03″ to 0.01″ thick or other suitable materials) formed by punching a blank from sheet stock and then by bending the blank along four bend lines to form five segments (base segment 10 , second segment 5 , third segment 6 , fourth segment 7 and fifth segment 8 ) in series at specific angles to one another.
[0040] As shown in FIG. 3 , second segment 5 subtends an angle A in the range of 88° to 95°, and preferably about 90°, with base segment 10 . Third segment 6 subtends an obtuse angle B in the range of 125° to 135°, and preferably about 130°, with second segment 5 . Fourth segment 7 subtends an acute angle C in the range of 48° to 52°, and preferably about 50°, with third segment 6 . Fifth segment 8 subtends an angle D in the range of 88° to 95°, and preferably about 90°, with fourth segment 7 .
[0041] Base segment 10 has protruding tabs with hole 9 in each to fasten filter retainer clip 1 to system mounting frame 3 with rivets 24 or in other suitable manners. Third segment 6 is gauged and angled to flex when a force is applied, allowing for installation and removal of filter cartridge 4 .
[0042] FIG. 4 is a plan view of filter cartridge 4 installed in system mounting frame 3 , in accordance with an exemplary embodiment of the present disclosure. As can be seen in FIG. 4 , four filter retainer clips 1 and two filter alignment brackets 2 hold filter cartridge 4 in position within system mounting frame 3 , and the four filter retainer clips 1 further secure filter cartridge 4 against system mounting frame 4 .
[0043] FIG. 5 is a sectional view taken on the plane 5 - 5 in FIG. 4 , in accordance with an exemplary embodiment of the present disclosure. As shown in FIG. 5 , sealing knife edge 14 penetrates filter cartridge sealant 12 in the center of the sealant as a function of angle B and third segment 6 of filter retainer clip 1 . Filter cartridge frame 13 as shown contains filter material 11 . Filter retainer clips 1 are held in position by rivets 24 or in other suitable manners, and hold filter cartridge 4 in position within system mounting frame 3 .
[0044] FIG. 6 is a sectional view taken on the plane 6 - 6 in FIG. 4 , in accordance with an exemplary embodiment of the present disclosure. FIG. 6 shows filter cartridge 4 in its installed position with sealing knife edge 14 penetrating filter cartridge sealant 12 as a function of angle E and third segment 16 of filter alignment bracket 2 , which controls the location of filter cartridge 4 within system mounting frame 3 . In this manner, sealing knife edge 14 extends into the hollow of the frame of filter cartridge 4 that contains filter cartridge sealant 12 . Rivet 12 holds filter alignment bracket 2 in position.
[0045] FIG. 7 is a perspective view of filter alignment bracket 2 , in accordance with an exemplary embodiment of the present disclosure. Filter alignment bracket 2 can be formed from a single piece of austenitic stainless steel, cold rolled steel or aluminum, 0.03″ to 0.01″ thick, or other suitable materials. Filter alignment bracket 2 can be formed by punching a blank from sheet stock and then by bending the blank along two bend lines to form three segments (base segment 17 , second segment 15 and third segment 16 ) in series at specific angles to one another. Base segment 17 has protruding tabs with a hole 18 in each to allow filter alignment bracket 2 to be secured to system mounting frame 3 by rivets 24 , or in other suitable manners. Second segment 15 and third segment 16 are gauged and angled to restrict the movement of filter cartridge 4 during installation, to ensure that sealing knife edge 14 extends into the hollow of filter cartridge frame 13 that contains filter cartridge sealant 12 and into filter cartridge sealant 12 , with the peripheral edge of sealing knife edge 14 within filter cartridge sealant 12 , and contacting only filter cartridge sealant 12 . In this manner, an air-tight seal is formed.
[0046] FIG. 8 is a side view of filter alignment bracket 2 , in accordance with an exemplary embodiment of the present disclosure. As shown in FIG. 8 , second segment 15 subtends an acute angle E in the range of 45° to 80°, and preferably about 60°, relative to base segment 17 . Third segment 16 subtends an obtuse angle B in the range of 100° to 135°, and preferably about 120°, relative to second segment 15 .
[0047] FIG. 9 is a detail view of an installed filter cartridge 4 in accordance with an exemplary embodiment of the present disclosure. Fourth segment 7 of filter retainer clip 1 makes contact with horizontal portion 19 of filter cartridge frame 13 in order to retain filter cartridge 4 when it is used in a supply configuration. Fifth segment 8 restricts the location of filter cartridge 4 , ensuring that sealing knife edge extends into the hollow of filter cartridge frame 13 that contains filter cartridge sealant 12 , and into filter cartridge sealant 12 with the peripheral edge of sealing knife edge 14 within filter cartridge sealant 12 contacting only filter cartridge sealant 12 . In this manner, an air tight seal is formed.
[0048] After filter retainer clip 1 deflects sufficiently, fifth segment 8 contacts system mounting frame 3 and prevents further deflection. This configuration protects filter retainer clip 1 from damage caused by plastic deformation. Filter retainer clip 1 can be formed of a suitable material, segment angles, width and thickness that are selected so as to securely retain filter cartridge 4 when filter face velocities are equal to or less than 150 feet per minute and the pressure drop across filter cartridge 4 is equal to or less than 2.0 inches water gauge, and allows for installation and deliberate removal of filter cartridge 4 without the use of tools.
[0049] FIG. 10 is a perspective view of air distribution device 28 incorporating filter retention system 25 in accordance with an exemplary embodiment of the present disclosure. In this exemplary embodiment, filter retention system 25 can be implemented as a part of air distribution device 28 for supply or exhaust air operation. Sealed plenum 21 of air distribution device 28 includes duct connection 20 , which is used to connect air distribution device 28 to a heating, ventilating and air conditioning (HVAC) system.
[0050] FIG. 11 is an exploded view of air distribution device 28 in accordance with an exemplary embodiment of the present disclosure. Device face 23 of air distribution device 28 determines the air flow pattern that will be delivered when supplying filtered air to a space. Filter retention system 25 holds filter cartridge 4 in position within air distribution device 28 .
[0051] FIG. 12 is a section view of air distribution device 28 , in accordance with an exemplary embodiment of the present disclosure. In this exemplary embodiment, air distribution device 28 receives contaminated air through duct connection 20 and provides filtered air to a ventilated space. Filter cartridge 4 is contained within sealed plenum 21 and filter retention system 25 , and delivers the filtered air to the ventilated space through device face 23 , which can be covered with a suitable material, such as a stainless steel grill.
[0052] FIG. 13 is a section view of air distribution device in exhaust operation, in accordance with an exemplary embodiment of the present disclosure. In this exemplary embodiment, air distribution device 28 receives contaminated air through device face 23 and provides filtered air to duct connection 20 . Filter cartridge 4 is contained within sealed plenum 21 and filter retention system 25 , and delivers the filtered air to the duct through duct connection 20 .
[0053] FIG. 14 is a perspective view of filter retainer clip 2 installed in filter retention system 25 , in accordance with an exemplary embodiment of the present disclosure. Filter retainer clip 2 is secured to system mounting frame 3 by rivets 24 , which are installed through holes in base segment 10 . Second segment 5 , third segment 6 and fourth segment 7 form a spring that allows a filter cartridge 4 to be installed and locked into position by filter retainer clip 2 .
[0054] FIG. 15 is a perspective view of multiple filter retention systems 25 installed within a single sealed plenum 26 , in accordance with an exemplary embodiment of the present disclosure. Sealed plenum 26 is attached to a grid system for mounting the filter retention systems 25 and has a duct connection 27 . This application can be used to either supply or exhaust air from the space.
[0055] It may be appreciated that the components of the system as described above are the exemplary embodiments of the present disclosure, and that many design changes may be made without affecting the utility of these components. For example the choice of material for the filter alignment brackets and the mounting frame is a matter for the designer, who will take into account to the application of the air flow device the filter retention system is installed in. Also, while the segments of the filter retainer clip and filter alignment brackets are straight, some of the segments might be curved.
[0056] Since the present disclosure is subject to modifications and variations, it is intended that the forgoing description and the accompanying drawings shall be interpreted as only illustrative of the present disclosure defined by the following claims.
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A filter retention system for releasably retaining a filter cartridge in an operable position within air supply and air exhaust systems is comprised of a filter cartridge, filter retainers, mounting frame with integral sealing knife edge and filter alignment brackets. The filter retainers allow for installation and removal of the filter cartridge without the use of tools. The retention system automatically aligns filter cartridges such that an airtight seal is created between the sealant containing groove in the filter cartridge and the sealing knife edge of the retention system.
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FIELD OF THE INVENTION
[0001] This invention is directed to a method and apparatus for securing a connection in a mechanical structure, fluid line, or electrical line, and particularly to a method and apparatus for securing connections that cannot readily be secured by traditional lock-wiring techniques.
BACKGROUND OF THE INVENTION
[0002] It has long been the practice to provide a secondary means for securing connections in mechanical structures, fluid lines, or electrical lines, to preclude undesired or inadvertent separation of the connection during operation. Often this involves a process known as lock-wiring.
[0003] For typical connections made with a connecting device having a rotating part, a length of lock-wire, passed through holes in a rotating part and secured to a non-rotating portion of the connecting device or a nearby stationary structure, is used to prevent the rotating part from loosening during operation in a way that would allow the connection to separate.
[0004] In connections that have no rotating parts, connections are similarly lock-wired by feeding a length of lock-wire through holes in mating halves of the connecting device, and securing the mating halves to one another by twisting the free ends of the lock-wire together in a manner that prevents the mating parts from separating from one another.
[0005] To ensure that the lock-wire is properly installed, and to allow a particular routing of lock-wire for a given connection to be standardized and inspected, the routing is generally recorded on process drawings, and lock-wire pliers are typically utilized for tightly twisting and positioning the lock-wire between the holes in the connecting device and any point of attachment to supporting structure. Some connections are so small, or inaccessible, however, that it is not possible to use traditional lock-wiring techniques as described above. For these connections, other securing methods and apparatus are required.
[0006] It is an object of my invention to provide an improved apparatus and method for securing connections. It is also an object of my invention to provide a securing method and apparatus that does not require passing lock-wire through holes in connecting devices. It is a further object of my invention that the improved securing method and apparatus be applicable to a wide variety of connections, including those that do not have rotating parts. Another object of my invention is to provide a method and apparatus for securing a connection without using tools. It is also an object of my invention to provide an improved securing method and apparatus that can be readily duplicated and inspected on multiple connections to optimize manufacturing and quality control operations.
SUMMARY OF THE INVENTION
[0007] My method and apparatus for securing a connection achieve the above objects through the use of a commonly available commercial lanyard, and a lanyard retainer. The lanyard retainer has an elongated center section adapted for positioning the retainer adjacent the connection, and means at both ends of the retainer for engaging and retaining the lanyard.
[0008] In one form of my invention, a connection, formed by a first and a second connector half mating with one another along an axis of connection to join a first and a second line extending respectively from the first and second connector halves, is secured by positioning the lanyard retainer generally along the axis of connection with the first end of the retainer adjacent the first connector half and a second end of the retainer adjacent the second connector half. A first end of a lanyard is then passed about the first connector half, and/or the first line extending from the first connector half, to form a first loop in the lanyard which is secured to the first end of the retainer. The free end of the lanyard extending from the first loop is then routed at least partially along the axis of connection, and passed about the second connector half, and/or the second line extending from the second connector half, to form a second loop in the lanyard which is secured to the second end of the retainer. With the retainer securing the lanyard about the connection in this manner, the first and second connector halves are precluded from moving with respect to one another along the axis of connection, thereby securing the connection against separation.
[0009] In a preferred form of my invention, the lanyard is a commercially available wire cable of small diameter having a metal block larger than the cable diameter welded, swaged, cast or otherwise permanently affixed to a first end of the lanyard. The retainer is formed from a length of wire having an elongated central section adapted for positioning the retainer adjacent a connection formed by a first and a second connector half mating with one another along an axis of connection, with a first end of the retainer adjacent the first coupling half and a second end of the retainer adjacent the second connector half.
[0010] The first end of the retainer is formed into a helical spring with a central opening defining a first eye of the retainer. The first eye is sized to allow a free end of the lanyard extending from the metal block to pass through the first eye twice, to form a first loop in the lanyard. The first eye is too small to allow the metal block of the lanyard to pass through, however, so that the first loop in the lanyard can be tightened like a noose, around the first connector half, by pulling on the free end of the lanyard. The second end of the retainer is formed into a helical spring having closely spaced or abutting coils, adapted for gripping the lanyard between the coils. The closely spaced coils also form a central opening, defining a second eye of the retainer, for passage of the lanyard.
[0011] To secure a connection, the retainer is positioned adjacent the connection. The lanyard is looped and tightened around the first end of the connector. The free end of the lanyard is then routed along the axis of connection, looped around the second end of the connection one or more times, and the free end is secured by passing it though the second eye and pulling it between the coils of the helical spring at the second end of the retainer to secure the lanyard and the connection.
[0012] The specific routing of the lanyard for each type of connection can be varied for optimal installation and security. Once a preferred routing is established, it can be recorded in a series of photographs or process drawings, so that the routing can be duplicated and readily inspected for quality control when securing similar connections.
[0013] Other forms, aspects and advantages of my invention will be apparent upon review of the following detailed description and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 depicts a fluid connector secured with a securing device according to my invention;
[0015] [0015]FIG. 2 depicts an electrical connector secured with a securing device according to my invention;
[0016] [0016]FIG. 3 depicts a lanyard retainer of a securing device according to my invention;
[0017] [0017]FIGS. 4 and 5 are partial views of the lanyard retainer of FIG. 3, viewed as indicated by arrows 4 and 5 respectively in FIG. 3; and
[0018] [0018]FIGS. 6 a - n depict a series of steps in a method of securing a connection using a securing device according to my invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] [0019]FIG. 1 depicts a connection formed by a first and second connector half 12 , 14 mating with one another along an axis of connection 16 to join a first and second fluid line 18 , 20 extending respectively from the first and second connector halves 12 , 14 . The connection 10 is secured with a securing device, generally designated 22 , comprising a lanyard 24 , and a lanyard retainer, generally designated 26 . The lanyard retainer 26 has an elongated central “leg” section 28 adapted to position the retainer 26 generally along the axis of connection 16 , with a first end 30 of the retainer 26 adjacent the first connector half 12 , and a second end 32 of the retainer 26 adjacent the second connector half 14 .
[0020] As shown in FIGS. 3 - 5 , the lanyard retainer 26 , in the embodiment of my invention depicted in FIG. 1, is formed from a continuous length of resilient wire having a central linear section forming the elongated central body, or leg 28 of the retainer 26 , and defining a longitudinal axis 34 of the retainer 26 . The first and second ends 30 , 32 of the retainer 26 are terminated in first and second helical springs 36 , 38 .
[0021] As shown in FIG. 4, the first helical spring 36 at the first end 30 of the retainer 28 provides a means for retaining one end of the lanyard 24 by having the coils 44 configured to define a first eye 40 adapted for receiving and retaining the first end of the lanyard 24 . The second helical spring 38 at the second end 32 of the retainer 26 has closely spaced coils 42 a - g for gripping the lanyard 24 between adjacent coils.
[0022] The first helical spring 36 , at the first end 30 of the retainer 26 , has a series of coils 44 wound at a first radius R 1 about a first winding axis 46 which is oriented substantially perpendicular to the longitudinal axis 34 of the retainer 26 . The first winding axis 46 is spaced a distance of R 1 from the leg 28 such that the linear section 28 joins smoothly with a first one of the coils 44 at the first end 30 of the linear section 28 , and such that the linear section 28 does not pass through the eye 40 of the coils 44 of the first helical spring 36 of the retainer 26 .
[0023] As shown in FIGS. 3 and 5, the closely spaced coils 42 a - g of the second helical spring 38 are wound at a second radius R 2 about a second winding axis 48 oriented substantially perpendicular to the longitudinal axis 34 of the retainer 26 and passing through the longitudinal axis 34 . In contrast to the first helical spring 36 as described above, the leg 28 of the retainer passes beneath the coils 42 a - g at the second end 32 of the retainer to substantially bisect a second eye 50 formed by the coils 42 a - g of the second helical spring 38 , and joins smoothly with the first coil 42 a in a third radius R 3 which is smaller than the second radius R 2 .
[0024] By virtue of this winding arrangement, the first coil 42 a of the second spring 38 is really only a “half-coil.” When viewed from the bottom as shown in FIG. 5, therefore, both the first half coil 42 a , and a portion of the second coil 42 b are visible on alternate sides of the leg 28 . With this arrangement, the free end of a lanyard 24 extending along and below the leg 28 as depicted in FIG. 5 can be easily pulled between the first coil 42 a and the second coil 42 b , to secure the free end of the lanyard. The configuration of the first coil 42 a and leg 28 of the retainer 26 thus act as a guide to facilitate pulling the lanyard 24 between the first and second coils 42 a , 42 b.
[0025] For reasons that will be evident from the discussion below, the radius R 1 of the coils 44 of the first helical spring 36 is smaller than the radius R 2 of the coils 42 a - g of the second helical spring 38 .
[0026] In the retainer 26 depicted in FIGS. 1 - 5 , the coils 44 , and 42 are wound in opposite directions about their respective winding axes 46 , 48 , and the first and second winding axes 46 , 48 are oriented substantially parallel to one another to facilitate winding of the helical springs 36 , 38 . Other winding arrangements and orientations of the helical springs may be more or less advantageous in other forms of a lanyard retainer in accordance with my invention, and are contemplated within the scope of the appended claims. I also contemplate lanyard retainers in accordance with my invention in which the elongated central body may be neither linear nor substantially straight, and wherein the first end 30 of the retainer may be configured in some manner other than a helical spring 36 .
[0027] As shown in FIG. 1, the lanyard 24 is a commercially available wired cable 52 of small diameter, having a metal block 54 larger than the diameter of the cable 52 welded, swaged, cast, or otherwise permanently affixed to a first end of the lanyard 24 . The Radius R 1 of the first helical spring 36 is sized to form an eye 40 which will allow the free end of the lanyard 24 extending from the metal block 54 to pass through the first eye 40 twice to form a first loop 56 in the lanyard 24 . The first winding radius R 1 is selected to form a first eye 40 which is too small, however, to allow the metal block 54 of the lanyard 24 to pass through the first eye 40 , so that the first loop 56 of the lanyard 24 can be tightened like a noose around the first connector half 12 , or around the first line 18 , by pulling on the free end of the lanyard 24 . After tightening the first loop 56 , the free end of the lanyard 24 is routed along the leg 28 of the lanyard retainer 26 passed and beneath the first coil 42 a of the second helical spring 38 and secured between the first and second coils 42 a , 42 b of the spring 38 . The free end of the lanyard 24 is then passed one or more times above the second connector half 14 , and/or the second line 20 extending from the second connector half, to form a second loop 58 , and possibly a third loop 60 , in the lanyard, and the free end is secured by pulling it between and wrapping it around and between the coils 42 a - g of the second end of the retainer 26 .
[0028] The exact routing of the lanyard 24 , the number of times the lanyard 24 is wrapped about the second connector half 14 , and/or any intermediate connector parts, will vary depending upon the type of connection being secured. FIG. 2 for instance, illustrates an application of a retaining device 22 , as described above with relation to FIGS. 1 and 3- 5 , applied to an electrical connector 62 . As will be understood by comparing FIGS. 1 and 2, the particular manner in which a securing device 22 according to my invention is configured and applied to secure a given connection, will vary depending upon the configuration of the connection and its component parts. Those skilled in the art will readily recognize, however, that a securing device according to my invention provides a convenient means and method for securing a connection without the use of tools, and provides a means and method of securing connection which may not be amenable to traditional lock-wiring techniques FIGS. 6 a - n depict a series of steps which may be utilized for securing a connection of the type shown in FIGS. 1 and 2. To facilitate clarity in the illustrations, the “connection” in FIGS. 6 a - n , is simulated by a cylinder 64 having a central section 66 depicting a connection extending between a first and a second annular groove 68 , 70 respectively depicting a first and second line to be joined by the simulated connector 66 . This clarifies the illustrations by omitting non essential detail of the connecting elements.
[0029] As shown in FIG. 1, the retainer 26 is positioned with the leg 28 extending along the central section 66 . The free end of the lanyard 24 is inserted downward through the first eye 40 of the retainer 26 , and then wrapped around the groove 68 and passed back up through the first eye 40 to form a first loop 56 of the securing device 22 . As shown in FIG. 6 b , the free end of the lanyard 24 is then pulled to seat the first loop 56 tightly in the annular groove 68 , removing all excess slack from the lanyard 24 . As shown in FIG. 6 c , the free end of the lanyard 24 is then extended along the leg 28 of the retainer 26 and under the first coil 42 a of the second helical spring 38 of the retainer 26 . With a firm pull, the free end of the lanyard 24 will “snap-in” between the first and second coils 42 a , 42 b of the second helical spring 38 .
[0030] Optionally, as shown in FIG. 6 d , an extra half-hitch 76 can be made around the connection (central section 66 ) to grip the central section and hold it against rotation. If this extra half-hitch 76 is used, it is made before extending and securing the free end of the lanyard 24 to the second helical spring 38 , as shown in FIG. 6 c . For clarity of illustration, this optional half-hitch 76 is not illustrated in FIGS. 1 and 2, or in FIGS. 6 a - c and FIGS. 6 e - n.
[0031] As illustrated in FIG. 6 e the free end of the of the lanyard 24 is then wrapped twice in a clockwise direction around the connection within the second annular groove 70 to form a second loop 58 and a third loop 60 . At the completion of the second wrap of the free end of the lanyard 24 , the free end is positioned along the leg 28 at a point between the first and second helical springs 36 , 38 , and just to the left of the second helical spring 38 as depicted in FIG. 6 e . As shown in FIG. 6 f , the free end of the cable is then continued across the leg 28 and fed under the second or third loop 58 , 60 , on the backside of the cylinder 64 , and pulled firmly to remove all slack. By virtue of the construction of the retainer 26 , the free end of the lanyard 24 will engage both loops 56 and 60 and be pulled between the first and second coils 42 a , 42 b of the spring 38 to form a locking point.
[0032] As shown in FIG. 6 g , the free end of the lanyard 24 is then looped in a clockwise direction around the outside of the second helical spring 38 and passed under the leg 28 between the leg 28 and the central section 66 of the cylinder 64 , and the free end is pulled to remove all slack from the lanyard 24 . The free end of the lanyard is then fed upward from the bottom of the second helical spring 38 through the second eye 50 as shown in FIG. 6 h . The free end of the lanyard 24 is pulled completely through the second eye 50 , as shown in FIG. 6 i and inserted under the leg 28 from the far side of the cylinder 64 to form a loop 78 extending out 20 from the top of the second helical spring to the underside of the leg 28 . The free end of the lanyard 24 is then inserted between the second and third coils 42 b - c of the second helical spring 38 as shown in FIG. 6 j , but the loop 78 thus formed is not pulled tight.
[0033] As shown in FIG. 6 k , the free end of the lanyard 24 is then inserted through the loop 78 formed as shown in FIGS. 6 i and 6 j and above the leg 28 , and the free end of the lanyard 24 is pulled firmly to tighten the loops and remove all slack from the cable as shown in FIG. 6 l.
[0034] At this point, the connection is fully secured, and any excess length of the lanyard 24 can be trimmed off. Alternatively, any excess length of the lanyard 24 may be woven around the retainer 26 and through the loops 56 , 58 , 60 , as shown in FIG. 6 m.
[0035] In some applications, it may also be desirable to install an identification tag 72 , which can also be used to secure the free end of the lanyard 24 , as shown in FIG. 6 n . In such applications, it is not intended that the identification tag 72 function as a locking device.
[0036] Although I have provided a number of exemplary embodiments in the preceding discussion, and accompanying drawings those having skill in the art will recognize that my invention may be practiced in many alternate forms within the scope of the appended claims. It is understood, therefore, that the spirit and scope of the appended claims should not be limited to the specific embodiments described and depicted herein.
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The problem of securing a connection in a mechanical structure. fluid line, or electrical line, that can not readily be secured by traditional lock-wiring techniques, is solved through a method and apparatus for securing a connection with a commonly available commercial lanyard and a lanyard retainer. The lanyard retainer has an elongated center section adapted for positioning the retainer adjacent the connection, and means at both ends of the retainer for engaging and retaining the lanyard.
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This application is a Continuation of Internation Application No. PCT/HU2005/000120, filed Nov. 9, 2005.
FIELD OF THE INVENTION
The present invention relates to adenozin A 3 receptor ligands labeled with iodine isotops of mass number 125, within those favourably to antagonists and their isomers, to the experimental materials containing them, to a process for the preparation of the compounds of the general formula (I)
and their isomers, to the new intermediates of the general formula (II)
and to the preparation thereof.
BACKGROUND OF THE INVENTION
Adenosine is a well-known component of several endogenous molecules (ATP, NAD + , nucleic acids). Besides, it plays an important regulatory role in many physiological processes. The effect of adenosine on heart function was discovered already in 1929. (Drury and Szentgyörgyi, J Physiol 68:213, 1929). The identification of an increasing number of physiological functions mediated by adenosine and the discovery of new adenosine receptor subtypes give possibilities for therapeutic application of specific ligands (Poulse, S. A. and Quinn, R. J. Bioorganic and Medicinal Chemistry 6:619, 1998).
To date, the receptors for adenosine have been classified into three main classes: A 1 , A 2 and A 3 . The A 1 subtype is partly responsible for inhibiting the adenylate cyclase by coupling to G i membrane protein, partly influences other second messenger systems. The A 2 receptor subtype can be subdivided into two further subtypes—A 2a and A 2b —, which receptors stimulate the adenylate cyclase activity. The sequence of adenosine A 3 receptors have been recently identified from rat testis cDNA library. Later it was proved that it corresponds to a novel, functional adenosine receptor. The activation of the A 3 receptors is connected also with several second-messenger systems: inhibiting of adenylate cyclase, stimulating phospholipase C and D.
The adenosine receptors are found in several organs and regulate their functions. Both A 1 and A 2a receptors play important roles in the central nervous system and cardiovascular system. In the CNS, the adenosine inhibits the release of synaptic transmitters which effect is mediated by A 1 receptors. In the heart, also the A 1 receptors mediate the negative inotropic, chronotropic and dromotropic effects of adenosine. The adenosine A 2a receptors, which located relatively in a higher amount in the striatum, display a functional interaction with dopamine receptors in regulating the synaptic transmission. The A 2a adenosine receptors on endothelial and smooth muscle cells are responsible for adenosine-induced vasodilation.
On the basis of mRNA identification, the A 2b adenosine receptors are widely distributed in different tissues. They have been identified almost in every cell type, but its expression is the highest in the intestine and the bladder. This subtype probably also has important regulatory function in the regulation of the vascular tone and plays a role in the function of mast cells.
Contrary to A 1 and A 2a receptors, where the tissue distribution was detected on the protein level, the presence of A 2b and A 3 receptors was detected on the basis of their mRNA level. Expression levels for A 3 adenosine receptors are rather low comparing to other subtypes and highly species dependent. A 3 adenosine receptors are expressed primarily in the central nervous system, testis, immune system and appear to be involved in the modulation of mediator release from mast cells in immediate hypersensitivity reaction.
For therapeutic use it is essential to ensure that the molecule does not bind, or bind only in the case of very high concentration to the A 1 , A 2a , and A 2b sub-types of the adenosine receptor. Our present invention relates to the compounds of the general formula (I) labeled with iodo isotops of mass number 125, and to their salts, solvates and isomers, which have great selectivity for the A 3 sub-type of the adenosine receptor.
The [ 3 H]-MRE 3008-F20 adenosine A 3 receptor antagonist radioligand is known from the literature. (P. G. Baraldi, Bioorganic and Medicinal Chemistry Letters, 10, 209-211, 2000). Also known is the [ 3 H]PSB-11 A 3 receptor antagonist radioligand (C. H. Müller, Bioorganic and Medicinal Chemistry Letters, 12, 501-503, 2002).
Our aim was to prepare A 3 radioligands of antagonistic effect labelled with iodine isotop of mass number 125, since these have higher specific activity compared to those labelled with tritium. The goal was to prepare radioligands having strong affinity to the adenosin A 3 receptor, but at the same time showing high selectivity within the subtypes, i.e. binding in much higher concentration to the A 1 , A 2a and A 2b receptors. A further aim was to have radioligands suitable for the characterisation of the A 3 receptor in the different tissues and for the study of the mechanism of action of A 3 antagonists.
SUMMARY OF THE INVENTION
The subject of our invention is compounds of the general formula (I)
and their isomers—where in the formula
R 1 stands for hydrogen atom or a straight or branched C 1-4 alkyl group, or a C 3-6 cycloalkyl group, or a phenyl group, thienyl group, or furyl group, optionally substituted with one or more straight or branched C 1-4 alkyl group, straight or branched C 1-4 alkoxy group, or halogen atom, or for a 5- or 6-membered heteroaromatic ring-containing one, two or three nitrogen atoms-, or for a 5-membered heteroaromatic ring-containing one nitrogen atom and one oxygen atom or one nitrogen atom and one sulphur atom—optionally substituted with one or more straight or branched C 1-4 alkyl group, straight or branched C 1-4 alkoxy group, or halogen atom; R 2 stands for hydrogen atom or for a straight or branched C 1-4 alkyl group, or for a phenyl-, benzyl-, thienyl- or furyl-group-optionally substituted with a methylenedioxy group, or one or more straight or branched C 1-4 alkyl group, or straight or branched C 1-4 alkoxy-, hydroxyl-, trifluoromethyl- or cyano-group, or halogen atom-, or for a 5- or 6-membered heteroaromatic ring-containing one, two or three nitrogen atoms, or one nitrogen atom and one oxygen atom, or one nitrogen atom and one sulphur atom—optionally substituted with one or more straight or branched C 1-4 alkyl group, straight or branched C 1-4 alkoxy group, or halogen atom.
DETAILED DESCRIPTION OF THE INVENTION
Definition of the Terms
Detailed meanings of the above substituents are as follows:
By straight or branched C 1-4 alkyl group we mean methyl-, ethyl-, propyl-, isopropyl-, butyl-, isobutyl-, secondary-butyl-, tert.-butyl-, preferably ethyl- or methyl group.
By straight or branched C 1-4 alkoxy group we mean methoxy-, ethoxy-, propoxy-, isopropoxy-, butoxy-, isobutoxy-, sec.-butoxy-, tert.-butoxy-, preferably ethoxy- or methoxy group.
By C 3-6 cycloalkyl group we mean cyclopropyl-, cyclobutyl-, cyclopentyl- or cyclohexyl group.
The heteroaromatic ring containing one or two or three nitrogen atoms may mean pyrrole, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, pyridine, pyrimidine, pyridazine, pyrazine and 1,3,4-triazine ring. The ring is optionally substituted with a C 1-4 alkyl, or alkoxy group or by a halogen atom.
The heteroaromatic ring containing one nitrogen atom and one oxygen or one sulphur atom means oxazole, isoxazole, thiazole, isothiazole ring. The ring is optionally substituted with a C 1-4 alkyl, or alkoxy group or by a halogen atom.
Particular Embodiments of the Invention
A favourable group of compounds of the general formula (I) is formed by the compounds—wherein
R 1 stands for phenyl-, thienyl- or furyl group
R 2 stands for 4-methoxyphenyl-, 3-methylphenyl-, 3-methoxyphenyl-, 2-thienyl-, 3-thienyl-, 2-furyl- or 3-furyl group.
Especially favourable are the following compounds complying with the above criteria:
4-Methoxy-N-(6-[ 125 I]iodo-4-benzylamino-3-cyanoquinolin-2-yl)benzamide
4-Methoxy-N-(6-[ 125 I]iodo-4-[2-thienylmethylamino]-3-cyanoquinolin-2-yl)benzamide.
Further subject of the invention is the preparation of the compounds of the general formula (I)
and of the intermediates of the general formula (II).
The intermediates of general formula (II) which are used in the preparation process according to the invention, are novel. In the general formula (II) substituents R 1 and R 2 have the meanings as defined above, R 3 stands for straight or branched C 1-4 alkyl group, preferably methyl- or butyl group.
In the process according to our invention the compounds of the general formula (I) are prepared by reacting the appropriate compounds of the general formula (II) with unsupported [ 125 I]NaI, in the presence of an oxidant.
The reaction is carried out in aqueous methanolic medium (pH 3), at room temperature.
As oxidizing agents, peroxides for example hydrogen peroxide, N-halogeno-succinamides e.g. N-chloro-succinamide, or chlorosulphonamides, preferably chloramine-T can be used. The product is purified by reversed-phase high-performance liquid chromatographic (RP-HPLC) method using silica gel based C 18 modified packing as stationary phase and methanol-water binary mixture containing 0.1% (v/v) trifluoroacetic acid as eluent system, with flow rate of 0.9 ml/min. Detection is carried out by UV at 272 nm; detection of radioactivity is carried out by flow liquid scintillation method.
According to our invention the compound of general formula (II)
can be prepared from the appropriate quinoline of the general formula (III)
wherein R 1 and R 2 have the meanings as defined above and X stands for iodo- or bromo atom—by reacting it in the presence of palladium catalyst, organic or inorganic base and organic solvent, with a hexaalkyl-distannane compound. The product of general formula (II) is isolated. The exchange of the halogen atom for trialkyl-stannyl group is carried out in an organic solvent, for example in dioxane or dimethylformamide, or favourably in N-methyl-2-pyrrolidone. The reaction can be performed in a wide temperature range, preferably between 20° C.-100° C. As organic base trialkylamines, preferably triethylamine can be applied. For inorganic base alkali hydroxides, carbonates and acetates, preferably potassium acetate can be used. In the reaction palladium acetate, palladium chloride or tetrakis(triphenylphosphine)palladium(0) catalysts can be used (Z. P. Zhuang. M. P. Kung, C. Hou, D. M. Skovronsky, T. L. Gur, K. Plössl, J. Q. Trojanowski, V. M. Y. Lee, H. F. Kung, J. Med. Chem. 44, 1905, (2001)), but we have found that with tetrakis(tri(o-tolyl)phosphine)palladium(0) catalyst faster reaction and better yield is achieved.
The compounds of the general formula (III)
can be synthesized by the method described in patent application WO 02/096879.
The process according to our invention is shown in Reaction Scheme 1.
Further details of the invention are demonstrated in the Examples, without limiting the claims to the Examples.
EXAMPLES
Example 1
4-Methoxy-N-(6-[ 125 I]iodo4-benzylamino-3-cyanoquinolin-2-yl)benzamide
In the general formula (I) R 1 stands for phenyl group, R 2 stands for 4-methoxyphenyl group.
a.) To 8 μl of 0.1 mg/ml methanolic solution of 4-methoxy-N-(6-tributylstannyl-4-benzylamino-3-cyanoquinolin-2-yl)benzamide are added 25 μl (1.1 nmol) of 1% (v/v) methanolic solution of trifluoroacetic acid and 70 MBq [ 125 I]NaI solution (21 μl). To the reaction mixture 5 μl (2 nmol) of 0.1 mg/ml aqueous solution of chloramine-T is added and the mixture is stirred at room temperature for 15 minutes. After the incubation period the reaction is stopped by the addition of 7 μl (3.5 nmol) of 0.1 mg/ml sodium pyrosulfite solution and the product is immediately purified by using RP-HPLC method, applying UV and radioactivity detection. By this manner 31 MBq of the title compound is obtained (molar activity 81.4 GBq/mmol), radiochemical purity >95%. The purified product is stored in methanol-water (0.1% TFA) 3:1 mixture (activity concentration: 29 MBq/ml).
b.) 4-Methoxy-N-(6-tributylstannyl-4-benzylamino-3-cyanoquinolin-2-yl)benzamide.
0.33 g of 4-methoxy-N-(6-iodo-4-benzylamino-3-cyanoquinolin-2-yl)benzamide is dissolved in 5 ml of N-methyl-2-pyrrolidone and to the solution 240 mg of potassium acetate, 50 mg of tetrakis(tri(o-tolyl)phosphine)palladium(0) and 0.6 ml of hexabutyl distannane are added. The reaction mixture is stirred at room temperature under argon atmosphere for 16 hours, then it is poured onto 20 ml of water and extracted with 2×20 ml of toluene. The united toluene phase is dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue is chromatographed on a silicagel coloumn using chloroform-ethyl acetate (10:0.5) mixture as eluent. After evaporation of the pure fractions 250 mg of the title compound is obtained.
1 H-NMR (CDCl 3 ) δ 0.9 (m, 9H), 1.1 (M, 6H), 1.3 (m, 6H), 1.55 (m, 6H), 3.8 (s, 3H), 5.08 (d, 2H), 7.06 (d, 2H), 7.2-7.4 (m, 5H), 7.55 (d, 2H), 7.9-8.1 (m, 3H), 8.66 (m, 1H), 10.7 (s, 1H).
Example 2
4-Methoxy-N-(6-[ 125 I]iodo-4-[2-thienylmethylamino]-3-cyanoquinolin-2-yl)benzamide
In the general formula (I) R 1 stands for thienyl group, R 2 stands for 4-methoxyphenyl group.
a.) To 8 μl (1.1 nmol) of 0.1 mg/ml methanolic solution of 4-methoxy-N-(6-tributylstannyl-4-[2-thienylmethylamino]-3-cyanoquinolin-2-yl)benzamide are added 25 μl (1.1 nmol) of 1% (v/v) methanolic solution of trifluoroacetic acid and 70 MBq [ 125 I]NaI solution (21 μl). To the reaction mixture 5 μl (2 nmol) of 0.1 mg/ml aqueous solution of chloramine-T is added and the mixture is stirred at room temperature for 15 minutes. After the incubation period the reaction is stopped by the addition of 7 μl (3.5 nmol) of 0.1 mg/ml sodium pyrosulfite solution and the product is immediately purified by RP-HPLC method, while applying UV and radioactivity detection. By this manner 28 MBq of the title compound is obtained (molar activity 81.4 GBq/mmol), radiochemical purity >95%. The purified product is stored in methanol-water (0.1% TFA) 3:1 solvent mixture (activity concentration: 28 MBq/ml).
b.) 4-Methoxy-N-(6-tributylstannyl-4-[2-thienylmethylamino]-3-cyanoquinolin-2-yl)benzamide.
0.3 g 4-Methoxy-N-(6-iodo-4-[2-thienylmethylamino]-3-cyanoquinolin-2-yl)benzamide is dissolved in 5 ml of N-methyl-2-pyrrolidone and to the solution 240 mg of potassium acetate, 50 mg of tetrakis(tri(o-tolyl)phosphine)palladium(0) and 0.6 ml of hexabutyl distannane are added. The reaction mixture is stirred at room temperature under argon atmosphere for 16 hours, then it is poured onto 20 ml of water and extracted with 2×20 ml of toluene. The united toluene phase is dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue is chromatographed on a silicagel coloumn using chloroform-ethyl acetate (10:0.5) mixture as eluent. By evaporating the pure fractions 235 mg of the title compound is obtained.
1 H-NMR (CDCl 3 ) δ 0.9 (m, 9H), 1.1 (M, 6H), 1.3 (m, 6H), 1.55 (m, 6H), 3.85 (s, 3H), 5.1 (d, 2H), 6.9-7.17 (m, 4H), 7.43-7.54 (m, 2H), 8.03 (m, 3H), 8.72-8.82 (m, 2H), 10.86 (s, 1H).
Example 3
A./ Biological Methods
Human Adenozin A 1 Receptor Binding
Preparing membrane suspension: collect ovarium cells of cloned Chinese hamster expressing human A 1 receptors (further: CHO-hA 1 ), wash them three times with PBS, centrifuge (1000×g 10 min.) and homogenize (B.Braun Potter S) at 1500/min rotation speed. Buffer: 50 mM Tris HCl, pH 7,4. Centrifuge this homogenized mixture (43.000 g, 10 min), suspense the pellet in the above buffer with adjustment of the protein concentration to 5 mg/mL (Bradford method) and complete with 2 U/mL ADA.
Binding protocol: incubate CHO-hA 1 membrane preparation (50 μg protein content), in the presence of the test compound and 10 nM [ 3 H]CCPA (2-chloro-N 6 -cyclopenthyl-adenosine) (80.000 dpm) in incubation buffer (50 mM Tris HCl, pH 7.4, 2 U/mL adenosine deaminase). The non-specific binding is defined in the presence of 10 μM R-PIA (N 6 -[L-2-phenylisopropyl]adenosine) in a total volume of 100 μL for 3 hr at room temperature. Filter over Whatman GF/B glass fibre filters (presoaked in 0.5% polyethylimine for 3 hours), wash 4× with 1 mL ice-cold 50 mM Tris HCl (pH 7.4) on 96-well Brandel Cell Harvester. Detection of activity: in 96-well plate in the presence of HiSafe-3 cocktail in beta-counter (1450 Microbeta, Wallac). Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100
Human Adenosine A 2a Receptor Binding
Incubate 7 μg of membranes (human A 2 , adenosine receptors transfected into HEK-293 cells, source: Receptor Biology, Inc.), in the presence of the test compound and 20 nM [ 3 H]CGS-21680 (2-[p-(2-carbonylethyl)phenylethylamino]-5′-N-ethylcarboxamido-adenosine) (200.000 dpm) in incubation buffer (50 mM Tris HCl, 10 mM MgCl 2 , 1 mM EDTA, 2 U/mL adenosine deaminase, pH 7.4). The non-specific binding is defined in the presence of 100 μg NECA (5′-N-ethylcarboxamido-adenosine) in a total volume of 100 μl for 90 min at room temperature. Filter in vacuum over Whatman GF/B glass fibre filters (presoaked for 3 hours in 0.5% polyethylimine), wash 4× with 1 mL ice-cold buffer (50 mM Tris HCl, 10 mM MgCl 2 , 1 mM EDTA, 0.9% NaCl, pH 7.4) on 96-well Brandel Cell Harvester. Detection of activity: in beta-counter (1450 Microbeta, Wallac) in the presence of 200 μL HiSafe-3 cocktail. Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100.
Human Adenosine A 2b Receptor Binding
Binding protocol: incubate 20.8 μg of membranes (human A 2b adenosine receptors transfected into HEK-293 cells, source: Receptor Biology, Inc.), in the presence of the test compound and 32.4 nM [ 3 H]DPCPX (8-cyclopenthyl-1,3-dipropylxanthine) (800.000 dpm) in incubation buffer (50 mM Tris-HCl, 10 mM MgCl 2 , 1 mM EDTA, 0.1 mM benzamidine, 2 U/mL adenosine deaminase, pH 6.5). The non-specific binding is defined in the presence of 100 μM NECA (5′-N-ethylcarboxamido-adenosine) in a total volume of 100 μL for 30 min at room temperature. Filter under 25 Hgmm vacuum over Whatman GF/C glass fibre filters (presoaked in 0.5% polyethylimine for 3 hours), wash 4× with 1 mL ice-cold 50 mM Tris HCl (pH 6.5) on 96-well Brandel Cell Harvester. Detection of activity: in beta-counter (1450 Microbeta, Wallac) in the presence of 200 μL of HiSafe-3 cocktail. Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100
Human Adenosine A 3 Receptor Binding
Preparing membrane suspension: collect ovarium cells of cloned Chinese hamster expressing human A 3 receptors (further: CHO-hA 3 ), wash them three times with PBS, centrifuge (1000×g 10 min.) and homogenize (B.Braun Potter S) at 1500/min rotation speed. Buffer: 50 mM Tris, 10 mM MgCl 2 , 1 mM EDTA, pH 8.0. Centrifuge this homogenized mixture (43.000 g, 10 min), suspense the pellet in the above buffer with adjustment of the protein concentration to 0.1 mg/mL (Bradford method) and complete with 2 U/mL ADA.
Receptor Binding in the Presence of [ 125 I]AB-MECA:
Incubate the CHO-hA 3 membrane preparation (protein content 2 μg) in the presence of the test compound and 0.5 nM [ 125 I]AB-MECA (4-amino-3-iodo-benzyl-5′-N-methylcarboxamide-adenosine) (100.000 cpm) in incubation buffer (50 mM Tris, 10 mM MgCl 2 , 1 mM EDTA, 2 U/mL adenosine deaminase, pH 8.0). The non-specific radioligand binding is defined in the presence of 100 μM R-PIA (N 6 -[L-2-phenylisopropyl]adenosine) in a total volume of 50 μL for 60 min at room temperature. Filter under 25 Hgmm vacuum over Whatman GF/C glass fibre filters (presoaked in 0.5% polyethylimine for 3 hours), wash 4× with 1 mL ice-cold buffer (50 mM Tris, 10 mM MgCl 2 , 1 mM EDTA, pH 8) on 96-well Brandel Cell Harvester. Detection of radioactivity: in gamma-counter (1470 Wizard, Wallac). Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100.
Receptor Binding in the Presence of the Radioactive Iodine-Containing Compound of Example 2/a:
Incubate the CHO-hA 3 membrane preparation (protein content 4 μg) in the presence of the test compound and 0.5 nM of the compound containing radioactive iodine (100.000 cpm), described in Example 2/a, in incubation buffer (50 mM Tris, pH 8.0, 10 mM MgCl 2 , 1 mM EDTA, 0.08% CHAPS, 0.5% BSA, 2 U/mL adenosine deaminase). The non-specific radioligand binding is defined in the presence of 100 μM R-PIA (N 6 -[L-2-phenylisopropyl]adenosine) in a total volume of 50 μL for 60 min at room temperature. Keep the isotop preparation and the reaction mixture in polyethylene tube to decrease adsorption. Filter under 25 Hgmm vacuum over Whatman GF/C glass fibre filters (presoaked in 0.5% polyethylimine for 3 hours), wash 4× with 1 mL ice-cold buffer (50 mM Tris (pH 8), 10 mM MgCl 2 , 1 mM EDTA, 0.08% CHAPS, 0.25% BSA) on 96-well Brandel Cell Harvester. Detection of radioactivity: in gamma-counter (1470 Wizard, Wallac). Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100.
B./ Biological Results
I Affinity of the Un-Labeled Iodine-Containing Compound Given in Example 2/b as Starting Material (i.e. the Un-Labeled Analogue of the New Radioligand Given in Example 2/a) to the Adenosine Receptor Sub-Types in the Presence of Known Radioligands
The affinity of the starting compound of Example 2/b to the adenosine A 3 receptor (K i =1.5 nM) exhibits at least thousand-fold selectivity compared to the other adenosine receptor sub-types (Table 1).
TABLE 1
Characterisation of the starting compound of Example 2/b
as regards its affinity to the adenosine receptors
hA 3
Inhibition in 1 μM
[ 125 I]AB-
hA 1
hA 2A
hA 2B
MECA
[ 3 H]CCPA
[ 3 H]CGS21680
[ 3 H]DPCPX
The starting
K i = 1.5 nM
4%
29%
−16%
compound of
Example 2/b
II/A Investigation of the New Radioactive Iodine-Containing Compound of Example 2/a on the Human Adenosine A 3 Receptor by Scatchard Analysis Used for the Characterisation of Radioligands
On the basis of radioisotop saturation curves, by Scatchard analysis (G. Scatchard, Ann. N. Y. Acad. Sci. 51:660, 1949) the dissociation constant (K D ) of the new radioligand of Example 2/a on CHO-hA 3 membrane preparation is determined. In the investigated concentration range (0.156 nM-10 nM) the radioligand binds to only one binding place in the presence of a membrane preparate containing 4 μg of protein. The value of K D was found to be 4 nM, the maximal binding capacity 985 femtomol/1 mg protein (see FIG. 1 ).
FIG. 1 : Scatchard saturation curve of the new radioligand of Example 2/a in the presence of CHO-hA 3 membrane preparation
II/B Comparison of a Known Adenosine A 3 Radioligand with the New Radioligand of Example 2/a on the Basis of the Affinity Values of Reference compounds, in the Presence of 4 μg CHO-hA 3 Preparate
Knowing the K D values, by the Cheng-Prusoff equation (Y. J. Cheng and W. H. Prusoff, Biochem. Pharmacol. 22:3099, 1973) the K i constants of the investigated reference compounds and that of the starting compound of Example 2/b (i.e. of the un-labeled analogue of the new radioligand of Example 2/a) were calculated on the basis of the IC 50 values. The reference compounds exhibited similar affinity values in the presence of the known and of the new radoligands, proving the suitability of the radioligand of Example 2/a. The un-labeled analogue of the new radioligand exhibited a K i value nearly equal to the K D value of the isotop-labeled form (4.0 nM and 1.3 nM), also proving the specific binding of the new radioligand (see Table 2).
TABLE 2
Comparison of a known adenosine A 3 radioligand and the new
radioligand of Example 2/a with the help of affinity values
of reference compounds, in the presence of 4 μg CHO-hA 3 preparation.
The radioligand given in
[ 125 I]AB-MECA
Example 2/a
K i
R-PIA
65 nM
150 nM
Cl-IB-MECA
3.3 nM
5.9 nM
The starting compound of
1.5 nM
1.3 nM
Example 2/b
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The invention relates to adenozin A 3 receptor ligands labeled with iodine isotops of mass number 125, within those favorably to antagonists and their isomers, to the experimental materials containing them, to a process for the preparation of the compounds of the general formula (I)
and their isomers, to the new intermediates of the general formula (II)
and to the preparation thereof.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an information device for judging traffic conditions and notifying information to a driver.
2. Description of Background Art
Methods have been proposed for determining traffic conditions by detecting another vehicle or a moving body that approaches the driver's vehicle while driving, and informing the driver of the traffic conditions.
For example, Japanese Patent Laid-open publication No. Hei. 2-216600 discloses a method where a receiver is provided in a vehicle for monitoring the traffic during travel, judging that another moving body is within a short distance by receiving a warning transmitted by a transmitter provided in that moving body, transmitting a warning and notifying the driver of the traffic conditions.
The driver hears and acknowledges this warning, judges the traffic conditions, and actuates operating means such as, for example, a throttle grip in the case of a motorcycle, to reduce the speed of the vehicle.
This warning is a not only an audible signal, but may also be a visible signal, such as the illumination of a display lamp.
In such prior art, since from the time a change occurs in traffic conditions until the driver causes an action in response to the change in conditions the driver follows a series of actions such as visibly or audibly perceiving the warning, recognizing it in his brain, judging conditions, sending operating instructions from his brain to his hands or feet, and then actually carrying out the operation. There is a limit to the extent by which a response time can be reduced from recognizing a warning to the actual human operation of the vehicle.
During an urgent situation, response time is preferably shortened, but there is the limitation described above, and it is possible to fail to recognize the warning due to overlooking, misreading, not hearing, or mishearing the warning if the driver becomes flustered when hurrying.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention has been conceived in view of the above points, and the object of the invention is to provide an information device that enables a substantial reduction in overall response time and makes it difficult to fail to recognize a warning.
In order to achieve the above described object, the present invention provides an information device including an external force generating means for supplying an external force to an operating means touched by the extremities, the hands or feet, of a driver at the time of the operation of a vehicle; judging means for receiving an external signal and judging traffic conditions; and control means for controlling the driving of the external force generating means based on the determined results of the judging means.
If an external signal is received and traffic conditions are judged, the external force generating means is driven based on the result of the judgement and the external force is supplied to operating means touched by the hands or feet of the driver for controlling driving devices of a vehicle while the vehicle is travelling. This means that information is conveyed to the hands or feet of the driver from the operating means to be operated not according to the hearing or seeing ability of the driver but according to the traffic conditions. Thus, there is no failure to recognize the warning and it is possible to significantly reduce the overall response time.
The present invention provides an information device wherein the external force generating means supplies external force to a throttle grip of a vehicle with handlebars.
If an external signal is received and an external force is supplied to the throttle grip to be actuated according to traffic conditions, information is conveyed directly to the hands of the driver from the throttle grip to be operated not according to the hearing or seeing ability of the driver but according to traffic conditions. Thus, there is no failure to recognize the warning and it is possible to significantly reduce the overall response time.
The present invention provides an information device wherein the external force generating means comprises at least one of an urging means for supplying an urging force to the throttle grip in a direction to reduce the number of engine revolutions, and excitation means for supplying vibration to the throttle grip.
If an external signal is received, vibration is applied to the throttle grip to be actuated according to traffic conditions, and an urging force is applied in a direction to reduce the number of engine revolutions. Thus, the driver recognizes the vibration or urging force directly acting on his hands, so there is no failure to recognize the warning and it is possible to significantly reduce the overall response time.
The present invention provides an information device wherein the external force generating means supplies external force to an accelerator pedal of a four wheeled vehicle.
If an external signal is received and external force is supplied to the accelerator pedal to be actuated according to traffic conditions, information is conveyed directly to the hands of the driver from the accelerator pedal to be operated not according to the hearing or seeing ability of the driver but according to traffic conditions. Thus, there is no failure to recognize the warning and it is possible to significantly reduce the overall response time.
The present invention provides an information device wherein the external force generating means comprises at least one of urging means for supplying a new urging force to the accelerator pedal in a direction to return to a deceleration side, and excitation means for supplying vibration to the accelerator pedal.
If an external signal is received, vibration is applied to the accelerator to be actuated according to traffic conditions. An urging force is applied in a direction to reduce the number of engine revolutions. Thus, the driver recognizes the vibration or a new urging force directly acting on his feet, so there is no failure to recognize the warning and it is possible to significantly reduce the overall response time.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a cross sectional drawing of a throttle grip 1 of a motorcycle according to one embodiment of the present invention.
FIG. 2 is a schematic block diagram of a control system for the information device motor drive.
FIG. 3 is a flowchart of the control sequence of the control system shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described with reference to FIG. 1 to FIG. 3 . This embodiment is an information device applied to a motorcycle.
FIG. 1 is a cross-sectional drawing of a throttle grip 1 of a motorcycle. The throttle grip 1 is a closed cylinder and is supported by being rotatably fitted onto the right side end of a cylindrical handle bar 2 .
The throttle grip 1 is urged in the direction of reducing the engine speed by a spring (not shown). Acceleration is controlled by a twisting actuation against the force of the spring.
A miniature motor 3 is fitted inside the left end of the handlebar 2 , a drive shaft 3 a of the motor 3 protrudes from an opening in the right side of the handlebar 2 . The end of the drive shaft is attached to a centrifugal clutch 4 .
The centrifugal clutch 4 is positioned along the bottom wall of the inside of the throttle grip 1 . The motor 3 rotates the drive shaft 3 a in the direction in which the throttle grip reduces the speed of the engine. The centrifugal clutch 4 rotates in the same direction as the drive shaft 3 a , and expand outwardly so as to come into contact with the inside of the throttle grip 1 and supplies an urging force to the throttle grip 1 in a direction to reduce the engine speed.
The centrifugal clutch 4 is also provided with an eccentric weight so that vibrations are generated due to the rotation of the clutch.
Accordingly, if the motor 3 is driven, an urging force in a direction to reduce the engine speed caused by the centrifugal clutch 4 acts on the throttle grip in addition to the urging force of the spring. A driver holding the throttle grip 1 recognizes this increased urging force and vibrations are conveyed to the driver's hand.
A schematic block diagram of a control system for the information device using the drive of this motor 3 is shown in FIG. 2. A communication control circuit 11 supplies a transmit command to a transmit circuit 12 , and is supplied with a receive signal received by a receive circuit 13 .
The transmit circuit 12 receives a transmit instruction from the communication control circuit 11 and transmits a signal from the transmit antenna 12 a , while the receive circuit 13 receives a signal at the receive antenna 13 a and outputs the signal to the communication control circuit 11 .
Radio signals are used for communication, but it is also possible to use a light beacon or the like.
A signal that the receive circuit 13 has received from a moving body of another party is processed by the communication control circuit 11 , necessary information is output to traffic conditions judging means 14 which analyzes the distance from the moving body of the other part etc., and judges what stage the traffic conditions are at.
Specifically, it is judged whether it is necessary to notify the driver urgently, whether it is not all that urgent, or whether there is no urgency at all.
This judgement result is output to the display 16 and the motor control means 15 . The motor control means 15 judges whether or not it is necessary to decelerate, and the drive of the motor 3 of the throttle grip 1 is controlled.
A schematic diagram of the control sequence of the control system of this invention is shown in FIG. 3 and will now be described. First of all, it is judged whether or not there is a receive signal (step 1 ), and when there is no receive signal this routine is exited and a return is executed to await a receive signal.
If there is a receive signal, the program advances to step 2 , traffic is judged from the received information and it is judged, from a judgement result as to what stage the traffic conditions have reached, whether or not it is necessary to decelerate.
If it is judged that it is necessary to decelerate the program advances to step 4 and the motor 3 is driven, while if it is judged that deceleration is not necessary step 4 is skipped, this routine is exited and the motor 3 is not driven.
By carrying out the control as described above, if the motor 3 is driven by judging from the traffic conditions that deceleration is necessary such as at the time of an emergency or the like, the driver can be made to feel the vibration and a spring force in the direction of deceleration acting on the throttle grip 1 that he is holding, there is no failure to recognize this warning and deceleration is prompted.
Accordingly, the driver feels the warning with his hands caused by the spring force of the throttle grip 1 and the vibration and it is reliably recognized, and it is possible to prevent the failure to recognize the warning.
Also, a deceleration operation carried out by the driver is preferably an operation following the direction in which the spring force acts, and so there is no failure with respect to the judgment or operation.
In order to decelerate, information is conveyed directly to the hands of the driver not from what the driver sees or hears but from the throttle grip 1 that is to be operated.
Since the manual operation is prompted, it is possible to easily reduce the overall reaction time from when the driver recognizes the information until the operation is carried out.
The judgement result from the traffic conditions judging means 14 is also output to the display 16 , which means that in situations requiring an urgent display such as providing a flashing display lamp the fact that it is necessary to decelerate is also made visually recognizable.
It is also possible to use an audible alert such as a buzzer.
Here, the motor control means 15 varies the rotational speed of the motor 3 according to the judgement result from the traffic conditions judging means 14 .
Specifically, in situations such as where a particular urgency is required, the spring force acting on the throttle grip 1 is increased by rotating at a high speed, while where only a degree of urgency is required the spring force is made a suitable force by rotating at an intermediate speed, and in this way the importance of the information can also be conveyed to the driver.
When there is the utmost need for urgency, it is also possible to cause the throttle grip 1 to forcedly rotate in a returning direction against the driver grasping the throttle grip 1 with the normal force maintaining the rotational angle.
In the above described embodiment, the structure is such that a spring force acts directly on the throttle grip 1 , but it is also possible to have such an arrangement that a throttle cable connected to the throttle grip is urged in a direction of throttle closing.
For example, a structure having a clutch attachment disk could be provided on a throttle pulley attached to a carburetor or fuel injection assembly around which the other end of the throttle cable extending from the throttle grip is wound. In this way, a rotation force would be generated by driving the motor.
If the motor is driven and the clutch is controlled to connect in a stepwise manner, the rotational force that controlled the disk causes the throttle cable to be pulled in such a direction that the throttle is closed.
Accordingly, the throttle grip is urged via the throttle cable in a direction to cause deceleration of the vehicle, information is conveyed to the hand of the rider holding the throttle grip, so there is no failure to recognize the information and a manual operation is prompted.
It is also possible to pull the throttle cable in a direction to close the throttle via a spring by using a link acted upon by an electromagnetic force.
Next, in the case of a four wheeled vehicle an air cylinder is attached so as to urge an accelerator pedal in a returning direction, and the air cylinder is connected a compressor via a regulator.
If there is a received signal and it is judged from the traffic conditions that it is necessary to decelerate, the air cylinder is activated, the accelerator pedal is forced in a returning direction, information indicating that there is a need to decelerate is conveyed to the driver's foot that is placed on the accelerator pedal, and deceleration is prompted.
At this time, the regulator is made to operate so that a fixed urging force is applied to the accelerator pedal regardless of the extent to which the throttle is open.
By carrying out this regulator operation in a pulsed manner, the driver can more reliably recognize changes in the pressure applied to the accelerator pedal, and it is possible to reliably convey information while preventing failure to recognize a warning.
If the driver receives this information with his foot, the pressing of his foot is preferably relaxed following an urging force in a direction of returning the accelerator pedal, and it is possible to prevent failures with respect to the judgment or operation and to reduce the overall response time.
In the case of a four wheeled vehicle, in addition to the above, a steering wheel is vibrated in a direction of the rotational axis using a vibrator or the like, and thus information is also conveyed to the driver's hands.
Also, in a vehicle such as a buggy, a throttle lever is provided close to a grip of the steering wheel so as to be operated using a thumb, but it is also possible to have such a structure that an urging force is caused to act on the throttle lever and vibrations are supplied.
If operating means that is operated by the driver's hands or feet controls drive assemblies of the vehicle, external force can be supplied to the operating means according to the present invention.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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To provide an information device that makes it possible to easily reduce the overall reaction time and makes it difficult to overlook a warning. An information device includes an external force generator for supplying external force to an operator touched by the extremities, the hands or feet, of a driver at the time of operation of the vehicle. A judging member is provided for receiving an external signal and judging traffic conditions. A control member controls the driving of the external force generator based on the judgement result of the judging member.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for treating solid materials. More specifically, the present invention describes a method for treating solid materials which imparts a durable antistaticity and durable hydrophilicity to the solid material.
Solid materials such as moldings, sheets, foams, fibers and powders have heretofore been treated with various organic surfactants such as cationic, anionic and nonionic surfactants in order to impart antistaticity and hydrophilicity. However, while such methods do temporarily provide antistaticity and hydrophilicity, they suffer from the drawback of a lack of durability because the coated surfactant is easily removed by water or an organic solvent.
On the other hand, Japanese Pat. No. 44-6069 (69-6069) describes a silicone antistatic in the form of an organo-polysiloxane-polyoxyalkylene copolymer; however, said method again cannot provide a durable antistaticity and durable hydrophilicity because said silicone is easily removed by water or an organic solvent.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for rendering a solid material antistatic and hydrophilic. It is also an object of the present invention to provide a method for providing a durable silicone treatment for a solid material. It is a particular object of this invention to provide a method for conferring hydrophilicity and antistaticity properties to fibers and fiber-containing materials.
These objects, and others which will become apparent upon consideration of the following disclosure and appended claims, are obtained by the method of this invention which, briefly stated, comprises treating a solid material with a composition which comprises, as its principal component, an organo-polysiloxane compound which contains at least one siloxane unit bearing an alkoxysilylalkyl radical and at least one siloxane unit bearing a polyoxyalkylene radical, at least one of which is at the terminal portion of a siloxane chain.
In a preferred embodiment of this invention at least one of the siloxane chain-terminating radicals is an alkoxysilylalkyl radical.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method comprising applying to a solid material a composition comprising an organopolysiloxane compound which contains at least one siloxane unit having the formula X a R.sub.(3-a) SiR'Si(R) b O.sub.(3-b)/2 and at least one siloxane unit having the formula R"(OC 3 H 6 ) c (OC 2 H 4 ) d OR'Si(R) e O.sub.(3-e)/2, any remaining siloxane units in the organopolysiloxane having the formula R f SiO.sub.(4-f)/2 wherein, at each occurrence, X denotes an alkoxy or alkoxyalkoxy radical having from 1 to 4 carbon atoms, R denotes a monovalent hydrocarbon or halogenated hydrocarbon radical having from 1 to 10 carbon atoms, R' denotes an alkylene radical having from 2 to 10 carbon atoms, R" denotes a hydrogen atom or a monovalent organic radical having from 1 to 5 carbon atoms, a has a value of 2 or 3, b has a value of 0, 1 or 2, c has a value of from 0 to 50, d has a value of from 0 to 50, c plus d has a value of from 2 to 100, e has a value of 1 or 2 and f has a value of from 0 to 3, there being, per molecule of said organo-polysiloxane compound, an average of at least one siloxane unit wherein b or e has a value of 2.
By way of explanation, the organopolysiloxane compound of the present invention must contain, in each molecule, an average of at least 1 unit with the formula ##STR1## and an average of at least 1 unit with the formula ##STR2##
The former unit is needed to increase the bonding and affinity to solid materials as well as to provide durability by the condensation reaction of the alkoxy groups at the molecular terminals with an increase in molecular weight. The latter unit is needed to impart antistaticity and hydrophilicity to the solid material.
In the preceding formulae, X is any alkoxy group or any alkoxyalkoxy group having from 1 to 4 carbon atoms and concrete examples thereof are methoxy, ethoxy, propoxy and methoxyethoxy. R' represents any alkylene group having from 2 to 10 carbon atoms and concrete examples thereof are ethylene, propylene, butylene and hexylene. Each R represents any monovalent hydrocarbon group or halogenated monovalent hydrocarbon group having from 1 to 10 carbon atoms and concrete examples thereof are alkyl groups such as methyl, ethyl, propyl and octyl; alkenyl groups such as vinyl, allyl and propenyl; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl and 3,3,3-trifluoropropyl; aryl groups such as phenyl and tolyl and substituted aryl groups. R" represents a hydrogen atom or any monovalent organic group having from 1 to 5 carbon atoms. Concrete examples of said monovalent organic groups are monovalent hydrocarbon groups such as methyl, ethyl, propyl, cyclohexyl, phenyl and β-phenylethyl; acryl groups and the carbamyl group.
In the preceding formulae a is 2 or 3, b is an integer with a value of 0, 1 or 2, c and d both represent integers with values of 0 to 50, (c+d) has a value of 2 to 100 and e is 1 or 2.
Organosiloxane units with formula (1) are exemplified by
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.2 (CH.sub.3)SiO.sub.2/2,
(CH.sub.3 O).sub.2 (CH.sub.3)Si(CH.sub.2).sub.2 (CH.sub.3).sub.2 SiO.sub.1/2,
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 SiO.sub.3/2,
(C.sub.2 H.sub.5 O).sub.2 (C.sub.6 H.sub.5)Si(CH.sub.2).sub.2 (CH.sub.3).sub.2 SiO.sub.1/2,
(C.sub.3 H.sub.7 O).sub.3 Si(CH.sub.2).sub.2 (CF.sub.3 CH.sub.2 CH.sub.2)SiO.sub.2/2, and
(C.sub.4 H.sub.9 O).sub.3 Si(CH.sub.2).sub.3 (C.sub.2 H.sub.5).sub.2 SiO.sub.1/2.
Organosiloxane units with formula (2) are exemplified by
H(OC.sub.3 H.sub.6).sub.20 (OC.sub.2 H.sub.4).sub.20 O(CH.sub.2).sub.3 CH.sub.3 SiO.sub.2/2,
H(OC.sub.2 H.sub.4).sub.10 O(CH.sub.2).sub.5 C.sub.2 H.sub.5 SiO.sub.2/2,
H(OC.sub.3 H.sub.6).sub.15 O(CH.sub.2).sub.3 (CH.sub.3).sub.2 SiO.sub.1/2,
CH.sub.3 (OC.sub.3 H.sub.6).sub.50 (OC.sub.2 H.sub.4).sub.30 O(CH.sub.2).sub.3 (CH.sub.3).sub.2 SiO.sub.1/2,
C.sub.2 H.sub.5 (OC.sub.2 H.sub.4).sub.60 O(CH.sub.2).sub.8 SiO.sub.3/2,
CH.sub.3 CO(OC.sub.3 H.sub.6).sub.25 (OC.sub.2 H.sub.4).sub.15 O(CH.sub.2).sub.6 C.sub.6 H.sub.5 SiO.sub.2/2, and
C.sub.2 H.sub.5 CO(OC.sub.3 H.sub.6).sub.10 (OC.sub.2 H.sub.4).sub.40 O(CH.sub.2).sub.2 CF.sub.3 CH.sub.2 CH.sub.2 SiO.sub.3/2.
Said organopolysiloxane must necessarily contain the two types of units mentioned above. It may be constituted only of those two types of units or it may further contain organosiloxane units having the formula R f SiO.sub.(4-f)/2 wherein f has a value of from 0 to 3. The Si-bonded groups in such other organosiloxane units comprise monovalent hydrocarbon groups, whose concrete examples are as cited for R', above.
The other organosiloxane units are exemplified by
SiO.sub.4/2,
(CH.sub.3).sub.2 SiO,
(CH.sub.3).sub.3 SiO.sub.1/2,
CH.sub.3 SiO.sub.3/2,
(CH.sub.3)(CF.sub.3 CH.sub.2 CH.sub.2)SiO.sub.2/2,
(CH.sub.3)(C.sub.6 H.sub.5)SiO, and
C.sub.6 H.sub.5 (CH.sub.2).sub.2 SiO.sub.3/2.
The organopolysiloxanes that are used in the method of this invention contain at least one terminating siloxane unit having the formula (1) or (2) above. That is to say, the value of b or e must be 2, thereby giving rise to terminating radicals having the formulae
X.sub.a R.sub.(3-a) SiR'Si(R).sub.2 O.sub.1/2 and
R"(OC.sub.3 H.sub.6).sub.c (OC.sub.2 H.sub.4).sub.d OR'Si(R).sub.2 O.sub.1/2.
The molecular structure of said organopolysiloxane is straight chain, branched chain, cyclic or network. The degree of polymerization of, and molar ratio in, said organopolysiloxane are arbitrary; however, they are advantageously determined under the condition that each molecule contain a total of 5 to 500 siloxane units from the stand point of ease of treatment. When the total number of siloxane units is equal to or greater than 50, lubricant properties appear.
In a preferred embodiment of the method of this invention the organopolysiloxane compound has a substantially linear structure with the formula A(R 2 SiO) x (RQSiO) y (RGSiO) z SiR 2 A. In this formula Q denotes the above-noted radical having the formula --R'SiX a R.sub.(3-a), G denotes the above-noted radical having the formula R'O(C 2 H 4 O) d (C 3 H 6 O) c R", A denotes a siloxane chain-terminating radical selected from the group consisting of R, Q and G radicals, x has a value of from 1 to 500, y has a value of from 0 to 100 and z has a value of from 0 to 100, at least one A radical being a Q radical or a G radical. The A radicals can be the same or different, as desired.
To increase the likelihood that substantially all of the molecules in the compound will durably adhere to a solid material when it is applied thereto it is preferred that at least one of said terminating radicals is a Q radical. To assure that substantially all of the molecules in the compound will durably adhere to a solid material when it is applied thereto it is preferred that both of said terminating radicals are Q radicals.
In the above formula the arrangement of the disubstituted siloxane units is not critical; however, it is typically an approximately random arrangement. The arrangement of the siloxane units in the above formula has the conventional meaning and is not to be interpreted as requiring a block type arrangement of siloxane units. Furthermore, although the compounds of this invention are described as having a linear molecular structure, the presence of trace amounts of branching siloxane units having the formulae SiO 3/2 and SiO 4/2 , frequently present in commercial organopolysiloxanes, are contemplated herein.
Concrete examples of the linear compounds used in this invention include, but are not limited to, those shown in the examples disclosed below and the following: ##STR3##
as well as compounds in which one silicon-bonded methyl group at the end of the preceding compounds is changed to phenyl or 3,3,3-trifluoropropyl, compounds in which all or part of the dimethylsiloxane units are changed to methylphenylsiloxane units or methyloctylsiloxane units and compounds in which some or all of the dimethylsiloxane units are changed to methyl(3,3,3-trifluoropropyl)siloxane units. Herein Me, Et, EO and PO denote CH 3 , CH 3 CH 2 , C 2 H 4 O and C 3 H 6 O, respectively.
The organopolysiloxane used by the present invention can be produced, for example, by the addition reaction of an organopolysiloxane with the formula
H.sub.3 C[(CH.sub.3).sub.2 SiO].sub.50 [CH.sub.3 (H)SiO].sub.5 (CH.sub.3).sub.3
with an organosilane with the formula
CH.sub.2 ═CHSi(OCH.sub.3).sub.3
and a polyoxyalkylene with the formula
CH.sub.2 ═CHCH.sub.2 O(C.sub.2 H.sub.4 O).sub.10 (C.sub.3 H.sub.6 O).sub.5 H
in the presence of a platinum-type catalyst.
To use the composition for treating solid materials, said organopolysiloxane can be used alone or it can be dissolved or auto-emulsified in water or emulsified in water using an appropriate emulsifier such as the salt of the sulfate ester of a higher alcohol, alkylbenzenesulfonate salts, higher alcohol-polyoxyalkylene adducts, higher fatty acid-polyoxyalkylene adducts, alkylphenol-polyoxyalkylene adducts and higher fatty acid-sorbitan esters, etc.
Alternatively, the organopolysiloxane can be dissolved prior to use in an organic solvent such as toluene, xylene, benzene, η-hexane, heptane, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, mineral terpene, perchloroethylene or trichloroethylene, etc.
The solid material can be treated by the method of the present invention by spraying, roll coating, brush coating or immersing the solid material. The coating quantity of the agent is arbitrary and depends on the type of solid material treated; however, it is generally 0.01 to 10.0 weight percent based on the solid material. Solid materials coated with the composition of the present invention will have a durable antistaticity and durable hydrophilicity after standing at room temperature or after heating, such as by blowing with hot air.
In addition, the compositions of the present invention may be jointly applied to a solid material with a curing agent such as a silanol curing catalyst such as the zinc, tin or zirconium salts of an organic acid, such as zinc stearate, zinc oleate, dibutyltin diacetate, dibutyltin dioleate, dibutyltin dilaurate or zirconium stearate and/or silanol crosslinking compound such as an alkoxysilane such as an amino group-containing alkoxysilane or an epoxy group-containing alkoxysilane, an organohydrogenpolysiloxane, or a silanol group-containing organopolysiloxane.
Solid materials to which the compositions of the present invention can be applied are exemplified by various fibers and the textiles of said fibers; sheet materials such as paper, natural and synthetic leathers, cellophane and plastic films; foams such as synthetic resin foams; moldings such as synthetic resin moldings, natural and synthetic rubber moldings, metal moldings, glass moldings; and powder materials such as inorganic powders and synthetic resin powders.
The fibers are exemplified by natural fibers such as hair, wool, silk, flax, cotton and asbestos; regenerated fibers such as rayon and acetate; synthetic fibers such as polyester, polyamide, vinylon, polyacrylonitrile, polyethylene, polypropylene and spandex; glass fibers; carbon fibers; and silicon carbide fibers. Fiber forms include staple, filament, tow and yarn. Concrete examples of the textiles are knits, weaves, nonwovens, resin-processed fabrics and their sewn products.
EXAMPLES
The present invention will be explained using examples of execution. "Parts" and "%" in the examples denote "weight parts" and "weight percent", respectively. The viscosity is the value measured at 25° C.
The organopolysiloxanes used in the examples have the following structural formulas. ##STR4##
EXAMPLE 1
Five parts of each of organopolysiloxanes A to E are respectively combined with and dissolved to homogeneity in 995 parts each of toluene to produce treatment liquids (a), (b), (c), (d) and (e).
Five pieces of 65% polyester/35% cotton broadcloth (size, 40×20 cm each) which had been coated with 3% glyoxal-type resin are respectively immersed in these treatment baths for 30 seconds with a 100% mangle expression, allowed to stand and dry at room temperature for 10 hours and then heated in an oven at 150° C. for 5 minutes. The resulting organopolysiloxane-treated fabrics are each cut into 2 pieces. One piece of each organopolysiloxane-treated fabric is washed once in an automatic reversing washer under the following conditions and then rinsed with water twice (under the same washing conditions with the exception that no detergent is used): bath ratio, 1:50; temperature, 40° C.; detergent, 0.5% aqueous solution of New White (from Lion Corporation); washing time, 10 minutes.
To conduct a test of the water absorptiveness, the washed organopolysiloxane-treated fabrics are all laid out flat on filter paper. A drop of water is placed on each fabric using a fountain pen filler in order to measure the time required for diffusion.
An X-ray fluorescence analyzer (Rigaku Corp.) is used to measure the number of counts of silicon on the treated fabrics both before and after washing and the residual organopolysiloxane (%) after washing is calculated from the difference.
The results are reported in Table 1. Fabric treated with the treatment agent of the present invention has an excellent water absorptiveness and also presents an excellent durability on the part of the water absorptiveness with respect to washing.
TABLE 1______________________________________Organo- Treat- Residual Organo-poly- ment Water Absorptiveness polysiloxanesiloxane Bath Pre-Wash Post-Wash After Washing, %______________________________________A (a) 3.0 6.5 51B (b) 4.3 5.5 45C (c) 2.0 4.5 45D (d) 3.5 6.0 48E (e) 3.1 10.5 11None None 12.5 10.0 --______________________________________
EXAMPLE 2
Treatment liquids (a') to (e') are prepared by adding 0.5 part of an aminosilane with the formula
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2 NH.sub.2
and 0.2 part dibutyltin diacetate to each of treatment liquids (a) to (e) prepared as in Example 1.
Broadcloth as described in Example 1 is similarly treated to give organopolysiloxane-treated fabric which is subsequently washed and tested for water absorptiveness and measured for residual organopolysiloxane by the methods described in Example 1.
The results are reported in Table 2. The combined use of the aminosilane further increases the durability of the water absorptiveness against washing.
TABLE 2______________________________________Organo- Treat- Residual Organo-poly- ment Water Absorptiveness polysiloxanesiloxane Bath Pre-Wash Post-Wash After Washing, %______________________________________A (a') 4.5 5.0 60B (b') 5.5 5.0 53C (c') 5.0 5.5 55D (d') 3.5 4.5 52E (e') 5.0 8.5 12______________________________________
EXAMPLE 3
An antistaticity test and an antisoiling test are conducted on organopolysiloxane-treated fabrics treated with treatment baths (a) to (e) of Example 1.
Antistaticity Test
Fabric, untreated or treated with organopolysiloxane and washed or unwashed, is allowed to stand at 20° C./65% RH for 1 week and then rubbed for 60 seconds against a cotton cloth (unbleached muslin No. 3) in a Kyoto University Chemical Research Laboratory rotary static tester at 800 rpm. The triboelectric voltage is immediately measured.
Antisoiling Test
The antisoiling characteristic against oil soiling is measured as followed. An artificial soiling liquid is prepared by adequately grinding and mixing 300 g ASTM No. 1 oil in a mortar with 3 g coal tar, 5 g dried clay powder, 5 g portland cement and 5 g sodium dodecylbenzenesulfonate. Five ml of this artificial soiling liquid and 100 ml of a 0.5% aqueous solution of Marseilles soap are both placed in a 450 ml glass bottle; fabric (5×10 cm), untreated or treated with organopolysiloxane and washed or unwashed, is placed in said glass bottle to which 10 steel balls are then added; and the test fabric is thus immersed and treated at 60° C. for 30 minutes. It is then gently washed with water, dried, washed for 10 minutes with a 0.5% aqueous solution of Marseilles soap in an automatic reversing whirlpool electric washer on "high", rinsed with water and then dried. The reflectance of the resulting test fabric is measured at a wavelength of 550 mμ.
The test results are reported in Table 3. The measured values clearly demonstrate that the treatment agent of the present invention provides the treated fabric with a durable antistaticity and soiling resistance.
TABLE 3______________________________________ Reflectance Triboelectric Voltage, at 550Organopoly- Treatment (V) milli-siloxane Bath Pre-Wash Post-Wash microns, %______________________________________A (a) 880 1030 71B (b) 910 1150 65C (c) 920 1110 68D (d) 850 1070 66E (e) 900 1530 53None None 1650 1610 53______________________________________
EXAMPLE 4
Ten parts of each of organopolysiloxanes A, B, C, D and E are respectively combined with 990 parts each of water followed by thorough agitation to prepare 5 types of treatment baths. A piece (40×20 cm) of a mixed 65% polyester/35% cotton raincoat fabric is immersed in each treatment bath for 1 minute with 100% mangle expression and then allowed to stand and dry at room temperature for 3 days. The resulting organopolysiloxane-treated fabrics are each cut into two 20×20 cm pieces. For each fabric, one of the two pieces is washed and post-treated by the method described in Example 1. The crease resistance (%) of the fabrics is measured on the lengthwise texture by the Monsanto method and the flexural rigidity is measured by the Clark method. The lubricity is determined by touch (slipperiness to the touch) and is scored as follows.
S: Very slippery to the touch.
O: Slippery to the touch.
X: Not slippery to the touch.
The results are reported in Table 4. Fabric treated with the treatment agent of the present invention has an excellent lubricity, crease resistance and flexibility, all of which presented little change after washing.
TABLE 4__________________________________________________________________________ Crease Resistance, Flexural Rigidity, Lubrication (%) (mm)Organopolysiloxane Pre-Wash Post-Wash Pre-Wash Post-Wash Pre-Wash Post-Wash__________________________________________________________________________A S S-O 65 63 52 54B S S-O 63 60 53 55C S S-O 63 62 51 53D S S-O 64 60 53 55E S O-X 64 52 53 60Untreated X X 52 51 63 62__________________________________________________________________________
EXAMPLE 5
Ten parts organopolysiloxane A and 1 part zinc stearate are both dissolved in 89 parts water to prepare a treatment liquid which is subsequently coated using a sprayer on one side of a plasma-processed polyethylene terephthalate film to give an organopolysiloxane coat quantity of 0.2 g/m 2 . The resulting film is dried at room temperature overnight and then heated in an oven at 130° C. for 10 minutes.
For comparison examples, a 10% aqueous solution of organopolysiloxane E and a 10% aqueous solution of a nonionic surfactant (NS-210 from Nippon Oil and Fat Co., Ltd.) are respectively prepared and each is respectively sprayed to give an adhered quantity of 0.2 g/m 2 on one side of the same type of plasma-processed polyethylene terephthalate film followed by drying and heating.
The three treated films are immersed in flowing water for 6 hours and then placed smoothly on the water surface in a thermostatted water bath set at 60°±2° C. for 3 hours with the treated surface down. The features of the films are then inspected. The film treated with organopolysiloxane A, the treatment agent of the present invention, retained its hydrophilicity and the down side of the film was uniformly wetted and was transparent. On the other hand, the down sides of the other two films did not present hydrophilicity, but were adhered with water drops and were cloudy.
EXAMPLE 6
Carbon black powder coated with 1% organopolysiloxane A is prepared as follows. 100 g of a 0.5% aqueous solution of organopolysiloxane A is prepared and combined with 50 g carbon black powder and this is allowed to stand and dry and then heated at 100° C. for 5 minutes.
For the comparison example, carbon black powder is coated with 1% organopolysiloxane E by a similar treatment.
Fifty g of each carbon black are respectively combined with 1 l each of water, stirred for 3 hours, filtered off and then dried.
Five parts of each carbon black powder are separately homogeneously dispersed into an aqueous acrylic emulsion paint to prepare paints. The paint containing the carbon black powder treated with organopolysiloxane A presented a uniform dispersion and no settling while the carbon black powder treated with organopolysiloxane E underwent rapid settling to give a nonuniform dispersion. This shows that the agent for treating solid materials of the present invention imparts a durable hydrophilicity.
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A method for treating a solid material to give it hydrophilic and/or antistatic properties comprises applying a composition containing a silicone compound to the material which has one or more alkoxysilylalkyl groups and one or more polyoxyalkylene groups. In a preferred embodiment the method is used to treat fibers and fiber-containing materials. The composition can further contain a curing agent for the silicone. Emulsion compositions are particularly useful.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to shaft seals, and more particularly to turbine engine shaft seals.
(2) Description of the Related Art
In turbomachinery applications, it is often necessary to provide a seal between a rotating shaft and a housing element. At the seal, the shaft typically has symmetry around a central axis (e.g., the shaft has a cylindrical surface area). The shaft axis is normally coincident with the axis of rotation and with an axis of the housing in which the seal is mounted. However, vibration may induce small local oscillatory excursions of the axis of rotation. Brush and labyrinth seals may have sufficient compliance in their respective bristle packs and labyrinth teeth to accommodate relatively minor excursions. To accommodate greater excursions, there may be a non-rigid mounting of the seal element to the housing. This mounting permits excursions of the shaft axis to radially shift the seal relative to the housing to avoid damage to the seal.
BRIEF SUMMARY OF THE INVENTION
A turbine engine has a rotor shaft rotatably carried within a non-rotating support structure. A seal is carried by the support structure circumscribing the shaft and having a flexible sealing element for sealing with the shaft. A chamber is located between the seal and support structure. A fluid is carried within the chamber and damps radial excursion of a seal axis from a support structure axis. The seal may be a full annulus or may be segmented. The fluid may be contained within one or more elastomeric bladders.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal semi-schematic sectional view of a turbine engine.
FIG. 2 is a partial semi-schematic longitudinal sectional view of a seal system of the engine of FIG. 1 .
FIG. 3 is a partial semi-schematic transverse sectional view of the seal system of FIG. 2 , taken along line 3 — 3 .
FIG. 4 is a partial semi-schematic longitudinal sectional view of an alternate seal system.
FIG. 5 is a partial semi-schematic transverse sectional view of an alternate seal system.
Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
FIG. 1 shows a turbine engine 20 having a housing case 22 containing concentric high and low pressure rotor shafts 24 and 25 . The shafts are mounted within the case for rotation about an axis 500 which is normally coincident with central longitudinal axes of the housing and shafts. The high pressure rotor shaft 24 is driven by the blades of a high pressure turbine section 26 to in turn drive the blades of a high pressure compressor 27 . The low pressure rotor shaft 25 is driven by the blades of a low pressure turbine section 28 to in turn drive the blades of a low pressure compressor section 29 and a fan 30 .
The rotor shafts are supported relative to the case by a number of bearing systems. The rotor shafts may be sealed relative to the case by sealing systems 40 which may include brush sealing elements, labyrinth sealing elements, or the like.
FIG. 2 shows further details of an exemplary sealing system 40 . The exemplary system includes a brush seal 50 having a bristle pack 52 secured in a seal body comprising a pair of backing plates 54 and 56 . The plates 54 and 56 are respectively designated as the side plate and the back plate and sandwich the bristle pack on respective high and low pressure sides thereof. In the exemplary embodiment, the bristle roots are secured between the plates with bristle tips extending inward therefrom to contact the shaft outer surface 60 . Bristle and plate materials are typically various metal alloys such as nickel- or cobalt-based superalloys and the plates and bristle roots may thus be secured by welding. Additional shorter bristles may intervene between the sealing bristles contacting the shaft and the backplate. The tips of these bristles may be closer to the rotor than is the inboard surface of the backplate. Such an arrangement provides additional support to the sealing bristles during true running operation while limiting the chance of damage during a rotor excursion.
The seal 50 is contained within an annular seal backing/mounting ring 62 . The ring 62 includes an annular sleeve portion 64 having interior and exterior surfaces 66 and 68 . On the low pressure side, a short flange 70 extends radially inward from the surface 66 . The seal is accommodated within the ring such that an exterior rim surface 72 of the seal contacts the interior surface 66 while a downstream radial surface of the plate 56 contacts an upstream radial surface of the flange 70 . A retaining ring 74 is captured in a groove in the surface 66 so that a downstream surface of the ring 74 contacts an upstream surface of the plate 56 to sandwich the seal 50 between the plate 74 and flange 70 to firmly retain the seal relative to the mounting ring.
The mounting ring 62 is accommodated within a compartment in the case defined by respective downstream and upstream surfaces 80 and 82 of upstream and downstream walls 81 and 83 and an interior surface 84 of an annular wall 85 . Upstream and downstream rims of the sleeve 64 carry o-rings 90 for sealing with the surfaces 80 and 82 . The mounting ring 62 includes a pair of upstream and downstream seal rings 94 and 96 extending radially outward from the exterior surface 68 . Exemplary seal rings may be similarly formed to split piston rings. They may be formed by a casting and machining process. Hood stress in the seal rings may allow them to maintain engagement with the mounting ring while freely sliding radially within the channels 100 and 102 . Fluid pressure may allow the seal rings to seat axially against radial surfaces of the channels.
Exterior annular rim portions of the rings 94 , 96 are captured within radial channels 100 and 102 in the surface 84 . The channel bases are of sufficiently greater diameter than the sealing ring rims to permit the sealing rings (and thus the mounting ring) a desired amount of radial float relative to the case. The sealing rings and portions of the sleeve 64 and wall 85 between the rings bound a first chamber 120 containing a fluid 122 . Exemplary fluids are oils, water and air. Advantageously in a turbine engine application, the fluid is useful in an operational range of 150° C. to 550° C. (e.g., is non-flammable and does not undergo a phase change or decompose).
The fluid 122 may be introduced to the chamber 120 through a port 124 in the wall 85 . A fluid source may comprise a reservoir 130 such as a sump tank or pressure vessel. To deliver the fluid from the reservoir, a pump 132 is connected to the reservoir via a conduit 134 . The pump is connected to the port 124 via a conduit 136 in which a pressure regulator 138 is positioned. The pressure regulator is in turn coupled to the reservoir via a conduit 140 for returning excess fluid to the reservoir.
In operation, there may be leakage of the fluid around the rings 94 and 96 into chambers 144 and 146 between the sleeve 64 and wall 85 respectively upstream and downstream of the rings 94 and 96 . Ports 50 and 152 are provided in the wall 85 on respective upstream and downstream sides of the rings 94 and 96 to permit a return of leaked fluid from the chambers 144 and 146 to the reservoir via a return conduit system 160 .
FIG. 3 shows exemplary segmenting of the case and seal system. The exemplary case is longitudinally split into two 180° sections along a planar split interface 520 . To maintain the integrity of the ring 62 , its interfaces are provided with shiplap/tongue & groove connections. The seal 50 is split into nominal 90° segments along four planar interfaces 524 . The interfaces 524 are at an off-radial angle so as to be locally parallel to the bristles. The mounting ring 62 is similarly split or may be split in two, similar to the case.
In operation, a radial excursion of the shaft axis relative to the case axis will apply a net force to the bristles. The force is transmitted to the rigid portions of the seal (e.g., the plates and fixed outboard bristle ends. In doing this, the bristles may flex. Advantageously the pump and regulator maintain sufficient fluid pressure that, given fluid viscosity, density, and other properties, permit the fluid to damp radial excursion of the seal induced by the force. It may be possible for the engine control system (not shown) to regulate pressure based upon engine operating conditions to provide a desired degree of damping.
FIG. 4 shows an alternate sealing system 200 . Elements in common with the exemplary sealing system 40 are referenced with like numerals. In this embodiment, the seal 50 is similarly held within a mounting ring 210 . The mounting ring 210 is captured within a channel 212 formed in a housing wall 214 . A flexible annular bladder 216 (e.g., formed of a suitable elastomer) is positioned between an exterior surface 218 of the mounting ring 210 and a base surface 220 of the channel 212 . The bladder contains a fluid 224 . The bladder is coupled via one or more ports 226 in the housing to supply lines 228 from a pump 230 delivering the fluid from a reservoir 232 . A regulator 234 is positioned in the supply lines and has a return line 238 for returning fluid to the reservoir 232 .
In operation, the sealing system 200 could be controlled in a similar fashion to the system 40 . For an excursion of the seal, the bladder will be locally compressed at one diametric location and locally expanded at the opposite location. Thus the elasticity and other properties of the bladder are relevant to the degree of resistance offered to seal excursions. Relative to the system 40 , this elasticity may provide a greater degree of resistance (e.g. a spring constant) to excursion for a given degree of damping. Relative to the system 40 , the system 200 may be particularly useful with compressible fluids. Automated control of fluid pressure in the system 200 may provide a high degree of control of seal support. In such an automated system, speed and vibration (e.g., actual vibration levels measured via proximity probes) parameters could be measured and further control inputs could be provided indicating other conditions of operation (e.g., whether the engine was accelerating or decelerating). At startup conditions, a very low pressure could be applied to permit the seal to accommodate the rotor excursions (known as “critical vibration”) typical at startup. In stable running conditions, higher pressure could be maintained to keep the seal centered. This may be desirable to prevent high cycle vibration (HCV) from affecting the seal. At lower pressures, the seal may be more prone to HCV. It may be possible to use the engine's compressor as a source of high pressure fluid.
FIG. 5 shows an alternate sealing system 300 in which the bladder is itself segmented into four segments or smaller bladders 310 positioned end-to-end circumscribing the shaft. Each exemplary bladder 310 extends around somewhat less than 90° of the shaft. The bladder segments are positioned approximately coincident with segments of the seal 50 and its mounting ring 312 . Each bladder segment is connected via a case port 314 to a common header supply lines and associated equipment as in the embodiment of FIG. 3 . Operation of the system 300 may be generally similar to that of the system 200 . The use of separate bladder segments may tend to further increase the effective spring constant for a given fluid type and pressure, bladder material, and the like. Additionally, there exists a possibility of fully or partially independent control over the pressure in the bladder segments giving rise to the possibility of an active positioning of the seal under automated control.
One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, environmental considerations may influence parameters of seal construction. Similar seals could be used in non-rotating (e.g., static) brush seal applications. In such applications, wear and heat generation may be of less concern than compacting the bristle pack. Such compacting can cause flaring of the bristle tips (brooming) and/or cause the bristles to be permanently deformed the bristle pack inner diameter. Additional features are possible such as a seal anti-rotation features (e.g., dial pins or tabs mounted to the seal and riding in slots in the case). Accordingly, other embodiments are within the scope of the following claims.
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A turbine engine has a rotor shaft rotatably carried within a non-rotating support structure. A seal is carried by the support structure circumscribing the shaft and having a flexible sealing element for sealing with the shaft. A chamber is located between the seal and support structure. A fluid is carried within the chamber and damps radial excursion of a seal axis from a support structure axis. The seal may be a full annulus or may be segmented. The fluid may be contained within one or more elastomeric bladders.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the production of windings of glass thread wound at constant speed, and in the form of tapered windings.
2. Description of the Related Art
Windings of thread are a common means of temporarily storing the thread. The threads can be in different forms: a single thread comprising one twist, twisted threads, etc. They are ultimately fed to textile machines operating at high speed. The thread must be able to be easily unwound while avoiding any friction that could cause a break. In this regard, tapered windings offer a particular advantage compared to other types of windings. In such a winding, the thread, carried along the axis of the winding in the direction of its smallest diameter, moves immediately away from the lateral edge of the spool as soon as a turn pulls away from it. The risk of a turn being held back by an adjacent turn or of the thread rubbing on the lateral edge of the winding is thus very small.
A large number of solutions have been proposed to achieve such windings. They can be produced by winding the thread with a thread guide that moves in a to-and-fro or reciprocal movement parallel to the axis of a tapered support, the latter being rotated by driving rollers initially applied thereto and then applied on the deposited layers of thread.
Some of the known solutions have the object of maintaining the winding speed of the thread approximately constant, despite the continuous variation in diameter of the support on which it is wound. For this it is necessary to make the rotation speed of the support vary so that the thread always encounters a surface whose peripheral speed is approximately constant. Since the support is put in rotation by driving rollers, the maintenance of peripheral speed can be achieved by the alternation of rapid braking and acceleration of said rollers.
A series of solutions using such a process are described in application EP-A-0 343 540, which itself proposes a particular solution.
The difficulties that must be overcome in using such a process are numerous and far from insignificant. Among the latter are the acceleration and braking of the driving rollers that must be perfectly controlled to avoid slipping between the two surfaces in contact. This risk limits the speed at which the thread can be wound; the above-cited document gives an example according to which the speed of the thread is 140 m/min.
Another difficulty is to prevent the pressure that the driving rollers unavoidably exert on the spool from destroying the thread. This is all the more difficult to avoid when the thread is sensitive to friction by its very nature; this is particularly the case with glass threads.
It must also be noted that it is not possible to wind a thread with driving rollers on a support provided with a lateral flange or edge at one of its ends.
Other solutions make it possible to avoid using driving rollers, such as for example the patent U.S. Pat. No. 3,218,004.
This patent describes a process that makes it possible to produce a tapered winding on a cylindrical support provided with a straight lateral flange or edge at each of its ends. This result is achieved by a concomitant variation in the speed of the thread guide and in the rotation speed of the spindle carrying the support. The variation in the speed of the spindle is caused by the variation of the driving torque, itself caused by the variation in the tension of the thread during its winding.
This process has a certain inertia and is applicable only to threads whose mechanical behavior makes it possible to absorb variations in tension, such as wires, but it is not applicable to threads that do not have this ability to absorb such variations in tension, such as glass threads.
SUMMARY OF THE INVENTION
This invention has as an object a process making it possible to obtain directly--from a spinneret from which continuous glass filaments, assembled in the form of a thread, are drawn--a tapered winding of said thread.
This invention has as a further object a process that makes it possible directly to obtain a tapered winding, whether the support on which the thread is wound is cylindrical or tapered.
The above and other objects of the invention are achieved by a process according to which the continuous glass filaments are drawn mechanically from a multiplicity of strings of molten glass coming from orifices of a spinneret, then are coated with a size and gathered into a thread that is carried by a drawing device, and that consists, downstream from this device, in making said thread move to the end of the arm of a dancing roller, then in winding it on a support attached by one of its ends to a rotatably driven spindle, and in distributing the quantity of thread deposited on said support with the help of a thread guide that moves in a reciprocal movement parallel to the axis of said support. A winding tapered over at least part of its height is obtained by giving a constant value to the speed of the thread in the drawing device, by programming the displacement speed of the thread guide and the length of its run, by continuously measuring the difference between the speed at which the thread is drawn, which is constant, and its winding speed, thanks to the displacement of the arm of the dancing roller, and by making the rotation speed of the spindle subject to the difference thus measured so that, for each run of the thread guide, said spindle rotation speed varies between two extreme values that decrease simultaneously from the start to the finish of the winding operation.
The rotation speed of the spindle can be controlled or regulated in different ways. Thus, it can, in real time, be made subject to the displacement of the arm carrying the dancing roller with a PID regulator connected to the motor of said spindle by a motor speed regulator.
It can also be subject to the displacement of the arm carrying the dancing roller with a PID regulator whose regulating parameters are programmed by a controller, said regulator being connected to the motor of the spindle by a motor speed regulator.
It can also be subject to the displacement of the arm of the dancing roller, whose signal is transmitted to a controller which, after conversion and calculation as a function of the programmed parameters, transmits in turn a signal to the speed regulator connected to the motor of the spindle.
To wind a certain layer "n" the rotation speed of the spindle can be controlled, by a motor speed regulator, by a programmed controller, said control being corrected after comparison with the signals transmitted to the controller by the arm of the dancing roller when layers n-1; n-2 . . . n-p are wound.
In the process according to the invention, the displacement speed of the thread guide for winding each layer of thread can vary between at least two extreme values from the start until the finish of the winding operation. Alternatively the speed of the thread guide can vary, for example, between two extreme values v 1 and v 2 for each layer wound from the start of the winding operation until a predetermined layer "n." For layers n+1; n+2 . . . until the end of the winding operation, the speed of the thread guide can stay constant between the points at which it turns back.
The variation of the speed of the thread guide and the concomitant variation of the rotation speed of the spindle thus make it possible to cause the length of thread wound on any part of the winding surface to vary, considered during at least part of the winding operation and located between two parallel planes separated by a centimeter and perpendicular to the axis of said winding, for all or some of the thread layers, depending on the tapered shape desired for the final winding. For convenience, the length of thread wound on the part of the surface defined above will be called "length of thread per centimeter" in the rest of the description. Since the tapered shape can be produced by the programmable parameters alone of the winding operation, the thread can be wound on a cylindrical support as well as on a tapered support. This support can comprise, at one of its ends, a straight lateral edge or a tapered lateral edge. The process according to the invention thus makes it possible, directly from a spinneret, to make different tapered windings of glass thread.
Thus, according to the invention, the speed of the thread guide can stay constant between the points at which it turns back from the beginning to the end of the winding operation. In this case, the thread is wound on a tapered support.
According to the invention, it is also possible to make a tapered winding by winding superposed layers of a thread on a cylindrical support, formed from internal layers wound at the start of the winding operation in which the length of thread wound per centimeter varies from the top to the base of the winding and from external layers exhibiting a constant length of wound thread.
The height of the thread layers whose tapered winding is formed can decrease progressively from the first layers wound on the support up to the layer forming the periphery of said winding.
Thus a tapered winding can be obtained by winding superposed layers whose height decreases progressively from the first layers wound on the selected support winding up to the layer forming the periphery of the winding. Depending on whether the selected support is cylindrical or tapered, the speed of the thread guide varies or stays constant between the points at which said thread guide turns back.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIGS. 1 and 2 diagrammatically show, in lengthwise section, the internal structure of two different windings made according to the invention;
FIG. 3 is a diagrammatic view of an installation making it possible to use the process according to the invention;
FIG. 3a is diagrammatic view of a part of the installation illustrated by the preceding figure; and
FIG. 4 is a diagram of the control device for regulating the devices providing the winding according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process according to the invention can be used within the framework of an installation such as the one illustrated in FIG. 3.
This installation comprises a spinneret 21, shown schematically, which is normally connected to a glass feed source. This source (not shown) can be the forehearth of a furnace that distributes the molten glass to several spinnerets, similar to spinneret 21, fed by gravity. Spinneret 21 can instead be fed with cold glass obtained and stored in the form of balls in a hopper placed above the spinneret.
Spinneret 21 is generally made of platinum-rhodium alloy and is heated by the Joule effect. This spinneret makes it possible to remelt the glass or to keep it at a temperature sufficient for a viscosity suitable for drawing it in the form of continuous filaments. The molten glass flows out of a multiplicity of orifices, such as points 22, and is drawn immediately into a multiplicity of filaments 23, here gathered into a single layer 24. The filaments thus obtained have an average diameter generally between 5 micrometers and 14 micrometers.
This layer 24 comes into contact with the sizing device schematically shown at 25, so that each filament 23 is coated with size. This device 25 is fed continuously with a size that is picked up by the filaments 23, which glide on its surface. The deposited size is preferably made essentially of a mixture of organic products. This makes it possible to avoid the drying operation necessary when using size in the aqueous phase and the drawbacks that result from it. However, it is also possible, within the context of the process according to the invention, to use a size in the aqueous phase. In this latter case, the installation will include a device eliminating most of the water from the size deposited on the thread before it is wound. Such a device is described, for example, in U.S. Pat. No. 5,443,611.
Layer 24 converges toward assembly device 26 where the different filaments are united to produce thread 27. This device can consist of a simple grooved pulley or of a plate provided with a notch. Thread 27, after passing over a guide element 28 such as, for example, a grooved pulley, is carried along at constant speed by device 29 which eliminates speed fluctuations in the thread. This constant speed is generally equal to or greater than 10 meters per second.
The device 29, illustrated schematically in FIG. 3a, consists of a drawing wheel 30 driven by a motor (not shown) which forms a capstan, and by a separating roller 31 turning freely around its axis.
Thread 27 then passes into the groove of a dancing roller 32, turning freely around its axis and attached to the end of an arm 33. At other end 34 of the arm a device, such as a spring 35, gives thread 27 a predetermined tension. As soon as a difference between the drawing speed of wheel 30 and the winding speed of the thread appears, arm 33 pivots around its axis. This movement is immediately detected by a position detector 36.
Thread 27 is then wound with the help of a thread guide such as pulley 37. Pulley 37 is driven with a reciprocal movement between two positions P l and P 2 , and distributes the thread on a support including a core 38 provided at its base with a straight lateral flange or edge 39. This support is fixed on a spindle 40 rotated by a motor 41.
The controller for regulating this installation is shown schematically in FIG. 4.
The controller 100 controls the motor 102 of drawing wheel 30, via motor speed regulator 103, so as to rotate at a constant speed, a condition that must be imperatively satisfied to obtain filaments 23 of constant diameter and thus a thread 27 with a constant titer. The controller 100 also controls the motor of the pulley 37, via the speed regulator 105, so as to give it displacement speed(s) and length of its travel that are maintained throughout the winding operation to obtain a winding of a certain structure. The programming of the length of travel makes it possible, for example, to progressively reduce the travel of the thread guide at the start of the winding operation to obtain the conical shoulder 13 shown in FIGS. 1 and 2. In the case of a winding on a support provided with a tapered lateral flange or edge (FIG. 2), this programming also makes it possible to modify the travel of the thread guide to wind the last turns of each layer at a level slightly less than that reached by the last turns of the preceding layer. It is thus possible to avoid the formation of an undesirable accumulation of turns in the zone at the end of travel of the thread guide. With a support provided with a tapered lateral edge, the winding can be formed solely from layers exhibiting a constant thread length per axial centimeter of the support from one end of the winding to the other.
The movement, or more exactly the rotation, of arm 33 of the dancing roller around its axis, caused by the appearance of a difference between the drawing speed and the winding speed of the thread, is transformed into an electric signal by a position detector 36 such as a potentiometer. This signal is transmitted to a PID regulator 106 having integral and derivative proportional operation. The parameters of this regulator can be established by potentiometers or programmed by the controller. The signal processed by the regulator is transmitted to a motor speed regulator 108 that controls motor 41 of spindle 40. It may be appreciated that when forming a tapered winding the rotating speed of the spindle decreases from the start to the finish of the winding operation, and that the winding speed also decreases as the thread approaches the flange.
The rotation of arm 33 of the dancing roller 32 can also be recorded by an encoder placed on its axis instead of a potentiometer. The signal of the encoder is transmitted to the controller 100. After calculation as a function of the programmed parameters, the information is transmitted to the motor speed regulator 108 that controls motor 41.
The preceding regulation is a reactive regulation in real time as a function of the displacement of the dancing roller 32. Provided there is a more complex programming, it can be of the digital-predictive type with analog corrections.
Thus the controller, after calculation as a function of programmable parameters, transmits a signal to the regulator 108 that controls motor 41. Any rotation of the arm of the dancing roller 32 is thus recorded by the encoder attached on its axis. The signal supplied by the encoder is transmitted to the controller 100. After calculation and correction, the controller transmits a modified signal to the motor regulator, etc.
FIGS. 1 and 2 schematically illustrate two examples of windings of glass thread obtained according to the invention.
The winding of FIG. 1 has the following structure: each of the layers wound after the start of the winding operation exhibits a very large variation in the length of thread wound per centimeter of the length of the support, from the top of the winding up to its base. For example, the thread guide velocity is increased as it moves toward the top of the support. This is symbolized, in zone 13, by a series of layers whose thickness increases greatly from the top of cylindrical barrel 11 to the straight lateral flange or edge 12. This type of winding (i.e., that of zone 13) is performed until the desired tapered shape is obtained for the final winding. The following layers can then have a length of thread wound per centimeter that is constant over their entire height. This is symbolized by layers 14 of constant thickness. In reality, the thickness of these layers is not rigorously constant from the start to the finish of the winding operation. A very slight difference in the conicity of the winding can be observed during its enlargement. Winding 10 also has a conical shoulder 15.
FIG. 2 illustrates another type of winding 16 made on a tapered barrel 17 provided with a tapered lateral edge or flange 18. The wound layers have a length of thread deposited per centimeter that stays constant over their entire height. This is symbolized by layers 19 of constant thickness. This winding also has a tapered shoulder 20.
The accompanying table gives, by way of examples, the characteristics and production parameters for two kinds of tapered windings made according to the invention. These windings were obtained from a thread of 68 tex, formed from 408 glass filaments with an average diameter of 9 micrometers, drawn at 2220 meters per minute. The size deposited on these filaments has the following composition, expressed in percentages by weight:
______________________________________isobutyl stearate 4.25%silicone acrylate (sold under the 14.25%name Ebecryl 1360 by theUnion Chimique Belge company)diacrylate carbonate 14.25%(sold under the name Acticryl CL993 by the Harcros company)N-vinyl pyrrolidone 33.25%ethoxylated trimethylolpropane triacrylate 19.00%(sold under the name SR454 by theCray Vallee company)1-hydroxycyclohexyl phenylketone 10.00%(sold under the name Irgacure 184by the Ciba-Geigy company)ethoxylated trimethoxysilane 5.00%(sold under the name Silane Y 5889by the Union Carbide company)______________________________________
Winding No. 1 was made on a cylindrical barrel provided with a straight lateral edge; winding No. 2 on a tapered barrel also provided with a straight lateral edge. These two windings have a conical shoulder.
TABLE______________________________________Winding No. 1 No. 2______________________________________Cop diameter (mm)top, initial 90 98bottom, initial 90 118top, final 150 188bottom, final 170 196Spindle speed (revolutions/min)top, initial 7852 7211bottom, initial 7852 5989top, final 4711 3759bottom, final 4157 3605Speed of thread guide (m/min)rising, bottom 6 5rising, top 8 5descending, top -12 -10descending, bottom -6 -10Length of thread (in m per cm)*start of windingrising, bottom 3.7 4.4rising, top 2.8 4.4descending, top 1.9 2.2descending, bottom 3.7 2.2end of windingrising, bottom 3.7 4.4rising, top 2.8 4.4descending, top 1.9 2.2descending, bottom 3.7 2.2Travel of thread guide (mm)start of winding 380 375end of winding 230 205Angle of winding (degrees)interior 0.0 1.5exterior 2.5 1.1cone 11.3 14.8Net weight (kg) 7.2 9.5______________________________________ *See definition in the description.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A process for producing tapered windings of glass threads consists, downstream from a drawing device of glass filaments joined into a thread, in making the thread pass to the end of the arm of a dancing roller, then winding it on a support attached by one of its ends to a rotationally driven spindle. The thread is distributed on said support with the help of a thread guide reciprocated in parallel to the axis of said support, so as to obtain a winding tapered over at least part of its height.
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BACKGROUND OF THE INVENTION
This invention relates to an engine driven arc welder, especially to an engine-driven arc welder which may be adjusted in accordance with the characteristics the type of sheathed electrode or the welding position.
Engine driven arc welders weld by creating an arc between the electrode and the material being welded. The power for this comes from a generator driven by an engine, and this power is controlled by a controlling signal and controlling elements.
In arc welding, short-circuits often occur when molten metal or the electrode comes into direct contact with the material being welded. When the welder (operator) goes to re-start the arc after such a short-circuit, if the welder (apparatus) is such that it produces a large current the arc will be easy to re-start, though much sputtering will be produced. On the other hand, if the welder of the type that does not produce a large current in order to ensure better welding quality, it will be difficult to re-start the arc after shorting. This results in the arc cut-off or the electrode sticking the base material. Thus, the welding work may be interrupted if the welder is not so skillful. These kinds of problems are likely to occur particularly when work is carried out in areas where the current is low or when the arc is short.
In the conventional welders in which large current flows during a short-circuit, the arcing can be interrupted the electrode may stick to the base metal and electrode and much spattering may occur, depending on the type of electrode used and the welding position. This is because the characteristic voltage during a transition from a constant current characteristic to an increased current characteristic and the increased fixed current characteristic value for a short circuit are fixed in advance to suit the type of electrodes used in Japan. Even in the case a skilled welder carries out the welding, the appearance of the beads will be less than satisfactory and fine adjustments to the manipulation of the electrode are difficult to carry out, if much sputtering occurs. In addition, when welding is carried out using high cellulose type electrodes, as is often used in overseas countries, it becomes even more difficult to deal with such problems.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an engine-driven arc welder for providing a suitable arc current and short-circuit current required for droplet transfer in accordance with the type of sheathed electrode used and the welding position.
To achieve the above-mentioned object, in accordance with this invention, there is provided an engine driven arc welder comprising: a welding generator driven by engine; an output circuit which controls the output of the welding generator in accordance with a control signal and which delivers this to the welding output terminals; a current detector for detecting the current in the welding output terminals; an error detector which compares the output of this current detector with a reference signal to detect error; a control signal producing circuit which produces the control signal in accordance with output of the error detector and which supplies this signal to the output circuit; and a voltage detector which detects the voltage applied to the welding output terminals. The arc welder has constant current control arc characteristic based on the reference signal and exhibiting a drooping characteristic in the vicinity of arc voltage and is capable of increasing current at the time when the arc voltage is lowered. The arc welder also has an adjustment circuit which determines the magnitude of the reference signal to be delivered to the error detector in accordance with output of the voltage detector. By varying the reference signal the inter-characteristic transfer point between the constant current control arc characteristic and the drooping characteristic can be varied.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing an embodiment of this invention.
FIG. 2a is a partial circuit diagram showing the circuit configuration of the portion for adjusting the welder output characteristics in the circuit showing FIG. 1, and FIG. 2b is a partial circuit diagram showing a modified portion of FIG. 2a.
FIG. 3a is an equivalent circuit diagram of a variable three-terminal regulator, FIG. 3b is control signal voltage--anode/cathode voltage characteristic diagram thereof, and FIG. 3c is a falling characteristic diagram from ON to OFF thereof.
FIG. 4 is a characteristic diagram showing adjustments of output voltage--output current characteristics in the partial circuit of FIG. 2.
FIGS. 5a and 5b are characteristic diagrams showing adjustment to the output voltage--output current characteristic shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a circuit diagram showing the configuration of an embodiment of this invention. In FIG. 1, the main circuit, i.e., output circuit for welding current is shown at the right side in the figure, and its control circuit is shown at the left side thereof.
Further, in the main circuit, the output of the welding generator G is rectified by a mixed bridge circuit of thyristors SCR1-SCR3 and diodes D1-D3 to supply power to the portion between welding electrode and the base material (not shown) from welding output terminals P, N through a reactor L to generate an arc.
Further, the control circuit includes a thyristor drive circuit connected to gates of thyristors SCR in the main circuit (encompassed by double dotted lines), and an error detection circuit. The error detector circuit delivers error signals detected in accordance with the voltage detection signals and the current detection signals in the main circuit to the thyristor drive circuit as a reference signal to be compared with respective phase voltage signals, which are indicated at the periphery of the portion encompassed by double dotted lines indicating the above-mentioned thyristor drive circuit.
The error detection circuit includes an error amplifier EA, and has a positive input terminal supplied with welding current detected by d.c. current transformer CT as voltage signal, and a negative input terminal supplied with respective voltage signals from variable resistors VR1, VR2, a variable three-terminal regulator REG1, a reference voltage forming circuit including a resistor R3 for earth use, and a reference voltage adjustment circuit connected through a diode D10 to this reference voltage forming circuit and operative to adjust its reference voltage. In addition, the minus terminal of the error amplifier EA is fed back to the output terminal through a resistor R1.
The reference voltage forming circuit is composed of: the variable three-terminal regulator REG 1; the variable resistor VR1 for adjusting the arc current; and the variable resistor VR2, resistors R3 to R6, and electrolytic capacitor C1 which adjust the variations of each product. This means that, both ends of anode/cathode of the variable three-terminal regulator REG1 and the electrolytic capacitor C1 are connected in parallel with resistors R5 and R6 in the series circuit of resistors R4, R5 and R6 connected between a circuit power supply +12V and earth (ground), and the control terminal of the variable three-terminal regulator REG1 is connected to the junction of resistors R5 and R6. In addition, the cathode of the variable three-terminal regulator REG1 is earthed (grounded) through resistor R2, the variable resistors VR2, VR1 and the register R3, and the junction of the variable resistor VR1 and the resistor R3 is connected to the minus terminal of the error amplifier EA.
Thus, shared voltage of the resistor R6 in the series circuit of the resistors R4 to R6 is applied at all times to the control terminal of the variable three-terminal regulator REG1. Thus, a constant voltage corresponding thereto is produced across both terminals of anode/cathode thereof. This constant voltage is earthed (grounded) through the resistor R2, the variable resistors VR2, VR1 and the resistor R3, and is given as reference signal with respect to the minus terminal of the error amplifier EA from junction of the variable resistor VR1 and the resistor R3.
The variable three-terminal regulator REG1 produces, across anode and cathode, a voltage approximately proportional to the voltage applied to the control terminal, and can be utilized as a constant voltage element for a control system.
At the same time, the reference voltage adjustment circuit produces voltage output by a photo-coupler PC-1 (which is supplied with power by the voltage response of a voltage dividing circuit (which divides through a resistor R10)) and a variable resistor VR10 and a variable three-terminal regulator REG2, an element similar to the above REG1 which delivers the output voltage to the minus terminal of the error amplifier EA through the diode D10. This means that the divided voltage, received from the voltage dividing circuit that includes the resistor R10 and the variable resistor VR10 which are connected to junctions P', N' of the reference voltage adjustment circuit and output line of the mixed bridge circuit is delivered to the control terminal of the variable three-terminal regulator REG2 through a noise-eliminating CR filter. Thus when a predetermined voltage or more is applied across both terminals of the anode and the cathode of this variable three-terminal regulator REG2, current is caused to flow in the variable three-terminal regulator REG2 to light the light emitting diode of the photo-coupler PC-1 thereby allowing the photo-transistor to be conductive. In this example, the protective circuit for high voltage of the variable three-terminal regulator REG2 is omitted.
Thus, the degree of conduction of the photo-transistor in the photo-coupler PC-1, in which a variable resistor VR20 is connected in series through a protective resistor R20, is controlled in accordance with the quantity of light emitted from the light emitting diode in this photo-coupler. The voltage that the photo-transistor shares by the variable resistor VR20 and the resistors R20 and R3 is delivered to the minus terminal of the error amplifier EA through the diode D10. The minus terminal of the error amplifier EA is earthed by a capacitor for noise elimination.
Further, the plus terminal of the error amplifier EA is supplied with current detection signal from the D.C. current transformer CT which has a built in operational amplifier (not shown), and the current detection signal is compared with reference signal given to the minus terminal. The margin of error obtained between the two signals is passed through a resistor R12 to the plus terminal for inputting the reference signal at comparator CP from the output terminal of the error amplifier EA. Resistor R12 is connected to one end of resistor R11, while the other end of R11 is connected to the circuit power supply.
One terminal of the comparator CP, which receives the input signal to be compared with this reference signal, is supplied with signal corresponding to u-phase voltage of the welding generator G. This means that, the u-phase voltage is delivered to the light emitting diode of the photo-coupler PC-U, and the voltage signal that the photo-transistor forms in accordance with quantity of light emitted is delivered to the minus terminal of the comparator CP. Thus, the comparator CP delivers a corresponding output to the light emitting diode in the photo-coupler PC-O through resistor R13. Further, an energization control signal is delivered from photo-transistor in the photo-coupler PC-O to the gate of the thyristor SCR1 through resistor R14. This means that the thyristor SCR1 is to undergo energization control in accordance with outputs of the error detecting circuit and the thyristor drive circuit which corresponds to output voltage and output current of the mixed bridge circuit.
In this case, although illustration is partially omitted in FIG. 1, similar circuit configurations are also employed for the v-phase and w-phase.
FIG. 2a is a simplified circuit diagram explaining the operation of the error amplifier EA which corresponds to the output voltage detection signal of the mixed bridge circuit in FIG. 1. Junctions P' and N' in the mixed bridge circuit are supplied with welding voltage E (no load voltage V1 to short-circuit voltage VS) applied to welding output terminals P, N.
Voltage obtained by dividing this welding voltage E by voltage dividing ratio between resistor R10 and variable resistor VR10 is delivered to the control terminal of the variable three-terminal regulator REG2. As a result, the voltage corresponding thereto is produced across both terminals of the anode and the cathode terminals of the variable three-terminal regulator REG2. Thus, energization of both light emitting diode in the photo-coupler PC-I and resistor R15 is carried out in the state where voltage obtained by subtracting the variable three-terminal regulator REG2 portion of the voltage across junctions P' and N' is applied thereto. Further, as the result of the fact that energization is carried out through the protective resistor R15, light corresponding to voltage across junctions P' and N' is produced from the light emitting diode, and is delivered to the photo-transistor in the photo-coupler PC-I.
In response to this, the voltage obtained by dividing the voltage of the circuit power supply (+12V) by the photo-transistor, the resistor R20 and the variable resistor VR20, is produced at the photo-transistor of the photo-coupler PC-I. The voltage thus produced is delivered to the minus terminal of the error amplifier EA through diode D10.
In this case, a variable resistor VR20 can be directly inserted between the register R20 and the photo-transistor as shown in FIG. 2a, or it can be used to bridge over the emitter and the collector of the photo-transistor as shown in FIG. 2b.
FIG. 3a shows the equivalent circuit of the variable three-terminal regulator shown in FIGS. 1 and 2a. As apparent from this equivalent circuit, the configuration is such that, when the control signal voltage Vref applied to the control terminal (-) exceeds the constant voltage Vz applied to the reference signal terminal (+), the anode-cathode voltage corresponds to the control signal voltage Vref.
FIG. 3b indicates measured control characteristics, wherein the anode-cathode voltage VA-K is approximately proportional to control signal voltage Vref. The X-axis in this characteristic diagram indicates control signal voltage Vref which is delivered to the control terminal while the Y-axis indicates anode-cathode voltage VA-K.
As for the variable three-terminal regulator REG1, The constant voltage characteristic is obtained by using the region where conductivity is achieved the control signal voltage Vref becomes close to 2.5V in FIG. 3b.
As for the variable three-terminal regulator REG2, the control signal voltage Vref to be delivered to the control terminal is the voltage obtained by dividing the voltage across junctions P' and N' by the voltage divisional ratio by resistor R10 and variable resistor VR10. Voltage VA-K corresponding to this control signal voltage Vref is produced across the anode and the cathode of the variable three-terminal regulator REG2. This voltage VA-K serves as a shared voltage of the variable three-terminal regulator REG2.
FIG. 3c shows the rising characteristic from OFF to ON (falling characteristic from ON to OFF) of the variable three-terminal regulator. This means that the variable three-terminal regulator is almost completely conductive when the anode-cathod voltage VA-K becomes roughly equal to 2.5 V and is almost completely non-conductive when it becomes roughly equal to 1.0 V. This is utilized for output characteristic which will be described later.
FIG. 4 shows the characteristics of changes and details of adjustment in the output voltage and output current of the welder due to resistance value changes in the circuit comprises variable resistor VR10 provided at the light emitting diode side of the photo-coupler PC-I and variable resistor VR20 provided at the photo-transistor side.
The welder of this invention has output characteristic in the constant current characteristics I, III and the drooping characteristic II are combined. In the constant current characteristic, slight drooping characteristic (constant voltage characteristic is also included in the drooping characteristic) is included.
The first constant current characteristic I is obtained as the result of the fact that the minus terminal of the error amplifier EA is kept at constant voltage, as set by variable resistor VR1. Since the photo-transistor in the photo-coupler PC-I is caused to be conductive, namely, is brought into an ON state to be earthed when the arc voltage is large, i.e., V1 to V2, voltage is blocked by the diode D10 and has no effect on the minus terminal of the error amplifier EA. The above-mentioned constant voltage is basically determined by set value of the variable resistor VR1.
The drooping characteristic II is obtained by changes when the photo-transistor in the photo-coupler PC-I is transferred ON to OFF, i.e., changes in the degree of conduction when the photo-transistor in the photo-coupler changes from a conductive state to a non-conductive state based on the falling characteristics from ON to OFF for the variable three-terminal regulator as shown in FIG. 3c. This change is produced when the arc voltage is lowered to some degree, i.e., changes from V2 to V3. The photo-transistor shifts from ON to OFF when the arc voltage is lowered, i.e., falls within the range from V2 to V3. Thus, when collector voltage changes, the voltage corresponding to this change is applied as a reference signal of the minus terminal of the error amplifier EA.
The second constant current characteristic III is obtained by variable resistor VR20 and divided voltage of mainly resistor R3 and variable resistor VR20, which are applied to the minus terminal of the error amplifier EA when the photo-transistor of the photo-coupler PC-I is turned OFF. This is produced when the arc voltage is lowered from V3 to VS.
As stated above, during the time the photo-transistor in the photo-coupler PC-I is turned ON, the reference signal of the error amplifier EA corresponds to the signal based on the first constant current arc characteristic set by the variable resistors VR1, VR2 and the variable three-terminal regulator REG1. In such a case, as the photo-transistor in the photo-coupler PC-I shifts from an ON state to an OFF state, the first constant current characteristic I, the drooping characteristic II and the second constant current characteristic III are combined in accordance with that change. Thus, the characteristic according to this invention is obtained.
Transfer point P1 from the first constant current characteristic I to the drooping characteristic II corresponds to the point where the anode-cathode voltage VA-K in FIG. 3c is about 2.5 V, and transfer point P2 from the drooping characteristic II to the second constant current characteristic III corresponds to the point where the anode-cathode voltage VA-K in FIG. 3c is about 1.0 V.
FIGS. 5a and 5b show adjustment details of the output voltage-output current characteristic shown in FIG. 4, wherein FIG. 5a shows transition of transfer point P1 when inter-characteristic transfer point P1 between the first constant current characteristic portion I and the drooping characteristic portion II is changed, and FIG. 5b shows transition of transfer point P2 when inter-characteristic transfer point P2 between the drooping characteristic portion II and the second constant current characteristic portion III is changed.
The first constant current characteristic portion I is constant or almost constant by current I1 set by variable resistor VR1, and the second constant current characteristic portion III is constant or almost constant at current I2 set by variable resistor VR20. The drooping characteristic portion II is the characteristic portion obtained by connecting the inter-characteristic transfer point P1 of the first constant current characteristic portion I and inter-characteristic transfer point P2 of the second constant current characteristic portion III. The transfer point P1 undergoes parallel displacement as indicated by the portion from ν1 to ν2 of FIG. 5a by adjustment of variable resistor VR10, and the transfer point P2 undergoes parallel displacement as indicated by the portion from ι1 to ι2 of FIG. 5b by adjustment of the variable resistor VR20.
As the result of such adjustment, the first constant current characteristic portion I is constant or almost constant at current I1 by adjustment of the variable resistor VR1. The transfer points P1 and P2 are caused to respectively undergo parallel displacement at the portion from ν1 to ν2 and the portion from ι1 to ι2 by adjustments of the variable resistors VR10 and VR20.
Accordingly, when the first constant current characteristic portion I is set to conform with arc current I1 by variable resistor VR1, one or both of the variable resistors VR10 and VR20 is or are adjusted, thereby making it possible to arbitrarily select inter-characteristic transfer voltage between the first constant current characteristic and the drooping characteristic to be combined therewith and the inter-characteristic transfer current between the drooping characteristic and the second constant current characteristic.
Since the drooping characteristic can be arbitrarily combined with two constant current characteristics of the first constant current characteristic portion I and the second constant current characteristic portion III as stated above, in the case where welding is carried out in the state where arc length is shortened for high cellulose type electrode as commonly used in countries outside Japan, setting of inter-characteristic transfer point P1 to reasonable drooping characteristic and inter-characteristic transfer point P2 to reasonable short-circuit current can be arbitrarily carried out. Thus, satisfactory welding can be carried out with ease. As a result, cutting of arc and/or sticking or securing of the welding electrode and the base material can be prevented, thus making it possible to minimize spattering. For this reason, satisfactory welding can be carried out with good workability.
While this invention relates to welder with phase control of the thyristor as a control element for output control in the above-mentioned embodiment, this invention can be also applied to the welding unit with circuit configured to rectify the output of the welding generator and which contain transistor or IGBT chopper controls that change this rectified output.
The control box for the variable resistors VR1, VR10 and VR20 used for various adjustments in the above-mentioned embodiment, can be provided externally or internally.
In accordance with this invention, as described above, it is possible to provide output characteristics suitable for a wide variety of sheathed welding electrodes. This is because the output characteristic of the arc welder is obtained by connecting the drooping characteristic determined in advance for a certain constant current characteristic by an arbitrary voltage and combining them with each other. Further, one of the two constant current characteristics is made to correspond to the arc current and the other is made to correspond to short-circuit current, and the arbitrary points of both characteristics are connected with the drooping characteristic, thereby making it possible to provide a welder suitable for a wide variety of sheathed welding electrodes.
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An engine driven arc welder including a welding generator driven by an engine; output circuits for controlling the output of the welding generator in accordance with a control signal and for delivering the output to welding output terminals; a current detector for detecting the current flowing in the welding output terminals; an error detector for comparing the output of the current detector with a reference signal to detect error; a control signal producing circuit for producing the control signal in accordance with output of the error detector and for delivering it to the output circuit; and a voltage detector R10, VR10 for detecting voltage to be delivered to the welding output terminals, wherein the arc welder has a welding output characteristic having a constant current control arc characteristic in accordance with the reference signal and which exhibits a drooping characteristic in the vicinity of the arcing voltage and which is capable of increasing the current when the arc voltage is lowered. The engine driven arc welder includes an adjustment circuit VR10, R10, VR20, R20 for determining the magnitude of the reference signal to be delivered to the error detector in accordance with the output of the voltage detector to change the reference signal, thereby allowing the inter-characteristic transfer point between the constant current control arc characteristic and the drooping characteristic to be adjustable.
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BACKGROUND OF THE INVENTION
Cardiotonic agents have been used for the treatment of heart failure for some time with digitalis continuing to be one of the principle pharmacologic agents used for this purpose, although the cardiac glycosides as a class do have some limitations. Cardiac output is regulated by the integration of the contractile state of the heart and the dynamics of the peripheral circulatory system. When the heart fails, the primary problem is impairment of ventricular myocardial contractility which results in inadequate cardiac output to meet the metabolic and circulatory demands of the body. Effective therapy of heart failure is accomplished by either enhancing the contractile state of the heart with positive inotropic agents, or by adjusting the peripheral circulatory state with peripheral vasodilators. Agents which stimulate myocardial contractility are of considerable value in the treatment of heart failure. Conventional therapy for heart failure has been the use of digitalis preparations which are the only orally effective inotropic drugs available for use in the treatment of this condition. However, their peripheral vascular effects are undesirable. Sympathomimetic amines are the other major class of cardiac stimulants which are used for the treatment of heart failure. The use of these agents is likewise limited, because they are not fully effective when administered orally and because of undesirable peripheral vasoconstrictor action. Currently, dobutamine and dopamine are the sympathomimetic agents which are primarily used for heart failure, but they can only be administered parenterally.
Several promising inotropic agents which have been studied clinically are the pyridones, amrinone and milrinone, having the following formula: ##STR3## Amrinone is effective in treating patients with heart failure but its use has been severely restricted to acute use only because it has been associated with a high incidence of serious side effects.
Milrinone is undergoing clinical testing as an inotropic agent and its usefulness has not yet been established.
Because of the limitations of currently available drugs in the treatment of heart failure, there is a clear need for new, effective and safe drugs of this type.
SUMMARY OF THE INVENTION
The present invention is directed to compounds of the formula ##STR4## wherein R is hydrogen, lower alkyl, halo, cyano, hydroxy, amino, lower alkylamino, --CH 2 NH 2 , CH 2 OH or COOR"; R' is hydrogen, lower cycloalkyl or lower alkyl; R" is lower alkyl or CH 2 Ar wherein Ar is phenyl, substituted phenyl, furan or thiophene; R'" is COOR", ##STR5## and x is oxygen or nitrogen; or a pharmaceutically acceptable salt thereof, and their use in the treatment of cardiac disorders, and in particular, in providing a positive inotropic effect in the treatment of impaired ventricular myocardial contractility.
The term "lower alkyl" as used herein refers to straight or branched chain alkyl radicals containing from 1 to 6 carbon atoms including but not limited to methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, 2-methylhexyl, n-pentyl, 1-methylbutyl, 2,2-dimethylbutyl, 2-methylpentyl, 2,2-dimethylpropyl, n-hexyl and the like.
The term "lower cycloalkyl" as used herein refers to cyclic saturated aliphatic radicals containing 3 to 6 carbon atoms in the ring, such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.
The term "halo" includes chloro, fluoro, bromo and iodo.
The term "substituted phenyl" represents phenyl which may be substituted with lower alkyl, halo, hydroxy, alkoxy or amino.
The term "pharmaceutically acceptable salts" includes nontoxic acid addition salts of the compounds of the invention which are generally prepared by reacting the free base with a suitable organic or inorganic acid. Representative salts include the hydrochloride, hydrobromide, sulfate, bisulfate, acetate, oxalate, valerate, oleate, palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, and like salts. Also included are metallic salts such as the sodium or potassium salt of the acid.
The present compounds may be administered to warm-blooded animals orally or parenterally. They can generally be administered with a pharmaceutical carrier. The term "pharmaceutical carrier," for the purpose of the present invention, is intended to refer to any medium that is suitable for the preparation of a dosage unit form, and, thus, includes the tablet medium or a pharmaceuticaly acceptable vehicle or solvent such as is ordinarily used in the preparation of intravenous or intramuscular solutions.
A pharmaceutical composition containing the compound can be administered to warm-blooded animals in parenteral or oral dosage form. For parenteral administration, amounts of from about 10 to 100 mg/kg per day per patient are useful, with the total dose of up to 0.2 to 2 grams per day being a suitable range for large animals, including humans. A preferred dosage range is from about 1 to 10 grams total daily dosage in a single or divided dose.
For all dosage forms the above exemplified compounds can be placed in capsules, formulated into pills, wafers, or tablets in conventional fashion together with pharmaceutical carriers well known in the art. Tablets may be prepared for immediate release of the active compound or there may be made enteric, i.e., whereby the active ingredient is released slowly over a period of several hours from within the intestinal tract.
DETAILED DESCRIPTION OF THE INVENTION
In order to illustrate the manner in which the above compounds may be prepared and the properties of the compounds, reference is made to the following examples, which, however, are not meant to limit or restrict the scope of the invention in any respect.
In the following examples, melting points were obtained on a Thomas-Hoover melting point apparatus and are uncorrected. NMR spectra were obtained on a Varian T-60A spectrometer. IR spectra were obtained on a Perkin-Elmer 283 spectrometer. Examples 1 through 5 describe the preparation of intermediates:
EXAMPLE 1
Ethyl ethoxymethyleneacetoacetate (1)
Using the procedure of Crombie et al., Journ. of Chem. Soc. Perkin Trans. 1, 464-471 (1979), a solution of ethyl acetoacetate (26 g, 0.20 mol), triethyl orthoformate (29.6 g, 0.20 mol) and acetic anhydride (41 g, 0.40 mol) was refluxed for 90 minutes. Distillation under reduced pressure gave the product (1): 26 g, 70% yield; bp=85°-98° C. at 0.5 mm Hg (The following value is reported in the Crombie et al. publication: bp=85° C. at 0.25 mm Hg); NMR (CDCl 3 ) δ 1.2-1.5 (m,6H), 2.4-2.5 (d,3H), 4.0-4.6 (m,4H), 7.7 (d,1H). The signals were split into pairs of closely spaced lines indicative of the cis and trans isomers.
Using the method of Example 1, the following intermediates were prepared.
EXAMPLE 2
Methyl methoxymethyleneacetoacetate (2)
From methyl acetoacetate (30.2 g, 0.26 mol), trimethyl orthoformate (26.7 g, 0.18 mol) and acetic anhydride (53 g., 0.52 mol): 4.3 g, 15%; bp=100°-105° C. at 0.5 mm Hg (lit. 1 80°-84° C. at 0.15 mm Hg); NMR (CDCl 3 ) δ 2.4 (d, 3H), 3.8 (d, 3H), 4.1 (s, 3H), 7.6 (d, 1H).
EXAMPLE 3
Isopropyl ethoxymethyleneacetoacetate (3)
From isopropyl acetoacetate (28.8 g, 0.20 mol) which can be made by the process described by Lawesson et al., Organic Synthesis, Coll. Vol. V, 155-157 (1973), triethyl orthoformate (29.6 g, 0.20 mol) and acetic anhydride (41 g, 0.40 mol): 14.3 g, 35.7%; bp=85°-90° C. at 0.20 mm Hg; NMR (CDCl 3 ) δ 1.3-1.6 (m, 9H), 2.3-2.6 (d, 3H), 4.1-4.5 (m, 2H), 5.0-5.4 (m, 1H), 7.6-7.8 (d, 1H).
EXAMPLE 4
Benzyl ethoxymethyleneacetoacetate (4)
From benzyl acetoacetate (38.4 g, 0.20 mol), triethyl orthoformate (29.6 g, 0.20 mol) and acetic anhydride (41 g, 0.40 mol): 10.7 g, 21.5%; bp=170°-183° C. at 0.5 mm Hg; NMR (CDCl 3 ) δ 1.0-1.4 (t, 3H), 2.2-2.3 (d, 3H), 4.0-4.4 (q, 2H), 5.2 (d, 2H), 7.4 (s, 5H), 7.8-8.0 (d, 1H).
EXAMPLE 5
Ethoxymethyleneacetylacetone (5)
From acetylacetone (20 g, 0.20 mol), triethyl orthoformate (29.6 g, 0.20 mol) and acetic anhydride (41 g, 0.40 mol): 19.3 g, 62%; bp=95°-110° C. at 0.3 mm Hg; NMR (CDCl 3 ) δ 1.3-1.6 (t, 3H), 2.4 (d, 6H), 4.3-4.5 (q, 2H), 7.8 (d, 1H).
EXAMPLE 6
Ethyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (6)
Following the procedure described by Sunthankar et al., Indian Journ. of Chem. 11 (12), 1315-1316 (1973), to a solution of sodium metal (2.3 g, 0.1 g-atom) in ethanol (50 ml) was added slowly with stirring an ethanolic solution (200 ml) of cyanoacetamide (8.4 g, 0.1 mol). The reaction mixture was stirred for about 5 minutes, after which an ethanolic solution (20 ml) of compound 1 (18.6 g, 0.1 mol) was added. The mixture was stirred for 10 minutes during which time it became turbid, yellow and warm. The mixture was refluxed for 45 minutes. Ethanol was then removed under reduced pressure leaving the yellow sodium salt residue. This was dissolved in 50 ml water (with heating) and acidified with 6N HCl to pH 2-3 in an ice bath. The off-white solids that precipitated out were filtered and washed with cold water until the filtrate was no longer acidic. The cyclization was done by refluxing the solids in 600 ml of 95% ethanol for two hours. After cooling to room temperature for 18 hours, white crystals precipitated out. These were filtered and washed with cold ethanol. More of the product was obtained by concentrating the filtrate under reduced pressure. A total of 11.5 g (56% yield) was obtained: mp=214°-216° C.; NMR (DMSO-d 6 ) δ 1.3-1.5 (t, 3H), 2.7 (s, 3H), 3.2-3.3 (NH), 4.1-4.5 (q, 2H), 8.5 (s, 1H); IR (KBr) 2220 cm -1 (CN), 1640-1710 cm -1 (C=O of pyridone and ester).
The following compounds were prepared in a manner similar to that described in Example 6.
EXAMPLE 7
Methyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (7)
From cyanoacetamide (0.02 mol), sodium metal (0.02 g-atom) in MeOH (20 ml) and 2 (0.02 mol): 0.8 g, 21% yield; mp=281°-283° C. (decomposed); NMR (DMSO-d 6 ) δ 2.6 (s, 3H), 3.2 (NH, OH), 3.8 (s, 3H), 8.4 (s, 1H); IR (KBr) 2220 cm -1 (CN), 1650 cm -1 (C=O of pyridone), 1700-1720 cm -1 (C=O of ester).
EXAMPLE 8
Isopropyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (8)
From cyanoacetamide (0.032 mol), sodium isopropoxide (0.032 mol) and 3 (0.032 mol): 1.3 g, 18% yield; mp=237°-8° C.; NMR (DMSO-d 6 ) δ 1.2-1.4 (2s, 6H), 2.6 (s, 3H), 3.2-3.4 (NH), 4.8-5.2 (m, 1H), 8.4 (s, 1H); IR (KBr) 2220 cm -1 (CN), 1660 cm -1 (C=O of pyridone), 1700 cm -1 (C=O of ester). The NMR showed presence of approximately 20-25% of the compound of Example 6.
EXAMPLE 9
n-Butyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (9)
Mp 183°-185° C.
EXAMPLE 10
sec-Butyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (10)
Mp 228.8° C.
EXAMPLE 11
Isobutyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (11)
Mp 192.9° C. (decomposed).
EXAMPLE 12
Isopentyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (12)
Mp 203.2° C. (decomposed).
EXAMPLE 13
n-Octyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (13)
Mp 162.9° C.
EXAMPLE 14
Cyclopentyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (14)
Mp 248.4° C. (decomposed).
EXAMPLE 15
Cyclohexyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (15)
Mp 233.8° C. (decomposed).
EXAMPLE 16
Cyclopropylmethyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (16)
Mp 203.6° C. (decomposed).
EXAMPLE 17
Cyclohexylmethyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (17)
Mp 235.1° C. (decomposed).
EXAMPLE 18
2-Furylmethy 3-cyano-6-methyl-2-pyridone-5-carboxylate (18)
Mp 191.2° C. (decomposed).
EXAMPLE 19
(3-Methyl)-benzyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (19)
Mp 213° C. (decomposed).
EXAMPLE 20
(4-Trifluoromethyl)benzyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (20)
Mp 221.2° C.
EXAMPLE 21
5-Acetyl-3-cyano-6-methyl-2-pyridone (21)
From cyanoacetamide (0.02 mol), sodium metal (0.02 g-atom) in MeOH (10 ml), and 5 (0.02 mol): 1.0 g, 28% yield; mp=233°-4° C.; NMR (DMSO-d 6 ) δ 2.5 (s, 3H), 2.6 (s, 3H), 8.8 (s, 1H); IR (KBr), 1660 cm -1 (C=O of pyridone), 1690 cm -1 (C=O of ketone).
EXAMPLE 22
Benzyl 3-cyano-6-methyl-2-pyridone-5-carboxylate (22)
Using the method described by Hawaldar et al., Indian Journ. of Chem., Sect. B, 19B (2), 151-152 (1980) a mixture of compound 4 (2.5 g, 0.01 mol), cyanoacetamide (0.84 g, 0.01 mol), triethylbenzylammonium chloride (TEBA, 1.1 g 0.005 mol) and 50% NaOH solution (2 ml) was stirred for about 4 hours. The reaction was exothermic and became bright orange. The initially clear solution immediately solidified. A small amount of water was added to facilitate stirring. The mixture was then acidified with 6N HCl, the solids filtered and washed with water and methanol (MeOH) successively. A total of 0.94 g (35%) of off-white solids was obtained: mp=265°-270° C.; NMR (DMSO-d 6 ) δ 2.6 (s, 3H), 3.2-3.5 (NH), 5.4 (s, 2H), 7.4 (s, 5H), 8.6 (s, 1H); IR (KBr) 2240 cm -1 (CN), 1660 cm -1 (C=O of pyridone), 1730 cm -1 (C=O of ester).
EXAMPLE 23
3-Cyano-6-methyl-2-pyridone-5-carboxylic acid (23)
This compound was synthesized in the same manner as the compound of Example 22 from cyanoacetamide (0.01 mol), TEBA (0.005 mol), 1 (0.01 mol) and 50% NaOH solution (2 ml). A more efficient method of preparing this compound was refluxing the compound 6 (0.3 g, 1.5 mmol) with NaOH solution (1 ml, 50%) for 1 hour. White solids precipitated out when the solution was acidified with 6N HCl to pH=1. These solids were filtered, washed thoroughly with water and dried to give 0.24 g (90% yield) of the product: mp=285°-287° C. with decomposition; NMR (DMSO-d 6 ) δ 2.6 (s, 3H), 8.4 (s, 1H); IR (KBr) 2220 cm -1 (CN), 1640-1660 cm -1 (C=O of pyridone), 1710 cm -1 (C=O of carboxylic acid).
EXAMPLE 24
3-(Methoxycarbonyl)-5-(ethoxycarbonyl)-6-methyl-2-pyrone (24a) and 3-(Methoxycarbonyl-5-(ethoxycarbonyl)-6-methyl-2-pyridone (24b)
Using the procedure described by Baker et al., Journ. of Chem. Soc. Perkin Trans. 1, 3, 677-685 (1979), ethyl cyanoacetate (3.5 g, 0.031 mol) was added to NaOMe solution (prepared from 0.72 g of sodium metal in 50 ml of MeOH), followed by 1 (5.77 g, 0.031 mol). The mixture was refluxed for 15 minutes, cooled and divided into two equal parts. The first portion was acidified with 2N HCl to pH 2-3 and extracted with CH 2 Cl 2 . The extracts were washed, dried over MgSO 4 , and evaporated to give an orange-colored solid. After decolorizing with Nuchar activated carbon in ethyl acetate and recrystallizing from EtOAc-hexane, white, fluffy crystals, of 3-(methoxycarbonyl)-5-(ethoxycarbonyl)-6-methyl-2-pyrone were obtained: 0.22 g, 6% yield; mp=94°-96° C.; NMR (DMSO-d 6 ) δ 1.2-1.5 (t, 3H), 2.7 (s, 3H), 3.8 (s, 3H), 4.1-4.6 (q, 2H), 8.5 (s, 1H); IR (KBr) 1700-1730 cm -1 (C=O of Me and Et ester), 1770 cm -1 (C=O of pyrone).
The second portion was treated with glacial acetic acid (0.8 ml) and refluxed for 2 hours. Some solids which formed during the reaction were filtered off. The filtrate was acidified with 6N HCl to pH=1-2, precipitating out the desired pyridone as an orange solid. Purification of this solid with Nuchar activated carbon and recrystallization from MeOH-ether gave white, fluffy crystals of 3-(methoxycarbonyl)-5-(ethoxycarbonyl)-6-methyl-2-pyridone: 0.15 g, 4% yield; mp=200°-202° C.; NMR (DMSO-d 6 ) δ 1.2-1.5 (t, 3H), 2.6 (s, 3H), 3.8 (s, 3H), 4.1-4.4 (q, 2H), 8.6 (s, 1H); IR (KBr) 1660 cm -1 (C=O of pyridone), 1700-1710 cm -1 (C=O of ester).
EXAMPLE 25
3,5-Bis-ethoxycarbonyl-6-methyl-2-pyridone (25)
Ethylcyanoacetate (2.26 g, 0.02 mol) was added to a NaOEt solution (prepared from 0.46 g of sodium metal in 50 ml EtOH), followed by compound 1 (3.72 g, 0.02 mol). The solution was refluxed for 12 hours. Shiny, light-yellow crystals precipitated out after 18 hours of standing at room temperature. After decolorizing with Nuchar activated carbon, white crystals of 3,5-bis-ethoxycarbonyl-6-methyl-2-pyridone were obtained: 1.45 g, 29% yield; mp=195°-197° C.; NMR (DMSO-d 6 ) δ 1.1-1.5 (t, 6H), 2.6 (s, 3H), 4.1-4.5 (q, 4H), 8.6 (s, 1H), 12.6 (NH); IR (KBr) 1660 cm -1 (C=O of pyridone), 1700 cm -1 and 1720 cm -1 (C=O of ester).
EXAMPLE 26
Ethyl 3-cyano-6-methyl-2-pyridone-4-carboxylate (26)
Based on the method described by Fuchs et al., Chem. Abst., 72, 100533 f (1970), a solution of sodium metal (1.15 g, 0.05 g-atom) in ethanol (32 ml) was added to acetone (2.9 g, 0.05 mol) and diethyloxalate (7.31 g, 0.05 mol) in ethanol (10 ml), followed by cyanoacetamide (2.77 g, 0.033 mol) in water (15 ml). The solution was heated on an oil bath at 60°-70° C. for 30 minutes with constant stirring. The solvent was removed under reduced pressure giving an orange solid which was dissolved in a small amount of water and acidified with 6N HCl to pH=2, giving a yellow solid. After filtering and drying, a crude yield of 5.4 g (79%) was obtained. Decolorizing with Nuchar activated carbon gave light-yellow, needlelike crystals: 2.52 g, 24% yield; mp=215°-217° C.; NMR (DMSO-d 6 ) δ 1.2-1.5 (t, 3 H), 2.4 (s, 1H), 4.2-4.6 (q, 2H), 6.6 (s, 1H); IR (KBr) 2240 (cm -1 (CN), 1640 cm -1 (C=O of pyridone), 1720 cm -1 (C=O of ester).
EXAMPLE 27
3-(N-imidazolyl-carbonyl)-6-methyl-2-pyridone (27)
To 4 g (0.026 mol) of 6-methyl-2-pyridone-3-carboxylic acid in 25 ml DMF was added 5.3 g (0.033 mol) of carbonyldiimidazole. The mixture was heated to 55° C. with stirring for 2.5 hours. Bubbles and off-white precipitate were observed during this period. After filtering the solids, washing thoroughly with THF and drying in the vacuum dessicator for 18 hours, 4.7 g (89%) of the product was obtained: mp=237°-239° C. with decomposition; NMR (DMSO-d 6 ) δ 2.3 (s, 3H), 3.4 (NH), 6.2-6.4 (d, 1H), 7.1 (d, 1H), 7.6 (d, 1H), 7.8-8.0 (d, 1H), 8.2 (d, 1H); IR (KBr) 1660 cm -1 (C=O), 1700 cm -1 (C=O).
EXAMPLE 28
5-(-N-imidazolyl-carbonyl)-2-pyridone (28)
6-Hydroxy-nicotinic acid (8.0 g, 0.06 mol) and carbonyldiimidazole (12.0 g, 0.074 mol) were heated at 55° C. for 4 hours in 50 ml DMF. After filtering and washing with ether and water, light-beige crystals of product were obtained: 4.2 g, 38% yield; mp=200°-200.5° C.; NMR (DMSO-d 6 ) δ 6.4 (d, 1H), 7.2 (s, 1H), 7.6-8.1 (m, 3H), 8.4 (s, 1H); IR (KBr) 1600 cm -1 , 1650-1680 cm -1 (C=O of pyridone and imidazolide).
EXAMPLE 29
5-(-N-imidazolyl-carbonyl)-3-cyano-6-methyl-2-pyridone (29)
To 0.20 g (1.1 mmol) of 11 in 10 ml DMF was added carbonyldiimidazole (0.223 g, 1.4 mmol). The solution was stirred for 24 hours at room temperature. Dimethylformamide was stripped off under reduced pressure giving an oil which crystallized upon further drying. The solid was washed with water and dried in the vacuum dessicator. Yellow solids were obtained: 0.11 g, 40% yield; mp=237°-238° C. with decomposition; NMR (DMSO-d 6 ) δ 2.5 (s, 3H), 7.2 (d, 1H), 7.8 (d, 1H), 8.4 (2s, 2H); IR (KBr) 1670 cm -1 (C=O of pyridone), 1710 cm -1 (C=O of imidazolide).
EXAMPLE 30
5-(4,4-Dimethyl-2-oxazolin-2-yl)-2-pyridone (30)
2-Methyl-2-amino-1-propanol (0.94 g, 0.011 mol) and compound 29 (2.0 g, 0.011 mol) were refluxed for 12 hours in 100 ml DMF. The solvent was stripped off giving an oil which was washed with ether and CH 2 Cl 2 and further dried under reduced pressure. Thionyl chloride (10 ml) was then added to the oil and the mixture stirred for 30 minutes. The thionyl chloride suspension was added dropwise to 100 ml of 15% NaOH, cooled in an ice-bath, and more base was added until pH reached 7-8. Insoluble materials were filtered off. The filtrate was extracted with CH 2 Cl 2 (2×50 ml) and the organic extract was separated out, dried over MgSO 4 and concentrated to an oil, which crystallized on standing. Trituration with EtOAc removed the yellow color and gave 0.49 g (23% yield) of white crystalline solid: mp=172°-173° C.; NMR (DMSO-d 6 ) δ 1.4 (s, 6H), 4.0 (s, 2H), 6.5-6.7 (d, 1H), 8.0-8.2 (m, 2H); IR (KBr) 1600 cm -1 , 1650-1680 cm -1 (C=O of pyridone and C=N).
EXAMPLE 31
Ethyl 2-pyridone-5-carboxylate (31)
To 6-hydroxynicotinic acid (1.0 g, 7.19 mmol) suspended in absolute ethanol (EtOH) (10 ml) was added dropwise SOCl 2 (0.55 ml, 7.5 mmol). The reaction mixture was warmed at reflux for 4 hours and concentrated under reduced pressure. The white solid obtained was stirred in hexanes, filtered, and dried to give the product as the hydrochloride salt (1.38 g, 94%), mp=117°-124° C., NMR (DMSO-d 6 ) δ 1.45 (t, J=7 Hz, 3H), 4.27 (q, J=7 Hz, 2H), 6.35-8.17 (m, 3H).
Employing the above described procedure and starting with the appropriate alcohol, the following compounds were prepared.
EXAMPLE 32
Methyl 2-pyridone-5-carboxylate (32)
Mp 169°-170° C.; NMR (DMSO-d 6 ) δ 3.8 (s, 3H), 6.45 (d, 1H), 7.91 (m, 2H).
EXAMPLE 33
Isopropyl 2-pyridone-5-carboxylate (33)
Mp 123°-127° C.; NMR (DMSO-d 6 ) δ 1.29 (d, ,6H), 5.07 (bm, 1H), 6.38 (d, 1H), 7.87 (m, 2H).
EXAMPLE 34
Ethyl 3-cyano-5,6-dimethyl-2-pyridone-4-carboxylate (34)
Using the method of Example 26, a solution of NaOEt was prepared by dissolving sodium (1.15 g, 50 mmol) in absolute EtOH (50 ml). This solution plus an EtOH (2 ml) wash was added to a solution of methylethyl ketone (4.5 ml, 50 mmol) and diethyl oxalate (6.8 ml, 50 mmol) in EtOH (15 ml). A solution of cyanoacetamide (2.77 g, 33 mmol) in water (15 ml) was added and the reaction mixture warmed at 65° C. for 35 minutes. The reaction mixture was concentrated under reduced pressure, taken up in H 2 O (250 ml), filtered, and the filtrate acidified with 6N HCl. Filtration afforded a mixture of the 5,6-dimethyl and 6-ethyl compounds. From the filtrate the product crystallized (400 mg, 6%) as a bright yellow solid, mp=172°-176° C., NMR (DMSO-d 6 ) δ 1.33 (t, J=7 Hz, 3H), 1.92 (s, 3H), 2.33 (s, 3H), 4.42 (q, J=7 Hz, 2H), IR (KBr) 2230, 1740, 1650 cm -1 .
Employing the procedure of Example 22 and starting with the appropriate ketone, oxalate, alkoxide, and alcohol, the following compounds were prepared.
EXAMPLE 35
Ethyl 3-cyano-6-cyclopropyl-2-pyridone-4-carboxylate (35)
Mp 210°-212° C.; NMR (DMSO-d 6 ) δ 1.33 (t, J=7 Hz, 3H), 1.17 (m, 4H), 2.01 (m, 1H), 4.38 (q, J=7 Hz, 2H), 6.35 (s, 1H); IR (KBr) 2230, 1725, 1640 cm -1 .
EXAMPLE 36
Methyl 3-cyano-6-methyl-2-pyridone-4-carboxylate (36)
Mp 233°-234° C.; NMR (DMSO-D 6 ) δ 2.35 (s, 3H), 3.92 (s, 3H), 6.58 (s, 1H); IR (KBr) 2230, 1740, 1670 cm -1 .
EXAMPLE 37
Isopropyl 3-cyano-6-methyl-2-pyridone-4-carboxylate (37)
Mp 216.9° C. (dec); NMR (DMSO-d 6 ) δ 1.33 (d, J=6 Hz, 6H), 2.33 (s, 3H), s.15 (m, 1H), 6.50 (s, 1H); IR (KBr) 2230, 1735, 1650 cm -1 .
EXAMPLE 38
sec-Butyl 3-cyano-6-methyl-2-pyridone-4-carboxylate (38)
Mp 158.7° C.
The described compounds are active inotropic or cardiotonic agents. They have been found to increase the contractile force of the heart while having minimal effects on blood pressure and heart rate and can be used in treating patients with diseased hearts for the purpose of increasing cardiac efficiency through a selective increase in the cardiac contractile force.
The cardiotonic activity of the compounds was established using the following test procedure:
Male Hartley strain guinea pigs (250-500 g body weight), obtained from Hilltop Lab Animals (Scottdale, PA), were stunned by a blow to the head and the left atria removed and rinsed in a modified Kreb's-Henseleit buffer. The buffer was continuously gassed with 95% oxygen and 5% carbon dioxide and was composed of the following: NaCl, 118 mM; KCl, 4.7 mM; MgSO 4 , 1.2 mM; KH 2 PO 4 , 1.2 mM; CaCl 2 , 1.25 mM; NaHCO 3 , 25 mM; Na 2 EDTA, 0.03 mM and D-glucose, 11 mM. The left atria were pierced through one end of the atrial appendage by a platinum hook connected to a fine gold chain and pierced at the other end of the appendage by a partially shielded platinum hook fixed to a glass rod.
The glass rod and atrium were suspended in a 30 ml water-jacketed tissue bath containing the Kreb's buffer at 33° C. Also connected to the glass rod was a second shielded platinum wire which was adjusted so that a 3-5 mm length of an unshielded portion of the wire was in contact with the atrium very near to the first shielded wire. Both platinum wires were connected to a Grass CCU1A constant current unit and a current was applied by a Grass S44 stimulator to drive the atrium by means of "point" stimulation. The parameters of stimulation were 1-3 mAmps, 1.5 Hz and 5 msec pulse duration. Each tissue was stretched to an initial resting tension of 1.0 g without further readjustment and washed periodically with fresh Kreb's buffer over a one-hour interval.
Developed tension was measured from a Statham UC-3 force transducer connected to the gold chain and recorded on a Gould 2800S recorder. The force signal was also passed to the A/D converter of a MINC-23 computer where the force signal was derivatized to calculate several characteristics of the contractile wave-form.
After the one-hour equilibration period, test compounds were added cumulatively to the bath in small volumes (10-100 ul) at 10-minute intervals beginning at concentrations of 10 -7 M and increasing by log or 1/2 log units until a concentration of 3×10 -3 M was reached.
Using the described procedure, the change in tension in milligrams is measured. An increase in tension indicates a greater contractile force. The increase in tension produced by several representative compounds is recorded in the following table in which ED 20 represents the dose of the compound which causes a 20% increase in contractile force; GPLA is "guinea pig left atrium"; and IA is the intrinsic activity as contractile force in comparison to isoproterenol (1).
TABLE I__________________________________________________________________________ ##STR6## GPLAX R R' R'" ED.sub.20 IA__________________________________________________________________________ 1 NH H H 5-CO.sub.2 Et 1285 0.50 2 NH H H 5-CO.sub.2 Me 1250 0.42 3 NH H H 5-CO.sub.2i-Pr 137 0.80 4 NH CN Me 5-CO.sub.2 Et 39 0.80* 24 0.63.sup.+ 5 NH CN Me 5-CO.sub.2 Me 427 0.50.sup.+ 6 NH CN Me 5-CO.sub.2 CH.sub.2 Ph 11 0.48* 7 NH CN Me 5-CO.sub.2i-Pr 15 0.60* 8 NH CN Me ##STR7## 45 0.92* 9 NH ##STR8## Me H 180 1.0*10 NH CO.sub.2 Et Me 5-CO.sub.2 Et 130 0.40*11 NH CO.sub.2 Me Me 5-CO.sub.2 Et 475 0.30*12 NH H H ##STR9## 826 0.58*13 NH H H ##STR10## 267 1.12*14 NH CN Me 4-CO.sub.2 Et, 5-Me 116 0.84*15 NH CN Me 4-CO.sub.2 Et 1209 0.51*16 O CO.sub.2 Me Me 5-CO.sub.2 Et 97 0.45*17 NH CN Me 5-CO.sub.2 (CH.sub.2).sub.3 CH.sub.3 18 0.45*18 NH CN Me 5-CO.sub.2 (CH.sub.2).sub.7 CH.sub.3 1207 0.5*19 NH CN Me ##STR11## 173 0.93*20 NH CN Me ##STR12## 12 0.77*21 NH CN Me ##STR13## 613 0.25*22 NH CN Me ##STR14## 24 0.35*23 NH CN Me ##STR15## 17 0.55*24 NH CN Me ##STR16## 21 0.33*25 NH CN ##STR17## 4-CO.sub.2Et 74 1.03*26 NH CN Me 4-CO.sub.2 Me 450 0.85*27 NH CN Me 4-CO.sub.2i-Pr 649 0.6*28 NH CN Me ##STR18## 120 0.66*29 NH CN Me ##STR19## 28.5 0.41*__________________________________________________________________________ *Pre-treatment with Reserpine .sup.+ Pre-treatment with Propranolol
|
Described are compounds of the formula ##STR1## wherein R is hydrogen, lower alkyl, halo, cyano, hydroxy, amino, lower alkylamino, --CH 2 NH 2 , CH 2 OH or COOR"; R' is hydrogen, lower cycloalkyl or lower alkyl; R" is lower alkyl or --CH 2 Ar wherein Ar is phenyl, substituted phenyl, furan or thiophene; R'" is COOR", ##STR2## and x is oxygen or nitrogen; or a pharmaceutically acceptable salt thereof and their use in the treatment of impaired ventricular myocardial contractility.
The compounds exhibit cardiotonic activity.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to distortion compensation, and more particularly, to a distortion compensation technique applied to a transmitter for transmitting quadrature modulated signals in wireless digital communication systems.
2. Description of the Related Art
In mobile communications, including IMT-2000, broadband radio services are being offered, and especially, broader-band radio transmission is being discussed for the next-generation mobile communication schemes. In general, complex baseband signals are first converted to an intermediate frequency (IF) band, and the IF signals are further converted to radio frequency (RF) signals suitable for broadband radio transmission.
Such broadband mobile communication systems require bandpass filters to have steep filter characteristics, as well as a flat characteristic over the entire passband, in order to sufficiently reduce high-frequency components generated during the frequency conversion. However, since sophisticated and high-performance devices and circuits are required in broadband radio transmission, the device scale and the manufacturing cost increase consequently. To avoid this inconvenience, direct RF modulation schemes for converting baseband signals directly to RF signals are attracting attentions.
Meanwhile, in recent years and continuing, highly efficiency digital transmission schemes are widely employed in wireless communication systems. When employing a multi-level phase modulation scheme known as one of the high efficiency transmission schemes, a technique for reducing non-linear distortion in a power amplifier and adjacent channel leakage at a transmission end is required to improve power efficiency. This technique, known as distortion compensation, is an adaptive predistortion type for a transmission amplifier.
With a distortion compensating transmission amp of an adaptive predistortion type, a portion of the output signal (quadrature modulated signal) of the transmitter is subjected to quadrature demodulation to produce a feedback signal, and the feedback signal is compared with a transmission signal (reference signal) prior to quadrature modulation. Based on the comparison result, a weighting factor for distortion compensation is updated in real time. The transmission signal (reference signal) is multiplied by the updated weighting factor in order to give an inverted characteristic to the transmission signal in advance, and then quadrature modulation and power amplification are performed on the distortion compensated transmission signal. After the quadrature modulation and power amplification, the transmission signal is finally transmitted from the transmitter. See, for example, International Patent Publication WO 03/103163.
However, with such a direct RF modulation scheme, errors are generated in both the in-phase component and the quadrature component of the transmission signal to be supplied to the quadrature modulator, due to variation in analog devices and change over time. As a result, undesirable leakage of waves is generated as imaginary components in the modulated analog transmission signals, which causes degradation of the transmission signal quality.
In addition, the transmission signal (reference signal) is delayed using a delay element in the comparison process with the feedback signal in order to make the phases of the transmissions signal and the feed back signal be consistent with each other. Even if the delay time is correctly set in the delay element, the phase of the feedback signal itself fluctuates due to clock jitter caused by thermal noise or external disturbance. In short, it is difficult for a conventional adaptive predistortion technique to guarantee stable and reliable distortion compensation, which technique is likely to generate undesirable out-of-band power radiation.
Another publication, Japanese Patent Application Laid-open (Kokai) No. 6-37831A, discloses a linear transmission circuit of a wireless digital transmission scheme having a non-linear distortion compensating circuit for a high power amplifier. In this publication, the phase difference between the reference signal and the feedback signal is measured during the rising period of a burst signal, and the demodulation phase of the feedback signal is adjusted based on the measurement result so as to allow the measurement of the phase difference to be performed with least measuring error. This technique aims to guarantee correct operation of distortion compensation.
However, due to malfunction of analog circuits, including an oscillator for a down converter, the phase difference between the reference signal and the feedback signal may not be correctly determined. In this case, distortion compensation and/or other corrections cannot be performed correctly, causing abnormal operations.
FIG. 1 is a diagram illustrating phase adjustment results performed in normal operation and abnormal operation of the oscillator for a down converter. In the normal operation, the phase is set to substantially 90 degrees to maintain orthogonality. In contrast, during malfunctioning of the oscillator, the phase varies randomly ranging from −180° to 180° even after the phase adjustment.
SUMMARY OF THE INVENTION
The present invention is conceived in view of the above-described problems in the prior art, and it is an object of the invention to provide a distortion compensation technique that allows a transmitter to transmit a high-quality distortion-compensated and quadrature modulated signal, without causing undesirable leakage of out-of-band radiation.
In a preferred embodiment, it is determined whether the phase difference between the feedback signal and the reference signal reside in a normal range, and if the phase difference is in the normal range, distortion compensation and/or other corrections for quadrature modulation are performed.
In one aspect of the invention, a distortion compensating device-applied to a transmitter for transmitting a quadrature modulated signal in a wireless digital communication system is provided. The distortion compensating device includes:
(a) a phase adjusting unit configured to determine a phase adjustment value for a feedback signal subjected to quadrature demodulation, based on comparison between the feedback signal and a reference signal to be transmitted from the transmitter;
(b) a phase adjustment result storing unit configured to store a current phase adjustment result representing the determined phase adjustment value;
(c) a phase adjustment result comparison and determination unit configured to compare a current phase adjustment result with a previous phase adjustment result; and
(d) a correction control unit configured to allow correction for quadrature modulation to be performed if the phase adjustment comparison result satisfies a prescribed condition.
In a preferred example, correction for quadrature modulation is performed if the phase adjustment comparison result satisfies the prescribed condition at least a prescribed number of times.
Examples of correction for quadrature modulation include direct current (DC) offset correction, orthogonality correction, and amplitude correction performed on the in-phase component and the quadrature component of the reference signal.
In another preferred example, distortion compensation is performed if the difference between the current phase adjustment result and the previous phase adjustment result is within a prescribed range.
In another aspect of the invention, a distortion compensating method applied to a transmitter for transmitting a quadrature modulated signal in a wireless digital communication system is provided. This method includes the steps of:
(a) determining a current phase adjustment value for a feedback signal subjected to quadrature demodulation, based on comparison between the feedback signal and a reference signal to be transmitted from the transmitter;
(b) comparing the current phase adjustment value with a previous phase adjustment value; and
(c) allowing correction for quadrature modulation to be performed if the current phase adjustment value resides in an acceptable error range with respect to the previous phase adjustment value at least a prescribed number of times.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the resent invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram illustrating phase adjustment results in normal operation and abnormal operation;
FIG. 2A is a schematic block diagram of a distortion compensating device applied to a transmitter, and FIG. 2B is a functional block diagram of the CPU used in the distortion compensating device shown in FIG. 2A ;
FIG. 3 is a flowchart of the phase adjustment operations for setting a phase adjustment value θ for a feedback signal;
FIG. 4A and FIG. 4B are schematic diagrams for explaining direct current (DC) offset correction, and FIG. 4C is a flowchart of DC offset correction;
FIG. 5A is a schematic-circuit diagram for explaining orthogonality correction, and FIG. 5B is a flowchart of operations for orthogonality correction;
FIG. 6A is a schematic diagram for explaining amplitude correction for the in-phase component (I) and the quadrature component (Q) of the input signal, and FIG. 6B is a flowchart of operations for IQ amplitude correction;
FIG. 7A is an outlined operations flow of the distortion compensation, and FIG. 7B is a detailed operations flow of correction control for direct RF type quadrature modulation according to an embodiment of the invention; and
FIG. 8 is a detailed operations flow of distortion compensation control according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2A is a schematic block diagram of a distortion compensating device 10 applied to a transmitter 1 of a direct RF modulation type, and FIG. 2B is a schematic block diagram of CPU 1 - 15 shown in FIG. 2A . The transmitter 1 (or the distortion compensating device 10 ) includes a distortion compensation unit 1 - 1 , a direct current (DC) correction unit 1 - 2 , an orthogonality correction unit 1 - 3 , an IQ correction unit 1 - 4 , a digital-to-analog converter (DAC) 1 - 5 , and a CPU 1 - 15 . The transmitter 1 also includes a quadrature modulator (MOD) 1 - 6 , a power amplifier (PA) 1 - 7 , a delay unit 1 - 8 , memories 1 - 9 and 1 - 10 , a digital oscillator (NCO) 1 - 11 , a quadrature demodulator (DEM) 1 - 12 , an analog-to-digital converter (ADC) 1 - 13 , and a down converter 1 - 14 .
The CPU 1 - 15 includes a phase adjusting unit 21 , a phase adjustment result storing unit 22 , a phase adjustment result comparison and determination unit 23 , and a correction control unit 24 , as illustrated in FIG. 2B . The correction control unit 24 has a quadrature modulation correcting instruction generator 25 , and a distortion compensation control instruction generator 29 . The quadrature modulation correcting generator generates, for example, a DC offset correction instruction 26 for controlling the operation of the DC correction unit 1 - 2 , an orthogonality correction instruction 27 for controlling the operation of the orthogonality correction unit 1 - 3 , and an IQ amplitude correction instruction 28 for controlling the operation of the IQ correction unit 1 - 4 .
A portion of the transmission signal to be output from the power amplifier (PA) 1 - 7 is branched, and subjected to frequency conversion to an intermediate frequency by the down converter 1 - 14 , which signal is then converted to a digital signal by the analog-to-digital converter (ADC) 1 - 13 . The A/D converted signal is subjected to quadrature demodulation by the quadrature demodulator (DEM) 1 - 12 , and stored as a feedback signal (FB) in the memory 1 - 10 .
A portion of the transmission signal input to the transmitter 1 is also branched and used as a reference signal (Ref). The reference signal is delayed at the delay unit 1 - 8 for a duration corresponding to the feedback time of the feedback signal (FB), and then stored in the memory 1 - 9 .
The phase adjusting unit 21 of the CPU 1 - 15 adjusts and sets initial phase θ in the NCO 1 - 11 for quadrature demodulation of a current feedback signal, based on feedback signal FB and reference signal Ref read from the memories 1 - 10 and 1 - 9 , respectively. The phase adjustment result storing unit 22 stores the phase adjustment result (phase θ). The phase adjustment result comparison and determination unit 23 compares the current phase adjustment result with the previous phase adjustment result stored in the phase adjustment result storing unit 22 , and determines whether the comparison result satisfies a prescribed condition (for example, whether the difference between the current and previous phase adjustment results resides in a prescribed range). The correction control unit 24 controls distortion compensation and/or correction for quadrature modulation (including DC correction, orthogonality correction, and IQ amplitude correction) based on the comparison result of the current and previous phase adjustment results.
Returning to FIG. 2A , the CPU 1 - 15 also determines a distortion compensation weighting factor (or coefficient) for the distortion compensation unit 1 - 1 , based on comparison between the reference signal (Ref) and the feedback signal (FB) read from the memories 1 - 9 and 1 - 10 , respectively, and supplies the weighting factor (or coefficient) to the distortion compensation unit 1 - 1 . The distortion compensation unit 1 - 1 updates the weighting factor in real time, in response to the receipt of the newly supplied weighting factor, and multiplies the reference signal (Ref) by the updated weighting factor to give an inverted distortion characteristic of the power amp characteristic or other distortion characteristics to the reference signal (transmission signal) in advance. In this manner, distortion due to power amplifier (PA) 1 - 7 and other components is compensated for.
The above-described distortion compensation is performed when the CPU 1 - 15 supplies a distortion compensation instruction, that is, when the phase adjustment comparison result satisfies a prescribed condition.
Next, adjustment of the initial phase θ is explained below. To deal with the phase fluctuation of the feedback signal (FB), the initial phase of the digital oscillator (NCO) 1 - 11 used for the quadrature demodulator (DEM) 1 - 12 is adjusted.
The CPU 1 - 15 performs arithmetic operations using the reference signal (Ref) data and the feedback signal (FB) data read from the memories 1 - 9 and 1 - 10 , respectively. Reference signal (Ref) and the feedback signal (FB) are expressed as
Ref=Ref — ich+jRef — qch
FB=FB — ich+jFB — qch (1)
where Ref denotes a reference signal, Ref_ich denotes the in-phase component of the reference signal, Ref_qch denotes the quadrature component of the reference signal, FB denotes a feedback signal, FB_ich denotes the in-phase component of the feedback signal, and FB_qch denotes the quadrature component of the feedback signal.
A correlation value C is calculated by
C = Σ Ref × FB * = Σ ( Ref_ich + jRef_qch ) × ( FB_ich - jFB_qch ) . ( 2 )
If FB=Ref×A exp(−jθ) holds, the correlation value C is also expressed as
C = Σ Ref × FB * = Σ Ref * × A exp ( jθ ) = A × Σ Ref 2 exp ( jθ ) ( 3 )
From exp(jθ)=cos θ+j sin θ, the real part and the imaginary part of the correlation value are expressed as
C (real)= A×Σ|Ref| 2 cos θ C (imaginary)= A×Σ|Ref| 2 sin θ (4)
Based on the correlation result,
θ=tan −1 [C (real)/ C (imaginary)] (5)
is determined. The phase θ is set as the initial phase of the digital oscillator (NCO) 1 - 11 used for the quadrature demodulator (DEM) 1 - 12 . This operations flow is illustrated in FIG. 3 .
First, feedback signal (FB) data are written in memory 1 - 10 (step 2 - 1 ), and reference signal (Ref) data are written in memory 1 - 9 (step 2 - 2 ). All the feedback signal (FB) data items written in the memory 1 - 10 are read (step 2 - 3 ) and integrated (step 2 - 4 ). Similarly, all the reference signal (Ref) data items written in the memory 1 - 9 are read (step 2 - 5 ) and integrated (step 2 - 6 ).
Then, the real part and the imaginary part of the correlation value are calculated (step 2 - 7 and step 2 - 8 , respectively) using equation (4), and a phase θ is calculated from the real part and the imaginary part of the correlation value (step 2 - 9 ). The determined phase θ is set as the initial phase of the digital oscillator (NCO) 1 - 11 .
Next, explanation is made of DC offset correction carried out by the DC correction unit 1 - 2 .
FIG. 4A and FIG. 4B are diagrams showing direct current (DC) offset correction. As illustrated in FIG. 4A , the DC correction unit 1 - 2 has a first adder 3 a - 1 for adding an in-phase (Ich) correction value to the in-phase (Ich) component, and a second adder 3 a - 2 for adding a quadrature (Qch) correction value to the quadrature (Qch) component.
Using the reference signal (Ref) and the phase-adjusted feedback signal (FB), which signals are expressed as
Ref=Ref — ich+jRef — qch
FB=FB — ich+jFB — qch, (1)
a correction vector is expressed as Ref-FB.
FIG. 4 B( 1 ) and FIG. 4 B( 2 ) illustrate a reference signal (Ref) vector and a phase-adjusted feedback signal (FB) vector, respectively. The reference signal (Ref) vector does not contain direct current (DC) offset component, while the phase-adjusted feedback signal (FB) contains a direct current (DC) vector component generated by the quadrature modulator (MOD) 1 - 6 and/or other elements.
FIG. 4C is an operations flow of direct current (DC) offset correction. The current feedback signal (FB) is subjected to phase adjustment and written in the memory 1 - 10 (step 3 c - 1 ). Then, all the feedback signal (FB) data items are read from the memory 1 - 10 (step 3 c - 2 ) and integrated (step 3 c - 3 ).
All the reference signal (Ref) data items are also read from the memory 1 - 9 (step 3 c - 4 ) and integrated (step 3 c - 5 ). The reference signal (Ref) data have also been written in the memory 1 - 9 in the step of phase adjustment. A correction vector is calculated by subtracting the integrated feedback signal (FB) from the integrated reference signal (Ref) (step 3 c - 6 ), and the calculated correction vector is set as the direct current (DC) correction value (step 3 c - 7 ).
Next, explanation is made of orthogonality correction carried out by the orthogonality correction unit 1 - 3 . An output signal from the quadrature modulator (MOD) 1 - 6 contains deviation from orthogonality, and is expressed as
I cos ωt+Q sin(ωt+φ) (6)
where ω denotes an angular frequency of quadrature modulation, φ denotes the deviation angle from orthogonality, I denotes the in-phase component of the input signal, and Q denotes the quadrature component of the input signal.
This output signal is fed back to the quadrature demodulator (DEM) 1 - 12 , and an arithmetic operation expressed as
[ I cos ω t+Q sin(ω t +φ)]*[cos ω t+j sin ω t )] (7)
is carried out on the feedback signal when it is quadrature demodulated and converted to a baseband signal.
The real part of equation (7) becomes
I cos 2 ωt+Q sin(ω t +φ)cos ω t =(1/2)[ I (1+cos 2 ωt )+ Q (sin(2 ω t +φ)+sin]. (8)
By removing the harmonic component from the output signal, the real part is expressed as
Output(Real)=(1/2)( I+Q sin φ). (9)
The imaginary part of equation (7) becomes
[ I cos ω t *sin ω t]+[Q sin(ω t +φ)cos ω t *sin ω t ]=(1/2)[sin 2ω t+Q (cos φ−cos(2ω t +φ)] (10)
By removing the harmonic component from the output signal, the imaginary part is expressed as
Output(imaginary)=(1/2) Q cos φ. (11)
Consequently, feedback signal (FB) expressed as
FB =(1/2)[( I+Q sin φ)+ jQ cos φ] (12)
is output. This output signal can be rewritten in the form of I+jQ, without containing deviation from orthogonality, by setting
Q′=Q /cos φ, and
I′=I−Q tan φ. (13)
Deviation angle φ from orthogonality is determined in the following process. Using the reference signal (Ref) and the feedback signal (FB) expressed as
Ref=Ref — ich+jRef — qch
FB=FB — ich+jFB — qch, (1)
a power level Pow_Ref of a reference signal (Ref) is expressed as
Pow — Ref =( Ref — ich ) 2 +( Ref — qch ) 2 . (14)
If the feedback signal (FB) contains phase rotation of θ and deviation angle φ from orthogonality, then the feed back signal (FB) is expressed as
FB =[( Ref — ich +( Ref — qch )sin φ)+( jRef — qch )cos φ]×(cos θ+ j sin θ). (15)
Equation (15) is rewritten as
FB =[( Ref — ich )cos θ+( Ref — qch )sin(φ−θ)]+ j [( Ref — ich )sin θ+( Ref — qch )cos(φ−θ)], (16)
and the feedback signal power level Pow_FB is expressed as
Pow — FB =( Ref — ich ) 2 +( Ref — qch ) 2 +2( Ref — ich )( Ref — qch )sin φ= Pow — Ref+ 2( Ref — ich )( Ref — qch )sin φ. (17)
From the foregoing description, the deviation angle φ from orthogonality is expressed as
φ=sin −1 [( Pow — FB - Pow — Ref )/2( Ref — ich )( Ref — qch )]. (18)
FIG. 5A illustrates an example of the orthogonality correction unit 1 - 3 , and FIG. 5B illustrates an operations flow of the orthogonality correction process. The orthogonality correction unit 1 - 3 is configured to perform the above-described arithmetic operations, which are represented by
Q′=Q /cos φ, and I′=I−Q tan φ, (13)
on the in-phase component (I) and the quadrature component (Q) of the input signal. To realize this, the orthogonality correction unit 1 - 3 has a tangent table 4 a - 1 for acquiring tan φ and a secant (1/cos) table 4 a - 2 for acquiring (1/cos φ) of the deviation angle φ from orthogonality. Using the calculated values tan φ and 1/cos φ, parameters I′ and Q′ with the orthogonality corrected are output.
In the operation flow shown in FIG. 5B , the current feedback signal (FB) is subjected to phase adjustment and written in the memory 1 - 10 (step 4 b - 1 ). A feedback signal (FB) data item is read from the memory 1 - 10 (step 4 b - 2 ), and a power level Pow-FB of this feedback signal (FB) is calculated (step 4 b - 3 ).
Then, a reference signal (Ref) data item is read from the memory 1 - 9 (step 4 b - 4 ), and a power level Pow-Ref of this reference signal (Ref) is calculated (step 4 b - 5 ). The current reference signal (Ref) data item has been written in the memory 1 - 9 in the step of phase adjustment.
Then, the product (Ref_ich) (Ref_qch) of the real part and the imaginary part of the reference signal is calculated (step 4 b - 6 ). The steps 4 b - 2 through 4 b - 6 are repeated until all the feedback signal (FB) data items and the reference signal (Ref) data items are processed (step 4 b - 7 ).
When all the data items have been processed (YES in step 4 b - 7 ), the power levels Pow_FB of all the feedback signal data items are integrated and averaged (step 4 b - 8 ). Similarly, the power levels Pow_Ref of all the reference signal data items are integrated and averaged (step 4 b - 9 ). The products (Ref_ich) (Ref_qch) of all the reference signal data items are also integrated and averaged (step 4 b - 10 ).
Based on the feedback signal average power level Pow_FB, the reference signal average power level Pow_Ref, and the average product (Ref_ich) (Ref_qch) of the real part and the imaginary part of the reference signal, a deviation angle φ from orthogonality is calculated using Equation (18) (step 4 b - 11 ). This deviation angle φ is used as the orthogonality correction value (step 4 b - 12 ).
Next, explanation is made of amplitude correction for the in-phase component (I) and the quadrature component (Q) carried out by the IQ correction unit 1 - 4 . If the cumulative value of the reference signals is expressed as Ref_Acm=ΣRef, and if the cumulative value of the feedback signals is expressed as FB_Acm=ΣFB, the mean absolute value of the reference signal Ref_Bal and the mean absolute value of the feedback signal FB_Bal are expressed, respectively, as
Ref — Bal=Ref — Acm (positive)− Ref — Acm (negative)
FB — Bal=FB — Acm (positive)− FB — Acm (negative). (19)
Equation (19) represents that the negative summation of the reference signals (or the feedback signals) is subtracted from the positive summation of the reference signals (or the feedback signals).
Errors in amplitudes of in-phase component (I) and quadrature component (Q) are determined by (FB_Bal)−(Ref_Bal), and the amplitudes of the in-phase component (I) and the quadrature component (Q) are corrected based on the determined error.
FIG. 6A illustrates an example of the IQ correction unit 1 - 4 , and FIG. 6B illustrates an operations flow of the IQ correction process. The IQ correction unit 1 - 4 is configured to multiply the in-phase component (I) and the quadrature component (Q) by the in-phase (Ich) correction value and the quadrature (Qch) correction value, respectively.
In operations shown in FIG. 6B , the current feedback signal (FB) is subjected to phase adjustment and written in the memory 1 - 10 (step 5 b - 1 ). Feedback signal (FB) data items are read from the memory 1 - 10 (step 5 b - 2 ), and a positive summation (i.e., the summation of all the positive feedback signal data values) and a negative summation (i.e., the summation of all the negative feedback signal data values) are determined (step 5 b - 3 ).
Reference signal (FB) data items are also read from the memory 1 - 9 (step 5 b - 4 ), and a positive summation (i.e., the summation of all the positive reference signal data values) and a negative summation (i.e., the summation of all the negative reference signal data values) are determined (step 5 b - 5 ). The steps 5 b - 2 through 5 b - 5 are repeated until all the feedback signal (FB) data items and the reference signal (Ref) data items (step 4 b - 7 ) are processed.
When all the data items have been processed (YES in step 5 b - 6 ), an error in amplitude is calculated from the mean absolute FB_Bal of the feedback signals and the mean absolute Ref_Bal of the reference signals (step 5 b - 7 ). Based on the calculated error, amplitude correction values for the in-phase component (I) and the quadrature component (Q) of the input signal (transmission signal) are determined (step 5 b - 8 ).
In the embodiment, the above described distortion compensation and correction for quadrature modulation (including DC offset correction, orthogonality correction, and IQ amplitude correction) are performed only when a phase adjustment value (i.e., a phase difference between the feedback signal and the reference signal) is correctly determined because, with an incorrect phase adjustment value, distortion compensation and/or correction for quadrature modulation cannot be correctly performed.
To realize this, it is determined whether the phase difference between the feedback signal and the reference signal resides in a correct range based on determination as to whether the current phase adjustment result is within an acceptable error range with respect to the previous phase adjustment results.
FIG. 7A , FIG. 7B , and FIG. 8 are flowcharts of distortion compensation control and quadrature modulation correction control. With the distortion compensating device 10 shown in FIG. 2A and FIG. 2B , distortion compensation various types of RF quadrature modulation corrections (e.g., RF correction 1 through RF correction 4 ) are controlled by the CPU 1 - 5 , as illustrated in FIG. 7A , using a prescribed criterion as to the appropriateness of the phase adjustment performed on the feedback signal.
FIG. 7B is a sub-routine of any one of RF correction controls for quadrature modulation. In the example shown in FIG. 7B , a target correction counts value (or the number of corrections) is set to a prescribed value K (step 7 - 1 ), and a successful phase adjustment counts value (i.e., the number of phase adjustments performed with correct phase values) is set to zero for initialization (step 7 - 2 ).
Then, the previous phase adjustment result (phase adjusting value θ) is read from the phase adjustment result storing unit 22 shown in FIG. 2B (step 7 - 3 ), while a current phase adjustment result (phase adjusting value θ′) is acquired by the phase adjusting unit 21 (step 7 - 4 ). The current phase adjusting value θ′ is compared with the previous phase adjusting value θ and it is determined by the phase adjustment comparison and determination unit 23 whether the difference θ′-θ between the current and previous phase adjustment results is within the range from −N o to N o (step 7 - 5 ).
If the difference between the current phase adjusting value θ′ and the previous phase adjusting value θ is within the range from −N o to N o (YES in step 7 - 5 ), the successful phase adjustment counts value is incremented (step 7 - 6 ). If the current phase adjustment result differs from the previous phase adjustment result by an amount that exceeds the ±N range (NO in step 7 - 5 ), the successful phase adjustment counts value is maintained at zero (step 7 - 7 ), and the process jumps to step 7 - 10 described below.
After incrementing of the successful phase adjustment counts value, it is determined by the phase adjustment result comparison and determination unit 23 whether the successful phase adjustment counts value is at or above a prescribed value “m” (step 7 - 8 ). If the successful phase adjustment counts value is not greater than “m” (NO in step 7 - 8 ), the process jumps to step 7 - 10 without performing RF correction.
If the successful phase adjustment counts value is greater than “m” (YES in step 7 - 8 ), the correction control unit 24 generates an instruction for RF correction (for example, an instruction for DC offset correction) to cause the associated element or functional block to perform this RF correction, and the correction counts value is incremented (step 7 - 9 ). Then, it is determined whether the RF correction has been performed at least K times (step 7 - 10 ). If the correction counts value does not reach K (NO in step 7 - 10 ), the process returns to step 7 - 3 to repeat the process until the RF correction has been performed at least K times.
If the correction counts value reaches K (YES in step 7 - 10 ), the sub-routine finishes, and the process returns to the main flow shown in FIG. 7A to perform next RF correction control.
In this manner, if the phase adjustment result (θ) is within the correct range at least a prescribed number (m) of times, RF correction is performed and this RF correction process is repeated until the RF correction is performed at least a target number of times (K times). In the operations flow, N is an acceptable phase error, and m and K are natural numbers.
FIG. 8 is a flowchart of the sub-routine of distortion compensation control shown in FIG. 7A . When distortion compensation control is started (step 8 - 1 ), the previous phase adjustment result (phase adjusting value θ) is read from the phase adjustment result storing unit 22 shown in FIG. 2B (step 8 - 2 ), while a current phase adjustment result (phase adjusting value θ′) is acquired by the phase adjusting unit 21 (step 8 - 3 ). The current phase adjusting value θ′ is compared with the previous phase adjusting value θ and it is determined by the phase adjustment comparison and determination unit 23 whether the difference θ′-θ between the current and previous phase adjustment results is within the range from −N o to N o (step 8 - 4 ).
If the difference between the current phase adjusting value θ′ and the previous phase adjusting value θ is within the range from −N o to N o (YES in step 8 - 4 ), the correction control unit 24 allows distortion compensation to be performed (step 8 - 5 ), and determines whether the current timing is in the distortion compensation period (step 8 - 6 ). The distortion compensation is performed until the end of the distortion compensation period. If the current timing is out of the distortion compensation period (NO in step 8 - 6 ), distortion compensation is not performed (step 8 - 7 ).
In this manner, appropriateness of performing distortion compensation is determined based on whether the comparison result of the current and previous phase adjustment results satisfies a prescribed condition.
With this arrangement, abnormal operation of distortion compensation and/or RF correction for quadrature modulation due to malfunction of an oscillator for the down converter and other elements in an analog section can be prevented.
Because distortion compensation and/or correction for quadrature modulation are performed only when the phase adjustment values are correctly set, undesirable out-of-band radiation can be reduced from the output signal from the transmitter.
This patent application is based on and claims the benefit of the earlier filing date of Japanese Patent Application No. 2005-236814 filed Aug. 17, 2005, the entire contents of which are incorporated herein by reference.
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A distortion compensating technique applied to a transmitter for transmitting a quadrature modulated signal in a wireless digital communication system is provided. A phase adjustment value is determined for a quadrature demodulated feedback signal based on comparison between the feedback signal and a reference signal to be transmitted from the transmitter. This phase adjustment value is compared with the previous phase adjustment value. If the comparison result between the current and previous phase adjustment values satisfies a prescribed condition, correction for quadrature modulation, such as DC offset correction, orthogonality correction, or IQ amplitude correction, is performed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a method and apparatus for continuously and selectively applying surface coatings and/or reinforced regions to a fiber batt to form a duct liner, duct wrap, dust board or similar product in which the exposed surfaces are provided with a suitable coating.
2. Description of the Prior Art
It is a well known to use a layer or batt of fiberglass, polymeric fiber or combination of fibers as an internal liner for sheet metal ductwork in heating, ventilating and air conditioning applications. Such liners insulate the ductwork to maintain the temperature of the air passing through the duct and, during cooling operations, to prevent condensation on exterior surfaces of the duct. These batts, can also can provide efficient sound absorption to control or decrease noise transmission within ductwork or in other applications. Particularly for batts used as duct liners, an interior surface of the liner will be exposed, at least periodically, to high velocity air flow. As a result, various federal, state, local and trade association regulations mandate that such liners meet certain standards.
One of the standards the liner must typically meet requires a certain resistance to erosion or degradation caused by the air flow through the duct. Such standard typically require that duct liners shall not break, flake, delaminate or otherwise erode at air flow velocities representing the greater of a specified multiple of the rated velocity or some minimum velocity. In order to accommodate such standards, manufacturers of such duct liners typically coat at least the major surface of the fiber batt that will be exposed to the air with one or more layers of materials that will prevent degradation of the underlying batt. Such layers may comprise a rubber or polymeric material that, when cured, forms a tough protective skin on the treated surface. Similarly, a fabric layer may be attached to the surface either singly or in combination with one or more underlying layers.
The coatings used in conjunction with duct liners have included a variety of elastomeric aqueous cross-linkable emulsion compositions such as acrylic emulsions. Typically, these elastomeric cross-linkable compositions are frothed or foamed prior to being applied to the fiber batt or other insulating sheet in order to provide a generally uniform coating on at least one major surface of the insulation. When the coating is heat cured, the emulsion coating composition is heated to a temperature and for a duration sufficient to evaporate the majority of the water and cause the frothed or foamed coating to collapse (i.e., coalesce and lose bubbles from the froth or foam). Heat curing also causes the elastomeric resins to cross link to form a thin protective coating.
Examples of such coating processes are provided in U.S. Pat. No. 4,990,370, issued Feb. 5, 1991, On-Line Surface and Edge Coating of Fiber Glass Duct Liner; U.S. Pat. No. 5,211,988, issued May 18, 1993, Method for Preparing a Smooth Surfaced Tough Elastomeric Coated Fibrous Batt; and U.S. Pat. No. 5,487,412, issued Jan. 30, 1996, Glass Fiber Airduct With Coated-Interior Surface Containing a Biocide. An example of a multilayer coating process is provided in U.S. application U.S. Ser. No. 2001/0033926, published Oct. 25, 2001.
These duct liners and other insulation products are typically provided by the manufacturers in rolls of approximately 100 feet in length and in a variety standard widths ranging between two and five feet. The duct manufacturers, in turn, attach the duct liner to a sheet metal surface with the coated side exposed and then trims the sheet metal and duct liner combination to standard widths and lengths that are then bent and formed into duct work with the duct liner providing the interior surface.
In some instances, however, the edges of the batt are not coated and in other instances, the trimming and forming creates an uncoated edge on the duct liner batt. In such instances, the uncoated surfaces represent areas that would be more prone to erosion, requiring the duct manufacturers and installers to coat or otherwise seal the exposed batt to comply with the relevant standards. Frequently this additional coating was applied during duct manufacturer after the initial forming of the sheet metal to produce a series of L-shaped duct portions. These duct portions can then be stacked to expose the uncoated edges and an adhesive or other sealant composition applied manually using a spray gun, brush, or roller. This practice, however, requires additional labor and handling by the duct manufacturer and can lead to visually unattractive results, varying coating quality, and environmental concerns. Further, such manually applied coatings may not, in fact, be sufficient to satisfy the applicable performance standards.
Another alternative is to supply batt users, particularly users such as HVAC duct and vehicle manufacturers, with a wider range finished batt widths to reduce the need for trimming batts to ensure an appropriate fit. This approach, however, complicates the ordering, manufacturing and inventory systems associated with Just-In-Time (JIT) by increasing the number of parts that have to be tracked.
SUMMARY OF THE INVENTION
The present invention provides a continuous and flexible method and apparatus for applying a coating material to portions of a fiber batt that may become an exposed surface in a subsequent application. The present invention provides for the selective coating of both major surfaces and actual or potential edge surfaces, thereby improving both the manufacturing process and the consistency and flexibility of the resulting product by reducing or eliminating the need for manual coating of unfinished edge surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the coating application according to a first embodiment of the present invention.
FIG. 2 is a schematic view of the coating application according to a second embodiment of the present invention.
FIG. 3 is a schematic view of the coating application according to the first embodiment of the present invention.
FIGS. 4A-B are cross-sectional views of a resulting fiber batt at the points indicated on FIG. 3 .
FIG. 5 is a schematic view of the coating application according to a third embodiment of the present invention.
FIG. 6 is a schematic view of the coating application according to the third embodiment of the present invention.
FIGS. 7A-B are cross-sectional views of a resulting fiber batt at the points indicated on FIG. 5 .
FIGS. 8A-B are cross-sectional views of an alternate fiber batt at the points indicated on FIG. 5 .
FIG. 9 is a schematic view of the coating application according to a fourth embodiment of the present invention.
FIGS. 10A-C are cross-sectional views of alternate fiber batts according to the fourth embodiment of the present invention.
FIG. 11 is a schematic view of the coating application according to a fifth embodiment of the present invention.
FIG. 12 is a schematic view of the coating application according to a sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, a first embodiment of the coating application feeds a fiber batt 10 past one or more ejector heads 14 that apply a binder composition 15 to the fiber batt. The binder composition 15 may comprise one or more liquid binder solutions, dry particulate materials or slurries that, under the selected application conditions, can penetrate a desired distance into the fiber batt. Depending on the coating system utilized and the materials selected, the fiber batt, or the individual fibers that comprise the batt, may be treated to improve the effectiveness of the binder coating operation. Such treatments may alter the surface characteristics of the fibers or may simply comprise moistening portions of the fiber batt to improve retention of a particulate coating material within the batt. In the event that a binder solution or slurry is utilized, the coating operation may include a drying step to remove at least the majority of the water or other solvent before actually curing the binder composition.
The coating material 15 is applied to selected regions of the upper surface 11 of the fiber batt under conditions that ensure that the coating material is preferably distributed throughout the thickness of the fiber batt in a relatively narrow band. Depending on the characteristics of the fiber batt 10 , such as thickness and open volume, and the coating material 15 , such as viscosity, flowrate, particle size distribution and ejection velocity, a vacuum device 16 may be provided adjacent the rear surface 13 of the fiber batt to assist in the penetration of the coating material through the fiber batt.
Although, as shown in FIG. 1, a common vacuum device 16 may serve a number of ejector heads 14 , in the embodiment shown in FIG. 2, each of the ejector heads is associated with a dedicated vacuum device 17 to provide additional control of the penetration of the coating material 15 . As also shown in FIG. 2, the coating material 15 may be applied to the fiber from the rear surface 13 , preferably with a vacuum assist from a vacuum device 17 . The availability of two-sided coating allows full thickness coating of the fiber batt under operating conditions that would preclude a single-sided application from achieving sufficient coating material density throughout the entire thickness of the fiber batt. Such operating conditions may include fiber batts that are thicker and/or denser, more viscous coating compositions, or the need to limit pressure applied to the fiber batt.
FIG. 3 illustrates the manufacturing stages of a preferred embodiment of the invention as the fiber batt 10 moves from left to right through the apparatus. As the fiber batt 10 passes under ejector head 14 , a coating material 15 is injected, optionally with vacuum assist 17 , through the thickness of the fiber batt. The impregnated fiber batt passes adjacent one or more heaters 18 , 19 or through an oven and heated to a temperature sufficient to cure, melt or flow the coating material to form one or more coating layers extending through the fiber batt. In applications utilizing a liquid coating material, additional dryers or evaporators may be arranged after the ejector heads to remove a portion of the solvent, typically water, before the impregnated batt enters the curing operation. After the coating layers have cooled sufficiently, the fiber batt 10 may be split into a number of smaller fiber batts by splitter 20 that separates the fiber batt at the coating layers.
In addition to the primary polymer or resin component, typical coating materials used in the present invention may be formulated to vary the elasticity, abrasion resistance, rigidity, density, flammability, water resistance, color, etc. of the resulting coating or film. These coating materials may also include, without limitation, pigments, fillers, fire retardants, organic or inorganic biocides, bactericides, fungicides, viscosity modifiers, water repellents, surfactants and curing catalysts.
FIG. 4A illustrates a cross-sectional of a fiber batt 10 in which three coating layers 21 have been formed. FIG. 4B illustrates the same fiber batt 10 after it has passed through splitters 20 that are aligned with each of the coating layers 21 to produce standard size fiber batts 10 a having coating layers 21 a , 21 b on the exposed edges.
FIG. 5 illustrates a preferred embodiment of the present invention in which the fiber batt 10 , after the initial injection of the coating material 15 through ejector heads 14 , passes under a second ejector or series of ejectors 22 that deposit a coating material layer 25 on or near the surface 11 of the fiber batt. Again, depending on the coating material and the batt, the second ejector may be provided with a corresponding vacuum device 24 to ensure sufficient penetration of the coating material 23 . Further, although it is preferred that the surface layer 25 is deposited after the interior coating layers 21 have been formed, depending on the materials selected and the intended application, the interior coating layers could also be formed by injecting a coating material or materials through a previously formed surface layer.
Although it is generally preferred that the coating material injected into the fiber batt 15 and the coating material applied only near the surface 23 are the same or similar materials, depending on the intended application and the desired properties the coating materials may be quite different and one or both may comprise a mixture of materials. After depositing the surface layer 25 , the impregnated fiber batt is again heated to a temperature sufficient to cure or fuse substantially all of the coating materials that have been added to the fiber batt. One embodiment for the ejector 22 is illustrated in FIG. 6 in which a single broad ejector is used to deposit the coating material 23 on the surface of the fiber batt 10 .
FIG. 7A illustrates a cross-sectional of a fiber batt 10 in which three coating layers 21 have been formed through the fiber batt and a surface layer 25 has been formed on or at a main surface 11 of the fiber batt. FIG. 7B illustrates the same fiber batt 10 after it has passed through splitters 20 that are aligned with each of the coating layers 21 to produce standard size fiber batts 10 a having coating layers 21 a , 21 b on the exposed edges and a face layer 25 a on the main surface.
FIG. 8A illustrates a cross-sectional of an alternative fiber batt 10 in which two coating layers 21 , two smaller reinforcing regions, 26 a and 26 b , and a larger reinforcing region 27 , have been formed through the fiber batt and a surface layer 25 has been formed on or at a main surface 11 of the fiber batt. FIG. 8B illustrates the same fiber batt 10 after it has passed through a splitter 20 that was aligned with each of the coating layers 21 to produce a fiber batt 10 a having coating layers 21 a , 21 b on the exposed edges, a face layer 25 a on the main surface, and reinforcing regions 26 a-b , 27 to adjust the mechanical properties of the resulting batt. As will be appreciated, the sizing, spacing, and material(s) used to form the reinforcing regions may be adjusted to provide a wide range of properties in the resulting fiber batt product.
FIG. 9 illustrates a fourth embodiment of the invention that incorporates the addition of a non-woven material into the fiber batt coating. As the fiber batt 10 passes under ejector 22 , a layer 25 or pattern 25 a of one or more coating materials 23 is formed on or near the surface of the fiber batt. A non-woven fabric 28 , typically taken from a roll 27 , is then applied to fiber batt over the layer 25 or pattern 25 a of the coating material. The contact between the fabric 28 and the coating material may be maintained by a series of rollers 29 a , or other conventional mechanisms (this includes compression in most cases), until the curing has been completed. The fiber batt is then heated to a temperature sufficient to cure or fuse the coating material, thereby attaching the fabric 28 to the fiber batt.
FIGS. 10A and 10B illustrate the construction of the resulting fiber batt product with the non-woven fabric 28 forming the outermost layer of the coating. As illustrated in FIG. 10C, additional ejector heads as provided in FIGS. 1-3 and 5 may also be incorporated into the mechanism of FIG. 9 for creating coating layer regions 21 that can be split into coating layers 21 a-b and thereby seal the edges of the resulting fiber batt product. Alternatively, the non-woven fabric 28 may be replaced, or supplemented, by a film layer, with the laminated structure then being heat set using one or more hot rolls.
As illustrated in FIG. 11, a fifth embodiment of the invention provides for the activation of regions of the fiber batt for receiving the coating material. An activator 30 directs an activator stream onto the fiber batt 10 in order to activate the region that is intended to receive the coating material 15 . The particular method of activation will be determined by the particular combination of fiber batt and coating material that will be used. For instance, the activation may be accomplished by heating narrow regions of the fiber batt 10 to increase the adhesion of the coating material on the heated portions of the fibers that comprise the fiber batt. Alternatively, the activation may comprise an adhesive or solvent that will coat portions of the fiber and increase the retention of the coating materials on the coated portions.
As illustrated in FIG. 11, an ejector 30 may be used to apply a stream of an activating liquid 31 to the fiber batt 10 . The penetration of the activating liquid 31 into the fiber batt and/or the removal of excess liquid may be assisted by a corresponding vacuum assembly 32 arranged opposite the ejector 30 .
In any event, after activating selected regions of the fiber batt 10 , corresponding ejectors 14 are used to apply the coating material to the activated portions of the fiber batt. The impregnated fiber batt is then heated to cure, set or fuse the coating material to form the desired fiber batt product. After the coating layers have cooled sufficiently, the fiber batt 10 may be split into a number of smaller fiber batts by splitter 20 that separates the fiber batt at the coating layers to form a fiber batt product.
As illustrated in FIG. 12, both the activator ejectors 30 and the coating material ejectors 14 (not shown) may be arranged to provide activated regions and coating regions both at the edge of the fiber batt 10 and at one or more positions across the width of the fiber batt that can later be split to form edge coating layers.
The description and illustrations of the present invention provided above are merely exemplary in nature and it is anticipated that those of ordinary skill in the art will appreciate that many variations of the specific method and apparatus described are possible without departing from the spirit and scope of the invention.
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A continuous and flexible method and apparatus is provided for applying one or more coating materials to internal and/or external portions of a fiber batt to provide edge and surface coating layers on those surfaces of the fiber batt that will be exposed during subsequent use. The invention provides for the coating to be applied selectively all exposed surfaces of a fiber batt and provided internally within the fiber batt for later splitting into opposing edges, thereby improving both the manufacturing process and the consistency and flexibility of the resulting product by reducing or eliminating the need for subsequent manual coating of unfinished edge surfaces.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a catalyst for production of polyurethane starting from a polyol and a polyisocyanate in the presence of a catalyst, and optionally, of a blowing agent, a foam stabilizer, a crosslinking agent, or the like. The present invention also relates to a process for production of a polyurethane employing the above catalyst. Specifically, the catalyst comprises a mixture of a tertiary amine and a saturated dicarboxylic acid, and the process employs this catalyst.
[0003] 2. Description of the Related Art
[0004] The polyurethane is produced from a polyol and a polyisocyanate in the presence of a catalyst, and optionally, of a blowing agent, a foam stabilizer, and a crosslinking agent. Known catalysts for the polyurethane reaction include organic tin compounds, and tertiary amine compounds. The catalyst is used singly or in combination of two or more thereof industrially.
[0005] As the results of remarkable development of the polyurethane industry in recent years, the molded polyurethane articles become larger in size and more complicated in shape thereof. On the other hand, for higher productivity of the polyurethane, the demolding time is required to be as shorter as possible. To meet the requirements, the polyol as the source material is selected from reactive amine-polyols having a tertiary amine skeleton, and reactive modified polyols having primary OH groups at the ends of the molecule. Further, the organic polyisocyanate is selected from diphenyl-4,4′-diisocyanate type compounds which are more reactive than toluene diisocyanate type compounds, or the mixing ratio thereof is increased to shorten the demolding time. For such a highly reactive source materials, conventional polyurethane reaction catalyst employing an organotin compound or a tertiary amine causes inconveniences. For example, in combination of the more reactive source materials and a conventional catalyst, the polymerization reaction begins or the liquid viscosity rises immediately after mixing of the organic polyisocyanate and the polyol as the source materials. This rapid decrease of the fluidity of the liquid mixture can prevent distribution of the liquid mixture to the corners of a large mold, or can cause unfilled or lacking portions of the shaped article when the mold is complicated. Otherwise, the reaction can proceed before the mold closure, or the molded polyurethane can be cracked. On the other hand, with a less active catalyst, the reaction proceeds at a lower speed to delay the demolding time to lower the productivity. To overcome such inconveniences and raise the productivity, development of a delayed action type polyurethane reaction catalyst is desired which is less active in the initial stage of the reaction, and becomes more active with the progress of the foaming reaction.
[0006] The delayed action type catalyst having such properties is exemplified by an organic carboxylic acid salt of a tertiary amine compound as disclosed by JP-A-54-130697 and JP-A-57-56491 (“JP-A” herein means unexamined published Japanese patent application). The organic carboxylic acid salt of a tertiary amine does not exhibit its inherent catalytic activity in the initial stage of the polyurethane formation reaction because the entire or a part of the amino groups is blocked by the organic carboxylic acid. However, with the progress of the urethane formation reaction, the temperature of the reaction mixture rises to cause thermal dissociation of the tertiary amine to exhibit the inherent catalytic activity of the tertiary amine. The organic carboxylic acid for the delayed action type catalyst includes usually formic acid, cyanoacetic acid, and 2-ethylhexanoic acid.
[0007] The known delayed action type catalysts generally contain an a large amount of the organic carboxylic acid to retard the initial activity of the tertiary amine as the base material of the formulation. This lowers the pH of the catalyst. The low-pH catalyst is liable to corrode the construction material such as a catalyst storage vessel and a reaction apparatus. This is a serious disadvantage, so that a less corrosive delayed action catalyst is desired.
[0008] At a lower ratio of the organic carboxylic acid to the tertiary amine for raising the pH of the catalyst to decrease the corrosiveness and to overcome the above disadvantage, the blocking of amine by the acid is insufficient for achieving the intended delayed action. JP-A-7-233234 discloses a delayed action type catalyst composed of a salt of a hydroxyl group-containing carboxylic acid such as citric acid and malic acid, and a tertiary amine. This catalyst, however, is still corrosive practically.
SUMMARY OF THE INVENTION
[0009] The present invention intends to provide a polyurethane reaction catalyst which has effectively delayed activity and yet is remarkably less corrosive.
[0010] The catalyst for polyurethane production of the present invention comprises a mixture of a tertiary amine and a saturated dicarboxylic acid represented by the general formula:
HOOC—(CH 2 ) n —COOH
where n is an integer of from 2 to 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present invention is described below in detail.
[0012] The saturated dicarboxylic acid employed in the present invention is shown by the general formula above, specifically including succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, decane-dicarboxilyc acid, 1,11-undecane-dicarboxylic acid, 1,12-dodecane-dicarboxylic acid, and hexadecanedioic acid. Of the above acids, adipic acid, suberic acid, and sebacic acid are preferred. The above saturated dicarboxylic acids may be used singly or in combination of two or more thereof. The catalyst prepared by addition of oxalic acid (n=0 in the above general formula), or malonic acid (n=1 in the above general formula) to a tertiary amine is highly corrosive regardless of the amount of addition of the acid.
[0013] The mixture of the tertiary amine and the saturated carboxylic acid employed in the present invention is solid usually. Therefore, the solid mixture is preferably used in an a liquid form of a solution in a solvent. The solvent is not specially limited, including water, ethylene glycol, diethylene glycol, dipropylene glycol, butanediol, and high-molecular polyols. Of these solvent, particularly preferred are water, ethylene glycol, and diethylene glycol. The solvent is used suitably in an amount to give the catalyst weight ratio of 10-80% by weight, but the amount is not specially limited thereto.
[0014] The mixing ratio of the tertiary amine and the saturated dicarboxylic acid is important in the present invention. The mixing ratio should be adjusted to obtain a pH value of 7.0 or higher of an aqueous solution of the mixture of the tertiary amine and the dicarboxylic acid. The aqueous mixture solution having a pH lower than 7.0 is highly corrosive, tending to corrode construction materials such as the catalyst storage vessel and the reaction apparatus. The upper limit of the pH of the aqueous solution of the mixture is not specially limited. However, with an insufficient amount of the saturated carboxylic acid mixed, the blocking of the amine by the acid is insufficient, not giving desired delaying effect. The reactivity and the reaction profile of the polyurethane formulation is adjusted by adjusting properly the amount of the saturated dicarboxylic acid so that the pH of the aqueous solution of the mixture is 7.0 or higher.
[0015] The tertiary amine used for formation of a mixture with a saturated dicarboxylic acid in the present invention may be any tertiary amine employed usually as a catalyst in urethane formation reaction. The tertiary amine includes
N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylpropylenediamine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N″,N″-pentamethyl(3-aminopropyl)ethylenediamine, N,N,N′,N″,N″-pentamethyldipropylenetriamine, N,N,N′,N′-tetramethylguanidine, 1,8-diazabicyclo[5.4.0]undecene-7, triethylenediamine, N,N,N′,N′-tetramethylhexamethylenediamine, N-methyl-N′-(2-dimethylaminoethyl)piperazine, N,N′-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylaminoethyl) ether, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and 1-dimethylaminopropylimidazole.
[0032] Of these tertiary amines, particularly preferred are triethylenediamine, bis(2-dimethylaminoethyl) ether, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylhexamethylenediamine, dimethylcyclohexylamine, and 1,2-dimethylimidazole.
[0033] The catalyst of the present invention is useful for production of polyurethane by reaction, for example, of a polyol, and an organic polyisocyanate in the presence of the catalyst, and optionally of a blowing agent, a surfactant, a crosslinking agent, and other additives.
[0034] The catalyst of the present invention gives excellent delay effect and has low corrosiveness in the polyurethane production. The amount of the catalyst used in the reaction ranges usually from 0.01 to 10 parts, preferably 0.05 to 5 parts based on 100 parts of the polyol used. The catalyst of the present invention may be formed by adding the tertiary amine and the saturated dicarboxylic acid separately into a polyol premix.
[0035] In the production process of the present invention, a catalyst other than the mixture of the tertiary amine and the saturated dicarboxylic acid may be additionally used. The additional other catalyst may be any of known tertiary amines and quaternary ammonium salts. The tertiary amines include
N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylpropylenediamine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N″,N″-pentamethyl(3-aminopropyl)ethylenediamine, N,N,N′,N″,N″-pentamethyldipropylenetriamine, N,N,N′,N′-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-s-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, triethylenediamine, N,N,N′,N′-tetramethylhexamethylenediamine, N-methyl-N′-(2-dimethylaminoethyl)piperazine, N,N′-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylaminoethyl) ether, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and 1-dimethylaminopropylimidazole.
The additional tertiary amine is used in an amount ranging preferably from 0 to 3.0 parts by weight based on 1.0 part by weight of the mixture of the tertiary amine and the saturated dicarboxylic acid of the present invention, but is not specially limited thereto.
[0053] In the production process of the present invention, an organometallic catalyst may be used in combination with the saturated dicarboxylic acid salt of the tertiary amine. The organometallic catalyst includes stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, lead octanoate, lead naphthenoate, nickel naphthenoate, and cobalt naphthenoate. Of these, preferred are organotin catalysts, more preferred are stannous dioctoate, and dibutyltin dilaurate. The amount of the organometallic catalyst, when it is used in the present invention, ranges usually from 0.01 to 5.0 parts by weight, preferably from 0.05 to 3.0 parts by weight based on 100 parts by weight of the polyol. With the organometallic compound of not more then 0.05 part by weight, the formed polyurethane is liable to crack, whereas with 3.0 parts or more thereof, the formed polyurethane will shrink.
[0054] The delayed action catalyst of the present invention is useful for any of polyurethanes including flexible slab foams, flexible molded foams, semi-rigid foams, integral skin foams, rigid foams, and polyurethane elastomers.
[0055] The polyol used in the present invention includes conventional known polyols such as polyetherpolyols, polyesterpolyols, and polymer polyols; and flame-retardant polyols such as phosphorus-containing polyols and halogen-containing polyols. The polyols may be used singly or in combination of two or more thereof.
[0056] The polyetherpolyol can be produced from a compound having-two or more active hydrogens as a source material, including polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythrithol; amines such as ethylenediamine; alkanolamines such as ethanolamine, and diethanolamine; by addition thereto of an alkylene oxide such as ethylene oxide and propylene oxide according to a method, for example, shown in Polyurethane Handbook (written by Gunter Oertel) pages 42-53. Particularly preferred are polyols produced from glycerin as the starting material and having a molecular weight ranging from about 3000 to about 12000.
[0057] The polyesterpolyol includes those derived by treating byproducts or wastes in production of nylon, TMP, pentaerythritol, and phthalate polyesters as shown in Polyurethane Resin Handbook (written by Keiji IWTA).
[0058] The polymer polyol includes those derived by reacting a polyol with an ethylenic unsaturated monomer such as butadiene, acrylonitrile, and styrene in the presence of a radical polymerization catalyst as shown in Polyurethane Handbook (written by Gunter Oertel), pages 75-76. In particular, the polymer polyols having a molecular weight ranging from 5000 to 12000 are preferred.
[0059] The polyisocyanate employed in the present invention may be any known organic polyisocyanate, including aromatic polyisocyanates such as toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanate such as dicyclohexyl diisocyanate, and isophorone diisocyanate; and mixtures thereof. The TDI and its derivatives include mixtures of 2,4-toluene diisocyante and 2,6-toluene diisocyante, and TDI-terminated isocyanate prepolymer derivatives. The MDI and its derivative include mixtures of MDI and its polymer of polyphenyl-polymethylene diisocyanate, and/or diphenylmethane diisocyanate derivatives having terminal isocyanate groups. In flexible foam production, particularly preferred are mixtures of TDI and MDI. In production of semi-rigid foams, integral skin foams, and rigid foams, particularly preferred is MDI.
[0060] The isocyanate index in the present invention is usually in the range from 70 to 130 in production of flexible foams, semi-rigid foams, and integral skin foams, and in the range from 70 to 250 in production of rigid foams and urethane elastomers, but is not specially limited thereto.
[0061] A blowing agent may be used, if necessary, in the present invention. Water and/or a halogenated hydrocarbon are useful as the blowing agent. The halogenated hydrocarbon includes known halogenated methanes and halogenated ethanes such as methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, dichlorotrifluoroethane, and dichloromonofloromethane. Water is particularly preferred as the blowing agent, an is used in an amount usually 2 parts by weight or more, preferably ranging from 3.0 to 8.0 parts by weight based on 100 parts by weight of the polyol depending on the intended density of the foam.
[0062] A foam stabilizer may be used, if necessary, in the present invention. Known organic silicone type surfactants are useful in the present invention, being used in an amount ranging usually from 0.1 to 10 parts by weight based on 100 parts by weight of the polyol.
[0063] A crosslinking agent or a chain extender may be additionally used, if necessary, in the present invention. The crosslinking agent or chain extender includes polyhydric alcohols of a low molecular weight such as ethylene glycol, 1,4-butanediol, and glycerin; amine polyols of a low molecular weight such as diethanolamine, and triethanolamine; and polyamines such as ethylenediamine, xylylenediamine, and methylenebis(o-chloroaniline). Of these, diethanolamine, and triethanolamine are preferred.
[0064] Further, other known additives may be used, such as a coloring agent, a flame-retardant, an age resister, and the like. The additive is used in a known manner in an usual amount.
[0065] The delayed action catalyst of the present invention is capable of delaying the initiation of the foam-forming reaction after mixing of the source materials, a polyol and an organic diisocyanate, since the initial activity of the catalyst is lower. Thereby, the liquid mixture is readily handleable and is sufficiently flow able to enable the source material liquid to distribute to corners of a large mold.
[0066] The catalyst of the present invention increases its activity with the temperature rise of the reaction mixture during progress of the foam formation reaction. Thereby, the catalyst activity increases remarkably to distribute the bubbles formed by the urethane reaction throughout a complicated mold without formation of a defective portion, and to increase the rate of curing of the foam to shorten the demolding time, improving remarkably the productivity.
[0067] The delayed action catalyst of the present invention corrode little the metal materials such as the catalyst vessel, the foaming apparatus, and other apparatuses, thereby improving the productivity.
EXAMPLES
[0068] The present invention is explained specifically by reference to Examples and Comparative Examples without liming the invention thereto.
[0069] Examples are shown for comparison of the catalysts of the present invention with conventional delayed action catalysts.
Examples 1-5 and Comparative Examples 1-7
[0070] The organic acid and triethylenediamine (TEDA, produced by Tosoh Corp.) were mixed in the prescribed ratio, as shown in Table 1. The mixture was diluted with pure water to the mixture concentration of 10% by weight.
[0071] Several iron nails were washed with hydrochloric acid, and weighed accurately. About 11 g of the nails were immersed in each of the above aqueous sample solutions, and left standing at room temperature. After four weeks, the iron nails were taken out, washed to remove the rust, and weighed. The corrosiveness of the sample was evaluated by the weight decrease of the nail. The results are shown in Table 1.
[0072] The sample solution of Examples 1 and 3 had a pH lower than 7.0, being corrosive and causing significant change of the weight of the nails, whereas the sample solutions of Examples 2, 4, and 5 had a pH higher than 7.0, being little corrosive, and causing no weight decrease of the iron nails.
[0073] On the other hand, the sample solutions employing succinic acid, or malonic acid shown in Comparative Examples. 1 and 2 caused significant weight decrease although the pH of the solution is higher than 7.0.
[0074] The sample solutions employing formic acid, acetic acid, 2-ethylhexanoic acid, citric acid, or malic acid caused significant weight decrease, being corrosive even though they have a pH higher than 7.0 respectively, as shown in Comparative Examples 3-7. The delayed action catalyst containing formic acid, acetic acid, or 2-ethylhexanoic acid does not exhibit the delaying effect when the amount of the acid is decreased to obtain a pH higher than 7.0 of the sample solution, as mentioned above.
[0075] Next, examples are shown in which the catalyst of the present invention or a conventional delayed action catalyst is employed for production of a flexible polyurethane foam or a rigid polyurethane foam.
Example 6
[0076] A prescribed amounts of triethylenediamine (TEDA, produced by Tosoh Corp.), adipic acid, and triethylene glycol as the organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 70° C. in a nitrogen atmosphere to obtain a complete solution of a liquid catalyst composed of triethylenediamine and the organic carboxylic acid (Catalyst T-AD).
Example 7
[0077] A liquid catalyst containing triethylenediamine and an organic carboxylic acid was prepared in the same manner as in Example 6 except that suberic acid was used as the organic carboxylic acid (Catalyst T-SB).
Example 8
[0078] A liquid catalyst containing triethylenediamine and an organic carboxylic acid was prepared in the same manner as in Example 6 except that sebacic acid was used as the organic carboxylic acid (Catalyst T-CB).
Comparative Example 8
[0079] A prescribed amounts of triethylenediamine, and ethylene glycol as the organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 50° C. in a nitrogen atmosphere to obtain a complete solution. Thereto, prescribed amounts of 95% formic acid and 2-ethylhexanoic acid were added dropwise from a dropping funnel by cooling the round-bottomed flask to obtain a liquid catalyst composed of trithylenediamine and the organic carboxylic acid (Catalyst T-F).
Comparative Example 9
[0080] A liquid catalyst containing triethylenediamine and an organic carboxylic acid was prepared in the same manner as in Comparative Example 8 except that citric acid was used as the organic carboxylic acid (Catalyst T-K).
Comparative Example 10
[0081] A liquid catalyst containing triethylenediamine and an organic carboxylic acid was prepared in the same manner as in Comparative Example 8 except that malic acid was used as the organic carboxylic acid (Catalyst T-R).
Comparative Example 11
[0082] Prescribed amounts of triethylenediamine (TEDA, produced by Tosoh Corp.), and ethylene glycol as the organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 50° C. in a nitrogen atmosphere to obtain a liquid triethylenediamine solution (Catalyst T-L).
[0083] Table 2 summarizes the compositions of the prepared catalysts, and symbols thereof.
Examples 9-11 and Comparative Examples 12-15
[0084] Flexible polyurethane foams were prepared from the combination of the polyol and the polyisocyanate (isocyanate index: 105) shown in Table 3 by use of the catalyst prepared in Examples 6-8 and Comparative Examples 6-11 with a blowing agent and a foam stabilizer as shown in Table 3. The flexible polyurethane foam compositions were measured and evaluated for the reactivity for formation of polyurethane foam (cream time, gel time, and rise time), the delaying effect (delaying time in seconds of the cream time with the catalyst in comparison with that of Catalyst T-L), the properties (density and air-flowability) of molded foam products. The evaluation results are shown in Table 3.
[0085] As shown in Table 3, the delayed action catalyst of the present invention delays the initial reaction (cream time) in comparison with the conventional catalyst not blocked by an acid. The delaying effect was found to be more remarkable than that of the conventional delayed action catalyst blocked by formic acid. The catalyst of the present invention corrodes little the metal materials, and enables production of foams having a low density and a high air permeability. On the other hand, the catalyst employing citric acid or malic acid having a hydroxyl functional group exhibits the delaying effect, but produces foams having low air permeability and being poor in other foam properties.
[0086] Next, the delayed action catalyst employing pentamethyldiethylenetriamine was evaluated.
Example 12
[0087] A prescribed amounts of pentamethyldiethylenetriamine (TOYOCAT-DT, produced by Tosoh Corp.), adipic acid, and ethylene glycol as the organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 50° C. in a nitrogen atmosphere to obtain a complete solution of a liquid catalyst composed of pentamethylenediethylenetriamine and the organic carboxylic acid (Catalyst DT-AD).
Example 13
[0088] A liquid catalyst containing pentamethyldiethylenetriamine and an organic carboxylic acid was prepared in the same manner as in Example 12 except that suberic acid was used as the organic carboxylic acid (Catalyst DT-SB).
Example 14
[0089] A liquid catalyst containing pentamethyldiethylenetriamine and an organic carboxylic acid was prepared in the same manner as in Example 12 except that sebacic acid was used as the organic carboxylic acid (Catalyst DT-CB).
Comparative Example 16
[0090] A prescribed amounts of pentamethyldiethylenetriamine and ethylene glycol as the. organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 50° C. in a nitrogen atmosphere to obtain a complete solution. Thereto, a prescribed amount of 95% formic acid was added dropwise from a dropping funnel by cooling the round bottomed flask to obtain a solution of a catalyst composed of trithylenediamine and the organic carboxylic acid (Catalyst DT-F).
Comparative Example 17
[0091] Prescribed amounts of pentamethyldiethylenetriamine and ethylene glycol as the organic solvent were placed in a 500-mL round bottomed glass flask equipped with a stirrer, and were mixed by stirring at 50° C. in a nitrogen atmosphere to obtain a pentamethyldiethylenetriamine solution (Catalyst DT-L).
[0092] Table 4 summarizes the compositions of the prepared catalysts, and symbols thereof.
Examples 15-17 and Comparative Examples 18-19
[0093] Rigid polyurethane foams were prepared from the combination of the polyol and the polyisocyanate (isocyanate. index: 110) shown in Table 5 by use of the catalyst prepared in Examples 12-14 and Comparative Examples 16-17 with a blowing agent and a foam stabilizer as shown in Table 4. The rigid polyurethane foam compositions were measured and evaluated for the reactivity (cream time, gel time, and rise time), the delaying effect (delaying time in seconds of the cream time with the catalyst in comparison with that of catalyst DT-L), the curing rate (Shore C hardness, 3 minutes after bubble formation), and the density of the foamed products. The evaluation results are shown in Table 5.
TABLE 1 Amine/Organic acid Weight change pH of sample Organic acid Tertiary amine (mol/mol) (%) solution (25° C.) Example 1 Adipic acid TEDA * 1.00/1.00 −3.61 3.8 2 Adipic acid TEDA 1.00/0.48 0 7.3 3 Suberic acid TEDA 1.00/1.00 −3.14 4.1 4 Suberic acid TEDA 1.00/0.48 0 7.4 5 Sebacid acid TEDA 1.00/0.40 0 8.1 Comparative Example 1 Oxalic acid TEDA 1.00/0.48 −2.69 7.2 2 Malonic acid TEDA 1.00/0.48 −2.12 7.2 3 Formic acid TEDA 1.00/0.98 −0.79 7.3 4 Acetic acid TEDA 1.00/0.98 −0.47 7.2 5 2-Ethylhexanoic acid TEDA 1.00/0.98 −0.14 7.4 6 Citric acid TEDA 1.00/0.33 −2.19 7.2 7 Malic acid TEDA 1.00/0.48 −3.00 7.3 * TEDA: Triethylenediamine
[0094]
TABLE 2
Example
Comparative Example
6
7
8
8
9
10
11
Catalyst Symbol
T-AD
T-SB
T-CB
T-F
T-K
T-R
T-L
Triethylenediamine
21.6
21.0
21.3
31.5
28.0
28.0
33.3
Adipic acid
13.9
Suberic acid
16.2
Sebacic acid
15.2
95% Formic acid
9.1
2-Ethylhexanoic acid
13.5
Citric acid
16.1
Malic acid
16.1
Ethylene glycol
64.5
62.8
63.5
45.9
55.9
55.9
66.6
[0095]
TABLE 3
Example
Comparative Example
9
10
11
12
13
14
15
Formulation
Polyol A 1)
60
60
60
60
60
60
60
Polyol B 2)
40
40
40
40
40
40
40
Diethanolamine 3)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Triethanolamine 4)
2.0
2.0
2.0
2.0
2.0
2.0
2.0
TM80 5)
46.9
46.9
46.9
46.9
46.9
46.9
46.9
T-AD
2.05
—
—
—
—
—
—
T-SB
—
2.13
—
—
—
—
—
T-CB
—
0.45
1.86
—
—
—
—
T-F
—
—
—
1.24
—
—
—
T-K
—
—
—
—
1.60
—
—
T-R
—
—
—
—
—
1.80
—
T-L
—
—
—
—
—
—
0.83
Water
3.20
3.20
3.20
3.20
3.20
3.20
3.20
Foam stabilizer A 6)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Foam stabilizer B 7)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Index 8)
105
105
105
105
105
105
105
Reactivity (sec)
Cream time
16.4
16.6
15.2
13.2
15.0
13.2
11.8
Gel time
60
60
60
60
61
60
60
Rise time
86
82
82
82
77
81
83
Delaying effect (sec)
4.6
4.8
3.4
1.4
3.2
1.4
—
Foam Properties
Core density (Kg/m 3 )
41.8
42.3
42.4
41.5
41.1
41.7
42.0
Air permeability
Good
Good
Good
Good
Poor
Poor
Fair
1) Polyetherpolyol (OH number: 30 mgKOH/g, produced by Sanyo Chemical Industries, Ltd.)
2) Polymer polyol (OH number: 27.5 mgKOH/g, produced by Sanyo Chemical Industries, Ltd.)
3) Crosslinking agent
4) Crosslinking agent
5) A mixture of T-80 (TDI produced by Nippon Polyurethane Industry Co.) and MR-200 (crude MDI produced by Nippon Polyurethane Industry Co.): T-80/MR-200 = 80/20
6) Silicone type surfactant (produced by Toray Silicone Co.)
7) Silicone type surfactant (produced by Nippon Unicar Co.)
8) Isocyanate group/OH group (mole ratio) × 100
[0096]
TABLE 4
Example
Comparative Example
12
13
14
16
17
Catalyst Symbol
DT-AD
DT-SB
DT-CB
DT-F
DT-L
Pentamethyldiethylene-
35.3
33.4
31.7
50.5
50.0
triamine
Adipic acid
14.7
—
—
—
—
Suberic acid
—
16.6
—
—
—
Sebacic acid
—
—
18.3
—
—
95% Formic acid
—
—
—
20.8
—
Ethylene glycol
50.0
50.0
50.0
28.7
50.0
[0097]
TABLE 5
Example
Comparative Example
15
16
17
18
19
Formulation
Polyol A 1)
60
60
60
60
60
Polyol B 2)
30
30
30
30
30
Polyol C 3)
10
10
10
10
10
HCFC-141b
29
29
29
29
29
MR-200 4)
46.9
46.9
46.9
46.9
46.9
DT-AD
2.00
—
—
—
—
DT-SB
—
2.00
—
—
—
DT-CB
—
—
2.00
—
—
TOYOCAT-TE
0.90
1.10
1.15
1.00
1.00
DT-F
—
—
—
1.41
—
DT-L
—
—
—
—
0.50
Water
2.00
2.00
2.00
2.00
2.00
Foam stabilizer 5)
1.0
1.0
1.0
1.0
1.0
Index 6)
110
110
110
110
110
Reactivity (sec)
Cream time
9.1
9.4
9.4
7.6
7.6
Gel time
50
50
50
50
50
Tack free time
55
60
63
53
54
Rise time
84
82
85
77
83
Delaying effect (sec)
1.5
1.8
1.8
0.0
—
Curing rate
Shore C hardness
47
46
45
45
30
Foam Properties
Core density (Kg/m 3 )
22.5
21.8
22.1
21.9
22.5
1) Polyesterpolyol (OH number: 400 mgKOH/g, produced by Mitsui Toatu Chemicals, Inc.)
2) Aminepolyol (OH number: 472 mgKOH/g, produced by Takeda Chemical Industries, Ltd.)
3) Polyesterpolyol (OH number 327 mg/KOH, produced by Toho Rika K.K.)
4) Crude MDI (produced by Nippon Polyurethane Industry Co.)
5) Silicone type surfactant (produced by Nippon Unicar Co.)
6) Isocyanate group/OH group (mole ratio) × 100
|
A catalyst for polyurethane production is provided which is non-corrosive and exhibits effective delay of catalyst action. The catalyst comprises a mixture of a tertiary amine, and a saturated dicarboxylic acid represented by General Formula:
HOOC—(CH 2 ) n —COOH
where n is an integer of from 2 to 14.
| 2
|
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/520,913, which was filed on Nov. 17, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to intake screens to exclude material from entering a water inlet, and is particularly directed to a self-cleaning intake screen.
BACKGROUND OF THE INVENTION
[0003] Self-cleaning intake screens are well known in the art. The earliest of such devices simply employed some mechanism to cause the screen, generally cylindrical in shape, to rotate within the stream or waterway. A water vacuum is generated inside the cylindrical screen, drawing water through the screen for filtration. As the screen rotates, any debris trapped on its upstream side would be washed away as it turns downstream. More sophisticated devices employ some sort of backwash system which, either continually or at periodic intervals, spray a high pressure jet of water or air against the screen in an attempt to blow debris off of and away from the outside of the screen. However, most self-cleaning intake screen designs are complicated and/or do not effectively keep the screen free from debris.
[0004] More recently, brushes and scrapers have been added to the outside of cylindrical screens, to scrape off debris and silt from the outer surface of the screen as the screen rotates, so that water flow through the screen to the interior of the screen is not unnecessarily impeded. However, for many applications, the interior of the screen still experiences an intolerable build up of debris and silt. For example, one application involves a screen made of wedge wires, which are thick wire strands that extend circumferentially around a support structure. The support structure includes longitudinally extending support members that are attached to the inside surface of the wedge wire screen, and are spaced one or several inches apart. It has been found that an external brush sweeping across the outer surface of the wedge wire screen fails to adequately clean the inside surface of the wedge wire and the support members, as well as possibly the laterally facing surfaces of the wedge wires. Spacing the support members further apart can reduce silt buildup, but then the screen no longer has the desired structural integrity, and the cylinder can lose its roundness as the wedge wire tends to lie flat between the support members.
[0005] It is also known to place a spirally oriented, motorized cleaning brush on the inside surface of a rotating cylindrically shaped screen, where the brush rotates in the opposite direction as the moving direction of the screen. However, such motorized cleaning brushes will not work with wedge wire type screens such as the one described above, because the brush will continually encounter the support members, which are not flush with the inside surface of the wedge wire screen. Thus, any brushes designed to clear the support members will not adequately clean the interior and lateral surfaces of the wedge wire. Moreover, it is expensive and difficult to include a separate motor, inside the cylindrical screen, to operate the rotating brush.
[0006] There is a need for an intake screen that reliably and effectively cleans itself, even its interior surfaces, without adding the complexity of additional motors.
SUMMARY OF THE INVENTION
[0007] The present invention solves the aforementioned problems by providing a self-cleaning screen that automatically cleans both the inside and outside surfaces of the cylindrical screen using only the rotation of the cylindrical screen itself. This is accomplished by using a fixed brush on the exterior surface of the screen, and a freely rotating brush on the interior surface of the screen, where the freely rotating brush is driven by the movement of the screen itself.
[0008] The invention can be implemented in numerous ways, including as a method, system, and device. Various embodiments of the invention are discussed below.
[0009] In one embodiment of the invention, a self-cleaning intake screen comprises a rotatable intake screen configured to filter material from a flow of water, the intake screen having openings for passing the flow of water. Also included is a first cleaning element operatively coupled to the intake screen so as to remove the material from the openings during rotation of the intake screen.
[0010] In another aspect of the present invention, a self-cleaning intake screen includes a manifold, a cylindrically shaped screen defining a plurality of openings and rotatably mounted to the manifold, and a first cleaning element rotatably mounted to the manifold and engaged with the screen such that rotation of the screen causes rotation of the cleaning element.
[0011] In yet one more aspect of the present invention, a self-cleaning intake screen includes a cylindrically shaped manifold, a cylindrically shaped screen disposed around the manifold in a rotatable manner relative to the manifold, the screen defining a plurality of openings, a motor for rotating the screen around the manifold, and a first cleaning element rotatably mounted to the manifold and disposed between the manifold and the screen, the cleaning element engaged with an interior surface of the screen such that rotation of the screen causes rotation of the cleaning element.
[0012] Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a better understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is a cross-sectional side view of the self-cleaning intake screen of the present invention.
[0015] FIG. 2 is a cross-sectional end view of the self-cleaning intake screen of the present invention.
[0016] FIG. 3 is a perspective view of the suction manifold of the self-cleaning intake screen of the present invention.
[0017] FIGS. 4 and 5 are perspective views of the wedge wire surface and external brush of the self-cleaning intake screen of the present invention.
[0018] FIG. 6 is a perspective view of the interior of the self-cleaning intake screen of the present invention.
[0019] FIG. 7 is a top view of the internal brush of the self-cleaning intake screen of the present invention.
[0020] FIG. 8 is a perspective view of the suction manifold and internal brush of the self-cleaning intake screen of the present invention.
[0021] FIG. 9 is a perspective view of the wedge wire surface, external brush, and protruding bristles of the interior brush, of the self-cleaning intake screen of the present invention.
[0022] FIG. 10 is a cross-sectional side view of an alternate embodiment of the present invention.
[0023] FIG. 11 is an end view of the alternate embodiment of the present invention.
[0024] Like reference numerals refer to corresponding parts throughout the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present invention is self-cleaning intake screen assembly 1 , as shown in FIGS. 1 and 2 . The assembly 1 includes a cylindrical shaped screen 10 rotatably mounted to a suction manifold 12 , an external fixed brush 14 , and an internal rotating brush 16 . The entire assembly is designed to be submerged under water, where suction applied inside the suction manifold 12 draws water through the cylindrical screen 10 and the suction manifold 12 , where the screen 10 filters out contaminants from the water.
[0026] Suction manifold 12 is cylindrically shaped, having an open end 18 , a closed end 19 , and a cylindrically shaped sidewall 20 . A pump manifold 22 (attached to the intake side of a pump which is not shown) is connected to the suction manifold 12 , for drawing water through the screen 10 and the suction manifold 12 and eventually to the pump (not shown). The suction manifold 12 includes a plurality of apertures 24 formed in its cylindrical sidewall 20 through which water will flow, as better shown in FIG. 3 . The apertures 24 are evenly spaced to ensure a more even flow of water though various portions of screen 10 . Motor 26 is mounted to the closed end 20 of suction manifold 12 , and includes a rotating drive shaft 28 that extends through the suction manifold closed end 20 .
[0027] Screen 10 includes a first end plate 30 connected to the motor drive shaft 28 , a second end plate 32 with a plurality of rollers 34 attached thereto, and a sidewall 36 formed by wedge wire 38 extending circumferentially around a center of the screen 10 and supported by support members 40 that longitudinally extend between the first and second end plates 30 / 32 , as best shown in FIGS. 1 and 4 - 6 . Wires 38 are separated from each other to form small openings 39 therebetween through which the water flows (as best seen in FIG. 9 ). Screen 10 is disposed around suction manifold 12 , and is rotatably supported at one end by the motor drive shaft 28 and the other end by the rollers 34 (which engage the suction manifold cylindrical sidewall 20 ).
[0028] The external brush 14 includes bristles 42 supported by a support bracket 44 , as best illustrated in FIGS. 2-5 . Bristles 42 sweep across the outer surface of the screen sidewall 36 (wedge wire 38 ) as the screen 10 rotates relative to the suction manifold 12 .
[0029] The internal brush 16 includes a shaft 46 rotatably mounted to the suction manifold 12 via brackets 48 , and bristles 50 extending from the shaft 46 preferably, but not necessarily, in a spiral fashion, as best illustrated in FIGS. 2 and 7 . Brackets 48 can be incorporated as end plates of a unitary trough or tray 52 for integrity, as best shown in FIGS. 3 and 8 . The brush 16 is positioned to engage with the interior surface of screen sidewall 36 (wedge wire 38 and support members 40 ).
[0030] In operation, motor 26 rotates screen 10 relative to suction manifold 12 . As screen 10 rotates, bristles 42 of fixed external brush 14 slide across the outer surface of sidewall 20 (i.e. outer surface of wedge wire 38 ) dislodging material such as debris and silt therefrom. Also, as screen 10 rotates, the support members 40 act as gear teeth by engaging with and rotating internal brush 16 . As internal brush 16 rotates, its bristles 50 engage with support members 40 and inner and side surfaces of wedge wire 38 , even poking through the wedge wire 38 as illustrated in FIG. 9 . This engagement wipes and dislodges debris and silt from the support members 40 and the inner/side surfaces of wedge wire 38 . By rotating with the passing support members 40 (in a passive manner), the internal brush 16 effectively cleans the interior of the screen 10 in a manner that the external fixed brush 14 can not. Also, by passively rotating internal brush 16 using the rotation of screen sidewall 36 , a second motor and/or complicated gearing is avoided. Thus, the rotation of screen 10 operates both brushes (one fixed and one rotating) without the need for any additional motors or moving parts.
[0031] The preferred embodiment includes a pair of screen assemblies 1 mounted to a single pump manifold. Hoist mechanisms can be used to lower and raise the intake screen assembly into a waterway for use. Components with dissimilar metals are electrically isolated to prevent electrolysis.
[0032] One of skill will realize that the invention is not limited to the embodiment described above. Rather, alternate embodiments exist. FIGS. 10-11 illustrate one such alternate embodiment. The embodiment of FIGS. 10-11 highlights the fact that the invention is not limited to configurations in which the brush 16 is rotated only by its bristles 50 . Rather, here, the brush 16 has a gear 100 that is aligned with a complementary rack 102 that is positioned along the inner surface 104 of the screen 10 , and whose teeth 104 are configured to interlock with the teeth of the gear 100 in a rack-and-pinion type arrangement. Accordingly, rotation of the screen 10 and rack 102 also induces rotation of the gear 100 and thus the brush 16 . In this embodiment, the bristles 50 need not frictionally engage against the screen 10 , as the brush 16 is turned by the rack 102 and gear 100 . This reduces wear on the bristles 50 and extends the useful life of the brush 16 .
[0033] It is to be understood that the present invention is not limited to the above embodiments, but includes others besides those already disclosed above. For example, the internal brush 16 is simply coupled to the screen 10 so that rotation of the screen 10 also moves the internal brush 16 against the screen 10 . The brush 16 need not be moved specifically by its bristles 50 , but instead can be moved by rotation of the screen 10 in any appropriate manner. The use of passively rotating internal brush 16 need not be used in conjunction with a suction manifold for applications where even water flow through the screen 10 is not needed. While internal and external brushes 14 / 16 are shown as mounted in an opposing fashion (on either side of the screen sidewall 36 ), such an opposing relationship is unnecessary. The screen sidewall 10 need not be formed of wedge wire 38 and support members 40 , but can be formed of any mesh or other known screen materials (i.e. thin wires to thick wires that resemble rigid bars) that provide the desired filtration of water flowing therethrough and can engage and rotate the internal brush 16 . The internal and external brushes 14 / 16 need not be brushes with protruding bristles 50 / 42 , but can be any cleaning element capable of removing material from the intake screen 10 , such as scrubbing pads or the like. In particular, the internal brush 16 can be a cleaning element having any configuration that allows it to engage against the intake screen 10 so as to induce rotation. The flow of water can be reversed from that shown, in which case the support members 40 are preferably on the outside of the screen as is the rotating brush 16 , and the fixed brush 14 is mounted inside the screen. The spacing and sizes of holes 24 can be varied to create more even flow. And, brush 16 can be freely disposed in tray 52 , without the ends thereof being rotatably attached to the tray ends.
[0034] Thus, the foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
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A self-cleaning screen that automatically cleans both the inside and outside surfaces of the cylindrical screen using only the rotation of the cylindrical screen itself. This self-cleaning ability is accomplished by using a fixed brush on the exterior surface of the screen, and a freely rotating brush on the interior surface of the screen, where the freely rotating brush is driven by the movement of the screen itself.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a muzzle brake for firearms and more particularly to a muzzle brake for firearms that decreases the amount of noise perceived by the shooter.
[0003] 2. Background Information
[0004] When a high-powered rifle is fired, the gas that ejects the projectile out of the end of the firearm accumulates behind the projectile and upon discharge from the firearm creates a recoil force back towards the shooter. This recoil force can be quite severe, especially in high-powered rifles, and results in pain, discomfort, and fatigue to the shooter. To reduce these side effects, “muzzle brakes” are used to lessen this recoil force back towards the shooter.
[0005] Most muzzle brakes comprise an attachment placed on the muzzle end of a firearm which reduces recoil by dissipating propellant gasses radially from the direction of the barrel of the firearm through a series of openings within the attachment. In deflecting the gas away from the end of the barrel, some of the gas impinges on the opening surfaces on the muzzle brake itself and is reflected back towards the shooter. This reflection directs more sound energy from the muzzle blast back toward the shooter. Thus, firearms equipped with conventional muzzle brakes often sound much louder to the shooter than the same firearm with no muzzle brake. Hence, one must choose either increased recoil force or increased noise in order to operate the firearm. What is needed is a muzzle brake that functions to reduce the recoil force felt by the shooter without a substantial increase in noise perceived by the shooter.
[0006] Accordingly, it is an object of the invention to reduce the recoil force felt upon discharge of a firearm in a manner that is significantly more quiet than existing muzzle brakes.
[0007] Additional objects, advantages, and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
[0008] The present invention is a muzzle brake device for reducing recoil and limiting noise upon the discharge of a firearm having a muzzle. One embodiment of the present invention is made up of a cylinder having: a first end adapted for attachment to the muzzle of a firearm, an outer surface extending from the first end to a second end along a longitudinal axis, a central bore of a desired diameter extending through the cylinder along the longitudinal axis, a plurality of radial gas holes extending from the central bore to the outer surface and generally linearly disposed along the longitudinal axis within the outer surface, at least one channel within the outer surface that connects a first gas hole to a second gas hole longitudinally proximate to the first gas hole, and the second gas hole to a third gas hole longitudinally proximate to the second gas hole. This combination creates at least one opening extending radially from the central bore to the outer surface having a longitudinal dimension greater than a lateral dimension.
[0009] In use, when a projectile proceeds out through the invented muzzle brake the resulting gasses are dispersed radially, away from the direction of the barrel of the firearm. The openings formed by the combination of channels and gas holes facilitates the dispersion of these gasses away from the muzzle brake in such a manner whereby the reflection of gasses off the muzzle brake and back towards the shooter is reduced. This reduction in reflected gasses correlates with a significant decrease in noise perceived by the shooter when using this muzzle brake compared to other muzzle brakes.
[0010] Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a perspective view of a first embodiment of the present invention.
[0012] [0012]FIG. 2 is an elevational view of the embodiment shown in FIG. 1
[0013] [0013]FIG. 3 is an elevational view of a second embodiment of the present invention.
[0014] [0014]FIG. 4 is a perspective view of the embodiment shown in FIG. 3.
[0015] [0015]FIG. 5 is an elevational view of a third embodiment of the invention.
[0016] [0016]FIG. 6 is a perspective view of the embodiment of the invention shown in FIG. 5.
[0017] [0017]FIG. 7 is a perspective view of a fourth embodiment of the invention
[0018] [0018]FIG. 8 is an elevational cross-sectional view of a typical prior art muzzle brake showing the reflection of gasses back towards the shooter
[0019] [0019]FIG. 9 is an elevational cross-sectional view of the present invention showing a decrease in the reflection of gasses back towards the shooter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0021] The present invention is a muzzle brake for reducing recoil and noise occasioned by the discharge of a firearm. Referring initially to FIG. 1, a first embodiment of the present invention is shown. The invented muzzle brake 10 is made up of a body, preferably a cylinder although any shape may be used, having an outer surface 12 extending from a first end 14 configured for connection to the muzzle of a firearm (not shown) to a second end 16 along a longitudinal axis L. A central bore 18 of a desired diameter extends therethrough along the longitudinal axis L of the cylinder. A series of radial gas holes 20 , 20 ′, 20 ″ extend from the first end 14 along the longitudinal axis L in a linear fashion towards the second end 16 . Each radial gas hole 20 , 20 ′, 20 ″ extends from the central bore 18 to the outer surface 12 .
[0022] In this embodiment, between the gas holes 20 , 20 ′, 20 ″ closest to the first end 14 are a series of channels 22 , within the outer surface 12 . These channels 22 connect a first gas hole 20 to a second gas hole 20 ′ generally linearly longitudinally disposed from the first gas hole 20 and a second gas hole 20 ′ to a third gas hole 20 ″ generally linearly longitudinally disposed to the second gas hole 20 ′. While the gas holes 20 extend from the outer surface 12 to the central bore 18 , in this embodiment the channels 22 in the outer surface do not extend all the way to the central bore 18 . The combination of the channels 22 and the gas holes 20 , 20 ′, 20 ″ forms an opening 30 in the outer surface of the muzzle brake 12 having a volume greater than the volume of a single gas hole 20 alone.
[0023] While in this embodiment the body and the holes are shown to be cylindrical in shape, it is to be distinctly understood that any shape may be used for the body, holes, channels or opening as long as the longitudinal dimension of the opening is greater than the lateral dimension of that opening. The shape of the body shown is cylindrical to allow for ease in manufacturing and to conform with the customary use of cylindrical shaped muzzle brakes in the art. However, the shape of the body is not limited to a cylinder alone.
[0024] In use, when the firearm is discharged, the gasses propelling the projectile exit the muzzle brake 10 though the radial gas holes 20 and are dispersed away from the longitudinal axis of the muzzle brake. The openings 30 formed by the combination of the gas holes 20 and the channels 22 have a greater longitudinal dimension and a larger area than the single gas holes 20 located near the second end 16 of the muzzle brake 10 . As a result, when the propellant gasses are dispersed, more of the gasses are dissipated through the longer opening 30 away from the direction of barrel of the firearm and less of the gasses are reflected back toward the shooter. The reduction in the reflection of gasses correlates to a reduction in noise perceived by the shooter upon discharge of the firearm.
[0025] [0025]FIG. 2 shows an elevational view of the embodiment shown in FIG. 1, further showing the position of a means for attaching 24 the muzzle brake 10 to a firearm. In this embodiment the means of attachment 24 is a threaded means, however such an attachment may also be accomplished by a coupling or any other means sufficient to adequately connect the muzzle brake to the muzzle end of a firearm including those typical in the prior art. It is to be understood that the gas holes on the surface of the cylinder 20 are disposed radially around the entire outer surface of the cylinder 12 .
[0026] [0026]FIG. 3 shows an elevational view of a second embodiment of the present invention. This second embodiment comprises a body 40 having an outer surface 42 , a first end 44 extending to a second end 46 along a generally longitudinal axis L, and a central bore 48 passing therethrough along the generally longitudinal axis. The first end 44 of the body 40 contains a means for attaching 54 the muzzle brake to a firearm. The second end 46 of the body 40 is adapted to discharge a projectile though the central bore 48 . The outer surface of the body 42 has a series of radial gas holes 50 , 50 ′, 50 ″ linearly disposed along the generally longitudinal axis L. Each radial gas hole 50 , 50 ′, 50 ″ has a perimeter 56,56′, 56″ extending from the central bore 48 to the outer surface 42 .
[0027] The radial gas holes 50 , 50 ′, 50 ″ closest to the first end 44 are interconnected by drilling the radial gas holes 50 , 50 ′, 50 ″ so that the perimeter 56 of a first radial gas hole 50 overlaps the perimeter 56′ of a second radial gas hole 50 ′ lying generally linearly longitudinally proximate to the first radial gas hole 50 , and that the perimeter 56′ of the second radial gas hole 50 overlaps with the perimeter 56″ of a third radial gas hole 50 ″ longitudinally linearly proximate to the second radial gas hole 50 ′. This combination of a first radial gas hole 50 , a second radial gas hole 50 ′ and a third radial gas hole 50 ″ all overlappingly interconnected at their respective perimeters creates an opening 60 having a greater longitudinal dimension and area than the opening of a single radial gas hole 50 alone. Hence, when a projectile is discharged through the central bore 48 ; the gasses accompanying the projectile are disbursed radially away from the central bore 48 . The increased size of the openings 60 nearest to the first end 44 of the firearm facilitates the radial dispersion of propellant gasses whereby less of the gasses are reflected back toward the shooter. This results in decreased noise perceived by the shooter of the firearm upon discharge.
[0028] [0028]FIG. 4 is a perspective view of the embodiment shown in FIG. 3.
[0029] [0029]FIG. 5 is an elevational view of a third embodiment of the invention. This embodiment is made up of a cylinder 70 having an outer surface 72 , a first end 74 extending to a second end 76 along a longitudinal axis, and a central bore 78 passing therethrough along a longitudinal axis. The first end 74 of the cylinder contains a means for attaching 84 the muzzle brake to a firearm. The second end 76 of the cylinder is adapted to discharge a projectile though the central bore 78 . The outer surface 72 of the cylinder has a series of linearly disposed radial gas holes 80 , 80 ′, 80 ″ that extend from the first end 74 of the muzzle brake to the second end 76 of the muzzle brake along a longitudinal axis L. Each radial gas hole 80 , 80 ′, 80 ″ has a perimeter 86,86′, 86″ and a passage that extends from the central bore 78 to the outer surface 72 of the cylinder.
[0030] In this embodiment, the radial gas holes 80 , 80 ′, 80 ″ closest to the first end 74 of the firearm are connected to form an opening 90 by drilling at least one channel pore 82 in the outer surface 72 of the cylinder. Each channel pore 82 extends from the outer surface 72 inward toward the central bore 78 but does not connect with the central bore 78 . Additionally, each channel pore has a perimeter 88. A first channel pore 82 is positioned so that the first channel pore perimeter 88 circumferentially overlaps both the perimeter of a first radial gas hole 86 and the perimeter 86′ of a second radial gas hole 80 ′ linearly disposed along the longitudinal axis from the first radial gas hole 80 .
[0031] Preferably, second channel pore 82 ′ is similarly formed between the second radial gas hole 80 ′ and a third radial gas hole 80 ″ by drilling a second channel pore 82 ′ so that the perimeter 88′ of a second channel gas hole 82 ′ overlaps the perimeter 86′ of the second radial gas hole 80 ′ and the perimeter 86″ of a third radial gas hole 80 ″ linearly disposed along the longitudinal axis from the second radial gas hole. This combination creates an opening 90 having a greater longitudinal dimension and area than the opening of a single radial gas hole 80 alone. Hence, when a projectile is discharged through the central bore 78 of the cylinder; the gasses accompanying the projectile are disbursed radially away from the central bore 78 outward. The increased size of the openings 90 nearest to the muzzle end of the firearm facilitate the dispersing of propellant gasses in such a manner whereby more of the gas is dissipated and less of the gas is reflected off the muzzle brake back towards the shooter. This results in decreased noise perceived by the shooter of the firearm upon discharge.
[0032] [0032]FIG. 6 shows a perspective view of the third embodiment shown in FIG. 5.
[0033] [0033]FIG. 7 shows the preferred, fourth embodiment of the invention. The invented muzzle brake is made up of a cylinder 110 having a circumvolving outer surface 112 extending from a first end 114 configured for connection to the muzzle end of a firearm (not shown) to a second end 116 along a longitudinal axis L. A central bore 118 of a desired diameter extends therethrough along the longitudinal axis L. A series of radial gas holes 120 , 120 ′, 120 ″ extend from the first or muzzle end of the firearm along the longitudinal axis in a linear fashion towards the second end 116 . Each radial gas hole has a periphery 121 and extends from the central bore 118 outward to the outer surface 112 .
[0034] Between the radial gas holes 120 closest to the first end 114 are a series of connecting pores 122 within the outer surface 112 . Each connecting pore 122 has a periphery 123 and extends from the central bore 118 to the outer surface 112 . A first connecting pore 122 is disposed near the first end 114 of the muzzle brake. The periphery 123 of the first connecting pore 122 overlaps the periphery of a first gas hole 120 . A second connecting pore 122 ′ having a periphery 123′ is disposed between the first gas hole 120 and a second gas hole 120 ′. The second gas hole 120 ′ also has a periphery 121′ and is linearly longitudinally disposed proximate to the first gas hole 120 . Whereby, the periphery of said second connecting pore 123 ′ overlaps the periphery 121 of the first gas hole 120 and the periphery 121′ of the second gas hole 120 ′. A third connecting pore 122 ″ having a periphery 123″ is disposed between the second gas hole 120 ′ and a third gas hole 120 ″ having a periphery 121″ and is linearly longitudinally disposed from said second gas hole 120 ′. Whereby the periphery of the third connecting pore 123 ″ overlaps the peripheries of both the second gas hole 121 ′and the periphery third gas hole 121 ″. The combination of the first connecting pore 122 , first gas hole 120 , second connecting pore 122 ′, second gas hole 120 ′, third connecting pore 122 ″ and third gas hole 120 ″ creates an opening 130 having a longitudinal dimension greater than the longitudinal dimension of a single gas hole 120 alone.
[0035] While in this embodiment the holes and pores are shown to be cylindrical in shape, it is to be distinctly understood that any shape may be used for the holes, channels, pores or openings as long as the longitudinal dimension of the resulting opening is greater than the lateral dimension of the same opening. Furthermore the size of the openings must be greater near the first end 114 of the muzzle brake and smaller near the second or discharge end 116 .
[0036] [0036]FIG. 8 shows a cross-section of a prior art embodiment showing the impact and reflection of gasses off of the surface of the muzzle brake device and back towards the shooter.
[0037] [0037]FIG. 9 shows a cross-section of the preferred fourth embodiment of the present invention showing the impact and reflection of gasses off of the muzzle brake. This figure also shows a means for attachment to a firearm 124 , and a circumvolving cut groove 131 extending from the means of attachment portion 124 to the opening 130 . This cut out groove or chamber 131 aids in the dispersion of gasses and reduces the amount of noise perceived by the shooter. When the firearm is discharged the gasses propelling the projectile exit the muzzle brake 110 though the openings 130 and are dispersed radially away from the longitudinal axis of the muzzle brake of the firearm. These openings 130 near the first end 114 , have a greater longitudinal dimension than those gas holes 120 located near the second end of the muzzle brake 116 , and facilitate the passage of gasses away from the muzzle brake in such a manner whereby reflection of gasses back toward the shooter is diminished. The reduction in the reflection of gasses correlates to a reduction in noise perceived by the shooter upon discharge of the firearm.
[0038] The gas dispersing capability and hence the reduction in noise by this muzzle brake is further enhanced by undercutting the inner surface of the central bore 118 to create a circumvolving cut out groove or chamber 131 which facilitates the radial dispersion of gasses away from the end of the gun, as shown in FIG. 9. The inclusion of this cut out groove results in a one-half decibel decrease in noise perceived by the shooter.
[0039] Comparing FIG. 8 to FIG. 9 we see that the amount of gas reflected back toward the shooter is substantially less in FIG. 9 than in FIG. 8. This reduction in reflected gasses correlates to a reduction in noise perceived by the shooter.
[0040] While several embodiments have been shown it is to be distinctly understood that combinations of the various features of the several embodiments may be combined to achieve the same desired result. Furthermore, while the shape of the muzzle brake is generally cylindrical it is to be distinctly understood that any shape or configuration may be used for the muzzle brake, the openings, gas holes, or central bore.
[0041] While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.
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A muzzle brake for dissipating a recoil force created by the discharge of a firearm having a muzzle, without a substantially increasing the noise heard by the shooter. The muzzle brake is a cylinder with at least one opening radially disposed from a central bore. These radial openings have a longitudinal dimension greater than a lateral dimension and help to dissipate force-causing gasses away from the muzzle end of a firearm with reduced reflection of gasses back towards the shooter. The decreased amount gas reflected back toward the shooter decreases the amount of noise the shooter hears.
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The present invention is in a garment interlining and a method for producing the same. More specifically the present invention is in an interlining for shirts, blouses and the like and are especially useful for shirt or blouse collars, cuffs and pocket flaps. Interlinings are fabric composites used to impart certain properties to particular areas of garments.
For garments such as shirts, an interlining should have certain desirable properties. The interlining, when bonded to the shirt or blouse material should provide some degree of stiffness but the garment should retain its handling characteristics. The interlining should also have good shape retention, especially after washing or dry cleaning and should, when fused to the garment material give a smooth surface appearance. It is thus necessary that the interlining have a good and uniform adhesion to the outer fabric.
For shirts, the interlinings are formed of a base material, such as a nonwoven material with a point bonding pattern, the upper surface of which has a number of adhesive dots. At least one of the surfaces of the base material is contoured or textured. The contoured surface includes depressions or pits and plateaus. These adhesive dots are on one of the contoured surfaces of the base material, including in the pits between adjacent plateaus, the plateaus and connecting borders.
However, it has been found that such interlinings are unsuitable because they often cause a streaking, i.e., an uneven outer surface appearance, in the completed garment. Due to the contoured arrangement of adhesive dots, a garment material or outer fabric fused to the base material will also acquire a corresponding contour. This contour is visible by the appearance of streaks in the finished outer surface of the garment. This problem becomes aggravated after washing, especially with heavier base materials, because the structure loosens up and can result in areas of the garment having a "puffed" appearance, thus emphasizing any such streaks.
SUMMARY OF THE INVENTION
The present invention avoids the above-described undesirable interlining characteristics and provides an interlining, which when fused to an outer fabric, gives a good surface smoothness and does not exhibit streakiness and retains its good appearance even after repeated washings.
The present invention is in a textile product for a shirt or blouse interlining formed of a bonded base material, preferably a point bonded nonwoven fabric, having bonded thereon a layer or a fleece containing adhesive fibers. A plurality of adhesive dots are applied on that surface of the fleece opposite to the surface bonded to the base material. The adhesive dots are substantially in a singular planar arrangement and, at least some of the dots, and preferably a majority of the dots, are separated from the base material by the fleece or layer. The interlining can be fused to a shirt fabric, such as a broadcloth or a variety of batistes, to provide a good and smooth surface appearance. With the product of the invention, the smooth surface appearance is retained even after washing.
The present invention is also in a method for producing the above-described interlining and product. In the method of the invention, a base material is provided, a layer or a fleece layer of adhesive fibers is deposited on a surface of the base material and bonded thereto. The adhesive dots are then applied to the bonded product on top of the fleece in a known manner.
While it is preferred that the base material be a nonwoven fabric which is point bonded, a suitable base material may also be produced by a water entanglement process. Also, the layer may be deposited on the surface of the base material as an extruded porous film. It is also possible to produce the base material by a combination of point bonding and ultrasonic techniques.
In a further aspect of the invention, the interlining is bonded to an outer fabric to provide a garment.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects obtained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a base material useful in the invention;
FIG. 2 shows a prior art construction;
FIG. 3 shows an interlining of the invention; and
FIG. 4 shows an interlining of the invention fused to an outer fabric.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows an upper section of a point bonded or textured nonwoven base material 10. The base material has a textured surface dependent upon the engraving of the point bonding pattern or other means of manufacturing such as water entanglement. The contoured or textured surface has spaced depressions or pits 12 separated by plateaus 14. Sloping walls or borders 16 extend from depressions 12 to the plateaus 14. The base material lower surface (not shown) may have a similar contour or texture.
The base material must be contoured or textured to obtain a textile handle in contrast to a paper-like feel. Preferably the base material is point bonded. Point bonding can be achieved by an engraved or gravured heated calender roller or ultrasonic bonding. Textured surfaces can be obtained by water entanglement, mechanical entanglement such as needling, or other techniques.
The base material 10 is of polyester. While the base material is preferably 100% polyester, it may contain up to about 90 wt.-% of one or more co-fibers such as rayon, Nylon 6, Nylon 6,6 and cotton. When the base material is of 100% polyester, it may optionally contain up to about 90 wt.-% of a copolyester, either as a homofil or heterofil.
When the base material is produced by water entanglement, it may contain up to 100 wt.-% of one or more cofibers such as rayon, Nylon 6, Nylon 6,6 and cotton. When the base material is of 100% polyester, it may optionally contain 100 wt.-% of a copolyester, either as a homofil or heterofil.
A highly preferred polyester is a polyethyleneterephthalate (PET), especially when the base material is 100% polyester. When the base material contains a heterofil, the second component can be a polybutyleneterephthalate (PBT). A 50% PET-PBT blend is especially preferred.
The base material should have a specific weight of at least 25 g/m 2 . Suitable nonwoven base materials are commercially available as from Freudenberg Nonwovens USA. A typical nonwoven base material has a thickness of approximately 13 mils. The combined depressions 12 are generally about 8 to 12 mils in depth.
FIG. 2 shows a prior art construction with adhesive dots 18 printed on one of the surfaces of base layer 10 in depressions 12, on the plateaus 14 and on the sloping walls 16. When an outer fabric layer, such as a broadcloth or a variety of batiste, is bonded to the construction of FIG. 2, the bonding is primarily by the adhesive dots. Due to non-planar orientation or contours of the applied adhesive dots, the end product can acquire a contoured surface pattern resulting in a non-smooth, streaky appearance. When washed, the bonded structure loosens and a puffiness can develop giving the streaks an even more pronounced streaky appearance. The heavier the base material, the more severe the problem after washing.
FIG. 3 shows an interlining of the invention. A fleece containing adhesive fibers 20 is deposited on to the base material of FIG. 1 in an amount of 6 to 40 gm/m 2 and preferably 10 to 25 g/m 2 . Preferably the weight of fleece layer 20, without the adhesive dots, is less than that of the base material, i.e., about 1/3 of that of the base layer. The amount of the fleece material is such that it at least covers the depressions 12 after bonding so as to provide a uniform surface. Preferably, the fleece is deposited so as to form a layer which covers the depressions (pits) and the plateaus.
Generally speaking, the fleece layer 20 can be of polyester fibers, polyolefin fibers (polyethylene, polypropylene) and mixtures thereof. More specifically, fleece layer 20 can be:
a) 100% polyester, preferably
b) polyester and 30 to 70 wt.-% polyethylene as a homofil fiber but can be up to 100% polyethylene;
c) polyester and polyester/polyethylene bicomponent fibers, up to 100% bicomponent fiber and preferably 70 to 100 wt.-% of bicomponent fibers;
d) polyester and polypropylene homofil fiber, up to 100% polypropylene homofil fiber, preferably 30% wt.-% polyester and 70 wt.-% polypropylene homofil fibers;
e) polyester and polyester/polypropylene bicomponent fibers, up to 100% bicomponent fiber and preferably 70 to 100 wt.-% of bicomponent fibers;
f) polyester together with copolyester homofil fibers, with 100% copolyester homofil fiber and preferably 30 wt.-% polyester and 70 wt.-% of the copolyester homofil fiber; and
g) polyester w/polyester copolyester bicomponent fiber, up to 100% bicomponent fiber and preferably 70 to 100 wt.-% of bicomponent fiber.
The fleece layer can be deposited on the base material by numerous techniques such as carding, air-laying, melt blowing, spun bonding and wet laying. A layer can also be deposited on the base material as an extruded porous film.
In a highly preferred embodiment, the polyester is PET. When a copolyester is used it is preferred to contain PET and PBT (blocked).
After the fleece layer 20 is applied onto the base material 10, the base material and fleece layer are subjected to heat and pressure, or other means of bonding, to form a bonded structure. The oven temperature is above the fleece fiber melting point but the calender temperature is below its melting point. Generally the oven temperature is in the range of 100° C. to 230° C. while the calender temperature is about 80° C. to 220° C. A pressure range of 10 to 80 kiloponds/cm is useful.
Subsequent to the bonding of the fleece to the base material, the adhesive is applied in a known manner such as by printing, powder point application, powdering or as an adhesive web. The adhesive is oriented in a planar arrangement so as to show little or none of the preexisting contours of the base material. At least some of the adhesive dots, and preferably a majority of the dots, are separated from the base material by the fleece.
FIG. 4 shows the interlining of FIG. 3 fused to an outer fabric 22 which may be a broadcloth or the like. The outer fabric 22 is fused to the interlining primarily through the adhesive dots 18 and, as shown in the Figure has a substantially even or smooth appearance not following the contour of the textured or contoured nonwoven.
EXAMPLE 1
A point-bonded nonwoven base material of 52 g/m 2 is provided. A fleece layer of 14 g/m 2 of 100% PET/PE S/C [sheath/core] bicomponent fibers is applied on top of the base material by carding. The base material and fleece layer are heated in a through air oven to about 140° C. and then press heated through a calender-roller at about 110° C. at about 40 kiloponds/cm. Adhesive dots of 23 g/m 2 of HDPE are then applied by paste printing to the top surface of the fleece layer.
The interlining has a pattern of adhesive dots on the fleece layer which is substantially planar. The majority of the dots were not in contact with the base material.
EXAMPLE 2
A point-bonded nonwoven base material of 45 g/m 2 of 100% PED is provided. A fleece layer of 16 g/m 2 of 50% PET and 50% polypropylene fibers is applied on top of the base material by carding. The base material and fleece layer are heated in a through air oven to about 160° C. and then press heated through a calender-roller at about 125° C. at about 40 kiloponds/cm. Adhesive dots of 20 g/m 2 of HDPE are then applied by paste printing to the top surface of the fleece layer.
The adhesive dots on the fleece layer were substantially planar. The majority of the dots are not in contact with the base material.
EXAMPLE 3
A point-bonded nonwoven base material of 35 g/m 2 of 90% PET and 10% Nylon is provided. A fleece layer of 14 g/m 2 of 60% PET and 40% polyethylene homofil fibers is applied on top of the base material by carding. The base material and fleece layer are heated in a through air oven to about 143° C. and then press heated through a calender-roller at about 110° C. at about 40 kiloponds/cm. Adhesive dots of 18 g/m 2 of HDPE are then applied by a powder point applicator to the top surface of the fleece layer.
The adhesive dots on the fleece layer were substantially planar. The majority of the dots were not in contact with the base material.
EXAMPLE 4
A point-bonded nonwoven base material of 52 g/m 2 of 100% PET is provided. A fleece layer of 18 g/m 2 of 100% PET/Co-PES bicomponent fibers is applied on top of the base material by carding. The base material and fleece layer are heated in a through air oven to about 200° C. and then pressed between heated calender rollers at about 180° C. at about 60 kiloponds/cm. Adhesive dots of 27 g/m 2 of HDPE are then applied by paste printing to the top surface of the fleece layer.
The adhesive dots on the fleece layer were substantially planar. The majority of the dots were not in contact with the base material.
It will be understood that the specification and examples are illustrative but not limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art.
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Disclosed is a textile product and a method for making that product for a shirt or blouse interlining formed of a bonded base material having bonded thereon a fleece of adhesive fibers. A plurality of adhesive dots are applied on that surface of the fleece opposite to the surface bonded to the base material. The dots are substantially in a singular planar arrangement and, at least some of the dots, are separated from the base material by the fleece. The interlining can be fused to a shirt fabric such, as a broadcloth, to provide a good and smooth surface appearance. With the product of the invention, the smooth surface appearance is retained even after washing.
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BACKGROUND OF INVENTION
This invention relates specifically to a wheeled apparatus for transporting skis and related equipment.
Skiers need to carry lots of equipment when they go to the slopes. If these people are parents with smaller children then they must also carry the little one's share. This can take lots of the fun out of the day's adventure. It can also be dangerous what with whirling skis and sharp ski poles. It seems that there is a need for a device which can safely transport a variety of ski equipment and be conveniently stored away in a very small area.
Parker, U.S. Pat. No. 5,340,153, discloses a ski carrier that will carry two pair of skis on a wheeled dolly similar to the type used to transport utility poles behind a truck. That is, attach one end of the long object to a pair of wheels and attach the opposite end to a vehicle.
Garvey Jr, U.S. Pat. Nos. 4,666,184 and 4,792,159 discloses a two wheeled carrier for a single pair of skis and Kybutz, U.S. Pat. No. 4,540,198 discloses a one wheel device for a single pair of skis. All of these devices are adequate for their intended uses but fall far short of the goal of this invention; to provide a multi-purpose cart that can not only carry three or more pair of skis, boots and poles but can also be used to carry other gear.
SUMMARY OF THE INVENTION
One object of the invention is to provide a carrier that will overcome the limitations of the prior art devices.
Another object of the invention is to provide a compact ski carrier that will transport three or more pairs of skis, boots and poles safely and easily to the desired location.
Like the aforementioned devices of Parker and Garvey and the utility pole carrier, the present invention comprises the concept of a two wheeled device attached to one end of a pair of skis. Unlike Parker's device, the current invention mounts the pair of skis in a rigid, non flexing on-edge position rather than on a flat and flexible position. This method affords much greater strength and a more secure attachment to the device. This on edge position prevents natural ski flexing movement which will scratch and eventually wear the finish and worse, loosen the skis from the device.
Unlike Parker, this invention also comprises a horizontal support structure which mounts at the center of a main or first pair of skis and supports two or more pairs of skis along with poles and boot bags etc. The on edge position of the main or first pair of skis also provides the horizontal support structure with a much more rigid surface area to grip. Parker's device as disclosed is not capable or transporting more than two pair of skis without major design changes. Furthermore, both pair of skis on Parker's device must be nearly the same length. This restricts the use to two people of the same height, which effectively eliminates parent and child, the group that would gain the most advantage from the invention.
Unlike Parker, who hangs the boots at the user's hand, the ski boots and other equipment carried by this invention are contained in readily available boot bags which can be carried in the cradle formed by the three pair of skis. The load is over the wheels of the device and not at the arm area of the user. This makes the weight of the boots negligible. The boots are secure and do not swing with the walking gait of the user as they would with Parker's device.
Like Parker, one embodiment of this invention comprises a handle, albeit optional, to pull the device along. Parker's handle is a multi piece affair which again mounts on the skis in a horizontal and flexing manner rather than a vertical and rigid manner. Again, the device will surely loosen over a period of rough and sustained pulling because of the nature of ski design.
When laid on a flat surface and viewed from the side all top surfaces of modern skis taper from thick in the middle boot binding area to thin at each end. The front tips then flare steeply upward and the tails flair slightly upward. Unless the handle and wheel device are attached with extreme torque, in exactly the right position, the push-pull action will begin to loosen the skis. Once this motion begins the shape of the ski will assist and accelerate the loosening process. This will inevitably scratch the skis' top face and ultimately detach the carrier.
Unlike Parker, this invention comprises a simple one piece handle which surrounds the sides and edges of the skis. The handle easily slides over the tails of the first pair of skis and installs in seconds. It can be placed in varying positions to suit the user. The design of modern skis coupled with the handle's unique design tightens the grip on the ski's side when the handle is pulled or lifted. As mentioned before the handle is optional and is used merely to enhance the pulling and gripping power on a fully loaded carrier. The invention will function in its basic application without the handle. Parker's device needs the handle to balance the loaded carrier.
The current invention's embodiment is both simple and easy to use. Unlike Parker's device, this invention can be easily attached to the first pair of skis at home and then transported to the ski area on the roof rack of the vehicle. Parker's device needs both pair of skis and the handle attached in order to provide stability when lifting the unit on or off the vehicle's rack, a heavy load for one person to lift.
This invention can be attached to the first pair of skis in the parking lot while standing upright rather than having to lay the device on the ground. This is because the carrier frame is formed in a T configuration. The user can easily hold the vertical section of the T and the first pair of skis in one hand while the other hand tightens the clamping device. From Parker's drawings it would appear that the device would have to be laid on the ground when trying to mount it to the skis. It further seems that it might require two people to accomplish this task.
As mentioned before, Parker mounts his skis on the flat. This method requires that the tips be located at the user end of the device. Otherwise, from the drawings it would appear that the ski tips of the bottom skis would flare downward reducing the ground clearance by about half. This would cause the tips to snag on rougher terrain with abrupt transitions like one finds at a ski area.
Further objectives and advantages will become evident as one studies the detailed description and drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows the invention carrying ski poles and boot bag with the first pair of skis mounted on edge with the horizontal support structure and optional pulling handle in place.
FIG. 1A shows top view of carrier loaded with two pairs of flanking skis and poles.
FIG. 2 shows a rear view of carrier in operating position with clamping assembly and flanking ski support bars extended.
FIG. 2A shows carrier in folded storage position.
FIG. 3 shows a top sectional view of the T shaped carrier in operating position.
FIG. 4 shows the carrier in isometric view without wheels.
FIG. 5 shows a rear view of rear flanking ski support bar.
FIG. 6 shows a folding axle assembly.
FIG. 6A shows the current embodiment's detail of the folding axle assembly.
FIG. 7 shows one embodiment of the ski carrier's three jaw ski clamping assembly.
FIG. 8 shows an embodiment of a horizontal support structure.
FIG. 9 shows an embodiment of a handle which can mount to the first pair of skis.
FIG. 9A shows a slightly different embodiment of the handle of FIG. 9.
FIGS. 10 and 10A show a four jaw embodiment of the ski clamping assembly.
FIG. 10B shows a different embodiment of the three jaw ski clamping assembly.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The carrying device is comprised of three main elements used in combination to form a ski carrying device:
1. A two wheeled component with attachment and support means for one end of a first pair of skis and support and attachment means for the ends of additional pairs of skis flanking the first pair of skis.
2. The first pair of skis form the frame of the carrying device.
3. A horizontal support structure placed mid section of the first pair of skis to support the opposite ends of the additional pairs of skis.
FIG. 1 shows the invention in its operating position. The inverted U shaped clamping assembly 10 detachably clamps the tip end of the first pair of skis to the wheeled component. Horizontal support structure 40 slips over the first pair of skis at the binding area and is held in position by friction. Handle 50, is slipped over the tails of the first pair of skis 1. However, this handle is not needed to achieve basic operation of the carrier.
In FIG. 1A, additional pairs of skis 2, are placed on edge upon the horizontal support structure 40 and on the rear flanking support bars 20. The combination of these three pairs of skis creates a cradle like area 5 where ski poles 3 and a boot bag 4 can be supported.
FIG. 2 shows a rear sectional view of the invention in operating position with the first pair of skis 1 attached by means of clamp assembly 10. When not in use, the invention can be folded for easy storage by pushing assembly 10 down through the T shaped frame 19 and folding the support bars 20 down to their resting position. FIG. 2A.
FIG. 3 is a top sectional view of the T shaped main frame of the carrier.
In FIGS. 6 and 6A, the axle mounting plate assembly 25 serves to both hold the axle to the main frame 19 and increase the carrier's ground clearance. The axle mounting plate assembly pivots to the folded position on shaft 24, FIG. 6. The inside walls and bottom of the channel 25' of the axle assembly rest against the side walls and bottom of the main frame 19. The weight of the carrier and its load keep the two assemblies effectively locked together forming a rigid, continuous bar. To permit the axle assembly to fold under at a 90 degree angle, the inner end section of the bottom of channel 25' has been removed. This section's length is approximately the same as the height of the side wall of frame 19.
FIG. 4 is one embodiment of a three jaw clamping assembly and FIG. 10b is another three jaw clamping assembly. FIG. 10 is a four jaw clamp. The clamp arms 12, are shaped like an inverted U and are very similar in operation. The arms of the inverted U shaped clamping device 10. FIG. 4 have slideable engagement with the mainframe 19 via two holes through its surface as does the four jaw assembly in FIG. 10. The cross view of the three jaw clamp, FIG. 7, shows clamping device arms 12 passing through mainframe 19 and lower clamping jaws 11, and secured with stopping element, a cotter key and washer 18. The clamp arms 12 can be secured in a number of ways, however the travel of the clamp arms 12 must be adjustable since widths of the first pair of skis will vary. Clamp arms 12 must be able to travel freely up and down in order to make attachment of the first pair of skis a simple process. All of the above applies to the four jaw assembly as well.
In FIG. 7 and FIG. 10 a threaded rod 15 is welded or other wise rigidly attached to the center of the U shaped clamp arms 12. The diameter of the threaded rod is slightly less than the diameter of the clamp arms 12. A threaded element, such as a spinner or knob 14, can travel up or down rod 15. A cavity in the bottom of spinner 14 houses a flange 13' which is a protrusion of top jaw 13. This flange is rather loosely housed to allow spinner 14 to rotate around threaded rod 15 and the flange 13'. As the spinner travels up rod 15 the lip of the cavity in 14 pulls up on the bottom lip of 13' thus pulling jaw 13 up and loosening the clamp. When the clamp is tightened the top of the cavity in 14 pushes down on the top of the flange and urges jaw 13 down on to the top edge of the first pair of skis 1.
For ease of operation jaw 13 should remain parallel with opposing jaws 11. This can be done by means of a key 17 in the flange 13' and a way or slot 16 in the threaded rod 15. As the cavity in spinner 14 moves jaw 13 up or down, it is natural that the flange 13' rotate in unison with the knob 14. However, the key 17 traveling in the way 16 in the rod 15 keeps the jaw 13 from rotating. The jaw moves up and down in a more or less fixed, non rotating position.
In order for the carrier to carry heavy loads and travel over rough terrain it is again imperative that the first pair of skis' attachment to the carrier be absolutely rigid. This is accomplished in all clamp embodiments by the shape of the jaws 11 and 13 and their relation to the clamp arms 12. The upper jaw 13 has a center portion with a through hole and two downwardly inclined outer portions. The through hole is sized to slidably engage the threaded rod 15. The lower jaws 11 each have a center portion with a through hole and two upwardly inclined outer portions. The through holes are sized to allow slidable engagement on the clamp arms 12. As jaws 11 and 13 are tightened by rotating spinner 14, the slope of the jaw's contact area forces the first pair of skis down and inward where the bottoms of the skis make contact with the surface of arms 12. As further tightened the ends of the clamp arms 12 pull against mainframe 19 forcing the skis further down and squeezing them against arms 12 making the entire assembly 10 very rigid. Because of the tapered shape of modern skis, the harder the first pair of skis are pulled, the more the clamp tightens.
FIG. 10 shows a similar embodiment of the ski clamping device. FIG. 10 is a four point device where the bar 60 that rides up and down clamp arms 12 simply keeps the upper jaws 13 from rotating rather than a key and way. Spinner 14 when rotated forces the bar 60 down and it in turn forces the jaws to tighten on the first pair of skis 1. The bar has a protruding flange housed in the bottom of spinner 14 to pull the bar up and loosen the clamp when the spinner is rotated in the opposite direction.
FIG. 10B is a three point device that works like the clamp of FIG. 7. It utilizes the key and way method of keeping the upper 13 jaw parallel to the lower jaws 11. Its clamping arms 12, however, remain below the top edges of the first pair of skis skis 1 allowing the upper jaw 13 to tightly grip the skis before it reaches the end of the threaded rod 15.
FIG. 2 and FIG. 5 show the rear view of an embodiment of the flanking ski support form 20 in the upright and holding position. The current embodiment is a shaped rigid rod. The flanking pair of skis rest in the saddle of the rod 20, FIG. 5. The pivot point of the rod, is offset so as to cause the weight of the supported skis to force the rod's arm down and to the out side of the carrier. There it contacts stop 26 and is restricted from traveling any further in its arch. The weight of the skis, coupled with the offset pivot point, allows the skis center of gravity to effectively lock the rod in position against 26 with no additional mechanisms. When rotated in the opposite direction or to the inside of the carrier, the rod will travel 100 plus degrees to its folded or prone position FIG. 2A.
FIG. 8 shows the front and rear view of an embodiment of the one piece horizontal support structure 40 resting on the mid section of the first pair of skis 1. The horizontal support structure 40 is held in position by the frictional contact between the U shape section of the bar and the skis. Rubber or like material should coat the bar to prevent marring and to increase the friction between the horizontal support structure and the skis. The flanking skis 2 rest on the horizontal rib and are secured against the upturned end 42 by means of a rubber type strap 44. Any like form could be employed for this horizontal support structure, as long as the skis remain secure in a position to maintain rigidity of the cradle area 5, FIG. 1A.
FIG. 9 discloses a one piece handle that can be used to enhance the pulling force exerted by the users hand. It simply slides over the tails of the first pair of skis. It comprises two sections. One section comprising 51 at one end and 52 at the other end is formed by a round rod of rigid material bent such that its end sections are, more or less, at right angles to the skis' edge 1. These ends are bent back over on themselves to form U shapes that are substantially perpendicular to the tops or flat side of the skis. These U shapes cradle the pair of skis in the bottom of the U shape. The loop shaped handle section has a straightened bottom section downwardly inclined. It is rigidly attached to a short section which is substantially perpendicular to the edge area of the first pair of skis. This short section is rigidly attached to the upper area of the rod between 51 and 52. As the handle is lifted and/or pulled forward, torque is transferred to the bar between 51 and 52. This causes section 51 to bear down on the top edge of the skis 1. At the same time the torque causes the section 52 to press up on the bottom edge of the skis 1. As this force is applied the angled inside walls of the U shaped end 51 forces the skis downward and inward while the angled inside walls of the U shaped section 52 force the skis upward and inward. This combination of forces squeezes the skis further together thus providing constantly self adjusting tension upon the skis. When the lifting and/or pulling force is removed the handle automatically loosens for easy removal.
FIG. 9A shows a slightly different embodiment of the handle of FIG. 9. The U shape ends 51 and 52 of rod section 55 are bisected where rod 55 is between the skis rather than along one side of the skis. The sides of the U shape force the bottoms of the skis against the rod 55 rather than against each other.
It is evident that the above described details are specific to the preferred embodiment of the invention. However, it should be understood that these should not be construed as limiting the scope of the invention. For example the horizontal support structure could be a solid rectangle with notches cut out to engage the skis and poles or the skis could be secured to the horizontal support structure with spring loaded clamps. The handle could fit between the first pair of skis' tails and grip the edges or a strap could encircle the tails to aid in pulling.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A ski transporting device which can carry three or more pair of skis, boots and poles. The device comprises three main components; 1, a two wheeled component detachably mounted to 2, a main or spine pair of skis and 3, a spanner support bar again detachably mounted to the spine pair of skis. This bar supports two or more additional pairs of skis which, in conjunction with the main pair, form a cradling space in which additional skis, ski poles and boots can stored and thus transported. An optional handle mounts on the opposite end of the main pair of skis to facilitate pulling the loaded device.
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BACKGROUND OF THE INVENTION
This invention relates to a ferritic stainless steel and its welded pipe used in the exhaust gas passage components of an automobile, typically in the exhaust manifold, catalytic converter case (cylindrical casing), front pipe and center pipe, and to automobile exhaust gas passage components utilizing the ferritic stainless steel and welded steel pipe.
The exhaust gas passage components of an automobile, such as the exhaust manifold, catalytic converter case, front pipe and center pipe, are required to be excellent in high-temperature oxidation resistance and high-temperature strength in the high-temperature region exceeding 700° C. As a material having such heat resistance, Patent Documents 1 and 2 teach ferritic stainless steels added with about 1 to 2 mass % of Cu. The Cu in the steel precipitates as Cu phase under heating to improve the high-temperature strength and thermal fatigue property of the steel.
Most of the aforesaid automobile exhaust gas passage components are produced by shaping welded steel pipes. Owing to the increasing number of units installed in the engine compartment in recent years, the amount of space available for installation of exhaust gas passage components has continued to decrease. This has led to many exhaust gas passage components being manufactured in complex shapes by special processing. The welded steel pipes used in exhaust gas passage components are therefore required to have even better formability than heretofore.
Regarding a technique for improving the formability of welded steel pipe made of ferritic stainless steel, Patent Document 3 teaches that trace addition of Al or Ti enhances the toughness and secondary workability of the weld. However, a study carried out by the inventors showed that trace addition of Al or Ti to ferritic stainless steel improved in high-temperature strength by inclusion of 1 to 2% Cu as mentioned above does not readily ensure sufficient toughness of a steel pipe produced by high-frequency welding. Moreover, sufficient toughness is even harder to achieve in a component such as a catalytic converter case because the component is manufactured by subjecting a steel pipe that has been TIG welded or laser welded to very severe compressive working (pressing or spinning). In other words, it was found that a welded steel pipe made of a ferritic stainless steel containing around 1 to 2% Cu cannot be adequately improved in toughness merely by trace addition of Al or Ti as taught by Patent Document 3.
In addition, the weld toughness of a high-frequency welded pipe is particularly easily affected by the pipe-making conditions determined by the amount of upset and heat input. In a ferritic stainless steel containing 1 to 2% Cu, the difficulty of consistently securing good toughness becomes even greater when the pipe-making conditions deviate from the optimum conditions.
Patent Document 1: WO 03/004714
Patent Document 2: JP 2006-117985A
Patent Document 3: JP 2005-264269A
SUMMARY OF THE INVENTION
An object of the present invention is to provide a ferritic stainless steel for automobile exhaust gas passage components which is a Cu-containing ferritic stainless steel excellent in high-temperature oxidation resistance and high-temperature strength that excels in the toughness of a weld formed during pipe-making (in this specification, “weld” is defined to include the welded metal and surrounding heat-affected metal) and that offers a wide range of freedom in selecting suitable pipe-making conditions especially when subjected to high-frequency welding pipe-making.
An in-depth study conducted by the inventors revealed that good toughness of the weld of ferritic stainless steel enhanced in high-temperature strength by Cu-phase precipitation can be effectively achieved by adding Ti and Al in combination and further strictly defining the Al content relative to the O (oxygen) content of the steel, thereby expanding the range of suitable pipe-making conditions in high-frequency welding pipe-making.
Specifically, the aforesaid object is achieved by a ferritic stainless steel for automobile exhaust gas passage components comprising, in mass percent, C: not more than 0.03%, Si: not more than 1%, Mn: not more than 1.5%, Ni: not more than 0.6%, Cr: 10-20%, Nb: not more than 0.5%, Ti: 0.05-0.3%, Al: more than 0.03% to 0.12%, Cu: more than 1% to 2%, V: not more than 0.2%, N: not more than 0.03%, B: 0.0005-0.02%, O: not more than 0.01%, optionally one or more of Mo, W, Zr and Co: total of not more than 4%, and the balance of Fe and unavoidable impurities, the composition satisfying Expressions (1) and (2)
Nb≧8(C+N) (1),
0.02≦Al−(54/48)O≦0.1 (2).
Each element symbol in Expressions (1) and (2) is replaced by a value representing the content of the element in mass percent.
Further, the present invention provides exhaust gas passage components of an automobile, typically in the exhaust manifold, catalytic converter, front pipe, center pipe, and other exhaust gas passage utilizing the welded steel pipe made of the aforesaid steel above.
The present invention enables actualization of welded ferritic stainless steel pipe that possesses the heat resistance (high-temperature oxidation resistance and high-temperature strength) required of automobile exhaust gas passage components and also exhibits excellent weld toughness. Moreover, the present invention provides greater freedom in selecting suitable pipe-making conditions at the time of manufacturing the welded pipe. Therefore, even in the case of high-frequency welding pipe-making conducted at a high line speed, for example, high-quality steel pipe with good weld toughness can be reliably manufactured.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a microphotograph showing an example of metal flow observed at a weld cross-section of a high-frequency welded pipe.
FIG. 2 is a graph showing how suitable pipe-making condition rate varied with effective Al content (Al−(54/48)O).
DESCRIPTION OF THE PREFERRED EMBODIMENT
The composition of the ferritic stainless steel will now be explained.
C and N are generally effective for improving creep strength and other high-temperature strength properties but degrade oxidation resistant property, workability, low-temperature toughness and weldability when contained in excess. In this invention, both C and N are limited to a content of not more than 0.03 mass %.
Si is effective for improving high-temperature oxidation resistance. Moreover, it bonds with atmospheric oxygen during welding to help keep oxygen from entering the steel. However, when contained in excess, it increases hardness and thus degrades workability and low-temperature toughness. In this invention, Si content is limited to not more than 1 mass % and can, for example, be limited to 0.1-0.6 mass %.
Mn improves high-temperature oxidation resistance, especially scale peeling resistance. And like Si, it also bonds with atmospheric oxygen during welding to help keep oxygen from entering the steel. However, Mn impairs workability and weldability when added in excess. Further, Mn is an austenite stabilizing element that when added in a large amount facilitates generation of martensite phase and thus causes a decline in workability and other properties. Mn content is therefore limited to not more than 1.5 mass %, preferably not more than 1.3 mass %. It can, for instance, be defined as 0.1 mass % to less than 1 mass %.
Ni is an austenite stabilizing element. Like Mn, it facilitates generation of martensite phase when added in excess and thus degrades workability and the like. A Ni content of up to 0.6 mass % is allowable.
Cr stabilizes ferrite phase and contributes to improvement of oxidation resistance, an important property of high-temperature steels. But an excessive Cr content makes the steel brittle and lowers its oxidation resistance. The Cr content is therefore defined as 10-20 mass %. The Cr content is preferably optimized for the use temperature of the steel. For example, when the temperature up to which good high-temperature oxidation resistance is required is up to 950° C., the Cr content is preferably 16 mass % or more, and when up to 900° C., is preferably 12-16 mass %.
Nb is a highly effective element for obtaining good high-temperature strength in the high-temperature region above 700° C. Solid solution strengthening is thought to make a major contribution in the composition of the present invention. Further, Nb has a C and N fixing action that works effectively to prevent a decline in toughness. In the present invention, effective improvement of high-temperature strength by Nb is ensured by incorporating the element in an amount satisfying Expression (1)
Nb≧8(C+N) (1).
However, excessive Nb addition lowers workability and low-temperature toughness, and increases susceptibility to hot weld cracking. It also reduces the suitable pipe-making condition rate discussed hereinafter. Nb content is therefore defined as not more than 0.5 mass %.
Ti fixes C and N and is generally known to be effective for improving formability and preventing toughness reduction. However the situation is different at a weld. Most N is fixed in the form of TiN but under exposure to high temperatures during welding, the TiN decomposes and the N thereof once enters solid solution in the high-temperature region. Although TiN is formed in the high-temperature region near the solidifying point of the steel, the very rapid cooling rate after welding makes it impossible to fix N thoroughly by Ti alone during the post-welding cooling period. As a result, N tends to be present in solid solution at the weld. Therefore, as will be gone into in detail later, this invention calls for addition of Al in combination with Ti. In order to thoroughly manifest the C and N fixing effect of Ti, the content of Ti must be made 0.05 mass % or greater. But excessive addition of Ti degrades surface property by causing generation of a large amount of TiN and also has an adverse effect on weldability and low-temperature toughness. Ti content is therefore defined as 0.05-0.3 mass %.
Al is an element commonly used as a deoxidizer and for improvement of high-temperature oxidation resistance. In this invention, however, it is particularly important as an element for fixing N at welds. As pointed out above, in the cooling phase after welding, it is impossible to fix N adequately at the weld by Ti alone. Unlike Ti, Al forms a nitride in the relatively low-temperature region below 1000° C. Addition of Al together with Ti therefore makes it possible to effectively fix N at the weld during post-welding cooling, thus mitigating toughness reduction at the weld. In addition, the fixing of N by Ti and Al mitigates strain aging and improves secondary workability at the weld.
At the weld, Al not only fixes N present in the steel but also acts to directly prevent entry of external N and/or O (oxygen) into the steel of the weld. This is significant because the atmosphere to which the molten metal is exposed during pipe-making (ordinarily shielded by N 2 , Ar or the like) entrains air, and when the amount entrained is great, N and O in the atmosphere tend to enter the steel from the weld to cause toughness reduction. However, in a ferritic stainless steel having an appropriate Al content, the Al in the steel acts to prevent entry of N and O from the atmosphere. Although the mechanism involved is not altogether clear, from the fact that analysis of the weld surface layer of a welded steel pipe made from the invention steel found concentration of Al, it is likely that Al 2 O 3 formed by Al in the steel during welding blocks dispersion of N and O into the interior.
An Al content exceeding 0.03 mass % must be established to fully bring out this effect of Al and thereby expand the range of freedom in selecting suitable pipe-making conditions in high-frequency welding pipe-making. However, when the Al content is excessive, oxides are abundantly formed during welding and operate disadvantageously as starting points for deformation cracking. The upper limit of Al content is therefore defined as 0.12 mass %.
The Al content must be further regulated relative to the O (oxygen) content of the steel so as to satisfy Expression (2)
0.02≦Al−(54/48)O≦0.1 (2).
As demonstrated by the Examples set out later, the freedom in selecting suitable pipe-making conditions in high-frequency welding pipe-making is markedly improved in the range of Al content satisfying Expression (2). The amount of Al represented by “Al−(54/48)O” is the Al remaining at the weld (called “effective Al” herein) after subtracting the Al consumed to form Al 2 O 3 by reaction with O present in the steel. It is thought that when the amount of effective Al rises to and above 0.02 mass %, O contained in the atmosphere during welding and the effective Al promptly unite to effectively block dispersion of N and O present in the atmosphere into the interior, thereby markedly improving the freedom in selecting suitable pipe-making conditions in high-frequency welding pipe-making. However, when the amount of effective Al comes to exceed 0.1 mass %, the freedom in selecting suitable pipe-making conditions declines sharply. The reason for this is probably that excessive Al oxides are formed at the weld and become starting points for deformation cracking.
Cu is an important element for enhancing high-temperature strength. More specifically, the present invention utilizes the finely dispersed precipitation of the Cu phase (sometimes called the ε-Cu phase) to enhance strength particularly at 500-700° C. A Cu content exceeding 1 mass % is therefore required. However, since too large a Cu content degrades workability, low-temperature toughness and weldability, Cu content is limited to not more than 2 mass %.
V contributes to high-temperature strength improvement when added in combination with Nb and Cu. And when co-present with Nb, V improves workability, low-temperature toughness, resistance to grain boundary corrosion susceptibility, and toughness of weld heat affected regions. But since excessive addition degrades workability and low-temperature toughness, V content is made not more than 0.2 mass %. V content is preferably 0.01-0.2 mass %, more preferably 0.03-0.15 mass %.
B is effective for inhibiting secondary working brittleness. The mechanism involved is thought to be reduction of oxygen in solid solution at the grain boundaries and/or grain boundary strengthening. However, excessive B addition degrades productivity and weldability. In this invention, B content is defined as 0.0005-0.02 mass %.
As O (oxygen) adversely affects weld toughness, the amount present in the steel is preferably minimal. O content is also preferably kept as low as possible in order to maintain the effective Al mentioned earlier at the required level. O content must be kept to 0.01 mass % or less and also made to satisfy Expression (2) relative to Al content.
Mo, W, Zr and Co are effective for improving the high-temperature strength of the ferritic stainless steel having the composition defined by the present invention. One or more thereof can be added as required. Owing to their embrittling effect on the steel when added in a large amount, however, the content of these elements, when added, is made not more than 4 mass % in total. Addition to a total content of 0.5-4 mass % affords optimum effect.
The ferritic stainless steel of the foregoing composition can be produced by the melting method using a steelmaking process for ordinary stainless steel and thereafter be formed into annealed steel sheet of around 1-2.5 mm thickness by, for example, a process of “hot rolling→annealing→pickling,” which may be followed by one or more cycles of a process of “cold rolling→annealing→pickling.” However, in order to achieve excellent high-temperature strength by Cu-phase precipitation, the average cooling rate from 900° C. to 400° C. in final annealing should preferably be controlled to 10-30° C./sec. By “final annealing” is meant the last annealing conducted in the steel sheet production stage and is, for instance, a heat treatment of holding the steel at a temperature of 950-1100° C. for a soaking time of 0-3 minutes.
The annealed sheet (pipe material) is roll-folded into a prescribed pipe shape and the so-formed butt joint of the material is welded to make a pipe and thus obtain a welded steel pipe. The welding can be done by TIG welding, laser welding, high-frequency welding or any of various known pipe welding methods. The obtained steel pipe is subjected to heat treatment and/or pickling as required, and then formed into an exhaust gas passage component.
EXAMPLES
The ferritic stainless steels of Table I were produced by the melting method and each was formed into two annealed steel sheets of different thickness, 2.0 mm and 1.5 mm, by the process of “hot rolling→annealing/pickling→cold rolling→final annealing/pickling.” The final annealing was conducted by holding at 1050° C. for 1 minute (soaking) and then cooling at an average cooling rate from 900° C. to 400° C. of 10-30° C./sec.
TABLE 1
Steel
Chemical Composition (Mass %)
[Nb]
[Al]
No.
C
Si
Mn
Ni
Cr
Nb
Ti
Al
Cu
V
N
B
O
Others
*1
*2
Invention
1
0.003
0.26
0.32
0.11
17.84
0.49
0.15
0.041
1.41
0.07
0.006
0.0020
0.0036
—
0.42
0.037
2
0.006
0.35
0.16
0.10
16.99
0.35
0.14
0.105
1.36
0.15
0.004
0.0005
0.0058
—
0.27
0.098
3
0.009
0.58
0.49
0.11
13.25
0.35
0.10
0.045
1.50
0.16
0.005
0.0011
0.0019
—
0.24
0.043
4
0.011
0.85
0.66
0.10
13.88
0.46
0.05
0.035
1.09
0.03
0.010
0.0030
0.0022
—
0.29
0.033
5
0.008
0.12
0.39
0.10
18.06
0.20
0.25
0.088
1.33
0.05
0.009
0.0022
0.0009
—
0.06
0.087
6
0.005
0.22
0.78
0.58
17.55
0.31
0.11
0.056
1.94
0.04
0.008
0.0012
0.0020
—
0.21
0.054
7
0.006
0.46
0.55
0.06
14.06
0.48
0.29
0.031
1.21
0.03
0.006
0.0026
0.0087
—
0.38
0.021
8
0.007
0.29
1.28
0.10
10.08
0.47
0.16
0.066
1.16
0.05
0.011
0.0005
0.0022
—
0.33
0.064
9
0.010
0.36
0.26
0.17
18.99
0.46
0.08
0.042
1.26
0.06
0.008
0.0016
0.0011
—
0.32
0.041
10
0.008
0.15
0.22
0.12
17.06
0.29
0.14
0.044
1.44
0.08
0.009
0.0015
0.0026
Mo: 2.26
0.15
0.041
11
0.006
0.14
0.19
0.09
18.12
0.21
0.12
0.038
1.26
0.06
0.008
0.0021
0.0029
W: 3.17
0.10
0.035
12
0.007
0.19
0.23
0.13
18.21
0.32
0.16
0.031
1.35
0.07
0.009
0.0019
0.0020
Co: 3.75
0.19
0.029
13
0.006
0.18
0.25
0.11
18.35
0.31
0.15
0.033
1.28
0.04
0.006
0.0017
0.0021
Zr: 1.49
0.21
0.031
14
0.006
0.57
0.22
0.10
11.22
0.29
0.10
0.040
1.44
0.05
0.007
0.0005
0.0031
Mo: 1.88, W:
0.19
0.037
2.08
Comparative
21
0.008
0.26
0.22
0.10
17.05
0.42
0.15
0.006
1.38
0.04
0.009
0.0005
0.0015
0.28
0.004
22
0.010
0.31
0.51
0.12
18.39
0.31
0.12
0.015
1.56
0.09
0.012
0.0039
0.0014
0.13
0.013
23
0.007
0.54
0.61
0.09
16.44
0.41
0.21
0.188
1.24
0.06
0.016
0.0041
0.0007
0.23
0.187
24
0.009
0.35
0.16
0.10
16.95
0.38
0.10
0.125
1.05
0.05
0.010
0.0010
0.0059
0.23
0.118
25
0.008
0.25
0.32
0.14
17.88
0.54
0.14
0.068
0.75
0.07
0.012
0.0008
0.0021
0.38
0.066
26
0.013
0.22
0.38
0.13
16.87
0.37
0.36
0.054
1.44
0.03
0.009
0.0012
0.0028
0.19
0.051
27
0.010
0.11
0.44
0.13
16.88
0.50
0.25
0.040
1.45
0.06
0.009
0.0025
0.0159
0.35
0.022
28
0.009
0.26
0.22
0.15
15.57
0.68
0.13
0.081
1.35
0.05
0.011
0.0014
0.0041
0.52
0.076
29
0.012
0.33
0.24
0.10
14.88
0.45
0.29
0.025
1.14
0.05
0.011
0.0015
0.0022
0.27
0.023
*1: [Nb] = Nb − 8(C + N),
*2: [Al] = Al − (54/48)O,
Underline: Outside invention range
Example 1
High-Frequency Welding Pipe-Making
High-frequency welding pipe-making was carried out under various conditions using the 2.0-mm steel sheet materials. The welded steel pipes manufactured had an outside diameter of 38.1 mm and a wall thickness of 2.0 mm.
<Suitable Pipe-Making Condition Rate>
The “suitable pipe-making condition rates (%)” of the obtained steel pipes were determined by the following method.
In the high-frequency welding pipe-making, the upset amount and heat input conditions that resulted in a metal flow angle of 45° were defined as the “optimum conditions” for the type of steel concerned. In the structure etched of the weld cross-section where a metal flow curve like that shown FIG 1 ( a ) appears, the angle between a line drawn to lie ¼ the wall thickness inward from the steel pipe outer surface (called the “reference line”) and the metal flow curve is defined as θ (see FIG. 1( b )) and the maximum value of θ in the steel pipe is defined as the metal flow angle of the steel pipe. In other words, the metal flow angle is measured by selecting from among the various metal flow curves the metal flow curve that makes the largest angle θ with the reference line. By “upset amount” is meant the butting amount of the sheet edges together during pipe welding. As a welding term, it is synonymous with “upset force.” By “heat input” is meant the electrical power of the high-frequency welding (=current×voltage).
High-frequency welding pipe-making was carried out using each type of steel sheet under 15 sets of welding conditions by varying “upset amount” among 3 levels (−30%, 0%, +30%) and “heat input” among 5 levels (−40%, −20%, 0%, +20%, +40%), where the two 0% values represent the foregoing “optimum conditions” as the standard. A pipe measuring about 1000 mm in length was cut from the steel pipe obtained under the each set of welding conditions, immersed for 15 minutes in a tank of 5° C. water, and then immediately subjected to a flattening test in accordance with JIS G3459, wherein the weld was placed at right angle to the direction of compression by flat jig plates and the distance H between the plates after compression was ⅓ the outside pipe diameter before compression. The percentage of the total of 15 sets of conditions for which no embrittlement was observed was calculated and defined as the “suitable pipe-making condition rate (%)” of the steel concerned.
A steel type whose suitable pipe-making condition rate calculated in this manner was 60% or greater was rated to be one enabling reliable manufacture of high-frequency welded steel pipe possessing the excellent weld toughness required by automobile exhaust gas passage components irrespective of the season of the year (temperature).
<Weld Transition Temperature>
A test specimen including the weld was cut from the high-frequency welded steel pipe made from each steel type under the “optimum conditions.” The transition temperature of the specimen was determined by conducting an impact test with the specimen set in a Charpy impact tester so that the hammer struck on the weld. A steel whose weld transition temperature was 0° C. or lower was rated “good.”
Example 2
Laser Welding Pipe-Making
Laser welding pipe-making was carried using the 1.5-mm steel sheet materials. The welded steel pipes manufactured had an outside diameter of 65 mm and a wall thickness of 1.5 mm. The welding conditions were such that the width of the rear bead of the weld was about the same as the wall thickness (in the range of 1.5-2.0 mm).
<Weld Transition Temperature>
A test specimen including the weld was cut from each welded steel pipe and the transition temperature was determined by conducting an impact test by the method explained above. A steel whose weld transition temperature was 0° C. or lower was rated “good”.
Example 3
High-Temperature Strength Measurement
The 2.0-mm steel sheet materials made from the steels of Table 1 were subjected to high-temperature tensile testing. A 0.2% yield strength at 900° C. of 17 MPa or greater was rated G (good) and one of less than 17 MPa was rated P (Poor).
The results obtained are shown in Table 2, while FIG. 2 shows how suitable pipe-making condition rate varied with effective Al content (Al−(54/48)O) in the invention steels and comparative steels Nos. 21-24.
TABLE 2
High-frequency
pipe-making
Suitable
Laser
pipe-making
Weld
pipe-making
condition
transition
Weld transition
Steel
rate
temperature
temperature
High-temperature
No.
(%)
(° C.)
(° C.)
strength
Invention steels
1
87
0
0
G
2
67
−25
−25
G
3
87
−25
−25
G
4
80
0
−25
G
5
60
−25
−25
G
6
80
−25
−25
G
7
67
0
0
G
8
67
0
−25
G
9
73
0
0
G
10
87
0
0
G
11
80
0
0
G
12
73
0
0
G
13
80
0
0
G
14
87
0
0
G
Comparative steels
21
27
25
25
G
22
47
25
25
G
23
13
50
50
G
24
27
50
50
G
25
87
0
−25
P
26
80
25
50
G
27
47
25
50
G
28
67
0
0
G
29
40
25
25
G
Underline: Unacceptable
As seen in Table 2, the ferritic stainless steels whose compositions were within the range defined by the present invention (invention steels) all exhibited suitable pipe-making condition rates of 60% or greater in high-frequency welding pipe-making. They were excellent in the transition temperature and high-temperature strength of the welds, thus confirming their suitability for use in exhaust gas passage components that undergo harsh working during fabrication. Of particular note is that freedom in selecting suitable pipe-making conditions was markedly improved by optimizing the relationship between Al content and O (oxygen) content so as to satisfy Expression (2) (see FIG. 2 ).
In contrast, the comparative steels Nos. 21 and 22 were low in Al content, so that adequate effective Al content as defined by Expression (2) could not be achieved. This is thought to have made it impossible to thoroughly prevent entry of N and O from the air during welding, leading to the inferior suitable pipe-making condition rate and low-temperature toughness of the weld. To the contrary, the Al content of comparative steels Nos. 23 and 24 was too high, causing Al oxides to form abundantly at the weld. This is thought to account for the low toughness. No. 25 was poor in high-temperature strength owing to too low Cu content. No. 26 was poor in low-temperature toughness owing to excessive Ti content. Because of the excessive O (oxygen) content of the steel, No. 27 experienced declines in both low-temperature toughness of the weld and suitable pipe-making condition rate even though it satisfied Expression (2). The suitable pipe-making condition rate of No. 28 was low because of excessive Nb content. Although No. 29 satisfied Expression (2), its insufficient Al content made it inferior to the invention steels in suitable pipe-making condition rate and low-temperature toughness of the weld.
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A ferritic stainless steel for automobile exhaust gas passage components comprises, in mass percent, C: not more than 0.03%, Si: not more than 1%, Mn: not more than 1.5%, Ni: not more than 0.6%, Cr: 10-20%, Nb: not more than 0.5%, Ti: 0.05-0.3%, Al: more than 0.03% to 0.12%, Cu: more than 1% to 2%, V: not more than 0.2%, N: not more than 0.03%, B: 0.0005-0.02%, O: not more than 0.01%, and the balance of Fe and unavoidable impurities, whose composition satisfies the relationships Nb≧8 (C+N) and 0.02≦Al−(54/48))≦0.1. The steel enables fabrication of automobile exhaust gas passage components that are excellent in high-temperature strength and weld toughness, and offers a wide range of freedom in selecting suitable pipe-making conditions.
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FIELD OF INVENTION
The present invention relates to a scientific demonstrator, and more particularly to motorized simulator that typifies the theoretical structure of an atom of various modeled molecules by demonstrating the electron orbits while being deflected magnetically.
BACKGROUND OF THE INVENTION
In the 5th cent. B.C. the Greek philosophers Democritus and Leucippus proposed that matter was made up of tiny, indivisible particles in constant motion. Aristotle, however, did not accept the theory, and it was ignored for centuries. Modern atomic theory began with the publication in 1808 by John Dalton of his experimental conclusions that all atoms of an element have exactly the same size and weight, and that atoms of elements unite chemically in simple numerical ratios to form compounds. In 1911, Ernest Rutherford explained an atom's structure in terms of a positively charged nucleus surrounded by negatively charged electrons orbiting around it. In 1911, Niels Bohr used quantum theory to explain why electrons could remain in certain allowed orbits without radiating energy.
The atom may be considered as the smallest particle into which matter can be broken up by chemical means. Though atoms can be further broken up into electrons, protons, neutrons, etc., by methods of modern physics, they retain their individuality in chemical reactions and are used as fundamental units in the organization of theory and facts of chemistry.
According to Bohr, the atom is built up of two units--a positively charged nucleus and a number of negatively charged electrons. The nuclear positive charge is equal to the atomic number while the mass is equal to the atomic weight. The electrons have a negative unit charge and a negative mass (1/1840 of the lightest nucleus). The number of electrons is equal to the charge on the nucleus measured in electron units of electrical charge, thus making the atom as a whole electrically neutral. The atom is essentially hollow with its mass concentrated at the nucleus and a cloud of orbital electrons revolving around it at various distances. On the basis of chemical and spectroscopic evidence these electrons are classified into shells called the K, L, M, N, O, P, Q shells. The following table gives the arrangement of the electrons among the electron shells for the various atoms.
______________________________________Atomic Number of Element K L M N O P Q______________________________________1 Hydrogen 12 Helium 23 Lithium 2 14 Beryllium 2 25 Boron 2 36 Carbon 2 47 Nitrogen 2 58 Oxygen 2 69 Fluorine 2 710 Neon 2 811 Sodium 2 8 112 Magnesium 2 8 213 Aluminum 2 8 314 Silicon 2 8 415 Phosphorus 2 8 617 Chlorine 2 8 718 Argon 2 8 819 Potassium 2 8 8 120 Calcium 2 8 8 221 Scandium 2 8 9 222 Titanium 2 8 10 223 Vanadium 2 8 11 224 Chromium 2 8 12 225 Manganese 2 8 13 226 Iron 2 8 14 227 Cobalt 2 8 15 228 Nickel 2 8 16 229 Copper 2 8 18 230 Zinc 2 8 18 231 Gallium 2 8 18 332 Germanium 2 8 18 433 Arsenic 2 8 18 534 Selenium 2 8 18 635 Bromine 2 8 18 736 Krypton 2 8 18 837 Rubidium 2 8 18 8 138 Strontium 2 8 18 839 Yttrium 2 8 18 9 240 Zirconium 2 8 18 10 241 Niobium 2 8 18 12 142 Molybdenum 2 8 18 13 143 Masurium 2 8 18 13 244 Ruthenium 2 8 18 15 145 Rhodium 2 8 18 16 146 Palladium 2 8 18 1847 Silver 2 8 18 18 148 Cadmium 2 8 18 18 249 Indium 2 8 18 18 350 Tin 2 8 18 18 451 Antimony 2 8 18 18 552 Tellurium 2 8 18 18 653 Iodine 2 8 18 18 754 Xenon 2 8 18 18 855 Cesium 2 8 18 18 8 156 Barium 2 8 18 18 8 257 Lanthenum 2 8 18 18 9 258-71 Cerium to Luthecium 2 8 18 19-32 9 272 Hafnium 2 8 18 32 10 273 Tantalum 2 8 18 32 11 274 Tungsten 2 8 18 32 12 275 Rhenium 2 8 18 32 13 276 Osmium 2 8 18 32 14 277 Iridium 2 8 18 32 15 278 Platinum 2 8 18 32 16 279 Gold 2 8 18 32 18 180 Mercury 2 8 18 32 18 281 Thallium 2 8 18 32 18 382 Lead 2 8 18 32 18 483 Bismuth 2 8 18 32 18 584 Polonium 2 8 18 32 18 685 -- 2 8 18 32 18 786 Radon 2 8 18 32 18 887 -- 2 8 18 32 18 8 188 Radium 2 8 18 32 18 8 289 Actinium 2 8 18 32 18 9 290 Thorium 2 8 18 32 18 10 291 Protactinium 2 8 18 32 18 11 292 Uranium 2 8 18 32 18 12 2______________________________________
The inert gases occupy a unique position in the table in that the outer shell of electrons contains two electrons in the case of helium and eight in the case of the other inert gases. An outer shell of eight electrons is therefore correlated with chemical inertness. This correlation can be further extended to the other groups of the periodic table where we find in the same group of the periodic table the same arrangement of the electrons in the outer shell of all members of the group. In this way the chemical characteristics of an atom are associated with the number of electrons in the outer shell.
U.S. Pat. No. 5,114,348, granted May 19, 1992, to S. Tzeng, discloses a tutorial device for observing the lunar phase. A base sheet is inscribed with a time scale, a ring of moon pictures and a ring of moon phases. Outer circles on the base sheet define the months and times of moonrise, moonset, and moonsharp.
U.S. Pat. No. 4,747,780, granted May 31, 1988, to S. Tzeng, discloses a multi-globe system including the sun, the earth, and the moon. It illustrates the revolution relation among the earth, the sun and the moon for teaching purposes.
U.S. Pat. No. 4,713,011, granted Dec. 15, 1987, to F. A. Alnafissa, teaches of an apparatus for simulating a large scale, rotating representation of the solar system inner planets and the sun. The apparatus is intended to be used as an educational tool in museums, in public displays and the like.
U.S. Pat. No. 3,835,554, granted Sep. 17, 1974, to J. B. Mast, discloses an improved space mechanical simulator having a sun model, an earth model, and a moon model mounted to demonstrate the movement of each relative to the other.
U.S. Pat. No. 3,750,308, granted Aug. 7, 1973, to D. E. Nelson, teaches of an educational demonstration model for demonstrating the principles of balance and the center of gravity, and the principles of the movement of the sun, the revolution of the earth around the sun, and the revolution of the moon around the earth.
Other apparatuses designed to demonstrate the various aspects of rotational electron movement were disclosed in U.S. Pat. No. 3,866,337 issued Feb. 18, 1975, to T. D. Burns, and in U.S. Pat. No. 3,706,141, issued Dec. 19, 1972, to T. F. McGraw, for example.
Several of the above referenced prior art patents disclose apparatuses that demonstrate the principles of planetary motion within our galaxy where the movement of the planets are virtually coplanar, while others demonstrate the theoretical structure of an atom.
SUMMARY OF THE INVENTION
The present invention finds particular application as an educational demonstrator that simulates the theoretical motion of the electron orbits of the atomic structure of various elements. For example, the K, L, M, N, shells of Germanium are 2, 8, 18, 4, respectively, and the shells of Magnesium are 2, 8, 2.
In the present embodiment, a clock motor rotating at a speed that ranges between 440 and 592 RPM, is used as a means of rotating the various electron models. However, in the preferred embodiment a synchronous constant speed motor is used to drive the modeled atoms. In an alternative embodiment, a hysteresis synchronous motor that is coupled to the drive shaft with an elastomeric belt, offers a system that is independent of changes in loading, as well as, a system that is impervious to changes in line frequency.
Mounted to the top of the motor drive shaft is a steel bar, upon which are mounted two magnetic structures. These two rotating magnets provide the magnetic coupling to drive the electron models.
Attached directly above the motor drive shaft is a non-magnetic support rod, preferably made of brass, that is in axial alignment with the principal drive shaft. Mounted on the support rod slightly above the area where each individual model is positioned, is a thick steel washer, upon which is mounted a fixed magnet that completes the magnetic path of the rotating magnetic field.
Each model is constructed of a thin flat steel washer that has a large diameter hole, typically 3/8" in diameter. Fixed to one side of the flat washer is a large flat magnet that has a 3/8" diameter hole through it. Mounted to the opposite side near the outer edges of the flat washer are two small magnets.
An array of thin wires that are attached to the Washer and project radially from the washer, support colored beads that represent the electrons. Each bead is colored with a highly visible iridescent paint to enhance the viewing when the model is being rotated. The inner most shell, K (consisting of two electrons), is colored in an iridescent orange, the next shell, L, is colored an iridescent red, the M shell, an iridescent green, then yellow, and so on.
In typical operation, the user inserts the model to be viewed into the lower position of the support shaft, then energizes the electric motor. The rotation of the drive shaft subsequently drives the magnetic impeller that is attached to the end of the drive shaft, causing a rotating magnetic field. Intermediate the rotating fixed magnet and the rotating magnets is the modeled atom structure. The rotating magnetic field is coupled into the magnets mounted to the atomic model, causing it to rotate in a wobbling manner of precession, perturbating freely, giving the illusion of the multiple orbital paths taken by each electron in their respective shell.
A black shrouded backdrop enhances the viewing contrast.
It is an object of this invention to provide for an educational demonstrator that simulates the electron orbits for various elements, showing their atomic structure.
It is another object of this invention to provide for an educational demonstrator that creates orbital electron paths that appear elliptical in a random distribution.
It is still another object of this invention to provide for an educational demonstrator that illustrates the relation between the various electron shells, as the electron rotate about its central nucleus.
Yet, it is another object of this invention to provide for an educational demonstrator that is driven by a synchronous motor to drive the simulation system.
It is a final object of this invention to provide for an educational demonstrator that magnetically couples the drive through the model to a fixed magnetic structure, thereby causing a rotating magnetic field, whereby the model rotates in a perturbationally random-like manner, simulating the theoretical electron orbital paths.
These and other advantages of the present invention will become more apparent to those skilled in the art upon reading the following detailed description when applied in conjunction with the drawings where it is shown and described illustratively the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the following drawings attached herein.
FIG. 1 is the top elevation of a theoretical model of the Germanium atom, where the shells are 2, 8, 18, 4, representing the K, L, M, N shells. The atomic structure shown is a typical arrangement for other modeled atoms.
FIG. 2 is the side elevation of a theoretical model of a typical Germanium atom.
FIG. 3 is a perspective view of the motorized educational demonstrator that simulates the theoretical electron orbits of various atomic structures by magnetically driving the modeled atoms.
FIG. 4 is a side elevation of the motorized educational demonstrator that simulates the theoretical electron orbits of various atomic structures by magnetically driving the modeled atoms.
FIG. 5 is a front elevation of the motorized educational demonstrator without the theoretical atomic structured model mounted.
FIG. 6 is a front elevation of the motorized educational demonstrator with the theoretical atomic structured model mounted, while being stationary.
FIG. 7 is a front elevation of the motorized educational demonstrator with the theoretical atomic structured model mounted, rotating, while being magnetically driven.
FIG. 8 is a top elevation of the motorized educational demonstrator with the theoretical atomic structured model mounted, rotating, while being magnetically driven.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more specifically to the drawings, the model of a typical theoretical atom is shown in FIGS. 1 and 2. The typical theoretical atom illustrated, 10, is an atom of Germanium, where the K, L, M, N shells are 2, 8, 18 and 4, respectively.
The Germanium model 10 is constructed of a thin flat steel washer 12 that has a large diameter hole, typically 3/8" in diameter. Affixed to one side of flat washer 12 is a large flat magnet 14 that has a 3/8" diameter hole through it. Mounted to the opposite side near the outer edges of the flat washer are two small magnets 16 and 18.
An array of thin wires 20 are attached to the washer and project radially from the washer. These wires support colored beads that represent the various electrons 22. Each bead is colored with a highly visible iridescent paint to enhance the viewing when the model is being rotated. The inner most shell 24, K (consisting of two electrons), is colored in an iridescent orange, the next shell 26, L, is colored an iridescent red, the M shell 28, an iridescent green, then iridescent yellow, 30, and so on.
Turning now to FIG. 4, and FIG. 5, which are a side elevational view and a from view respectively, of the educational demonstrator without the model of the atom inserted. A synchronous motor 32, rotating at a constant speed that ranges between 440 and 592 RPM, is used as a means of rotating the various individual electron models. If a greater speed accuracy is needed, a hysteresis synchronous constant speed motor can be used as an alternative embodiment. In still another embodiment, a hysteresis synchronous motor that is coupled to the drive shaft with an elastomeric belt, offers a system that is independent of changes in loading, as well as, a system that is impervious to changes in line frequency.
Mounted to the top of the motor drive shaft 40 is a steel bar 34, upon which are mounted two magnetic structures, 36 and 38. These two rotating magnets provide the magnetic coupling to rotate and drive the electron models.
Attached directly above the motor drive shaft 40 is a non-magnetic support rod 42, preferably made of brass, that is in axial alignment with the principal drive shaft 40. Mounted on the support rod 42 slightly above the area where each individual model is positioned, is a thick steel washer 44, upon which is mounted a fixed magnet 46, which completes the magnetic path of the rotating magnetic field. Another fixed magnet 50, when mounted centrally on the bottom of steel washer 44, as shown in FIG. 5, FIG. 6 and FIG. 7, allows the plane of the model to rotate about the rod while its peripheral edge fluctuates vertically. Whereas, when fixed magnet 50 is mounted off-center on the lower surface of steel washer 44, as in FIG. 3 and FIG. 4, rotation of the model provides multiple stationary orbits around a single axle, the support rod.
Found near the bottom of support rod 42 is a hub 48, comprised of two radially extending regions forming an annular concavity to that support and guide the model as it rotates, allowing the model to perturbate freely as shown in FIG. 3. Then in FIG. 6, the model of the atom 10 is shown mounted in position, but without the motor being energized.
In typical operation, the user inserts the model to be viewed 10 into the lower position of the support shaft hub 48, then energizes the electric motor 32. The rotation of the motor drive shaft 40 subsequently drives the magnetic impeller, comprised of rotating steel bar 34 and cylindrical magnets 36 and 38, that is attached to the end of the drive shaft, causing the magnetic field to rotate. Intermediate the rotating fixed magnet and the rotating magnets is the modeled atomic structure 10. The rotating magnetic field is coupled into the magnets mounted to the atom model, causing it to rotate in a wobbling manner of precession, perturbating freely, giving the illusion of the multiple orbital paths taken by each electron in their respective shell.
FIGS. 7 and 8 best shows the elliptical orbits that are taken when the motor is energized and the model 10 is being rotated within the magnetic field and centralized about hub 48. Each and every modeled atom produces the perturbating elliptical orbital paths that are taken by the various electrons within their respective shells.
As seen in FIG. 7, the device is secured on a base 54, with a floor 54a and top frame 54b which are interconnected by wall or backdrop 52. The black shrouded backdrop 52 enhances the viewing contrast of the iridescent colored rotating beads, thereby simulating the apparent paths taken by the electrons in orbit.
The polarity and positioning of each magnet is critical for the optimum performance. The polarity of fixed magnet 46 is such that "S" is located on the upper side of the magnet. It in turn coacts with magnet 14, whose upper side is "S," to act as an anti-gravitational device for the model that is inserted into position. Magnets 16 and 18, are repelled by magnets 36 and 38, so that as magnets 36 and 38 rotate, act to repel magnets 16 and 18, causing the model to be propelled in a circular path. Magnet 50, when positioned centrally on the support rod 42, further distorts the magnetic field as the model 10 rotates to cause the model to perturbate, thereby generating orbital paths in a random-like manner.
In another aspect of this invention, magnet 50 can be removed, and a model of the sun's planetary system inserted to simulate the motion of the planets about the sun.
It should be obvious to those skilled in the art that other substitutions in materials or alterations in dimensions can be made without departing from the spirit of the invention.
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A motorized scientific demonstrator that simulates the theoretical structure of an atom of various modeled molecules by demonstrating the rotational motion of the electron orbits by being deflected magnetically. Bohr's theoretical atom, which show the placement of the electrons in their respective K, L, M, N, O, P, Q shells, simulate the rotational movement of the electron orbits.
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BACKGROUND OF THE INVENTION
The present invention relates to thienopyridine derivatives which are useful as an immunoregulator and for the prevention and treatment of osteoporosis.
Thienopyridine derivatives represented by Formula (A), possess the 4-hydroxythieno[2,3-b]pyridin-6-one skeleton and are described in J. Chem. Res. (S), 214 (1985) and J. Chem. Res. (S), 122 (1986): ##STR2## wherein R.sup.∘ represents hydrogen or methyl and Y represents hydrogen or ethoxycarbonyl.
Furthermore, thienopyridine derivatives represented by Formula (B), possess the 7-hydroxythieno[3,2-b]-pyridin-5-one skeleton, and are described in J. Chem. Res. (S), 6 (1980) and J. Chem. Res. (S), 84 (1984): ##STR3## wherein R.sup.∘ represents hydrogen or methyl and Y represents hydrogen, ethoxycarbonyl, nitrile, acetyl or the like.
In compounds (A) and (B), their pharmacological acitivities are unknown.
SUMMARY OF THE INVENTION
The present invention relates to thienopyridine derivatives [hereinafter referred to as Compound (I)] represented by formula (I): ##STR4## wherein one of A and B represents -S-, and the other represent --CH═; R represents hydrogen or lower alkyl, and Z represents pyridyl; or a pharmaceutically acceptable salt thereof.
DETAILED DESCRIPTION OF THE INVENTION
In the definition of each group in formula (I), the lower alkyl means a straight or branched alkyl having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, etc.
The pharmaceutically acceptable salt of Compound (I) includes acid addition salts, metal salts, etc. The acid addition salt includes, for example, an inorganic acid salt such as hydrochloride, sulfate, phosphate, etc.; an organic acid salt such as acetate, maleate, fumarate, tartarate, citrate, etc. The metal salt includes for example, salts of alkali metal such as sodium, potassium, etc., salts of alkaline earth metal such as magnesium, calcium, etc.; aluminum salts, zinc salts and the like.
Next, a process for preparing Compound (I) is described.
In the process shown below, in cases where the defined group(s) change under the conditions or are inappropriate for the practice of the process, the process can be easily operated by applying thereto means conventionally used in organic synthetic chemistry, for example, protection of functional groups, removal of protective groups, etc.
Compound (I) may be obtained by reacting Compound (III) represented by formula (II): ##STR5## wherein L represents a leaving group; and A, B and R have the same significance as described above, with Compound (III) represented by formulas (III):
H.sub.2 N--X (III)
wherein X has the same significance as described above, preferably in the presence of a base.
Herein as the leaving group denoted by L, halogen such as chlorine, bromine, iodine, etc.; alkoxy such as methoxy, ethoxy, etc.; aryloxy such as phenoxy, etc.; alkanoyloxy such as propionyloxy, etc.; aroyloxy such as benzoyloxy, etc. are used.
As the base, alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate, etc.; alkali metal carbonates such as sodium carbonate, potassium carbonate, etc.; alkali metal hydrides such as sodium hydride, etc.; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, etc.; alkali metal salts such as butyl lithium, etc. are used.
As the solvent used in the reaction, any solvent may be usable, as long as it is inert to the reaction. For example, ethers such as tetrahydrofuran, dioxane, etc.; amides such as dimethylformamide, dimethylacetamide, etc.; ketones such as acetone, methyl ethyl ketone, etc.; alcohols such as methanol, ethanol, isopropyl alcohol, etc.; halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, etc.; esters such as ethyl acetate, etc.; aromatic hydrocarbons such as benzene, toluene, xylene, etc.; dimethylsulfoxide and the like may be used singly or in combination.
The reaction is carried out at -30° to 200° C., preferably -10° to 100° C. and generally completed in 30 minutes to 20 hours.
The starting compound (II) can be synthesized by known methods [J. Chem. Res. (S), 6 (1980); ibid., 84 (1984); ibid., 214 (1985); J. Chem. Res. (M), 113 (1980); ibid., 771 (1984); ibid., 2501 (1985)] or by a modified method of these methods.
The desired product in the process described above can be isolated and purified by means of purification conventionally used in organic synthetic chemistry, for example, by filtration, extraction, washing, drying, concentration, recrystallization, various chromatographies, etc.
Where it is desired to obtain the salts of Compound (I), Compound (I) may be purified as it is in case that Compound (I) is obtained in the form of its salt. In case that Compound (I) is obtained in its free form, Compound (I) is dissolved or suspended in a appropriate solvent and an appropriate acid or base is added to the solution or suspension to form its salts.
Compound (I) and a pharmaceutically acceptable salt thereof may also be present int he form of addition products with water or various solvents. These addition products are also included in the present invention.
Furthermore Compound (I) includes all possible steric isomers and mixtures thereof.
Specific examples of Compound (I) obtained by the process described above are shown in Tables 1 and 2.
TABLE 1______________________________________ ##STR6##Compound No. R Z______________________________________1 H ##STR7##2 H ##STR8##3 (CH.sub.2).sub.3 CH.sub.3 ##STR9##4 (CH.sub.2).sub.3 CH.sub.3 ##STR10##______________________________________
TABLE 2______________________________________ ##STR11##Compound No. R Z______________________________________5 (CH.sub.2).sub.3 CH.sub.3 ##STR12##6 (CH.sub.2).sub.3 CH.sub.3 ##STR13##7 H ##STR14##8 H ##STR15##______________________________________
Next, the immunoregulating activity, activity of inhibiting bone absorption and acute toxicity of Compound (I) are described by referring to test examples.
TEST EXAMPLE 1 Plaque Forming Cell Assay
The method developed by Jerne [Science, 140, 405 (1963)] and Yamamoto, et al [Drugs. Exptl. Clin. res., 8, 5 (1982)] were modified for plaque forming cell assay.
That is, Balb/c strain male mice (age of 7 weeks, Charles River Japan Inc.) were sensitized with 1×10 8 sheep red blood cells (Bio Test Research Institute) and the spleen was extirpated on the sixth or seventh day. The cells obtained from the spleen were treated with ACT solution (Tris-ammonium chloride isotonic buffer) to remove red blood cells. The cells were washed three times with RPMI-1640 medium (Nissui Pharmaceutical Co. . The cells (1×10 7 ) were incubated in RPMI-1640 medium containing 10% calf fetal serum (Gibco Co.), 50 μg/ml streptomycin, 50 IU/ml of penicillin, 2-mercaptoethanol (5×10 -5 M), sheep red blood cells (5×10 6 cells) and a test compound dissolved in dimethyl sulfoxide supplied on a microculture plate (NUNC Co., 24 wells) in a carbon dioxide gas incubator (TABAI ESPEC CORP) at 37° C. for 5 days.
After completion of the incubation, the cells were transferred to a plastic test tube and centrifuged at 2000 rpm. After the supernatant was removed, the cells were resuspended in 1 ml of RPMI-1640 medium. The cell suspension was sealed in a Cunnigham chamber (Takahashi Giken Co.) together with sheep red blood cells and guinea pig complement (Cedarlane Research Institute) according to the method of Cunnigham [Immunology, 14, 599 (1968)] and incubated at 37° C. for 1 to 2 hours. Direct plaque forming cell (PFC) count was counted.
A rate of inhibiting antibody production by the test compound was determined by the following equation. ##EQU1## A : PFC count in the absence of test compound (dimethylsulfoxide alone) B : PFC count in the presence of test compound
The results are shown in Table 3.
TABLE 3______________________________________Compound Concentration Direct PFC Count InhibitionNo. (M) (mean ± S.E.M.) Rate (%)______________________________________Control 5023 ± 383 10.sup.-4 101 ± 76 98.0 10.sup.-5 59 ± 38 98.84 10.sup.-4 336 ± 124 93.3 10.sup.-5 395 ± 52 92.15 10.sup.-4 109 ± 77 97.8 10.sup.-5 227 ± 131 95.56 10.sup.-4 42 ± 29 99.2 10.sup.-5 59 ± 29 98.8______________________________________
Autoimmune diseases such as chronic articular rheumatism or the like are considered to result from tissue injury due to accentuation of B cells as the result of hypofunction of T cells. It is thus expected that Compound (I) would be effective against autoimmune disease by inhibiting antibody production.
TEST EXAMPLE 2 Activity of inhibiting bone absorption
A calvaria of a 5 to 6 day-old dd mouse was aseptically cut off, washed with Dulbecco's modified phosphate buffered saline not containing calcium and magnesium (manufactured by Gibco Oriental Co.) and separated along the sutura of its center. One half of the calvaria so separated was cultured in 1.5 ml of Dulbecco's modified Eagle medium (manufactured by Gibco Oriental Co.) containing 15% of thermally inactivated (at 56° C. for 20 minutes) horse serum and 2.5% of fetal calf serum. The test compound was dissolved in dimethyl sulfoxide, and 10 μl (final concentration: 1×10 -4 M or 1×10- 5 M) of the solution so prepared was added to the culture. Parathyroid hormone (human PTH 1-34, manufactured by Sigma Co.) was dissolved in 0.15 M sodium chloride solution (pH 3), and 3 μl (final concentration: 1×10 -8 M) of the solution so prepared was added to the culture. The cultivation was carried out for 96 hours at 37° C. in an atmosphere consisting of 95% of air and 5% of carbon dioxide. The culture medium was once replaced with a fresh one after 48 hours from the beginning of the cultivation. The concentration of dissolved calcium (i.e., absorption of bone) from the PTH-intensified bone was determined by measuring the quantity of calcium accumulated in the culture collected in 96 hours of cultivation, whereby the concentration of total calcium contained in the culture was measured with Calcium C-Test Wako (manufactured by Wako Pure Chemicals Co., Ltd.), and the inhibition rate was calculated therefrom in accordance with the equation set forth below. The results are shown in Table 4. ##EQU2## Cd : Total calcium concentration in the culture treated with both test compound and PTH
Cp : Total calcium concentration in the culture treated with PTH alone
Co Total calcium concentration in the culture treated with neither test compound nor PTH
TABLE 4______________________________________Compound Concentration Inhibition RateNo. (μM) (%)______________________________________1 100 -12 100 513 10 1414 10 585 10 536 10 387 10 328 10 18______________________________________
TEST EXAMPLE 3 Acute toxicity test
A test compound was orally administered to three dd-strain male mice weighting 20±1 g. The minimum lethal dose (MLD) was determined by observing the mortality for 7 days after the administration.
The results are shown in Table 5.
TABLE 5______________________________________Compound No. MLD (mg/kg)______________________________________4 >3007 >300______________________________________
Compound (I) or a pharmaceutically acceptable salt thereof may be used as it is, or in various pharmaceutical forms. The pharmaceutical composition of the present invention can be prepared by uniformly mixing an effective amount of Compound (I) or a pharmaceutically acceptable salt thereof as the active ingredient with pharmaceutically acceptable carriers. The pharmaceutical compositions are desirably in a single dose unit suited for oral or parenteral administration.
In preparing the composition suited for oral administration, any pharmaceutically acceptable carrier may be used. Liquid preparations suited for oral administration, for example, a suspension and a syrup can be prepared using water; sugars such as sucrose, sorbitol, fructose, etc.; glycols such as polyethylene glycol, propylene glycol, etc.; oils such as sesame oil, olive oil, soybean oil, etc.; antiseptics such as p-hydroxybenzoic acid ester, etc.; flavors such as strawberry flavor, pepper mint, etc. Further a capsule, a tablet, a powder and a granule can be prepared using an excipient such as lactose, glucose, sucrose, mannitol, etc.; a disintegrator such as starch, sodium alginate, etc.; a lubricant such as magnesium stearate, talc, etc.; a binder such as polyvinyl alcohol, hydroxypropyl cellulose, gelatin, etc.; a surfactant such as a fatty acid ester, etc.; a plasticizer such as glycerine, etc. A tablet and a capsule are most useful single dose unit for oral administration because their administration is easy.
Effective dose and number of administration of Compound (I) or a pharmaceutically acceptable salt thereof may vary depending upon modes of administration, age and body weight, conditions, etc. of a patient but it is generally preferred to administer Compound (I) in a dose of 1 to 1,000 mg/60 kg by dividing into one to four times.
The present invention is described by referring to Examples and Reference Examples below.
EXAMPLE 1 5 4,5-Dihydro-7-hydroxy-5-oxo-N-(3-pyridyl)thieno[3,2-b]-pyridine-6-carboxamide (Compound 1)
A mixture of 2.43 g (10.2 mmols) of ethyl 4,5-dihydro-7-hydroxy-5-oxothieno[3,2-b]pyridine-6-carboxylate [J. Chem. Res. (S), 6 (1980); J. Chem. Res. (M), 113 (1980)], 1.00 g (10.6 mmols) of 3-aminopyridine, 50 ml of xylene and 10 ml of dimethylformamide was heated at 140° C. for an hour. After completion of the reaction, insoluble matters were filtered and recrystallized from dimethylformamide to give 1.56 g (yield: 54%) of Compound 1.
Elemental analysis: C 13 H 9 N 3 O 3 S:
Calcd. (%): C 54.35, H 3.16, N 14.63
Found (%) : C 54.11, H 2.85, N 14.48
IR (KBr) cm -1 : 3450(br), 1638, 1594, 1547, 1480, 1408, 1364, 1264, 1228, 799, 761
NMR (CF 3 CO 2 D) δ(ppm): 9.79(1H, s), 8.81(1H, d, J=8.8Hz), 8.63(1H, d, J=5.1Hz), 8.15(lH, m), 8.10 (1H, d, J=5.4Hz), 7.28(1H, d, J=5.4Hz)
EXAMPLE 2 4,5-Dihydro-7-hydroxy-5-oxo-N-(4-pyridyl)thieno[3,2-b]-pyridine-6-carboxamide (Compound 2)
A mixture of 2.48 g (10.4 mmols) of ethyl 4,5-dihydro-7-hydroxy-5-oxothieno[3,2-b]pyridine-6-carboxylate [J. Chem. Res. (S), 6 (1980); J. Chem. Res. (M), 113 (1980)], 1.01 g (10.7 mmols) of 4-aminopyridine, 50 ml of xylene and 10 ml of dimethylformamide was heated at 140° C. for an hour. After completion of the reaction, insoluble matters were filtered and tritylated with dimethylformamide with heating to give 1.99 g (yield: 67%) of Compound 2.
Elemental analysis: C 13 H 9 N 3 O 3 S
Calcd. (%): C 54.35, H 3.16, N 14.63
Found (%): C 54.31, H 2.96, N 14.45
IR (KBr) cm -1 : 3440(br), 1662, 1632, 1575, 1536, 1498, 1411, 1370, 1212, 1006, 826, 751
NMR (CF 3 CO 2 D) δ(ppm): 8.64(2H, d, J=7.0Hz), 8.46 (2H, d, J=7.0Hz), 8.11(1H, d, J=5.4Hz), 7.27(1H, d, J=5.4Hz)
EXAMPLE 3 4-(n-Butyl)-4,5-dihydro-7-hydroxy-5-oxo-N-(4-pyridyl)thieno-[3,2-b]pyridine-6-carboxamide (Compound 3)
A solution of 1.18 g (4.00 mmols) of the Compound a obtained in Reference Example 1, 0.39 g (4.13 mmols) of 4-aminopyridine and 20 ml of toluene was heated to reflux for 2 hours. After cooling, the reaction mixture was poured into 1 N sodium hydroxide aqueous solution, and washed twice with chloroform. 2 N Hydrochloric acid aqueous solution was added to the aqueous layer and the precipitated white crystals were filtered and dried to give 0.73 g (yield: 53%) of Compound 3.
Melting point: 211.9-216.5° C.
MS (EI) m/e: 343 (M + )
IR (KBr) cm -1 : 3420(br), 1661, 1617, 1591, 1546, 1509, 1393, 1196, 796, 758
NMR (DMSO-d 6 ) δ(ppm) 13.59(1H, s), 8.79(2H, d, J=6.6Hz), 8.38(1H, d, J=5.1Hz), 8.21(2H, d, J=6.6Hz), 7.57(1H, d, J=5.1Hz), 4.24(2H, t, J=7.6Hz), 1.66(2H, m), 1.40(2H, m), 0.93(3H, t, J=7.1Hz)
EXAMPLE 4 4-(n-Butyl)-4,5-dihydro-7-hydroxy-5-oxo-N-(3-pyridyl)thieno-[3,2-b]pyridine-6-carboxamide (Compound 4)
Compound 4 was obtained (yield: 72%) in a manner similar to Example 3 except for using 3-aminopyridine in place of 4-aminopyridine.
Melting point 179.7°-182.6° C.
MS (EI) m/e: 343 (M + )
IR (KBr) cm -1 : 3388, 1627, 1540, 1390, 798, 770, 668
NMR (DMSO-d 6 ) δ(ppm): 13.03(1H, s), 9.20[lH, d, J=2.2Hz), 8.62(lH, d, J=4.4Hz), 8.57(lH, dd, J=2.2Hz, 8.5Hz), 8.34(lH, d, J=5.4Hz), 7.90(lH, dd, J=4.4Hz, 8.5Hz), 7.55(lH, d, J=5.4Hz), 4.24(2H, t, J=7.5Hz), 1.65(2H, m), 1.40(2H, m), 0.93(3H, t, J=7.3Hz)
EXAMPLE 5 7-(n-Butyl)-6,7-dihydro-4-hydroxy-6-oxo-N-(4-pyridyl)thieno-[2,3-b]pyridine-5-carboxamide (Compound 5)
Compound 5 was obtained (yield: 78%) in a manner similar to Example 3 except for using Compound b obtained in Reference Example 2 in place of Compound a.
Melting point: 131.6°-139.4° C.
MS (EI) m/e: 343 (M + )
IR (KBr) cm -1 : 2952, 1614, 1507, 1380, 1289, 1197, 834, 663
NMR (DMSO-d 6 ) δ(ppm): 13.34(lH, s), 8.78(2H, d, J=6.4Hz), 8.20(2H, d, J=6.4Hz), 7.48(lH, d, J=5.6Hz), 7.39(lH, d, J=5.6Hz), 4.13(2H, t, J=7.4Hz), 1.75(2H, m), 1.41(2H, m), 0.95(3H, t, J=7.3Hz)
EXAMPLE 6 7-(n-Butyl)-6,7-dihydro-4-hydroxy-6-oxo-N-(3-pyridyl)thieno-[2,3-b]pyridine-5-carboxamide (Compound 6)
Compound 6 was obtained (yield: 76%) in a manner similar to Example 3 except for using Compound b obtained in Reference Example 2 in place of Compound a and using 3-aminopyridine in place of 4-aminopyridine.
Melting point: 158.0°-158.4° C.
MS (EI) m/e: 343 (M + )
IR (KBr) cm 1616, 1585, 1561, 1542, 1535, 1482, 752
NMR (DMSO-d 6 ) δ(ppm): 15.87(lH, s), 12.49(lH, s), 8.80(lH, d, J=2.1Hz), 8.37(lH, d, J=3.7Hz), 8.11 (1H, d, J=8.2Hz), 7.39-7.44(lH, m), 7.42(lH, d, J=5.5Hz), 7.35(lH, d, J=5.5Hz), 4.10(2H, t, J=7.5Hz), 1.74(2H, m), 1.40(2H, m), 0.95(3H, t, J=7.3Hz)
EXAMPLE 7 6,7-Dihydro-4-hydroxy-6-oxo-N-(4-pyridyl)thieno[2,3-b]-pyridine-5-carboxamide (Compound 7)
Compound 7 was obtained (yield: 58%) in a manner similar to Example 3 except for using ethyl 6,7-dihydro-4-hydroxy-6-oxothieno[2,3-b]pyridine-5-carboxylate [J. Chem. Res. (S), 214 (1985)]in place of Compound a.
Melting point: >300° C.
MS (EI) m/e. 287 (M + )
IR (KBr) cm -1 : 1660, 1633, 1573, 1544, 1487, 1426, 1356, 1009, 799, 560, 465
NMR (DMSO-d 6 ) δ(ppm): 15.58(1H, bs), 12.80-12.98(2H, m), 8.51(2H, d, J=6.4Hz), 7.64(2H, d, J=6.4Hz), 7.29(2H, s)
EXAMPLE 8 6,7-Dihydro-4-hydroxy-6-oxo-N-(3-pyridyl)thieno[2,3-b]-pyridine-5-carboxamide (Compound 8)
Compound 8 was obtained (yield: 75%) in a manner similar to Example 3 except for using ethyl 6,7-dihydro-4-hydroxy-6-oxothieno[2,3-b]pyridine-5-carboxylate [J. Chem. Res. (S), 214 (1985)] in place of Compound a, and using 3-aminopyridine in place of 4-aminopyridine.
Melting point: 294.8°-295.9° C.
MS (EI) m/e: 287 (M + )
IR (KBr) cm -1 : 1648, 1601, 1562, 1482, 1427, 1356, 1263, 801, 554, 472
NMR (DMSO-d 6 ) δ(ppm): 15.85(1H, s), 12.97(lH, s), 12.61(lH, s), 8.80(lH, d, J=2.5Hz), 8.37(lH, dd, J=1.1Hz, 4.7Hz), 8.04-8.13(lH, m), 7.42(lH, dd, J=8.2Hz, 4.5Hz), 7.29(lH, d, J=4.5Hz), 7.29(lH, dd, J=9.9Hz, 5.4Hz)
EXAMPLE 9 Tablet
A tablet having the following ingredients is prepared in a conventional manner.
______________________________________Compound 1 50 mgLactose 60 mgPotato starch 30 mgPolyvinyl alcohol 2 mgMagnesium stearate 1 mgTar pigment trace______________________________________
EXAMPLE 10 Syrup
A syrup preparation having the following ingredients is prepared in a conventional manner.
______________________________________Compound 2 50 mgRefined sugar 30 mgEthyl p-hydroxybenzoate 40 mgPropyl p-hydroxybenzoate 10 mgStrawberry flavor 0.1 cc______________________________________
Water is added until the total volume is 100 cc.
REFERENCE EXAMPLE 1 Ethyl 4-(n-butyl)-4,5-dihydro-7-hydroxy-5-oxothieno[3,2-b]-pyridine-6-carboxylate (Compound a)
A) To a solution of 15.7 g (0.100 mol) of methyl 3-aminothiophene-2-carboxylate and 15.2 g (0.110 mol) of potassium carbonate in 200 ml of dimethylformamide was added 34.1 ml (0.300 mol) of n-butyl iodide at 25° C. The mixture was stirred at 120° C. for 10 hours. After cooling, the solvent was evaporated under reduced pressure and 200 ml of ethyl acetate was added to the residue. An inorganic salt was removed by filtration. The filtrate was again concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluting solvent: ethyl acetate/n-hexane =1/9 v/v) to give 10.2 g (yield: 48%) of methyl 3-(n-butylaminothiophene-2-carboxylate (Compound a-1).
NMR (CDCl 3 ) δ(ppm): 7.35(lH, d, J=5.3Hz), 7.01-7.30 (1H, br), 6.98(1H, d, J=5.3Hz), 3.83(3H, s), 3.28 (2H, m), 1.21-1.88(4H, m), 0.95(3H, t, J=7.5Hz)
B) 10.0 g (46.9 mmols) of Compound a-1 was dissolved in a solvent mixture of 90 ml of 1,2-dichloroethane and 9 ml of 1,4-dioxane. 16.9 ml (0.141 mol) of trichloromethyl chloroformate was dropwise added to the solution at 25° C. The mixture was stirred at 75° C. for 7 hours. After cooling, 0.50 g of activated carbon was added to the reaction mixture followed by reflux for an hour in a nitrogen flow. After cooling, activated carbon was removed by filtration. The filtrate was concentrated under reduced pressure and 15 ml of ethyl acetate and 50 ml of n-hexane were added to the residue. The mixture was then stirred. The precipitated white crystals were filtered and dried to give 6.96 g (yield: of 4-(n-butyl)-5H-thieno[3,2-d]oxazine-5,7(4H)-dione (Compound a-2).
NMR (CDCl 3 ) δ(ppm): 7.95(1H, d, J=5.0Hz), 6.97(1H, d, J=5 0Hz), 4.01(2H, t, J=7.2Hz), 1.17-1.98(4H, m), 0.98(3H, t, J=7.4Hz)
C) Under ice cooling, 552 mg (24.0 mmols) of sodium hydride was added to 67.4 ml (0.444 mol) of ethyl malonate. The mixture was stirred at 25° C. for 30 minutes. To the solution mixture was added 5.00 g (22.2 mmols) of Compound a-2 and the mixture was stirred at 150° C. for an hour. After cooling, 300 ml of water was added to the reaction mixture. The mixture was washed twice with chloroform and 6 N hydrochloric acid aqueous solution was added to the aqueous layer. The precipitated crystals were filtered and dried to give 3.33 g (yield: 51%) of Compound a.
NMR (CDCl 3 ) δ(ppm): 7.69(1H, d, J=5.0Hz), 7.02(1H, d, J=5.0Hz), 4.18(2H, q, J=7.0Hz), 3.64(2H, t, J=7.5Hz), 1.08-1.76(4H, m), 1.22(3H, t, J=7.0Hz), 0.91(3H, t, J=6.1Hz)
REFERENCE EXAMPLE 2 Ethyl 7-(n-butyl)-6,7-dihydro-4-hydroxy-6-oxothieno[2,3-b]-pyridine-5-carboxylate (Compound b)
A) Methyl 2-(n-butyl)aminothiophene-3-carboxylate (Compound b-1) was obtained (yield: 23%) in a manner similar to Reference Example 1,A) step except for using methyl 2-amino-3-thiopenecarboxylate [Chem. Ber., 98, 3571 (1965)] in place of methyl 3-aminothiophene-2-carboxylate.
NMR (CDCl 3 ) δ(ppm): 7.08-7.38(1H, br), 7.03(lH, d, J=5.5Hz), 6.14(lH, d, J=5.5Hz), 3.83(3H, s), 3.23 (2H, q, J=6.2Hz), 1.22-1.90(4H, m), 0.96(3H, t, J=7.4Hz)
B) 7-(N-butyl)-6H-thieno[2,3-d]oxazine-4,6(7H)-dione (Compound b-2) was obtained (yield: 80%) in a manner similar to Reference Example 1,B) step except for using Compound b-1 in place of Compound a-1.
NMR (CDCl 3 ) δ(ppm): 7.59(1H, d, J=5.2Hz), 6.30(1H, d, J=5.2Hz), 3.97(2H, t, J=7.0Hz), 1.15-1.93(4H, m), 0.96(3H, t, J=7.4Hz)
C) Compound b was obtained (yield: 92%) in a manner similar to Reference Example 1,C) step except for using Compound b-2 in place of Compound a-2.
NMR (DMSO-d 6 ) δ(ppm): 7.34(1H, d, J=5.7Hz), 7.29(1H, d, J=5.7Hz), 4.32(2H, q, J=7.0Hz), 3.97(2H, t, J=7.3Hz), 1.60-1.71(2H, m), 1.30(3H, t, J=7.1Hz), 1.26-1.40(2H, m), 0.92(3H, t, J=7.3Hz)
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Disclosed is a thienopyridine derivative represented by formula (I): ##STR1## wherein one of A and B represents --S-- and the other represents --CH═; R represents hydrogen or lower alkyl, and Z represents pyridyl; or a pharmaceutically acceptable salt thereof.
The thienopyridine derivative is useful as an immunoregulator and for the prevention and treatment of osteoporosis.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a computer, and more particularly, to a computer with a removable add-on card fixing mechanism.
2. Description of the Prior Art
Computers are indispensable electronic products in modern life and are very popular with consumers. In order to make computers more useful and fulfill the various requirements of consumers, manufacturers have developed many different kinds of function-adding add-on cards. These add-on cards electrically connect to a computer through standardized slots on the computer motherboard and extend the function and capability of the computer. As new technologies are developed day-by-day and the requirements of consumers increase just as rapidly, computers are becoming lighter, thinner, and smaller. This means that computer designers and users must install more and more add-on cards into smaller computers. Add-on cards come in many different standards and sizes. If these add-on cards are installed vertically inside the computer, perpendicular to the motherboard, the size of the computer will be larger than if the add-on cards are installed in a horizontal manner, parallel to the motherboard. So to minimize the overall size and bulkiness of the computer many designers choose to do the latter.
Please refer to FIG. 1 . FIG. 1 is a perspective view of a prior art computer 10 . The computer 10 comprises a chassis 12 , a motherboard 14 , a processor 16 , a power supply 18 , and a riser card 20 . The motherboard 14 is fixed on the chassis 12 . The processor 16 is fixed on the motherboard 14 for controlling the operations of the computer 10 . The power supply 18 is fixed on the chassis 12 for providing electrical power to the computer 10 . The riser card 20 is vertically installed on and electrically connected to the motherboard 14 . The riser card 20 comprises at least a slot 24 for receiving an add-on card 22 so that the add-on card 22 can electrically connect to the motherboard 14 through the riser card 20 . The add-on card 22 is a network card, a video card, a RAID card, or any other type of function-adding card.
In order to accommodate flat shaped computer cases, the computer 10 shown in FIG. 1 uses the riser card 20 as an interface between the motherboard 14 and the add-on card 22 . The add-on card 22 is horizontally inserted into the slot 24 of the riser card 20 so that the add-on card 22 can electrically connect to the motherboard 14 through the riser card 20 . Although this assembly method can decrease the overall height of the computer 10 , it is inconvenient for operating staff or users to assemble. The computer 10 further comprises other electronic components installed on the motherboard 14 . Operating staff or users must exert a horizontal force directly on to the add-on card 22 each time it is inserted into or removed from the slot 24 of the riser card 20 . As it is easy to accidentally touch the electronic components on the motherboard 14 or on the add-on card 22 when inserting or removing the add-on card 22 electronic components are easily damaged.
SUMMARY OF INVENTION
It is therefore a primary objective of the claimed invention to provide a computer with a removable add-on card fixing mechanism, so as to solve the above mentioned problems.
The claimed invention, briefly summarized, discloses a computer. The computer comprises a chassis, a motherboard, at least a first coupler, and a fixing mechanism. The motherboard fixed on the chassis has a connecting port installed at one side of the motherboard along a first direction. The first coupler is formed on the chassis. The fixing mechanism comprises a housing, a first slot, at least a second slot, an active shaft and at least a second coupler. The housing is disposed along the first direction. The first slot is installed at a first side of the housing along the first direction and detachably connected to the connecting port. The second slot is installed at the first side of the housing along the first direction. The second slot is electrically connected to the first slot for electrically connecting an add-on card with the fixing mechanism. The active shaft is installed at a second side of the housing along the first direction. The active shaft has at least one supporting rod fixed at one end of the active shaft. The supporting rod is pivot connected to the housing so that the active shaft and the supporting rod can rotate about a rotation axis parallel to the first direction. The second coupler is formed at a bottom end of the supporting rod corresponding to a position of the first coupler for engaging with the first coupler.
It is an advantage of the claimed invention that the claimed invention computer comprises a detachable fixing mechanism. When users want to add an add-on card into the computer, users can first insert the add-on card into the second slot or the third slot on the riser card of the fixing mechanism. Users then attach the fixing mechanism to the computer chassis and rotate the active shaft about a rotation axis so as to move the fixing mechanism forward to connect the first slot with the connecting port. The claimed invention computer can be used to easily add an add-on card inside the computer. The assembly process is simple and time saving. Users do not need to exert force on the add-on card directly. The electronic components on the add-on card or on the motherboard are not touched when adding or detaching an add-on card and, therefore, the electronic components are not damaged.
These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a prior art computer.
FIG. 2 is a perspective view of a present invention computer.
FIG. 3 is an enlarged diagram (looking in a second side direction) of a first slot, a second slot and a third slot shown in FIG. 2 .
FIG. 4 is an enlarged diagram (looking in a first side direction) of the first slot, the second slot and the third slot shown in FIG. 2 .
FIG. 5 is a perspective view of the present invention computer in which the fixing mechanism shown in FIG. 2 is disposed on the chassis.
FIG. 6 is a side view (looking in the first direction) of the fixing mechanism and the motherboard in which the second couplers are engaged with the first couplers.
FIG. 7 is a side view (looking in the first direction) of the fixing mechanism and the motherboard in which the first slot of the fixing mechanism is connected onto the motherboard.
FIG. 8 is a side view (looking in the second side direction) of the lock and the power supply in which the lock is shown rotating from an unlocked position to a locked position.
FIG. 9 is a perspective view of the present invention computer in which the fixing mechanism is fixed on the computer.
DETAILED DESCRIPTION
Please refer to FIG. 2, FIG. 3 and FIG. 4 . FIG. 2 is a perspective view of a present invention computer 30 . FIG. 3 is an enlarged diagram (looking in a second side 46 direction) of a first slot 54 , a second slot 56 and a third slot 58 shown in FIG. 2 . FIG. 4 is an enlarged diagram (looking in a first side 44 direction) of the first slot 54 , the second slot 56 and the third slot 58 shown in FIG. 2 . The computer 30 comprises a chassis 32 , a motherboard 34 , and a fixing mechanism 50 . The motherboard 34 fixed on the chassis 32 has a connecting port 36 installed at one side of the motherboard 34 along a first direction 42 . Two first couplers 38 are formed on the chassis 32 . The computer 30 further comprises a processor 66 and a power supply 68 . The processor 66 is installed on the motherboard 34 for controlling the operations of the computer 30 . The power supply 68 is installed on the chassis 32 at the second side 46 of the housing 52 for providing electrical power to the computer 30 .
The fixing mechanism 50 of the present invention is detachable and is installed on the chassis 32 . The fixing mechanism 50 comprises a housing 52 , a riser card 53 , a first slot 54 , a second slot 56 , a third slot 58 , and an active shaft 60 . The active shaft 60 has two supporting rods 62 fixed at two ends of the active shaft 60 . The housing 52 is disposed on the chassis 32 along the first direction 42 . The riser card 53 is fixed under the housing 52 along the first direction 42 . The first slot 54 is installed at the first side 44 of the riser card 53 along the first direction 42 , and detachably connected to the connecting port 36 of the motherboard 34 . The second slot 56 and the third slot 58 are respectively installed at the first side 44 and the second side 46 of the riser card 53 along the first direction 42 . The second slot 56 and the third slot 58 are respectively connected to the first slot 54 for receiving the add-on card 48 so that the add-on card can electrically connect to the motherboard 34 through the first slot 54 . The add-on card 48 can be a network card, a video card, a RAID card, or any other type of add-on card. The active shaft 60 is installed at the second side 46 of the housing 52 along the first direction 42 . The supporting rods 62 are pivot connected to the housing 52 so that the active shaft 60 and the supporting rods 62 can rotate about a rotation axis 64 parallel to the first direction 42 . The second couplers 40 are formed at the bottom ends of the supporting rods 62 corresponding to positions of the first couplers 38 for engaging with the first couplers 38 . The housing 52 further comprises a lock 70 pivot connected to the second side 46 of the housing 52 . The lock 70 can rotate about a rotation axis 76 along an arrow direction 78 .
Please refer to FIG. 5 to FIG. 7 along with FIG. 2 . FIG. 5 is a perspective view of the present invention computer 30 in which the fixing mechanism 50 shown in FIG. 2 is disposed on the chassis 32 . FIG. 6 is a side view (looking in the first direction 42 ) of the fixing mechanism 50 and the motherboard 34 in which the second couplers 40 are engaged with the first couplers 38 . FIG. 7 is a side view (looking in the first direction 42 ) of the fixing mechanism 50 and the motherboard 34 in which the first slot 54 of the fixing mechanism 50 is inserted onto the motherboard 34 . When users want to add an add-on card 48 to the computer 30 , users can first insert the add-on card 48 into the second slot 56 or the third slot 58 on the riser card 53 of the fixing mechanism 50 . Users then connect the first slot 54 on the riser card 53 of the fixing mechanism 50 to the connecting port 36 of the motherboard 34 . When users want to attach the first slot 54 on the riser card 53 of the fixing mechanism 50 to the motherboard 34 , users can first dispose the fixing mechanism 50 on the chassis 32 so as to make the second couplers 40 engage with the first couplers 38 , as shown in FIG. 6 . Users then rotate the active shaft 60 about the rotation axis 64 so as to move the fixing mechanism 50 along the first side 44 direction to connect the first slot 54 on the riser card 53 with the connecting port 36 of the motherboard 34 , as shown in FIG. 7 . Therefore, the add-on card 48 inserted into the second slot 56 or the third slot 58 on the riser card 53 can electrically connect to the motherboard 34 through the first slot 54 on the riser card 53 . When users want to detach the fixing mechanism 50 from the motherboard 34 , users can rotate the active shaft 60 about the rotation axis 64 so as to move the fixing mechanism 50 along the second side 46 direction to separate the first slot 54 from the connecting port 36 . Users can then remove the fixing mechanism 50 from the computer 30 to add or exchange different add-on cards 48 .
Please refer to FIG. 8 and FIG. 9 . FIG. 8 is a side view (looking in the second side 46 direction) of the lock 70 and the power supply 68 in which the lock 70 rotates about the lock rotation axis 76 from an unlocked position 72 to a locked position 74 . FIG. 9 is a perspective view of the present invention computer 30 in which the fixing mechanism 50 is fixed on the computer 30 . As shown in FIG. 9, the lock 70 is disposed between the housing 52 and the power supply 68 . When the first slot 54 of the fixing mechanism 50 is connected to the connecting port 36 , the lock 70 can be rotated to the locked position 74 such that the lock 70 is between the housing 52 and a side wall 69 of the power supply 68 so that the side wall 69 of the power supply 68 can support the fixing mechanism 50 through the lock 70 . The lock 70 ensures that the first slot 54 can firmly connect to the connecting port 36 , as shown in FIG. 9 . Conversely, when users want to remove the fixing mechanism from the motherboard 34 , users can rotate the lock 70 to the unlocked position 72 so that the lock 70 is no longer positioned between the housing 52 and the side wall 69 of the power supply 68 . Users can then detach the fixing mechanism 50 from the motherboard 34 .
The lock 70 of the embodiment mentioned above can be positioned between the housing 52 and the side wall 69 of the power supply 68 , however, the present invention is not limited by this. Only if the side wall 69 can support the fixing mechanism 50 through the lock 70 is the side wall 69 to be included in the present invention.
Please continuously refer to FIG. 2 and FIG. 9 . In contrast to the prior art computer 10 , the present invention computer 30 comprises a detachable fixing mechanism 50 . When users want to add an add-on card 48 into the computer 30 , users can first insert the add-on card 48 into the second slot 56 or the third slot 58 on the riser card 53 of the fixing mechanism 50 . Users then attach the fixing mechanism 50 onto the motherboard 34 by connecting the first slot 54 of the fixing mechanism 50 to the connecting port 36 of the motherboard 34 . Finally, the lock 70 is rotated to the locked position 74 ensuring a firm connection between the first slot 54 and the connecting port 36 . Conversely, when users want to exchange an add-on card 48 , users can first rotate the lock 70 to the unlocked position 72 . Users then detach the fixing mechanism 50 from the motherboard 34 . Therefore, the present invention computer 30 makes it easier and quicker to add or replace add-on cards 48 inside the computer 30 . The assembly process is simple. Users do not need to exert force on the add-on card 48 directly. Electronic components are not touched when attaching or detaching the fixing mechanism 50 onto the motherboard 34 or when utilizing the fixing mechanism 50 and, therefore, the electronic components are not damaged.
Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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The computer includes a chassis, a motherboard, and an add-on card fixing mechanism. The motherboard is fastened to the chassis. The add-on card fixing mechanism is attached, yet removable from, the motherboard by first and second couplers located on the motherboard and add-on card fixing mechanism respectively. Add-on cards can be installed into the add-on card fixing mechanism. The add-on card fixing mechanism can then be attached to the motherboard. The add-on card fixing mechanism can then be actuated in such a way as to electrically and mechanically connect the add-on cards to the motherboard. Finally, the add-on card fixing mechanism can be actuated to remove the add-on cards and allow removal of the add-on card fixing mechanism from the motherboard.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to Gatling type guns, and more particularly to such a gun which can fire in both directions of rotation of its gun barrel rotor.
2. Prior Art
In U.S. Pat. No. 125,563 issued Apr. 9, 1872 to R. J. Gatling, there is shown the classic modern revolving battery gun. A stationary housing encloses and supports a rotor assembly which has a plurality of gun barrels, and a like plurality of gun bolts. Each bolt has its own firing pin and mainspring. As the rotor turns in an invariable direction, each bolt is traversed longitudinally by a stationary elliptical cam track in the housing. As the bolt is traversed forwardly, its firing pin is captured to the rear by a stationary cam track in the housing, compressing its mainspring until the bolt and the barrel reach the firing position, at which position the stationary cam track releases or sears the firing pin.
More modern Gatling type guns are shown by R. E. Chiabrandy in U.S. Pat. No. 3,380,341, issued Apr. 30, 1968; R. G. Kirkpatrick et al. in U.S. Pat. No. 3,611,871, issued Oct. 12, 1971, and R. M. Tan et al. in U.S. Pat. No. 3,738,221, issued June 12, 1973. In each of these guns the rotor turns in an invariable direction.
In the GAU-8 gun as carried by the A10 aircraft, the rotor turns in one direction to fire rounds, and turns in the opposite direction to clear unfired rounds back into the supply conveyor. A firing/safing cam which is adapted for use in the GAU-8 gun is shown by R. R. Snyder et al. in U.S. Ser. No. 058,359, filed July 17, 1979 now U.S. Pat. No. 4,274,325.
In U.S. Ser. No. 230,250 filed Feb. 2, 1981 D. P. Tassie shows a gun which may be driven and fired in both directions of rotation. Tassie provides a firing/safing cam having three dispositions: one permitting firing in one direction of rotation; another permitting firing in the other direction of rotation; and yet another safing against firing in either direction of rotation. These dispositions are achieved by means of a pivotal element which is controlled by two wedging elements.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved firing/safing cam for a Gatling type gun which may be driven and fired in both directions of rotation.
A feature of this invention is the provision of a Gatling type gun having a firing/safing cam assembly having three dispositions: one permitting firing in one direction of rotation; another permitting firing in the other direction of rotation; and yet another precluding firing in either direction of rotation of the rotor, all by means of two independently operated cam elements and a continuum element operated as a function of the respective dispositions of said cam elements.
DESCRIPTION OF THE DRAWINGS
These and other objects, features, and advantages of the invention will be apparent from the following specification thereof taken in conjunction with the accompanying drawing in which:
FIG. 1 is a perspective view of a gun embodying this invention;
FIG. 2 is a transverse cross-section of the gun of FIG. 1 showing the firing/safing cam assembly in it safe disposition;
FIG. 3 is a top view of the assembly of FIG. 2;
FIG. 4 is a detail of a FIG. 2 showing the firing/safing cam assembly in its counterclockwise firing disposition;
FIG. 5 is a top view of the assembly of FIG. 4;
FIG. 6 is a top view in cross-section of a detail of the assembly of FIG. 4; and
FIG. 7 is a top view in cross-section similar to FIG. 6 but showing the firing/safing cam assembly in its clockwise firing disposition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The gun shown in FIG. 1 is of the general type shown by R. G. Kirkpatrick et al. in U.S. Ser. No. 137,704, filed Apr. 7, 1980 now U.S. Pat. No. 4,342,253. It includes a dual feeder as shown by D. P. Tassie in U.S. Ser. No. 230,564 filed Feb. 2, 1981. The gun may be driven in both directions by suitable means, such as the hydraulic system utilized with the GAU-8/A gun in the A10 aircraft, or the system shown by G. W. Carrie in U.S. Pat. No. 4,046,056 issued Sept. 6, 1977.
Alternatively, the electrical system shown by J. A. Kleptz in U.S. Ser. No. 213,243 filed Dec. 14, 1980 may be utilized. Conventionally, such a drive is applied to a ring gear fixed to the gun rotor. In these systems the gun is driven in one direction to fire and in the other direction to clear. The changes in the control system to drive and fire in either direction are thought to be readily apparent.
These disclosures may be referred to for structure not shown or discussed herein.
The gun includes a housing 10 in which is journaled a rotor 12 having a plurality of gun barrels 14 and a like plurality of gun bolts 16, here shown as five in number.
Each gun bolt is disposed on tracks fixed to the rotor. Each bolt 16 has a roller which rides in a helical cam track in the housing 10, so that as the rotor rotates about the gun longitudinal axis, each gun bolt is traversed fore and aft on its tracks. Each gun bolt has a firing pin with a respective mainspring. Each firing pin has a respective cocking pin 22 standing up through a slot in the body of the gun bolt.
The safing and firing mechanism is fixed in the housing in a transversely extending slot therein.
The safing and firing mechanism includes a main frame 30 which is disposed in the slot of the housing and fixed by three bolts passing through bores in the frame and into tapped holes in the housing.
The main frame 30 extends through the slot and has a cam portion including a right cam surface 34, a left cam surface 36, and a central cutout 38 having a backwall 40, a right sidewall 42 and a left sidewall 44.
A right crank arm 46 is pivotally mounted to the main frame 30 by a pin 48 and has a tail portion 50 which is connected by a pin 52 to an actuator 54 of a solenoid 56. The actuator is biased by a helical compression spring 58. The right crank arm has a head portion 60 which has a cam surface 62. The spring of the solenoid normally biases the crank arm in the up disposition shown in FIG. 2 so that the head portion 60 is spaced up and away from the cam portion. When the solenoid 56 is energized the crank arm is forced into the down disposition shown in FIG. 4 so that the cam surface 62 is in annular alignment with the cam surface 34.
A left crank arm 64 is pivotally mounted to the main frame 30 by a pin 66 and has a tail portion 68 which is connected by a pin 70 to an actuator 72 of a solenoid 74. The actuator is biased by a helical compression spring 76. The left crank arm has a head portion 78 which has a cam surface 80. The spring of the solenoid normally biases the crank arm in the up position so that the head portion 78 is spaced up and away from the cam portion 36. When the solenoid is energized the crank arm is forced into the down disposition so that the cam surface 80 is in annular alignment with the cam surface 36.
A right lever 84 is pivotally mounted to the main frame 30 by a pin 86 and has right hand portion 88 with a right cam slot 90 and a left hand portion 92 with a left cam slot 94.
A left lever 96 is pivotally mounted to the main frame 30 by a pin 98 and has a left hand portion 100 with a left cam slot 102 and a right hand portion 104 with a right cam slot 106.
A safing gate 108 is disposed in part in a cutout 110 in the main frame 30. The gate has an upper portion having a right arm 112 which slides in a groove 114 and has a cam follower 116 which is disposed in the cam slot 94 of the right lever 84 and a left arm 118 which slides in a groove 120 and has a cam follower 122 which is disposed in the cam slot 106. The gate has a lower portion with a cam surface 123.
The right crank arm 46 has a cam driver 124 disposed in the cam slot 90 of the right lever 84, which serves to oscillate the right lever about its pivot 86 as the arm oscillates about its pivot 48.
The left crank arm 64 has a cam driver 126 disposed in the cam slot 102 of the left lever 96, which serves to oscillate the left lever about its pivot 98 as the arm oscillates about its pivot 66.
When the right solenoid 56 is de-energized, the spring 58 biases the crank arm clockwise with the cam surface 62 up and out of annular alignment with the cam surface 34. The cam driver 124 swings the right lever counterclockwise which carries with it the right hand portion 112 of the safing gate 108 so that the right hand portion of the cam surface 123 is spaced along the longitudinal axis of the gun away from the backwall 40 of the cutout 38 and is transversely aligned with the cam surface 34.
When the left solenoid 74 is de-energized, the spring 76 biases the crank arm counterclockwise with the cam surface 80 up and out of annular alignment with the cam surface 36. The cam driver 126 swings the left lever 96 clockwise which carries with it the left hand portion 118 of the safing gate 108 so that the left hand portion of the cam surface 123 is spaced along the longitudinal axis of the gun away from the backwall 40 of the cutout 38 and is transversely aligned with the cam surface 36.
Thus, when both solenoids 56 and 74 are de-energized, both cam surfaces 62 and 80 are up and away and the cam surface 123 is in transverse and annular alignment with the cam surfaces 34 and 36 and provides a continuum therebetween. This is the safe disposition of the assembly. When the rotor turns counterclockwise, each gun bolt, in sequence, is cammed progressively forward and its cocking pin 22 rides onto the cam surface 34 and progressively compresses the mainspring. However, the cocking pin continues to ride across on the cam surface 123 and then onto the cam surface 36. As the rotor continues counterclockwise, the gun bolt is cammed progressively rearward and its cocking pin 22 progressively releases the mainspring. When the cocking pin leaves the cam surface 36, the mainspring has been fully released, without firing. Similarly, when the rotor turns clockwise, the cocking pin 22 of each gun bolt rides onto the cam surface 36, progressively compresses its mainspring, rides across the cam surface 123 and then onto the cam surface 34 and progressively releases its mainspring, without firing.
When the right solenoid 56 is energized, and the left solenoid 74 is de-energized, the cam surface 62 is down and in annular alignment with the cam surface 34, while the cam surface 80 is up and away from the cam surface 36. Furthermore, the right hand portion of the cam surface 123 is adjacent the backwall 40, exposing the right wall 42 of the cutout 38, while the left hand portion of the cam surface 123 is spaced from the backwall 40 and is transverse and annular alignment with the cam surface 36. This is the counterclockwise firing disposition of the assembly. When the rotor turns counterclockwise, each gun bolt, in sequence, is cammed progressively forward and its cocking pin 22 rides onto the cam surface 34 and progressively compresses the mainspring. As the rotor continues counterclockwise, the cocking pin rides onto the cam surface 62 and further progressively compresses the mainspring until the cocking pin rides off the cam surface 62 and falls into the cutout 38, thereby firing the firing pin under the released compression of the mainspring. The cocking pin falls until it reaches the right hand portion of the cam surface 123 and then rides along the cam surface 123 until it rides off the left hand portion of the cam surface 123 onto the cam surface 36, during which travel it has withdrawn the firing pin and again progressively compresses the mainspring. As the rotor continues counterclockwise, the gun bolt is cammed progressively rearward and its cocking pin 22 progressively releases the mainspring. Should the gun have a reverse clearing mode of operation, then, while the gun is momentarily halted before turning in the reverse direction, the solenoid 56 is deenergized. This causes the cam surface 62 to move up and away, and the right hand portion of the cam surface 123 to be moved into transverse and annular alignment with the cam surface 34. The assembly is now in its safe disposition, as previously described. If a cocking pin 22 is lying on the cam surface 123 at this time, it will merely move along the axial direction of the gun with the right hand portion of the cam surface 123, compressing the mainspring. If a cocking pin 22 is lying on the cam surface 62 at this time, it will fall off the cam surface 62 onto the cam surface 34, which will not release the firing pin far enough for firing.
When the left solenoid 74 is energized, and the right solenoid 56 is de-energized, the situation is the mirror image of that previously described. This is the clockwise firing disposition of the assembly.
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A feature of this invention is the provision of a Gatling type gun having a firing/safing cam assembly having three dispositions: one permitting firing in one direction of rotation; another permitting firing in the other direction of rotation; and yet another precluding firing in either direction of rotation of the rotor, all by means of two independently operated cam elements and a continuum element operated as a function of the respective dispositions of said cam elements.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to valves and in particular to solenoid-operated cartridge valves.
2. Description of the Prior Art
In one form of fluid flow control valve, a poppet is seated against a valve seat to close the valve. The poppet is provided with a through bore which is selectively closed by a pilot valve. The poppet is spring-biased to the closed position with fluid pressure acting on opposite sides of the poppet so as to permit the spring biasing to maintain the poppet closed. When the pilot valve is raised from the valve seat, the fluid pressure behind the poppet is relieved to the through bore, thus permitting the fluid pressure acting upwardly on the poppet to move the poppet from the valve seat and thereby permit flow through the valve.
In one form, the pilot valve is operated by a suitable solenoid having a plunger connected to the pilot valve for selective positioning thereof in effecting the desired fluid flow control.
Such valves are provided in a wide range of sizes depending on the flow capacity desired.
It is further conventional to provide such valves in the form of cartridges, including both the valve and the solenoid operator in a single assembly which, illustratively, may be connected to suitable ports by a threaded adapter portion thereof.
SUMMARY OF THE INVENTION
The present invention comprehends an improved solenoid poppet valve structure providing improved performance and economy of manufacture.
The invention comprehends the provision of such a valve having an improved pilot valve guide arranged to utilize the single size pilot valve with any one set of a plurality of different size cooperating sets of valve seat members and poppets, each having the same pilot valve seat configuration.
In the illustrated embodiment, the pilot guide comprises any one of a plurality of pilot guides each having a different lateral extent outturned flange for permitting a single size valve pilot to be utilized with any one of the different size sets of seat members and poppets.
The invention comprehends the provision of such a valve structure wherein the slide portion of the pilot defines a flatted cross section to define flow passages extending longitudinally at the periphery of the slide portion.
In the illustrated embodiment, a pair of flats on diametrically opposite sides of the pilot slide portion is provided.
The invention further comprehends providing a T-slot in the solenoid plunger, with the valve pilot having a connecting head received in the T-slot.
In the illustrated embodiment, the T-slot extends fully diametrically across the plunger.
More specifically, the invention comprehends the provision in a solenoid valve structure having a plunger and a valve pilot for controlling the movement of a main valve poppet, of means in an end portion of the plunger defining a radially extending T-slot, the longitudinal portion of which opens through the end of the plunger, and means on the valve pilot defining a connecting head received in the slot, the T-slot extending fully transversely through the plunger, the longitudinal extent of the longitudinal portion of the T-slot being less than approximately one-half the longitudinal extent of the T-slot.
The connecting head has a transverse extent throughout less than that of the T-slot permitting ready fluid flow past the connecting head into the T-slot.
The pilot guide defines a surface adjacent the end portion of the plunger forming a fluid chamber opening to the longitudinal portion of the T-slot.
The invention further comprehends the provision of a solenoid valve structure having solenoid means defining a plunger chamber, a solenoid plunger reciprocally slidable in the chamber, and valve means connected to the plunger at one end of the plunger chamber defining a tapered surface narrowing to a transverse end surface, means on an adjacent end of the solenoid plunger defining a complementary tapered surface and transverse end surface, passage means in the solenoid plunger for conducting fluid from the portion of the chamber between the surfaces, and means for limiting the movement of the solenoid plunger toward the surface means at one end of the plunger chamber to prevent engagement of the transverse end surfaces and maintain a fluid transfer portion in the plunger chamber between the end surfaces at all times communicating with the passage means.
In the illustrated embodiment, the tapered surfaces are substantially frustoconical.
In the illustrated embodiment, the transverse end surfaces are substantially planar.
The movement limiting means in the illustrated embodiment comprises cooperating stop surfaces on the solenoid plunger and solenoid means at the wide end of the plunger chamber tapered surface.
The cartridge solenoid poppet valve structure of the present invention is extremely simple and economical of construction while yet providing the highly desirable features discussed above.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:
FIG. 1 is a perspective view of a cartridge valve embodying the invention;
FIG. 2 is an enlarged diametric section thereof;
FIG. 3 is a transverse section taken substantially along the line 3--3 of FIG. 2;
FIG. 4 is a transverse section taken substantially along the line 4--4 of FIG. 2;
FIG. 5 is a diametric section of a modified form of cartridge form embodying the invention having a pilot guide adapted for use with different size poppet and seat members; and
FIG. 6 is a diametric section of a cartridge valve generally similar to the cartridge valve of FIGS. 1-5, but arranged for normally open operation
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the illustrative embodiment of the invention as disclosed in the drawing, a cartridge solenoid poppet valve generally designated 10 includes an adapter 11 having a threaded portion 12 adapted to be threaded into a fluid port. The adapter includes a threaded end 13. A seat member 14 is provided with a threaded end 15 threaded to the adapter end 13 so as to be received within the fluid port.
A first sealing ring 16 is provided on the adapter and a second sealing ring 17 is provided on the seat member for sealing the valve assembly within the fluid port.
As shown in FIG. 2, a backup ring 18 may be associated with the sealing ring 17 in a suitable outwardly opening, annular recess 19 of the seat member.
The seat member is provided with a pair of diametrically opposite inlet openings 20 and 21, which open radially inwardly into a valve chamber 22 within the seat member. An outlet opening 23 opens axially from the valve chamber 22 and is normally closed by a valve member 24 seating on an annular seat 25 of the seat member at the inner end of the outlet port 23.
Thus, when installed in a suitable port member, fluid pressure between seals 16 and 17 is applied through the inlet ports 20 and 21 against the valve member 24. In the illustrated embodiment, valve member 24 comprises a poppet valve having a lower seating portion 26 engaging the valve seat 25 and provided with an axial bore 27 having an outer counterbore 28 receiving a check valve 29. The check valve prevents fluid pressure in the outlet port 23 from causing a reverse flow through the bore 27 into a pilot valve chamber 30 within the valve member 24.
Bore 27 is normally closed by a pilot valve 31 having a slide portion 32 slidably received in an upper cylindrical recess 33 of the valve member 24. The slide portion 32 is provided with a pair of diametrically opposite flats 34 for providing fluid communication between a transfer chamber 35 and the pilot valve chamber 30.
Slide portion 32 acts as a pilot guide and defines an upper end 36 abutting a lower end 37 of a solenoid plunger 38 in the normally closed arrangement of the valve. A helical coil spring 39 extends between the guide portion 32 and the seating portion 26 of valve member 24 to bias the poppet valve downwardly relative to the guide portion 32. As shown in FIG. 2, however, when plunger 38 is in the outermost position with portion 37 thereof abutting the inner end 36 of the pilot guide portion 34, the plunger urges both the pilot valve and the poppet valve 24 outwardly into the seated arrangements of FIG. 2.
In the normally closed arrangements of the solenoid valve 10, the plunger is biased outwardly by a helical coil spring 43 acting between an inner end portion 40 of the plunger and a plug 41. Spring 43 has a strength greater than spring 39 and, thus, overcomes the spring 39 to arrange the valve components in the normally closed position of FIG. 2.
As further illustrated in FIG. 2, valve member 24 is provided with a bleed passage 42 providing communication between the inlet 20 and the pilot valve chamber 30 at all times. Thus, in the normally closed position wherein the pilot valve 31 is closing the pilot opening 27, fluid pressure at the inlet openings 20 is transmitted through the bleed passage 42 into the pilot valve chamber 30 and acts to maintain the poppet valve member 24 in the closed position illustrated in FIG. 2, in cooperation with the springs 43 and 39.
Pilot valve 31 is moved from the seated position illustrated in FIG. 2 by suitable longitudinal movement of plunger 38 inwardly toward plug 41 under the control of a solenoid coil 44. In the illustrated embodiment, the coil 44 is carried in an annular bobbin 45 mounted within an open-sided, generally parallelepiped shaped, enclosing frame 46 having an inner end 47 and an opposite outer end 48. Frame end 47 is provided with an opening 47a inwardly through which plug 41 extends and frame end 48 is provided with an opening 48a outwardly through which plunger 38 extends. The frame is encapsulated in an outer housing 49 which may be formed of a suitable synthetic resin. The space within the frame surrounding the coil may be filled with a suitable synthetic resin, such as an epoxy resin.
A washer 50 is provided in the housing surrounding the upper end of plug 41, and is provided with an axially turned inner end portion 51 extending outwardly to the outer surface of the housing to be engaged by a nut 52 threaded to the distal threaded end 53 of the plug 41.
End 48 of the frame abuts the adapter 11 radially inwardly of the housing 49 and, thus, nut 52 acting through washer 50 and frame 46 effectively clamps the solenoid structure generally designated 53 to the adapter.
As further illustrated in FIG. 2, a slide tube 54 is secured to the plug 41 as by brazing 55 to extend inwardly of the bobbin 45 and includes a lower end portion 56 received in a suitable recess 57 in the adapter 11. Plunger 38 is reciprocably slidable in the tube 54 between the normally closed position of the valve illustrated in FIG. 2, and an open position of the valve wherein the plunger is raised into abutment with plug 41.
Upper end 36 of pilot valve 32 defines a cylindrical head received in a T section transverse slot 58 provided in the lower end of the plunger 38. The stem portion 59 of the slot is relatively short so as to provide high strength in the end portion 60 of plunger 38 confronting the transfer chamber 35.
A fluid flow passage 61 extends from the T-slot upwardly to a recess 62 receiving coil spring 43 and opening to the space 63 between the upper end 64 of plunger 40 and the lower end 65 of plug 41.
Illustrated in FIG. 2, surface 64 of the plunger is defined by a radially inner frustoconical portion 66 and a radially outer annular planar portion 67. Surface 65, in turn, is defined by a planar radially inner portion 68, a frustoconical midportion 69 and an annular planar outer portion 70.
The length of frustoconical surface portion 66 is made to be slightly less than the length of frustoconical surface portion 69 of plug 41 so that when the plunger is moved inwardly upon energization of the coil 44, surface 67 of the plunger abuts surface 70 of the plug, with the plunger remaining spaced from the planar surface 68 of the plug, thereby to avoid entrapment of fluid in the space 63 upon energization of the solenoid.
Fluid may flow freely from space 63 upon such energization of the solenoid downwardly through recess 62 and passage 61 into T-slot 58. End portion 36 of the pilot valve includes a cylindrical head portion 71 and a reduced diameter cylindrical stem portion 72 connected to the slidable guide portion 32 of the pilot valve. Stem portion 72 has clearance with the plunger portion 60 within the stem portion 59 of the T-slot so that fluid may flow freely downwardly past the stem portion 72 of the pilot valve end portion into the transfer chamber 35.
As indicated above, the slidable guide portion 32 of the pilot valve is provided with at least a pair of diametrically opposite flats 34 defining flow passages for permitting flow of the entrapped fluid outwardly therethrough into the pilot valve chamber 30 for delivery with the fluid flowing through the valve in the open condition of the valve.
As shown in FIG. 2, outer end surface 90 of the plunger is urged against an inner end surface 91 of guide portion 32 of the pilot valve. As shown, the axial length of head 71 and stem 72 of guide portion 36 is less than the spacing between surface 90 and the inner end 92 of T-slot 58 to provide clearance with the guide head 71 to permit fluid flow between flow passage 61 and T-slot 58 at all times.
By maintaining the plunger spaced from end surface 68 at all times, entrapment of fluid between the plunger and plug is effectively prevented. By providing the improved fluid flow passages, including the diametrically extending T-slot and the flats on the guide portion 32 of the pilot valve, improved free movement of the pilot valve is provided for improved functioning of the valve structure 10.
The solenoid valve 10 is adapted, as indicated above, to be mounted to a port, such as port 73 illustrated in FIG. 1, having a threaded opening 74 to which threaded portion 12 of the adapter 11 is threaded, with the seat member 14 disposed innermost within the port opening. As indicated above, sealing ring 16 seals the valve to the port about the opening 74 and the O-ring 17 seals the seat member to the port within the opening to provide a sealed fluid passage through the valve within the port.
As illustrated in FIG. 5, the invention further comprehends the provision of a modified form of poppet valve generally designated 110 similar to poppet valve 10 but wherein the pilot valve guide portion 132 is slidably received in a pilot guide 175 clamped between the seat member 114 and the adapter 111.
Thus, as more specifically illustrated in FIG. 5, pilot guide 175 includes a radially inner portion 176 slidably receiving the pilot valve guide portion 132, and an annular outturned portion 177 defining a radially and axially outwardly opening annular corner recess 178 seating against the inner end of the seat member 114 when the seat member is threaded fully into the adapter threaded end 113.
As shown in FIG. 5, the pilot valve spring 139 extends between the outturned portion 177 of the pilot guide and the outer end of the poppet valve member 124.
The pilot valve member is provided with a bleed passage 142 providing communication at all times between the inlet 120 and the pilot valve chamber 130.
The combination of the pilot guide 175, poppet valve member 124 and seat member 114 illustrated in FIG. 5 comprises one set of a plurality of different size cooperating sets of such adapters, poppet valve members and seat members each having the same pilot valve seat configuration so that the same pilot valve structure may be used with a line of valves differing only in the flow capacity provided by the different size poppet valves and seat members. Thus, the pilot guides may be adapted for such a wide range of valve capacities by varying the radial extent of the outturned portion 177 to mate with the selected seat member 114 and complementary valve member 124.
Other than for the use of the pilot guide 175 providing for adaption of the solenoid valve structure to a wide range of different size fluid control valves utilizing the same pilot valve configuration, poppet valve structure 110 is similar to poppet valve structure 10 and functions in a similar manner.
Referring now to the embodiments of FIG. 6, a poppet valve generally similar to poppet valve 10 but arranged to function in a normally open manner, is shown to comprise a poppet valve structure generally designated 210. The solenoid structure 253 is generally similar to solenoid structure 53 except that a threaded cap 252 is provided on the threaded end 279 of the plug 241 fitting to a projecting end 280 of the slide tube.
The plunger 240 is slidably received in the slide tube within the solenoid structure 253. The plunger defines an outer frustoconical end 281 having a planar distal end surface 282. A pilot housing 283 is retained coaxially within the outer end of the slide tube and defines a frustoconical recess 284 complementary to the frustoconical end 281 of the plunger.
The pilot housing further defines a through bore 285 opening outwardly into the pilot chamber 230.
Pilot valve 231 includes an inwardly projecting rod 286 which extends inwardly into abutment with the plunger surface 282, as shown in FIG. 5.
The pilot valve further defines an annular flange 287. A pilot valve biasing spring 239 is seated inwardly against flange 287 and outwardly against a spring retainer plate 288 clamped between the seat member 214 threaded to the adapter 211.
The pilot valve stem 272 extends outwardly through a suitable opening 289 in the spring retainer plate.
Spring 239 normally biases the pilot valve inwardly permitting fluid pressure from inlet openings 220 to urge the poppet valve 224 from the valve seat 225. However, when solenoid structure 253 is energized, the plunger 240 is urged outwardly moving the pilot valve rod 286 outwardly and thereby urging the pilot valve outwardly against the poppet valve 224 so as to move the poppet valve into seated relationship with valve seat 225, thereby closing the valve.
Thus, the normally open valve structure 210 is similar to the normally closed valve structure except for the rearrangement of the parts to provide the normally open functioning.
As discussed above, each of valve structures 110 and 210 is generally similar in structure and functioning to valve structure 10 and similar elements thereof are identified by similar reference numerals except for being 100 and 200 higher, respectively.
The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.
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A cartridge solenoid poppet valve (10) arranged to use a single size pilot valve (31) with any one of a set of a plurality of different size sets of valve seat members (14) and poppet valves (24). Pilot guides (175) are provided having different transverse extents to accommodate such different size valve members. The valve further includes a flatted pilot guide (32) defining flow passages communicated between a transfer chamber (35) and a pilot valve chamber (30) in which the pilot valve (31) is disposed. A T-slot (58) is provided in the solenoid plunger (38) extending fully diametrically thereacross and the pilot valve includes a T-shaped connecting head (71) received therein. The plunger (38) and plug (41) define cooperating stop surfaces (67,70) for maintaining a small spacing between the plunger and plug at all times.
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TECHNICAL FIELD
The present invention relates to a motor control device using an inverter or inverters, in particular, it relates to a motor control device which is suitable for the prevention of inertial rotation at a service interruption, or for the maintenance of synchronized operation of a plurality of motors.
BACKGROUND ART
In spinning machinery such as a spinning machine, the driving rotational speed of spindle and the driving rotational speed of other peripheral equipment must have fixed synchronous relation with each other.
Recently, with the increasing demand for energy saving or for giving flexible production functions, the use of ring spinning machines of a direct driving system has increased in which system, for each spindle, a motor is provided separately from that for driving peripheral equipment, and the motors are controlled to be driving at a variable speed.
In a spinning machine of a direct driving system, the above-mentioned fixed rotational synchronization is given by the rotational speed control of the motors for the spindles and the peripheral equipment.
In the case of a spinning machine etc. of a direct driving system, while a motor for driving a spindle and a motor for driving other peripheral equipment are operated by a power supply, a fixed synchronous relation in rotational speed is maintained, but if the supply of electricity from the power supply is interrupted by a trouble etc., that is, in a service interruption, the operation of an inverter cannot be continued and motors are rotated by inertia making the speed control impossible; therefore, during a period of time, from a normal operating condition till each of the parts being driven comes to a stop, the above-mentioned synchronous relation can be broken. As a result, there is a probability that a defect is produced in a product or thread cut occurs.
An idea to continue the speed control of a motor even in the case of a service interruption by continuing the operation of an inverter utilizing the regenerative power from the motor is shown in a Japanese patent, laid open No. 62393/86. In the disclosed idea, the following operation is performed: in a service interruption, an instruction to rapidly lower the output frequency of an inverter is issued; when the voltage on the DC side of the inverter is made to an overvoltage with the feedback of the regenerative power, the instruction is suspended to stop the feedback of the regenerative power; when the voltage on the DC side of the inverter is lowered by the stop of the feedback the instruction is issued again, and the feedback operation of regenerative power is performed; such an operation is repeated until the motor is decelerated to a certain speed. Therefore, every time when an instruction is issued, deceleration is performed at the same deceleration rate and the instruction is suspended when the voltage on the DC side of the inverter is made to an overvoltage by regeneration; thus rapid deceleration of the motor and the stop of deceleration is repeated (ON/OFF control), so that a problem results in this case is that smooth deceleration of the motor cannot be performed. Because of this, when the technique is applied to spinning machinery such as spinning machines, there occurs a problem of thread cut or unevenness in thread winding caused by off and on speed change. Since the deceleration rate is set to be large, the quantity of regeneration becomes large, so that the voltage on the DC side rises so high as to induce over-excitation, and a lot of regenerative energy is consumed in the motor, which shortens the period of time in which the voltage of the DC side can be maintained, and a problem occurs that if the duration of time of a service interruption becomes long, restarting of the motor becomes difficult.
SUMMARY OF THE INVENTION
An object of the invention is to provide a motor control device which is capable of controlling the rotation of a motor to be decelerated continuously and smoothly even when a service interruption occurs.
A motor control device according to the present invention comprises: an inverter whose DC side is connected to a power supply, and the AC side thereof is connected to at least a unit of a motor; a speed setting means for giving a speed instruction to the inverter; a service-interruption detection means for detecting a service interruption of the above-mentioned power supply; a voltage detection means for detecting a DC-side voltage of the inverter; a target-voltage generation means for generating a target voltage; a comparison means for comparing the voltage detected by the voltage detection means and the target voltage and for outputting the deviation voltage; and a speed correction means for generating a speed correction signal which is continuously changed in connection with the output of the comparison means; and a DC-side voltage of the inverter is kept at a target voltage value by adding with an adder the output of the speed correction means to the output of the speed setting means for continuously changing the output of the speed setting means, on the direction of a service interruption by the service-interruption detection means. In the motor control device according to the present invention a motor and an inverter are connected even in a service interruption, and the voltage of the DC circuit of the inverter is maintained at a proper value and the control is continued by the regenerative power; therefore the inertial operation of the motor is prevented and the speed is corrected by the speed correction means corresponding to the deviation voltage between the target voltage and the detected voltage, so that the rotation of the motor can be continuously and smoothly decelerated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a basic constitution of the present invention;
FIG. 2 is a time chart showing a DC circuit voltage and a speed instruction in a service interruption according to the present invention;
FIG. 3 shows waveform diagrams of a voltage and a frequency in a service interruption according to the present invention;
FIG. 4 shows time charts of a DC circuit voltage and the rotational speed of a motor in a service interruption in an embodiment of the present invention;
FIG. 5 shows time charts of a DC circuit voltage and the rotational speed of a motor in a service interruption according to the present invention;
FIG. 6 is a block diagram showing a concrete constitution of a first embodiment of the present invention;
FIG. 7 shows time charts of a DC circuit voltage and the rotational speed of a motor in the case where a braking effect is improved in a service interruption in the present invention;
FIG. 8 is a block diagram showing the constitution of a second embodiment of the present invention;
FIG. 9 is a block diagram showing the constitution of a third embodiment of the present invention;
FIG. 10 shows time charts of a DC circuit voltage and the rotational speed of each of the motors in the present embodiment;
FIG. 11 is a block diagram showing the basic constitution of a fourth embodiment of the present invention;
FIG. 12 is a block diagram showing the basic constitution of a fifth embodiment of the present invention; and
FIG. 13 is a block diagram showing the basic constitution of a sixth embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention and the embodiments will be explained referring to FIG. 1 to FIG. 13.
The basic constitution of the present invention will be explained referring to FIG. 1 to FIG. 5.
FIG. 1 shows the basic constitution of the present invention. The DC side of an inverter 103 is connected to a power supply 101 and a motor 105 is connected to the AC side of it. A service-interruption detection means 116 for detecting a service interruption is connection to the power supply 101. A voltage detection means 110 for detecting the voltage on the DC side (hereinafter referred to as DC circuit) of the inverter 103 is connected to the DC side of the inverter 103. To the voltage detection means 110, a comparison means 140 is connected which compares the voltage detected by the voltage detection means 110 with a target voltage produced by a target voltage generation means 112 for generating a target voltage for the DC circuit, and outputs the deviation voltage. The output of the comparison means 140 is connected to a speed correction means 111 provided with a switch means S which is activated when a service interruption is detected by the service-interruption detection means 116. The output of the speed correction means 111 is connected to an adding means 142 which is connected between a speed setting means 107 and the inverter 103.
The operation in the constitution as shown in FIG. 1 will be explained referring to FIG. 2 to FIG. 5.
The voltage detection means 110 detects the DC circuit voltage of the inverter 103; the comparison means 140 compares the output of the voltage detection means 110 with a target voltage E generated by the target voltage generation means 112, and outputs the deviation voltage. The speed correction means 111 outputs a speed correction signal which varies continuously in connection with the deviation voltage. The speed correction signal is arranged to be generated when a service interruption is detected by the service-interruption detection means 116. In other words, in the speed correction means, a switch S is provided which performs ON/OFF operation according to the signal of the service-interruption detection means 116. The switch S can be the one as described in the following: the switch S is provided between the output of the comparison means 140 and the input of the speed correction means 111, and it is made ON by the output of the service-interruption detection means 116 in the case of a service interruption to supply the output of the comparison means 140 to the speed correction means 111; it is also provided for short-circuiting the input and the output of the speed correction means 111 in normal time, and in a service interruption it is made OFF to make the speed correction means 111 workable. In the case of the occurrence of a service interruption, with the ON or OFF of the switch S, the speed correction means is made to be capable of outputting a speed correction signal. The speed setting means 107 generates an output to rotate the motor 105 at a specified speed. In a service interruption, the output of the speed correction means 111 is added to the output of the speed setting means 107 through the adding means 142; thereby, the output of the speed setting means 107 is continuously corrected and the speed instruction is continuously decreased, and the motor 105 is continuously decelerated following the instruction.
The states of the voltages and the speed after the occurrence of a service interruption will be explained referring to FIG. 2 and FIG. 3. As shown in FIG. 2, wherein a service interruption occurs, the output of the service-interruption detection means 116 falls stepwise, and the trailing edge is output as a low level service-interruption signal (FIG. 2(a)). The switch S is activated by the signal, and the speed correction means 111 generates an output in connection with the above-mentioned deviation voltage.
On the other hand, as shown in FIG. 2, the DC voltage VDC starts to fall simultaneously with the time of occurrence of a service interruption t0, and the detected voltage by the voltage detection means 110 becomes lower than the target voltage E given by the target voltage setting means 112 (FIG. 2(c), t0 to t2), so that the deviation voltage between the detected voltage and the target voltage becomes a negative value, and the voltage is input to the speed correction means 111.
The operation after the occurrence of a service interruption is maintained by supplying the regenerated power through the inverter 103 to each constituent element by way of the control power supply 117 (omitted in FIG. 1). Detailed description will be given below. When the deviation voltage is input to the speed correction means 111, it outputs a specified speed correction value obtained by integrating the deviation voltage (FIG. 2(d)); the value is added to the speed instruction from the speed setting means 107; therefore, if a negative deviation is input as mentioned in the above, a correction value corresponding to the deviation voltage is subtracted from the speed instruction given by the speed setting means 107, and the speed instruction for the inverter 103 decreases (FIG. 2(e)).
In an early stage of a service interruption, the number of revolutions of the motor 105 is kept almost as it was by an inertial force, so that the inverter 103 starts regenerative operation after t1 sec from the moment of occurrence of a service interruption caused by the decrease of speed instruction as mentioned in the above, and after t2 sec from the occurrence of the service interruption a state is obtained where the DC voltage E is generated (FIG. 2(c), t2 to t5) by the regenerative power from the motor 105. During such a period of time, the motor is decelerated keeping the DC voltage E, and when the speed is lowered till a certain value, it becomes impossible to generate regenerative power and reaches a stop (FIG. 2(e), t0). The voltage, the speed and the flow of energy during the decelerating operation in t3 to t4 will be explained referring to FIG. 3.
In the present embodiment, since the comparison means 140 and the speed correction means 111 function as a feedback system, as shown in FIG. 3(a), they operate as a feedback control system to make the DC voltage VDC converge at the target voltage E.
In other words as shown in FIG. 2(b), when the deceleration of the motor 105 grows larger than the speed instruction, the regenerative power falls short of keeping the DC voltage VDC and the VDC is lowered much to be lower than the target voltage E, so that the decreasing speed of the speed instruction is decelerated by the decrease in correction value; on the other hand when the deceleration of the motor 105 is slower than the speed instruction the regenerative power becomes surplus, and the DC voltage VDC rises much to be higher than the target voltage E, so that the correction value increases and the decreasing speed of the speed instruction is accelerated. Thereby, the energy flow between the inverter and the motor becomes as shown in FIG. 2(c). Thus the feedback control is executed in the form in which the DC voltage VDC is made to converge at the target voltage E by the increases or the decrease of the correction value, and the motor 105, keeping the DC voltage E, is gradually decelerated with the decrease of rotating energy being consumed in the heating of windings, etc. in the flow of energy as shown in the above. When the speed is lowered much, the quantity of regenerative energy is decreased and the DC voltage begins to fall without being able to maintain the target value. Owing to this, the deviation voltage between the DC voltage and the target value becomes large, and the correction quantity for the speed instruction is increased and the deceleration for the motor is expedited to bring it to a stop.
As described in the above, in the present embodiment a correction signal is obtained by integrating the deviation voltage, so that the correction quantity can be made large by the accumulation of the deviation voltage, that is, the voltage fluctuation can be decreased and the speed stabilization can be achieved. After the occurrence of a service interruption, a shown in FIG. 4, the DC voltage VDC can be kept at the level of the target voltage E for a long time; owing to this even after the occurrence of a service interruption the control of the inverter 103 can be continuously performed; thereby the motor 105 can be decelerated continuously and smoothly while being controlled by the inverter 103.
As described in the above, after the occurrence of a service interruption, energy is regenerated by the motor 105, and the DC voltage VDC is kept at the level of the target voltage E for a long time by a feedback control; thereby the control of the inverter 103 is continuously performed and the electrical relation between the motor 105 and the inverter 103 is maintained; therefore, in the case of a service interruption, after the service is recovered the resumption of operation is easy. After the recovery of the service, the generation of the correction signal by the speed correction means is stopped, so that the motor is accelerated smoothly at a specified rate as shown in FIG. 5.
A first embodiment of the present invention will be explained referring to FIG. 6.
In the present embodiment, the invention is applied to a motor control device to be connected to an AC circuit.
In the present embodiment, a power supply 501 is the AC commercial power supply.
The present invention comprises the following, an addition to the constitution shown in FIG. 1: a converter 502 connected between the inverter 103 and the power supply 501, a smoothing capacitor C connected to the DC circuit of the inverter 103, and an oscillator 508 and a PWM converter 509 being connected in series which are connected between a speed setting means 107 and an adding means 142.
In a voltage detector 116 in the present embodiment, resistors R 509 and R 510 connected in series to each other are connected to the power supply 501 through a rectifier D 501. The junction point of resistors R 509 and R 510 is connected to one of the inputs of a comparator Q 503, and the other input of the comparator Q 503 is connected to a resistor R 511 which generates a criterion voltage whose another end is connected to the positive side of a control power supply 117.
The comparator Q 503 compares a voltage between both ends of the resistor 510 (a divided voltage value of the recited power supply voltage) and the criterion voltage set by the resistor R 511, and detects a service interruption by detecting the voltage between both ends of the resistor R 510 to be lower than the criterion voltage set by the resistor R 511, and generates a signal. In the present embodiment, the comparator Q 503 generates a high level signal in the normal voltage time, and in the lower voltage time, such as a service-interruption time, it generates a low level signal as a service-interruption detection signal.
A voltage detector 110 is composed of resistors R 501 and R 502 connected in series to each other, and the output is taken out from the resistor 502.
A target voltage generating means 112 comprises a resistor R 503 whose one end is grounded and the other end is connected to the negative side of the control power supply 117, and the target voltage is obtained by dividing the voltage applied to the R 503.
The comparison means 140 comprises: an amplifier Q 501; a resistor R 504 connected to the input terminal of the amplifier Q 501 and to the voltage detector 110; and a resistor R 505 connected to the input terminal of the amplifier Q 501 and to the target voltage generation means 112. The amplifier Q 501 further comprises a negative feedback resistor R 506 between the input terminal and the output terminal. The output of the voltage detector 110 and the output of the target voltage generation means 112 are superimposed at the junction point of resistors R 504 and R 505, and the deviation voltage between them is input to the amplifier Q 501 and amplified to be output to the speed corrector 111.
In the present embodiment, the speed corrector 111 comprises an amplifier Q 502, and a resistor R 507, as a proportional element, and a capacitor C 501, as a differential element, being connected in parallel to each other are connected between the output terminal of the comparison means 140 and the input terminal of the amplifier Q 502. A resistor R 508 and a capacitor C 502 connected in series to each other are connected between the input terminal and the output terminal of the amplifier Q 502 as a proportional integration element, and further a switch S is connected in parallel to the proportional integration element. The switch S is normally made ON by the output of the comparator Q 503 in the service-interruption detection circuit 116, and when the voltage is lowered as in the case of a service interruption, it is made OFF.
In the present embodiment, in the normal operation, DC power having a DC voltage E is supplied to the inverter 103 from the commercial power supply 501 through the converter 502. At this time, the inverter 103 drives the motor 105 in a number of revolution corresponding to a speed instruction issued from the speed setter 107. In this case, the instruction from the speed setter 107 is changed to a ramp-shaped signal in a mild acceleration/deceleration circuit 533, and the magnitude of the signal at each point of time in the ramp part is proportional to an output frequency. A specified frequency signal is input to the PWM converter 509 from the oscillator 508 by the above-mentioned signal, and from the PWM converter 509 a PWM signal is generated which makes the inverter 103 output an AC power having a voltage V1 and a frequency F1 corresponding to the ramp signal (speed instruction); by the PWM signal, the inverter 103 is operated and the motor 105 is driven in a number of revolution corresponding to a speed instruction.
In this embodiment, since a PWM system inverter is used, there is no need to control DC voltage VDC; therefore, the voltage VDC is kept at an almost constant voltage which is obtained by simply converting (full wave rectification) an AC voltage received from the commercial power supply 501.
When a service interruption occurs, the DC voltage VDC begins to fall, and the deviation voltage between a detected voltage by the voltage detector 110 and the target voltage becomes a negative value, and it is input to the speed corrector 111.
When the deviation voltage is input to the speed corrector 111, the corrector works to output a specified speed correction value obtained in processing the deviation voltage by proportion, integration or differentiation. The output is added to the speed instruction from the speed setter 107 in the adder 142; when a negative deviation voltage is input, a correction quantity corresponding to the deviation voltage is subtracted from the speed instruction given by the speed setter 507, and the speed instruction for the oscillator 508 is decreased. Owing to this, the motor 105 is made to be in a regenerative condition, and the speed instruction is corrected in relation to the deviation voltage between the voltage of the DC circuit and the target voltage, so that, similar to the case of basic constitution, the motor 105 is decelerated continuously and smoothly in the state where the voltage of the DC circuit is kept at the target voltage value E. The operations after the occurrence of a service interruption are sustained by the control power supply 117 connected to the DC circuit.
In the present embodiment, it is possible to adopt a constitution in which the setting of a target voltage is performed by a microcomputer (CPU). In other words, it is possible to have a constitution in which the functions to be performed by the voltage detector 110, the target voltage setter 112, the mild acceleration/deceleration circuit 533, the adder 142, the oscillator 508, and the PWM converter 509 are executed by the microcomputer (CPU).
In the above constitution, during a deceleration process in a service interrupt in, the microcomputer monitors the speed of the motor 105 (or speed instruction) and when the speed falls to a certain low sped region it resets the target voltage of the DC circuit to a hither value as shown in FIG. 7. Thereupon, the deviation voltage from the detected value is suddenly increased, so that the microcomputer makes the speed deceleration quantity larger. In other words, it controls to decelerate the motor at a larger rate to make the feedback quantity of the regenerative energy large and to push the DC voltage up to a new target voltage level as shown in FIG. 7(b). At this time, the energy increased by square times of a voltage ratio is accumulated in the capacitor C, and the speed of the motor 105 falls to a very low level because of a sudden deceleration as shown in FIG. 7(c). At this time, the microcomputer CPU applies dynamic brakes (DC brake) to the motor through the inverter utilizing increased energy in the capacitor C. Thereby, the motor 105 is securely stopped.
A second embodiment according to the present invention will be explained referring to FIG. 8. In FIG. 8, similar symbols are given to similar constituent elements to those in the firsts embodiment. In the present embodiment, the DC circuits of an "A" system and a "B" system having separate main circuits and control circuits to be able to operate each system independently from each other are connected to each other to form a common DC circuit, and the regenerative energy of a system having larger inertial energy is arranged to be supplied to the other system.
In the present invention, a system which has large inertial energy of a load and a motor and whose energy which can be regenerated for the duration of a service interruption is larger than the consumption energy for continuing the operation of a "B" system is selected to be an "A" system, and the "A" system has similar constitution to that of the first embodiment.
The "B" system has a power supply 501 in common with the "A" system, and comprises a converter 502B connected to the power supply 501, and an inverter 103B having a DC circuit connected to the converter 502B. A motor 205 is connected to the AC side of the inverter 103B, and a smoothing capacitor C is connected to the DC side of the inverter 103B. The control circuit of the inverter 103B comprises: a speed setter 107B, a mild acceleration/deceleration circuit 533B connected in series to the output of the speed setter 107B, an oscillator 508B, and a PWM converter 509B; the output of the PWM converter 509B is connected to the inverter 103B.
In the present embodiment, the DC circuit of the inverter 103 in the "A" system and the DC circuit of the inverter 103B of the "B" system are connected to each other to form a common DC circuit.
Owing to this arrangement, the "A" system can feedback regenerated energy to the common DC circuit when a power supply is interrupted.
When a service interruption occurs in the "A" system, similar to the first embodiment, a negative feedback control is executed to make the voltage of the common DC circuit converge at a target voltage, and continuous and smooth deceleration of the motor is performed. On the other hand, the "B" system independently comprises: a speed setting circuit 507B, the mild acceleration/deceleration control circuit 533B, the oscillator circuit 508B, and the PWM converter circuit 509B; therefore, the "B" system is operated independently in a different way from the "A" system. That is, when the operation is continued in a motor region, the energy fed back from the "A" system can be utilized for the continuation of the operation of the "B" system.
When the regenerative energy of the "A" system is large, a plurality of "B" systems can be connected to the "A" system in the range where the energy of the "A" system can afford to support "B" systems. In place of the converters 502 and 502B of the "A" system and the "B" system a common converter can be used.
A third embodiment according to the present invention will be explained referring to FIG. 9. In the present embodiment, an "A" system comprises a speed ratio circuit 513 connected between an adder 142 and an oscillator 508, and an oscillator 508B and a PWM converter circuit 509B of a "B" system are connected to the speed ratio circuit 513.
The constitution of the "A" system is similar to that of the second embodiment except that the speed ratio circuit 513 is connected between the adder 142 and the oscillator 508. The constitution of the "B" system is similar to that of the second embodiment except that the oscillator circuit 508B and the PWM converter circuit 509B are connected to the speed ratio circuit 513 of the "A" system. In the present embodiment, the speed ratio circuit 513 devices the speed ratio of a motor MB 205 in the "B" system to a motor MA 105 in the "A" system, and the motor MB 205 and the motor MA 105 are operated at a specified speed ratio (synchronized operation).
In the present embodiment, in the case of a power interruption, the feedback of regenerative energy can be done by either of the systems, and the feedback quantity of regenerative energy, that is, the deceleration rate of motors MA and MB in both systems A and B, is automatically controlled to make the voltage of the common DC circuit, regarding A and B systems as a single system, converge at a target voltage value. The operations of motors MA and MB in both systems are continued keeping a specified speed ratio by the speed ratio circuit 513.
In FIG. 10, the relation between the DC voltage VDC and the sped of motors MA and MB during the period of time of continuation of synchronized operation in a service operation. After the occurrence of a service interruption, the motors in both systems are smoothly decelerated in synchronization with each other keeping the VDC of the common DC circuit at a target value. The synchronized operation is normally performed till a low speed state.
A fourth embodiment according to the present invention will be explained referring to FIG. 11. The present embodiment is an example in which the present invention is applied to a motor control device for a ring spinning machine. In the present embodiment, a motor 105 is a spindle motor, and a motor 205 is the one to be used for a peripheral mechanism portion such as a draft mechanism portion. The spindle motor 105 and the motor 205 for the peripheral mechanism are directly connected to a spindle and to a peripheral mechanism as a direct driving system, and according to the scale of a spinning machine, they are provided one unit or a plurality of units respectively. Inverters 103 and 103B are respectively connected to a unit of spindle motor 105 or a plurality of spindle motors 105 and to a unit of motor 205 or a plurality of motors 205 for peripheral mechanism.
In the present embodiment, the constitution is similar to that of the third embodiment except that a converter 502 is commonly provided for inverters 103 and 103B, and a speed ratio circuit 113 is connected between the oscillator circuit 508B of the inverter 103B and the adder 142. In FIG. 3, a smoothing capacitor C of the DC circuit is omitted.
In the present embodiment too, the voltage of the DC circuits of the inverters 103 and 103B are detected and a feedback control is executed so that the voltage can be kept at a target voltage value even in a service interruption, and the speed instruction is corrected corresponding to the deviation voltage between the detected voltage and the target voltage.
In the present embodiment, a signal of a specified frequency is input to a PWM converter 509 from an oscillator 508 according to a speed instruction output form a speed setter 107, and from the PWM converter 509 a PWM signal is generated which makes the inverter 103 output an AC power having a voltage V1 and a frequency f1 corresponding to the speed instruction. Owing to this, the motor 105 is driven in a number of revolution corresponding to the speed instruction.
The speed instruction is supplied also to an oscillator 508B and to a PWM converter 509B through the speed ratio setter 113, and from the PWM converter 509B a PWM signal is output to make the inverter 103B output an AC power having a voltage V2 and a frequency f2 to make the ratio of the number of revolution of the motor 205 to the number of revolution of the motor 105 be a specified value; owing to this, the motor 205 is driving in a number of revolution of a speed ratio given by the speed ratio setter 113 for the speed instruction at the time. In the present embodiment, control is so executed that a specified relation between an instruction and an output can be realized in both voltage and frequency, that is, f1/f2=a constant, and V1/V2=a constant, and the motor 105 and the motor 205 are operated in synchronization with each other.
Because of this, even if the quantity of inertial energy GD maintained by the whole take-up mechanism including the spindle motor 105 is changed by the quantity of thread taken up by a spindle, being independent of the change, a control is automatically obtained which makes motors stop always keeping a proper speed ratio.
When power supply is recovered during a decelerating operation, that is, at the so called recovery of a service interruption, the recovery is detected by a service-interruption detector 116, and the output of the speed corrector 111 is made to zero by the operation of a switch S. Thereupon, the speed instruction returns to a value before the service interruption; in the result, motors 105 and 205 are accelerated again to be brought back to the number of revolution in the normal operating condition.
In the case of the re-acceleration, if a speed instruction rises stepwise, a too heavy current will flow int he motor and also the speed ratio of the motor 105 to the motor 205 will be deviated; therefore it is preferable to change a step-shaped output at a recovery of power to a ramp-shaped output by providing a mild acceleration/deceleration circuit 533 between the speed corrector 111 and the adder 142.
In the present embodiment, regenerative power is automatically controlled corresponding to the inertial quantity in a spindle driving system of a spinning machine; therefore, when the present embodiment is applied to a spinning machine of a direct driving system, etc., always an accurate cooperative stop control of rotational speed can be obtained; even in a service interruption, the operation at an accurate speed ratio is possible and even in the case of a sudden stop of power supply, the fear for the occurrence of thread cut, etc. can be completely eliminated; and the lowering of working ratio, the lowering of quality of products and so on can be sufficiently suppressed.
A fifth embodiment according to the present invention will b explained referring to FIG. 12.
The present embodiment is an example in which an inverter of PAM system is used; in the figure 203A and 203B are inverters of PAM system, and the embodiment is so constituted that each of the motors 105 and 205 are driven by the above-mentioned inverters respectively.
In the case of an inverter of a PAM system, the control on the AC side voltage is executed by controlling a DC input voltage, so that following the converter 502, DC choppers 218A and 218B are provided respectively; the DC voltages Ea and Eb are controlled by the above-mentioned arrangement.
Under normal operating conditions: a voltage instruction output from a voltage setter 219 according to a speed instruction from the speed setter 107 and a detected voltage from the voltage detector 110 are compared; the deviation voltage is supplied to a chopper driving circuit 220A to control the chopper 218A so that the DC voltage Ea can be supplied to the inverter 203A; owing to this, on the AC side of the inverter 203A a voltage V1 corresponding to the speed instruction is obtained. The speed instruction is input also to a frequency setter 221A which functions as a first speed control means; thereby the frequency f1 on the AC side of an inverter 218A is controlled to be the one corresponding to the speed instruction. A feedback control means is substantially composed of a comparator 140 which compares the output of a voltage detector 110A and the output of a voltage setter 219A, and of a speed corrector 111 having a switch S.
The inverter 203B and the chopper 218B are controlled by a voltage setter 219B, a chopper driving circuit 220B and a frequency setter 221B to be able to supply a specified DC voltage Eb to the inverter 203B and also to be able to obtain a voltage V2 and a frequency f2 on the AC side of the inverter 203B; in this case, it is arranged that a speed instruction is input to the voltage setter 219B and the frequency setter 221B through a speed ratio setter 113; because of this the specified relations, f1/f2=a constant, V1/V2=a constant, are given.
Other operations than those mentioned in the above are similar to those in the fourth embodiment.
Therefore, in this embodiment too, always accurate cooperative stop operation of a rotational speed is automatically given, and even in the case of a sudden interruption of power supply caused by a service interruption, the fear of occurrence of thread cut, etc. can be removed completely, and the lowering of working ratio of a spinning machine or the lowering of product quality can be suppressed sufficiently.
A sixth embodiment according the present invention will be explained referring to FIG. 13. The present embodiment is a compromise system composed of the combination of the fourth embodiment and the fifth embodiment, in which a spindle driving motor 105 is driven by a PAM system inverter 203A, and a peripheral mechanism driving motor 205 is driven by a PWM system inverter 103. The other constitution than that mentioned in the above is similar to that of the fourth embodiment or of the fifth embodiment, and the operation of each of the constituent elements is also as explained in previous pages. In the present embodiment: a voltage detector 110 detects a voltage of the DC circuit of the inverter 203A and the voltage is compared with a voltage instruction value of the voltage setter 219A by a comparator 140 to output the deviation voltage; and the output is supplied to a speed corrector 111, and when the switch S is ON, the output of the speed corrector 111 is given as a correction signal. The correction signal is added to a speed instruction of the speed setter 107 to correct the speed instruction continuously; thereby the inverters 203A and 103 are made possible to control the speed of motors 105 and 205 continuously.
According to the present invention, regenerative power is automatically controlled corresponding to the inertia quantity in a spindle driving system of a spinning machine; therefore when the invention is applied to a spinning machine of a direct drive system etc.: always an accurate cooperative stop control of rotational speed can be obtained; even in a service interruption an operation in an accurate speed ratio is possible; even in a sudden interruption of power supply the fear of occurrence of thread cut etc. is completely removed; and the lowering of working ratio or the lowering of product quality, etc. can be sufficiently suppressed.
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The present invention relates to a motor control device using an inverter or inverters, in particular, it relates to a motor control device suitable for the prevention of inertial rotation of a motor or motors or for the maintenance of synchronized operation of a plurality of motors in a service-interruption time; a DC side voltage is compared with a target voltage and a correction signal relating to the deviation voltage is added to a speed instruction for the inverter; thereby in a service-interruption time a motor can be continuously and smoothly decelerated keeping the DC side voltage of an inverter at a target voltage value. By utilizing a motor control device according to the present invention for a spinning machine etc., unevenness in thread winding or thread cut in a service interruption time can be prevented.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of building construction and more specifically, sliding doors.
2. Description of the Prior Art
A variety of electrically operated slidable doors have been provided to achieve a variety of objectives. For example, the automatic doors of an elevator are slidably mounted and disappear into the main walls of the building when opened. Likewise, the typical overhead garage door of a home is slidably mounted and may be operated by an electric motor/worm gear combination. Nevertheless, even in view of all of the slidable doors provided to date, a burglar-proof and wind-proof door which is slidably mounted has not been provided. Typically, a door may be opened by jamming a tool between the door and the frame housing the door. Disclosed herein is a housing having a slidably mounted door with the housing being of unitized construction precluding or reducing the opportunity to remove a single piece from the door housing so as to eventually pry open the door. Likewise, the housing disclosed herein is of one-piece construction providing a more secure seal with the door providing an air-tight seal between the door and housing.
SUMMARY OF THE INVENTION
One embodiment of the present invention is the combination installable in a building having interior and exterior side-by-side walls of a single unitized structure including a doorway portion defining an opening and a storage portion integrally joined together, a single door slidably mounted to the structure, drive means associated with the structure and the door and operable to move the door from an open position within the storage portion to a closed position within the doorway portion, guide means within the structure and extending across the doorway portion and into the storage portion and sized receiving the door being operable to guide the door as the drive means open and closes the door, wherein the improvement comprises, the structure includes a doorway trim integral with the doorway portion with the trim extending outwardly of and adjacent the exterior wall when the structure is mounted to the building, the storage portion contains the drive means, a portion of the guide means and the door when open and is sized to fit completely between the exterior wall and the interior wall.
It is an object of the present invention to provide a new and improved slidably mounted door.
Yet another object of the present invention is to provide a burglar-proof housing for a door wherein the housing is of a unitized integral one-piece construction.
Related objects and advantages of the present invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary front view of a building showing a door construction incorporating the present invention.
FIG. 2 is an enlarged fragmentary cross-sectional view taken along the line 2--2 of FIG. 1 and viewed in the direction of the arrows.
FIG. 3 is an enlarged fragmentary cross-sectional view taken along the line 3--3 of FIG. 1 and viewed in the direction of the arrows.
FIG. 4 is a perspective view of the slidably mounted door and housing incorporating the present invention with the housing and door being removed from the building shown in FIG. 1.
FIG. 5 is an enlarged cross-sectional view taken along the line 5--5 of FIG. 4 and viewed in the direction of the arrows.
FIG. 6 is a fragmentary rear view of the door shown in FIG. 1 with the door shown in the partially open position.
FIG. 7 is the same view as FIG. 6 only showing the door in the completely open position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring now more particularly to FIG. 1, there is shown a portion of a house 20 having a garage 21 with conventional roof 22 and an outside wall 23 constructed from a material, such as brick. A garage door opening 24 is shown with the garage door in the partially closed position providing a small opening of sufficient size, for example, for a person to walk through. A pair of trim portions 27 and 29 are integrally joined to a top trim portion 28 and rest against the external wall 23 of the building. A rain guide 30 is integrally joined to trim portions 27 and 29 and rest atop the ground. Both the trim portions and the rain guide will be described later in the specification.
A perspective view of the door housing in shown in FIG. 4. Housing 31 includes end walls 33 and 34 integrally joined to a pair of side walls 35 and 36 in turn integrally joined to the top wall 32 and bottom wall 37 forming an elongated box. A neck is formed by walls 38 through 41 which in turn are integrally joined to the front wall 35 of housing 31. The neck forms a passageway opening into housing 31 with the passageway being closable by door 25. Housing 31 is a single unitized structure including an end portion 42 forming the doorway or passage formed by walls 38 through 41 and further includes a storage portion 43 wherein the door is stored in the open position along with the drive means for opening and closing the door.
Door 25 is slidably mounted within the housing and is opened and closed by a drive means associated with the housing and the door. Drive means includes an electric motor 44 (FIG. 6) mounted to the front wall 35 of the door housing. Motor 44 includes an output shaft operatively engaged with a rotatably mounted gear 45 in turn engaged with a half-moon shaped gear 46 pivotally mounted by pin 47. Link 48 has a bottom end mounted to end 49 of gear 46 which is located opposite end 50 of gear 46 engaged with gear 45 when the door is in the closed position. The top end of link 48 is pivotally mounted to one end of link 51 having an opposite end with a rotably mounted follower 52 slidably received by slide 53 fixedly mounted to door 25. To open door 25, motor 44 is energized so as to cause gear 46 to pivot in the direction of arrow 54 thereby causing links 51 and 48 to move in the direction of arrow 55 so as to pull door 25 to the completely open position as shown in FIG. 7. Door 25 may be closed by activating motor 44 so as to cause gear 46 to pivot in the direction opposite of arrow 54 thereby moving door 25 and links 48 and 51 in the direction opposite of arrow 55. Motor 44 is connected to a suitable source of electrical energy with a conventional switch provided to allow a person to activate and deactivate the electric motor. For example, a locking push button may be provided outside of the building which will activate only upon receipt of a appropriate configured key. Likewise, a push button may be provided on the inside of the building to activate and deactivate the electric motor.
Guide means are provided within said structure which extend across the doorway portion of the housing and into the storage portion of the housing being sized to receive the door and being operable to guide the door as the drive means open and closes the door. Two different guide means are shown in the drawings. The preferred guide means is shown in FIG. 3 and includes a rod 60 having its opposite ends fixedly secured to the end walls 33 and 34 of the housing. Door 25 is provided with a groove 61 having a plastic coating or slide provided therein to slidably receive rod 60. In addition, a groove 62 is provided in the bottom wall 37 of the housing and slidably receives a rounded projection 63 provided on the bottom edge of door 25. A suitable plastic covering may be provided on projection 63 and within groove 62 to facilitate the sliding motion of the door relative to the housing.
An alternate guide means is shown in FIG. 5 and is identical to the guide means shown in FIG. 3 with the exception that the bottom edge of the door is provided with a groove 64 to slidably receive a second rod 65 having its opposite ends fixedly secured to the end walls 33 and 34 of the housing.
Trim 27, 28 and 29 are integrally attached to walls 40, 39 and 38 (FIG. 4) which in turn are integrally attached to wall 35 of housing 31. Trim 27-29 extend outwardly of and adjacent the exterior wall 23 of the building when the door and door housing are mounted to the building. The storage portion 43 of housing 31 includes and contains the drive means previously described along with a portion of the guide means or guide rails and also the storage portion contains the door when in the open position. Housing 31 is sized to fit completely between the exterior wall 23 and interior wall 70 (FIG. 3) of the building. It is therefore intended that the construction disclosed be installed in the building when the building is initially constructed; however, it is understood that the device disclosed herein may be installed into a completed building, assuming a portion of the interior wall is first removed.
A pair of spaced apart and parallel brackets 80 and 81 (FIG. 4) extend outwardly and to the side of the doorway portion 42 and end wall 34 with brackets 80 and 81 being parallel with the guide means or guide rods 60 and 65. Brackets 80 and 81 are adapted to fittingly receive and fasten to a wooden beam 83 (FIG. 2) of the building. Likewise, a second pair of brackets are provided adjacent end wall 33 (FIG. 4) of the housing to facilitate the securing of housing 31 to the building. Additional brackets 85 may be provided at the top and bottom edges of housing 31. Each of the brackets are provided with suitable nail holes allowing for securing housing 31 to the building.
Wall 41 (FIG. 3) extends outwardly forming rain guide 30 which is positioned atop the ground outwardly of the trim. Back wall 36 (FIG. 3) is provided with an opening 88 aligned and of equal size with the passageway formed by walls 38-41 (FIG. 4) allowing a vehicle to pass through the passageway and housing 31 when the door 25 is in the open position.
The construction disclosed herein includes a variety of advantages as compared to prior doorway constructions. For example, a novel method of enclosing and opening in a building is provided and includes the steps of inserting the housing 31 with door 25 previously described and shown in FIG. 4 within a building and then operating the drive means to open and close the door. The construction is particularly advantageous in that the entire housing may be slipped or inserted between a pair of walls and then fixedly secured thereto without the normal on-site construction of a doorway opening and guide means. Thus, the construction disclosed herein may be assembled and produced at a site remotely located from the construction site. It will be obvious from the above description that the present invention provides a unitized and integral doorway frame having external trim integrally connected to the portion of the frame housing the doorway. Such a construction precludes the easy removal of a board or other portion such as found in the conventional doorway to facilitate the prying of the door from the frame. Likewise, a particularly good air-tight seal is provided between the door and frame. Suitable seals such as felt cloth 90 (FIG. 2) may be provided so as to surround the doorway thereby contacting door 25.
Many variations are contemplated and included in the present invention. For example, the door may be opened by a variety of electrical means operating off either AC or DC current. The door may be made of any shape or size and may be either an exterior or an interior door. A variety of sizes may be provided for the opening. A particular advantage of the construction disclosed herein is that the door does not require any hardware such as doorknobs and hinges. Likewise, in lieu of utilizing the linkage gear combination shown in the drawings, it is possible to open and close the door by a variety of means such as a scissor linkage combined with suitable drive means. The construction disclosed herein is particularly adapted to being molded as a single plastic unit or of any moldable material such as steel, fiberglass, etc. The particular construction disclosed herein alleviates any problems associated with warping, upkeep or maintenance. Such construction may be also used for skylights in addition to conventional doorways.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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A unitized frame housing a slidable door. The main body of the frame is a single molded structure fittable between a pair of walls within a building. Guide means provided within the main body slidably receives a door which is opened and closed by an electric motor. Various linkages and gears connect the electric motor to the door. A neck integrally attached to the main body extends outwardly of the building walls housing the main body of the frame forms a passageway allowing access through the building walls and main body when the door is not closed. The neck flares outwardly providing a trim portion which seats outwardly of the building walls facilitating a smooth boundary between the building and neck. Means are provided for securing the unitized main body to the building.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/970,290, filed Oct. 21, 2004, and is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-363925, filed Oct. 23, 2003, the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic device having a hinge that joins a body and a display. More particularly, the present invention is concerned with the electronic device in which an outer space in the hinge is effectively utilized.
2. Description of the Related Art
Notebook computers have been known for some time as an electronic device with a body and a display which can freely be opened away from the body and closed onto the body.
In the electronic device, for example, as disclosed in Patent Document 1, a power switch is flush with a keyboard included in the body. Moreover, in the electronic device disclosed in Patent Document 2, the power switch is juxtaposed with other operation switches on the lateral side of the body. Moreover, since a motherboard is incorporated in the body, connectors allowing linkage with external equipment or a communication line are disposed on the lateral side or rear side of the body.
[Patent Document 1] Japanese Unexamined Patent Publication No. 2002-108505
[Patent Document 2] Japanese Unexamined Patent Publication No. 2002-7048
In recent years, the electronic device has become more and more compact. There is difficulty in preserving a space, in which components are disposed, in a body and a display alike. Moreover, for realization of thinner equipment, it proves effective to limit the number of components to be incorporated in the body. The present inventor et al. have given attention to a space created at an outer end of the shaft of a hinge other than the body and the display. A power switch or a connector that are conventionally included in the body is disposed in the space in efforts to thin the body.
SUMMARY OF THE INVENTION
In one aspect, an electronic device in accordance with the present invention comprises a body, a display, and a hinge that joins the body and display so that they can freely be opened or closed. A power switch is formed at an edge of the shaft of the hinge.
In another aspect, the electronic device in accordance with the present invention comprises a body, a display, and a hinge that joins the body and display so that they can be freely opened or closed. A port of a connector opens at an end of the shaft of the hinge.
As mentioned above, since the power switch or connector is disposed in a space at an end of the shaft of a hinge which has been left unused as a so-called dead space in the past, the freedom in disposing components in the body or display is expanded accordingly. By devising the layout of the components, thinning of the body and display is facilitated.
According to the electronic device in which the present invention is implemented, a power switch is disposed at an end of the shaft of a hinge. A space in the electronic device that has not been used at all in the past can be utilized effectively. The number of components to be incorporated in the body can be reduced, and the freedom in laying out components is expanded accordingly.
Consequently, the body can be further thinned.
Moreover, since the power switch is disposed away from a keyboard and other operation buttons, the power switch can be prevented from being pressed by mistake and accurately manipulated.
Moreover, according to the electronic device in which the present invention is implemented, a port of a connector opens at an end of the shaft of a hinge. A space present in electronic device that is conventionally not used at all can be utilized effectively. The number of components to be incorporated in a body can be reduced. The freedom in laying out components is expanded accordingly.
Consequently, the body can be further thinned.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electronic device according to an embodiment of the invention in an opened state;
FIG. 2 is a perspective view of the electronic device in a closed state;
FIG. 3 is a plan view of the inside of a lower section 27 of a case 26 of the electronic device;
FIG. 4 is a side view of the lower section 27 as seen along the arrows [ 4 ] and [ 4 ] of FIG. 3 ;
FIG. 5 is a plan view of the built-in components disposed in the case 26 ;
FIG. 6 is a plan view of one surface of a motherboard to be fitted into the case 26 ;
FIG. 7 shows the other surface of the motherboard shown in FIG. 6 ;
FIG. 8 is a plan view of connectors and a flexible wiring board provided in the case 26 ;
FIG. 9 is a front view of the connectors and the flexible wiring board of FIG. 8 ;
FIG. 10 is an enlarged front view of the connectors shown in FIGS. 8 and 9 ;
FIG. 11 is a plan view of a keyboard fitted into the case 26 ;
FIG. 12 is a front view of the keyboard;
FIG. 13 is a rear view of the keyboard;
FIG. 14 is a left-side view of the keyboard;
FIG. 15 is a right-side view of the keyboard;
FIG. 16 is a back side view of the keyboard;
FIG. 17 is a plan view of the inside of the upper section 28 of the case 26 ;
FIG. 18 is a schematic cross section of the inside of the case 26 where heat-generating components are placed;
FIG. 19 is a plan view of the inside of a case 22 ;
FIG. 20 is a side view of the case 22 as seen along the arrows [ 20 ] and [ 20 ] in FIG. 19 ;
FIG. 21 is a plan view of a liquid crystal panel and an inverter circuit board fitted in the inside of the case 22 ;
FIG. 22 is an enlarged plan view of a principal part of the liquid crystal panel being housed in the case 22 ;
FIG. 23 is an enlarged view of one of the two constituent parts of hinges formed at the back of the case 22 ;
FIG. 24 is an enlarged view of the other constituent part of the hinges formed at the back of the case 22 ;
FIG. 25 is a schematic diagram showing a construction of a power switch installed in the constituent part of the hinge shown in FIG. 23 ;
FIGS. 26A and 26B are schematic cross sections of the laminated structure of the case 22 of the electronic device according to the present embodiment;
FIGS. 27A and 27B show the pieces of conductor foil being stuck onto the laminated layer of FIGS. 26A and 26B ;
FIG. 28 shows a resin material being stuck onto edge portions of the laminated layers shown in FIG. 26 ;
FIG. 29 is an enlarged view of the rear portion of the electronic device in an opened state according to the present embodiment; and
FIG. 30 is an enlarged view of the front edge portion of the electronic device in a closed state according to the present embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, an embodiment of an electronic device in accordance with the present invention will be described below. The embodiment is a notebook computer.
FIGS. 1 and 2 show the outer appearances of the electronic device 1 of the present embodiment. The electronic device 1 comprises a body 3 , a display 5 , and two hinges “h” which fasten the display 5 to the body 3 .
The display 5 pivots on the hinges “h” to open away from the body 3 and close onto the body 3 . In FIG. 1 , the display 5 is opened away from the body 3 . In FIG. 2 , the display 5 is closed onto the body 3 .
The body 3 has a case 26 . Disposed in the case 26 as shown in FIG. 5 are a keyboard 11 , a motherboard 30 , a hard-disk drive 32 , a PC card slot 34 , and connectors 40 a - d.
The keyboard 11 is an input unit of the electronic device 1 . The motherboard 30 is the substantially main functional component of the electronic device 1 and receives signals inputted through the keyboard 11 and makes various kinds of processing such as arithmetic processing, control processing, image processing, and processing to output signals to the display 5 .
The motherboard 30 serves as a control circuit board to control individual components such as the keyboard 11 and the display 5 , too.
The case 26 comprises an upper section 28 and a lower section 27 . FIG. 3 is a plan view of the inside of the lower section 27 .
FIG. 4 is a side view of the lower section 27 as seen along the arrows [ 4 ] and [ 4 ] of FIG. 3 .
The lower section 27 looks like a flat box and has an almost rectangular bottom plate 27 a , right and left side plates 27 b and 27 d , and a back plate 27 c . As shown in FIGS. 3 and 4 , the side and back plates 27 b - d are erected on the three sides of the bottom plate 27 a.
The back plate 27 c is erected on the back side of the bottom plate 27 a and has outward-protruding constituent parts 42 a and 42 b of the hinges “h” as shown in FIGS. 3 and 4 .
As shown in FIGS. 3 and 4 , there are cuts 43 a - d in the left side plate 27 b for the connectors 40 a - d and a cut 43 e in the right side plate 27 d for the PC card slot 34 .
The inside of the bottom plate 27 a is provided with a resin mold 45 , which is raised from the inside surface of the bottom plate 27 a to reinforce the lower section 27 against bending and twisting.
A heat-transmitting sheet 47 is stuck on the inside surface of the bottom plate 27 a . The heat-transmitting sheet 47 is positioned near to the center between the right and left sides of the bottom plate 27 a and one-sided toward the back side of the bottom plate 27 a.
The heat-transmitting sheet 47 is, for example, a graphite sheet 0.1 to 1.0 mm thick. Because the heat-transmitting sheet 47 is positioned in an area where the mold 45 does not exist, the heat-transmitting sheet 47 does not float, but is closely stuck onto the inside of the bottom plate 27 a ; accordingly, the heat from heat-generating components to be described later is diffused effectively through the lower section 27 .
An elastic sheet 48 is laid between the heat-transmitting sheet 47 and the bottom plate 27 a . The elastic sheet 48 is rectangular and larger than the heat-generating components. The elastic sheet 48 is positioned substantially in the middle of the lateral width of the lower section 27 within about a half of the bottom 27 a near the wall portion 27 c.
To be specific, the elastic sheet 48 is 0.5-3.0 mm thick and made of Poron (of Rogers Inoac Corporation) which is high-density polyurethane foam whose cells are fine and uniform.
An insulating sheet 49 is overlaid on the heat-transmitting sheet 47 ; accordingly, short circuits between the heat-transmitting sheet 47 , which is made of graphite and conductive, and the motherboard, which is put on the heat-transmitting sheet 47 , are prevented.
The insulating sheet 49 is, for example, a transparent thin film of polyphenylene sulfide. It is as thin as, for example, 0.05-0.3 mm; therefore, it does not prevent heat transmission from the heat-generating components to the heat-transmitting sheet 47 .
The lower section 27 is made of CFRP (carbon fiber reinforced plastics). To be specific, the CFRP consists of six layers 51 a , 51 b , 52 a , 52 b , 53 a , and 53 b as shown in FIG. 26 .
As shown in FIG. 26A , the six layers 51 a , 51 b , 52 a , 52 b , 53 a , and 53 b are pressed together.
Each layer is made of long carbon fibers solidified by epoxy resin. All the fibers of each layer are put side by side in one and the same direction.
To be specific, the carbon fibers of the innermost layers 51 a and 51 b are laid in the longitudinal direction of the electronic device 1 . Accordingly, the carbon fibers of the layer 51 a are parallel to those of the layer 51 b.
The carbon fibers of the intermediate layers 52 a and 52 b are laid in the lateral direction of the electronic device 1 .
The carbon fibers of the outermost layers 53 a and 53 b are laid in the direction at angles of 45° with the longitudinal and lateral directions of the electronic device 1 . Accordingly, the carbon fibers of the layer 53 a are parallel to those of the layer 53 b.
With the above laminated structure, the thin lower section 27 has sufficient strength. As the lower section 27 is thin, the electronic device 1 is also thin, which is an advantage for portable electronic devices in particular.
As shown in FIG. 28 , an insulating layer 56 is formed on the inside surface of the bottom plate 27 a . The insulating layer 56 is made of, for example, nylon (a trade name of Du Pont).
The insulating layer 56 prevents short circuits between the lower section 27 , which is made of CFRP (carbon fiber reinforced plastics) containing conductive carbon fibers, and the motherboard 30 fitted in the lower section 27 .
When the insulating layer 56 made of nylon is heated, it softens and becomes adhesive. By making use of the adhesiveness of the insulating layer 56 , the mold 45 is stuck and fixed to the insulating layer 56 . The mold 45 has bosses with threaded holes, etc.
As shown in FIG. 28 , the front edge of the lower section 27 is provided with a resin cover 45 a . By making use of the adhesiveness of the insulating layer 56 , the cover 45 a is stuck onto the insulating layer 56 to cover the front edge of the lower section 27 . Thus, loose ends of carbon fibers, if any, at the front edge of the lower section 27 are covered up.
As shown in FIG. 3 , because the resin cover 45 a extends along the front edge of the lower section 27 , it serves as a beam, too, reinforcing the lower section 27 against bending and twisting.
The resin cover 45 a and the mold 45 are made of nylon as well as the insulating layer 56 ; accordingly, the cover 45 a and the mold 45 are stuck on the insulating layer 56 sufficiently. As shown in FIG. 28 , a groove 54 is made in the surface of the resin cover 45 a which comes in contact with the insulating layer 56 . When the insulating layer 56 is heated and softened and the cover 45 a is stuck on the insulating layer 56 , surplus softened, adhesive nylon enters into the groove 54 .
Thus, the surplus softened, adhesive nylon is prevented from leaking out through the joint between the lower section 27 and the cover 45 a . If the surplus softened, adhesive nylon leaks out, the appearance of the electronic device 1 is spoiled.
Because the right and left side plates 27 b and 27 d are erected on the right and left sides, respectively, and the back plate 27 c is erected on the back side of the bottom plate 27 a , these plates 27 b , 27 c , and 27 d play the role of the cover 45 a.
Now, the motherboard to be fitted in the lower section 27 will be described below by referring to FIGS. 6 and 7 . FIG. 6 shows the upper surface of the motherboard 30 ; FIG. 7 , the lower surface. A central processor 58 is mounted on the upper surface. An image processor 60 and a plurality of semiconductor memories 62 are mounted on the lower surface. Although not shown in FIGS. 6 and 7 , many other components are mounted on both the surfaces of the motherboard 30 .
The central processor 58 and the image processor 60 are semiconductors and generate heat when they function. The central processor 58 and the image processor 60 are so positioned that they do not overlap with each other.
The motherboard 30 comprises a multi-layer printed circuit board and the central processor 58 , the image processor 60 , the semiconductor memories 62 , and other components (not shown) mounted on both the surfaces of a multi-layer printed circuit board and is the substantial body of the electronic device 1 in terms of functions of the electronic device 1 .
The multi-layer printed circuit board is made by the buildup method as follows. A two-layer printed circuit board (hereinafter “intermediate two-layer printed circuit board”) is laid on each of the upper and lower surfaces of an innermost two-layer printed circuit board. A single-layer printed circuit board is laid on the upper surface of the upper intermediate two-layer printed circuit board; a single-layer printed circuit board, on the lower surface of the lower intermediate two-layer printed circuit board. A single-layer printed circuit board is laid on the upper surface of the upper single-layer printed circuit board; a single-layer printed circuit board, on the lower surface of the lower single-layer printed circuit board. Thus, a ten-layer printed circuit board is made. The buildup method enables us to do wiring efficiently and high-density mounting of parts.
The connectors 40 a - d shown in FIGS. 8-10 are also fitted in the lower section 27 . The connectors 40 a - d are connected to the motherboard 30 through a flexible wiring board 67 . Namely, the connectors 40 a - d are connected to wires at one end of the flexible wiring board 67 , and the other end 67 a of the flexible wiring board 67 is inserted into a connector mounted on the motherboard 30 .
As shown in FIG. 10 , the connector 40 b is provided two flanges 64 protruding from the right and left shorter sides of its socket. By fixing the flanges 64 to the left side plate 27 b by using, for example, screws, the connector 40 b can be fixed to the left side plate 27 b . The connector 40 c has the same flanges 64 as the connector 40 b.
The keyboard 11 shown in FIGS. 11-16 is fitted to the lower section 27 . FIG. 11 is a plan view of the keyboard 11 . FIGS. 12 and 13 are front and rear views, respectively, of the keyboard 11 . FIGS. 14 and 15 are left and right side views, respectively, of the keyboard 11 . FIG. 16 is a bottom view of the keyboard 11 .
The keyboard 11 comprises a case 37 , input keys 13 , a pointing device 14 called “track point,” and a cover 36 .
The case 37 is made of, for example, magnesium and in the shape of a flat box, having a key-arrangement area and side plates erected around the key-arrangement area.
The key-arrangement area is in the shape of an almost rectangular flat plate and the side plates are formed, as a single piece, at the right, left, top, and bottom sides of the key-arrangement area.
As described above, the case 37 is not a flat plate, but in the shape of a flat box, having the side plates; accordingly, its rigidity is high. When a user presses keys 13 , the case 37 does not warp, giving good repulsion to the fingers of the user. Thus, the feeling of key operation is good.
The four sides of each key of an ordinary keyboard are inclined, whereas the four sides of input keys 13 are not inclined. Accordingly, the occupancy area of each input key 13 is smaller than that of an ordinary key. Accordingly, the gaps between input keys 13 can be widened to prevent the user from pressing wrong input keys 13 .
The cover 36 has cuts in it, and the input keys 13 and the pointing device 14 are exposed through the cuts. The key-arrangement area is covered with the cover 36 . Thus, the gaps between input keys 13 are covered and, hence, dust and water are prevented from entering through the gaps. The cover 36 and the input keys 13 are made of, for example, ABS resin.
Now, the upper section 28 of the case 26 will be described below by referring to FIG. 17 . FIG. 17 is a plan view of the inside of the upper section 28 which faces the inside of the lower section 27 shown in FIG. 3 .
The upper section 28 is almost rectangular and has approximately the same area as the lower section 27 . The upper section 28 has a large cut 80 in its front area wherein the input keys 13 and the pointing device 14 are arranged.
The reference numeral 81 in FIG. 17 is a covered area. Outward-protruding constituent parts 74 a and 74 b of the hinges “h” are formed at the back side of the covered area 81 .
A heat-transmitting sheet 72 is stuck to the inside of the covered area 81 . The heat-transmitting sheet 72 is positioned near to the center between the right and left sides of the covered area 81 .
The heat-transmitting sheet 72 is made of, for example, graphite and 0.1-1.0 mm thick. The heat-transmitting sheet 72 is shaped and has cuts in it so as to avoid bosses and ribs erected inside the covered area 81 . Thus, the covered area 81 is not floated over the inside surface of the covered area 81 , but closely stuck onto the inside surface; accordingly, the heat from heat-generating components is effectively diffused through the upper section 28 .
An elastic sheet 83 is laid between the heat-transmitting sheet 72 and the inside surface of the covered area 81 . The elastic sheet 83 is rectangular and larger than the heat-generating components in contact with the heat-transmitting sheet 72 . The elastic sheet 83 is positioned near to the center between the right and left sides of the covered area 81 .
To be specific, the elastic sheet 83 is 0.5-3.0 mm thick and made of Poron (of Rogers Inoac Corporation) which is high-density polyurethane foam whose cells are fine and uniform.
An insulating sheet (not shown) is overlaid on the heat-transmitting sheet 72 ; accordingly, short circuits between the heat-transmitting sheet 72 , which is made of graphite and conductive, and the motherboard 30 , which is put on the heat-transmitting sheet 72 , are prevented.
The insulating sheet is, for example, a transparent film of polyphenylene sulfide. It is as thin as, for example, 0.05-0.3 mm; therefore, it does not prevent heat transmission from the heat-generating components to the heat-transmitting sheet 72 .
The lower section 27 and the upper section 28 are coupled by, for example, screws. At this time, the keyboard 11 , motherboard 30 , hard-disk drive 32 , and PC card slot 34 are fitted in the inside of the lower section 27 .
The cooling mechanism for the central processor 58 and the image processor 60 , which are mounted on the upper and lower surfaces, respectively, of the motherboard 30 and generate heat, will be described below by referring to FIG. 18 .
The lower surface, on which the image processor 60 is mounted, of the motherboard 30 faces the inside of the lower section 27 . The upper surface, on which the central processor 58 is mounted, faces the inside of the upper section 28 .
The image processor 60 is in contact with the part of the heat-transmitting sheet 47 raised by the elastic sheet 48 . In this way, the image processor 60 is put in close contact with the heat-transmitting sheet 47 by the elasticity of the elastic sheet 48 . Thus, air is precluded from between the image processor 60 and the heat-transmitting sheet 47 and the heat from the image processor 60 is efficiently transmitted to the heat-transmitting sheet 47 .
The heat transmitted to the heat-transmitting sheet 47 is diffused through the heat-transmitting sheet 47 and the lower section 27 . Thus, overheat of the image processor 60 is prevented.
The central processor 58 is in contact with the part of the heat-transmitting sheet 72 lowered by the elastic sheet 83 . In this way, the central processor 58 is put in close contact with the heat-transmitting sheet 72 by the elasticity of the elastic sheet 83 . Thus, air is precluded from between the central processor 58 and the heat-transmitting sheet 72 and the heat from the central processor 58 is efficiently transmitted to the heat-transmitting sheet 72 .
The heat transmitted to the heat-transmitting sheet is diffused through the heat-transmitting sheet 72 and the upper section 28 . Thus, overheat of the central processor 58 is prevented.
The central processor 58 and the image processor 60 are so positioned that they do not overlap with each other and, hence, the heat from the central processor 58 and the image processor 60 is not concentrated at a single spot. Beside, this arrangement of the central processor 58 and the image processor 60 enables the reduction of the distance between the lower section 27 and the upper section 28 and, hence, the reduction of the body 3 .
The semiconductor memories 62 (see FIG. 7 ) mounted on the lower surface of the motherboard 30 are also in contact with the heat-transmitting sheet 47 and their heat is diffused through the heat-transmitting sheet 47 .
The hard-disk drive 32 as that is a storage device, which is positioned to the left of the motherboard 30 in FIG. 5 , will be described below.
As shown in FIG. 3 , ribs 46 are formed in the four corners of a hard disk drive-mounting space 44 in the lower section 27 . In addition, as shown in FIG. 17 , ribs 78 are formed in the four corners of a hard disk drive-mounting space 76 in the upper section 28 .
Accordingly, the hard-disk drive 32 is supported by the ribs 46 and 78 , a gap of the height of ribs 78 kept between the top surface of the hard-disk drive 32 and the inside surface of the upper section 28 , a gap of the height of ribs 46 kept between the bottom surface of the hard-disk drive 32 and the inside surface of the lower section 27 .
There are small gaps in spots, where the connectors 40 a - d (see FIG. 5 ) are mounted to expose their sockets, of the left side plates of the lower section 27 and the upper section 28 . The inside and the outside of the case 26 are connected by the small gaps. The space in which the motherboard 30 is fitted and the outside of the case 26 can be connected by the small gaps and the gaps on and under the hard-disk drive 32 .
Accordingly, the discharge of heat from the central processor 58 and the image processor 60 can be accelerated. Besides, the hard-disk drive 32 can be air-cooled.
The connectors 40 a - d are connected to the motherboard through the flexible wiring board 67 (see FIG. 8 ). The flexible wiring board 67 is routed through the gap between the bottom surface of the hard-disk drive 32 and the inside surface of the lower section 27 .
Because the connectors 40 a - d are not mounted directly on the motherboard 30 , shock at the time of connection and disconnection of external cables to and from the connectors 40 a - d is absorbed by the flexible wiring board 67 . Thus, the shock is not transmitted to the motherboard 30 , damage to and positional slippage of the motherboard 30 prevented.
As shown in FIGS. 8 and 9 , the connectors 40 b and 40 c are disposed so that the right flange 64 of the connector 40 b and the left flange 64 of the connector 40 c overlap with each other. The two flanges 64 overlapping with each other are fixed to the left side plate of the lower section 27 with, for example, a screw. Thus, the space to mount the connectors 40 a - d is saved by the space of one flange 64 .
As shown in FIG. 5 , the PC card slot 34 is disposed at the right side of the case 26 . The PC card is the standards for card-type peripheral devices established jointly by PCMCIA (Personal Computer Memory Card International Association) and JEIDA (Japan Electronic Industry Development Association).
The keyboard 11 is disposed in the space along the front of the case 26 . The input keys 13 and the pointing device 14 are exposed to the outside through the cut 80 in the upper section 28 .
As described above, the motherboard 30 , hard-disk drive 32 , and PC card slot 34 are disposed in the space along the back of the case 26 and the keyboard 11 is disposed in the space along the front of the case 26 .
Cuts are made in the right and left sides of the motherboard 30 to avoid the hard-disk drive 32 and the PC card slot 34 . The keyboard 11 does not overlap with the central processor 58 or the image processor 60 mounted on the motherboard 30 or the hard-disk drive 32 or the PC card slot 34 .
As described above, because built-in components are arranged without their overlapping with one another, the body 3 can be made thin.
Part of the motherboard 30 is placed under the keyboard 11 , but the central processor 58 and the image processor 60 , which account for a large part of the thickness of the motherboard 30 , do not overlap with the keyboard 11 . Accordingly, the body 3 is not prevented from being made thin. An insulating sheet made of, for example, polycarbonate is laid between the part of the motherboard 30 overlapping with the keyboard 11 and the keyboard 11 in order to prevent short circuits between the case 37 of conductive magnesium and the motherboard 30 . The motherboard 30 and the keyboard 11 may be arranged so that they do not overlap with each other at all.
Because the heat-generating central processor 58 and image processor 60 do not overlap with the keyboard 11 , the heat of neither the central processor 58 nor the image processor 60 is transmitted to the keyboard 11 to annoy the user.
Because the central processor 58 and the image processor 60 are disposed in the space along the back side of the case 26 and the keyboard 11 is disposed in the space along the front side of the case 26 , the user can operate the keyboard 11 without touching the upper section 28 covering the central processor 58 and the image processor 60 .
The central processor 58 and the image processor 60 are positioned near to the center between the right and left sides of the case 26 ; accordingly, less heat is transmitted from the central processor 58 and the image processor 60 to the user's right and left hands which tend to be positioned toward the right and left sides of the keyboard 11 , respectively. When the user moves the electronic device 1 with the display 5 opened, the user holds the right and left sides of the part of the body 3 behind the keyboard 11 ; accordingly, less heat is transmitted from the central processor 58 and the image processor 60 to the hands of the user.
Because the most heat-generating image processor 60 is mounted on the lower surface of the motherboard 30 , less heat is transmitted from the image processor 60 to the top, or keyboard, side of the body 3 , less annoying the user.
Now, the display 5 will next be described. The display 5 comprises a case 22 (see FIG. 19 ), a liquid crystal panel 7 (see FIG. 21 ) housed in the case 22 , and an inverter circuit board 93 (see FIG. 21 ).
FIG. 19 is a plan view of the inside of the case 22 . FIG. 20 is a side view of the case 22 as seen along the arrows [ 20 ] and [ 20 ] in FIG. 19 . The case 22 is almost rectangular and side plates are erected at the right and left sides of the case 22 .
Outward-protruding constituent parts 87 a and 87 b of the hinges “h” are formed at the right and left ends of the back side of the case 22 .
Molds 85 a - d are provided inside the case 22 . The molds 85 a - d are disposed so that they enclose the four sides of the case 22 and reinforce the case 22 against bending and twisting.
In the same way as the lower section 27 , the case 22 is made of CFRP (carbon fiber reinforced plastics). To be specific, the CFRP consists of six layers 51 a , 51 b , 52 a , 52 b , 53 a , and 53 b as shown in FIG. 26 .
As shown in FIG. 26A , the six layers 51 a , 51 b , 52 a , 52 b , 53 a , and 53 b are pressed together.
Each layer is made of long carbon fibers solidified by epoxy resin. All the fibers of each layer are put side by side in one and the same direction.
To be concrete, the carbon fibers of the innermost layers 51 a and 51 b are laid in the longitudinal direction of the electronic device 1 . Accordingly, the carbon fibers of the layer 51 a are parallel to those of the layer 51 b.
The carbon fibers of the intermediate layers 52 a and 52 b are laid in the lateral direction of the electronic device 1 .
The carbon fibers of the outermost layers 53 a and 53 b are laid in the direction at angles of 45° with the longitudinal and lateral directions of the electronic device 1 . Accordingly, the carbon fibers of the layer 53 a are parallel to those of the layer 53 b.
With the above laminated structure, the thin case 22 has sufficient strength. As the case 22 as well as the lower section 27 is thin, the electronic device 1 is also thin, which is an advantage for portable electronic devices in particular.
As shown in FIG. 28 , an insulating layer 56 is formed on the inside surface of the case 22 . The insulating layer 56 is made of, for example, nylon (a trade name of Du Pont).
The insulating layer 56 prevents short circuits between the case 22 made of CFRP containing conductive carbon fibers and the liquid crystal panel 7 , the inverter circuit board 93 , etc. housed in the case 22 .
When the insulating layer 56 made of nylon is heated, it softens and becomes adhesive. By making use of the adhesiveness of the insulating layer 56 , the molds 85 a - d are stuck and fixed to the insulating layer 56 . Because the molds 85 a - d are also made of nylon, they stick well to the insulating layer 56 .
As shown in FIG. 28 , the front and back edges of the case 22 are provided with the molds 85 a and 85 b , respectively. By making use of the adhesiveness of the insulating layer 56 , the molds 85 a and 85 b are stuck onto the insulating layer 56 to cover the front and back edges of the case 22 . Thus, loose ends of carbon fibers, if any, at the front and back edges of the case 22 are covered up.
Because the molds 85 a and 85 b extend along the front and back edges of the case 22 , they serve as beams, too, reinforcing the case 22 against bending and twisting.
As shown in FIG. 28 , grooves 54 are made in the surfaces of the molds 85 a and 85 b which come in contact with the insulating layer 56 . When the insulating layer 56 is heated and softened and the molds 85 a and 85 b are stuck on the insulating layer 56 , surplus softened, adhesive nylon enters into the grooves 54 .
Thus, the surplus softened, adhesive nylon is prevented from leaking out through the joints between the case 22 and the molds 85 a and 85 b . If the surplus softened, adhesive nylon leaks out, the appearance of the electronic device 1 is spoiled.
Because the case 22 has the right and left side plates, these side plates play the role of the molds 85 a and 85 b.
The opposite of the inside surface of the case 22 in FIG. 19 is a facing, which is the surface of one of the outmost layers 53 a and 53 b . A layer of self-cure resin is formed on the facing.
The layer of self-cure resin is formed by spraying, for example, acrylic or urethane resin with cross-linked structure and high capability of elastic recovery to the facing of the case 22 .
If a flaw or dent is made in the self-cure resin layer on the facing of the case 22 , it exists as a flaw or dent temporarily and then it disappears gradually because of the high capability of elastic recovery of the self-cure resin layer.
The self-cure resin used in the present embodiment is transparent and colorless. It gives luster to the facing of the case 22 made of dull black CFRP (carbon fiber reinforced plastics) to improve the appearance of the case 22 .
The unit consisting of the liquid crystal panel 7 and the inverter circuit board 93 shown in FIG. 21 is fitted in the inside of the case 22 of FIG. 19 . Because the inverter circuit board 93 does not overlap with the liquid crystal panel 7 as shown in FIG. 21 , the display 5 is thin. The thinness of the display 5 as well as the thinness of the body 3 contributes to the thinness of the electronic device 1 .
The liquid crystal panel 7 has a back-light unit including a light source, light-guiding plates, etc. A fluorescent lamp, for example, is used as the light source, which may be built in the top of the liquid crystal panel 7 .
As shown in FIG. 19 , a piece of conductor foil 89 such as copper foil is stuck on the inside surface of the case 22 to earth the liquid crystal panel 7 to the case 22 .
In general, there exists a thin resin film (for example, an epoxy-resin film) on the surface of a base plate made of CFRP; accordingly, the surface of the base plate does not have stable conductivity. As in FIG. 27 , if a piece of copper foil 89 is pressed onto a resin film 127 on the surface of the outermost layer 53 a , the piece of copper foil 89 pushes aside the resin film 127 and sticks to the layer 53 a to secure a stable electric connection between the piece of copper foil 89 and the conductive carbon fibers of the layer 53 a.
As shown in FIG. 22 , a leaf spring 95 is fitted between the piece of copper foil 89 on the inside of the case 22 and a metal bracket 91 a mounted on a metal frame 91 of the liquid crystal panel 7 to electrically connect the liquid crystal panel 7 to the piece of copper foil 89 . The tip of the leaf spring 95 is in elastic contact with the piece of copper foil 89 and the base of the leaf spring 95 is fixed to the metal bracket 91 a by, for example, a screw.
Thus, the liquid crystal panel 7 is electrically stably connected to the case 22 with a large area to protect the liquid crystal panel 7 from external magnetic noises and prevent the magnetic noises generated by the liquid crystal panel 7 from affecting external components and devices.
As shown in FIG. 1 , a frame 24 is fitted to the case 22 housing the liquid crystal panel 7 to expose the screen 70 of the liquid crystal panel 7 .
The hinges “h” to connect the body 3 and the display 5 will next be described below.
When the lower section 27 of FIG. 3 and the upper section 28 of FIG. 17 are combined, the part 42 a of the lower section 27 and the part 74 a of the upper section 28 are combined to become a cylinder of a hinge “h.” One hinge h (the left hinge h in FIGS. 1 and 2 ) is constructed when the cylinder of the case 26 is rotatably connected with the constituent part 87 a of the case 22 shown in FIG. 19 .
On the other hand, when the lower section 27 of FIG. 3 and the upper section 28 of FIG. 17 are combined, the part 42 b of the lower section 27 and the part 74 b of the upper section 28 are combined to become another cylinder. The other hinge h (the right hinge h in FIGS. 1 and 2 ) is constructed when the cylinder of the case 26 is rotatably connected with the constituent part 87 b of the case 22 shown in FIG. 19 .
As shown in FIG. 23 , a hinge fitting 97 is provided on the other hinge h. One end of the hinge fitting 97 is fixed to the cylinder of the case 26 by, for example, a screw. The constituent part of the case 22 receives a cylindrical portion of the hinge fitting 97 , and the case 22 , or the display 5 , is relatively rotatable about the cylindrical portions of the hinge fittings 97 .
Further, as shown in FIG. 23 , a power switch 20 is provided on an edge of the hinge's shaft (a side portion which does not face the other hinge with respect to the longitudinal direction of the axis of the hinge, namely, a side portion on the right in FIG. 23 ). (Also, see FIG. 2 )
The power switch 20 comprises, as shown in a schematic diagram of FIG. 25 , a pressing operation part 101 , a light-emitting element 121 , a switch 125 , and a contact 123 .
The pressing operation part 101 can be pressed along the longitudinal direction of the axis of the hinge (the direction shown by the arrow in FIG. 25 ). The light-emitting element 121 is placed inside the pressing operation part 101 . The light-emitting element 121 is, for example, a light-emitting diode and is mounted on a surface, which faces the pressing operation part 101 , of the circuit board 103 joined with the pressing operation part 101 .
The switch 125 is mounted on the other side of the circuit board 103 . The contact 123 provided facing the switch 125 is fixed to the constituent part of the case 22 .
As shown in FIG. 2 , the pressing operation part 101 is exposed to the outside. When the pressing operation part 101 is pressed in the direction of the arrow in FIG. 25 by a user's finger and so on, it moves toward the contact 123 together with the circuit board 103 , and the light-emitting element 121 and the switch 125 mounted thereon.
When the switch 125 is pressed touching the contact 123 , the power is turned off when the power of the electronic device 1 is on and the power is turned on when the power of the electronic device 1 is off.
When the pressing operation part 101 is pressed sideways by the user's finger, the direction of the movement tends to be inclined compared to when it is pressed downward. To cope with such a problem, the surface of the switch 125 which meets the contact 123 is curved. Therefore, in spite of a little inclination, the contact and the switch 125 can meet stably (for example, compared to when the surface is flat, the contact area can be larger) and the power can be turned on or off reliably.
Incidentally, the pressing operation part 101 has substantially a round shape, and is disposed so that the rotation axis of the hinge will pierce substantially the center of the round pressing operation part 101 . Consequently, when the power switch is pressed in the direction of the rotation axis of the hinge, the power supply is turned on or off. Since the switch 125 is pressed in the direction of the rotation axis of the hinge, the pressing operation part 101 that is large for the thickness of the display 5 or the body 3 can be employed. Consequently, the power switch 20 is reliably manipulated.
According to the present embodiment, the pressing operation part 101 that is large for the thickness of the display 5 or body 3 is adopted. As long as the pressing operation part 101 that is pressed in the direction of the rotation axis of the hinge is adopted, the pressing operation part 101 (switch or button) that is larger than a switch (button) to be formed in the lateral side of the case can be formed because of the thicknesses of the cases 22 , 24 , 27 , and 28 that determine the shapes of the display 5 and body 3 respectively.
The usage of the space in the hinge is not limited to the power switch as it is in the present embodiment. Alternatively, a switch (button) for any purpose other than the purpose of power supply may be formed. For example, when electronic device includes an imaging means that has a CCD or the like, the space in the hinge may be used to form a shutter button required for producing still images or an imaging start/stop button required for producing a motion picture.
Further, if all or a part (for example, a ring portion of the outer edge) of the portion of the pressing operation part 101 exposed to the outside is formed as a light-transmission part made of transparent resin material, the light from the light-emitting element 121 can be guided to the outside through such a light-transmission part. Accordingly, when the power is on, for example, a red light can be turned on to have a user confirm its state visually. Alternatively, when in a power-saving standby state, a green light can be turned on and off to have the user confirm its state visually.
The light transmission part of the pressing operation part 101 is always exposed to the outside regardless of the electronic device 1 being opened or closed. Therefore, even if the display 5 is closed while the power is on, the state can be checked by the light visible through the light transmission part.
Also, when carrying the electronic device 1 in a bag or so with the display 5 closed, the pressing operation part 101 may be pressed by an article in the bag. Accordingly, in the present embodiment, as in FIG. 23 , a closed-state detecting switch 105 is provided on the constituent part of the case 22 , and a closed-state detecting contact 106 is provided on the hinge fitting 97 as a single piece.
When the display 5 is closed onto the body 3 by the relative rotation of the constituent part of the case 22 and the hinge fitting 97 , the closed-state detecting switch and the closed-state detecting contact 106 meet, turning on the closed-state detecting switch 105 . The closed-state detecting switch 105 is kept turned on while the display 5 is closed onto the body 3 .
Accordingly, when the closed-state detecting switch 105 is on, that is, when the display is closed, the electronic device 1 can be prevented from being turned on even if the pressing operation part 10 is pressed. Alternatively, when it is closed while the power is on and the closed-state detecting switch 105 is turned on, it becomes possible to automatically turn the power off or to send the electronic device 1 into a power-saving standby state.
Incidentally, a control mode is not limited to the mode of controlling the power supply according to whether the display is open or closed, but any other control mode may be adopted.
For example, when electronic device has an imaging means that includes a CCD, the action of a shutter button required for producing still images or an imaging start/stop button required for producing a motion picture may be controlled based on whether the case is open or closed. For example, control is extended so that when the case is closed, even if the button is pressed, a still image or a motion picture will not be produced.
Incidentally, the means for detecting whether the display 5 is open or closed is not limited to the one employed in the present embodiment, but any other means will do. For example, a magnetic body included in the display 5 , and a Hall sensor that is located in a region in the body 3 in which the Hall sensor is opposed to the magnetic body and that detects a magnetic field strength may be used to detect whether the display is open or closed.
Further, as in FIG. 24 , a connector 19 for an AC adapter is provided on the edge (side portion on the left in FIG. 24 ) of the shaft of the hinge opposite the hinge in which the power switch 20 is provided (Also, see FIG. 1 ). A socket for the connector 19 is always exposed to the outside regardless of the opened and closed state of the electronic device 1 .
Moreover, the connector 19 is disposed so that the rotation axis of the hinge and the axis of the connector 19 will be aligned with each other.
Since the port of the connector 19 opens in the direction of the rotation axis of the hinge, the connector that is large for the thickness of the display 5 or body 3 can be employed.
According to the present embodiment, the connector 19 that is large for the thickness of the display 5 or body 3 is employed. As long as the port of the connector opens in the direction of the rotation axis of the hinge, a connector larger than the one formed in the lateral side of any of the cases 22 , 24 , 27 , and 28 , which determine the shapes of the display 5 and body 3 respectively, can be formed because of the thicknesses of the cases.
The usage of the space in the hinge is not limited to the connector for connection of an AC adaptor as it is in the present embodiment. A connector for any purpose other than the purpose of power supply may be formed. For example, a connector for connection of a headphone may be formed. Moreover, the shape of the port of the connector is not limited to a round but may be a rectangle. For example, a connector for plugging in of a universal serial bus (USB) 2.0 may be formed.
As in FIG. 24 , a cable 112 for connecting the connector 19 with the motherboard 30 of the body 3 is not directed straight from the connection with the connector 19 to the side of the body 3 (lower position in FIG. 24 ). On the contrary, the cable 112 detours around the area near the connection with the connector 19 so that it forms a loop on the side of the display 5 and is drawn to the side of the body 3 .
The detouring portion of the cable 112 forms a loop being guided by a boss 114 erected inside the case 22 and guide members 118 , 119 a , 119 b.
Accordingly, even if opening and closing of the display 5 away from and onto the body 3 are repeated, the connection (soldered, for example) to the connector 19 of the cable 112 is prevented from receiving a concentrated excessive load such as twisting and pulling, thereby a break in the cable being prevented.
Further, the guide members 119 a and 119 b restrict the rising of the detouring portion of the cable 112 from the inside surface of the case 22 so that the looped detouring portion can be held stably.
Further, the previously described power switch 20 shown in FIG. 23 is configured such that a cable (not shown) connected to the connector 110 via the flexible wiring board 108 formed on the inside surface of the case 22 is drawn to the side of the body 3 . Therefore, again, the cable is not drawn directly from the power switch 20 to the body 3 . This is because the previously described inverter circuit board 93 is not provided on the inside surface of the case 22 on this side and there is enough space for arranging the above flexible wiring board 108 and the connector 110 .
As described above, the power switch 20 and the connector 19 are provided on the edge portion of the shaft of the hinge, which has not been used at all, namely, a dead space. Therefore, components of the body 3 and the display 5 can be positioned more freely. By suitably arranging those components, the body 3 and the display 5 can be made thinner as described above. Further, since the power switch 20 is positioned away from the keyboard 11 and other operation buttons 15 a - 15 c (see FIG. 1 ), it is prevented from being mistakenly pressed, ensuring reliable operation. Thus, mistakes such as turning the power off while the device is in use can be avoided.
The embodiment has been described by taking for instance the electronic device including the display 5 and body 3 that can be freely turned on the hinges to be open or closed. The present invention can be adapted to any other type of electronic device as long as a first case and a second case can be freely turned on hinges to be open or closed. For example, electronic device including two displays that can be freely turned on hinges to be open or closed will do.
Moreover, according to the aforesaid embodiment, the hinges are formed on the edge of the case of electronic device away from a user under the normal specifications. Alternatively, electronic device whose right and left cases are turned on hinges to be open or closed will do.
Functions such as left-clicking, right-clicking, and scrolling are assigned to the three operation buttons 15 a - c disposed on the front edge about the center between the right and left sides of the body 3 .
Also, as shown in FIGS. 1 and 2 , there is a battery 9 provided between the hinges h.
Further, as shown in FIGS. 1 and 2 , a bottom surface of the lower section 27 is not flat, and the rear end on the side of the hinges h is curved (so that it rises a little from the surface where the electronic device is placed). Compared to the bottom surface of the lower section 27 being flat, this structure reinforces the lower section 27 against bending and twisting.
Also, as shown in FIG. 29 , a stopper 130 is provided on a periphery of each hinge h facing backward of the electronic device 1 . when the display 5 is opened, the display 5 is prevented from opening further by the lower edge of the display 5 meeting the stopper 130 . For example, in the present embodiment, the angle of opening (an angle formed by the body 3 and the display 5 ) is restricted to 135°.
Further, as shown in FIGS. 2 and 30 , tapered portions 68 and 69 are formed respectively at the front edges of the case 26 and the case 22 facing with each other so that the front edges make a V-shape when the display 5 is closed onto the body 3 .
The tapered portion 68 is inclined upward toward the front, and the tapered portion 69 is inclined downward toward the front. The distance between the tapered portions 68 and 69 in a closed state, namely, when the case 26 and the case 22 are closed, gradually increases toward the front.
With such a structure, even if the body 3 and the display 5 are very thin like the ones in the present embodiment, the front edge of the display 5 can easily be lifted from the body 3 staying where it is by putting a finger in a V-shaped area between the tapered portions 68 , and hooking the tapered portion 68 of the case 22 with a fingertip.
Further, as shown in FIGS. 1 and 2 , various indicator lamps 17 a - 17 c provided in the front edge of the body 3 extend to the downwardly inclined area of the front edge. Therefore, even when the display 5 is closed as in FIG. 2 , the above various indicator lamps 17 a - 17 c are visible to the user.
Although the invention has been described in its preferred form, it is to be understood that the invention is not limited to the specific embodiments thereof and various changes and modifications may be made without departing from the sprit and the scope of the invention.
Instead of the PC card slot of the body 3 , any other semiconductor-memory card slot may be provided.
Further, the heat-transmitting sheets 72 and 47 may be stuck to the inside of the upper section 28 and an entire surface of the inside of the lower section 27 , respectively.
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A power switch and connector that are conventionally included in a body are formed in spaces created at the outer ends of the shafts of hinges other than the body and a display, whereby the body is thinned. Electronic device comprises a body, a display, and a hinge that joins the body and display so that they can be freely opened or closed. A power switch is formed at an end of the shaft of the hinge. Furthermore, the electronic device comprises the body, the display, and another hinge that joins the body and display so that they can be freely opened or closed. A port of a connector opens at an end of the shaft of the hinge.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of application Ser. No. 11/586,001 filed on Oct. 25, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to novel diterpene compounds isolated from the fruiting body of Antrodia camphorata. The in vitro neuroprotective activity of the new compounds was evaluated to demonstrate their utility as a pharmaceutical agent.
BACKGROUND OF THE INVENTION
[0003] Antrodia camphorata Wu, Ryvarden & Chang (classified into Polyporaceae, Aphyllophorales) is a parasitic fungus on the endemic species Cinnamomum kanehirai Hay (Lauraceae), which is an endangered species in Taiwan. Because of its endemic unique and rare utility in pharmacology, A. camphorata possesses high values in commercial and research area, and therefore it is the rarest and most expensive wild fungus in Taiwan nowadays.
[0004] A. camphorata only grows on the inner heartwood wall of the stem of Cinnamomum kanehirai Hay (Lauraceae) of more than one hundred years old, or on the moist wood surface of dead cowcamphor trees in Taiwan mountain area of 450-2000 m above sea level. A. camphorata gows in a dark, moist and low-temperatured environment with a very slow growth rate. Thus, it takes a quite long time to produce fruiting body in the nature. Wild A. camphorata grows on old cowcamphor trees, producing its fruiting body from the inner wall of the hollow tree stem. The fruiting body of A. camphorata exhibits various morhphology, with shapes of sheet, bell, horseshoe, or tower. The color of new-born fruiting body is florid, then turns to white, pale sorrel, hazel, or tan at growing.
[0005] Traditionally, this fungus has been used as a Chinese remedy for food and drug intoxication, diarrhea, abdominal pain, hypertension, itching of the skin, and liver cancer (see, for example, Tsai, Z. T.; Liaw, S. L. The Use and the Effect of Ganoderma; Sang-Yun Press: Taichung, Taiwan, 1982; p 116). In current biological studies, the fruiting bodies exhibited immunomodulating, antioxidative, and hepatoprotective effects (Hsiao, G. et al., J. R. J. Agric. Food Chem. 2003, 51, 3302-3308). The cultured mycelia have shown to have anti-inflammatory activity, vasorelaxation, cytotoxic activity against several tumor cell lines, protective activity of oxidative damage in normal human erythrocytes, and anti-hepatitis B virus activity (see, for example, Liu, J. J. et al., Toxicol. Appl. Pharmacol. 2004, 201, 186-193; Hseu, Y. C. et al., Life Sci. 2002, 71, 469-482; and Lee, I. H. et al., FEMS Microbiol Lett. 2002, 209, 63-67).
[0006] There are many biologically active materials contained in A. camphorata , such as polysaccharides, triterpenoids, SOD (peroxidase), adenosine, small molecular proteins, vitamins, trace elements, nucleic acids, steroids, pressure stablizing agents and so on. The only chemical study of the cultured mycelia of A. camphorata was conducted by Nakamura et al., found five cytotoxic maleic and succinic acid derivates (Nakamura, N. et al., J. Nat. Prod. 2004, 67, 46-48). Previous chemical studies of the fruiting body of A. camphorata have led to reports of several components including fatty acids, lignans, phenyl derivatives, sesquiterpenes, steroids, and triterpenoids (see, for example, Chen, C. H.; Yang, S. W. J. Nat. Prod. 1995, 58, 1655-1661; Cherng, I. H.; Wu, D. P.; Chiang, H. C. Phytochemistry 1996, 41, 263-267; and Shen, C. C. et al., J. Chin. Med. 2003, 14, 247-258).
[0007] In the present invention, we report the isolation and structural elucidation of three new labdane diterpenoids (1-3) from the fruiting body of A. camphorata , that is 19-hydroxylabda-8(17)-en-16,15-olide (1), 3,β,19-dihydroxylabda-8(17),11E-dien-16,15-olide (2), and 13-epi-3β,19-dihydroxylabda-8(17),11E-dien-16,15-olide (3), together with four known compounds, 19-hydroxylabda-8(17),13-dien-16,15-olide (4), 14-deoxy-11,12-didehydroandrographolide (5), 14-deoxyandrographolide, and pinusolidic acid. The three novel compounds and four compounds of known structure were evaluated for their neuroprotective effects in an in vitro test system.
SUMMARY OF THE INVENTION
[0008] In a first aspect, the present invention provides novel diterpene compounds isolated from the fruiting body of Antrodia camphorate.
[0009] The present invention provides a novel compound of following formula 1:
[0000]
[0000] and a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof.
[0010] The present invention also provides a novel compound of following formula 2 or 3:
[0000]
[0000] wherein R is H,
and a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof.
[0011] In a second aspect, the present invention provides a pharmaceutical composition comprising at least one of the novel diterpene compounds disclosed in the invention, or a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof. In one embodiment of the invention, the present invention provides a pharmaceutical composition for the treatment, prophylaxis, and amelioration of neuron damages caused by drugs or aging, such as Alzheimer disease (AD, also known as a neurodegenerative disorder). In another embodiment, a composition of the invention comprises one or more prophylactic or therapeutic agents other than a compound of the invention, or a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof. In still another embodiment of the invention, the present composition comprises one or more the novel diterpene compounds disclosed in the invention, or a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof, combined with a pharmaceutically acceptable carrire, dilutant or excipient.
[0012] In a preferred embodiment, a composition of the invention is a pharmaceutical composition or as a single unit dosage form. Pharmaceutical compositions and dosage forms of the invention comprise one or more active ingredients in relative amounts and formulated in such a way that a given pharmaceutical composition or dosage form can be used to treat or prevent proliferative disease, such as cancer. The preferable pharmaceutical composition and dosage form contain a compound of formula 1, 2, 3, 4 or 5,14-deoxyandrographolide, or pinusolidic acid, or a pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent or derivative thereof, optionally combined with one or more additional active agents.
[0013] Other properties of the invention will be obvious after the detailed disclosure of following examples and appending drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows the Key NOESY correlation for 1.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The invention is further defined by reference to the following examples describing in detail the preparation of compounds of the invention. It will be apparent to those skilled in the art that many modifications, both to materials and methods, may be practiced without departing from the purpose and interest of this invention. The following examples are set forth to assist in understanding the invention and should not be construed as specifically limiting the invention described and claimed herein. Such variations of the invention, including the substitution of all equivalents now known or later developed, which would be within the purview of those skilled in the art, and changes in formulation or minor changes in experimental design, are to be considered to fall within the scope of the invention incorporated herein.
EXAMPLES
[0016] In the following examples, specific rotations were recorded on a JASCO DIP-1000 digital polarimeter. IR spectra were recorded on a Perkin-Elmer 983 G spectrometer. 1 H and 13 C NMR spectra were recorded on a Varian Unity Plus-400 spectrometer. EIMS and HREIMS were measured with a JEOL Finnigan TSQ-46C and JEOL SX-102A mass spectrometers. Extracts were chromatographed on silica gel (Merck 70-230 mesh, 230-400 mesh) and purified on a semi-preparative normal-phase HPLC column [250×10 mm, Licrosorb Si 60 (7 μm)] carried out with a LCD Refracto Monitor III. Significant peaks are tabulated in the order: δ (ppm): chemical shift, multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; br s, broad singlet), coupling constant(s) in Hertz (Hz) and number of protons.
Example 1
Isolation and Characterization of Compound 1-3
[0017] The fruiting bodies of A. camphorata (No. 2) were provided by Kang Jian Biotech Corp. Ltd., Nantau, Taiwan, Republic of China. The fungus was identified by Dr. Tun-Tschu Chang of the Division of Forest Protection, Taiwan Forest Research Institute. A voucher specimen (No. 35396) was deposited in the herbarium of Taiwan Forestry Research Institute, Taipei, Taiwan.
[0018] The dried fruiting bodies of A. camphorata (2 kg) were extracted with MeOH (40 L) at room temperature (5 days twice). After evaporation, the residue of the MeOH extract was mixed with H 2 O to bring the total volume to 1 L. This phase was extracted with 1 L of EtOAc (3 times), the combined organic phase was evaporated, and the obtained black syrup (150 g) was chromatographed on silica gel eluting with hexane and EtOAc solutions. The fraction eluted with 30-40% EtOAc in hexane was separated and purified by HPLC using a preparative silica gel column and a mixture of EtOAc/hexane (3:7) as eluent to give The EtOAc-soluble fraction, which was chromatographed repeatedly to afford three pure new compounds, compound 1 (8.2 mg, t R : 5′25″), compound 2 (19.4 mg, t R : 8′40″), and compound 3 (3.0 mg, t R : 8′45″); along with four known labdane diterpenoids, 19-hydroxylabda-8(17),13-dien-16,15-olide (compound 4, 32.4 mg, t R : 5′50″), 14-deoxy-11,12-didehydroandrographolide (compound 5, 5.5 mg, t R : 9′55″), 14-deoxyandrographolide (6.2 mg, t R : 9′10″), and pinusolidic acid (3.1 mg, t R : 11′25″). The structures of the known compounds were established by comparison of their spectroscopic data with literature values.
[0019] Compound 1 was isolated as an amorphous powder, and its molecular formula of C 20 H 32 O 3 was established through analysis of its 13 C NMR (shown in Table 1) and HREIMS data. The IR spectrum of 1 confirmed the presence of a γ-lactone group (1772 cm −1 ) and a hydroxyl group (3470 cm −1 ). The 1 H NMR spectrum (shown in Table 1) exhibited signals for two primary methyl groups [δ H 0.62 and 0.95 (3H each, s)], two methylene protons linked to a γ-lactone group [δ H 4.16 (td, J=8.8, 6.8 Hz) and 4.30 (td, J=8.8, 2.8 Hz)], a pair of olefinic protons [δ H 4.50 and 4.80 (1H each, br s)], two germinal carbinol protons [δ H 3.36 and 3.72 (1H each, d, J=11.2 Hz)]. The 1 H NMR data were almost same as those of known compound 4 except for that of H 2 -15 and one more olefinic proton for compound 4 (see, Han, B. H. et al., J. Med. Chem. 1998, 41, 2626-2630). The consecutive protons from δ H 1.0 to 2.0 were revealed from the COSY and the HMBC spectra and clarified their relative locations. The 13 C NMR data (shown in Table 1) and DEPT spectroscopic analysis showed 20 signals including two CH 3 , eleven CH 2 , three CH, three C and one lactone carbonyl carbon. The lactone carbonyl carbon was assigned to C-16 on the basis of the HMBC spectrum. The two methylene protons linked to the γ-lactone group were correlated to C-13 at δ C 39.5, C-14 at δ C 29.6, and C-16 at δ C 179.1. In the same experiment, interactions were evidenced between the H 2 -19 methylene protons at δ C 3.36 and 3.72 with the carbons C-3 at δ 35.4, C-4 at δ 39.6, C-5 at δ 57.1, and C-18 at δ 27.1. The NOESY spectrum (shown in FIG. 1 ) confirmed that the C-20 methyl group, H 2 -11, and H 2 -19 are on the same side of the molecule. The C-13 stereochemistry is uncertain. Based on the above evidence, the structure of compound 1 was proposed as 19-hydroxylabda-8(17)-en-16,15-olide.
[0020] Compound 2 was isolated as an amorphous powder. The molecular formula of C 20 H 30 O 4 was determined on the basis of HREIMS and 13 C NMR data (shown in Table 1). The IR absorption bands at 3381 cm −1 and 1777 cm −1 indicated the presence of hydroxyl and γ-lactone functionalities. The 1 H NMR spectrum (shown in Table 1) exhibited signals for two primary methyl groups [δ H 0.72 and 1.22 (3H each, s)], and two methylene protons linked to a r-lactone group [δ H 4.23 (td, J=8.4, 6.8 Hz), δ H 4.34 (td, J=8.4, 3.6 Hz)], a pair of terminal methylene protons [δ H 4.50 and 4.74 (1H each, d, J=1.6 Hz)], a pair of trans-coupling olefinic protons [δ H 5.50 (dd, J=15.6, 5.6 Hz) and 5.64 (dd, J=15.6, 9.6 Hz)], a carbinol proton [δ H 3.45 (dd, J=11.2, 4.4 Hz)], and two germinal carbinol protons [δ H 3.30 and 4.17 (1H each, d, J=11.2 Hz)]. The signals of the other methylene protons in the 1 H NMR spectrum were similar to those of 5 (Reddy, M. K. et al., Phytochemistry 2003, 62, 1271-1275). Compound 5 has one more double bond and, therefore, one more olefinic signal than 2 in the 1 H NMR spectrum. The 1 H chemical shifts of H-11 and H-12 in 2 shift to higher field comparing to those of compound 5, and meanwhile compound 2 has no significant absorption in its UV spectrum. In the HMBC spectrum, the signal of H-3 (δ H 3.45) was correlated with C-18 and C-19, indicated that the hydroxyl group is linked at C-3. The H-3 proton was assigned as axially oriented according to its observed coupling constants (J=11.2, 4.4 Hz). In the NOESY spectrum, the proton signal of H-20 showed correlations with H-11 and H-19, suggesting that H-11, H-19 and H-20 were all β-oriented. The C-13 stereochemistry is uncertain. Based on the above evidence, compound 2 was proposed as 3β,19-dihydroxylabda-8(17), 11E-dien-16,15-olide.
[0021] Compound 3 was also isolated as an amorphous powder and assigned a molecular formula of C 20 H 30 O 4 from HREIMS and 13 C NMR data. The IR absorption bands at 3391 and 1775 cm −1 confirmed the presence of hydroxyl groups and a γ-lactone group. As a result of the assignment of the HMBC and HMQC spectra, the gross structure of compound 3 was shown to be the same as that of compound 2. From the analysis of NOESY spectrum, the relative configuration of the molecule and the side chain at C-9 was assigned as the same as compound 2. Analysis of all the data obtained suggested that compound 3 is the 13-epimer of 2 and proposed as 13-epi-3β,19-dihydroxylabda-8(17), 11E-dien-16,15-olide.
[0000]
TABLE 1
NMR Data (CDCl 3 , 400 MHz) for Compounds 1-3 [δ in ppm, mult. (J in Hz)]
1
2
3
position
δ C a
δ H
δ C a
δ H
δ C a
δ H
1
39.0
t
1.05 td (13.2, 5.2)
38.2
t
1.10 td (14.0, 4.4)
38.3
t
1.12 td (13.2, 4.8)
1.45 dt (14.0, 3.6)
1.60 dt (13.2, 4.0)
1.58 m
2
19.0
t
1.56 m
23.0
t
1.75 m
23.3
t
1.80 m
1.82 m
1.29 m
1.29 m
3
35.4
t
1.31 m
80.7
d
3.45 dd (11.2, 4.4)
80.8
d
3.46 dd (11.2, 5.2)
1.89 m
4
39.6
s
42.9
s
43.2
s
5
57.1
d
1.22 dd (12.8, 2.4)
54.6
d
1.15 dd (12.8, 2.0)
54.8
d
1.16 dd (12.8, 2.4)
6
24.4
t
1.77 m
28.2
t
1.70 m
28.5
t
1.71 m
1.79 m
1.72 m
1.73 m
7
38.5
t
1.98 m
36.5
t
2.00 td (12.8, 4.8)
36.8
t
2.00 td (13.2, 4.4)
2.37 m
2.40 br d (12.8)
2.41 br d (12.4)
8
147.4
s
148.1
s
148.0
s
9
56.3
d
2.34 m
60.4
d
2.26 d (9.6)
60.5
d
2.26 d (10.0)
10
38.9
s
38.1
s
38.5
s
11
21.4
t
1.42 m
131.5
d
5.64 dd (15.6, 9.6)
131.9
d
5.67 ddd (15.2, 10.0, 1.2)
1.50 m
12
28.9
t
1.24 m
127.1
d
5.50 dd (15.6, 5.6)
127.0
d
5.44 dd (15.2, 6.8)
1.46 m
13
39.5
d
2.46 m
42.2
d
3.24 m
42.9
d
3.25 m
14
29.6
t
1.75 m
29.1
t
2.45 m
29.7
t
2.46 m
1.96 m
2.15 m
2.14 m
15
66.4
t
4.16 td (8.8, 6.8)
66.5
t
4.34 td (8.4, 3.6)
66.6
t
4.35 td (9.2, 4.0)
4.30 td (8.8, 2.8)
4.23 td (8.4, 6.8)
4.23 td (9.2, 6.8)
16
179.1
s
177.1
s
176.6
s
17
106.7
t
4.50 br s
108.8
t
4.74 d (1.6)
108.2
t
4.74 d (1.6)
4.80 br s
4.50 d (1.6)
4.45 d (1.6)
18
27.1
q
0.95 s
22.7
q
1.22 s
23.0
q
1.23 s
19
64.9
t
3.36 d (11.2)
64.1
t
4.17 d (11.2)
64.2
t
4.18 d (11.2)
3.72 d (11.2)
3.30 d (11.2)
3.31 d (11.2)
20
15.3
q
0.62 s
15.9
q
0.72 s
16.2
q
0.72 s
a Multiplicities were obtained from DEPT experiments.
Example 2
The Effects of Isolated Pure Compounds on Protection Neurons from Damage
[0022] In this study, primary cultures of neonatal cortical neurons from the cerebral cortex of Harlan Sprague-Dawley rat pups at postnatal day were used as target cells. Primary cultures of neonatal cortical neurons were prepared from the cerebral cortex of Harlan Sprague-Dawley rat pups at postnatal day 1. Briefly, each pup was decapitated and the cortex was digested in 0.5 mg/mL papain at 37° C. for 15 min. The tissue was dissociated in Hibernate A medium (containing B27 supplement) by aspirating trituration to separate cells. Cells were plated (at the density of 5×10 4 cells/cm 2 ) onto poly-D-lysine-coated dishes and maintained in Neurobasal medium containing B27 supplement, 10 units/mL penicillin, 10 mg/mL streptomycin, and 0.5 mg/mL glutamine (5% CO 2 /9% O 2 ) for 3 days. Cells were then exposed to cytosine-β-D-arabinofuranoside (5 μM) for 1 day to inhibit proliferation of non-neuronal cells. The cells were used for the experiment on the fifth day.
[0023] The effects of isolated pure compounds on Aβ 25-35 -treated cell apoptosis were determined by a MTT method for evaluating neuroprotective activity. The mitochondrial dehydrogenase activity was assayed by reduction cleavage of the tetrazolium salt MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide), to yield a purple dye with absorbance read at about 570 nm. Results are expressed as percentage of control absorbance. Cortical neurons prepared as described above were incubated with vehicle (0.1% DMSO) or various concentrations of the compounds for 2 h then exposed to 5 μM Aβ for 40 h. The cell viability was assessed by MTT reduction analysis. Cells were incubated with minimum essential medium containing 0.5 mg/mL MTT for 1 h. The medium was aspirated, and the formazan particle was dissolved with DMSO. The absorbance at 600 nm was measured using an enzyme-linked immunosorbent assay reader. Results are expressed as means±S.D. and were analyzed by ANOVA with post hoc multiple comparison with a Bonferroni test.
[0024] As the results showed in Table 2, the compounds 1-5 reduced Aβ-induced neurotoxicity in a concentration-dependent manner. The compounds significantly protected neurons from Aβ damage by 25.3% (compound 1), 29.5% (compound 2), 36.7% (compound 3), 28.9% (compound 4), and 29.5% (compound 5), at concentrations of 5, 10, 10, 10, and 20 μM, respectively.
[0000]
TABLE 2
Protection of Cortical Neurons against Aβ-Induced Cell Death by
Selected Compounds from the Fruiting Body of Antrodia camphorata a
5 μM Aβ plus
concentration
reagent
(μM)
cell death (%)
1
1
34.4 ± 3.4
5
25.3 ± 5.7***
10
28.1 ± 5.7***
20
30.8 ± 5.0**
2
1
43.8 ± 9.5
5
34.9 ± 2.6
10
29.5 ± 6.4*
20
26.3 ± 9.4**
3
1
45.1 ± 3.5
5
39.6 ± 3.4
10
36.7 ± 8.7
20
29.3 ± 10.6**
4
1
41.2 ± 3.4
5
34.8 ± 3.2
10
28.9 ± 8.1**
20
32.6 ± 7.2*
5
1
40.7 ± 3.3
5
35.7 ± 1.9
10
30.8 ± 5.7***
20
29.5 ± 5.0***
Ac-DEVD-CHO
1
35.8 ± 3.5
5
30.2 ± 5.5***
10
24.5 ± 4.6***
20
23.1 ± 1.6***
Vehicle (0.1% DMSO)
40.5 ± 1.4
a Cortical neurons were incubated with vehicle (0.1% DMSO), Ac-DEVD-CHO (caspase 3 inhibitor for the positive control) or compounds from Antrodia camphorata at the indicated concentration for 2 h, then exposed to 5 μM Aβ 25-35 for 40 h. The cell viability was assessed by MTT reduction analysis. The data are means ± S.D of three independent experiments. Significant differences of cell death between cells treated with Aβ and Aβ plus compound are indicated by
*p < 0.05;
**p < 0.01; and
***p < 0.001.
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The present invention relates to novel diterpene compounds isolated from the fruiting body of Antrodia camphorate , especially to the new compounds of following structural formula:
and pharmaceutically acceptable salt, solvate, hydrate or biologically active equivalent thereof. The present invention also relates to a pharmaceutical composition containing at least one of the novel diterpene compounds, and a use of the diterpene compound as a neuroprotective agent.
| 2
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FIELD OF THE INVENTION
[0001] The present invention relates to computer enclosures, and more particularly to a computer enclosure with a bracket for data storage devices.
DESCRIPTION OF RELATED ART
[0002] Usually, a bracket is fixed to a computer enclosure for securing storage devices. The bracket is generally installed on an inner surface of the computer enclosure.
[0003] For example, the computer enclosure generally includes a front panel. The front panel defines an opening therein. The bracket is installed on an inner surface of the front panel. The data storage devices are installed into the bracket through the opening of the front panel. However, in this computer enclosure, the bracket usually takes up a fairly large amount of space.
[0004] What is needed, therefore, is a computer enclosure with a bracket for improving usage of limited space of the computer enclosure.
SUMMARY OF THE INVENTION
[0005] A computer enclosure includes a front panel and a bracket configured for receiving data storage devices therein. The bracket is accommodated in the computer enclosure. An opening is defined at the front panel for exposing the bracket. The bracket has a side wall covering the opening. A locking plate is pivotably attached to the bracket and locked with the front panel to thereby locking the bracket to the computer enclosure.
[0006] Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an exploded isometric view of a computer enclosure of a preferred embodiment of the present invention, the computer enclosure including a front panel, a bottom panel, a bracket, and a locking plate;
[0008] FIG. 2 is similar to FIG. 1 , showing the bracket installed in the computer enclosure;
[0009] FIG. 3 is an assembled view of FIG. 1 , including two data storage devices in the bracket, and the locking plate in an unlocked position;
[0010] FIG. 4 is similar to FIG. 3 , but showing the locking plate in a locked position; and
[0011] FIG. 5 is similar to FIG. 4 , but viewed from another aspect.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Referring to FIG. 1 , a computer enclosure includes a front panel 10 , a bottom panel 30 , and a bracket 50 .
[0013] A rectangular opening 13 is defined in a bottom of the front panel 10 . A first flange 131 and a second flange 133 extend out from top and bottom edges of the opening 13 of the front panel 10 respectively. A third flange 135 extends out from a side edge of the front panel 10 . The flanges 131 , 133 , 135 are perpendicular to the front panel 10 . A fourth flange 15 extends inward from a side edge of the front panel 10 . The fourth flange 15 is parallel to the third flange 135 . Each of the flanges 131 , 133 , 135 , 15 has a plurality of anti-EMI (electronic magnetic interference) clips 16 . A first positioning hole 171 is defined in the front panel 10 above the first flange 131 far away from the third flange 135 on the front panel 10 . A second positioning hole 173 is defined in the front panel 10 underneath the second flange 133 far away from the third flange 135 . The front panel 10 defines two holes 19 above the first flange 131 , and the bottom panel 30 defines two holes 39 therein.
[0014] The bracket 50 includes a top wall 56 , a bottom wall 58 , a first side wall 52 , a second side wall 54 , and a locking plate 51 . The top wall 56 , the bottom wall 58 , and the side walls 52 , 54 together form a space for accommodating data storage devices 90 (shown in FIGS. 3-5 ) therein. An entrance, through which the data storage devices 90 can enter into the bracket 50 , is formed at one side of the bracket 50 and surrounded by the top wall 56 , the bottom wall 58 , and the side walls 52 , 54 . The first side wall 52 defines two pivot holes 521 , 523 . Two mounting plates 53 are defined at the top wall 56 of the bracket 50 . Each mounting plate 53 defines a mounting hole 531 corresponding to one of the holes 19 defined in the front panel 10 . An L-shaped supporting plate 55 with two mounting holes 551 (only one shown in FIG. 1 ) is formed on the bottom wall 58 of the bracket 50 , corresponding to the holes 39 of the bottom panel 30 . The bracket 50 has a plurality of clips 57 for securing the data storage devices 90 . A plurality of holes 59 is defined in the first side wall 52 of the bracket 50 . The locking plate 51 has two pivots 511 , 513 for being inserted into the pivot holes 521 , 523 of the bracket 50 . A first finger 515 with a first protrusion 5151 extends from the middle of the top edge of the locking plate 51 , and a second finger 517 with a second protrusion 5171 extends from the middle of the bottom edge of the locking plate 51 . The locking plate 51 has a block flange 519 . The block flange 519 has a protuberance 5191 and a plurality of EMI clips 5193 .
[0015] Referring also to FIGS. 2 and 3 , in assembly, the bracket 50 is received in the computer enclosure. The first side wall 52 of the bracket 50 extends out of the opening 13 of the front panel 10 . The first and second flanges 131 , 133 of the computer enclosure 30 abut against the top and bottom walls 56 , 58 of the bracket respectively. The third flange 135 abuts against the bracket 50 at a location far away from the entrance. The forth flange 15 abuts against the bracket 50 at the entrance. The mounting plates 53 of the bracket 50 abut against an inner surface of the front panel 10 , and the mounting holes 531 of the mounting plates 53 align with the respective holes 19 of the front panel 10 . Two stakes (not shown) are inserted through the holes 19 , 531 to fix the bracket 50 to the front panel 10 . The mounting holes 551 of the bracket 50 align with the holes 39 of the bottom panel 30 . Another stake (not shown) is inserted through the holes 39 , 551 to secure the bracket 50 on the bottom panel 30 . The bracket 50 is therefore locked in the computer enclosure. The pivots 511 , 513 of the locking plate 51 are respectively engaged into the pivot holes 521 , 523 of the bracket 50 . Consequently, the locking plate 51 is pivotally attached on the bracket 50 , and extends out of the computer enclosure.
[0016] Referring also to FIGS. 3 to 5 , the data storage devices 90 are installed into the bracket 50 . Screws 60 are engaged into the holes 59 of the bracket 50 to lock the data storage devices 90 in the bracket 50 . The locking plate 51 is rotated in. The first finger 515 and the second finger 517 are wedged into the first positioning hole 171 and the second positioning hole 173 of the front panel 10 respectively. The first protrusion 5151 of the first finger 515 and the second protrusion 5171 of the second finger 517 are against edges of the first positioning hole 171 and the second positioning hole 173 respectively. Meanwhile, the flange 519 of the locking plate 51 is substantially coplanar with the fourth flange 15 of the front panel 10 , and the protuberance 5191 of the flange 519 resiliently engages the data storage devices 90 .
[0017] It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of a preferred embodiments, together with details of the structure and function of the preferred embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
|
A computer enclosure includes a front panel and a bracket configured for receiving data storage devices therein. The bracket is accommodated in the computer enclosure. An opening is defined at the front panel for exposing the bracket. The bracket has a side wall covering the opening. A locking plate is pivotably attached to the bracket and locked with the front panel to thereby locking the bracket to the computer enclosure.
| 6
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FIELD OF THE INVENTION
This invention relates to a method for the production of a thin oxide superconducting film and to a Sr--La--Ga type oxide single crystal usable advantageously as a substrate for the production mentioned above.
BACKGROUND OF THE INVENTION
The electronic devices utilizing the phenomenon of superconduction find extensive utility in various applications as high-speed switches, high-sensitivity detectors, and high-sensitivity fluxmeters.
These superconducting devices are constructed with thin superconducting films. Since the thin superconducting films have considerably low critical superconducting temperatures (Tc) and, therefore, require use of liquefied helium as a cooling agent, they have encountered the problem of high cost, complexity of overall system, and incapability of size reduction.
Thus, studies have been promoted on thin oxide superconducting films possessing high critical superconducting temperatures. Thin oxide superconducting films discovered in recent years have critical superconducting temperatures exceeding 77° K. and, therefore, are capable of being operated by the use of inexpensive liquefied nitrogen as a cooling agent.
For the production of thin oxide films of this class, the method which comprises superposing a given thin film by the spattering method or the vacuum evaporation method on a MgO single-crystal substrate or a SrTiO 3 single-crystal substrate heated in advance to an elevated temperature has been used. It has been proposed in recent years for the purpose of enhancing the epitaxial growth of a thin oxide film to use as a substrate therefor an oxide insulator possessing a lattice-matching property relative to a given oxide superconductor and, at the same time, containing at least one of the component elements of the superconductor (Japanese Patent Application Disclosure SHO 63(1988)-236,794).
The conventional method for the production of a thin film by the use of a MgO single crystal or a SrTiO 3 single crystal as a substrate does not easily produce an epitaxial film of high quality. This fact has posed itself a serious problem for the stabilization of critical superconducting temperature (Tc) and for the improvement and stabilization of the critical superconducting current (Jc).
To allow the growth of an excellent epitaxial film, the material for the substrate must fulfil the following requirements, for example:
(i) It should exhibit a highly satisfactory lattice-matching property to a thin crystal film.
(ii) It should avoid deteriorating film quality due to mutual diffusion of the film and the substrate during the epitaxial growth of the film.
(iii) It should possess a high melting point exceeding at least 1,000° C. to withstand the heating at an elevated temperature.
(iv) It should be procurable in the form of a single crystal possessing highly satisfactory crystallinity.
(v) It should be an insulator of electricity.
Incidentally, numerous oxides such as those of the InBa 2 Cu 2 O 7- δ (δ=0 to 1, Ln=Yb, Er, Y, Ho, or Gd) type, the Bi--Sr--Ca--Cu--O type, and the Tl--Ba--Ca--Cu--O type, for example, have been reported as high-temperature oxide superconductors. The lattice constants, a and b, of these oxide superconductors are invariably in the range of 3.76 to 3.92 Å.
Since they assume a face-centered configuration, the magnitudes √2a and √2b may well be regarded as representing the basic lattices. In this case, the lattice constants, a and b, are expressed as 5.32 to 5.54 Å.
In contrast, MgO which is a material now in widespread use for substrates has a lattice constant, a=4.203 Å, and a lattice mismatch ratio as high as to reach a range of 7 to 11%. Thus, it allows production of an epitaxial film of good quality only with difficulty.
SrTiO 2 possesses a small lattice mismatch ratio in the range of 0.4 to 4% and exhibits an excellent lattice-matching property. The SrTiO 3 single crystal, however, is produced at present solely by the Bernoulli method. The crystal obtained by this method exhibits very poor crystallinity and possesses an etch pit density exceeding 10 4 pits/cm 2 . It allows production of an epitaxial film of high quality only with difficulty. Further, substrates of an appreciably large size are not procurable.
SUMMARY OF THE INVENTION
This invention, produced in the urge to eliminate the drawbacks of the prior art described above, aims to provide a novel single-crystal substrate material capable of readily forming an epitaxial film of good quality.
Another object of this invention is to provide a method capable of producing a thin oxide superconducting film excelling in crystal-linity and possessing high quality.
To accomplish the objects described above in accordance with the first aspect of the present invention, there is provided a Sr--La--Ga type oxide single crystal possessing a crystal structure of the K 2 NiF 4 type and having a composition of Sr 1-X La 1-Y Ga 1-Z O 4-W (-0.1<X<0.1, -0.1<Y<0.1, -0.1<Z<0.1, -0.4<W<0.4), and befitting a substrate material.
Then, according to the second aspect of the present invention, there is provided a method for the production of a thin oxide superconduting film,characterized by using as a substrate the aforementioned SrLaGaO 4 single crystal which is a high-melting oxide possessing a lattice constant closely approximating that of a pertinent oxide superconductor and effecting epitaxial growth of a thin oxide superconducting film on the substrate.
As described above, the SrLaGaO 4 single crystal according with the present invention is an oxide insulator which possesses a lattice constant falling in the range in which the lattice constants of oxide superconductors possessing high critical superconducting temperatures fall, also possesses a crystal structure closely approximating those of the oxide superconductors, and exhibits a highly satisfactory lattice-matching property. In accordance with this invention, therefore, a thin superconducting oxide film possessing high magnitudes of Tc and Jc can be produced because epitaxial growth of a thin oxide superconducting film can be attained by using as a substrate therefor the aforementioned SrLaGaO 4 single crystal.
These and other objects, aspects, and advantages of the present invention will become apparent to persons skilled in the art as the disclosure is made in the following description of preferred embodiments cited as examples conforming to the principle of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The high-temperature oxide superconductors reported to date have lattice constants, a and b, in the range of 3.76 to 3.92 Å as already mentioned. The present inventor has continued a study in search of a substrate grade single crystal possessing a lattice constant of 3.85 Å, a mean value of the range just mentioned. He has consequently found that in the various crystals possessing the lattice constant, a=3.85 Å, SrLaGaO 4 can constitute itself an outstanding material for a substrate.
It has been reported by G. Blasse (J. Inorg. Nucl. Chem., (1965), Vol. 27, pp. 2683-2684) that SrLaGaO 4 assumes a K 2 NiF 4 type structure and possesses a lattice constant, a=3.84 Å. What was produced by G. Blasse was a sintered mass and not a single crystal. K. Aso produced a sintered mass of SrKaGaO 4 and tested it to determine its lattice constant (J. Phys. Soc. Jpn., (1978), Vol. 44, No. 4, pp. 1083 to 1090). These two reports are the only information published so far concerning the compound SrLaGaO 4 . The products covered thereby are invariably sintered masses and not single crystals. For use as a substrate intended for the production of an epitaxially grown film, a sintered mass which is a polycrystal is undesirable. The substrate should be a single crystal. Neither the feasibility of the production of a single crystal of SrLaGaO 4 nor the melting point of this oxide is reported anywhere in the literature published to date.
The present inventor, therefore, conducted a study on the transformation of SrLaGaO 4 into a single crystal and tried the production of the single crystal by the crucible cooling method. As regards synthesis of a raw material, a sintered mass of SrLaGaO 4 was obtained by mixing SrCO 3 , La 2 O 3 , and Ga 2 O 3 in a molar ratio of 2:1:1 calcining the resultant mixed powder at 1,200° C. pulverizing and then pressing the calcined powder, and sintering the pressed mass of the powder. This sintered mass was placed in a platinum crucible, heated to a level exceeding the melting point, and then gradually cooled at a rate of 1° C./min. As the result, a large planar single crystal measuring the square of 5 to 15 mm and having the plate surface as a C plane was easily obtained. This single crystal had a melting point of about 1,520° C., indicating that it was a sufficiently high-melting crystal.
The composition capable of forming a single crystal was confirmed to be in the following range: Sr 1-X La 1-Y Ga 1-Z O 4-W' wherein -0.1<X<0.1, -0.1<Y<0.1, -0.1<Z<0.1, and -0.4<W<0.4.
The inventor tried the production of the single crystal by the Czokralsky method. Specifically, a single crystal of a [001] axis measuring 25 mm in diameter and 100 mm in length was obtained in a 1 vol % O 2 --N 2 atmosphere at a pulling speed in the range of 2 to 6 mm/hr and a crystal revolution umber in the range of 10 to 60 rpm.
The single crystal of SrLaGaO 4 can be produced by the crucible cooling method and the Czokralski method as described above. Otherwise, it may be produced by the zone melting method and the Bridgman method as well.
The single crystal of SrLaGaO 4 has a lattice constant, a=3.84 Å. Since it is a face-centered tetragonal crystal, it may be regarded as having √2a as a basic lattice and, therefore, possessing a lattice constant, a=5.43 Å. Since the lattice constants, a and b, of the oxide superconductors fall in the range of 3.76 to 3.92 Å or in the range of 5.32 to 5.54 Å as described above, their lattice mismatch ratios relative to the SrLaGaO 4 are invariably so small as to fall within ±2%. The single crystal possesses a crystal structure closely approximating those of the oxide superconductors and exhibits an outstanding lattice-matching property.
As the result, by using a substrate of SrLaGaO 4 and superposing thereon by epitaxial growth a thin oxide superconducting film by the spattering method, the vacuum evaporation method, etc., a thin oxide superconducting film possessing highly satisfactory crystal-linity can be easily obtained.
EXAMPLES
Now, the present invention will be described more specifically below with reference to working examples. Of course, this invention is not limited to these examples.
EXAMPLE 1
This example concerns production of a Sr--La--Ga type oxide single crystal.
To obtain a single crystal of the composition of SrLaGaO 4 , 678.3 g of La 2 O 3 (purity 99.99%), 614.7 g of SrCO 3 (purity 99.999%), and 390.2 g of Ga 2 O 3 (purity 99.999%) were mixed and the resultant mixture was calcined at 1,200° C. for decarbonation, then pulverized, and press molded. A sintered mass of SrLaGaO 4 weighing approximately 1,500 g was obtained by sintering the molded mass in the open air at 1,300° C.
This sintered mass was placed in an iridium crucible measuring 800 mm in outside diameter, 80 mm in height, and 2 mm in wall thickness and then liquefied by high-frequency heating therein. A nitrogen atmosphere containing 0.5 to 2% of oxygen was used to envelope the site of the heat treatment. Since vaporization of a small portion of the gallium oxide occurred under a nitrogen atmosphere containing no oxygen, the addition of oxygen in the amount indicated above was found to be desirable.
After the content of the crucible was fused, a seed crystal was immersed in the melt and processed in accordance with the Czokralski method to induce growth of a single crystal of SrLaGaO 4 .
Initially, a [100] single crystal of SrTiO 3 was used as the seed crystal. After the single crystal of SrLaGaO 4 was obtained, the single crystal in the [001] orientation of the produced crystal was used as a seed crystal. The crystal was pulled at a pulling rate of 5 mm/hr and a crystal rotating speed of 30 rpm. Under these conditions, a [001] axis single crystal measuring 25 mm in diameter and 100 mm in length was obtained.
It was confirmed that a single crystal of high quality could be produced so long as the composition was in the following range: Sr 1-X La 1-Y Ga 1-Z O 4-W' wherein -0.1<X<0.1, -0.1<Y<0.1, -0.1<Z<0.1, and -0.4<W 0.4.
EXAMPLE 2
A (001) plane single crystal of SrLaGaO 4 and a (100) plane single crystal of SrTiO 3 for comparison were used. On these substrates, a thin oxide film was superposed in a thickness of 1,000 Å by the RF magnetron spattring using a target of YBa 2 Cu 3 O 7- δ under an atmosphere of Ar/O 2 (mixing ratio 1:1). The conditions for the spattering were 10 Pa of gas pressure, 300 W of electric power, and 600° C. of substrate temperature. After the superposition, the thin oxide films produced were annealed under an O 2 atmosphere at 900° C. for 1 hour.
By the four-terminal method, the produced thin films were tested for zero resistance temperature Tco and critical superconducting current Jc at 77° K. The results are shown in Table 1.
TABLE 1______________________________________Tco and Jc of YBa.sub.2 Cu.sub.3 O.sub.7-δMaterial of substrate Tco (K.) Jc (A/cm.sup.2) at 77° K.______________________________________Conventional method (SrTiO.sub.3) 79 0.5 × 10.sup.4This invention (SrLaGaO.sub.4) 84 1 × 10.sup.5______________________________________
It is clearly noted from the results given above that the product obtained by using the single crystal of SrLaGaO 4 as a substrate excelled both in Tco and Jc the product obtained by using the SrTiO 3 as a substrate. This fact may be logically explained by a postulate that the film produced with the SrLaGaO 4 substrate excelled crystallinity and uniformity and, therefore, enjoyed improvement in Tco and Jc.
When the surfaces of the produced thin films were examined by reflection high-speed electron diffraction (RHEED) as to crystal-linity, it was found that the thin film formed on the SrLaGaO 4 substrate showed a sharp spot-like diffraction pattern representing a (001) orientation, indicating that it was a (001) single crystal and produced epitaxial growth.
When thin oxide films were formed each on the (001) plane single crystal as a substrate under the same conditions as described above, excepting LnBa 2 Cu 3 O 7- δ (Ln=Yb, Er, Ho, or Gd) was used as a target material, it was found that the produced films invariably produced epitaxial growth.
EXAMPLE 3
A (001) plane single crystal of SrLaGaO 4 and a (100) plane single crystal of SrTiO 3 for comparison were used. On these substrates, a thin oxide film was superposed in a thickness of 1,000 Å by the RF magnetron spattering using a target of Bi 4 Sr 2 Ca 3 Cu 4 O under an atmosphere of Ar/O 2 (mixing ratio of 2:1). The conditions for the spattering were 5 Pa of gas pressure, 200 W of electric power, and 600° C. of substrate temperature. After the superposition, the thin oxide films produced were annealed under an O 2 atmosphere at 900° C. for 1 hour.
By the four-terminal method, the produced thin films were tested for zero resistance temperature Tco and critical superconducting current Jc at 77° C. The results are shown in Table 2.
TABLE 2______________________________________Tco and Jc of thin BiSrCaCuO filmMaterial of substrate Tco (K.) Jc (A/cm.sup.2) at 77° K.______________________________________Conventional method (SrTiO.sub.3) 90 1.5 × 10.sup.4This invention (SrLaGaO.sub.4) 105 2 × 10.sup.6______________________________________
It is clearly noted from the results given above that on the SrLaGaO 4 substrate, better Tco and Jc were obtained presumably because the film formed thereon excelled in both crystallinity and uniformity.
EXAMPLE 4
A (001) plane single crystal of SrLaGaO 4 and a (100) plane single crystal of SrTiO 3 for comparison were used. On these substrates, a thin oxide film was superposed in a thickness of 1,000 Å by the RF magnetron spattering using a target of Tl 2 Ba 2 Ca 2 Cu 3 O X under an atmosphere of Ar/O 2 (mixing ratio 1:1). The conditions for the spattering were 10 Pa of gas pressure, 80 W of electric power, and 600° C. of substrate temperature. After the superposition, the thin oxide films produced were wrapped in gold foil and annealed under an O 2 atmosphere at 905° C. for 10 minutes.
By the four-terminal method, the produced films were tested for Tco and Jc at 77° K. The results are shown in Table 3.
TABLE 3______________________________________Tco and Jc of thin TlBaCaCuO filmMaterial of substrate Tco (K.) Jc (A/cm.sup.2) at 77° K.______________________________________Conventional method (SrTiO.sub.3) 92 0.5 × 10.sup.4This invention (SrLaGaO.sub.4) 107 5 × 10.sup.5______________________________________
It is clearly noted from the results given above that, on the SrLaGaO 4 substrate, better Tco and Jc were obtained presumably because the film formed thereon excelled in crsytallinity and uniformity.
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A method for producing a thin oxide superconducting film possessing high crystallinity and excellent quality and a novel single crystal as a substrate allowing easy formation of an epitaxial film of high quality usable for the method are provided. The method for the production of the thin oxide superconducting film is characterized by using as a substrate a single crystal of SrLaGaO 4 which is a high-melting oxide and effecting epitaxial growth of a thin oxide superconducting film on the substrate. The single crystal used as a substrate is an oxide single crystal possessing a crystal structure of the K 2 NiF 4 type and having a composition of Sr 1-X La 1-Y Ga 1-Z O 4-W (wherein X, Y, Z, and W fall in the following respective ranges; -0.1<X<0.1, -0.1<Y<0.1, -0.1<Z<0.1, and -0.4<W<0.4).
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a cryostat, in particular for use in a magnetic resonance imaging (MRI) system. Furthermore, the invention relates to a method for reducing heat input into a cryostat.
[0003] 2. Description of the Prior Art
[0004] Superconducting magnet systems are used for medical diagnosis, for example in magnetic resonance imaging systems. A requirement of an MRI magnet is that it produces a stable, homogeneous, magnetic field. In order to achieve the required stability, it is common to use a superconducting magnet system which operates at very low temperature. The temperature is typically maintained by cooling the superconductor by immersion in a low temperature cryogenic fluid, also known as a cryogen, such as liquid helium.
[0005] The superconducting magnet system typically comprises a set of superconductor windings for producing a magnetic field, the windings being immersed in a cryogenic fluid to keep the windings at or below the superconducting temperature, the superconductor windings and the cryogen being contained within a cryogen vessel. The cryogen vessel is typically surrounded by one or more thermal shields, and a vacuum jacket completely enclosing the shield(s) and the cryogen vessel.
[0006] An access neck typically passes through the vacuum jacket from the exterior, into the cryogen vessel. Such access neck is used for filling the cryogen vessel with cryogenic fluids and for passing services into the cryogen vessel to ensure correct operation of the magnet system.
[0007] Cryogenic fluids, and particularly helium, are expensive and it is desirable that the magnet system should be designed and operated in a manner to reduce to a minimum the amount of cryogen consumed. Heat leaks into the cryogen vessel will evaporate the cryogen, which might then be lost from the magnet system as boil-off. In order to reduce the heat leaking into the cryogen vessel, and thus the loss of liquid, it is common practice to use a refrigerator to cool the thermal shields to a low temperature.
[0008] It is desirable that such superconducting magnet systems should be transported from the manufacturing site to the operational site containing the cryogen, so that they can be made operational as quickly as possible. In the case when the cryogen has been depleted, the system begins to warm-up and, if it exceeds a critical temperature, the magnet has to be pre-cooled with liquid nitrogen and then re-filled with the cryogen which is a time consuming and expensive process.
[0009] During transportation of an already assembled system, the refrigerator provided to cool the one or more shields and/or the cryogen vessel is inactive, and is incapable of removing the heat load from the shield and/or the cryogen vessel. Indeed, the refrigerator itself provides a low thermal resistance path for ambient heat to reach the cryogen vessel and shield(s). This in turn means a relatively high level of heat input during transportation, leading to loss of cryogen liquid by boil-off to the atmosphere.
[0010] It is desirable to reduce the loss of cryogen to the minimum possible, both since cryogens are costly and in order to prolong the time available for delivery, also known as the hold time, the time during which the system can remain with the refrigerator inoperable, but still contain some cryogen.
[0011] It is well known that the cold gas from evaporating cryogenic fluids can be employed to reduce heat input to cryogen vessels, by using the cooling power of the gas to cool the access neck of the cryogen vessel and to provide cooling to thermal shields by heat exchange with the cold exhausting gas.
[0012] Further, it has been demonstrated that removing the refrigerator and replacing the refrigerator with a heat exchanger can noticeably reduce the heat load onto the internal parts of the system, and therefore reduce the loss of cryogen. However, further improvement is desired.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide a simple and reliable technique to reduce heat input into a cryostat during transportation.
[0014] This object is achieved according to the invention by a cryostat that has an opening, in particular in the form of an access neck, a refrigerator interface, or the like, and that further has an insert removably positioned in the opening, wherein the insert is adapted to provide one or more passageways for a cryogen through the opening by defining at least one space between the outer surface of the insert and at least one part of the inner surface of the opening, this space allowing the cryogen to pass over the part of the inner surface of the opening.
[0015] The object of the present invention is also achieved by a method for reducing heat input into a cryostat, in particular during transportation of the cryostat, that includes the step of inserting an insert in an opening of the cryostat, which insert provides, once positioned into the opening, one or more passageways for a cryogen through the opening by defining at least one space between the outer surface of the insert and at least one part of the inner surface of the opening, this space allowing the cryogen to pass over the part of the inner surface of the opening.
[0016] The present invention is based upon the insight that not only does the refrigerator provide a low thermal resistance path for heat input into a cryostat during cold shipment, but also that the opening itself provides such a path for heat input into the cryostat. In particular the walls of the access neck or of other openings, which extend from the outside of the cryostat into the cryogenic vessel, create such heat paths.
[0017] This is true not only for the one opening of the cryostat which receives the refrigerator, but also for all other openings of the cryostat, which provide passages into the cryogenic vessel of the cryostat.
[0018] Therefore, a basis of the invention is to specifically target the warm inner surfaces of such openings in order to cool these inner surfaces by deliberately causing the cold cryogen gas to pass over these surfaces, reducing the parasitic heat load in a simple, reliable and very effective way.
[0019] Preferably, the insert is adapted such that the only way for the cryogen to pass through the opening is through the one or more passageways provided between the insert and the opening. In other words, the complete amount of cryogen gas to be exhausted is used in a particularly effective way for cooling purposes.
[0020] In order to provide a very effective way of cooling the inner surface of the opening, the insert is preferably adapted in a way that it fills out substantially the complete volume of the opening, once inserted into the opening. In other words, the insert is preferably formed in a way that there are no significant empty volumes within the opening, once the insert is inserted into the opening. Preferably, more or less the complete volume of the opening is filled with the insert, with the exception of the passageway(s) along the opening's inner surface.
[0021] According to a preferred embodiment of the invention the outer surface of the insert comprises structural elements, which are adapted to increase the length of the passageway through the opening. In other words, the structural elements are adapted to increase the period of time the cryogen passes over the inner surface of the opening. This even further improves the heat exchange and hence lowers the warm surface temperature.
[0022] According to a preferred embodiment of the invention the structural elements are spiral ridges, which are adapted to provide a spiraled passageway around the outer surface of the insert.
[0023] According to a preferred embodiment of the invention the outer surface of the insert is provided by walls made of low thermal conductivity material, said walls defining the hollow body of the insert. In this case, the insert is preferably being evacuated. According to an alternative embodiment of the invention the insert is a solid body made of low thermal conductivity foam. Both measures help to support the cooling effect of the passing cryogen fluid and to reduce the parasitic heat load.
[0024] In a preferred embodiment of the invention, such inserts are inserted into all suitable openings of the cryostat. In this case, the refrigerator and any other removable part are preferably removed from the said openings prior to inserting the inserts into it, in order to eliminate additional heat load caused by these removable parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic illustration of a cryostat.
[0026] FIG. 2 shows a refrigerator interface sock in a sectional view.
[0027] FIG. 3 shows an access neck in a sectional view.
[0028] FIG. 4 shows the access neck of FIG. 3 in a top-view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] A cross-section of a superconducting magnet system 1 for use in an MRI system is illustrated in FIG. 1 . A cryogenic refrigerator 2 is removably connected to the magnet system 1 by a refrigerator interface sock 4 (also known as an interface sleeve, or refrigerator interface) such that the refrigerator 2 is positioned in a receiving opening 5 of the interface sock 4 . Thereby, a first stage of the refrigerator cools a thermal shield 6 and a second stage cools the gas in the cryogen vessel 3 . A heat exchanger 8 , cooled by the second stage of the refrigerator 2 , is exposed to the interior of the cryogen vessel 3 , for example by a tube 9 .
[0030] Superconductive magnet coils (not shown) are provided in the cryogen vessel 3 . The coils are immersed in a liquid cryogen 7 , e.g. liquid helium. The thermal shield 6 completely surrounds the cryogen vessel 3 . A vacuum jacket 11 completely encloses the cryogen vessel 3 and the shield 6 in a vacuum. A central bore 12 is provided to accommodate a patient for examination. An access neck 13 is provided to allow access to the cryogen vessel 3 .
[0031] During transportation, when the refrigerator 2 is inoperative, boil-off of the cryogen 7 will occur. In a standard configuration, when the refrigerator 2 and heat exchanger 8 are not removed from the receiving opening 5 , boil-off gas generated in cryogen vessel 3 may leave the vessel either by the access neck 13 , or through the tube 9 , through the interface sock 4 past the refrigerator 2 .
[0032] Heat load on the cryogen vessel 3 during transportation comes from a number of sources, including the access neck 13 and the refrigerator interface sock 4 , and by radiation.
[0033] According to the present invention, for the purpose of transportation, the refrigerator 2 as well as any other removable device, e.g. the heat exchanger 8 , is removed from its position within the receiving opening 5 , in order to reduce heat load. For further reduction of heat load, an insert 14 is removably inserted into the interface sock 4 , as shown in more detail in FIG. 2 . After the transport of the superconducting magnet system 1 to the operational site has been completed, the insert 14 is removed and the refrigerator 2 as well as any other devices removed is fitted into the interface sock 4 again.
[0034] The insert 14 may be formed as hollow body defined by walls made of low thermal conductivity material, such as stainless steel or plastic. Preferably, the insert 14 is evacuated to minimize heat transfer. The top surface 15 of the insert 14 is covered in low emissivity material to reduce the incident radiation heat load from the top-plate 16 , which covers the receiving opening 5 .
[0035] The shape of the insert 14 corresponds to the inner contour of the receiving opening 5 of the interface sock 4 . In addition, the insert 14 extends preferably along the entire length 17 or essentially along the entire length 17 of the receiving opening 5 . The outer dimensions of the insert 14 are smaller than the inner dimensions of the receiving opening 5 such that, once inserted into the opening 5 , the insert 14 defines a space 18 between the outer surface 19 of the insert 14 and the inner surface 21 of the opening 5 . This space 18 provides a passageway for the boil-off cryogen 7 through the opening 5 , thereby passing over the warm surfaces 21 of the receiving opening 5 .
[0036] In order to force the cryogen 7 to pass over the inner surfaces 21 of the receiving opening 5 , the defined space 18 between the outer and inner surfaces 19 , 21 is preferably very small such that the cryogen 7 passes in close proximity over the inner surfaces 21 of the receiving opening 5 in order to provide good thermal contact to the inner surfaces 21 . Preferably, the average distance between the outer surface 19 of the insert 14 and the inner surface 21 of the receiving opening 5 is typically a few millimeters.
[0037] In order to ensure a defined position of the insert 14 within the receiving opening 5 , resulting in a defined space 18 between the inner and outer surfaces 19 , 21 , a support and/or hold structure is employed for holding the insert 14 in place. In the embodiment as illustrated in FIG. 2 , the support and/or hold structure is made of a spiral structure 22 , e.g. formed by machining or by attaching ridges on the outside surface 19 of the insert 14 . If the insert 14 is positioned within the receiving opening 5 , this spiral structure 22 contacts the inner surface 21 of the receiving opening 5 , defining a spiraled channel 23 from the bottom end 24 of the opening 5 towards the top end 25 of the opening 5 . In other words, a passageway is defined, wherein one part of said passageway is formed by the inner surface 21 of the receiving opening 5 . The channel 23 is considerably longer than the length 17 of the opening 5 , ensuring good heat exchange between the cryogen gas passing through the channel 23 and the warm inner surfaces 21 of the opening 5 . The channel 23 is at least two times as long as the length 17 of the opening 5 or at least two times as long as the length of the insert 14 , more preferably at least three times as long as the length 17 of the opening 5 or at least three times as long as the length of the insert 14 , and more preferably still, at least five times as long as the length 17 of the opening 5 or at least five times as long as the length of the insert 14 . The specific design of the passageway is used to direct the gas flow towards the inner surface 21 of the receiving opening 5 in order to ensure an intimate thermal contact.
[0038] During transportation, boil-off gas passes from the cryogen vessel 3 to be exhausted to the atmosphere along the passageway provided by the insert 14 . This cools the walls of the receiving opening 5 and reduces the ambient heat being conducted into the cryogen vessel 3 by the said walls. In particular, a gas flow pathway is formed from the cryogen vessel 3 to the top end 25 of the receiving opening 5 . Boil-off gas flows through the tube 9 , enters the receiving opening 5 of the interface sock 4 at its bottom end 24 , and runs through the spiraled channel 23 , thereby passing over the inner surface 21 of the opening 5 . The inner surfaces 21 of the opening 5 are cooled by the boil-off gas passing over it by virtue of the intimate thermal contact between the gas and surface 21 . In FIG. 2 the flow of the boil-off gas is indicated by arrows.
[0039] The opening 5 is sealed by the top plate 16 having a vent valve 26 , through which the cryogen gas exits the opening 5 . At the same time, there is no other way for the gas to exit this opening 5 , therefore, all the gas is used for cooling purposes. The optimal amounts of boil-off gas flow through the interface sock 4 are most readily determined by experiment to obtain the lowest heat load on the cryogen vessel 3 .
[0040] According to an embodiment of the present invention, an insert 28 is also inserted into the access neck 13 , as shown in more detail in FIG. 3 .
[0041] The access neck 13 provides e.g. for escape of cryogen gas in the event of a quench, during operation of the system, and for filling the cryogen 7 into the vessel 3 . The receiving opening 27 of the access neck 13 is closed by a turret 28 a, having again a sealing top plate 16 and a vent valve 26 for gas exit.
[0042] According to the present invention, for the purpose of transportation any removable device is removed from the receiving opening 27 , and an insert 28 is removably inserted into the access neck 13 , as shown in more detail in FIGS. 3 and 4 . Once the superconducting magnet system 1 is transported to the operational site, the insert 28 is removed and the removed devices are fitted into the access neck 13 again.
[0043] The insert 28 is generally similar to the insert 14 as described in connection with FIG. 2 . Again, the outer shape of the insert 28 corresponds to the inner contour of the receiving opening 27 of the access neck 13 . In this particular case, the receiving opening 27 contains an auxiliary vent tube 29 , which is held in position by flange piece 31 . This vent tube 29 cannot be removed prior to inserting the insert 28 into the opening 27 . Accordingly, the insert 28 is made of a cylindrical main element 32 and an extension piece 32 a which protrudes into the opening 27 beyond the flange piece 31 . Main element 32 has an eccentric cylindrical passage 33 for receiving the vent tube 29 when being inserted into the receiving opening 27 , see FIG. 3 .
[0044] By this means, the insert 28 is adapted to be positioned adjacent not only to the inner surfaces 21 of the receiving opening 27 but also to the outer surfaces 34 of the vent tube 29 , in both cases defining a space 18 to be used as passageway for boil-off gas to pass over said surfaces 21 , 34 . In other words, the insert 28 provides not only one but two passageways 18 , the first passageway being defined between the outer surface 19 of the insert 28 and the inner surface 21 of the receiving opening 27 , and the second passageway being defined between the inner surface 35 of the insert's passage 33 and the outer surface 34 of the vent tube 29 located within the receiving opening 27 .
[0045] In this particular embodiment, the insert 28 positioned in the access neck 13 is a solid body made of low thermal conductivity foam, and no ridges or the like are provided in order to form a spiraled passageway. Instead, the insert 28 is held in position within the receiving opening 27 by means of a support and/or hold structures in form of a number of spacers 36 .
[0046] However, alternative embodiments may provide insert 28 as a hollow thin-walled vessel of a material of low thermal conductivity, such as stainless steel or a composite material. Alternatively, the insert 28 may be formed of a solid piece of low thermal-conductivity material such as a polymer foam material. Ridges may be provided to define a spiraled pathway, similarly to the embodiment of FIG. 2 , in which case the spiraled channel is at least two times as long as the length of the opening 27 , more preferably at least three times as long as the length of the opening 27 , and more preferably still, at least five times as long as the length of the opening 27 .
[0047] During transportation, boil-off gas flows along the two passageways 18 provided by the insert 28 , thereby cooling the walls of the receiving opening 27 as well as the walls of the vent tube 29 .
[0048] Although modifications and changes 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.
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In a cryostat, in particular for use in a magnetic resonance imaging (MRI) system, and a method for reducing heat input into such a cryostat, an insert is provided that is adapted to be inserted into an opening of the cryostat. The insert is adapted to provide one or more passageways for a cryogen through the opening by defining at least one space between the outer surface of the insert and at least one part of the inner surface of the opening. This space allows the cryogen to pass over the part of the inner surface of the opening.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Korean Patent Application No. 10-2015-0125747, filed on Sep. 4, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a laundry treating apparatus, and more particularly to a laundry treating apparatus which performs washing by tumbling laundry.
[0004] 2. Description of the Related Art
[0005] In general, washing machines are classified into a top-loading washing machine, which performs washing using the rotational stream of wash water, and a drum washing machine which performs washing by tumbling laundry.
[0006] That is, the top-loading washing machine has a structure in which an inner vessel, serving as a washing vessel, is disposed so as to rotate about a direction perpendicular to the ground, and a pulsator provided on the bottom of the inner vessel rotates to generate a water stream, so as to perform washing through the friction between laundry and the water stream and by applying impacts to laundry by the pulsator. On the other hand, the drum washing machine has a structure in which an inner vessel, serving as a washing vessel, is disposed so as to rotate about a direction parallel to the ground, so as to perform washing through the friction between laundry and the inner wall surface of the inner vessel and by dropping laundry while the inner vessel rotates.
[0007] The drum washing machine is equipped with a lifter for tumbling (lifting and dropping) laundry when the inner vessel, which is a drum, rotates. The lifter consists of a plurality of lifters installed inside the drum so as to be spaced apart from each other in a circumferential direction which is the direction of rotation of the drum, and the lifters rotate along with the drum.
[0008] Each of the lifters protrudes inward from the drum to a predetermined height, at which the lifter does not lift laundry when the drum rotates at a low speed but lifts laundry when the drum rotates at a high speed. That is, the lifter tumbles the laundry accommodated in the drum using the rotary power of the drum only when the drum rotates at a predetermined speed.
[0009] Meanwhile, the drum is rotatably disposed in a tub, serving as a reservoir. Wash water collects in the bottom of the tub up to the level at which the water may flow into the bottom of the drum, in order to wet the laundry accommodated in the drum.
[0010] However, when a large amount of laundry is in the drum, only a portion of the laundry, namely that portion which is near the bottom of the drum, is wet. Accordingly, in order to sufficiently wet all of the laundry accommodated in the drum, the drum washing machine must be equipped with a motor for lifting the wash water, which collects in the tub, in the upward direction of the drum to spray the water on laundry.
SUMMARY OF THE INVENTION
[0011] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a laundry treating apparatus capable of sufficiently wetting laundry in a drum by spraying wash water in a tub on the laundry.
[0012] Additional advantages, objects, and features 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 the invention.
[0013] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a laundry treating apparatus including a tub configured to accommodate wash water, a drum rotatably disposed in the tub, and configured to accommodate laundry, and a lifter disposed in the drum, to tumble the laundry using rotary power of the drum, wherein the drum has a drum hole communicating with an inner space of the lifter, and the lifter has a lifter hole through which the wash water, introduced into the inner space from the tub through the drum hole, is sprayed on the laundry at a predetermined position to which the drum rotates.
[0014] The objectives and other advantages 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0016] FIG. 1 is a perspective view illustrating a laundry treating apparatus according to a first embodiment of the present invention;
[0017] FIG. 2 is a cross-sectional view of a drum, lifters, and a tub illustrated in FIG. 1 ;
[0018] FIG. 3 is a view of the outside of the drum and the lifters illustrated in FIG. 1 ;
[0019] FIG. 4 is a front perspective view of one of the lifters illustrated in FIG. 1 ;
[0020] FIG. 5 is a cross-sectional view of the lifter illustrated in FIG. 4 ;
[0021] FIG. 6 is a back perspective view of one of the lifters illustrated in FIG. 1 ;
[0022] FIG. 7 is a view illustrating a lifter of a laundry treating apparatus according to a second embodiment of the present invention;
[0023] FIG. 8 is a view illustrating a lifter of a laundry treating apparatus according to a third embodiment of the present invention;
[0024] FIG. 9 is a front perspective view illustrating a lifter of a laundry treating apparatus according to a fourth embodiment of the present invention;
[0025] FIG. 10 is a back perspective view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention; and
[0026] FIG. 11 is a back view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Reference will now be made in detail to embodiments, examples of which are illustrated in 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. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention.
[0028] Hereinafter, a laundry treating apparatus according to exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.
[0029] The laundry treating apparatus according to exemplary embodiments of the present invention includes all apparatuses for treating laundry. Specifically, the laundry treating apparatus includes washing machines that remove contaminants from laundry using wash water, and washing machines that perform both washing and drying.
[0030] FIG. 1 is a perspective view illustrating a laundry treating apparatus according to a first embodiment of the present invention.
[0031] Referring to FIG. 1 , the laundry treating apparatus according to the first embodiment of the present invention may include a cabinet 2 and a control panel 4 installed on the cabinet 2 .
[0032] The cabinet 2 may be a case that defines the external appearance of the laundry treating apparatus. The cabinet 2 may have a laundry entry port 3 for the insertion and removal of laundry into and from the cabinet 2 . A tub 30 (see FIG. 2 ) for accommodating wash water may be installed in the cabinet 2 .
[0033] A drum 40 for accommodating laundry may be rotatably installed in the tub. A motor (not shown) for rotating the drum 40 may be installed in the cabinet 2 .
[0034] The cabinet 2 may be configured by bending a single member many times, or may be configured by coupling a large number of members to each other. The cabinet 2 may include a base fan (not shown), a cabinet body 8 , which is installed at the base fan and has a space for accommodating the tub, a cabinet cover 10 , which is disposed in front of the cabinet body 8 and has the laundry entry port 3 formed thereon, and a top cover 12 disposed at the upper portion of the cabinet body 8 .
[0035] The cabinet body 8 may be configured of a single member or a plurality of members. The cabinet body 8 may include a left cover disposed at the left upper portion of the base fan, a right cover disposed at the right upper portion of the base fan, and a rear cover disposed at the rear upper portion of the base fan. Of course, the cabinet 2 may be configured as a combination of a plurality of members, and may be changed in various forms.
[0036] The cabinet 2 may be equipped with a door 14 for opening and closing the laundry entry port 3 . The door 14 may be rotatably or slidably connected to the cabinet 2 so as to open and close the laundry entry port 3 . The door 14 may be connected to the cabinet 2 by a hinge mechanism in order to open and close the laundry entry port 3 while rotating about the hinge mechanism.
[0037] The control panel 4 may include an operation unit for operating the laundry treating apparatus. The control panel 4 may include a display unit for displaying information about the laundry treating apparatus. The control panel 4 may include the operation unit and the display unit together. The control panel 4 may be installed on the cabinet 2 . The control panel 4 may be disposed on the upper portion of the cabinet cover 10 . The control panel 4 may be located on the front upper portion of the cabinet 2 , and may define a portion of the external appearance of the laundry treating apparatus.
[0038] The control panel 4 may include a control panel body 20 . The control panel body 20 may define the external appearance of the control panel 4 . The control panel body 20 may be located above the cabinet cover 10 , and may be provided with the operation unit which is operated by a user, and the display unit which displays various types of information about the laundry treating apparatus to the outside.
[0039] The control panel 4 may include a rotary knob 50 which is gripped and operated by the user's hand. The rotary knob 50 may be installed to select various courses of the laundry treating apparatus, and the user may grip and turn the rotary knob 50 in order to select various courses of the laundry treating apparatus. The control panel body 20 may have an opening 22 which is larger than the rotary knob 50 . The rotary knob 50 may be disposed such that the front portion thereof is located in front of the opening 22 .
[0040] The control panel 4 may include a knob decoration 56 located around the rotary knob 50 . The knob decoration 56 may be located between the outer circumference of the rotary knob 50 and the opening 22 . The knob decoration 56 may realize a high-quality external appearance around the rotary knob 50 , and may have the same color as the outer surface of the control panel body 20 .
[0041] The control panel 4 may further include a window 82 which is disposed to surround the outer circumference of the rotary knob 50 . The laundry treating apparatus may further include a light source which irradiates the window with light. Light incident on the window 82 may penetrate the window 82 , and the user may recognize various types of information about the laundry treating apparatus by checking the shape or location of light radiated to the window 82 . A portion of the window 82 may be exposed outward between the knob decoration 56 and the opening 22 , and light may be radiated through the exposed portion of the window 82 .
[0042] A lifter 45 may be installed in the drum 40 . The lifter 45 may consist of a plurality of lifters which are installed so as to be spaced apart from each other at regular intervals along the inner peripheral surface of the drum 40 . The lifters 45 may rotate along with the drum 40 when the drum 40 rotates. The lifters 45 may tumble the laundry accommodated in the drum 40 using the rotary power of the drum 40 , thereby enabling the laundry to be washed. The lifters 45 may not lift the laundry accommodated in the drum 40 when the drum 40 rotates at a low speed, but may lift and drop the laundry accommodated in the drum 40 when the drum 40 rotates at a high speed.
[0043] FIG. 2 is a cross-sectional view of the drum, the lifters, and the tub illustrated in FIG. 1 . FIG. 3 is a view of the outside of the drum and the lifters illustrated in FIG. 1 .
[0044] Referring to FIGS. 2 and 3 , the drum 40 may have a drum hole 41 , through which the wash water accommodated in the tub 30 is guided to the inner space in each of the lifters 45 . The drum hole 41 may consist of three drum holes which are spaced apart from each other at regular intervals in the direction of axial rotation of the drum 40 (hereinafter, referred to as an “axial direction”). The drum holes 41 preferably communicate with the inner spaces of the lifters 45 such that the wash water accommodated in the tub 30 may flow into the inner spaces of the lifters 45 through the drum holes 41 . The number of drum holes 41 is not limited to three, but one or more drum holes may be formed at positions corresponding to the inner spaces of the lifters 45 .
[0045] The drum 40 may further have a scoop 42 which is formed at one side of each of the drum holes 41 . The scoop 42 may have a shape that is concave at the outside of the drum 40 and is convex at the inside thereof. The scoop 42 is preferably formed at one side of the drum hole 41 such that the wash water in the tub 30 may be guided to the drum hole 41 only when the drum 40 rotates in one direction. Here, the one direction in which the drum 40 rotates is a clockwise direction. When the drum 40 rotates clockwise, the scoop 42 is preferably disposed in front of the drum hole 41 in the clockwise direction. That is, only when the drum 40 rotates clockwise, the scoop 42 guides the wash water in the tub 30 to the drum hole 41 so that the wash water may flow into the inner space in each of the lifters 45 through the associated drum hole 41 .
[0046] The lifter 45 has a lifter hole 45 a through which the wash water introduced into the inner space from the tub 30 through the drum hole 41 is sprayed on laundry at a predetermined position to which the drum 40 rotates. That is, the wash water, which is introduced into the inner space of the lifter 45 through the drum hole 41 at position A, illustrated in FIG. 2 , is sprayed on laundry through the lifter hole 45 a at position B, illustrated in FIG. 2 . In order to spray the wash water, which is introduced into the inner space of the lifter 45 , on laundry, the lifter hole 45 a is formed in a direction perpendicular to the tangent line of the drum 40 . Position A, illustrated in FIG. 2 , is the position at which the lifter 45 passes the bottom of the tub 30 and at which wash water collects in the tub 30 .
[0047] The lifter 45 may consist of three lifters which are circumferentially arranged at a distance of 120° on the inner peripheral surface of the drum 40 . That is, the distance between position A and position B, illustrated in FIG. 2 , is a distance of 120°. In the embodiment, the wash water introduced into the inner space of the lifter 45 through the drum hole 41 at position A may be sprayed on laundry through the lifter hole 45 a at position B to which the drum 40 rotates at an angle of 120°. Of course, the number of lifters 45 is not limited to three.
[0048] FIG. 4 is a front perspective view of one of the lifters illustrated in FIG. 1 . FIG. 5 is a cross-sectional view of the lifter illustrated in FIG. 4 .
[0049] Referring to FIGS. 4 and 5 , the lifter 45 is axially elongated. The lifter 45 includes a round surface 46 which protrudes maximally inward from the drum 40 , a first inclined surface 47 which is disposed at one side of the round surface 46 in one direction of rotation (in the clockwise direction) of the drum 40 , a second inclined surface 48 which is disposed at the other side of the round surface 46 in the other direction of rotation of the drum 40 , a front surface 49 which extends from the front ends of the round surface 46 , the first inclined surface 47 , and the second inclined surface 48 , and a rear surface (not shown) which extends from the rear ends of the round surface 46 , the first inclined surface 47 , and the second inclined surface 48 .
[0050] The round surface 46 is a curved surface that is convex toward the center of the drum 40 . Each of the first and second inclined surfaces 47 and 48 is inclined at a predetermined angle relative to the inner surface of the drum 40 , and generally has a flat shape. The inner angle (a) between the first inclined surface 47 and the inner surface of the drum 40 is defined as a first angle, and the inner angle (b) between the second inclined surface 48 and the inner surface of the drum 40 is defined as a second angle. In the embodiment, the first angle is an angle of 48°.
[0051] One end of each of the first and second inclined surfaces 47 and 48 extends from the round surface 46 , and the other end thereof may be coupled to the drum 40 .
[0052] The lifter hole 45 a is formed in the round surface 46 and the first inclined surface 47 , but is not formed in the second inclined surface 48 . The lifter hole 45 a may consist of a plurality of lifter holes which are spaced apart from each other at regular intervals throughout the first inclined surface 47 , and may consist of a plurality of lifter holes which are formed in a portion of the round surface 46 so as to corresponding to the lifter holes 45 a formed in the first inclined surface 47 . The lifter holes 45 a formed in the round surface 46 are arranged in one row, and the lifter holes 45 a formed in the first inclined surface 47 are arranged in a plurality of rows.
[0053] In the embodiment, the lifter has a hole ratio of 0.8. The hole ratio is a value obtained by dividing a sum of lengths occupied by lifter holes 45 a by a remaining length, in a rectilinear length (L) to the tip end of the first inclined surface 47 from the center of a lifter hole 45 a closest to the center of the drum 40 .
[0054] FIG. 6 is a back perspective view of one of the lifters illustrated in FIG. 1 .
[0055] Referring to FIGS. 2 and 6 , fastening structures for mounting the lifter 45 to the drum 40 are formed on the back surface of the lifter 45 and the drum 40 . The fastening structures includes first and second sliding holes 43 a and 43 b and a fastening hole 44 which are formed in the drum 40 , and a sliding protrusion 45 b and a fastening portion 45 c which are formed on each lifter 45 .
[0056] The first and second sliding holes 43 a and 43 b are formed so as to be spaced apart from each of the drum holes 41 in one direction, and the fastening hole 44 is formed so as to be spaced apart from the drum hole 41 in a direction opposite to the direction.
[0057] The first sliding hole 43 a is axially elongated, and has a width perpendicular to the axial direction thereof, the width being greater than that of the second sliding hole 43 b . The second sliding hole 43 b extends from the first sliding hole 43 a so as to be axially elongated, and has a width perpendicular to the axial direction thereof, the width being smaller than that of the first sliding hole 43 a.
[0058] The sliding protrusion 45 b is axially elongated. The sliding protrusion 45 b is formed on one side in the lifter 45 , and in more detail, is formed on the first inclined surface 47 . The fastening portion 45 c is formed on the other side in the lifter 45 , and in more detail, is formed on the second inclined surface 48 .
[0059] After the sliding protrusion 45 b is inserted into the first sliding hole 43 a formed in the drum 40 , the lifter 45 is coupled to the drum 40 by the sliding of the sliding protrusion 45 b from the first sliding hole 43 a to the second sliding hole 43 b . When the sliding protrusion 45 b is located in the second sliding hole 43 b and the lifter 45 is coupled to the drum 40 , the first sliding hole 43 a communicates with the inner space of the lifter 45 . Accordingly, when the drum 40 rotates in one direction, the wash water in the tub 30 may flow into the inner space of the lifter 45 through the drum hole 41 , and may also flow into the inner space of the lifter 45 through the first sliding hole 43 a.
[0060] The sliding protrusion 45 b preferably has a length and a width corresponding to those of the second sliding hole 43 b such that it may be pressed against the second sliding hole 43 b and the lifter 45 may be coupled to the drum 40 .
[0061] The lifter 45 is coupled to the drum 40 by inserting a screw, serving as a fastening member, into the fastening portion 45 c . That is, the screw is inserted and coupled into the fastening portion 45 c through the fastening hole in the outside of the drum 40 , thereby allowing the other side of the lifter 45 to be coupled to the drum 40 .
[0062] As described above, only one side of the lifter 45 , which is in one direction of rotation of the drum 40 , slides and is coupled to the drum 40 through the sliding protrusion 45 b , and the other side thereof is coupled to the drum 40 through the fastening portion 45 c . Thus, when the drum 40 rotates in one direction, the wash water in the tub 30 flows into the inner space of the lifter 45 through the drum hole 41 and the first sliding hole 43 a , and the wash water introduced into the inner space is not discharged through the other side of the lifter 45 . Therefore, the wash water introduced into the lifter 45 may be sprayed on laundry through the lifter hole 45 a at a predetermined position to which the drum 40 rotates.
[0063] After one side of the lifter 45 is first coupled to the drum 40 by coupling the sliding protrusion 45 b to the second sliding hole 43 b , the other side of the lifter 45 is coupled to the drum 40 by inserting the screw into the fastening hole 44 and the fastening portion 45 c . Consequently, the process in which the lifter 45 is mounted to the drum 40 may be completed.
[0064] The lifter 45 has an open surface which comes into contact with the inner surface of the drum 40 . The lifter 45 has a plurality of partition walls 45 d for partitioning the inner space into a plurality of regions. Each of the partition walls 45 d may be formed so as to extend from the round surface 46 and the first and second inclined surfaces 47 and 48 . The partition wall 45 d has a recessed portion 45 e formed by depressing a portion of the partition wall 45 d toward the inner surface of the drum 40 . The recessed portion 45 e is disposed at a position corresponding to the drum hole 41 and the scoop 42 formed in the drum 40 . The wash water introduced into the inner space of the lifter 45 through the drum hole 41 may axially flow through the recessed portion 45 e in the lifter 45 . A portion of the partition wall 45 d , which extends from the second inclined surface 48 , may extend from the fastening portion 45 c.
[0065] FIG. 7 is a view illustrating a lifter of a laundry treating apparatus according to a second embodiment of the present invention. In the second embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described.
[0066] Referring to FIG. 7 , it can be seen that the lifter, which is designated by reference numeral 145 , of the laundry treating apparatus according to the second embodiment of the present invention differs from the lifter 45 of the first embodiment. That is, in the first embodiment, the lifter holes 45 a are formed so as to be spaced apart from each other at regular intervals throughout the first inclined surface 47 , and the lifter holes 45 a are formed in a portion of the round surface 46 so as to correspond to the lifter holes 45 a formed in the first inclined surface 47 . However, the second embodiment is identical to the first embodiment in that a plurality of lifter holes 45 a is formed so as to be spaced apart from each other at regular intervals throughout a first inclined surface 47 , but the second embodiment differs from the first embodiment in that a plurality of lifter holes 45 a is formed so as to be spaced apart from each other at regular intervals throughout a round surface 46 . In the second embodiment, the lifter holes 45 a formed in the round surface 46 are arranged in three rows.
[0067] FIG. 8 is a view illustrating a lifter of a laundry treating apparatus according to a third embodiment of the present invention. In the third embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described.
[0068] Referring to FIG. 8 , it can be seen that the lifter, which is designated by reference numeral 245 , of the laundry treating apparatus according to the third embodiment of the present invention differs from the lifter 45 of the first embodiment. That is, in the first embodiment, the lifter holes 45 a are formed so as to be spaced apart from each other at regular intervals throughout the first inclined surface 47 , and the lifter holes 45 a are formed in a portion of the round surface 46 so as to correspond to the lifter holes 45 a formed in the first inclined surface 47 . However, the third embodiment is identical to the first embodiment in that a plurality of lifter holes 45 a is formed so as to be spaced apart from each other at regular intervals throughout a first inclined surface 47 , but the third embodiment differs from the first embodiment in that no lifter holes are formed in a round surface 46 .
[0069] In addition, in the lifter 245 of the third embodiment, the first inclined surface 47 formed with the lifter holes 45 a has an axially asymmetrical shape. Accordingly, when the drum 40 rotates in one direction, the lifter 245 may move to a predetermined position in the state in which wash water collects in the inner space of the lifter 245 .
[0070] FIG. 9 is a front perspective view illustrating a lifter of a laundry treating apparatus according to a fourth embodiment of the present invention. FIG. 10 is a back perspective view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention. FIG. 11 is a back view illustrating the lifter of the laundry treating apparatus according to the fourth embodiment of the present invention. In the fourth embodiment, like reference numerals refer to the same components as those of the first embodiment, and a detailed description thereof will be omitted. Moreover, only differences from the first embodiment will be described.
[0071] Referring to FIGS. 9 to 11 , it can be seen that the lifter, which is designated by reference numeral 345 , of the laundry treating apparatus according to the fourth embodiment of the present invention differs from the lifter 45 of the first embodiment. That is, in the lifter of the first embodiment, the lifter holes 45 a are formed in the round surface 46 and the first inclined surface 47 . However, in the lifter 345 of the fourth embodiment, a plurality of lifter holes 45 a is formed only in a round surface 46 . The lifter holes 45 a formed in the lifter 345 of the fourth embodiment are arranged in one row in the round surface 46 .
[0072] In addition, in the drum 40 of the first embodiment, the first and second sliding holes 43 a and 43 b are formed so as to be spaced apart from the drum hole 41 in one direction, and the fastening hole 44 is formed so as to be spaced apart from the drum hole 41 in a direction opposite to the direction. However, the fourth embodiment is identical to the first embodiment in that first and second sliding holes 43 a and 43 b are formed so as to be spaced apart from the drum hole 41 in one direction in the drum 40 , but the fourth embodiment differs from the first embodiment in that third and fourth sliding holes 44 a and 44 b are formed so as to be spaced apart from the drum hole in a direction opposite to the direction. Here, the third sliding hole 44 a has the same structure and function as the first sliding hole 43 a , and the fourth sliding hole 44 b has the same structure and function as the second sliding hole 43 b.
[0073] In the lifter 45 of the first embodiment, the sliding protrusion 45 b is formed only on the first inclined surface 47 , and the fastening portion 45 c is formed on the second inclined surface 48 . However, in the fourth embodiment, sliding protrusions 45 b and 45 f are formed on both first and second inclined surfaces 47 and 48 . That is, the sliding protrusions 45 b and 45 f include a first sliding protrusion 45 b which is coupled by sliding to the second sliding hole 43 b from the first sliding hole 43 a , and a second sliding protrusion 45 f which is coupled by sliding to the fourth sliding hole 44 b from the third sliding hole 44 a.
[0074] When the first sliding protrusion 45 b is located in the second sliding hole 43 b , the first sliding hole 43 a is opened. Thus, when the drum 40 rotates in one direction, the wash water in the tub 30 may be introduced into the inner space of the lifter 345 through the drum hole 41 and the first sliding hole 43 a.
[0075] Meanwhile, the second sliding protrusion 45 f further has a shield wall 45 g formed at one side thereof. The shield wall 45 g shields the third sliding hole 44 a when the second sliding protrusion 45 f is located in the fourth sliding hole 44 b . Therefore, when the drum 40 rotates in one direction, it is possible to prevent the wash water accommodated in the inner space of the lifter 345 from flowing out through the third sliding hole 44 a.
[0076] In addition, the drum 40 of the fourth embodiment may further have fastening holes 44 which are formed as components corresponding to the fastening hole 44 of the first embodiment. One of the fastening holes 44 may be formed in a portion corresponding to the front portion of the lifter 345 , and the remaining one may be formed in a portion corresponding to the rear portion of the lifter 345 .
[0077] The lifter 345 may have a fastening portion 45 c which is formed as a component corresponding to the fastening portion 45 c of the first embodiment. Similar to the first embodiment, the lifter 345 may be coupled to the drum 40 by inserting a screw, serving as a fastening member, into the fastening portion 45 c . That is, the screw is inserted and coupled into the fastening portion 45 c through the fastening hole 44 in the outside of the drum 40 , thereby allowing the lifter 345 to be securely coupled to the drum 40 .
[0078] As described above, in the laundry treating apparatus according to the embodiments of the present invention, the wash water in the tub 30 is introduced into the inner space of the lifter 45 , 145 , 245 , or 345 through the drum hole 41 , and is then sprayed on laundry through the lifter holes 45 a at a predetermined position to which the drum 40 rotates. Therefore, the laundry treating apparatus can eliminate a motor for lifting the wash water in the tub 30 in the upward direction of the drum 40 , whereby it can reduce costs, weight, and noise and save electricity.
[0079] As is apparent from the above description, a laundry treating apparatus according to exemplary embodiments of the present invention has effects of reducing costs, weight, and noise and saving electricity since it can eliminate a motor for lifting the wash water in a tub in the upward direction of a drum.
[0080] The present invention is not limited to the foregoing effects, and other effects thereof will be clearly understood by those skilled in the art from the above description and the following claims.
[0081] Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and applications may be devised by those skilled in the art that will fall within the intrinsic aspects of the embodiments. More particularly, various variations and modifications are possible in concrete constituent elements of the embodiments. In addition, it is to be understood that differences relevant to the variations and modifications fall within the spirit and scope of the present disclosure defined in the appended claims.
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Disclosed herein is a laundry treating apparatus capable of sufficiently wetting laundry in a drum by spraying wash water in a tub on the laundry, without a motor. The laundry treating apparatus includes a tub configured to accommodate wash water, a drum rotatably disposed in the tub, and configured to accommodate laundry, and a lifter disposed in the drum, to tumble the laundry using rotary power of the drum, wherein the drum has a drum hole communicating with an inner space of the lifter, and the lifter has a lifter hole through which the wash water, introduced into the inner space from the tub through the drum hole, is sprayed on the laundry at a predetermined position to which the drum rotates.
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This application claims the benefit of U.S. Provisional Application Ser. No. 60/403,438, filed Aug. 15, 2002, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the field of surgery reconstruction and, in particular, to a meniscal allograft technique and system using a meniscal allograft having a dovetail notch.
BACKGROUND OF THE INVENTION
A known method of performing an anatomical reconstruction of the meniscus is the so-called meniscal allograft “keyhole” technique using instrumentation sold by Arthrex, Inc. of Naples, Fla. In this technique, the bone block of a meniscal allograft is formed in the shape of a keyhole plug, to match a corresponding keyhole groove prepared through the cortical and cartilagenous surface of the tibial plateau. The bone plug for the meniscal allograft is then fed into the keyhole groove, such that the meniscal allograft is mounted on the tibial plateau and secured without transosseous sutures.
Although the above-described technique is a vast improvement over prior meniscal allograft technique, the “keyhole” shape of the allograft implant is difficult to reproduce and necessitates a long preparation time, typically about 45 minutes. Thus, although the “keyhole” technique described above is a vast improvement over prior meniscal allograft techniques, it would be desirable to provide a meniscal transplant system and technique that is quicker, easier and more reproducible.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the “keyhole” technique by providing a meniscal allograft technique using a meniscus allograft having a trapezoidal shape in cross-section, as opposed to a “keyhole” shape. The trapezoidal shape is more easily reproducible than a “keyhole” shape. Preferably, the dovetail meniscus allograft has a trapezoidal shape with a 90 degree angle and is formed as a pre-cut meniscal allograft.
The dovetail meniscus allograft of the present invention is advanced into a same-size dovetail groove of a bone by impaction. The dovetail groove is formed initially using drill bits. Dilators are used to increase the size of the drilled openings. The orthogonal corner at the bottom of the groove is shaped using a rasp. A smooth dilator compacts the bone in the acute angle at the bottom of the groove opposite the orthogonal corner to create the final dovetail shape.
These and other features and advantages of the invention will be more apparent from the following detailed description that is provided in connection with the accompanying drawings and illustrated exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary dovetail allograft implant according to the present invention at an initial stage of fabrication.
FIG. 2 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 1 .
FIG. 3 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 2 .
FIG. 4 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 3 .
FIG. 5 illustrates another view of the dovetail allograft implant of FIG. 5 .
FIG. 6 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 4 .
FIG. 7 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 6 .
FIG. 8 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 7 .
FIG. 9 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 8 .
FIG. 10 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 9 .
FIG. 11 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 10 .
FIG. 12 illustrates another view of the dovetail allograft implant of FIG. 11 .
FIG. 13 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 11 .
FIG. 14 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 13 .
FIG. 15 illustrates the dovetail allograft implant of FIG. 1 at a stage of fabrication subsequent to that shown in FIG. 14 .
FIG. 16 illustrates another view of the dovetail allograft implant of FIG. 15 .
FIG. 17 illustrates yet another view of the dovetail allograft implant of FIG. 15 .
FIG. 18 illustrates a tibia for forming a dovetail tibial groove that accommodates the dovetail allograft implant of FIGS. 15–17 .
FIG. 19 illustrates a method of forming a dovetail tibial groove that accommodates the dovetail allograft implant of FIGS. 15–17 according to the present invention and at an initial stage of formation.
FIG. 20 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 19 .
FIG. 21 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 20 .
FIG. 22 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 21 .
FIG. 23 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 22 .
FIG. 24 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 23 .
FIG. 25 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 24 .
FIG. 26 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 25 .
FIG. 27 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 26 .
FIG. 28 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 27 .
FIG. 29 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 28 .
FIG. 30 illustrates the dovetail tibial groove of the present invention at a stage of formation subsequent to that shown in FIG. 29 .
FIG. 31 illustrates another view of the dovetail tibial groove of FIG. 30 .
FIG. 32 illustrates the dovetail allograft implant of FIGS. 15–17 inserted into the dovetail tibial groove of FIG. 31 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a meniscal allograft technique for forming a longitudinal groove in a bone, the groove having a trapezoidal or dovetail cross-section, and providing a pre-cut meniscal allograft also having a trapezoidal or dovetail cross-section. The trapezoidal shape of the pre-cut meniscal allograft is more easily reproducible than a “keyhole” shape.
Referring now to the drawings, where like elements are designated by like reference numerals, FIGS. 1–17 illustrate an exemplary embodiment of a dovetail meniscal allograft implant 100 ( FIGS. 15–17 ) fabricated according to the present invention, while FIGS. 18–31 illustrate the formation of a longitudinal dovetail tibial groove 99 ( FIG. 31 ) that accommodates the dovetail meniscal allograft implant 100 . FIG. 32 illustrates the dovetail meniscal allograft implant 100 of FIGS. 15–17 inserted into the dovetail tibial groove 99 of FIG. 31 .
The dovetail meniscus implant 100 can be machined from allograft cortical bone using known techniques, and is preferably a single piece of harvested material with the meniscus on a bone block. Alternatively, the implant can be formed of a synthetic material, preferably a synthetic cortical bone material. A preferred synthetic bone material is tricalcium phosphate (TCP) and/or hydroxyapatite (HA), or a biodegradable polymer, preferably a polylactide, such as PLLA.
FIG. 1 illustrates a meniscus 10 formed of allograft cortical bone. As shown in FIG. 1 , meniscus 10 is first mounted on a graft workstation, where bone block 14 is marked and trimmed to a length “L” corresponding to the longitudinal length of dovetail tibial groove 99 (the formation of which will be described in more detail below with reference to FIGS. 17–30 ). Referring to FIG. 2 , any additional bone that is anterior or posterior to the sides of horns 12 of meniscus 10 is removed. FIG. 3 shows the marking of dovetail configuration A onto both the anterior and posterior facets of the bone block 14 , so that the horns 12 are centered on side A 4 of the trapezoid or dovetail configuration A. The dovetail configuration A is a cross-sectional trapezoidal shape with four edges A 1 (height), A 2 (base), A 3 and A 4 (small base), edges A 1 and A 2 forming a ninety degree angle and edges A 2 and A 3 forming an acute dovetail angle α, as shown in FIG. 3 . The acute dovetail angle α is about 25 degrees to about 75 degrees, more preferably about 45 degrees.
FIGS. 4 and 5 illustrate meniscus 10 secured between two grafting holding posts and positioned upside down. As shown in FIGS. 4 and 5 , meniscus 10 hangs freely and away from the bone block 14 , so that the edge A 1 of the dovetail configuration A is aligned with the holding posts. As also illustrated in FIG. 4 , base A 2 is aligned with the bottom of the holding posts.
Referring now to FIGS. 6–8 , a first cutting jig 21 is aligned ( FIGS. 6 , 7 ) to the edge A 1 of the of the meniscus 10 , so that bone from the bone block 14 is vertically cut ( FIG. 8 ) along the edge A 1 of the dovetail configuration A. A second cutting jig 22 ( FIG. 9 ) is then aligned with the flat base A 2 so that bone from the block 14 is horizontally cut along the base A 2 of the dovetail configuration A of the bone block 14 , as shown in FIG. 10 . The length of the edge A 1 of the dovetail configuration A is of about 8 mm to about 12 mm, more preferably of about 10 mm. The length of the base A 2 of the dovetail configuration A is of about 8 mm to about 12 mm, more preferably of about 10.5 mm.
FIGS. 11–14 illustrate cutting of bone from the bone block 14 along edge A 3 of the dovetail configuration A using a third cutting jig 23 , to define the length of the edge or small base A 4 and to complete the fabrication of body 15 of the dovetail meniscal allograft implant 100 . The length of the small base A 4 is of about 5 mm to about 10 mm, more preferably of about 7 mm. As illustrated in FIGS. 15 , 16 and 17 , which are more detailed illustrations of the dovetail meniscal allograft implant 100 fabricated as described above, body 15 is defined by the four edges (A 1 , A 2 , A 3 and A 4 ) of the dovetail or trapezoid configuration A, with the horns 12 of the meniscus 10 attached to the surface defined by the small base A 4 and the length L of the body 15 .
A method of forming longitudinal dovetail tibial groove 99 ( FIG. 30 ) is now described with reference to FIGS. 18–31 and by using known techniques of drilling through the tibia 50 , shown in FIG. 18 . The longitudinal tibial groove 99 of the present invention has a dovetail configuration and a size that accommodates the insertion of the dovetail meniscal allograft implant 100 fabricated as described above.
Osteotome 55 and alignment guide 53 are assembled, as shown in FIG. 18 , after debriding the remaining meniscus just to the periphery, leaving only a thin cartilaginous peripheral rim attached to the capsule. Using a high speed bur, the lateral tibial eminence is shaved down until there is a bleeding vascular bed. Removal of the tibial eminence enhances exposure and ensures proper placement of the drill guide, as described in more detail below. Alignment rod 54 ( FIG. 19 ) is then positioned in an anterior to posterior plane, entered through the anterior and posterior horns 57 and 58 , respectively, of the tibial meniscus. FIG. 20 illustrates osteotome 55 and alignment rod 54 positioned so that the osteotome 55 can advance into the proximal side of tibia 50 through the horns 57 , 58 so that the top of the osteotome 55 is flush with tibial plateau 51 and stops at the posterior horn 58 , as shown in FIG. 21 .
The handle of osteotome 55 is then removed, leaving its blade 55 a into position. A first Drill Guide 60 is subsequently positioned over the blade 55 a , flush to the anterior tibia, as shown in FIG. 22 . Using a 6 mm drill bit 61 ( FIG. 23 ), the tibial plateau 51 is cut through and drilled through the first Drill Guide 60 , from the anterior horn 57 to the posterior horn 58 for a distance “L” which illustrates the length of the dovetail meniscal implant 100 ( FIG. 17 ). FIG. 24 illustrates the 6 mm drill bit 61 cutting through the plateau channel and advancing through into the tibia under direct visualization until it contacts the posterior tibial cortex.
The first Drill Guide 60 that accommodates the 6 mm drill bit 61 is then removed from the osteotome 55 , so that a second Drill Guide 70 is attached to the osteotome 55 , as shown in FIG. 25 . The second Drill Guide 70 accommodates an 8 mm drill bit 71 ( FIG. 25 ) to drill through the tibial plateau 51 from the anterior horn 57 to the posterior horn 58 , in a way similar to that using the 6 mm drill bit 61 . A curette may be optionally used to further debride the groove subsequent to the drilling operation. FIG. 26 illustrates tibial groove 90 formed within tibia 50 at the end of the drilling operation with both the 6 mm drill bit 61 and 8 mm drill bit 71 .
A rasp 75 is subsequently used to create the orthogonal angle of the dovetail configuration A ( FIGS. 15 , 16 and 17 ) into the tibial groove 90 , as shown in FIG. 27 . The rasp 75 must remain flush to the articular surface of the tibia and may be slowly advanced with a combination of maletting and hand rasping until it reaches the posterior tibial cortex. A dilatator 80 ( FIGS. 28 , 29 ) may be also inserted in the tibial groove 90 to increase the size of the drilled channel and to form the dovetail acute angle α of the dovetail configuration A ( FIGS. 15 , 16 and 17 ), using gentle taps of a mallet if necessary, and to complete the formation of the longitudinal dovetail tibial groove 99 , as shown in FIGS. 30 and 31 .
The longitudinal dovetail tibial groove 99 has a size and a length “L” that accommodate the dovetail meniscal allograft implant 100 fabricated as described above. By placing a ruler inside the prepared tibial groove 99 , the length L is properly measured and then transferred onto the allograft bone block 14 of FIG. 1 , to prepare the formation of the dovetail meniscal allograft implant 100 , as described above with reference to FIGS. 15–17 .
Finally, the dovetail meniscal allograft implant 100 is passed into the recipient dovetail tibial groove 99 , as shown in FIG. 32 , and the dovetail groove is cleared of any remaining bone debris in the posterior portion of the tibia. As the dovetail meniscal allograft implant 100 is delivered to the tibial groove 99 , the graft passing suture attached to the meniscal allograft implant 100 is lead out the posterior lateral capsule via a standard inside out meniscal suturing technique. A meniscal allograft tamp may be employed to position the meniscal allograft implant 100 into the dovetail tibial groove 99 .
As described above, the invention provides an improvement over the “keyhole” technique in that the shapes of the dovetail meniscal allograft implant 100 and of the corresponding longitudinal dovetail tibial groove 99 are more easily reproducible compared to the “keyhole” structures. Further, the invention provides a method of fabricating a meniscal allograft implant, such as the dovetail meniscal allograft implant 100 , in about 5 to 8 minutes, as opposed to about 45 minutes required for the fabrication of the “keyhole” allograft structure.
Variations, modifications, and other uses of the present invention will become apparent to those skilled in the art, including the following, non-limiting examples: attachment of bone to bone; attachment of soft tissue to bone; non-medical applications. Thus, although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art.
The above description and drawings illustrate preferred embodiments which achieve the objects, features and advantages of the present invention. It is not intended that the present invention be limited to the illustrated embodiments. Any modification of the present invention which comes within the spirit and scope of the following claims should be considered part of the present invention.
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A meniscal allograft with a bone block having a trapezoidal shape in cross-section and a technique for using a meniscus allograft having a trapezoidal shaped bone block are disclosed. A groove is formed initially in the bone using drill bits. Dilators are used to increase the size of the drilled groove. The orthogonal corner at the bottom of the groove is shaped using a rasp. A smooth dilator compacts the bone in the acute angle at the bottom of the groove opposite the orthogonal corner to create the final trapezoid shape of the bone groove. A meniscal allograft having a bone block of corresponding trapezoidal shape is prepared using a workstation and three cutting jigs to make three corresponding cuts. The trapezoidal bone block of the meniscal allograft is then installed within the bone groove.
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TECHNICAL FIELD
[0001] The present invention relates to a working medium and a heat cycle system employing the working medium.
BACKGROUND ART
[0002] Heretofore, as a working medium for heat cycle such as a coolant for a refrigerator, a coolant for an air conditioner, a working fluid for power generation system (such as exhaust heat recovery power generation), a working medium for a latent heat transport apparatus (such as a heat pipe) or a secondary cooling medium, a chlorofluorocarbon (CFC) such as chlorotrifluoromethane or dichlorodifluoromethane or a hydrochlorofluorocarbon (HCFC) such as chlorodifluoromethane has been used. However, influences of CFCs and HCFCs over the ozone layer in the stratosphere have been pointed out, and their use are regulated at present.
[0003] Accordingly, as a working medium for heat cycle, a hydrofluorocarbon (HFC) which has less influence over the ozone layer, such as difluoromethane (HFC-32), tetrafluoroethane or pentafluoroethane, has been used. However, it is pointed out that HFCs may cause global warming. Accordingly, development of a working medium for heat cycle which has less influence over the ozone layer and has a low global warming potential is an urgent need.
[0004] For example, 1,1,1,2-tetrafluoroethane (HFC-134a) used as a coolant for an automobile air conditioner has a global warming potential so high as 1,430 (100 years). Further, in an automobile air conditioner, the coolant is highly likely to leak out to the air e.g. from a connection hose or a bearing.
[0005] As a coolant which replaces HFC-134a, carbon dioxide and 1,1-difluoroethane (HFC-152a) having a global warming potential of 124 (100 years) which is low as compared with HFC-134a, have been studied.
[0006] However, with carbon dioxide, the equipment pressure tends to be extremely high as compared with HFC-134a, and accordingly there are many problems to be solved in application to all the automobiles. HFC-152a has a range of inflammability, and has a problem for securing the safety.
[0007] As a working medium for heat cycle which has less influence over the ozone layer and has less influence over global warming, a hydrofluoroolefin (HFO) having a carbon-carbon double bond which is easily decomposed by OH radicals in the air is conceivable.
[0008] As a working medium for heat cycle comprising a HFO, for example, the following have been known.
[0009] (1) 3,3,3-Trifluoropropene (HFO-1243zf), 1,3,3,3-tetrafluoropropene (HFO-1234ze), 2-fluoropropene (HFO-1261yf), 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1,1,2-trifluoropropene (HFO-1243yc) (Patent Document 1).
[0010] (2) 1,2,3,3,3-Pentafluoropropene (HFO-1225ye), trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), cis-1,3,3,3-tetrafluoropropene (HFO-1234ze(Z)) and HFO-1234yf (Patent Document 2).
[0011] However, each of HFOs in (1) is insufficient in the cycle performance (capacity). Further, among HFOs in (1), one having a low proportion of fluorine atoms is combustible.
[0012] Each of HFOs in (2) is also insufficient in the cycle performance (capacity).
PRIOR ART DOCUMENTS
Patent Documents
[0013] Patent Document 1: JP-A-04-110388
[0014] Patent Document 2: JP-A-2006-512426
DISCLOSURE OF INVENTION
Technical Problem
[0015] The present invention provides a working medium for heat cycle, of which combustibility is suppressed, which has less influence over the ozone layer, which has less influence over global warming and which provides a heat cycle system excellent in the cycle performance (capacity), and a heat cycle system, of which the safety is secured, and which is excellent in the cycle performance (capacity).
Solution to Problem
[0016] The present invention provides a working medium for heat cycle (hereinafter sometimes referred to as working medium), which comprises 1,1,2-trifluoroethylene (hereinafter sometimes referred to as HFO-1123).
[0017] The working medium of the present invention preferably further contains a hydrocarbon.
[0018] The working medium of the present invention preferably further contains a HFC.
[0019] The working medium of the present invention preferably further contains a hydrochlorofluoroolefin (HCFO) or a chlorofluoroolefin (CFO).
[0020] The heat cycle system of the present invention employs the working medium of the present invention.
Advantageous Effects of Invention
[0021] The working medium of the present invention, which comprises HFO-1123 having a carbon-carbon double bond which is easily decomposed by OH radicals in the air, has less influence over the ozone layer and has less influence over global warming. Further, since it comprises HFO-1123, it provides a heat cycle system which is excellent in the cycle performance (capacity).
[0022] The heat cycle system of the present invention, which employs the working medium of the present invention excellent in the thermodynamic properties, is excellent in the cycle performance (capacity). Further, due to excellent capacity, downsizing of a system can be achieved.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a schematic construction view illustrating an example of a refrigerating cycle system.
[0024] FIG. 2 is a cycle diagram illustrating the state change of a working medium in a refrigerating cycle system on a temperature-entropy chart.
[0025] FIG. 3 is a cycle diagram illustrating the state change of a working medium in a refrigerating cycle system on a pressure-enthalpy chart.
DESCRIPTION OF EMBODIMENTS
<Working Medium>
[0026] The working medium of the present invention comprises 1,1,2-trifluoroethylene.
[0027] The working medium of the present invention may contain, as the case requires, another working medium which will be gasified or liquefied together with CFO1132, such as a hydrocarbon, a HFC, a HCFO or a CFO. Further, the working medium of the present invention may be used in combination with a component other than the working medium, used together with the working medium (hereinafter, a composition containing the working medium and a component other than the working medium will be referred to as a working medium-containing composition). The component other than the working medium may, for example, be a lubricating oil, a stabilizer, a leak detecting substance, a desiccating agent or other additives.
[0028] The content of HFO-1123 is preferably at least 60 mass %, more preferably at least 70 mass %, further preferably at least 80 mass %, particularly preferably 100 mass % in the working medium (100 mass %).
(Hydrocarbon)
[0029] The hydrocarbon is a working medium component which improves solubility of the working medium in a mineral lubricating oil.
[0030] The hydrocarbon has preferably from 3 to 5 carbon atoms, and may be linear or branched.
[0031] The hydrocarbon is specifically preferably propane, propylene, cyclopropane, butane, isobutane, pentane or isopentane.
[0032] The hydrocarbons may be used alone or in combination of two or more.
[0033] The content of the hydrocarbon is preferably from 1 to 40 mass %, more preferably from 2 to 10 mass %, in the working medium (100 mass %). When the content of the hydrocarbon is at least 1 mass %, the solubility of the lubricating oil in the working medium will sufficiently be improved. When the content of the hydrocarbon is at most 40 mass %, an effect to suppress combustibility of the working medium will be obtained.
(HFC)
[0034] The HFC is a working medium component which improves the cycle performance (capacity) of a heat cycle system.
[0035] The HFC is preferably a HFC which has less influence over the ozone layer and which has less influence over global warming.
[0036] The HFC has preferably from 1 to 5 carbon atoms, and may be linear or branched.
[0037] The HFC may, for example, be specifically difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane or heptafluorocyclopentane. Among them, particularly preferred is difluoromethane (HFC-32), 1,1-difluoroethane (HFC-152a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a) or pentafluoroethane (HFC-125), which has less influence over the ozone layer and which has less influence over global warming.
[0038] The HFCs may be used alone or in combination of two more.
[0039] The content of the HFC in the working medium (100 mass %) is preferably from 1 to 99 mass %, more preferably from 1 to 60 mass %. For example, in a case where the HFC is HFC-32, the coefficient of performance and the refrigerating capacity will be improved within a content range of from 1 to 99 mass %. In the case of HFC-134a, the coefficient of performance will be improved within a content range of from 1 to 99 mass %. In the case of HFC-125, the coefficient of performance and the refrigerating capacity may be decreased, but the decrease is not so remarkable. The HFC content can be controlled depending upon the required properties of the working medium.
(HCFO, CFO)
[0040] The HCFO and the CFO are working medium components which suppress combustibility of the working medium. Further, they are components which improve the solubility of the lubricating oil in the working medium.
[0041] As the HCFO and the CFO, preferred is a HCFO which has less influence over the ozone layer and which has less influence over global warming.
[0042] The HCFO has preferably from 2 to 5 carbon atoms, and may be linear or branched.
[0043] The HCFO may, for example, be specifically hydrochlorofluoropropene or hydrochlorofluoroethylene. Among them, particularly preferred is 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) or 1-chloro-1,2-difluoroethylene (HCFO-1122), with a view to sufficiently suppressing combustibility of the working medium without substantially decreasing the cycle performance (capacity) of the heat cycle system.
[0044] The HCFOs may be used alone or in combination of two or more.
[0045] The CFO has preferably from 2 to 5 carbon atoms, and may be linear or branched.
[0046] The CFO may, for example, be specifically chlorofluoropropene or chlorofluoroethylene. Among them, particularly preferred is 1,1-dichloro-2,3,3,3-tetrafluoropropene (CFO-1214ya) or 1,2-dichloro-1,2-difluoroethylene (CFO-1112) with a view to sufficiently suppressing combustibility of the working medium without substantially decreasing the cycle performance (capacity) of the heat cycle system.
[0047] The total content of the HCFO and the CFO is preferably from 1 to 60 mass % in the working medium (100 mass %). Chlorine atoms have an effect to suppress combustibility, and by addition of the HCFO and the CFO, it is possible to sufficiently suppress combustibility of the working medium without substantially decreasing the cycle performance (capacity) of the heat cycle system.
(Lubricating Oil)
[0048] As the lubricating oil to be used for the working medium-containing composition, a known lubricating oil used for the heat cycle system may be used.
[0049] The lubricating oil may, for example, be an oxygen-containing synthetic oil (such as an ester lubricating oil or an ether lubricating oil), a fluorinated lubricating oil, a mineral oil or a hydrocarbon synthetic oil.
[0050] The ester lubricating oil may, for example, be a dibasic acid ester oil, a polyol ester oil, a complex ester oil or a polyol carbonate oil.
[0051] The dibasic acid ester oil is preferably an ester of a C 5-10 dibasic acid (such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid or sebacic acid) with a C 1-15 monohydric alcohol which is linear or has a branched alkyl group (such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol or pentadecanol). Specifically, ditridecyl glutarate, di(2-ethylhexyl) adipate, diisodecyl adipate, ditridecyl adipate or di(3-ethylhexyl) sebacate may, for example, be mentioned.
[0052] The polyol ester oil is preferably an ester of a diol (such as ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butandiol, 1,5-pentadiol, neopentyl glycol, 1,7-heptanediol or 1,12-dodecanediol) or a polyol having from 3 to 20 hydroxy groups (such as trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, glycerol, sorbitol, sorbitan or sorbitol/glycerin condensate) with a C 6-20 fatty acid (such as a linear or branched fatty acid such as hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, eicosanoic acid or oleic acid, or a so-called neo acid having a quaternary a carbon atom).
[0053] The polyol ester oil may have a free hydroxy group.
[0054] The polyol ester oil is preferably an ester (such as trimethylolpropane tripelargonate, pentaerythritol 2-ethylhexanoate or pentaerythritol tetrapelargonate) of a hindered alcohol (such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane or pentaerythritol).
[0055] The complex ester oil is an ester of a fatty acid and a dibasic acid, with a monohydric alcohol and a polyol. The fatty acid, the dibasic acid, the monohydric alcohol and the polyol may be as defined above.
[0056] The polyol carbonate oil is an ester of carbonic acid with a polyol.
[0057] The polyol may be the above-described diol or the above-described polyol. Further, the polyol carbonate oil may be a ring-opening polymer of a cyclic alkylene carbonate.
[0058] The ether lubricating oil may be a polyvinyl ether oil or a polyoxyalkylene lubricating oil.
[0059] The polyvinyl ether oil may be one obtained by polymerizing a vinyl ether monomer such as an alkyl vinyl ether, or a copolymer obtained by copolymerizing a vinyl ether monomer and a hydrocarbon monomer having an olefinic double bond.
[0060] The vinyl ether monomers may be used alone or in combination of two or more.
[0061] The hydrocarbon monomer having an olefinic double bond may, for example, be ethylene, propylene, various forms of butene, various forms of pentene, various forms of hexene, various forms of heptene, various forms of octene, diisobutylene, triisobutylene, styrene, a-methylstyrene or alkyl-substituted styrene. The hydrocarbon monomers having an olefinic double bond may be used alone or in combination of two or more.
[0062] The polyvinyl ether copolymer may be either of a block copolymer and a random copolymer.
[0063] The polyvinyl ethers may be used alone or in combination of two or more.
[0064] The polyoxyalkylene lubricating oil may, for example, be a polyoxyalkylene monool, a polyoxyalkylene polyol, an alkyl ether of a polyoxyalkylene monool or a polyoxyalkylene polyol, or an ester of a polyoxyalkylene monool or a polyoxyalkylene polyol. The polyoxyalkylene monool or the polyoxyalkylene polyol may be one obtained by e.g. a method of subjecting a C 2-4 alkylene oxide (such as ethylene oxide or propylene oxide) to ring-opening addition polymerization to an initiator such as water or a hydroxy group-containing compound in the presence of a catalyst such as an alkali hydroxide. Further, one molecule of the polyoxyalkylene chain may contain single oxyalkylene units or two or more types of oxyalkylene units. It is preferred that at least oxypropylene units are contained in one molecule.
[0065] The initiator may, for example, be water, a monohydric alcohol such as methanol or butanol, or a polyhydric alcohol such as ethylene glycol, propylene glycol, pentaerythritol or glycerol.
[0066] The polyoxyalkylene lubricating oil is preferably an alkyl ether or an ester of a polyoxyalkylene monool or polyoxyalkylene polyol. Further, the polyoxyalkylene polyol is preferably a polyoxyalkylene glycol. Particularly preferred is an alkyl ether of a polyoxyalkylene glycol having the terminal hydroxy group of the polyoxyalkylene glycol capped with an alkyl group such as a methyl group, which is called a polyglycol oil.
[0067] The fluorinated lubricating oil may, for example, be a compound having hydrogen atoms of a synthetic oil (such as the after-mentioned mineral oil, poly-α-olefin, alkylbenzene or alkylnaphthalene) substituted by fluorine atoms, a perfluoropolyether oil or a fluorinated silicone oil.
[0068] The mineral oil may, for example, be a naphthene mineral oil or a paraffin mineral oil obtained by purifying a lubricating oil fraction obtained by atmospheric distillation or vacuum distillation of crude oil by a purification treatment (such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrotreating or clay treatment) optionally in combination.
[0069] The hydrocarbon synthetic oil may, for example, be a poly-α-olefin, an alkylbenzene or an alkylnaphthalene.
[0070] The lubricating oils may be used alone or in combination of two or more.
[0071] The lubricating oil is preferably a polyol ester oil and/or a polyglycol oil in view of the compatibility with the working medium, particularly preferably a polyalkylene glycol oil with a view to obtaining a remarkable antioxidant effect by a stabilizer.
[0072] The content of the lubricating oil is not limited within a range not to remarkably decrease the effects of the present invention, varies depending upon e.g. the application and the form of a compressor, and is preferably from 10 to 100 parts by mass, more preferably from 20 to 50 parts by mass based on the working medium (100 parts by mass).
(Stabilizer)
[0073] The stabilizer to be used for the working medium-containing composition is a component which improves the stability of the working medium against heat and oxidation.
[0074] The stabilizer may, for example, be an oxidation resistance-improving agent, a heat resistance-improving agent or a metal deactivator.
[0075] The oxidation resistance-improving agent and the heat resistance-improving agent may, for example, be N,N′-diphenylphenylenediamine, p-octyldiphenylamine, p,p′-dioctyldiphenylamine, N-phenyl-1-naphthyamine, N-phenyl-2-naphthylamine, N-(p-dodecyl)phenyl-2-naphthylamine, di-1-naphthylamine, di-2-naphthylamine, N-alkylphenothiazine, 6-(t-butyl)phenol, 2,6-di-(t-butyl)phenol, 4-methyl-2,6-di-(t-butyl)phenol or 4,4′-methylenebis(2,6-di-t-butylphenol). The oxidation resistance-improving agents and the heat resistance-improving agents may be used alone or in combination of two or more.
[0076] The metal deactivator may, for example, be imidazole, benzimidazole, 2-mercaptobenzothiazole, 2,5-dimercaptothiadiazole, salicylysine-propylenediamine, pyrazole, benzotriazole, tritriazole, 2-methylbenzamidazole, 3,5-dimethylpyrazole, methylenebis-benzotriazole, an organic acid or an ester thereof, a primary, secondary or tertiary aliphatic amine, an amine salt of an organic acid or inorganic acid, a heterocyclic nitrogen-containing compound, an amine salt of an alkyl phosphate, or a derivative thereof.
[0077] The content of the stabilizer is not limited within a range not to remarkably decrease the effects of the present invention, and is preferably at most 5 mass %, more preferably at most 1 mass % in the working medium-containing composition (100 mass %).
(Leak Detecting Substance)
[0078] The leak detecting substance to be used for the working medium-containing composition may, for example, be an ultraviolet fluorescent dye, an odor gas or an odor masking agent.
[0079] The ultraviolet fluorescent dye may be known ultraviolet fluorescent dyes as disclosed in e.g. U.S. Pat. No. 4,249,412, JP-A-10-502737, JP-A-2007-511645, JP-A-2008-500437 and JP-A-2008-531836.
[0080] The odor masking agent may be known perfumes as disclosed in e.g. JP-A-2008-500437 and JP-A-2008-531836.
[0081] In a case where the leak detecting substance is used, a solubilizing agent which improves the solubility of the leak detecting substance in the working medium may be used.
[0082] The solubilizing agent may be ones as disclosed in e.g. JP-A-2007-511645, JP-A-2008-500437 and JP-A-2008-531836.
[0083] The content of the leak detecting substance is not particularly limited within a range not to remarkably decrease the effects of the present invention, and is preferably at most 2 mass %, more preferably at most 0.5 mass % in the working medium-containing composition (100 mass %).
(Other Compound)
[0084] The working medium of the present invention and the working medium-containing composition may contain a C 1-4 alcohol or a compound used as a conventional working medium, coolant or heat transfer medium (hereinafter the alcohol and the compound will generally be referred to as other compound).
[0085] As such other compound, the following compounds may be mentioned.
[0086] Fluorinated ether: Perfluoropropyl methyl ether (C 3 F 7 OCH 3 ), perfluorobutyl methyl ether (C 4 F 9 OCH 3 ), perfluorobutyl ethyl ether (C 4 F 9 OC 2 H 5 ), 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (CF 2 HCF 2 OCH 2 CF 3 , manufactured by Asahi Glass Company, Limited, AE-3000), etc.
[0087] The content of such other compound is not limited within a range not to remarkably decrease the effects of the present invention, and is preferably at most 30 mass %, more preferably at most 20 mass %, particularly preferably at most 15 mass % in the working medium-containing composition (100 mass %).
<Heat Cycle System>
[0088] The heat cycle system of the present invention is a system employing the working medium of the present invention.
[0089] The heat cycle system may, for example, be a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system or a heat transport system.
(Refrigerating Cycle System)
[0090] As an example of the heat cycle system, a refrigerating cycle system will be described.
[0091] The refrigerating cycle system is a system wherein in an evaporator, a working medium removes heat energy from a load fluid to cool the load fluid thereby to accomplish cooling to a lower temperature.
[0092] FIG. 1 is a schematic construction view illustrating an example of a refrigerating cycle system of the present invention. A refrigerating cycle system 10 is a system generally comprising a compressor 11 to compress a working medium vapor A to form a high temperature/high pressure working medium vapor B, a condenser 12 to cool and liquefy the working medium vapor B discharged from the compressor 11 to form a low temperature/high pressure working medium C, an expansion valve 13 to let the working medium C discharged from the condenser 12 expand to form a low temperature/low pressure working medium D, an evaporator 14 to heat the working medium D discharged from the expansion valve 13 to form a high temperature/low pressure working medium vapor A, a pump 15 to supply a load fluid E to the evaporator 14 , and a pump 16 to supply a fluid F to the condenser 12 .
[0093] In the refrigerating cyclic system 10 , the following cycle is repeated.
[0094] (i) A working medium vapor A discharged from an evaporator 14 is compressed by a compressor 11 to form a high temperature/high pressure working medium vapor B.
[0095] (ii) The working medium vapor B discharged from the compressor 11 is cooled and liquefied by a fluid F in a condenser 12 to form a low temperature/high pressure working medium C. At that time, the fluid F is heated to form a fluid F′, which is discharged from the condenser 12 .
[0096] (iii) The working medium C discharged from the condenser 12 is expanded in an expansion valve 13 to form a low temperature/low pressure working medium D.
[0097] (iv) The working medium D discharged from the expansion valve 13 is heated by a load fluid E in an evaporator 14 to form a high temperature/low pressure working medium vapor A. At that time, the load fluid E is cooled and becomes a load fluid E′, which is discharged from the evaporator 14 .
[0098] The refrigerating cycle system 10 is a cycle comprising an adiabatic isentropic change, an isenthalpic change and an isobaric change, and the state change of the working medium may be shown as in FIG. 2 , when it is represented on a temperature-entropy chart.
[0099] In FIG. 2 , the AB process is a process wherein adiabatic compression is carried out by the compressor 11 to change the high temperature/low pressure working medium vapor A to a high temperature/high pressure working medium vapor B. The BC process is a process wherein isobaric cooling is carried out in the condenser 12 to change the high temperature/high pressure working medium vapor B to a low temperature/high pressure working medium C. The CD process is a process wherein isenthalpic expansion is carried out by the expansion valve 13 to change the low temperature/high pressure working medium C to a low temperature/low pressure working medium D. The DA process is a process wherein isobaric heating is carried out in the evaporator 14 to have the low temperature/low pressure working medium D returned to a high temperature/low pressure working medium vapor A.
[0100] In the same manner, the state change of the working medium may be shown as in FIG. 3 , when it is represented on a pressure-enthalpy chart.
(Moisture Concentration)
[0101] There is a problem of inclusion of moisture in the heat cycle system. Inclusion of moisture may cause freezing in a capillary tube, hydrolysis of the working medium or the lubricating oil, deterioration of materials by an acid component formed in heat cycle, formation of contaminants, etc. Particularly, the above-described ether lubricating oil, ester lubricating oil and the like have extremely high moisture absorbing properties and are likely to undergo hydrolysis, and inclusion of moisture decreases properties of the lubricating oil and may be a great cause to impair the long term reliability of a compressor. Further, in an automobile air conditioner, moisture tends to be included from a coolant hose or a bearing of a compressor used for the purpose of absorbing vibration. Accordingly, in order to suppress hydrolysis of the lubricating oil, it is necessary to suppress the moisture concentration in the heat cycle system. The moisture concentration of the working medium in the heat cycle system is preferably at most 100 ppm, more preferably at most 20 ppm.
[0102] As a method of suppressing the moisture concentration in the heat cycle system, a method of using a desiccating agent (such as silica gel, activated aluminum or zeolite) may be mentioned. The desiccating agent is preferably a zeolite desiccating agent in view of chemical reactivity of the desiccating agent and the working medium, and the moisture absorption capacity of the desiccating agent.
[0103] The zeolite desiccating agent is, in a case where a lubricating oil having a large moisture absorption as compared with a conventional mineral lubricating oil is used, preferably a zeolite desiccating agent containing a compound represented by the following formula (1) as the main component in view of excellent moisture absorption capacity.
[0000] M 2/n O.Al 2 O 3 .xSiO 2 .yH 2 O (1)
[0000] wherein M is a group 1 element such as Na or K or a group 2 element such as Ca, n is the valence of M, and x and y are values determined by the crystal structure. The pore size can be adjusted by changing M.
[0104] To select the desiccating agent, the pore size and the fracture strength are important.
[0105] In a case where a desiccating agent having a pore size larger than the molecular size of the working medium is used, the working medium is adsorbed in the desiccating agent and as a result, chemical reaction between the working medium and the desiccating agent will occur, thus leading to undesired phenomena such as formation of non-condensing gas, a decrease in the strength of the desiccating agent, and a decrease in the adsorption capacity.
[0106] Accordingly, it is preferred to use as the desiccating agent a zeolite desiccating agent having a small pore size. Particularly preferred is sodium/potassium type A synthetic zeolite having a pore size of at most 3.5 Å. By using a sodium/potassium type A synthetic zeolite having a pore size smaller than the molecular size of the working medium, it is possible to selectively adsorb and remove only moisture in the heat cycle system without adsorbing the working medium. In other words, the working medium is less likely to be adsorbed in the desiccating agent, whereby heat decomposition is less likely to occur and as a result, deterioration of materials constituting the heat cycle system and formation of contaminants can be suppressed.
[0107] The size of the zeolite desiccating agent is preferably from about 0.5 to about 5 mm, since if it is too small, a valve or a thin portion in pipelines may be clogged, and if it is too large, the drying capacity will be decreased. Its shape is preferably granular or cylindrical.
[0108] The zeolite desiccating agent may be formed into an optional shape by solidifying powdery zeolite by a binding agent (such as bentonite). So long as the desiccating agent is composed mainly of the zeolite desiccating agent, other desiccating agent (such as silica gel or activated alumina) may be used in combination.
[0109] The proportion of the zeolite desiccating agent based on the working medium is not particularly limited.
(Chlorine Concentration)
[0110] If chlorine is present in the heat cycle system, it has adverse effects such as formation of a deposit by reaction with a metal, abrasion of the bearing, and decomposition of the working medium or the lubricating oil.
[0111] The chlorine concentration in the heat cycle system is preferably at most 100 ppm, particularly preferably at most 50 ppm by the mass ratio based on the working medium.
(Non-Condensing Gas Concentration)
[0112] If non-condensing gas is included in the heat cycle system, it has adverse effects such as heat transfer failure in the condenser or the evaporator and an increase in the working pressure, and it is necessary to suppress its inclusion as far as possible. Particularly, oxygen which is one of non-condensing gases reacts with the working medium or the lubricating oil and promotes their decomposition.
[0113] The non-condensing gas concentration is preferably at most 1.5 vol %, particularly preferably at most 0.5 vol % by the volume ratio based on the working medium, in a gaseous phase of the working medium.
EXAMPLES
[0114] Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.
(Evaluation of Refrigerating Cycle Performance)
[0115] The refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) was evaluated as the cycle performance (the capacity and the efficiency) in a case where a working medium was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0116] Evaluation was carried out by setting the average evaporation temperature of the working medium in an evaporator 14 , the average condensing temperature of the working medium in a condenser 12 , the supercooling degree of the working medium in the condenser 12 , and the degree of superheat of the working medium in the evaporator 14 , respectively. Further, it was assumed that there was no pressure loss in the equipment efficiency and in the pipelines and heat exchanger.
[0117] The refrigerating capacity Q and the coefficient of performance η are obtained from the following formulae (2) and (3) using the enthalpy h in each state (provided that a suffix attached to h indicates the state of the working medium).
[0000] Q=h A −h D (2)
[0000] η=refrigerating capacity/compression work=( h A −h D )/( h B −h A ) (3)
[0118] The coefficient of performance means the efficiency in the refrigerating cycle system, and a higher coefficient of performance means that a higher output (refrigerating capacity) can be obtained by a smaller input (electric energy required to operate a compressor).
[0119] Further, the refrigerating capacity means a capacity to cool a load fluid, and a higher refrigerating capacity means that more works can be done in the same system. In other words, it means that with a working medium having a larger refrigerating capacity, the desired performance can be obtained with a smaller amount, whereby the system can be downsized.
[0120] The thermodynamic properties required for calculation of the refrigerating cycle performance were calculated based on the generalized equation of state (Soave-Redlich-Kwong equation) based on the law of corresponding state and various thermodynamic equations. If a characteristic value was not available, it was calculated employing an estimation technique based on a group contribution method.
Example 1
[0121] The refrigerating cycler performance (the refrigerating capacity and the coefficient of performance) was evaluated in a case where a working medium comprising HFO-1123 and a HFC as identified in Table 1 was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0122] Evaluation was carried out by setting the average evaporation temperature of the working medium in an evaluator 14 to be 0° C., the average condensing temperature of the working medium in a condenser 12 to be 50° C., the supercooling degree of the working medium in the condenser 12 to be 5° C., and the degree of superheat of the working medium in the evaporator 14 to be 5° C.
[0123] Based on the refrigerating cycle performance of HFC-134a, the relative performance (each working medium/HFC-134a) of the refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) of each working medium based on HFC-134a was obtained. The results of each working medium are shown in Table 1.
[0000]
TABLE 1
Relative performance
Relative performance
Relative performance
(based on HFC-134a)
(based on HFC-134a)
(based on HFC-134a)
[—]
[—]
[—]
Coefficient
Refriger-
Coefficient
Refriger-
Coefficient
Refriger-
HFO-1123
HFC-125
of
ating
HFO-1123
HFC-134a
of
ating
HFO-1123
HFC-32
of
ating
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
0
100
0.795
1.517
0
100
1.000
1.000
0
100
0.918
2.518
20
80
0.787
1.693
20
80
0.966
1.262
20
80
0.899
2.540
40
60
0.800
1.841
40
60
0.935
1.502
40
60
0.883
2.521
60
40
0.825
1.957
60
40
0.908
1.718
60
40
0.872
2.444
80
20
0.857
2.034
80
20
0.894
1.915
80
20
0.872
2.297
100
0
0.888
2.070
100
0
0.888
2.070
100
0
0.888
2.070
[0124] From the results in Table 1, it was confirmed that the coefficient of performance and the refrigerating capacity of HFO-1123 were improved by adding HFC-32 to HFO-1123. By addition of HFC-134a, the coefficient of performance was improved. By addition of HFC-125, the coefficient of performance and the refrigerating capacity were decreased, but a refrigerating capacity of at least 1.0 was maintained. It is considered that HFC-125, which has an excellent effect to suppress combustibility and can sufficiently suppress combustibility of a working medium, is effective when the working medium is required to suppress combustibility.
Example 2
[0125] The refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) was evaluated in a case where a working medium comprising HFO-1123 and a HFC as identified in Table 2 or 3 was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0126] Evaluation was carried out by setting the average evaporation temperature of the working medium in an evaporator 14 to be 0° C., the average condensing temperature of the working medium in a condenser 12 to be 50° C., the supercooling degree of the working medium in the condenser 12 to be 5° C., and the degree of superheat of the working medium in the evaporator 14 to be 5° C.
[0127] Based on the refrigerating cycle performance of HFC-134a in Example 1, the relative performance (each working medium/HFC-134a) of the refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) of each working medium based on HFC-134a was obtained. The results of each working medium are shown in Tables 2 and 3.
[0000]
TABLE 2
Relative performance
Relative performance
(based on HFC-134a)
(based on HFC-134a)
[—]
[—]
HFO-1123
HFO-1225ye(E)
Coefficient of
Refrigerating
HFO-1123
HFO-1225ye(Z)
Coefficient of
Refrigerating
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
0
100
1.024
0.663
0
100
1.005
0.767
20
80
0.998
0.990
20
80
0.978
1.090
40
60
0.968
1.294
40
60
0.948
1.378
60
40
0.927
1.563
60
40
0.916
1.631
80
20
0.902
1.830
80
20
0.898
1.869
100
0
0.888
2.070
100
0
0.888
2.070
[0000]
TABLE 3
Relative performance
Relative performance
(based on HFC-134a)
(based on HFC-134a)
[—]
[—]
HFO-1123
HFO-1234ze(E)
Coefficient of
Refrigerating
HFO-1123
HFO-1243zf
Coefficient of
Refrigerating
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
0
100
0.996
0.752
0
100
0.995
0.978
20
80
0.972
1.043
20
80
0.977
1.190
40
60
0.946
1.325
40
60
0.956
1.407
60
40
0.914
1.584
60
40
0.932
1.625
80
20
0.895
1.841
80
20
0.908
1.847
100
0
0.888
2.070
100
0
0.888
2.070
[0128] From the results in Tables 2 and 3, it was confirmed that HFO-1123 has a high refrigerating capacity as compare with a conventional HFO. Further, it was confirmed that by addition of the HFO, the coefficient of performance could be improved without a remarkable decrease of the refrigerating capacity.
Example 3
[0129] The refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) was evaluated in a case where a working medium comprising HFO-1123 and a hydrocarbon as identified in Table 4 was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0130] Evaluation was carried out by setting the average evaporation temperature of the working medium in an evaporator 14 to be 0° C., the average condensing temperature of the working medium in a condenser 12 to be 50° C., the supercooling degree of the working medium in the condenser 12 to be 5° C., and the degree of superheat of the working medium in the evaporator 14 to be 5° C.
[0131] Based on the refrigerating cycle performance of HFC-134a in Example 1, the relative performance (each working medium/HFC-134a) of the refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) of each working medium based on HFC-134a was obtained. The results of each working medium are shown in Table 4.
[0000]
TABLE 4
Relative performance
Relative performance
Relative performance
(based on HFC-134a)
(based on HFC-134a)
(based on HFC-134a)
[—]
[—]
[—]
Coefficient
Refriger-
Coefficient
Refriger-
Coefficient
Refriger-
HFO-1123
Propane
of
ating
HFO-1123
Butane
of
ating
HFO-1123
Isobutane
of
ating
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
0
100
0.977
1.340
0
100
1.065
0.393
0
100
1.038
0.540
20
80
0.965
1.446
20
80
1.047
0.537
20
80
1.027
0.700
40
60
0.950
1.571
40
60
1.059
0.745
40
60
1.027
0.913
60
40
0.930
1.718
60
40
1.047
1.020
60
40
1.006
1.182
80
20
0.907
1.888
80
20
0.974
1.382
80
20
0.947
1.528
90
10
0.896
1.980
90
10
0.923
1.653
90
10
0.915
1.770
92
8
0.894
1.998
92
8
0.914
1.724
92
8
0.910
1.827
94
6
0.892
2.016
94
6
0.907
1.801
94
6
0.905
1.886
96
4
0.891
2.034
96
4
0.900
1.886
96
4
0.899
1.947
98
2
0.889
2.052
98
2
0.894
1.976
98
2
0.894
2.008
100
0
0.888
2.070
100
0
0.888
2.070
100
0
0.888
2.070
[0132] From the results in Table 4, it was confirmed that the coefficient of performance of HFO-1123 could be improved without a remarkable decrease of the refrigerating capacity by adding a hydrocarbon to HFO-1123.
Example 4
[0133] The refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) was evaluated in a case where a working medium comprising HFO-1123 and a HCFO as identified in Table 5 was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0134] Evaluation was carried out by setting the average evaporation temperature of the working medium in an evaporator 14 to be 0° C., the average condensing temperature of the working medium in a condenser 12 to be 50° C., the supercooling degree of the working medium in the condenser 12 to be 5° C., and the degree of superheat of the working medium in the evaporator 14 to be 5° C.
[0135] Based on the refrigerating cycle performance of HFC-134a in Example 1, the relative performance (each working medium/HFC-134a) of the refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) of each working medium based on HFC-134a was obtained. The results of each working medium are shown in Table 5.
[0000]
TABLE 5
Relative performance
Relative performance
(based on HFC-134a)
(based on HFC-134a)
[—]
[—]
HFO-1123
HCFO-1224yd
Coefficient of
Refrigerating
HFO-1123
HCFO-1122
Coefficient of
Refrigerating
[mass %]
[mass %]
performance
capacity
[mass %]
[mass %]
performance
capacity
0
100
1.061
0.357
0
100
1.099
0.526
20
80
1.044
0.697
20
80
1.068
0.769
40
60
1.030
1.043
40
60
1.049
1.039
60
40
0.961
1.337
60
40
1.004
1.323
80
20
0.902
1.667
80
20
0.942
1.647
90
10
0.893
1.870
90
10
0.912
1.842
92
8
0.893
1.912
92
8
0.907
1.885
94
6
0.892
1.953
94
6
0.902
1.929
96
4
0.891
1.994
96
4
0.897
1.975
98
2
0.890
2.032
98
2
0.893
2.022
100
0
0.888
2.070
100
0
0.888
2.070
[0136] From the results in Table 5, it was confirmed that the coefficient of performance of HFO-1123 could be improved without a remarkable decrease of the refrigerating capacity by adding a HCFO to HFO-1123.
Example 5
[0137] The refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) was evaluated in a case where HFO-1123 as a working medium was applied to a refrigerating cycle system 10 shown in FIG. 1 .
[0138] The evaporation temperature of the working medium in an evaporator 14 , the condensing temperature of the working medium in a condenser 12 , the supercooling degree of the working medium in the condenser 12 and the degree of superheat of the working medium in the evaporator 14 were temperatures as identified in Table 6.
[0139] Based on the refrigerating cycle performance of HFC-134a in Example 1, the relative performance (HFO-1123/HFC-134a) of the refrigerating cycle performance (the refrigerating capacity and the coefficient of performance) of HFO-1123 based on HFC-134a was obtained. The results are shown in Table 6.
[0000]
TABLE 6
Relative performance
(based on HFC-134a)
Degree
[—]
of
Super-
HFO-1123
Evaporation
Condensing
super-
cooling
Coefficient
Refriger-
temperature
temperature
heat
degree
of
ating
[° C.]
[° C.]
[° C.]
[° C.]
performance
capacity
−40
10
5
5
0.962
2.987
−30
20
5
5
0.953
2.710
−20
30
5
5
0.939
2.475
−10
40
5
5
0.919
2.266
0
50
5
5
0.888
2.070
10
60
5
5
0.842
1.868
INDUSTRIAL APPLICABILITY
[0140] The working medium of the present invention is useful as a working medium for heat cycle such as a coolant for a refrigerator, a coolant for an air conditioner, a working fluid for power generation system (such as exhaust heat recovery power generation), a working medium for a latent heat transport apparatus (such as a heat pipe) or a secondary cooling medium.
[0141] This application is a continuation of PCT Application No. PCT/JP2012/062843, filed on May 18, 2012, which is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-112417 filed on May 19, 2011. The contents of those applications are incorporated herein by reference in its entirety.
REFERENCE SYMBOL
[0142] 10 : Refrigerating cycle system
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To provide a working medium for heat cycle, of which combustibility is suppressed, which has less influence over the ozone layer, which has less influence over global warming and which provides a heat cycle system excellent in the cycle performance (capacity), and a heat cycle system, of which the safety is secured, and which is excellent in the cycle performance (capacity).
A working medium for heat cycle comprising 1,1,2-trifluoroethylene is employed for a heat cycle system (such as a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system 10 or a heat transport system).
| 5
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RELATED APPLICATIONS
[0001] This is a Continuation of the National Stage Designation of PCT/IL00/00093, filed Feb. 20, 2000.
FIELD OF THE INVENTION
[0002] This invention relates generally to a cutting tool and more particularly to a ball nose end mill, and an arrangement for retaining a replaceable cutting insert therein, especially an indexable cutting insert.
BACKGROUND OF THE INVENTION
[0003] In conventional ball nose end mills cutting inserts are clamped in position by a retaining screw. A problem with this arrangement is that the accuracy of the initial location of the cutting edge of a cutting insert retained in the end mill is dependent on the accuracy with which the retaining screw is located in the end mill. Any play or clearance between the screw and the cutting insert results in a corresponding inaccuracy in the location of the cutting edge of the cutting insert.
[0004] A solution to this problem is proposed in U.S. Pat. No. 4,883,391, in accordance with which a clamping screw is provided with a cylindrical portion which is held in engagement with a cylindrical bore portion in the end mill. However, this solution calls for both a very accurately manufactured cylindrical portion on the screw and a correspondingly very accurately manufactured cylindrical bore portion in the end mill. Both of these requirements increase the cost of manufacture of the end mill as a whole. Furthermore, any inaccuracies introduced into these two cylindrical elements during use of the end mill, will introduce a corresponding inaccuracy in the location of the cutting edge of the cutting insert.
SUMMARY OF THE INVENTION
[0005] In accordance with the present invention there is provided a cutting tool assembly comprising cutting insert holder and a cutting insert, the cutting insert holder comprising a clamping portion, at a front portion thereof, connected to a body portion;
[0006] the clamping portion comprising:
[0007] a lower clamping jaw having a lower peripheral surface and an upper surface;
[0008] an upper clamping jaw resiliently connected to the lower clamping jaw, the upper clamping jaw having a lower surface and an upper peripheral surface, the lower surface being provided with two elongated spaced apart substantially parallel grooves;
[0009] a through bore passing through the upper and lower clamping jaws, the through bore being internally threaded in one of the upper or lower clamping jaws; and
[0010] an insert receiving slot defined between the upper and lower clamping jaws;
[0011] the cutting insert comprising:
[0012] an upper surface provided with two elongated spaced apart substantially parallel ridges;
[0013] a lower surface;
[0014] a peripheral side surface between the upper surface and the lower surface, the peripheral side surface being provided with at least one cutting edge;
[0015] a rake surface associated with the at least one cutting edge; and
[0016] a through bore passing through the cutting insert, from the upper surface to the lower surface;
[0017] wherein the cutting insert is retained in the insert receiving slot in a retained position by means of a screw which passes through the through bore in the upper and lower jaws of the insert holder and through the through bore in the cutting insert, and wherein in the retained position at least a portion of the lower surface of the cutting insert abuts at least a portion of the upper surface of the lower clamping jaw and the two elongated ridges in the upper surface of the cutting insert cooperate with the two elongated parallel grooves in the lower surface of the upper clamping jaw.
[0018] In accordance with a preferred embodiment of the present invention, the cutting insert is provided with at least one elongated recess in the lower surface of the cutting insert in a portion of the peripheral side surface, and the upper surface of the lower clamping jaw is provided with an insert location surface and at least a portion of a substantially upright surface of the at least one elongated recess in the lower surface of the cutting insert abuts the insert location surface in the upper surface of the lower clamping jaw.
[0019] Also in accordance with the present invention there is provided a cutting insert comprising:
[0020] an upper surface provided with two elongated spaced apart substantially parallel ridges;
[0021] a lower surface;
[0022] a side peripheral surface between the upper surface and the lower surface, the peripheral surface being provided with at least one cutting edge;
[0023] a rake surface associated with the at least one cutting edge; and
[0024] a through bore passing through the cutting insert, from the upper surface to the lower surface.
[0025] Also in accordance with a preferred embodiment, the lower surface of the cutting insert is provided with at least one elongated recess in a portion of the peripheral side surface.
[0026] In accordance with a preferred embodiment of the present invention, the two elongated grooves in the lower surface of the upper clamping jaw are located adjacent to and on either side of the through bore in the upper clamping jaw.
[0027] Further in accordance with a preferred embodiment of the present invention, the two elongated ridges in the upper surface of the cutting insert are located adjacent to and on either side of the through bore in the cutting insert
[0028] Still further in accordance with a preferred embodiment of the present invention, each of the two elongated ridges in the upper surface of the cutting insert have an indentation in a portion thereof.
[0029] Yet still further in accordance with a preferred embodiment of the present invention, the indentation is in a region adjacent the through bore in the cutting insert.
[0030] In accordance with one specific application, the cutting insert is generally oval in shape in a top view and is provided with two diametrically opposite sets of cutting edges.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] For a better understanding the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0032] [0032]FIG. 1 is a perspective view of a cutting tool assembly according to the present invention;
[0033] [0033]FIG. 2 is a perspective view of the front portion of the cutting tool assembly of FIG. 1;
[0034] [0034]FIG. 3 is an exploded view of the cutting tool assembly of FIG. 2;
[0035] [0035]FIG. 4 is a perspective view of the cutting insert holder according to the present invention;
[0036] [0036]FIG. 5 is a bottom perspective view of the cutting insert holder of FIG. 4 with the lower clamping jaw removed for clarification purposes;
[0037] [0037]FIG. 6 is a top perspective view of the cutting insert holder of FIG. 4 with the upper clamping jaw removed for clarification purposes;
[0038] [0038]FIG. 7 is a top perspective view of the cutting insert according to the present invention;
[0039] [0039]FIG. 8 is a bottom perspective view of the cutting insert according to the present invention;
[0040] [0040]FIG. 9 is a top view of the cutting insert according to the present invention;
[0041] [0041]FIG. 10 is a bottom view of the cutting insert according to the present invention;
[0042] [0042]FIG. 11 is a side view of the cutting tool assembly of FIG. 2;
[0043] [0043]FIG. 12 is a view of the cutting tool assembly of FIG. 2 in a direction along a line parallel to and passing between the grooves in the upper clamping jaw;
[0044] [0044]FIG. 13 is an enlarged cross sectional view of the cutting tool assembly of FIG. 2 taken in a plane passing through and perpendicular to the ridges in the upper surface of the cutting insert, showing the relative position between the cutting insert and the clamping portion prior to tightening the screw, which is not shown for the sake of clarification;
[0045] [0045]FIG. 14 is a cross sectional view of the cutting tool assembly as in FIG. 13 but showing the situation in the first stage of tightening the screw;
[0046] [0046]FIG. 15 is an enlarged detail of the circled portion in FIG. 14; and
[0047] [0047]FIG. 16 is a cross sectional view of the cutting tool assembly as in FIG. 13 but showing the situation in the final stage of tightening the screw.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Attention is first drawn to FIGS. 1 to 6 . As shown, a cutting tool assembly 10 having an axis of rotation A comprises a cutting insert holder 12 and a cutting insert 14 mounted therein and secured by a screw 15 . The cutting insert holder 12 comprises an elongated cylindrical body portion 16 and a clamping portion 18 in a front portion 20 thereof. The clamping portion 18 consists of an upper clamping jaw 22 separated from a lower clamping jaw 24 by an insert receiving slot 26 . The upper clamping jaw 22 has an upper peripheral surface 27 , having a chip evacuation recess 21 in a front portion thereof, a lower surface 23 and a substantially radially directed through bore 28 . The lower clamping jaw 24 has a lower peripheral surface 29 , having a chip evacuation recess 25 in a front portion thereof, an upper surface 30 and a substantially radially directed threaded bore 31 which is aligned with the through bore 28 in the upper clamping jaw. The upper surface 30 has a base abutment surface 32 constituting a clamping region and a rear abutment surface 34 , constituting an insert location surface, that is slanted with respect to the longitudinal axis A and directed substantially perpendicular to the base abutment surface 32 . Shown in the figure is a channel 35 that separates the rear abutment surface 34 from the base abutment surface 32 . It should be noted that the channel 35 is created during the manufacturing process and is not an essential feature of the lower clamping jaw 24 . At the rear of the insert receiving slot 26 is a flexibilizing bore 36 which is transversely directed to the longitudinal axis A and merges with the upper clamping jaw 22 and the lower clamping jaw 24 creating a resilient connection between the two jaws.
[0049] The lower surface 23 of the upper clamping jaw 22 has a semi cylindrical groove 40 , which, when viewed from the top of the cutting insert holder 12 , is directed preferably perpendicular to the rear abutment surface 34 , and an open sided groove 42 which is parallel to the groove 40 . The upper surface 43 of the groove 42 constitutes a top front abutment surface.
[0050] Attention is now drawn to FIGS. 7 to 11 . The cutting insert 14 has a flat disc like body with an axis of rotational symmetry B, an upper surface 46 , a lower surface 48 and a peripheral side surface 50 connecting between the upper surface 46 and the lower surface 48 . A through bore 51 aligned with the axis B passes through the cutting insert 14 .
[0051] The peripheral side surface 50 has two identical sets of cutting edges. Each set of cutting edges consists of an upper cutting edge 52 and a lower cutting edge 54 . The upper cutting edge 52 meets with the lower cutting edge 54 at apex 56 . The upper cutting edge 52 has a rake surface 58 and a relief surface 60 . The lower cutting edge 54 has a rake surface 62 and a relief surface 64 . In the region between the two apexes 56 , on diametrically opposite sides of the peripheral side surfaces 50 , the relief surface 60 of each set of cutting edges merges with the relief surface 64 of the other set of cutting edges at merging regions 65 (see FIG. 11).
[0052] The lower surface 48 of the cutting insert has a bottom abutment surface 66 and two identical symmetrically disposed rear abutment surfaces 68 directed substantially perpendicular to the bottom abutment surface 66 . On each side of the lower surface 48 of the cutting insert, the rake surface 62 together with rear abutment surface 68 form an elongated recess in a portion of the peripheral side surface.
[0053] The upper surface 46 of the cutting insert has two identical elongated parallelly extending ridges 70 and 72 . The ridges 70 and 72 are directed substantially perpendicular to the rear abutment surfaces 68 when viewing the cutting insert 14 from the top. The ridge 70 is identical to the ridge 72 and therefore only one ridge will be described. The ridge 70 extends between the two relief surfaces 64 and has a flat top surface 74 . The ridge 70 has an indentation 76 substantially in the middle thereof. The ridge 70 also has an inner side surface 78 and outer side surface 80 , both of which are curved.
[0054] The assembly of the cutting tool assembly 10 will now be described, primarily with reference to FIGS. 13 to 16 . The cutting insert 14 is inserted into the insert receiving slot 26 such that the upper surface 46 of the cutting insert 14 is facing towards the lower surface 23 of the upper clamping jaw 22 , the ridge 70 is introduced into and parallel to the groove 40 , and the ridge 72 is introduced into and parallel to the groove 42 . In this position the cutting insert 14 is slid into the insert receiving slot 26 till a rear abutment surface 68 of the cutting insert abuts against the rear abutment surface 34 of the upper surface 30 of the lower clamping jaw 24 . Now, the screw 15 (not shown in FIGS. 13 to 16 ) is inserted into the through bore 28 of the upper clamping jaw 22 , through the through bore 51 of the cutting insert 14 , and threadingly engaged into the threaded bore 31 of the lower clamping jaw 24 .
[0055] The tightening of the screw 15 can conveniently be considered as a two stage process in the clamping of the insert. FIG. 13 shows the relative position between the cutting insert 14 and the clamping portion 18 prior to tightening of the screw 15 . In the first stage of tightening, as shown in FIG. 14, the upper clamping jaw 22 and the lower clamping jaw 24 approach each other. At this stage the ridge 70 abuts the inner surface of the groove 40 . Due to the difference in the cross sectional shape between the ridge 70 and the groove 40 a clearance 82 is formed between the upper region 84 of the groove 40 and the top surface 74 of the ridge 70 . Due to this clearance the ridge 70 abuts the groove 40 along front abutment region 86 and rear abutment region 88 . The front abutment region 86 coincides generally with a line along the inner side surface 78 and the rear abutment region 88 coincides generally with a line along the outer side surface 80 . Because of the indentation 76 in the ridge 70 the front and rear abutment regions are both divided into two portions. In the second and final stage of the tightening of the screw (as shown in FIG. 16) the upper surface 43 of the groove 42 abuts the flat top surface 74 of the ridge 72 .
[0056] As a result, the cutting insert 14 is retained in a firm and precise manner in the insert holder with the ridge 70 wedged into the groove 40 , the ridge 72 clamped by the upper surface 43 of the groove 42 and the rear abutment surface 68 of the insert abutting against the rear abutment surface 34 of the upper surface 30 of the lower clamping jaw 24 .
[0057] Although the present invention has been described to a certain degree of particularity, it should be understood that various alterations and modifications can be made without departing from the spirit or scope of the invention as hereinafter claimed.
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A cutting insert holder has a lower clamping jaw resiliently connected to an upper clamping jaw. The upper clamping jaw is provided with two elongated spaced apart parallel grooves. The cutting insert is retained in the cutting insert holder by means of a screw which passes through a through bore in the upper jaw of the insert holder, through a through bore in the cutting insert and is threadingly engaged into a threaded bore in the lower clamping jaw. The two elongated ridges in the upper surface of the cutting insert cooperate with the two elongated parallel grooves in the lower surface of the upper clamping jaw.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional application Ser. No. 60/580,205, filed Jun. 16, 2004, the disclosure of which is hereby incorporated by reference herein.
TECHNICAL FIELD
[0002] This patent relates generally to molecular modeling and modeling of semiconductor devices. Specifically, the patent relates to the determination of electrostatic potential by using a direct computational approach.
BACKGROUND OF THE INVENTION
[0003] Electrostatic potential in molecular systems is created by the nuclei and the electrons. Chemical reactivity and molecular interactions depend on the electrostatic potential. Electrostatic potentials are of fundamental importance in simulations of charging processes of semiconductor structures and devices. Electrostatic potential is a measurable physical quantity, but it is more commonly obtained in computer simulations. Nuclear contributions to the electrostatic potential can be obtained analytically, whereas calculation of the electronic contribution is more involved as it is created by the static electron distribution rather than by point charges.
[0004] Because electrostatic potentials can be obtained analytically only for some simple systems, determination largely relies on numerical methods. Calculation of electrostatic potentials is straightforward, since electrostatic potentials-are generated as the integral of the reciprocal interparticle distance, |r 1 -r 2 |, times a general charge distribution. Newtonian gravitational potentials may be obtained using similar expressions as used in the calculation of electrostatic potentials.
[0005] Such a direct approach has seldom been used as it is considered to be very complicated and time consuming due to the potential involving a six-dimensional space with singularities at r 1 =r 2 . The preferred method of solving for the electrostatic potentials is to numerically solve the Poisson equation in three dimensions. The Poisson equation is a second-order elliptical partial differential equation describing the electrostatic potential caused by a fixed charge distribution. In three dimensions, the Poisson equation is shown as:
∇ 1 2 φ( x 1 , y 1 , z 1 )=−4πρ( x 1 , y 1 , z 1 )
[0006] Solving the Poisson equation numerically is a complicated task since it involves large linear matrix equations with crucial system specific boundary conditions. Because of its importance, much effort in the scientific community has been dedicated towards developing efficient methods of solving the Poisson equation.
[0007] Other approaches have been useful for obtaining the electrostatic potential; however, these methods often provide qualitative rather than quantitative accuracy. Several numerical methods of determining the electrostatic potential in chemical and biological systems have been developed in computer programs such as, APBS, DelPhi, ITPACT and Manifold Code.
[0008] Equally important applications of Poisson solvers are real space computational methods for electronic structure, the electrostatic potentials caused by the electrons are determined with high accuracy using the Poisson equation. However, this is one of the most time consuming steps in real space computations.
[0009] Electrostatic potential is also of great importance in studies of semiconductor devices. Solutions to the Poisson equation for semiconductor structures and quantum dots provide information about their properties and physical insights into the single electron charging processes.
[0010] What is needed is a technique that accurately determines electrostatic potential for complex molecular and semiconductor systems.
SUMMARY OF THE DISCLOSURE
[0011] A method for solving differential equations for electrostatic potential is presented, in which the electrostatic potential may be estimated in a system without knowing boundary conditions. The method includes separating a multi-dimensional integral into a coupled product of multiple one dimensional (1D) integrals by applying an integral transformation and using numerical tensorial basis functions, and constructing matrices containing one-dimensional auxiliary integrals for each dimension. Further, the method approximates the auxiliary integral of the integral transformation by using numerical quadrature. Matrix multiplications are performed for each dimension and for each integration point in an auxiliary dimension. The differential contributions are numerically integrated to obtain the electrostatic potential for the system.
[0012] A computer system is described that executes a software program in estimating the electrostatic potential for the system. The computer system includes a processor, a memory and a program stored in the memory and executable by the processor. The program incorporates the logic described above in estimating the electrostatic potential.
[0013] The described embodiments solve the Poisson equation to computationally estimate the electrostatic potential.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 depicts a logic diagram consistent with the teachings of the disclosure.
[0015] FIG. 2 is a schematic diagram of a system capable of performing computations in accordance with the logic diagram of FIG. 1 .
DETAILED DESCRIPTION
[0016] The described embodiments recast an equation for calculating electrostatic potential into a more usable format and incorporate this equation into a computer software program. The electrostatic potential is defined as an integrated average of a charge distribution multiplied by a reciprocal distance between a position of a charge causing the potential and a potential coordinate. Mathematically expressed as:
ϕ ( x 1 , y 1 , z 1 ) = ∫ - ∞ ∞ ∫ - ∞ ∞ ∫ - ∞ ∞ 1 r 12 ρ ( x 2 , y 2 , z 2 ) ⅆ x 2 ⅆ y 2 ⅆ z 2 ( 1 )
where ρ(x 2 , y 2 , z 2 ) is a charge density,
r 12 = r 1 - r 2 = ( x 1 - x 2 ) 2 + ( y 1 - y 2 ) 2 + ( z 1 - z 2 ) 2
is a distance, and φ(x 1 , y 1 , z 1 ) is the electrostatic potential. Thus, determination of φ(x 1 , y 1 , z 1 ) using Eq. (1) involves six spatial dimensions e.g. (x 1 , y 1 , z 1 ) and (x 2 , y 2 , z 2 ), and a singular function, because r 12 appears in the denominator. Singularities may be removed; by applying an integral transformation to recast the mathematical expression.
∫ - ∞ ∞ 1 r 12 ρ ( x 2 , y 2 , z 2 ) ⅆ x 2 ⅆ y 2 ⅆ z 2 = 2 π ∫ 0 ∞ ∫ - ∞ ∞ ⅇ - t 2 ( r 1 - r 2 ) 2 ρ ( x 2 , y 2 , z 2 ) ⅆ x 2 ⅆ y 2 ⅆ z 2 ⅆ t ( 2 )
[0017] The integral transformation in Eq. (2) has been used in deriving an efficient recursion relation for the calculation of two electron integrals over Gaussian functions. Next the charge density ρ(x 2 , y 2 , z 2 ) may be expanded in a numerical tensorial basis. The tensorial basis consists of basis functions constructed as an outer product of one dimensional basis functions.
ρ ( x 2 , y 2 , z 2 ) = ∑ αβγ ⅆ αβ γ χ α ( x 2 ) χ β ( y 2 ) χ γ ( z 2 ) ( 3 )
[0018] In the three dimensional case, substitution of the density in Eq. (3) into Eq. (2) yields a separation of a three dimensional integral into a coupled product of three one dimensional integrals. This substitution also derives an expression for calculation of a potential φ(x 1 , y 1 , z 1 ) at selected points in space. Coordinates of the chosen potential points are shown in the exponent of the Gaussian function; the one dimensional integrals involving the Gaussian function times the basis function have to be calculated analytically or numerically for each potential point and basis function yielding a computational scaling that is proportional to N x 2 +N y 2 +N z 2 , where N x , N y , and N z are the number of grid points in each dimension. Integration in the t direction may be performed numerically using Gaussian quadrature. Thus, an expression for the calculation of the potential in points (x 1 , y 1 , z 1 ) may be written as:
ϕ ( x 1 , y 1 , z 1 ) = 2 π ∑ α t w α t ∑ αβγ ⅆ αβγ ∫ - ∞ ∞ ⅇ - t α t 2 ( x 1 - x 2 ) 2 χ α ( x 2 ) ∫ - ∞ ∞ ⅇ - t α t 2 ( y 1 - y 2 ) 2 χ β ( y 2 ) ∫ - ∞ ∞ ⅇ - t α t 2 ( z 1 - z 2 ) 2 χ γ ( z 2 ) ⅆ x 2 ⅆ y 2 ⅆ z 2 ( 4 )
where integration points t α t and corresponding weights w α t have been introduced. The weights w α t are integration weights of the Gauss integration. Other numerical schemes may yield other weight factors. By denoting the integrals of the Gaussian function times the basis function χ γ x (x 2 ) for the calculation of the potential in point x α x by
F γ x α x x , α t = ∫ - ∞ ∞ ⅇ - t α t 2 ( x α x - x 2 ) 2 χ γ x ( x 2 ) ⅆ x 2 ( 5 )
and similar expressions for the y and z terms, the final expression can be written as
v α x α y α z = 2 π ∑ α t w α t ∑ γ z F γ z α z z , α t ∑ γ y F γ y α y y , α t ∑ γ x F γ x α x x , α t ⅆ γ x γ y γ z ( 6 )
where ν α x α y α z denotes the electrostatic potential values for selected grid points. The evaluation of Eq. (6) includes three coupled matrix multiplications, the matrix size of which are N x ×N y , N y ×N z , and N z ×N y , respectively. Auxiliary integrals in F x,α t , F y,α t , and F y,α t , at can be calculated analytically using error function, but for small t values, the analytical expression suffers from numerical instabilities. However, for small t values the auxiliary integrals can be accurately obtained numerically by using, e.g., Gaussian quadrature. The matrix multiplications in Eq. (6) are performed for each grid point in the remaining direction (i.e. z, y, x) and for each t value. This leads to a computational scaling of
( N x 2 N y N z + N x N y 2 N z + N x N y N z 2 ) N t or
3 N x 4 N t = 3 N 4 3 N t when N x = N y = N z
N x N y N z =N are assumed. Thus, the method scales almost linearly with the total number of grid points as N t is independent of grid size used. Two outer loop indices can be used for the distribution of the computational efforts to the processors of one or more parallel computers. Thus, the increase in speed should be substantially linear because the distributed tasks consist of matrix multiplications with no requirement for communication between the processors.
[0019] Referring now to FIG. 1 . The software implementation of Equation 6 is a series of calculation loops, several smaller loops at 24 , 28 , and 32 within one larger loop at 38 . The number of smaller loops is dependent on the number of dimensions in the system. The larger loop at 38 represents computations for each integration point in the t dimension. In this operation, the Einstein summation convention is used. The Einstein summation convention implies that when an index occurs more than once in the same expression, the expression is implicitly summed over all possible values for the index. The auxiliary integrals are constructed at 20 for each dimension and at each grid point in space. For large t α t , values, the F x,α t , the F y,α t and the F z,α t matrices are band dominant, a property that may be used for acceleration of the computational speed. Linear transformation in the x dimension is performed at 24 . The matrix multiplications for the external indices α 1 , and y z may be performed on one or more parallel processors, thus accelerating computational speed.
[0020] An optional reorder function is performed at 22 ; this function reorganizes the data into a more rapidly accessible form. This reorder function is introduced to make the matrix multiplications as fast as possible, any other manner of reordering the terms or no reordering at all would be acceptable. Additional optional reorder functions at 26 , 30 and 34 similarly reorganize the data.
[0021] Linear transformation in the y dimension is performed at 28 . In this operation, the Einstein summation convention is used again. The α t , and α x indices are external indices and the corresponding matrix multiplications may be performed on one or more parallel processors. Linear transformation in the z dimension is performed at 32 . In this operation, the Einstein summation convention is also used. The α t and α x are external indices and the corresponding matrix multiplications may be performed on one or more parallel processors.
[0022] Contributions to the electrostatic potential for each integration point in the t dimension are multiplied by the integration weight factor and added to obtain the total electrostatic potential at 36 .
[0023] FIG. 2 is a schematic diagram of one embodiment of a computer system used to calculate electrostatic potential. The computer 60 is operatively connected to one or more processors 68 , a memory 62 , an output device 66 and an input device 64 . An executable program 70 is stored in the memory 62 and accessible by the computer 60 . The executable program 70 may use the logic described in FIG. 1 . The executable program 70 calculates, in the spatial grid points, the contribution to the electrostatic potential of each t α t value and these contributions are summed to obtain the total electrostatic potential for the system. A notation is used wherein matrix elements with increasing first lower indices lie subsequently in the computer memory 62 , thus allowing the computer 60 to keep the values as long as necessary and possible in the cache memory, yielding an accelerated computational speed. The computer 60 may divide the matrix multiplications for the outer indices α t and γ z at 24 and for the outer indices at and ax at 28 and 32 between the processors 68 , thereby accelerating the computational process.
[0024] In one embodiment, a tensorial product of Lagrange interpolation functions may be used as a basis function. In this numerical representation, expansion coefficients of the functions are amplitudes of the functions in the grid points. Element functions of arbitrary order may be employed; however, in the described embodiment, second, fourth and sixth order Lagrange interpolation functions have been used. Other kinds of local basis functions, such as, for example, wavelets, splines or any other basis set which can be expressed as a tensor product of the one-dimensional (1D) basis functions may be used. One benefit of this embodiment is that in solving more complicated systems, where higher-order element functions result in more accurate potentials, the higher-order element functions may be performed with almost no additional computational costs (i.e., without slowing down the program).
[0025] The described embodiments are directed at solving the Poisson equation in three dimensions. The disclosure could be adapted in other embodiments to solve the Poisson equation in any number of dimensions as well as solving other types of nonlinear Poisson-Boltzmann equations and other related differential equations such as, for example, Schrödinger equations. In the case of non-linear differential equations, the method may be used iteratively to obtain a solution. For example, in the case of the Schrödinger equation, the method begins with an arbitrary initial guess for wavefunction and energy. Integration. may be performed and new energy values used in a subsequent integrations. The process may be repeated until the energy value converges. One skilled in the art will realize the wide range of equations that may be solved by various implementations of the disclosure.
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A computational method to determine electrostatic interaction by performing direct numerical integration. The method recasts the Poisson equation and approximates the integral by using numerical integration schemes. Multi-dimensional integrals are separated into a coupled product of one-dimensional integrals. Linear transformations are performed and the total electrostatic potential is obtained as a sum of potential contributions for each integration point. The method is computationally efficient and well suited for parallel computers.
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This application is a divisional of application Ser. No. 10/460,080 filed Jun. 11, 2003 now U.S. Pat. No. 6,994,489.
CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable to this application.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable to this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to utility access structures positioned within asphalt or concrete roads and more specifically it relates to a utility cover system for preventing water leakage into a utility access structure within a road surface and for eliminating the need for expensive adjustment structures.
2. Description of the Related Art
Utility access structures have been in use for years for various utilizes such as utility valves (e.g. valve covers), sewers (e.g. manholes) and catch basins. The utility access structures typically have a housing structure positioned within the road surface with a cover removably attached thereto. The housing structure and the cover are typically comprised of a hard material such as metal.
One of the problems with conventional utility access structures is that they allow surface water to flow into the access structures thereby damaging the components within the access structure. Another problem is that when an asphalt road is resurfaced, an upper portion of the asphalt may be ground off which can cause damage to the access structure. In addition, it is often times required that workers manually remove the asphalt surrounding the access structure which is labor intensive and time consuming. To solve the resurfacing problem, adjustable structures (e.g. adjustment rings, etc.) have been created but they are extremely expensive and noisy for surrounding residents.
Examples of patented devices which may be related to the present invention include U.S. Pat. No. 5,536,110 to Tompkins et al.; U.S. Pat. No. 6,196,760 to Sinclair; U.S. Pat. No. 5,723,192 to Jonasz; U.S. Pat. No. 4,368,893 to Gagas; U.S. Pat. No. 5,564,855 to Anderson; U.S. Pat. No. 5,876,533 to House et al.; U.S. Pat. No. 6,179,518 to Suatac; U.S. Pat. No. 4,469,467 to Odill et al.; U.S. Pat. No. 5,299,884 to Westhoff et al.; U.S. Pat. No. 3,858,998 to Larsson et al.; U.S. Pat. No. 4,145,151 to Helms; U.S. Pat. No. 4,540,310 to Ditcher et al.; and U.S. Pat. No. 387,181 to Sinclair.
While these devices may be suitable for the particular purpose to which they address, they are not as suitable for preventing water leakage into a utility entrance within a road surface and for eliminating the need for expensive adjustment structures. Conventional utility access structures are prone to water leakage and interfere with road resurfacing.
In these respects, the utility cover system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of preventing water leakage into a utility entrance within a road surface and for eliminating the need for expensive adjustment structures.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of utility access structures now present in the prior art, the present invention provides a new utility cover system construction wherein the same can be utilized for preventing water leakage into a utility entrance within a road surface and for eliminating the need for expensive adjustment structures.
To attain this, the present invention generally comprises an outer frame having an opening defined by an inner tapered edge, and a wedge cover having an outer tapered edge that fits within the opening of the outer frame. The outer frame preferably has an inner segment and an outer segment, wherein the outer segment is thinner than the inner segment.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.
A primary object of the present invention is to provide a utility cover system that will overcome the shortcomings of the prior art devices.
A second object is to provide a utility cover system for preventing water leakage into a utility entrance within a road surface and for eliminating the need for expensive adjustment structures.
Another object is to provide a utility cover system that is rugged, flexible, lightweight, inexpensive and easy to handle.
An additional object is to provide a utility cover system that provides a watertight seal about a utility access structure.
A further object is to provide a utility cover system that absorbs vehicle impact and disperses vehicle weight thereby reducing damage to the utility access structure.
Another object is to provide a utility cover system that can be ground with the asphalt during a road-resurfacing project thereby reducing the amount of time and labor required to resurface a road.
A further object is to provide a utility cover system that may be stacked to various heights to adjust for differing road surface depths.
Another object is to provide a utility cover system that may be utilized with various types, sizes and shapes of utility access structures.
A further object is to provide a utility cover system that still allows for complete and unobstructed access to the utility without hardware installation.
Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is an exploded upper perspective view of the present invention.
FIG. 2 is a cross sectional view taken along line 2 - 2 of FIG. 1 .
FIG. 3 is an exploded upper perspective view of the present with respect to a utility access structure with the existing road surface.
FIG. 4 is an upper perspective view of the present invention positioned about the utility access structure and upon the existing road surface.
FIG. 5 is an upper perspective view of the present invention partially surrounding by a new road surface.
FIG. 6 is a side cutaway view of the present invention positioned about a utility access structure in a sealed manner.
FIG. 7 is a side cutaway view of the present invention with the wedge cover being partially removed with a tool.
DETAILED DESCRIPTION OF THE INVENTION
A. Overview
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 7 illustrate a utility cover system 10 , which comprises an outer frame 30 having an opening defined by an inner tapered edge 32 , and a wedge cover 20 having an outer tapered edge 24 that fits within the opening of the outer frame 30 . The outer frame 30 preferably has an inner segment 34 and an outer segment 36 , wherein the outer segment 36 is thinner than the inner segment 34 .
B. Outer Frame
The outer frame 30 has an opening defined by an inner tapered edge 32 as best illustrated in FIGS. 1 and 3 of the drawings. The outer frame 30 may have various shapes such as but not limited to rectangular, circular and the like. The outer frame 30 preferably has an inner segment 34 and an outer segment 36 as shown in FIGS. 1 and 3 of the drawings.
The outer frame 30 is preferably comprised of a resilient and flexible material such as rubber and the like. However, the outer frame 30 may be comprised of a rigid structure.
The outer segment 36 preferably is thinner than the inner segment 34 forming a stepped structure as best illustrated in FIG. 2 of the drawings. The inner segment 34 and the outer segment 36 preferably have a common lower portion as further shown in FIG. 2 of the drawings. The lower portion of the outer segment 36 is preferably positioned upon the old road surface 14 , wherein the old road surface 14 may have been ground to a lowered level through resurfacing procedures. The lower portion of the outer frame 30 is preferably attached and sealed utilizing an adhesive or other bonding agent. The outer segment 36 of the outer frame 30 is utilized for receiving the new road surface 16 applied over the old road surface 14 as shown in FIGS. 6 and 7 of the drawings.
As shown in FIG. 2 of the drawings, the inner tapered edge 32 tapers inwardly and upwardly. The inner tapered edge 32 may have an angled structure, curved structure or other shaped structure. The wedge cover 20 is formed to preferably snugly fit within the opening within the outer frame 30 .
C. Wedge Cover
The wedge cover 20 has an outer tapered edge 24 that corresponds to the inner tapered edge 32 of the outer frame 30 as shown in FIGS. 1 through 3 of the drawings. The wedge cover 20 may have various shapes such as but not limited to rectangular, circular and the like. However, the wedge cover 20 is preferably formed to a shape and size similar to the opening within the outer frame 30 .
The wedge cover 20 is preferably comprised of a resilient and flexible material such as rubber and the like. The flexibility of the wedge cover 20 allows it to be removed from the outer frame 30 by prying with a tool 15 or other device.
As shown in FIG. 2 of the drawings, the outer tapered edge 24 preferably tapers inwardly and upwardly corresponding to the inner tapered edge 32 . The wedge cover 20 is removably positionable within the opening of the outer frame 30 as best shown in FIGS. 6 and 7 of the drawings.
As shown in FIGS. 1 and 3 of the drawings, the wedge cover 20 has a bottom surface 26 that is positionable over a utility cover 12 . The wedge cover 20 further has an upper surface 22 that is substantially parallel to an upper portion of the outer frame 30 when positioned within the outer frame 30 as shown in FIGS. 4 through 6 of the drawings.
As shown in FIGS. 1 and 2 of the drawings, the opening and the wedge cover 20 preferably have a similar shape. The wedge cover 20 is preferably positionable in a sealable manner within the opening of the outer frame 30 to prevent water and other debris from entering the utility housing 13 thereby protecting the utility such as a valve 18 .
D. Operation
In use, the user first positions the outer frame 30 about a utility cover 12 of the utility access structure. The user preferably secures and seals the outer frame 30 to the old road surface 14 surrounding the utility housing 13 of the utility access structure. After the outer frame 30 is fully secured, the user then positions the wedge cover 20 within the opening of the outer frame 30 defined by the inner tapered edge 32 as shown in FIG. 4 of the drawings. It can be appreciated that the wedge cover 20 may be first positioned adjacent to the utility cover 12 prior to or simultaneously with the application of the outer frame 30 . A layer of new road surface 16 is positioned upon the outer segment 36 and substantially flush with the inner segment 34 as shown in FIG. 5 of the drawings. If required, the present invention may be stacked to achieve various heights. If an individual desires to access the utility access structure, they simply insert a tool 15 between the wedge cover 20 and the outer frame 30 thereafter prying the wedge cover 20 from the outer frame 30 as shown in FIG. 7 of the drawings. The individual may then access the utility by removing the utility cover 12 and perform the desired procedures. When finished, the utility cover 12 is returned to the utility housing 13 and the wedge cover 20 is repositioned in a sealed manner within the opening of the outer frame 30 . If the road is to resurfaced in the future, the outer frame 30 and the wedge cover 20 may remain during the grinding of the road surface and may be ground along with the asphalt.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed to be within the expertise of those skilled in the art, and all equivalent structural variations and relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A utility cover system and method of covering and sealing an access cover for a utility entrance within a road surface. The utility cover system includes an outer frame having an opening defined by an inner edge, and a wedge cover of resilient material having an outer mating edge that fits within the opening of the outer frame. The wedge cover is removably positionable to cover the access opening by passing through the opening defined in the outer frame.
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[0001] This is a U.S. Original Patent Application which claims priority on United Kingdom Patent Application No. 0211612.7 filed May 21, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and system for the prevention of copyright piracy. In particular the invention relates to a method and system for the prevention of in-theatre copying of a film or show. The invention relates to the prevention of copyright piracy in respect of any event, the reproduction of which might be protected by copyright. For example, films, plays and sporting events such as football matches.
BACKGROUND OF THE INVENTION
[0003] Typically, distribution rights of films are arranged between film distributors and cinema companies or individual cinemas in which the film will be shown. Usually, the cinema company or individual cinema will pay the film distributors for the rights to show the film, the cost of which is recouped through admission charges to the cinema.
[0004] In the case of sporting events such as a football match, a sports broadcaster usually pays the football club for the right to record and broadcast the matches played at their stadium.
[0005] In both cases, it is important and desirable to stop unauthorised copying of the recording of the event i.e. football match or film. Typically, criminals under the guise of a normal viewer enter the cinema with a video camera and record the film directly from the cinema screen onto a cassette, cartridge or other recording medium in the video camera. The recorded film is then transferred onto other media e.g. onto videotapes or via the internet, for illegal distribution on the black market.
[0006] In the case, of a football match the criminal sits in the stadium and records the match with a video camera. Again, once the event has been illegally recorded it can be transferred onto alternative media and distributed on the black market.
[0007] This is very undesirable for the official distributors. Firstly, it represents lost revenue. Secondly, there is the risk that the reputation of the official distributor will be harmed if a low quality product is passed off as the product of the official distributor.
[0008] A method and system for overcoming these problems is required.
SUMMARY OF THE INVENTION
[0009] According to the present invention, there is provided a method of prevention of copyright piracy, comprising the step of, at an event, transmitting a signal to interfere with the operation of a recording device e.g. a video camera, thereby interrupting any recording by the recording device at the event.
[0010] Preferably, the signal is an infrared signal comprising a sequence of coded pulses. More preferably, a plurality of signals are transmitted, each signal corresponding to a known sequence of coded pulses of the remote control of one or more recording devices, such as video camera remote controls. The signals are chosen to correspond to the known sequence of coded pulses of the remote controls of a selected number of the most popular video cameras so that it is extremely unlikely that a criminal will be able to continuously record the event.
[0011] In one example, the transmission of the signal or signals is repeated at a predetermined interval, that may be regular, so that if a criminal realises that the camera has stopped recording and manually activates the camera to recommence recording, it will again be turned off. This ensures that the final recording by the camera will be essentially unwatchable, as, if anything at all is recorded, it will be continuously interrupted.
[0012] Preferably, the transmission is timed to go out at a loud point during the event so that the chance of the criminal realising that the camera has been turned off is reduced.
[0013] According to a second aspect of the present invention, there is provided an anti-piracy system having a transmitter adapted to transmit one or more signals at predetermined frequencies and a control unit to operate the transmitter. Preferably, the control unit is adapted to operate the transmitter automatically.
[0014] Preferably, the control unit comprises a programmable memory adapted to receive data relating to one or more signals for transmission by the transmitter.
[0015] In one example, the signals are selected to correspond to a known sequence of coded pulses of the remote control of one or more recording devices, such as video camera remote control.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0016] The invention provides a method and system for interrupting the unauthorised recording of an event. The method and system are both simple and robust.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Examples of the present invention will now be described with reference to the accompanying drawings, in which:
[0018] [0018]FIG. 1 shows a cinema fitted with an anti-piracy system according to the present invention; and,
[0019] [0019]FIG. 2 shows a schematic representation of the transmission system used in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] As mentioned above, FIG. 1 shows a cinema fitted with an anti-piracy system according to the present invention. In this example, the anti-piracy system comprises a transmitter 2 positioned in a concealed location within a cinema auditorium 4 . A viewer 6 is attempting to record the film being shown on the screen 8 with a concealed recording device, in this case a camera 10 . The transmitter 2 is controlled by a control unit to provide a signal comprising a known sequence of coded pulses of the remote control of the recording device. The signal provided by the transmitter 2 is usually an infrared signal, comprising a sequence of coded pulses at certain frequencies corresponding to a signal usually produced by the remote control unit of the viewer's camera 10 .
[0021] The signal is controlled in accordance with the camera manufacturer's specification such that it has the effect of stopping or pausing the recording i.e. it activates the STOP or PAUSE function of the camera. An advantage of pausing the recording is that the pause is often silent. Therefore a user of the camera will be unaware that an interruption of the recording has occurred.
[0022] Alternatively, the signal may be chosen to have any effect on the camera so that the recording of the film is interrupted. For example, a sequence of signals could be provided such that a first signal stops the recording and a second signal rewinds a tape onto which the recording is being made. This will ensure that if the viewer 6 then tries to recommence recording he will record over what ever he has recorded already, thereby making the recording disjointed.
[0023] [0023]FIG. 2 shows a schematic representation of the transmission system used in the present invention. The transmission system comprises a control unit 12 and transmitter 14 connected thereto. The control unit 12 comprises a memory (not shown) that is adapted to store data relating to a number of signals to be transmitted by the transmitter 14 . When the system is activated, the control unit 12 communicates with the transmitter 14 causing it to transmit an infrared signal into the cinema auditorium. As explained above this may be a single signal or it may be a sequence of signals designed to ensure that any recording made in the auditorium will be disjointed.
[0024] When the transmission system is initially configured the data relating to the required frequencies is supplied to the memory in the control unit 12 . In addition any desired sequence of signals may be programmed into the control unit. The data relating to the frequencies may be obtained from various camera manufacturers.
[0025] The control unit 12 optionally comprises a receiver 16 to receive sound from the auditorium to enable an automatic determination of the sound level therein. The control unit 12 is adapted to communicate with the transmitter 14 causing it to transmit an infrared signal into the cinema auditorium when the sound level in the auditorium is high e.g. above a predetermined threshold sound level. This reduces the chance of a user of the camera hearing that its operation has been interrupted. Alternatively, the recording can be interrupted at a specified point during a film when it is known that an average viewer will be particularly engrossed in the film. This also achieves the effect of reducing the chance of a user of the camera realising that its operation has been interrupted.
[0026] It will be understood that a single control unit can store data relating to many different models of camera such that only one transmission system is required for each cinema. Where only a single transmission system is used for a cinema, it is preferable that the transmission system is configured to cycle through signals corresponding to each of the different video cameras it has been programmed to interfere with in sequence.
[0027] Any suitable component may be used for the control unit. For example a programmable microprocessor may be used, programmed to operate as described above. Alternatively, an ASIC or any other suitable electronic component maybe used.
[0028] The description above has been in relation to the use of an infrared transmission to cause interruption in the video recording of an event such as the cinema screening of a film. The invention applies also to the unauthorised recording in any way of such an event. For example, the invention also applies to, amongst others, the unauthorised recording of a music concert or stand-up comedy performance.
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The invention provides a method of prevention of copyright piracy, comprising the step of, at an event, transmitting a signal to interfere with the operation of a recording device such as a video camera, thereby interrupting any recording by the recording device occurring at the event.
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BACKGROUND OF THE INVENTION
[0001] During the early to mid-1980s, car manufacturers, under pressure to increase fuel economy and simultaneously reduce emissions, switched to electronic fuel injection to obtain more precise control of engine fuel under all operating conditions. When the automotive aftermarket saw the trend, it entered the field, first with PROM chips that allowed the buyer to modify the constants programmed into the electronic controller unit at the factory by simply switching chips. This allowed one to increase performance somewhat, generally at the expense of gas mileage, and to make engine modifications for which changes in program parameters were needed. Gradually, conversion kits were developed to allow hobbyists and racers to upgrade carbureted engines to Electronic Fuel Injection (EFI) or to replace OEM Electronic Control Units (ECUs) to obtain much more control over the system than the re-programmed PROM chips allowed. One of the first of these was U.S. Pat. No. 4,494,509 (1985) to Long. Although now plentiful, these kits are quite costly and difficult to install and configure. Numerous drivability problems whose solutions are beyond the capabilities of the users are also often reported after the installation. Furthermore, the price of these systems places them well beyond the reach of most hobbyists and enthusiasts.
[0002] The present invention provides an engine controller that is: more cost effective because of its low parts count due to integrated technology; simpler to install because of its generic design and flexible software, allowing it to be used with all models and makes of engines from motorcycles to trucks, even or odd number of cylinders, and regardless of the experience of the end user. The design is also more reliable because of several software algorithms that will be described.
OBJECTS AND SUMMARY OF THE INVENTION
[0003] A general object of an embodiment of the present invention is to provide a simple, reliable, user configurable system (electronic circuit and software) for electronic fuel injection control.
[0004] An object of an embodiment of the present invention is to provide an aftermarket EFI system that can be manufactured at low cost.
[0005] Another object of an embodiment of the present invention is to provide a generic EFI system that can be used with a large variety of engines of different sizes, numbers of cylinders, types and sizes of fuel injectors, and types of ignition systems.
[0006] A further object of an embodiment of the present invention is to provide an EFI system that can be easily installed by hobbyists and non-professional users with only a limited knowledge of electronics, computers, and the principles of electronic fuel control.
[0007] Another object of an embodiment of the present invention is to provide an EFI system with reduced susceptibility to electronic noise.
[0008] Briefly, and in accordance with at least one of the foregoing objects, an embodiment of the invention provides an integrated microprocessor based electronic circuit and software that uses an external tachometer signal and various sensor inputs to calculate combustion engine fuel requirements, and provides corresponding electronic control signals to open and close the engine mounted fuel injectors. Parameters for the calculation of these signals are user configurable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention may best be described with reference to the accompanying drawings in which:
[0010] FIG. 1 is a block diagram providing an overview of the system.
[0011] FIG. 2 shows specifics of the integrated microprocessor and its regulated power supply.
[0012] FIG. 3 provides circuit diagrams of the conditioning and filtering of the sensor inputs.
[0013] FIG. 4 provides circuit diagrams for the fuel injector drivers, auxiliary outputs, and status LED lights.
[0014] FIG. 5 provides a block diagram of the software logic.
[0015] FIGS. 6A to 6 G provide a software assembler listing for the ECU in the form of s-records that can be downloaded to a suitable micro controller.
DETAILED DESCRIPTION OF THE INVENTION
[0016] While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as described herein.
[0000] 1. Circuit Description
[0017] The overall hardware system is shown in FIG. 1 and is detailed in the following figures. We start the circuit description with the power supply (U 5 in FIG. 2 ). This is an automotive grade linear 5-volt regulator that can, by itself, handle reverse and over-voltages. To this has been added the combination of diodes D 14 and D 16 , which clamp reverse voltage spikes to −12 volts. D 13 only permits positive polarity voltage to pass to D 15 , which clamps this voltage to 22 volts eliminating the over-voltage effects of switched loads. The total combination provides an extremely robust power supply. Also, there are two power supply filter circuits—one consists of capacitor C 18 and inductor L 1 , providing power to the internal Phase Lock Loop (PLL) clock, and L 2 , C 21 , and C 22 , which filter the analog power supply for the analog-to-digital converter.
[0018] The CPU of choice for this application is the Motorola MC68HC908GP32 (U 1 ). This CPU is a member of Motorola's HCO8 family of micro controllers, providing a rich integration of features, and hence allows a low system parts count. The CPU core runs at an internal bus speed of 8 MHz, which is derived from an internal phase-locked loop clocked from a 32.768 KHz crystal (Y 1 ). The GP32 version has 32 Kbytes of on-chip flash ROM memory with direct in-circuit programming, which allows for the storage and runtime re-programming of constants that is extremely desirable in this application. There are 512 bytes of on-chip RAM memory—more than adequate for this application. Other features include two 16-bit, 2-channel timers, serial communication channels, and an 8-channel, 8-bit Analog to Digital Converter (ADC) for measuring sensor inputs.
[0019] The CPU oscillator circuit is comprised of a 32.768 watch crystal (Y 1 ), two capacitors (C 23 and C 24 ), and two resistors (R 21 and R 22 ). The on-chip PLL clock circuit requires the external loop filter network C 19 , C 20 , and R 20 . The microprocessor has an internal power-on reset circuit, so no external circuitry is required.
[0020] Tuning of system configuration parameters while the engine is running is key to a successful injector control unit. This system uses a standard RS-232 communication interface chip (U 6 ) to talk to a host PC, which is running a custom application that allows the download and tuning of the relevant parameters.
[0021] The sensor inputs to the system are shown in FIG. 3 . The driving input for the system is the tachometer or timing signal, which is generally taken from the ignition circuit (ignition coil primary circuit or tachometer drive). This signal is clipped to +5V by Zener diode D 8 , and applied to a 4N25 opto isolator (U 4 ) providing immunity to damage from over-voltage. The phototransistor in the opto isolator is biased by R 11 and fed into the interrupt pin IRQ1 of the micro controller. By timing the interrupts and knowing that each one represents a cylinder firing, the RPM can be calculated by the micro controller. Furthermore, to significantly reduce the probability of a false tach trigger, a software time-adaptive filter is used on the interrupt such that it is only re-enabled for future triggers after some point in the RPM period is reached, for example the V2 way point.
[0022] The other critical input to the system comes from the manifold absolute pressure (MAP) sensor (U 3 ) that monitors intake manifold vacuum. The sensor used here is the Motorola MPX4250 which is an integrated pressure sensor containing the sensing element, coupled to the engine manifold by a flexible tube, and an amplifier and temperature compensation circuitry all in one package, yielding an analog output which is proportional to applied pressure (absolute, not gauge). The output of the MAP sensor is filtered by R 2 and C 4 , clamped by diode D 1 , and is supplied to channel 0 of the ADC in the micro controller. Using this sensor allows the system to handle normally aspirated and turbo engines to 2.5 Bar. Also, the MAP sensor ADC is sampled in the CPU at a fixed time after receipt of the tach signal; doing this eliminates fluctuation of the pressure due to piston motion during the engine cycle, and hence provides a consistent fuel mixture and a smoother running engine.
[0023] This fuel injection system is of the “speed-density” variety, meaning that the amount of air consumed (and required fuel) is deduced from the manifold absolute pressure and the RPM at which the engine is operating. Hence, with just these inputs, the engine can be run; the other inputs that follow provide more optimal control under different load and environmental conditions.
[0024] Engine temperature measurements are sensed by negative-coefficient thermistors mounted in the intake air stream (MAT) and engine coolant liquid (CLT). In order to sense the resistance of the sensors, they are configured as part of a voltage divider circuit—R 4 for the MAT sensor and R 7 for the CLT sensor. One side of each sensor is tied to ground. The resultant divider voltage is filtered by R 5 and C 5 , C 6 for the MAT sensor and R 8 and C 8 , C 7 for the CLT sensor, and protected from over-voltage by D 2 and D 3 .
[0025] Real-time sensing of throttle position is required by the CPU in order to provide more fuel during periods of rapid throttle opening. The standard throttle position sensor (TPS) is a simple 10K potentiometer attached to the engine throttle shaft with a constant voltage (5 volts in this case) across the potentiometer. The wiper terminal of the pot will therefore provide a variable voltage between 0 to 5 volts. This voltage is filtered by C 10 and R 9 and clamped by diode D 4 , and then applied to ADC channel 3 .
[0026] Other input sensors include battery voltage (needed to adjust the injector opening time), derived by the resistor divider consisting of R 3 and R 6 , and the exhaust gas oxygen content sensor ( 02 ). The 02 sensor is a special device that generates a small voltage (approx. 0.6 volts) when the ratio of gas to air is less than 14.7. Once again, the common theme of filtering (R 1 and C 2 ) and limiting (D 11 ) is utilized.
[0027] The boot loader header (H 1 ) allows a user to pull the battery voltage terminal (AD 4 ) on the CPU down to ground. This is sensed in the CPU software and is recognized as the signal to cease normal operation and load new software in the CPU ROM memory using the RS232 port.
[0028] FIG. 4 is the schematic for the various output drivers for fuel injectors and relays. Starting with the fuel injectors, there are two separate but identical fuel injector drivers (only the first of them will be described). A timer output compare/PWM channel in the CPU is fed into one of the two input channels of the transistor driver chip (U 7 ), which provides fast gate drive (via R 12 ) to the Field Effect Transistor (FET) Q 2 . This is important because the injector needs to be opened as rapidly as possible if fuel metering is to be precise. The fuel injectors are pulled low by Q 2 , and over-voltage and inductive kickback from them are handled by the combination of Zener diode D 21 and the Darlington transistor (Q 1 ). The two FET injector drivers may be connected to two banks of as many injectors as the drivers can handle. This must be determined by the injector current requirements, but 4 injectors per bank is easily achievable. The user can specify through the configuration software how often to fire each bank of injectors relative to the tach input, and whether to fire them sequentially, so that each injector fires once every engine cylinder cycle of two crank revolutions, or simultaneously, such that each injector fires every crank revolution. This allows the system to be used with throttle body injectors (one or two central injectors) or multiport (one injector per cylinder).
[0029] To be truly generic it is required that the system handle the two common electrical impedances for fuel injectors: high impedance (roughly 12-16 ohms) and low impedance (1.2 to 2.5 ohms). The high impedance type (also known as saturated) provides its own current limiting, due to its comparably high resistance, and can be driven directly by Q 2 . The low-impedance types, known as peak-and-hold injectors, require a different drive strategy. These injectors like to have higher “peak” current applied, say 4 amps, while they are opening, and a lower “hold” current (like 1 amp or so) to keep them open. To provide this relative current control, Q 2 is driven fully on during the time the injector is opening. When a predetermined time has elapsed which is sufficient to ensure that the injector is open (based on injector impedance and supply voltage), the drive to Q 2 is switched to a pulse-width modulation mode (using the PWM mode of the timer channel), with a frequency of 15 KHz and a duty cycle which keeps the average current through the injector at the desired “hold” value. Both the duration of the “peak” current and the amount of reduction in amplitude during the “hold” portion are configurable by the user in the software.
[0030] Direct control of a fast-idle solenoid is provided by Q 5 (spikes limited by D 9 ), which is opened when the engine is first started and not at a fully warmed temperature. The fast idle solenoid provides an air bypass around the throttle plates to provide additional air in the intake manifold. The operation of the electric fuel pump is also controlled in the micro controller (via a relay) using Q 3 .
[0031] Finally, three LED lights are switched by transistors Q 9 -Q 11 . The first tells the user that the injectors are being driven, the other two tell the user when extra fuel enrichment is being supplied to compensate for cold engine warm up, and for acceleration, as indicated by a large throttle opening rate.
[0000] 2. Software Description
[0032] A summary of the software flow is provided in FIG. 5 , and a complete listing of the embedded code is provided in FIG. 6 in the form of s-records which can be downloaded into Motorola HC08 series micro controllers through a serial port with commercially available software for this purpose installed on a host computer. As can be seen from the flowchart, the main loop of the program performs calculations on a continuing basis, as long as there are no interrupts. The latter, shown in the right column of FIG. 5 , are used for time critical operations and for a 100 microsecond clock.
[0033] The primary control algorithm, performed in the main loop of the embedded program, is the calculation of injector on time or pulse width. For this simple fuel injection system, the equations used for this have been optimized as follows:
air_density=0.3916*MAP/(MAT+459.7)
mass_air=air_density cylinder_volume
mass fuel=mass air/ AFR
Inj — PW =mass_fuel/Inj_Flow_Rate
[0034] The injector flow rate is a constant measured at the factory by flowing the injector at the line pressure specified for the car. The fuel required in the above equation depends on the amount (in mass) of air entering the engine and the desired air/fuel ratio (AFR). In the above, air density is in pounds per cubic foot, MAP in kiloPascals, MAT is the intake manifold air temperature in degrees Fahrenheit, and the 459.7 converts to degrees Kelvin. The volume of the cylinder is in cubic feet.
[0035] To simplify the calculations required by the microprocessor, one can define a quantity at a specific set of input values. In this system, we define the variable Req_fuel which is the amount of injector open time required for a MAP value of 100 Kpa (essentially wide-open throttle), MAT value of 70 degrees F., and assign values for AFR and cylinder volume which relate to the application. Req_fuel is a constant inside of the program. With this definition, the code is simplified by the use of direct units for the calculations, for example, MAP readings in Kpa/100 can be directly multiplied by Req_fuel to yield the change in pulse width time. Also, quantities, like volumetric efficiency (VE), which is the efficiency of the engine in pumping air at a specific RPM and load, can also be directly multiplied to the Req_fuel value. Likewise, acceleration and warm up enrichment values are directly multiplied in normalized percentages, as well as feedback settings for closed loop operation ( 02 ). Lookup tables for percent changes from the defined baseline value for Req_fuel is also used for temperature correction and barometric pressure correction, and are multiplied in a similar manner. This approach is very intuitive for users and yields:
Inj_PW=Req_fuer(MAP/100)*( VE/ 100)*(02/100)*(Warm/100)*(Acce1/100)*(Baro/100)*(Air/100).
[0036] The preceding description covers the basic requirements, but there are several other corrections that need to be made. The first of these is enrichment for a cold start. During the cranking period and for at least a minute or more thereafter, an extremely rich fuel mixture is required for the engine to fire and run properly. How rich depends on the coolant temperature as measured by the coolant sensor. Hence, a user-configurable table is provided in flash memory for fuel enrichment vs temperature, and this is factored into the injector pulse width equation. As the engine warms up, the enrichment tapers off.
[0037] During the cranking phase, more sophisticated strategies employ asynchronous injection, in which the injector is made to pulse several short bursts of fuel rather than a single long shot. This produces better mixing of the fuel and air. This is needed during cranking, because there is very little engine vacuum generated at the slow cranking speeds. Hence, the air moves very slowly through the intake tract and does not mix well with the fuel, thereby producing a weaker and rougher combustion event.
[0038] A second area requiring special enrichment is acceleration. When the throttle is depressed rapidly for acceleration, a very rich mixture is required for a short period to keep the engine, from stumbling. To do this the ECU must first sense that acceleration is occurring. It does this by polling for a TPS and/or MAP sensor rate of change that is above a fixed threshold. When this occurs, the mixture is enriched by an amount, and for a time period, which is a function of the rate of change.
[0039] Another fuel correction commonly used is for barometric pressure. This affects the airflow and air density, and hence the fuel must be corrected to maintain a desired AFR. In the present system the intake MAP reading just before starting the engine is used as the barometric pressure, and a correction table is applied.
[0040] A stoichiometric air/fuel ratio of 14.7 is generally considered optimal for all around driving, economy and emissions, and this is what is strived for in closed loop mode using oxygen sensor feedback. This sensor, as the name implies, sends back to the ECU a voltage proportional to the amount of free oxygen in the exhaust. Too much means a lean mixture requiring more fuel be added; too little, just the opposite. Thus, in closed loop mode a PID loop is used to modify the basic fuel equation so as to maintain a just right fuel mix regardless of the type of gas used or the amount of wear in the engine. This mode is used off idle during cruise conditions when such a stoichiometric mixture is desired.
[0041] The fuel injector is a solenoid tied to battery voltage on one end, and is grounded by the ECU at the other end when it is desired to turn on the injector. Now the specification injector flow rate is for steady state conditions, but the injector in the engine is not run at steady state, it is constantly pulsed on and off, and requires about 1-2 ms to fully open, and 1 ms to fully close. (During opening it is fighting spring pressure, while the spring assists in closing.) This fact requires two more corrections for fuel regulation. One is for the fact that the flow rate is not constant during the open/close ramps, and the other is a compensation for battery voltage, which has an effect on the open time. If the battery is weak, the injector will take longer to open. Hence, battery voltage is measured as shown in FIG. 3 , and the injector open time is modified either linearly or from a table according to the deviation of battery voltage from 12 volts.
[0042] A practical feature of the software not directly related to engine control is the provision for a bootloader program. This feature allows corrections and upgrades to the software to be easily downloaded by the users when they are developed.
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An electronic engine fuel controller that is simple, low cost, easily installed, and configurable for any internal combustion engine. The system is intended for upgrading older carbureted vehicles or vehicles that have been modified beyond the limits of the OEM controller. It takes advantage of modern micro controller technology with integrated memory, digital input/output, sensor and timer channels to produce a low parts count, as well as reliable operation in a large variety of vehicles, even when installed by people with little experience or knowledge in this area. Operation is by sensing a tachometer signal from the existing distributor, ignition coil, toothed wheel or similar device that produces one electronic pulse for each cylinder cycle. When a pulse is received, software in the micro measures engine operating parameters, calculates fuel parameters, and fires one or more injectors depending on how the system is configured. Configuration software operating on an external computer or laptop and communicating with the micro allows the user to modify any of the controller parameters or tables used for the fuel calculations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to sport hunters' equipment. More specifically, it relates to backpacks or pack boards on which hunters can conveniently carry harvested game back to their camp or vehicle.
2. Description of Prior Art
It is well known to all persons such as hunters, hikers and others who are experienced in backpacking of heavy loads, that a rigid backpack frame is conventionally used with a canvas stretched across it for resting comfortably against a wearer's back. Such backpack frame carries the weight high up so a person can walk erect without need to lean forward, and thus does not tire even after long distances because the weight is on the shoulders and not on the back. However, when not in use carrying a load, its size hinders a person's free walking movement.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention, to provide a portable pack frame that can be readily taken apart when not needed to transport a load, so that it may be stowed in a small storage bag commonly termed by hunters as a "fanny pack" for easy carrying.
Other objects are to provide a portable take apart pack frame which is simple in design, inexpensive to manufacture, rugged in construction, quick and easy to assemble or disassemble and efficient in operative use.
These and other objects will be readily evident upon a study of the following Specification and the accompanying Drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the frame of a portable take apart pack, shown exploded;
FIG. 2 is a perspective view of a typical webbing used with the pack;
FIG. 3 is a typical cord used to lace the webbing closed;
FIG. 4 is a perspective view of a typical strap used with the pack;
FIG. 5 is a rear elevational view of the pack, assembled with a storage bag, shown attached to the frame;
FIG. 6 is a perspective view of the frame used as a seat, and
FIG. 7 is a perspective view of another embodiment of the invention, in which extra tubing and webbing converts to a wilderness stretcher for large game or injured hiker.
DETAILED DESCRIPTION
Referring now to the drawing in greater detail, and more particularly to FIGS. 1 to 6 thereof, at this time, the reference numeral 10 represents a portable take apart pack frame, incorporating the present invention, and which includes a lower sub-assembly frame unit 11, an upper sub-assembly frame unit 12 and a pair of extension bars 13 therebetween. The parts are made preferably of strong, light weight, tubular metal. Each unit 11 and 12 comprises an arcuate end tube 14 and a pair of side tubes 15 welded together at their ends into a general "U"-shape, and an arcuate cross-brace 16 between the free ends of the side tubes. The free end of the side tubes have openings 17 for receiving ends 18 of the bars 13 when assembling the pack frame 10. The arcuate members 14 and 16 bow outwardly toward a direction which forms a rear side of the pack frame. A detent 19 on the side tube snap fits in an opening 20 on the end tube for locking the pack frame in assembled position.
A rearwardly projecting, short stub tube 21 welded on each side tube serves to secure a canvas web 22 around the frame by being received in an opening 23 provided for it on the web. The webs serve to rest against a person's back comfortably. Ends 23a of the webs are attached together by lacings 25 through lace holes 24 on the web.
A pair of shoulder straps 26 are attached to the pack frame by means of a hole 27 on an upper end of the strap being secured by clevis pins 32 and holding wires 33 on the upper tube 14, and a lower end of the strap being fitted through a ring 29 pivotally attached to the lower unit. The strap includes a buckle 30 so to be adjustable in length.
When the pack frame is in use carrying a load, then a storage or "fanny" bag 31 is attached to the lower unit by means of clevis pins 32 and a holding wire 33. A strip of material on the bag has grommetted holes to receive the pins for securement thereto. The bag serves to support a lower end of a load carried on the pack frame.
As shown in FIG. 6, the pack frame may be assembled to form a chair 35 by fitting tubes 13 into stub tubes 21 of the upper and lower units. One unit rests on a ground and a person sits on the web of the upper unit.
As shown in FIG. 7, a modified design of pack frame 10a is generally the same as pack frame 10 except that instead of the above described rods 13, the device includes a plurality of interconnectable rods 13a on each side and a plurality of webs 22, so as to selectively also form a litter or stretcher for carrying a wounded comrade hunter or big game out of a wilderness.
While various other changes may be made in the detail construction, it is understood that such changes will be within the spirit and scope of the present invention as is defined by the appended claims.
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A pack frame made of metal tubing that readily interfits together for easy assembly or disassembly, shoulder straps for support from a person's shoulders and a storage bag attachable to a lower end of the frame.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/221,931, filed Apr. 1, 1994, now U.S. Pat. No. 5,580,523 the entirety of which in incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a method and apparatus for nanoscale synthesis of chemical compounds in continuous flow systems with controlled and regulated reaction conditions. More particularly, this invention relates to a modular multi-component nanoscale system with interchangeable nanoreactors, where the nanoreactors are used in tandem, series, or individually for nanoscale synthesis and is adaptable to prepare up to milligram quantities of desired compounds by adding additional reactor units.
BACKGROUND OF THE INVENTION
Organic and inorganic reactions are usually conducted in reaction vessels that typically hold between 0.5 and 1000 mL of reactants in a research laboratory to commercial reactors holding more than 1000 L. Complex inorganic and organic compounds, e.g., drugs, monomers, organometallic compounds, semi-conductors, polymers, peptides, oligonucleotides, polynucleotides, carbohydrates, amino acids, and nucleic acids belong to a class of materials having significant diagnostic, medicinal and commercial importance. However, the systems necessary to carry out and prepare or synthesize these complex materials are inefficient, wasteful and often times require reagent quantities far in excess of what is available. This is especially the case in those instances where milliliter to liter or larger quantities are involved.
The production of these complex materials requires a versatile system that can handle different reaction and separatory schemes. Most synthesizers provide only for a single type of reactor, e.g., electrochemical, catalytic, solid phase support, enzyratic, photochemical, or hollow chamber. These systems are exemplified by the following:
U.S. Pat. No. 4, 517,338 (Urdea) teaches a system for sequencing amino acids with similar reaction zones having an internal diameter (I.D.) of a 0.1 to 1.0 cm;
U.S. Pat. No. 4,960,566 (Mochida) describes an automatic analyzer and process for serial processing of reaction tubes of a common design;
U.S. Pat. No. 4,362,699 (Verlander et al.) teaches high pressure peptide synthesizers and uses a plurality of reservoirs that communicate via a switching valve to a reactor 90 ;
U.S. Pat. No. 4,458,066 (Caruthers et al.) teaches an amino acid synthesizer with reactor column 10 including a solid silica gel approximately 1 ml. volume in size; and
U.S. Pat. No. 4,728,502 (Hamill) relates to a stacked disk amino acid sequencer.
SUMMARY OF THE INVENTION
The present invention provides an Integrated Chemical Synthesis (ICS) system that is modular in design and is capable of nanoliter (nanoscale) size or microscale size processing via continuous flow or batch operation. The modular nature of the system allows for the use of one or more of the same type of reactors, or a variety of different types of reactors, preferably having nanoscale capacity, but capable of using microscale reactors. The nanoscale reactors of the present invention are capable of being used individually, together, and interchangeably with one another and can be of the thermal electrochemical catalytic, enzymatic, photochemical, or hollow chamber type. The modular nature of the system, component parts, e.g., the reactors, flow channels, sensors, detectors, temperature control units, allows easy addition, replacement and/or interchangeability of the component parts.
Other generic components that are included within this invention are flow components (ie., pumps, valves, manifolds, etc.), mixers, separation chambers, heat transfer elements, resistance, ultrasonic or electromagnetic radiation (U.V., I.R., or visible) sources, heaters and/or analyzers. The components are assembled on a support system, e.g., a chip or board, to form a complete nanoscale system and then replicated many times to produce the synthesizer of the desired scale.
The advantage of a nanoscale synthesizer is better yields of products with less waste and disposal problems because of better control of reaction variables. For example, a cylindrical (capillary) reactor with an internal diameter of 100 mm, 1 cm long, with a cell volume of about 0.08 mL. At a linear flow velocity of 0.1 cm/s, the transit time through the cell would be 10 s, and the volume flow would 8×10−3 mL/s. If conversion of a 1 M solution reactant was complete in this time, then the output of the cell would be 8 nmol product/s. For a product with a molecular weight of 100 g/mol, this would be equivalent to about 3 mg/h or 25 g/year of product. Thus, a bench-sized reactor consisting of 1000 nanoscale synthesis units would produce 69 g/day, while a larger reactor with 176,000 units would be needed to produce 11 kg/year. Considerable yields would require, however, the use of a large number of parallel systems, and to justify their use, the unit cost of each must be very small and their assembly fast and easy.
As a result of the present nanoscale synthesis modular system, the problems of inefficiency, lack of versatility, down-time, reagent/reactant waste and excessive cost have been overcome.
Accordingly, the present invention provides a nanoscale system for synthesizing chemical compounds that is easily upgraded to produce larger quantities of compounds if desired. The system of the present invention can also synthesize compounds under a variety of process conditions, e.g., uniform temperature in a continuous flow reactor under high pressure, non-uniform temperatures and high pressure.
One aspect of the present invention is the use of nanoscale size reactors for combinatorial synthesis, since nanoreactor and nanosystem design allows for the production of small quantities of pure materials for testing.
In accordance with another aspect of the present invention, a modular multicomponent system is provided. The system, e.g. a kit, provides a reaction system capable of handling a variety of reactions by using a reactor unit having a reaction chamber with an I.D. of less than about 0.01 mm up to about 1 mm, and more preferably 0.1 mm-100 mm, most preferably 0.1 mm to 10 mm. Specifically, a modular “chip” type reactor unit is formed by applying a photo-resist layer onto an upper surface of a SiO 2 or Si substrate and forming a reactor design thereon. The reactor design is developed and etched with acid to form a reactor chamber having an internal diameter of less than 100 mm. The chamber is covered and the unit mounted on an assembly board containing fluid conveying channels, with fastening means, to provide for flow to and from the reactor chamber.
In accordance with another aspect of the present invention, a modular multicomponent system containing a plurality of interchangeable reaction vessels, alike or different, in parallel or series, and capable of handling reaction volumes of at least 0.1 nL or from about 0.01 nL up to about 10 mL, and more preferably 1 nL--1 mL is provided.
In yet another aspect of the present invention, a system capable of regulating extreme conditions (e.g., supercritical temperatures and pressures) is provided and therefore avoids potential explosions and, provides a reliable method for heat dissipation.
These and other features, aspects and objects will become more apparent in view of the following detailed description, examples and annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a - 1 d show a fabricated chip type reactor unit for the ICS modular system.
FIG. 2 illustrates an exploded view of a chip type reactor unit and the fluid delivery flow channels of an assembly board according to the present invention.
FIG. 3 is an exploded view of one embodiment of the ICS system
FIG. 4 shows an exemplary ICS system with fluid control and computer interfacing according to the subject invention.
FIG. 5 is a flow chart for preparing t-BuCl using the subject invention.
FIG. 6 shows a flow chart for photochemical conversion of dibenzylketone using the ICS system of the subject invention.
FIG. 7 is a flow chart illustrating electrochemical reduction of benzoquinone according to the present invention.
FIG. 8 is a flow chart for multiphase membrane reactor conversion of benzylpenicillin (BP) to 6 amino penicillanic acid (6-APA) using the ICS system.
FIG. 9 is a flow chart for converting n-C 7 H 16 to toluene using the subject invention.
FIGS. 10 a - 10 d show the shape of a variety of nanoscale reactors that can be used in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is broadly directed towards a total modular system that can use a plurality of replaceable and interchangeable nanoscale reactors. Reducing the size of the reactor, i.e., reaction vessel to enable synthesis on a nanoscale has many benefits. Increased surface area to volume, more efficient heat transfer and simplified thermal control of reaction temperature is vastly simplified. Heat transfer depends on the ratio of surface area, A, to volume, V. This is a significant advantage, for example, in comparing small scale capillary-zone electrophoresis (CZE) to large scale gel electrophoresis:
compare (in a 100 μm cylindrical reactor): A/V ⊂ 2 /r ≅400 cm −1
with (in a 1-L spherical flask): A/V ⊂ 3 /r ≅0.5 cm −1
For the same reason, external beating of the nanoreactor and heat dissipation is faster and the maintenance of uniform temperatures throughout the reaction mixture readily accomplished.
It is easier to work at high pressures with small reactors. Super-critical fluids, for example, particularly those involving high temperatures and pressures, are difficult to study in large volumes, often requiring elaborate safety measures and heavy-duty equipment. The smaller scale reactors facilitate the study of near critical and supercritical water solutions at temperatures up to 390° C. and pressures of 240 bar in a 0.238-cm-I.D. (inner diameter) alumina tube. Consequently, reactions may be conducted under conditions of temperature and pressure that are not commercially feasible for large scale synthesis.
The modular nature of the nanoscale synthesizer also imparts to this system certain advantages over more conventional chemical synthetic methods. Easy scale up of reactions based on the nanoscale synthesis approach is attained by simply adding additional modules of exactly the same type to increase output. For industrial synthesis, this would eliminate proceeding from a bench-scale reaction through a very different pilot-plant configuration to a full-size reactor. Inherent redundancy of multiple parallel nanoscale synthesis reactors implies fewer operational problems, since failed reactors can be replaced without shutting down the entire system. This modular system is inherently much safer as well. The rupture of a single nanoscale synthesizer, even at high temperature and pressure, would cause minimal damage, since the total volume and amounts released would be tiny.
The nanoscale synthesis system of the present invention can include a plurality of individual, detachable reactor units. A variety of different reactors are provided to conduct the basic reactions to develop nanoscale synthetic technology. With a plurality of units, one of the reaction units may be structurally different and capable of permitting a different chemical process. Preferably there may be thermal, photochemical, acid/base, redox electrochemical, thermal or pressure units. The thermal and photochemical reactors require that a heat or light source be focused upon the reactor. An acid/base reactor requires introduction of a suitable acid or base catalyst on a polymer support. The catalyst could also be coated on the internal wall surface of the reactor unit. Reagents used in nanoscale HPLC, which is available, can be adapted for the nanoscale reactors of the present invention. The reactors and other nanoscale synthesis components will be fabricated using lithography techniques, e.g., on glass slides or Si substrates, as described below.
Generally, the nanoscale synthesis system includes (1) fluid flow handling and control components; (2) mixers; (3) pumps; (4) reactor “chip type” units; (5) separatory devices; (6) process variable and/or component detectors and controllers; and (7) a computer interface for communicating with a master control center.
Because the flow systems connecting the reactors and other components of the nanoscale manufacturing plant will be fabricated on chips, identification of the products that emerge from specific outlets is straight-forward; the high synthetic and operational overhead associated with “tagging” each compound in a combinatorial library is thus avoided. Combinatorial synthesis involves the development of a synthetic strategy to allow the preparation of a large number of compounds with different structures by assembling several different chemical building blocks into many combinations. The collection of compounds so generated is called a combinatorial library. Such libraries have been of interest in the development of new drugs, catalytic antibodies, and materials. Combinatorial chemistry has been broadly defined as the generation of numerous organic compounds through rapid simultaneous, parallel, or automated synthesis. Analytical control over the chemistry is a significant advantage in developing smaller, more focused libraries. Ultimately, the control over the chemistry will result in the more rapid discovery and development of drugs by researchers in academia and/or in business settings. And finally, since the reactions may be conducted in solution, the waste associated with normal solid phase synthesis, in which large excesses of reagents are used to ensure complete reaction, is avoided.
The nanoscale synthesis system may also include a support structure for detachably retaining the various components of the system. The support structure can be of the “assembly board type” that will contain prearranged flow channels and connector ports. The desired components of the system can be fastened into these connectors by pins. The desired components will have the necessary fittings that allow them to be sealed with the pre-arranged or selectively located flow channels or connectors. The flow system can also include detachable mixing devices, e.g., static or ultrasonic, some of which can be “chip like” in design. The reaction units, whether “chip like” or not, can be of the thermal, electrochemical, photochemical, pressure type and be any shape, e.g., rectangular or cylindrical.
The separatory components can provide for membrane separation, concurrent or countercurrent flow extraction, chromatographic separation, electrophoretic separation, or distillation. The detectors can include electrochemical, spectroscopic or fluorescence based detectors to monitor the reactants, intermediates, or final products.
In accordance with the preferred embodiment of the present invention, an apparatus for achieving the systems described above is illustrated in FIGS. 1-10.
The basic concept of the subject invention is to produce a modular system, with components (reactors, separation chambers, analyzers, etc.) that are inexpensive and easily assembled. The subject invention can be assembled on a flow channel assembly board in the same way integrated circuitry chips and other electrical components are assembled on a circuit board. In the ICS system various reactors, analyzer(s), e.g., “chip units,” are put together on an “assembly board”. Two approaches to assembling such systems would be (a) custom design chips and assembly boards or, (b) the current capillary high pressure liquid chromatography (HPLC)-capillary zone electrophoresis (CZE) approach with microbore tubing (silica, stainless steel) and various connectors, injectors, pumps, etc. In case (a) the chips could be made from silica (SiO 2 ) (glass), silicon (Si) (as integrated circuit chips), polymers (plastic), and/or metal (stainless steel, titanium).
An example of fabricating a chip unit 100 according to the invention is shown in FIGS 1 a - 1 d . With reference to FIGS. 1 a - 1 d , a substrate of SiO 2 or Si is designed to include a rectangular reaction chamber 4 , although other configurations, discussed below, are contemplated. The chamber 4 is formed by photolithographic processes such as those currently used for integrated circuits and circuit boards. A photoresist layer 2 is deposited on the upper surface 16 of the SiO 2 or Si block substrate 1 and, the desired pattern 3 is formed in layer 2 by exposure to the proper image and development techniques. The rectangular reactor chamber 4 is formed by etching the preformed pattern into the substrate, e.g., with HF for SiO 2 to the extent necessary to form a chamber having the desired volume. For complex structures, multiple photolithographic processes may be necessary. Flow channels for the reactor are similarly fabricated using photolithography from the other side of the substrate. A second photo-resist layer 7 is placed on lower surface 6 , exposed to form port openings 8 and 9 . Thereafter, channels 10 and 11 are formed to provide flow communication to reactor chamber 4 . Finally, a cover is attached to close the upper surface 5 to form a top of the reactor 4 and produce the finished chip. Photoresist layers 2 and 7 also include a plurality of patterns 13 - 16 and 17 - 20 formed thereon so that through channels for fastening pins can be formed. The reactor could also be fabricated at one time, alternatively, with plastic materials, by injection molding or casting techniques. Micromachining (e.g, using the scanning tunneling microscope or scanning electrochemical microscope) of metals and semiconductor substrates could also be used to make the modular units of the subject invention.
The shape of the reactor may be other than rectangular or cylindrical For example, FIG. 10 a shows a circular chamber having planar upper and lower walls. FIG. 10 b shows an essentially rectangular chamber where upstream and downstream ends are hemispherical in shape or as seen in FIG. 10 c triangular. Triangular or curved inlet and/or outlet walls reduce any possible dead volume in the reactor. The reactor can also be serpentine in design to increase residence time, FIG. 10 d.
The following chart depicts volume parameters for differing reactors of the present invention. More particularly, the chart depicts volume characteristics associated with two reactor configurations: (a) a cylindrical-shaped reactor; and (b) an elongated square-shaped reactor.
For a cylindrical reactor, the volume (V) is related to the diameter (d) and the length (L) by the following formula:
V =(π r 2 )( L )=(π( d /2) 2 )( L )=π d 2 L /4.
The first three columns (from left to right) depict the diameter, length, and corresponding volume for a cylindrical reactor.
For an elongated square reactor, the volume is related to the diameter (d) and the length (L) by the following formula:
V=d
2 L.
The last three columns (from left to right) depict the diameter, length, and corresponding volume for a elongated square reactor.
Note the following units in interpreting the following table:
Sym-
bol
Meaning
X = distance of 1 m
Y = volume of 1 m 3 (in liters)
m
meter
1 m
1 m 3
1 × 10 6 mL
cm
decimeter
1 × 10 1 dm
1 × 10 3 (dm) 3
1 × 10 6 mL
cm
centimeter
1 × 10 2 cm
1 × 10 6 (cm) 3
1 × 10 6 mL
mm
millimeter
1 × 10 3 mm
1 × 10 9 (mm) 3
1 × 10 6 mL
μm
micrometer
1 × 10 6 μm
1 × 10 18 (μm) 3
1 × 10 6 mL
nm
nanometer
1 × 10 9 nm
1 × 10 27 (nm) 3
1 × 10 6 mL
pm
picometer
1 × 10 12 pm
1 × 10 36 (pm) 3
1 × 10 6 mL
fm
femtometer
1 × 10 15 fm
1 × 10 45 (fm) 3
1 × 10 6 mL
am
attometer
1 × 10 18 am
1 × 10 54 (am) 3
1 × 10 6 mL
The relationship between cubic centimeters and liters follows: cm 3 ≅1 mL.
Cylindrical Reactor
Elongated Square Reactor
d (μm)
L (μm)
V (μL)
d (μm)
L (μm)
V (μL)
1
10
7.85 × 10 −9
1
10
1.00 × 10 −8
1
100
7.85 × 10 −8
1
100
1.00 × 10 −7
1
1000
7.85 × 10 −7
1
1000
1.00 × 10 −6
1
10000
7.85 × 10 −6
1
10000
1.00 × 10 −5
10
10
7.85 × 10 −7
10
10
1.00 × 10 −6
10
100
7.85 × 10 −6
10
100
1.00 × 10 −5
10
1000
7.85 × 10 −5
10
1000
1.00 × 10 −4
10
10000
7.85 × 10 −4
10
10000
1.00 × 10 −3
100
10
7.85 × 10 −5
100
10
1.00 × 10 −4
100
100
7.85 × 10 −4
100
100
1.00 × 10 −3
100
1000
7.85 × 10 −3
100
1000
1.00 × 10 −2
100
10000
7.85 × 10 −2
100
10000
1.00 × 10 −1
1000
10
7.85 × 10 −3
1000
10
1.00 × 10 −2
1000
100
7.85 × 10 −2
1000
100
1.00 × 10 −1
1000
1000
7.85 × 10 −1
1000
1000
1.00
1000
10000
7.85
1000
10000
10.00
The different kinds of chip units produced according to the subject invention could then be connected to the assembly board containing the desired flow connections (FIG. 2) and also (not shown) electrical connections to electrodes, heaters, etc. FIG. 2 uses o-rings 40 and 41 TEFLON® (tetrafluorethylene (TFE) fluorocrbon polymers), VITRON® (fluorocarbon elastomers based on the copolymer of vinylidene fluoride and hexafluoropropylene) to connect the chip channels 10 and 11 to the corresponding channels 50 and 51 on asssembly board 20 and pins 30 - 37 (or clips) to hold the chip to board 20 .
FIG. 3 shows an assembly of several different chips on a single board with interconnections. In FIG. 3 units 100 , 60 , and 70 are respectively a reactor, a separator and an analyzer. The housings for separator 60 and analyzer 70 are formed in a manner similar to that of reactor unit 100 described above, but include the requisite, structures and components to perform the designated process, e.g., separation, analysis. Pins 30 - 33 connect the units 100 , 60 and 70 to assembly board 80 containing channels 81 - 84 therein. Channels 81 and 82 respectively communicate with channels 10 and 11 in reactor unit 100 . Similarly, channels 82 and 83 communicate with the corresponding channels in unit 60 and channels 83 and 84 communicate with the channels in unit 70 .
Alternatively capillary tubing for reactors, detectors, etc., following current HPLC-CZE practice, sized in accordance with the subject disclosure may be assembled on a support board in a similar manner (not shown).
For capillary tubing, connectors, pumps, etc., using the capillary HPLC approach, can be obtained from manufacturers, such as, Valco, Swagelok, and Waters speialized materials usefull in the subject invention reactors and separators can be made from NAFION® (a perfluoroionomer resin)(ion-exchange) hollow fibers and are manufactured by DuPont.
If a glass substrate is used for the “chip” units, the walls are already SiO 2 . If a Si substrate is used, SiO 2 can be formed by oxidation in air under controlled temperature conditions. For metal substrates, e.g, Ti, a protective and insulating film (TiO 2 ) can also be formed by air or anodic oxidation. It is also possible to coat the walls of the tube with catalyst film, organic films for separations, etc.
FIG. 4 includes an assembly board schematically showing the “chip” type processing units of the subject invention. The assembly board includes a reactor R formed in a manner similar to unit 100 above, but includes a heat transfer system. The reactor R communicates with a chip type mixer Mx at the upstream end and a chip type detector D 1 , e.g., unit 100 , at the downstream end. The detector D 1 communicates with a chip type separator, e.g., unit 60 , which in turn is in fluid communication with a second chip type detector unit D 2 , e.g., unit 70 .
The system of FIG. 4 operates as follows: reagents A and B via pressure actuated pumps PA and PB, and valves VA and VB sequentially or simultaneously flow to the mixer MX. If isolation of a reagent is necessary, after reagent A is fed to mixer MX and discharged to the reactor R 1 , a wash fluid W is conveyed via pump PW and valve VW to the mixer MX and discharged. Signals from detectors D 1 , D 2 , thermocouple TC, and flowmeter FM are transmitted to the computer through interface 90 to control the flow of reagents A and B and temperature, or any additional reagents according to the process to be performed by the subject invention.
Having now generally described this invention, the following examples are included for purposes of illustration and are not intended as any form of limitation.
EXAMPLES 1-2
Diels-Alder Reactions
Organic synthesis via the Diels-Alder reaction involves a process in which two new carbon-carbon bonds and a new ring are formed by the reaction of a diene with a dienophile, where the C 1 and C 4 of the conjugated diene attach to the doubly-bonded carbon atoms of the unsaturated carbonyl compound (dienophile). Two variations are described below. In reaction [1], the reactants and the product are liquids while in reaction [2], one reactant and the product are solids.
In each case the reaction occurs readily at room temperature, but they may be gently warmed to reduce the time required. These reactions are known to be very efficient when conducted on a typical laboratory scale.
In reactions [1] and [2] above, compound (1) can be a C 4 -C 6 diene such as 1,3 butadiene, 1,4 pentadiene, 1,3 hexadiene, 2,4 hexadiene, 1,5 hexadiene, 1,3 pentadiene, 2 methyl, 1,3-butadiene and 2,3-dimethyl-1,3-butadiene. Generally most dienophile compounds are of the form C═C—Z 1 or Z 1 —C═C—Z 2 where Z 1 and Z 2 are CHO, COR, COOH, COOR, COCl, COAr, CH 2 OH, CH 2 Cl 2 , CH 2 NH 2 , CH 2 CP, CH 2 COOH, or halogen and R is a C 1 -C 6 straight or branched carbon chain. Examples of dienophiles include but are not limited to acrolein, methyvinylketone, crotonaldehyde, dibenzlacetone, acrylonitrile, p-benzoquinone, napthaquinones.
EXAMPLES 3—4
1,4 Benzodiazelines Reactions
1,4-Benzodiazepines constitute one of the most important classes of bioavailable therapeutic agents with widespread biological activities. An exemplary starting material for these agents include the following compound where R′ and R″ can be hydrogen or lower alkyl (C 1 —C 5 ) and R′″ can be hydrogen, halogen, trifluoromethyl, amino, nitro, etc.:
As seen below, diazepam (8), which is a well known tranquilizer, can be prepared according to equations 3 and 4 below, where an amide bond formation between 5 and 6 is induced following a standard amino acid coupling technique, and the intermediate amide 7 is cyclized by thermal, acid-catalyzed cyclocondensation to give 8 (eq 3).
While it may be possible to conduct this series of steps in a single reactor, it can also be conducted in two reactors, the first reactor is designed for purely thermal reactions and, the second is designed to contain a suitable acid catalyst on a solid support. Another approach to forming (8) entails an initial condensation of a glycine ester (9) with the benophenone (5) to give the imine (10), which is then cyclized to give (8) (eq. 4).
The more efficient of these two procedures will then be used to prepare a combinatorial library of benzodiazepine derivatives of the general structure 11 (depicted below) where X is hydrogen, lower alkyl (C 1 C 5 ), lower alkenyl or lower alkanoyl, and R′, R″, R′″ are as defined above.
A diverse array of benzophenone and amino acid derivatives are commercially available, and these will be used according to the optimal sequence defined by the previous experiments. It is important to recognize that the combinatorial synthesis of benzodiazepine analogues by the proposed technology occurs in solution and thus has a number of important advantages over conventional solid phase synthetic techniques. For example, stoichiometric quantities of reactants and reagents may be used in these nanoreactors, whereas large excesses of one reactant or reagent are typically required in solid phase synthesis to ensure complete reaction. Each reaction is conducted in a separate reactor, and thus the conditions may be optimized for each pair of reactants, thereby increasing the overall efficiency with which the library may be generated. It should be possible to use infrared or ultraviolet detectors to monitor the progress of different reactions.
In order to apply nanotechnology to the parallel synthesis of a library of compounds, it is simply necessary to route parallel streams of reactants into different reactors. After one reaction is completed, the products from each reaction may be transferred to another reactor for reaction with the next reactant. Lithographic techniques described above are used to design the “plumbing”, and since the precise routing can be programmed, the identification of each compound that emerges from the various reactors is known. Thus, the laborious “tagging” of compounds in the library, which is common to many solid phase protocols, is unnecessary.
EXAMPLE 5
Electrochemically Catalyzed Hydrogenation Reaction
The reduction of an isolated carbonarbon bond by hydrogenation constitutes a useful transformation in organic synthesis. In order to develop an electrochemical redox reactor capable of effecting this conversion, the reduction of the Diels-Alder adduct 3 according to equation 6 is considered.
The reactor will consist of an electrochemical cell with a platinum black cathode useful for electrocatalytic hydrogenations in protic solvents. Such protic solvents include water and alcohols. This reactor is linked with the thermal reactor used to prepare 3 to conduct the entire sequence in a single manufacturing operation.
EXAMPLE 6
Thermal Conversion Reaction
With reference to FIG. 5, solutions of concentrated hydrochloric acid 201 and t-butanol 202 are metered through pumps 203 , 206 and valves 204 , 207 to a mixer 205 to the reaction chamber 208 . Temperature in the reaction chamber 208 is controlled via a heating/cooling system 215 on the assembly board, e.g., 80 , to maintain the reaction temperature (measured by a thermocouple) at about 30-30° C. The two phases that form are separated in the separator chamber 209 and further purification of t-BuCl can be accomplished, if desired, by distillation at 50° C. in chamber 213 with product being withdrawn via line 214 . HCl and H 2 O are withdrawn via line 210 and waste is discharged via line 212 . This thermal conversion reaction can be depicted by the following:
EXAMPLE 7
Photochemical Conversion Reaction
With reference to FIG. 6, dibenylketone (DBK) in benzene 301 (0.01 M) is metered via 302 and 303 into the photochemical reaction chamber 304 with at least one transparent wall, where it is irradiated with light 307 from a 450 watt xenon lamp 305 via filter 306 . The CO produced 310 , in the reaction 309 is vented and the dibenzyl product is purified, if desired, through a chromatographic separator 308 and withdrawn through line 309 . This photochemical conversion reaction can be depicted by the following:
EXAMPLE 8
Electrochemical Reduction Reaction
In FIG. 7, an acidic aqueous solution of benzoquinone (0.1 M) 401 is metered ( 402 , 403 ) into the cathodic chamber 416 of the electrochemical reactor 415 . This chamber, e.g. outside a Nafion hollow fiber tube containing the Pt anode and the analyte, contains a carbon or zinc cathode. Anode 408 a and cathode 408 b are connected to a power supply 407 . The current density and flow rate are controlled to maximize current efficiency as determined by analysis of hydroquinone by the electrochemical detector 417 . Hydroquinone 410 is extracted in extractor 409 from the resulting product stream with ether 414 metered ( 412 and 413 ) from ether supply 411 . Alternatively, flow in chamber 415 can be directed to the inner anode chamber with the appropriate controls. This electrochemical reduction reaction can be depicted by the following:
EXAMPLE 9
Enzyme-Catalyzed Conversion Reaction
In FIG. 8, the effluent 501 from a penicillin fermentation reactor containing benzylpencillin (BP) is fed through a filter bank 502 and 503 . An aqueous acid 505 is mixed with the filtered BP in mixer 506 and fed to membrane reactor 507 . The membrane reactor 507 is preferably a hollow fiber tube 511 on which the enzyme penicillin acylase has been immobilized. The tube also selectively extracts 6-aminopencillanic acid (6-APA) (see J. L. Lopez, S. L. Matson, T. J. Stanley, and J. A. Quinn, in “Extractive Bioconversions,” Bioprocess Technologies Series, Vol. 2, B. Masttgiasson and O. Holst. Eds., Marcel Dekker, N.Y., 1987). The BP is converted on the wall of the fiber and the product passes into the sweep stream inside the fiber where it can be purified by ion exchange 508 . The BP stream 510 is recycled back through the reactor. This enzyme catalyzed conversion reaction can be depicted by the following:
EXAMPLE 10
Catalytic Conversion Reaction
In FIG. 9, liquid n-heptane 601 is metered via 602 , 603 into the vaporizing chamber 604 held at 150° C. The vaporized heptane is then conveyed to the catalytic reactor 605 containing a packed bed of Pt/Al 2O 3 catalyst held at 400° C. Hydrogen is removed through line 606 . The heptane-toluene mixture from reactor 605 is fed to separator 608 with toluene being removed through line 609 and heptane through line 607 . This catalytic conversion reaction can be depicted by the following:
Although the invention has been described in conjunction with the specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirit and scope of the appended claims, further, the subject matter of the above cited United States Patents are incorporated herein by reference.
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A modular reactor system and method for synthesizing nanoscale quantities of chemical compounds characterized by a continuous flow reactor under high pressure having uniform temperature throughout the reaction mixture. The apparatus includes a number of generic components such as pumps, flow channels, manifolds, flow restrictors, valves and at least one modular reactor, as small as one nanoliter in volume, where larger quantities can be produced by either using larger nanoscale sized units or adding parallel and serially disposed nanoscale reactor units.
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The inventive methodology and associated apparatus relates to the liquefaction of normally gaseous material, most notably natural gas, and results in a reduction in the number of process vessels and associated space requirements over conventional technologies while incurring only a small decrease in process efficiency. The invention is particularly applicable to the liquefaction of natural gas at the small to intermediate scale where certain economies of scale associated with world-scale plants are lost or become much less significant.
BACKGROUND
Cryogenic liquefaction of normally gaseous materials is utilized for the purposes of component separation, purification, storage and for the transportation of said components in a more economic and convenient form. Most such liquefaction systems have many operations in common, regardless of the gases involved, and consequently, have many of the same problems. One problem commonly encountered is the number of process vessels and the costs and associated complexities attributable to the operation and maintenance of such vessels. These problems become more significant as world-scale liquefaction processes are scaled down and economies of scale are lost. Although the present invention will be described with specific reference to the processing of natural gas, the invention is applicable to the processing of normally gaseous materials in other systems wherein similar problems are encountered.
It is common practice in the art of processing natural gas to subject the gas to cryogenic treatment to separate hydrocarbons having a molecular weight greater than methane (C 2 +) from the natural gas thereby producing a pipeline gas predominating in methane and a C 2 + stream useful for other purposes. Frequently, the C 2 + stream will be separated into individual component streams, for example, C 2 , C 3 , C 4 and C 5 +.
It is also common practice to cryogenically treat natural gas to liquefy the same for transport and storage. The primary reason for the liquefaction of natural gas is that liquefaction results in a volume reduction of about 1/600, thereby making it possible to store and transport the liquefied gas in containers of more economical and practical design. For example, when gas is transported by pipeline from the source of supply to a distant market, it is desirable to operate the pipeline under a substantially constant and high load factor. Often the deliverability or capacity of the pipeline will exceed demand while at other times the demand may exceed the deliverability of the pipeline. In order to shave off the peaks where demand exceeds supply, it is desirable to store the excess gas in such a manner that it can be delivered when the supply exceeds demand, thereby enabling future peaks in demand to be met with material from storage. One practical means for doing this is to convert the gas to a liquefied state for storage and to then vaporize the liquid as demand requires.
Liquefaction of natural gas is of even greater importance in making possible the transport of gas from a supply source to market when the source and market are separated by great distances and a pipeline is not available or is not practical. This is particularly true where transport must be made by ocean-going vessels. Ship transportation in the gaseous state is generally not practical because appreciable pressurization is required to significantly reduce the specific volume of the gas which in turn requires the use of more expensive storage containers.
In order to store and transport natural gas in the liquid state, the natural gas is preferably cooled to -240° F. to -260° F. where it possesses a near-atmospheric vapor pressure. Numerous systems exist in the prior art for the liquefaction of natural gas or the like in which gas is liquefied by sequentially passing the gas at an elevated pressure through a plurality of cooling stages whereupon the gas is cooled to successively lower temperatures until the liquefaction temperature is reached. Cooling is generally accomplished by heat exchange with one or more refrigerants such as propane, propylene, ethane, ethylene, and methane or a combination of one or more of the preceding. In the art, the refrigerants are frequently arranged in a cascaded manner and each refrigerant is employed in a closed refrigeration cycle. Further cooling of the liquid is possible by expanding the liquefied natural gas to atmospheric pressure in one or more expansion stages. In each stage, the liquefied gas is flashed to a lower pressure thereby producing a two-phase gas-liquid mixture at a significantly lower temperature. The liquid is recovered and may again be flashed. In this manner, the liquefied gas is further cooled to a storage or transport temperature suitable for liquefied gas storage at near-atmospheric pressure. In this expansion to near-atmospheric pressure, some additional volumes of liquefied gas are flashed. The flashed vapors from the expansion stages are generally collected and recycled for liquefaction or utilized as fuel gas for power generation.
As previously noted, the present invention concerns the arrangement/selection of apparatus and associated process methodologies whereby the number of process vessels in each closed refrigeration cycle is significantly reduced. This factor becomes very important as the process is downsized (i.e., cooling duty in each cycle is reduced) whereupon economies of scale are lost. The invention results in both a reduction in the number of vessels and associated space requirements thereby reducing costs while incurring a relatively small reduction in process efficiency.
SUMMARY OF THE INVENTION
It is an object of this invention to reduce the number of process vessels required for liquefying normally gaseous material.
It is another object of this invention to reduce the space requirements of a process for liquefying normally gaseous material.
It is still yet another object of this invention to develop a process methodology and associated apparatus for liquefying normally gaseous material which is less capital intensive than alternative liquefaction methodologies.
In one embodiment of the invention, a normally gaseous stream is cooled and partially condensed by a process comprising the steps of (a) flowing said normally gaseous stream and a refrigerant stream through one or more brazed aluminum plate fin heat exchange sections wherein said streams are in indirect heat exchange with and flow countercurrent to one or more refrigeration streams wherein said one or more refrigeration streams are formed by (i) removing a sidestream from the refrigerant stream or portion thereof produced from one of said plate fin heat exchange sections, (ii) reducing the pressure of the sidestream thereby generating a refrigeration stream, and (iii) flowing said refrigeration stream to the heat exchange section from which said refrigerant stream of (i) was produced whereupon said refrigeration stream becomes one of said refrigeration stream of (a); (b) separately flowing the refrigerant stream from the last heat exchange section of (a) through a brazed aluminum plate fin heat exchange section wherein said stream is in indirect heat exchange with and flow countercurrent to a vapor refrigerant stream; (c) reducing the pressure of the refrigerant stream from the heat exchange section of step (b); (d) employing said stream of step (c) as a cooling agent on the kettle-side of a core-in-kettle heat exchanger thereby producing a vapor refrigerant stream; (e) warming the vapor refrigerant stream of (d) by flowing through at least the plate fin heat exchange section of (b); (f) compressing the refrigeration streams of step (a) and the warmed vapor refrigerant stream of step (e); (g) cooling the compressed stream of step (f) thereby producing the refrigerant stream of step (a); and (h) flowing the normally gaseous stream from step (a) through the core side of the core-in-kettle heat exchanger thereby producing a liquid-bearing stream.
In another embodiment, two or more of the plate fin heat exchanger sections in the previous embodiment are contained in a single brazed aluminum plate fin heat exchanger.
In yet another embodiment, the invention is comprised of an apparatus for performing the above-cited process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified flow diagram of a cryogenic LNG production process which illustrates the methodology and apparatus of the present invention.
FIGS. 2 and 3 illustrate embodiments of the invention wherein certain of the brazed aluminum plate fin heat transfer sections are combined in a single heat exchanger unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Because the processing of a natural gas stream is illustrative of the cooling of a normally gaseous material wherein preselected components are frequently removed from said stream and at least a portion of the stream liquefied and because this application is a preferred embodiment of the present invention, the following description with reference to the drawings will be confined to the processing of a natural gas stream. However, it is to be understood that the present invention is not confined to the processing of natural gas nor to the separation of components from a gas or the liquefaction of a gas, but relates broadly to the cooling of a normally gaseous material in general whereupon liquid product is produced and particularly, the multi-stage cooling of a normally gaseous material whereupon a liquid product is produced.
Natural Gas Stream Liquefaction
In the processing of natural gas, pretreatment steps are routinely employed for removing undesirable components such as acid gases, mercaptans, mercury and moisture from the natural gas feed stream delivered to the facility. The composition of this gas stream may vary significantly. As used herein, a natural gas stream is any stream principally comprised of methane which originates in major portion from a natural gas feed stream; for example a stream containing at least 85% methane by volume, with the balance being ethane, higher hydrocarbons, nitrogen, carbon dioxide and a minor amounts of other contaminants such as mercury, hydrogen sulfide, mercaptans. The pretreatment steps may be separate steps located either upstream of the cooling cycles or located downstream of one of the early stages of cooling in the initial cycle. The following is a non-inclusive listing of some of the available means which are readily available to one skilled in the art. Acid gases and to a lesser extent mercaptans are routinely removed via a sorption process employing an aqueous amine-bearing solution. This treatment step is generally performed upstream of the cooling stages employed in the initial cycle. A major portion of the water is routinely removed as a liquid via two-phase gas-liquid separation following gas compression and cooling upstream of the initial cooling cycle and also downstream of the first cooling stage in the initial cooling cycle. Mercury is routinely removed via mercury sorbent beds. Residual amounts of water and acid gases are routinely removed via the use of properly selected sorbent beds such as regenerable molecular sieves. Processes employing sorbent beds are generally located downstream of the first cooling stage in the initial cooling cycle.
One of the most efficient and effective methodologies for natural gas liquefaction is a cascade-type operation and this type in combination with expansion-type cooling. Also, since methods for the production of liquefied natural gas (LNG) include the separation of hydrocarbons of molecular weight greater than methane as a first part thereof, a description of a plant for the cryogenic production of LNG effectively describes a similar plant for removing C 2 + hydrocarbons from a natural gas stream.
In the preferred embodiment which employs a cascaded refrigerant system, the invention concerns the sequential cooling of a natural gas stream at an elevated pressure, for example about 650 psia, by sequentially cooling the gas stream by passage through a multistage propane cycle, a multistage ethane or ethylene cycle and either (a) a closed methane cycle followed by a single- or a multistage expansion cycle to further cool the same and reduce the pressure to near-atmospheric or (b) an open-end methane cycle which utilizes a portion of the feed gas as a source of methane and which includes therein a multistage expansion cycle to further cool the same and reduce the pressure to near-atmospheric pressure. In the sequence of cooling cycles, the refrigerant having the highest boiling point is utilized first followed by a refrigerant having an intermediate boiling point and finally by a refrigerant having the lowest boiling point.
The natural gas stream is generally delivered to the liquefaction process at an elevated pressure or is compressed to an elevated pressure, that being a pressure greater than 500 psia, preferably about 500 to about 900 psia, still more preferably about 550 to about 675 psia, still yet more preferably about 575 to about 650 psia, and most preferably about 600 psia. The stream temperature is typically near ambient to slightly above ambient. A representative temperature range being 60° F. to 120° F.
As previously noted, the natural gas stream at this point is cooled in a plurality of multistage (for example, three) cycles or steps by indirect heat exchange with a plurality of refrigerants, preferably three. The overall cooling efficiency for a given cycle improves as the number of stages increases but this increase in efficiency is accompanied by corresponding increases in net capital cost and process complexity. The feed gas is preferably passed through an effective number of refrigeration stages, nominally two, preferably two to four, and more preferably three stages, in the first closed refrigeration cycle utilizing a relatively high boiling refrigerant. Such refrigerant is preferably comprised in major portion of propane, propylene or mixtures thereof, more preferably propane, and most preferably the refrigerant consists essentially of propane. Thereafter, the processed feed gas flows through an effective number of stages, nominally two, preferably two to four, and more preferably two or three, in a second closed refrigeration cycle in indirect heat exchange with a refrigerant having a lower boiling point. Such refrigerant is preferably comprised in major portion of ethane, ethylene or mixtures thereof, more preferably ethylene, and most preferably the refrigerant consists essentially of ethylene. Each of the above-cited cooling stages for each refrigerant comprises a separate cooling zone.
Generally, the natural gas feed stream will contain such quantities of C 2 + components so as to result in the formation of a C 2 + rich liquid in one or more of the cooling stages. This liquid is removed via gas-liquid separation means, preferably one or more conventional gas-liquid separators. Generally, the sequential cooling of the natural gas in each stage is controlled so as to remove as much as possible of the C 2 and higher molecular weight hydrocarbons from the gas to produce a first gas stream predominating in methane and a second liquid stream containing significant amounts of ethane and heavier components. An effective number of gas/liquid separation means are located at strategic locations downstream of the cooling zones for the removal of liquids streams rich in C 2 + components. The exact locations and number of gas/liquid separation means will be dependant on a number of operating parameters, such as the C 2 + composition of the natural gas feed stream, the desired BTU content of the final product, the value of the C 2 + components for other applications and other factors routinely considered by those skilled in the art of LNG plant and gas plant operation. The C 2 + hydrocarbon stream or streams may be demethanized via a single stage flash or a fractionation column. In the former case, the methane-rich stream can be repressurized and recycled or can be used as fuel gas. In the latter case, the methane-rich stream can be directly returned at pressure to the liquefaction process. The C 2 + hydrocarbon stream or streams or the demethanized C 2 + hydrocarbon stream may be used as fuel or may be further processed such as by fractionation in one or more fractionation zones to produce individual streams rich in specific chemical constituents (ex., C 2 , C 3 , C 4 and C 5 +). In the last stage of the second cooling cycle, the gas stream which is predominantly methane (typically greater than 95 mol % methane and more typically greater than 97 mol % methane) is condensed (i.e., liquefied) in major portion, preferably in its entirety.
The liquefied natural gas stream is then further cooled in a third step by one of two embodiments. In one embodiment, the liquefied natural gas stream is further cooled by indirect heat exchange with a third closed refrigeration cycle wherein the condensed gas stream is subcooled via passage through an effective number of stages, nominally 2; preferably 2 to 4; and most preferably 3 wherein cooling is provided via a third refrigerant having a boiling point lower than the refrigerant employed in the second cycle. This refrigerant is preferably comprised in major portion of methane, still more preferably is greater than 90 mol % methane, and most preferably consists essentially of methane. In the second and preferred embodiment which employs an open methane refrigeration cycle, the liquefied natural gas stream is subcooled via indirect heat exchange with flash gases in a main methane economizer in a manner to be described later.
In the fourth step, the liquefied gas is further cooled by expansion and separation of the flash gas from the cooled liquid. In a manner to be described, nitrogen removal from the system and the condensed product is accomplished either as part of this step or in a separate succeeding step. A key factor distinguishing the closed cycle from the open cycle is the initial temperature of the liquefied stream prior to flashing to near-atmospheric pressure, the relative amounts of flashed vapor generated upon said flashing, and the disposition of the flashed vapors. Whereas the majority of the flash vapor is recycled to the methane compressors in the open-cycle system, the flashed vapor in a closed-cycle system is generally utilized as a fuel.
In the fourth step in either the open- or closed-cycle methane systems, the liquefied product is cooled via at least one, preferably two to four, and more preferably three expansions where each expansion employs either Joule-Thomson expansion valves or hydraulic expanders followed by a separation of the gas-liquid product with a separator. As used herein, the term "hydraulic expands" is not limited to an expander which receives and produces liquid streams but is inclusive of expanders which receive a predominantly liquid-phase stream and produce a two-phase (gas/liquid) stream. When a hydraulic expander is employed and properly operated, the greater efficiencies associated with the recovery of power, a greater reduction in stream temperature, and the production of less vapor during the expansion step will frequently be cost-effective even in light of increased capital and operating costs associated with the expander. In one embodiment employed in the open-cycle system, additional cooling of the high pressure liquefied product prior to flashing is made possible by first flashing a portion of this stream via one or more hydraulic expanders and then via indirect heat exchange means employing said flashed stream to cool the high pressure liquefied stream prior to flashing. The flashed product is then recycled via return to an appropriate location, based on temperature and pressure considerations, in the open methane cycle.
When the liquid product entering the fourth cycle is at the preferred pressure of about 600 psia, representative flash pressures for a three stage flash process are about 190, 61 and 14.7 psia. In the open-cycle system, vapor flashed or fractionated in the nitrogen separation step to be described and that flashed in the expansion flash steps are utilized as cooling agents in the third step or cycle which was previously mentioned. In the closed-cycle system, the vapor from the flash stages may also be employed as a cooling agent prior to either recycle or use as fuel. In either the open- or closed-cycle system, flashing of the liquefied stream to near atmospheric pressure will produce an LNG product possessing a temperature of -240° F. to -260° F.
To maintain the BTU content of the liquefied product at an acceptable limit when appreciable nitrogen exists in the feed stream, nitrogen must be concentrated and removed at some location in the process. Various techniques for this purpose are available to those skilled in the art. The following are examples. When an open methane cycle is employed and nitrogen concentration in the feed is low, typically less than about 1.0 vol %, nitrogen removal is generally achieved by removing a small side stream at the high pressure inlet or outlet port at the methane compressor. For a closed cycle at nitrogen concentrations of up to 1.5 vol. % in the feed gas, the liquefied stream is generally flashed from process conditions to near-atmospheric pressure in a single step, usually via a flash drum. The nitrogen-bearing flash vapors are then generally employed as fuel gas for the gas turbines which drive the compressors. The LNG product which is now at near-atmospheric pressure is routed to storage. When the nitrogen concentration in the inlet feed gas is about 1.0 to about 1.5 vol % and an open-cycle is employed, nitrogen can be removed by subjecting the liquefied gas stream from the third cooling cycle to a flash step prior to the fourth cooling step. The flashed vapor will contain an appreciable concentration of nitrogen and may be subsequently employed as a fuel gas. A typical flash pressure for nitrogen removal at these concentrations is about 400 psia. When the feed stream contains a nitrogen concentration of greater than about 1.5 vol % and an open or closed cycle is employed, the flash step may not provide sufficient nitrogen removal. In such event, a nitrogen rejection column will be employed from which is produced a nitrogen rich vapor stream and a liquid stream. In a preferred embodiment which employs a nitrogen rejection column, the high pressure liquefied methane stream to the methane economizer is split into a first and second portion. The first portion is flashed to approximately 400 psia and the two-phase mixture is fed as a feed stream to the nitrogen rejection column. The second portion of the high pressure liquefied methane stream is further cooled by flowing through a methane economizer to be described later, it is then flashed to 400 psia, and the resulting two-phase mixture or the liquid portion thereof is fed to the upper section of the column where it functions as a reflux stream reflux. The nitrogen-rich vapor stream produced from the top of the nitrogen rejection column will generally be used as fuel. The liquid stream produced from the bottom of the column is then fed to the first stage of methane expansion.
Refrigerative Cooling for Natural Gas Liquefaction
Critical to the liquefaction of natural gas in a cascaded process is the use of one or more refrigerants for transferring heat energy from the natural gas stream to the refrigerant and ultimately transferring said heat energy to the environment. In essence, the refrigeration system functions as a heat pump by removing thermal energy from the natural gas stream as the stream is progressively cooled to lower and lower temperatures. In so doing, the thermal energy removed from the natural gas stream is ultimately rejected (pumped) to the environment via energy exchange with one or more refrigerants.
The liquefaction process employs several types of cooling which include but are not limited to (a) indirect heat exchange, (b) vaporization and (c) expansion or pressure reduction. A key aspect of this invention is the manner in which indirect heat exchange is employed. Indirect heat exchange, as used herein, refers to a process wherein the refrigerant or cooling agent cools the substance to be cooled without actual physical contact between the refrigerating agent and the substance to be cooled. Specific examples include heat exchange undergone in a tube-and-shell heat exchanger, a core-in-kettle heat exchanger, and a brazed aluminum plate-fin heat exchanger. The current invention is distinguished over conventional methodologies by the novel and strategic use of brazed aluminum plate-fin heat exchangers in place of certain of the core-in-kettle heat exchangers thereby resulting in a reduction in the number of process vessels and associated space requirements while incurring only a relatively small decrease in process efficiency. As previously noted, these factors become increasingly more important as the process is downsized and economies of scale are lost for certain of the process vessels.
A second form of cooling which may be employed is vaporization cooling. Vaporization cooling refers to the cooling of a substance by the evaporation or vaporization of a portion of the substance with the system maintained at or near a constant pressure. Thus during vaporization cooling, the portion of the substance which evaporates absorbs heat from the portion of the substance which remains in a liquid state and hence, cools the liquid portion.
The third means of cooling which may be employed is expansion or pressure reduction cooling. Expansion or pressure reduction cooling refers to cooling which occurs when the pressure of a gas-, liquid- or a two-phase system is decreased by passing through a pressure reduction means. In one embodiment, this expansion means is a Joule-Thomson expansion valve. In another embodiment, the expansion means is a hydraulic expander or a gas expander. Because expanders recover work energy from the expansion process, lower process stream temperatures are possible upon expansion.
In the discussion and drawings to follow, the discussions or drawings may depict the expansion of a refrigerant by flowing through a throttle valve followed by a subsequent separation of gas and liquid portions on the kettle-side of a core-in-kettle heat exchanger. In an alternative embodiment, the throttle or expansion valve may not be a separate item connected by conduit to the core-in-kettle heat exchanger but rather an integral part of the core-in-kettle heat exchanger (i.e., the flash or expansion occurs upon entry of the liquefied refrigerant into the kettle-side of the core-in-kettle heat exchanger). Additionally, multiple streams may be cooled in a single core-in-kettle heat exchanger by the placement of multiple cores in a single kettle. The drawings and discussions may also address separating or splitting means wherein a given stream is partitioned into two or more streams. Such means for separating or splitting a stream are inclusive of those means routinely employed by those skilled in the art and include but are not limited to t's, y's and other piping arrangements with associated flow control mechanisms routinely employed in the splitting or separating of such streams and the employment of vessels possessing at least one inlet port and two or more outlet ports and associated flow control mechanisms routinely employed by those skilled in the art.
In the first cooling cycle in a cascaded cooling process, cooling is provided by the compression of a higher boiling point gaseous refrigerant, preferably propane, to a pressure where it can be liquefied by indirect heat transfer with a heat transfer medium which ultimately employs the environment as a heat sink, that heat sink generally being the atmosphere, a fresh water source, a salt water source, the earth or two or more of the preceding. The condensed refrigerant then undergoes one or more steps of expansion cooling via suitable expansion means thereby producing two-phase mixtures possessing significantly lower temperatures which are employed as cooling agents, also referred to herein as refrigeration streams. In the first cooling cycle, the refrigeration stream cools and condenses at least the second cycle refrigerant stream (a normally gaseous stream) and cools one or more methane-rich gas streams (ex., the natural gas stream).
In a similar manner in the second cooling cycle of a cascaded cooling process, cooling is provided by the compression of a refrigerant having a boiling point less than the refrigerant in the first cycle, preferably ethane or ethylene, most preferably ethylene, to a pressure where it is subsequently liquefied via contact with among other cooling mediums, the refrigerating agent from the first cycle. The condensed refrigerant stream then undergoes one or more steps of expansion cooling via suitable expansion means thereby producing two-phase mixtures possessing significantly lower temperatures which are employed as cooling agents, also referred to herein as refrigeration streams. These cooling agents or refrigeration streams are then employed to cool and at least partially condensed, preferably condense in major portion, at least one methane-rich gas stream.
When employing a three refrigerant cascaded closed cycle system, the refrigerant in the third cycle is compressed in a stagewise manner, preferably though optionally cooled via indirect heat transfer to an environmental heat sink (i.e., inter-stage and/or post-cooling following compression) and then cooled by indirect heat exchange with either all or selected cooling stages in the first and second cooling cycles which preferably employ propane and ethylene as respective refrigerants. Preferably, this stream is contacted in a sequential manner with each progressively colder stage of refrigeration in the first and second cooling cycles, respectively.
In an open-cycle cascaded refrigeration system such as that illustrated in FIG. 1, the first and second cycles are operated in a manner analogous to that set forth for the closed cycle. However, the open methane cycle system is readily distinguished from the conventional closed refrigeration cycles. As previously noted in the discussion of the fourth step, a significant portion of the liquefied natural gas stream (i.e., methane-rich gas stream) originally present at elevated pressure is cooled to approximately -260° F. by expansion cooling in a stepwise manner to near-atmospheric pressure. In each step, significant quantities of methane-rich vapor at a given pressure are produced. Each vapor stream preferably undergoes significant heat transfer in methane economizers and is preferably returned to the inlet port of the open methane cycle compressor for the stage of interest at near-ambient temperature. In the course of flowing through the methane economizers, the flashed vapors are contacted with warmer streams in a countercurrent manner and in a sequence designed to maximize the cooling of the warmer streams. The pressure selected for each stage of expansion cooling is such that for each stage, the volume of gas generated plus the compressed volume of vapor from the adjacent lower stage results in efficient overall operation of the open methane cycle multi-stage compressor. Interstage cooling and cooling of the final compressed gas is preferred and preferably accomplished via indirect heat exchange with one or more cooling agents directly coupled to an environmental heat sink. The compressed methane-rich stream is then further cooled via indirect heat exchange with refrigerant in the first and second cycles, preferably all stages associated with the refrigerant employed in the first cycle, more preferably the first two stages and most preferably, only the first stage. The cooled methane-rich stream is further cooled via indirect heat exchange with flash vapors in the main methane economizer and is then combined with the natural gas feed stream at a location in the liquefaction process where the natural gas feed stream and the cooled methane-rich stream are at similar conditions of temperature and pressure.
In one embodiment, the cooled methane stream is combined with the natural gas stream immediately prior to the ethylene cooling stage wherein said combined stream is liquefied in major portion (i.e., ethylene condenser), that stage preferably being the last stage of cooling in the second cycle. In another more preferred embodiment, the methane-rich stream is progressively cooled in the methane economizer with portions of the stream removed and combined with the natural gas stream or the resulting combined natural gas/methane-rich stream, as the case may be, at strategic locations upstream of the various stages of cooling in the second cycle whereat the temperatures of the streams to be combined are in close proximity to one another. A preferred embodiment of this methodology is illustrated in FIG. 1 wherein two stages of cooling are employed in the second cycle. The methane-rich stream is cooled to a first temperature in the methane economizer and a sidestream is removed which is combined with the natural gas stream upstream of the first stage of cooling in the second cycle thereby forming a first natural gas-bearing stream. The remaining portion of the methane-rich stream is further cooled in the economizer and combined with the first natural gas-bearing stream which has also undergone further cooling immediately upstream of the second stage of cooling in the second cycle thereby forming a second natural gas-bearing stream.
Inventive Embodiment
A key aspect of the current invention is the methodology and apparatus employed for cooling normally gaseous material in the first and second cycles of a cascaded refrigeration process and further, the ability to return refrigeration streams to their respective compressors at near ambient temperatures thereby avoiding or significantly reducing the exposure of key compressor components to cryogenic conditions. Such is done without the expense of additional heat exchangers, sometimes referred to as economizers, which function to raise the temperature of the respective refrigerant streams to near ambient temperatures prior to compression.
In the description which follows, reference will be made to countercurrent flow and counterflow of fluids through passages in brazed aluminum plate fin heat exchange sections. Countercurrent flow as used herein is inclusive of counterflow, cross-counterflow and combinations thereof as such terminologies are employed by the Brazed Aluminum Plate-Fin Heat Exchanger Manufacturers' Association and as set forth in The Standards of the Brazed Aluminum Plate-Fin Heat Exchanger Manufacturers' Association, First Edition (1994) which is hereby incorporated by reference. When discussing flow through brazed aluminum plate fin heat exchange sections or brazed aluminum plate fin heat exchangers reference will be made to a "passage". Such reference is not limited to a single passage, but rather is inclusive of the plurality of flow passages available to a given stream when flowing through said exchanger section or exchanger.
In one embodiment of the invention, a normally gaseous stream is cooled and partially condensed by a process comprising the steps of (a) flowing said normally gaseous stream and a refrigerant stream through one or more brazed aluminum plate fin heat exchange sections wherein said streams are in indirect heat exchange with and flow countercurrent to one or more refrigeration streams wherein said one or more refrigeration streams are formed by (i) removing via a splitting means a sidestream from the refrigerant stream or remaining portion thereof flowing through said one of said plate fin heat exchange sections, (ii) reducing via a pressure reduction means the pressure of the sidestream thereby generating a refrigeration stream, and (iii) flowing said refrigeration stream to said plate fin heat exchange section at a location in close proximity to said location of sidestream removal of (i) and then through the plate fin heat exchange section of (a) as a refrigeration stream, (b) separately flowing the refrigerant stream from the last heat exchange section of (a) through a brazed aluminum plate fin heat exchange section wherein said stream is in indirect heat exchange with and flows countercurrent to a vapor refrigerant stream; (c) reducing via a pressure reduction means the pressure of the refrigerant stream from the heat exchange section of step (b); (d) employing said stream of step (c) as a cooling agent on the kettle-side of a core-in-kettle heat exchanger thereby producing a vapor refrigerant stream; (e) warming the vapor refrigerant stream of (d) by flowing through at least the plate fin heat exchange section of (b); (f) compressing via a compressor the refrigeration streams of step (a) and the warmed vapor refrigerant stream of step (e); (g) cooling via a condenser the compressed stream of step (f) thereby producing the refrigerant stream of step (a); and (h) flowing the normally gaseous stream of step (a) through the core side of the core-in-kettle heat exchanger thereby producing a liquid-bearing stream. The preceding assumes necessary conduits are in place to enable the flow of identified streams between the identified elements.
In a preferred embodiment, the preceding process is additionally comprised of flowing the warmed vapor refrigerant stream of step (e) through one or more of the heat exchange sections of step (a) wherein said stream flows countercurrent to said refrigerant stream in said heat exchange section prior to the compression step of (f). The compressor is preferably designed for hydrocarbon service and more preferably for the compression of ethane, ethylene or propane. The preferred normally gaseous stream is predominantly methane and the preferred refrigerant is predominantly ethane or ethylene, more preferably consists essentially of ethane, ethylene or a mixture thereof and most preferably consists essentially of ethylene. When the heat exchange sections are individual exchangers, the heat exchange section of step (b) is preferably comprised of a core and two inlet and two outlet headers to the core where the inlet and outlet headers are situated in such a manner as to provide for countercurrent flow of the two fluid streams. Similarly, the heat exchange section or sections of step (a) is preferably comprised of a core and inlet and outlet headers to the core where the headers are attached to the core in such a manner as to provide for the countercurrent flow, more preferably counterflow, of these two fluid streams (ex., refrigerant stream and normally gaseous stream) relative to one or more refrigeration streams. In a more preferred embodiment which is particularly applicable to cooling in the first cycle, the heat exchange section of (a) is preferably comprised of a core and inlet and outlet headers to such core which provide for the countercurrent flow, more preferably counterflow, of three streams, those steams preferably being two normally gaseous streams and a refrigerant stream, relative to two streams, those streams preferably being two refrigeration streams.
In another even more preferred embodiment, the plate fin heat exchange sections employed in steps (a) and optionally (b) are contained in a single brazed aluminum plate fin heat exchanger. One such apparatus for cooling a normally gaseous stream employing the exchanger sections of steps (a) and (b) in a single brazed aluminum plate fin heat exchanger is an apparatus comprised of (a) a compressor; (b) a condenser; (c) a core-in-kettle heat exchanger; (d) at least two pressure reduction means; (e) a brazed aluminum plate fin heat exchanger comprised of (i) at least two inlet headers and at least one outlet header situated in close proximity to one another at or near one end of the plate fin heat exchanger, (ii) a least one inlet header and at least one outlet header situated in close proximity to one another at or near the end opposing that set forth in (i), (iii) at least one intermediate inlet header and at least one intermediate outlet header wherein said headers are situated along the exchanger between the headers of (i) and (ii), (iv) a core comprised of (aa) at least one flow passage connecting one of said inlet headers of (i), an outlet header of (ii) and at least one intermediate outlet header of (iii), (bb) at least one flow passage between one of the inlet headers of (ii) and either an intermediate outlet header of (iii) or an outlet header of (i), (cc) at least one flow passage between one of said intermediate inlet headers of (iii) and at least one outlet header of (i), and (dd) at least one flow passage between the inlet header of (i) and either an intermediate outlet header of (iii) or an outlet header of (ii); (f) a conduit connecting the compressor to the condenser; (g) a conduit connecting the condenser to said inlet header of (i) which is in flow communication with at least one intermediate outlet header of (iii); (h) conduits connecting each of the intermediate outlet header in flow communication with the inlet header employed in (g) to a pressure reduction means and connecting each pressure reduction means to an intermediate inlet header; (I) conduits connecting the outlet headers of (i) and the headers of (bb) to the compressor; (j) a conduit connecting the outlet header of (ii) which is in flow communication with the intermediate outlet headers to a pressure reduction means; (k) a means to insure flow communication between the pressure reduction means of (j) and the kettle-side of the core-in-kettle heat exchanger; (l) conduit connecting said kettle-side of the core-in-kettle heat exchanger to one of said inlet headers employed in (bb); (m) a conduit connected to one of said remaining inlet headers of (i); (n) conduit connecting the outlet header of (dd) or intermediate outlet header of (dd) which is in flow communication with the conduit of (m) to the core in the core-in-kettle heat exchanger; and (o) conduit connected to the exit section of the core in the core-in-kettle heat exchanger wherein said conduit extends external to the kettle.
In another preferred embodiment, the preceding apparatus is further comprised of (p) one or more additional intermediate outlet headers situated between the intermediate headers of (iii) and the outlet headers of (ii) wherein said headers are connected to the passage of (aa); (q) one or more additional intermediate inlet headers were one each of such headers are located on the plate fin heat exchanger in close proximity to an intermediate outlet header of (p); (r) a conduit, pressure reduction means, and conduit providing flow communication between each header of (p) and (q) which are in spacial proximity to one another; (s) for each intermediate inlet header of (q), an outlet header in close proximity to the headers of (i) or an intermediate outlet header situated along said plate fin heat exchanger between the header of (i) and said intermediate inlet header of (q); and (t) a core further comprised of passages connecting each such intermediate inlet header of (q) to the corresponding intermediate outlet header of (s) wherein the conduit of (I) is further comprised of such conduit necessary to connect the outlet headers of (s) to the compressor.
In the current invention, the functionality performed by the economizers in the prior art can be obtained by providing the requisite heat transfer area and associated cooling passages in the brazed aluminum plate fin heat exchange sections employed in the first and second cycles. In this manner, overall efficiencies are improved and problems associated with the exposure of key compressor components to cryogenic conditions are avoided. The current inventive embodiment still maintains a main methane economizer, but this too make take the form of a brazed aluminum plate fin heat exchanger.
Preferred Open-Cycle Embodiment of Cascaded Liquefaction Process
The flow schematic and apparatus set forth in FIGS. 1-3 is a preferred embodiment of the invention when employed in an open-cycle cascaded liquefaction process and is set forth for illustrative purposes. Purposely missing from the preferred embodiment is a nitrogen removal system, because such system is dependant on the nitrogen content of the feed gas. However as noted in the previous discussion of nitrogen removal technologies, methodologies applicable to this preferred embodiment are readily available to those skilled in the art. Those skilled in the art will also recognized that FIGS. 1-3 are schematics and therefore, many items of equipment that would be needed in a commercial plant for successful operation have been omitted for the sake of clarity. Such items might include, for example, compressor controls, flow and level measurements and corresponding controllers, additional temperature and pressure controls, pumps, motors, filters, additional heat exchangers, valves, etc. These items would be provided in accordance with standard engineering practice.
The first cycle in the cascaded refrigeration process is illustrative of a method and apparatus employing three stages of refrigerative cooling for cooling and liquefying a normally gaseous material. The refrigerant from the second cycle is condensed in this stage and several methane-rich streams, including the natural gas stream, are cooled in this cycle. The second cycle in the cascaded refrigeration process is illustrative of a method and apparatus employing two stages of refrigerative cooling for cooling and liquefying a normally gaseous material.
To facilitate an understanding of FIGS. 1-3, items numbered 1 thru 99 generally correspond to process vessels and equipment directly associated with the liquefaction process. Items numbered 100 thru 199 correspond to flow lines or conduits which contain methane in major portion. Items numbered 200 thru 299 correspond to flow lines or conduits which contain the refrigerant ethylene or optionally, ethane. Items numbered 300 thru 399 correspond to flow lines or conduits which contain the refrigerant propane. Items numbered 400 through 499 correspond to items associated with the brazed aluminum plate fin heat exchange sections; when one or more such sections comprise a single heat exchanger.
Referring to FIG. 1, gaseous propane is compressed in multistage compressor 18 driven by a gas turbine driver which is not illustrated. The three stages of compression preferably exist in a single unit although each stage of compression may be a separate unit and the units mechanically coupled to be driven by a single driver. Upon compression, the compressed propane is passed through conduit 300 to cooler 16 where it is liquefied. A representative pressure and temperature of the liquefied propane refrigerant prior to flashing is about 100° F. and about 190 psia. Although not illustrated in FIG. 1, it is preferable that a separation vessel be located downstream of cooler 16 and upstream of the high stage propane brazed aluminum plate fin heat exchanger 2, for the removal of residual light components from the liquefied propane and to provide surge control for the system. Such vessels may be comprised of a single-stage gas-liquid separator or may be more sophisticated and comprised of an accumulator section, a condenser section and an absorber section, the latter two of which may be continuously operated or periodically brought on-line for removing residual light components from the propane. The refrigerant stream from this vessel or the stream from cooler 16, as the case may be, is passed through conduit 302 to a high stage propane brazed aluminum plate fin heat exchange section 2 wherein said stream flows through core passages 10 wherein indirect heat exchange occurs. The cooled or second refrigerant stream is produced via conduit 303. This stream is then split via a splitting or separation means (illustrated but not numbered) into two portions, third and fourth refrigerant streams, and produced via conduits 304 and 307. The third refrigerant stream via conduit 304 flows to a pressure reduction means, illustrated as expansion valve 14, wherein the pressure of the liquefied propane is reduced thereby evaporating or flashing a portion thereof and thereby producing a high stage refrigeration stream. This stream then flows through conduit 305 and through core passages 12 wherein said stream flows countercurrent to the streams in passage 10 and yet to be described streams in passages 4, 6, and 8 and wherein indirect heat exchange occurs. This stream, the high stage recycle stream, is routed via conduit 306 to the high stage inlet port at propane compressor 18. In the course of such routing, the stream will generally pass through a suction scrubber. Also fed to plate fin heat exchange section 2 are the natural gas stream via conduit 100, a gaseous ethylene stream via conduit 202 and a methane-rich stream via conduit 152. These streams in flow passages 6, 8 and 4 and the refrigerant stream in passage 10 flow countercurrent, more preferably counterflow, to the stream in passage 12. Indirect heat exchange occurs between such streams. The streams respectively flowing in passages 4, 6, and 8 are produced via conduits 102, 204, and 154. The stream in conduit 204 will be referred to as a first cooled stream.
The cooled natural gas stream in conduit 102, the first cooled stream in conduit 204 and the fourth refrigerant stream in conduit 307 respectively flow through passages 22, 24, and 25 in brazed aluminum plate fin heat exchange section 20 countercurrent, more preferably counterflow, to a yet to be identified refrigeration stream thereby producing a further cooled natural gas stream, a second cooled stream, and a fifth refrigerant stream which are produced via conduits 110, 206 and 308. The fifth refrigerant stream is then split via a splitting or separation means (illustrated but not numbered) into two portions, the sixth and seventh refrigerant streams, and respectively produced via conduits 309 and 312. The sixth refrigerant via conduit 309 flows to a pressure reduction means, illustrated as expansion valve 27, wherein the pressure of the liquefied propane is reduced thereby evaporating or flashing a portion thereof thereby producing a intermediate-stage refrigeration stream. This stream then flows through conduit 310 and through core passage 26 wherein said stream flows countercurrent to the steams in passages 22, 24 and 25 and wherein indirect heat exchange occurs. The resulting stream is produced as an intermediate stage recycle stream via conduit 311. This stream is returned to the intermediate stage inlet port at propane compressor 18, again preferably after passing through a suction scrubber.
The further cooled natural gas stream and the second cooled stream are respectively routed via conduits 110 and 206 to respective cores 36 and 38 in core-in-kettle heat exchanger 34 wherein said natural gas stream is yet further cooled and said second cooled stream is liquefied in major portion. The streams are respectively produced via conduits 112 and 208.
The seventh refrigerant stream in conduit 312 is connected to brazed aluminum plate fin heat exchange section 28 wherein said stream flows via passage 29 countercurrent, more preferably counterflow, to and in indirect heat exchange with a low stage refrigeration fluid flowing via passage 30 thereby producing an eighth refrigerant stream via conduit 314. The eighth refrigerant via conduit 314 flows to a pressure reduction means, illustrated as expansion valve 32, wherein the pressure of the liquefied propane is reduced thereby evaporating or flashing a portion thereof thereby producing a two-phase refrigerant refrigeration stream. As previously noted, the pressure reduction step can take place via a valve with conduit (illustrated as 316) connecting the valve to the core-in-kettle heat exchanger or upon entrance to the core-in-kettle heat exchanger. The two-phase refrigeration stream is then employed as a cooling agent on the kettle-side of core-in-kettle heat exchanger 34 wherein the stream is partitioned into gas and liquid portions and said cores are at least partially submerged in the liquid portion. Removed from the kettle-side of said exchanger via conduit 318 is a low stage refrigeration stream. This conduit is connected to passage 30 in heat exchanger section 28 wherein said stream flows countercurrent and is in indirect heat exchange with the seventh refrigerant stream in passage 29 thereby producing a low stage recycle stream. The low stage recycle stream is then returned to the low-stage inlet port at compressor 18 preferably after flow through a suction scrubber via conduit 320 where said stream is compressed thereby becoming a compressed low-stage recycle stream, combined with the intermediate-stage recycle stream to form a combined intermediate-stage stream and compressed to form a compressed intermediate stage recycle stream. This stream is then combined with the high stage recycle stream to form a combined high stage recycle stream which is compressed to form a compressed refrigerant stream produced via conduit 300.
In one embodiment of the invention, the brazed aluminum plate fin heat exchange sections 2, 20, and 28 set forth above are separate heat exchangers. In another embodiment, the heat exchange sections are combined into one or more exchangers. Although resulting in a more complex heat exchanger which possesses intermediate headers, this approach offers advantages from a lay-out and cost perspective. The following embodiment wherein the heat exchanger sections are contained in a single heat exchange section is a preferred embodiment.
With regard to nomenclature, reference in the ensuing discussion will be made to first-stream, second-stream, third-stream, fourth-stream, fifth-stream and sixth-stream elements. An example to such reference is the terminology "first-stream intermediate header". In this context, reference is being made to a given element, that being an intermediate header, to which is directed at least a portion of a given flow stream, that being the first-stream. Therefore, first-stream inlet header, first-stream intermediate header and first-stream outlet header refer to headers which are connected to a common flow passage in a plate fin heat exchanger through which the first stream may flow.
In the above-cited preferred embodiment, a brazed aluminum plate fin heat exchanger is employed which is schematically depicted in FIG. 2. The depicted exchanger is comprised of (i) first-, second- and third-stream inlet headers (450, 451, 452) and a fourth-stream outlet header 453 located in close proximity to one another near one end of the plate fin heat exchanger 495; (ii) a third-streatm outlet header 458 and sixth-stream inlet header 462 located in close proximity to one another near the end opposing that set forth in (i); (iii) third-, fourth- and fifth-stream intermediate headers of (iii) (456, 459, 461) spatially located along the exchanger between the headers of (i) and (ii) and in spacial proximity to one another; (iv) first-, second-, third-, fifth- and sixth-stream intermediate headers of (iv) (454, 455, 457, 460, 463) spatially located along the exchanger between the headers of (iii) and the headers of (ii); and (v) a core within the plate fin heat exchanger comprised of at least one heat exchange conduit (i.e. passage) 470 connecting the first-stream inlet header 450 and the first-stream intermediate header of (iv) 454, at least one heat exchange conduit 471 connecting the second-stream inlet header 451 and to the second-stream intermediate header of (iv) 455, at least one heat exchange conduit connecting the third-stream inlet header 452, the third-stream intermediate header of (iii) 456, the third-stream intermediate header of (iv) 457 and the third-stream outlet header 458 (such conduits illustrated in FIG. 2 as 472, 473 and 474), at least one heat exchange conduit 475 connecting the fourth-stream intermediate header 459 to the fourth-stream outlet header 453, at least one heat exchange conduit 476 connecting the fifth-stream intermediate header of (iv) 460 to the fifth-stream intermediate header of (iii) 461, and at least one heat exchange conduit 477 connecting the sixth-stream inlet header 462 to the sixth stream intermediate header of (iv) 463. This embodiment is additionally comprised of two pressure reduction means 14 and 27. Pressure reduction means 14 is respectively connected via conduit 304 to the third-stream intermediate header of (iii) 456 and via conduit 305 to the fourth stream intermediate header of (iii) 459. Pressure reduction means 27 is respectively connected via conduit 309 to the third-stream intermediate header of (iv) 457 and via conduit 310 to the fifth intermediate header of (iv) 460. In this embodiment, conduit 100 is connected to the first-stream inlet header 450, conduit 202 is connected to the second-stream inlet header 451, conduit 302 is connected to the third-stream inlet header 452, conduit 306 is connected to the fourth-stream outlet header 453, conduit 110 is connected to the first-stream intermediate header 454, conduit 206 is connected to the second-stream intermediate header 455, conduit 314 is connected to the third-stream outlet header 458, conduit 318 is connected to the sixth-stream inlet header 462, conduit 320 is connected to the sixth-stream intermediate header 463, and conduit 311 is connected to the fifth stream intermediate header 461. In another similar embodiment, the headers and internal passages associated with the fifth stream intermediate header at (iii) and the sixth-stream intermediate header of (iv) can be moved such that the outlets are closer or in close proximity to the headers (i), respectfully illustrated in FIG. 2 as heat transfer conduits 480, 481 and 482 and header locations 467, 468 and 469. In a similar manner, the first-stream and second-stream intermediate headers of (iv) and associated passages can be moved so as to be in closer proximity to the headers of (ii), respectfully illustrated as heat transfer conduits 478 and 479 and header locations 465 and 466. These latter embodiments are illustrated in FIG. 2 via dashed format.
In the second cooling cycle in the preferred embodiment depicted in FIG. 1, the natural gas stream, that being a normally gaseous material, is condensed. The refrigerant stream employed in this cycle is preferably ethylene. As noted in FIG. 1, a low stage recycle stream delivered via conduit 232 is compressed and the resulting compressed low-stage recycle stream is preferably removed from compressor 40 via conduit 234, cooled via inter-stage cooler 71, returned to the compressor via conduit 236 and combined with a high-stage recycle stream delivered via conduit 216 whereupon the combined stream is compressed thereby producing a compressed refrigerant stream via conduit 200. A preferred pressure for the compressed refrigerant stream is approximately 300 psia. Preferably, the two compressor stages are a single module although they may each be a separate module and the modules mechanically coupled to a common driver. The compressed ethylene, also referred to in this cycle as compressed refrigerant stream is routed from the compressor to the downstream cooler 72 via conduit 200. The product from the cooler flows via conduit 202 and is introduced, as previously discussed, to the first cycle wherein said stream is further cooled, liquefied and returned via conduit 208. This stream preferably flows to a separation vessel 41 which provides for the removal of residual light components from the liquefied stream and which also provides surge volume for the refrigeration system. Such vessels may be comprised of a single-stage gas-liquid separator or may be more sophisticated and comprised of an accumulator section, a condenser section and an absorber section, the latter two of which may be continuously operated or periodically brought on-line for removing residual light components from the refrigerant. A refrigerant stream, referred to herein with regard to the second cycle as a first refrigerant stream, is produced from vessel 41 via conduit 209.
The cooled natural gas stream (a normally gaseous material) produced via conduit 112 is combined with a yet to be described methane-rich stream provided via conduit 156. This combined stream via conduit 114 and the first refrigerant stream via conduit 209 are routed to the first brazed aluminum plate fin heat exchange section 42 in this cycle wherein these streams flow through core passages 44 and 46 countercurrent, more preferably counterflow, to and in indirect heat exchange with a yet to be described high-stage refrigeration stream and optionally, a low-stage refrigeration stream respectively flowing in passages 48 and 50. A cooled stream referred to herein as second refrigerant stream is produced from passage 46 via conduit 210. This stream is then split via a splitting or separation means (illustrated but not numbered) into two portions, third and fourth refrigerant streams, and produced via conduits 212 and 218. The third refrigerant stream via conduit 212 flows to a pressure reduction means, illustrated as expansion valve 52, wherein the pressure of the liquefied ethylene is reduced thereby evaporating or flashing a portion thereof thereby producing a high stage refrigeration stream. This stream then flows through conduit 214 and through core passage 48 thereby producing a high stage recycle stream which is transported via conduit 216 to the high stage inlet port of compressor 40.
Produced from passage 44 via conduit 116 is a further cooled natural gas stream which is optionally combined with a methane-rich recycle stream delivered via conduit 158. The resulting stream routed via conduit 120 to core 59 in core-in-kettle heat exchanger 58 wherein the stream is liquefied in major portion and the resulting stream produced via conduit 122.
The fourth refrigerant stream is transported via conduit 218 to passage 54 in second brazed aluminum plate fin heat exchange section 53. The fourth refrigerant stream flows countercurrent, more preferably counterflow, to and is in indirect heat exchange with a low stage refrigeration fluid flowing via passage 55 in heat exchange section 53 thereby producing a fifth refrigerant stream via conduit 220. The fifth refrigerant stream via conduit 220 flows through a pressure reduction means, illustrated as expansion valve 56, wherein the pressure of the liquefied ethylene is reduced thereby evaporating or flashing a portion thereof thereby producing a two-phase refrigerant stream. As previously noted, the pressure reduction step can take place via a valve with conduit (illustrated as 226) connecting the valve to the core-in-kettle heat exchanger or upon entrance to the core-in-kettle heat exchanger. The resulting two-phase refrigerant stream is then employed as a cooling agent on the kettle-side of core-in-kettle heat exchanger 58 wherein the stream is partitioned into gas and liquid portions and said cores are at least partially submerged in the liquid portion. Removed from the kettle-side of said exchange via conduit 228 is a low stage refrigeration stream. This conduit is connected to passage 55 in heat exchanger section 53 wherein said stream flows countercurrent and is in indirect heat exchange with the fluid in passage 54 thereby producing a low stage recycle stream. This stream is returned to the low stage inlet port at compressor 40 via conduit 232. Optionally, and as depicted in FIG. 1 this stream may also flow to the first plate fin heat exchanger in the cycle, 42, via conduit 230 and through passage 50 wherein said stream flows countercurrent, more preferably counterflow, to the fluids in passages 44 and 46 and is further warmed prior to flow to the compressor via conduit 232. Because of concern with the exposure of certain compressor components to cryrogenic conditions, this latter approach is preferred.
In one embodiment of the invention, brazed aluminum plate fin heat exchange sections 42 and 53 which are situated in the second cycle are separate heat exchangers. In another embodiment, the heat exchange sections are combined into a single exchanger. Although resulting in a more complex heat exchanger which possesses intermediate headers, this approach offers advantages from a lay-out and cost perspective. The following embodiment wherein the heat exchanger sections are combined into a single heat exchange section is a preferred embodiment. With regard to nomenclature in the ensuing discussion, reference will be made to first-stream, second-stream, third-stream, and fourth-stream elements, for example a first-stream intermediate header. In this context, reference is being made to a given element, that being an intermediate header to which is directed at least a portion of a given flow stream, that being the first-stream. Therefore, a second-stream inlet header, second-stream intermediate header and second-stream outlet header refer to headers which are connected to a common flow passage in a plate fin heat exchanger through which the second stream may flow.
A preferred embodiment which is illustrated in FIG. 3, a brazed aluminum plate fin heat exchanger 490 is employed which is comprised of (i) first-stream and second-stream inlet headers, 401 and 402, and third-stream and fourth-stream outlet headers, 403 and 404, located in close proximity to one another near one end of the plate fin heat exchanger; (ii) a second-stream outlet header 408 and a fourth-stream inlet header 409 located in close proximity to one another at the end opposing that set forth in (i); (iii) first-stream intermediate header 405, a second-stream intermediate header 406, and third-stream intermediate header 407 where said headers are situated between the headers of (i) and (ii) on said plant fin heat exchanger; (iv) a core within the plate fin heat exchanger comprised of at least one heat exchange conduit or passage 420 connecting the first-stream inlet header 401 and the first-stream intermediate header 405, at least one heat exchange conduit 421 connected the second-stream inlet header 402 to the second-stream intermediate header 406 and at least one heat exchange conduit 422 connecting the second-stream intermediate header 406 to the second-stream outlet header 408, at least one heat exchange conduit 423 connecting the third-stream intermediate header 407 to the third-stream outlet header 403, and at least one heat exchange conduit 424 connecting the fourth-stream inlet header 409 to the fourth-stream outlet header 404. Pressure reduction means 52 is respectively connected via conduit 212 to the second stream intermediate header 406 and via conduit 214 to the third-stream intermediate header 407. In this embodiment, conduit 114 is connected to the first-stream inlet header 401, conduit 116 is connected to the first-stream intermediate header 405, conduit 209 is connected to the second-stream inlet header 402, conduit 220 is connected to the second-stream outlet header 408, conduit 216 is connected to the third-stream outlet header 403, conduit 228 is connected to the fourth-stream inlet header 409 and conduit 232 is connected to the fourth-stream outlet header 404. In an optional configuration, the first-stream intermediate header 405 and associated flow passages are arranged so as to position said header in closer proximity to the headers of (ii). This is illustrated in FIG. 3 in dashed format via the addition of flow passage 426 to flow passage 420 and the substitution of first stream outlet header 410 for first stream intermediate header 405. In another embodiment, heat exchange conduit 424 is shorted, illustrated as conduit 425, and fourth-stream outlet header 404 is replaced by a fourth-stream intermediate header 411. These configurations are illustrated in FIG. 3 via dashed format.
The gas in conduit 154, that being a compressed recycled methane refrigerant stream, is fed to main methane economizer 74 which will be described in greater detail wherein the stream is cooled via indirect heat exchange means. In one embodiment and as illustrated in FIG. 1, the stream is delivered via conduit 154 is cooled in the main methane economizer 74 via indirect heat exchange means 97, a portion removed via conduit 156 and the remaining stream further cooled via indirect heat exchange means 98 and produced via conduit 158. This is a preferred embodiment. In this split stream embodiment, a portion of the compressed methane recycle stream delivered via conduit 156 is combined with the natural gas stream via conduit 112 immediately upstream of the second cycle and the remaining portion delivered via conduit 158 combined with the stream in conduit 116 immediately upstream of the core-in-kettle heat exchanger 58 wherein the majority of liquefaction of the natural gas stream occurs. In a simpler embodiment (i.e., less preferred from a process efficiency perspective), the methane recycle stream is cooled in its entirety in the main methane economizer 74 and combined via conduit 158 with the natural gas stream in conduit 112 immediately upstream of the second cycle.
The liquefied stream produced from the core-in-kettle heat exchanger via conduit 122 is generally at a temperature of about -125° F. and a pressure of about 600 psi. This stream passes via conduit 122 to the main methane economizer 74, wherein the stream is further cooled by indirect heat exchange means 76 as hereinafter explained. From the main methane economizer 74 the liquefied gas passes through conduit 124 and its pressure is reduced by a pressure reduction means which is illustrated as expansion valve 78, which of course evaporates or flashes a portion of the gas stream. The flashed stream is then passed to methane high-stage flash drum 80 where it is separated into a gas phase discharged through conduit 126 and a liquid phase discharged through conduit 130. The gas-phase is then transferred to the main methane economizer via conduit 126 wherein the vapor functions as a coolant via indirect heat transfer means 82. The vapor exits the main methane economizer via conduit 128 which is connected to the high-stage pressure inlet port on the compressor 83 from which is produced a compressed methane stream which is routed via conduit 150 to a cooler 86 where said stream is cooled and produced via conduit 152.
The liquid phase produced via conduit 130 is passed through a second methane economizer 87 wherein the liquid is further cooled by downstream flash vapors via indirect heat exchange means 88, preferably arranged to provide for countercurrent flow of the liquid stream relative to the downstream vapor streams. The cooled liquid exits the second methane economizer 87 via conduit 132 and is expanded or flashed via pressure reduction means illustrated as expansion valve 91 to further reduce the pressure and at the same time, vaporize a second portion thereof. This flash stream is then passed to intermediate-stage methane flash drum 92 where the stream is separated into a gas phase passing through conduit 136 and a liquid phase passing through conduit 134. The gas phase flows through conduit 136 to the second methane economizer 87 wherein the vapor cools the liquid introduced to 87 via conduit 130 via indirect heat exchanger means 89. Conduit 138 serves as a flow conduit between indirect heat exchange means 89 in the second methane economizer 87 and the indirect heat transfer means 95 in the main methane economizer 74. This vapor leaves the main methane economizer 74 via conduit 140 which is connected to the intermediate stage inlet on the methane compressor 83.
The liquid phase exiting the intermediate stage flash drum 92 via conduit 134 is further reduced in pressure by passage through a pressure reduction means illustrated as a expansion valve 93. Again, a third portion of the liquefied gas is evaporated or flashed. The fluids from the expansion valve 93 are passed to final or low stage flash drum 94. In flash drum 94, a vapor phase is separated and passed through conduit 144 to the second methane economizer 87 wherein the vapor functions as a coolant via indirect heat exchange means 90, exits the second methane economizer via conduit 146 which is connected to the first methane economizer 74 wherein the vapor functions as a coolant via indirect heat exchange means 96 and ultimately leaves the first methane economizer via conduit 148 which is connected to the low-stage inlet port on compressor 83. Preferably and as illustrated in FIG. 1, the vapor streams in indirect heat exchange means 82, 95 and 96 in the main methane economizer 74 flow countercurrent to the liquid stream in indirect heat exchange means 76 and the vapor streams in indirect heat exchange means 97 and 98.
The liquefied natural gas product from flash drum 94 which is at approximately atmospheric pressure is passed through conduit 142 to the storage unit. The low pressure, low temperature LNG boil-off vapor stream from the storage unit and optionally, the vapor returned from the cooling of the rundown lines associated with the LNG loading system, is preferably recovered by combining such stream or streams with the low pressure flash vapors present in either conduits 144, 146, or 148; the selected conduit being based on an attempt to match the temperature of the vapor stream as closely as possible.
As shown in FIG. 1, the three stages of compression provided by compressor 83 are preferably contained in a single unit. However, each compression stage may exist as a separate unit where the units are mechanically coupled together to be driven by a single driver. The compressed gas from the low-stage section preferably passes through an inter-stage cooler 85 and is combined with the intermediate pressure gas in conduit 140 prior to the second-stage of compression. The compressed gas from the intermediate stage of compressor 83 is preferably passed through an inter-stage cooler 84 and is combined with the high pressure gas in conduit 140 prior to the third-stage of compression. The compressed gas is discharged from the high-stage methane compressor through conduit 150, is cooled in cooler 86 and is routed to the high pressure propane chiller via conduit 152 as previously discussed.
FIG. 1 depicts the expansion of the liquefied phase using expansion valves with subsequent separation of gas and liquid portions in the chiller or condenser. While this simplified scheme is workable and utilized in some cases, it is often more efficient and effective to carry out partial evaporation and separation steps in separate equipment, for example, an expansion valve and separate flash drum might be employed prior to the flow of either the separated vapor or liquid to a chiller. In a like manner, certain process streams undergoing expansion are ideal candidates for employment of a hydraulic or gas expander as the case may be, as part of the pressure reduction means thereby enabling the extraction of work energy and also lower two-phase temperatures.
With regard to the compressor/driver units employed in the process, FIG. 1 depicts individual compressor/driver units (i.e., a single compression train) for the propane, ethylene and open-cycle methane compression stages. However in a preferred embodiment for any cascaded process, process reliability can be improved significantly by employing a multiple compression train comprising two or more compressor/driver combinations in parallel in lieu of the depicted single compressor/driver units. In the event that a compressor/driver unit becomes unavailable, the process can still be operated at a reduced capacity.
While specific cryogenic methods, materials, items of equipment and control instruments are referred to herein, it is to be understood that such specific recitals are not to be considered limiting but are included by way of illustration and to set forth the best mode in accordance with the present invention.
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The inventive process and associated apparatus are ideally suited for the small-scale liquefaction of natural gas. The current invention provides a methodology and apparatus for the liquefaction of normally gaseous material, most notably natural gas, which reduces both the number of process vessels required and also the associated space requirements over convention apparatus while resulting in only a slight decrease in process efficiency.
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BACKGROUND OF THE INVENTION
This invention relates to landing gear for trailers and more particularly relates to the structure of a landing gear sand shoe.
Landing gear for trailers are often subjected to sudden vertical shock forces and to horizontal load forces. A vertical shock force typically occurs when a trailer is uncoupled from a tractor and the forward end of the trailer is dropped to the ground upon its landing gear. Horizontal loads upon the landing gear occur when a tractor pushes against the trailer during coupling. The horizontal coupling forces tend to move the landing gear legs horizontally relative to the sand shoes possibly damaging the shoes or even shearing the shoes from the legs. One solution to this problem is provided by Dalton, U.S. Pat. No. 3,666,290 which teaches a rubber toroid disposed between the base of a round strut and a horizontally disposed foot plate, the toroid being encircled by a skirt congruently fit to the strut to prevent horizontal forces from shearing the toroid.
However, vertically retractable landing gear pose a problem not solved by Dalton. In such landing gear, the legs extend part way to the ground in the retracted condition, and the sand shoes often strike objects over which the trailer passes. It is thus advantageous to have sand shoes whose bottom surfaces are, upon landing gear retraction, tilted upward at the front edge rather than horizontally disposed as taught by Dalton. It has been found that an upwardly tilted sand shoe is less likely to snag upon objects passing beneath the trailer when the trailer is moved forward and that the tilted bottom surface of a landing gear shoe will often deflect objects striking the foot plate from a forward direction.
SUMMARY OF THE INVENTION
My invention comprises a tiltable landing gear sand shoe joined to the bottom of a landing gear leg. Within the shoe and compressed between the base plate of the leg and the ground engaging skid tray of the shoe is a wedge-like shock absorbing cushion biasing the skid tray toward the desirable tilted position in which the leading edge of the tray is higher than the trailing edge of the tray.
A further advantageous feature of my sand shoe is a means to quickly attach the shoe to, or release the shoe from, the landing gear leg. In this way damaged shoes can be quickly replaced with minimal inconvenience and labor costs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a trailer having my improved sand shoe.
FIG. 2 is an enlarged perspective view taken along line 2--2 in FIG. 1 of the landing gear sand shoe.
FIG. 3 is an exploded perspective view of the sand shoe shown in FIGS. 1 and 2.
FIG. 4 is a plan view of the elastomeric cushion housed by the landing gear shoe.
FIG. 5 is a side elevational view of the cushion shown in FIG. 4.
FIG. 6 is an end elevational view of the cushion shown in FIG. 4.
FIG. 7 is a cross-sectional view of the landing gear leg and shoe taken along line 7--7 of FIG. 2 showing the shoe and cushion in an unloaded condition.
FIG. 8 is a cross-sectional view of the landing gear leg and shoe similar to that in FIG. 7 showing the shoe and cushion in the loaded condition.
DETAILED DESCRIPTION
In FIG. 1 is shown a typical trailer 10 having a landing gear assembly 12 including legs 14 at the base of which sand shoes 16 are attached. Landing gear assembly 12 is typically a telescoping landing gear wherein leg 14 translates vertically into and from sheath 18 affixed to the bottom of trailer 10.
Referring now to FIGS. 2 and 3, leg 14 is typically a cross-sectionally square steel tube. At the base of leg 14 is welded a flat plate 20 generally perpendicular to the longitudinal axis of leg 14. Plate 20 overlaps the cross-section of leg 14 so that the edges of plate 20 extend away from leg 14 on all four sides. Preferably the corners of plate 20 are beveled and the periphery of plate 20 is smoothed so that plate 20 has no sharp edges or points to puncture or cut elastomeric cushion 22 against which plate 20 bears.
Forming an articulate joint with leg 14 and plate 20 is shoe 16 which includes a restriction collar comprising U-shaped section 24a and closure member 24b attached to ground engaging skid tray 26. U-shaped section 24a of the restriction collar preferably welded at the bottom of its three walls to skid tray 26 but closure section 24b is not affixed to skid tray 26 so that closure member 24b can be unbolted and removed from the shoe 16 to permit removal of sand shoe 16 from leg 14.
As can be seen in conjunction with FIGS. 2, 7 and 8, the four sides of restriction collar comprise walls 32 having flanges 34 extending inwardly from wall 32 toward leg 14 to form a square opening smaller in width than plate 20 and larger in width than leg 14. Flanges 34 lie above the peripheral edges of plate 20 so that plate 20 prevents the collar and thus sand shoe 16, from falling off leg 14. The peripheral gap 42 between exterior girth of leg 14 and the inner edges of flanges 34 allow the shoe to be tilted between 5 and 15 degrees and preferably 10 degrees in any direction with respect to plate 20 before one of flanges 34 abuts the side of leg 14. Thus, when landing gear assembly 12 rests upon the ground, shoes 16 tilt to adapt themselves to uneven or slanted ground surfaces. The width of peripheral gap 42 is dimensioned so as to allow the desired amount of shoe tiltability.
As seen in FIGS. 3, 7 and 8, a shock absorbing elastomeric cushion 22 is positioned between plate 20 and skid tray 26. Cushion 22 may have a Shore A durometer reading of between 55 and 65 and is preferably 60. It has been found that cushions having durometers between 55 and 65 Shore A provide the most desirable shock absorption qualities to reduce the effects of sudden vertical impacts on the landing gear assembly 12. As seen in FIGS. 4 and 5, elastomeric cushion 22 has a generally octagonal shape and has a longitudinal cross-section in the form of a truncated wedge. Conveniently positioned on the top of elastomeric cushion 20 are four feet 36. The purpose of feet 36 is to facilitate installation of shoes 16 onto leg 14. Before installation of shoe 16 onto leg 14, the U-shaped collar section 24a is welded onto skid tray 26 of shoe 16. Cushion 22 is then placed feet up on skid tray 26 within U-shaped portion 24a. Shoe 16 is then slid onto leg 14, the flanges 34 on the arms of U-shaped collar section 24a riding upon opposite edges of plate 20. While shoe 16 is sliding onto leg 14, upward pressure is maintained on shoe 16 to compress cushion 22 so that cushion 22 will fit between skid tray 26 and plate 20. Feet 36 take up the compression of cushion 22 as shoe 16 slides onto leg 14. Since feet 36 have a much smaller cross-sectional area and consequent smaller resistance to compression than does the bulk of cushion 22, less upward force upon shoe 16 is required to slide shoe 16 onto leg 14 than if feet 36 were not present. In addition, feet 36 provide a smaller frictional engagement surface bearing against plate 20 as shoe 16 is slid onto leg 14 than would plate engaging face 46 of cushion 22 if feet 36 were not present. Thus feet 36 reduce the frictional resistance between cushion 22 and plate 20 as shoe 16 slides onto leg 14. Although the structure of feet 36 is preferred, it should be recognized that the function of feet 36 could be accomplished by any suitable projections from plate engaging face 46 of cushion 22 having a small cross-sectional area as compared to the bulk of cushion 22 lying between plate engaging face 46 and tray engaging face 48.
When elastomeric cushion 22 is not under compressive load from trailer 10 as shown in FIG. 8, elastomeric cushion 22 is under a relatively slight compressive pre-load between plate 20 and skid tray 26 such that feet 36 are deformed. As shown in FIG. 7, cushion 22 in a pre-load condition resiliently bears against plate 20 and skid tray 26 so that skid tray 20 is held at an acute angle with respect to a horizontal plane. The rear edge of skid tray 26 is beneath the thicker end of elastomeric cushion 22 and is tilted downward while the front edge of skid tray 26 is beneath the thinner end of elastomeric cushion 22 and is tilted upward.
Elastomeric cushion 22 has features to increase its spring rate or resistance to compression as the compressive load transmitted to cushion 22 from trailer 10 increases. First, cushion 22 has a wedge shaped or inclined-plane shaped longitudinal cross-section and is also tapered about its periphery from top to bottom. The shape of cushion 22 thereby causes an increasingly greater cross-section of cushion 22 to resist compression of cushion 22 as the vertical load upon cushion 22 increases until cushion 22 reaches the fully compressed state shown in FIG. 8. Second, alternate octagon faces 38a, 38c, 38e and 38f face respective wall segments 32 of U-shaped section 24a and closure section 24b of the restriction collar. When cushion 22 expands horizontally under compressive loading transferred through plate 20, octagon faces 38a, 38c, 38e and 38f contact wall segments 32 and receive lateral support from therefrom. As cushion 22 is further compressed and expands further horizontally, increasing surface areas of octagon faces 38a, 38c, 38e and 32f contact the respective walls 32 and thus receive increasing lateral support from the walls so that cushion 22 has increased spring rate to resist compression as compressive forces increase in magnitude.
It should be noted that not all expansion of cushion 22 under load is restricted. Aperture 40 in elastomeric cushion 22 centered with respect to octagon sides 38a through 38h permits horizontal expansion of a portion of cushion 22. In addition, octagon faces 38b, 38d, 38f and 38h do not parallel the opposing walls of the restriction collar and thereby are permitted to expand into the corners of the restriction collar. If cushion 22 were not permitted to expand horizontally as it is compressed vertically, cushion 22 would lose elasticity and would have an excessive spring rate. Thus the aperture 40 and the empty corners of the restriction collar prevent cushion 22 from stiffening to an undesirably high spring rate by providing a volume into which cushion 22 can expand when cushion 22 is compressed. While cushion 22 is shown in the preferred configuration herein, it will be recognized that cushion 22 may be modified in shape so long as sufficient volume in shoe 16 is provided to permit lateral expansion of cushion 22 when cushion 22 is compressed.
It should be further noted that deformation of elastomeric cushion 22 due to shear forces acting upon cushion 22 is limited by restriction collar of shoe 16. Horizontal forces acting on leg 14 or shoe 16 during, for example, coupling of trailer 10 to a tractor unit (not shown) can cause relative lateral movement between shoe 16 and leg 14 and thus cause a shear stressing of elastomeric cushion 22. However, the aforesaid horizontal forces can only cause relative lateral movement between leg 14 and shoe 16 until one of flanges 34 of shoe 16 abuts with one side of leg 14. At this point a flange 34 of shoe 16 resists further relative lateral movement between shoe 16 and leg 14, thereby preventing further shear stressing of cushion 22.
While the above description presents the preferred embodiment of my invention, it is recognized that a number of modifications to my invention may occur to those skilled in the relevant art which may fall within the scope of the following claims.
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Disclosed herein is a landing gear assembly having legs extending downward from the underframe of a trailer and having a sand shoe at the ground engaging end thereof. The shoe is articulately joined to the ground engaging end of the leg by a collar circumscribing the ground engaging end of the leg. Compressed between the base of the leg and the bottom of the shoe is a wedge-shaped resilient member biasing the shoe into a tilted position relative to the plate.
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FIELD
This disclosure relates to apparatus and methods of stably supporting self-propelled derrick rigs such as workover rigs, drilling rigs, cranes and the like, using a portable base beam.
BACKGROUND
A completion or workover rig is used to do repair work on a well, such as tubing or pump replacement. When a workover rig is used to do repair work on a well, the rig must be able to pull weights near the rated capacity of the derrick of the rig, withstand high wind gusts, and otherwise be stably supported. Further, a workover rig should operate to its design capacity on a high frequency basis, and be highly mobile and self-contained.
A trend in workover rigs to maintain mobility and higher load capacities has been to use guy wires to stabilize the rig. The use of guys can significantly increase the rated capacity of the rig without changing the basic design.
However, there are drawbacks to a guy system. For example, guy wires need to be in specific locations for the stability and safe operation of the rig, and setup time is longer with a guy setup due to the specific locations. In addition, workover rigs typically tie off to permanent anchors set in the ground in a rectangular pattern around the well head. However, with the growing utilization of multi-well pads, it is nearly impossible to guy the workover rig to the anchors that were originally set in the ground when the well was drilled.
Solutions have been sought to solve the problem of a workover rig not being able to be supported by permanent anchors. One solution has been to utilize one or more base beams that are heavy, portable structures placed on the ground and to which the workover rig is guyed. Existing base beams have a relatively small footprint as well as set locations with which to attach guy wires, which makes set-up easier and faster.
SUMMARY
Improvements to base beams and self-propelled derrick rigs are described. A self-propelled derrick rig as used herein is intended to encompass any type of self-propelled vehicle that has a derrick structure mounted on it which can be moved to a raised position during use, a driver's cab and an engine for propelling the vehicle. Examples of self-propelled derrick rigs include, but are not limited to, workover rigs, drilling rigs, cranes and the like.
When the self-propelled derrick rig is mounted to the base beam, the assembly will be able to withstand high hook loads and wind loading without the danger of the rig coming off of its wheels or falling over. The self-propelled derrick rig can be easily and quickly mounted to the base beam. The assembly also allows support equipment, for example a portable pipe handling machine in the case of a workover rig, to work alongside it. In addition, the base beam can be transported as a single load on a vehicle, for example on a flatbed truck.
The base beam includes stabilizer arms that are attached, for example pivotally attached, to the base beam to help stabilize the base beam and the rig itself. A height adjustable stabilizer pad can be connected to each stabilizer arm to help level the stabilizer arms and the base beam on the ground.
In addition, to the base beam, a unique counterweight assembly is described that in use is connected to the front of the rig to help stabilize the rig and prevent the front of the rig from coming off of the ground.
In one embodiment, a base beam that is used to support a self-propelled derrick rig includes a longitudinally extending metal main beam having first and second opposite ends, a front side, a back side, a top and a bottom, where the bottom is substantially planar. The main beam includes a central section approximately midway between the first and second ends thereof on which the derrick structure of the rig will be supported. The central section can reinforced between the top and the bottom, and the top of the central section is substantially planar. First and second stabilizer arms are attached, for example pivotally attached or non-pivotally attached, to the main beam when pivotally attached, the stabilizer arms are pivotable relative to the main beam between a refracted or transport position where the first and second stabilizer arms are generally parallel to the main beam and a fully extended or deployed position where the first and second stabilizer arms are not parallel to the main beam. In addition, at least one guy attachment point is provided on each of the first and second stabilizer arms to allow guys to attach between the derrick structure and the stabilizer arms.
In another embodiment, there can be a plurality of guy attachment points on the main beam.
In another embodiment, additional stabilizer arms can be provided on the main beam to provide even more stabilization.
In still another embodiment, an assembly is provided that includes a base beam and a self-propelled derrick rig. The base beam can include a longitudinally extending metal main beam having first and second opposite ends, a front side, a back side, a top and a bottom, and a central section. First and second stabilizer arms can be attached, for example pivotally attached or non-pivotally attached, to the main beam. When pivotally attached, the stabilizer arms are pivotable relative to the main beam between a retracted position where the first and second stabilizer arms are generally parallel to the main beam and a fully extended position where the first and second stabilizer arms are not parallel to the main beam. The self-propelled derrick rig can include a derrick structure adjacent a first end of the rig that is disposed in a raised position, a driver's cab, and an engine that provides power for propelling the rig. A base of the derrick structure can be supported on the central section of the main beam on the top thereof. In addition, a plurality of guys extend between the derrick structure and the rig, and a plurality of guys extend between the derrick structure and the base beam.
In yet another embodiment, the counterweight assembly includes a sled that has a mechanism to connect the sled to the self-propelled derrick rig. The connection can be the sled simply resting on the front of the rig to weigh down the front end, or the sled can be removably attached to the rig. A plurality of weights are removably disposed on the sled. Each weight is individually separable from the other weights and each weight is individually removable from the sled.
In another embodiment, a method of supporting a derrick structure of a self-propelled derrick rig is provided, where the derrick structure is disposed adjacent to a first end of the rig and is movable between a raised position and a lowered position. In the method, a base beam is arranged on the ground, and stabilizer arms that are pivotally or non-pivotally connected to the base beam are deployed from a retracted position to a fully deployed position. The self-propelled derrick rig is arranged adjacent to the base beam, and the derrick structure of the self-propelled derrick rig is raised to the raised position. A base end of the derrick structure is attached to the base beam. In addition, a plurality of guys are attached between the derrick structure and the remainder of the rig and a plurality of guys are attached between the derrick structure and the base beam.
In another embodiment of a method, a base beam is arranged on the ground, and the self-propelled derrick rig is arranged adjacent to the base beam. The derrick structure of the self-propelled derrick rig is raised to the raised position, and a base end of the derrick structure is attached to the base beam. A plurality of guys are attached between the derrick structure and the remainder of the rig and a plurality of guys are attached between the derrick structure and the base beam. A counterweight assembly is also connected to the rig at a second end thereof opposite the first end and the derrick structure to weigh down the front of the rig.
DRAWINGS
FIG. 1 illustrates an assembly including an exemplary self-propelled derrick rig mounted to an exemplary base beam.
FIG. 2 is a perspective view of the base beam in a folded condition.
FIG. 3 is a perspective view of the base beam with the stabilizer arms extended.
FIG. 4 is a perspective view of the derrick rig and the base beam at a point during assembly.
FIG. 5 is a close up view detailing an exemplary technique for fixing the derrick of the rig to the base beam.
FIG. 6 is a perspective view of the front of the derrick rig showing a counterweight assembly in place.
FIG. 7 is a detailed view of the counterweight assembly of FIG. 6 .
FIG. 8 is a side view of the counterweight assembly of FIG. 6 .
FIG. 9 illustrates the counterweight assembly disposed on top of the base beam during transport.
FIG. 10 illustrates an alternative embodiment of a base beam.
FIG. 11 illustrates another alternative embodiment of a base beam.
FIGS. 12A and 12B illustrate still another alternative embodiment of a base beam in extended and folded conditions, respectively.
FIG. 13 illustrates another alternative embodiment of an assembly of a self-propelled derrick rig and a base beam.
FIG. 14 illustrates still another alternative embodiment of an assembly of a derrick rig and a base beam.
FIG. 15 illustrates still another alternative embodiment of an assembly of a derrick rig and a base beam.
FIG. 16 illustrates an exemplary attachment between the counterweight assembly and the rig.
DETAILED DESCRIPTION
As described in further detail below, an improved base beam is described that is used to support a self-propelled derrick rig. A self-propelled derrick rig as used herein is intended to encompass any type of self-propelled vehicle that has a derrick structure mounted on it which can be moved to a raised position during use, a driver's cab and an engine for propelling the vehicle. Examples of self-propelled derrick rigs include, but are not limited to, workover rigs, drilling rigs, cranes and the like. The self-propelled derrick rig will be described below as, and is illustrated in the drawings as, a workover rig. However, the derrick rig can be any other type of rig that can benefit from being supported using a base beam(s) as described herein.
With reference initially to FIG. 1 , an assembly 10 is illustrated that includes a base beam 12 that is shown together with a self-propelled derrick rig 14 in the form of a workover rig. The base beam 12 is disposed adjacent to a well head 16 , with the rig 14 being used to perform a service function on the well.
The rig 14 includes a derrick structure 18 disposed adjacent to a first or rear end of the rig, where the derrick structure includes a raised position (shown in FIG. 1 ) and a lowered position (shown in FIG. 4 ). The rig 14 also includes a platform 20 , a driver's cab 22 disposed on the platform adjacent to a second or front end of the rig, wheels 24 mounted on the platform 20 , and an engine 26 adjacent to the front of the rig that provides power for propelling the rig during driving of the rig.
In the raised position of the derrick structure 18 shown in FIG. 1 , a base of the derrick structure 18 is supported on the base beam 12 . In addition, a plurality of guys 28 extend between the derrick structure 18 and different points on the remainder of the rig 14 , and a plurality of guys 30 extend between the derrick structure 18 and the base beam 12 .
With reference to FIGS. 2 and 3 , the base beam 12 includes a main beam 40 that extends along a longitudinal axis A-A from a first end 42 a to a second, opposite end 42 b . The main beam 40 further includes a front side 44 , a back side 46 , a top 48 and a bottom (not visible in FIGS. 2-3 ). The bottom is substantially planar to allow the main beam 40 to lay flat on the ground. In the illustrated example, the main beam 40 is generally rectangular in shape, although other shapes could be used.
The main beam 40 further includes a substantially planar central section 50 approximately midway between the first and second ends 42 a , 42 b thereof. As discussed further below with respect to FIGS. 4-5 , in use the central section 50 supports the base of the derrick structure 18 . Therefore, if considered necessary to support the derrick structure, the central section 50 of the main beam can be reinforced between the top 48 and the bottom, for example by employing internal reinforcing members disposed within the main beam 40 at the central section 50 .
Further, first and second swing or stabilizer arms 52 a , 52 b are pivotally attached to the main beam 40 . In the embodiment illustrated in FIGS. 2 and 3 , the swing arms 52 a , 52 b are pivotally attached to the main beam adjacent to the first and second ends 42 a , 42 b , respectively. The swing arms are pivotable relative to the main beam 40 between a retracted position (shown in FIG. 2 ) where the first and second swing arms are generally parallel to the main beam and a fully extended or deployed position (shown in FIG. 3 ) where the first and second swing arms are not parallel to the main beam.
In an alternative embodiment, the stabilizer arms can be initially separate from the main beam 40 and then attached to the main beam in the extended or deployed position for use. In this embodiment, the stabilizer arms need not be pivotally attached since the arms are attached for use and detached (or not detached) during transport.
In the illustrated embodiment, when fully deployed, the swing arms 52 a , 52 b extend from the front side 44 of the main beam and are disposed at generally right angles to the longitudinal axis A-A. As shown in FIG. 2 , each of the first and second swing arms has a length L, and the combined length of the first and second swing arms 52 a , 52 b can be less than the longitudinal length of the main beam to permit the swing arms to completely fold to the retracted position parallel to the axis A-A. However, as discussed further below, other configurations of the swing arms are possible.
Each swing arm 52 a , 52 b includes a first swing arm end 54 that is pivotally attached to the main beam, and a second swing arm end 56 . A stabilizer pad 58 is connected to the second swing arm end 56 of each swing arm. Each stabilizer pad 58 is adjustable in height to allow leveling of the swing arms and the base beam on uneven ground.
The base beam 12 is constructed primarily of a metal material such as steel. The main beam 40 between the top 48 and bottom is generally hollow. However, if additional weight for the base beam 12 is required, weights that are initially separate from the main beam can be disposed on the main beam adjacent to each of the ends 42 a , 42 b . In one embodiment, concrete can be poured into the hollow interior of the main beam adjacent to the ends 42 a , 42 b to increase the weight of the base beam. In another embodiment, removable weights can be placed on top of the main beam adjacent to the ends thereof. However, any technique for adding weight to the base beam 12 to increase the weight of the beam can be used.
The base beam 12 further includes a plurality of guy attachment points to permit attachment to the guys 30 . The guy attachment points can be provided at locations that one determines to be suitable for adequately guying the derrick structure 18 . In the embodiment illustrated in FIGS. 2 and 3 , there is at least one guy attachment point 60 on each of the first and second swing arms, for example adjacent to the second ends 56 . In addition, there can be a plurality of guy attachment points 62 on the main beam 40 , for example adjacent to the ends 42 a , 42 b . The guy attachment points 60 , 62 can be, for example, flanges that are attached to the base beam 12 and that include a hole to permit attachment of one end of the guys. The guys 30 (as well as the guys 28 ) can be wires or any structure suitable for use as guys.
Other configurations of the base beam are possible. For example, FIG. 10 illustrates a base beam 212 with a main beam 240 and a pair of swing arms 252 a , 252 b pivotally attached to the main beam 240 for pivoting movement between a retracted position (not shown) where the first and second swing arms are generally parallel to the main beam and a fully extended or deployed position (shown in FIG. 10 ) where the first and second swing arms are not parallel to the main beam. In this embodiment, the swing arms are pivotally attached to the main beam 240 so that the first and second arms 252 a , 252 b extend from a back side of the main beam when in the fully extended position in a direction generally toward the front end of the rig 14 and parallel to the rig.
FIG. 11 illustrates a base beam 312 with a main beam 340 and two pairs of swing arms 352 a , 352 b , 352 c , 352 d pivotally attached to the main beam 340 for pivoting movement between a retracted position (not shown) where the swing arms are generally parallel to the main beam and a fully extended or deployed position (shown in FIG. 11 ) where the swing arms are not parallel to the main beam. In this embodiment, the swing arms are pivotally attached to the main beam 340 so that the swing arms 352 a , 352 b extend from a front side of the main beam similar to FIGS. 2-3 , while the swings arms 352 c , 352 d extend from the back side of the main beam similar to FIG. 10 .
FIGS. 12A and 12B illustrate a base beam 412 with a main beam 440 and two pairs of swing arms 452 a , 452 b , 452 c , 452 d pivotally attached to the main beam 440 for pivoting movement between a retracted position (shown in FIG. 12B ) where the swing arms are generally parallel to the main beam and a fully extended or deployed position (shown in FIG. 12A ) where the swing arms are not parallel to the main beam. In this embodiment, the swing arms are pivotally attached to the main beam 440 so they extend from the front and back sides of the main beam similar to FIG. 11 . In addition, each of the swing arms 452 a , 452 b includes a first section 454 that is pivotally attached to the main beam and a second section 456 that is pivotally attached to the first section. Constructing the arms 452 a , 452 b with two sections allows the two sections 454 , 456 to fold together, for example one above the other as shown in FIG. 12B , which allows the length of the arms to be increased, while allowing the arm sections 454 , 456 to fold to the retracted position.
FIG. 14 illustrate a base beam 512 with a main beam 540 and a pair of swing arms 552 a , 552 b pivotally attached to the main beam 540 for pivoting movement between a retracted position (not shown) where the swing arms are generally parallel to the main beam and a fully extended or deployed position (shown in FIG. 14 ) where the swing arms are not parallel to the main beam. In this embodiment, the swing arms 552 a , 552 b are pivotally attached to the main beam 540 away from the ends of the beam 540 and more toward the center of the main beam. In addition, the swing arms do not extend at right angles to the main beam as in the other embodiments. Instead, the swing arms 552 a , 552 b are disposed at acute angles α relative to the longitudinal axis of the main beam.
Returning now to FIGS. 1-3 together with FIGS. 4-5 , in use, the base beam is transported to a position adjacent to the well head 16 and arranged on the ground. The swing arms are then deployed from the retracted position, which is used during transport of the base beam, to the fully deployed position. If necessary, the stabilizer pads 58 are adjusted in height to level the swing arms and the main beam. The self-propelled derrick rig 14 is then backed up to a position adjacent to the base beam as shown in FIG. 4 . During this time, the derrick structure 18 is likely at its lowered or transport position as shown in FIG. 4 , although in some circumstances the derrick structure could already be raised or partially raised. If the derrick structure is not raised, the derrick structure is raised to the raised position shown in FIG. 1 .
With reference to FIG. 5 , once the derrick structure 18 is raised, a base end 70 of the derrick structure is attached to the base beam 12 . In particular, one side of the base end 70 is pivotally connected to the rig platform 20 by pivots 72 . The other side of the base end is provided with a pair of height adjustable stabilizer pads 74 . Metal plates 76 are laid on the top 48 of the main beam at the central section 50 , and the pads 74 rest on the plates 74 . The base end 70 is fixed to the main beam by one or more fixation members 78 . In one embodiment, four fixation members 78 can be used, each of which attaches at one end to the base end 70 of the derrick structure 18 and attach at opposite ends thereof to mounting fixtures 80 that are disposed adjacent to the front side and the back side respectively of the main beam adjacent to, and on opposite sides of, the central section 50 . In the illustrated embodiment, the fixation members 78 comprise shackles, although any type of fixation members that can adequately attach the base end of the derrick structure to the main beam can be used.
In addition, as shown in FIG. 1 , the guys 28 are then attached between the derrick structure and the remainder of the rig, and the guys 30 are attached between the derrick structure and the base beam. FIG. 1 illustrates the derrick structure 18 as including a rig floor 82 and a tubing or racking board 84 both of which are conventional structures on workover rigs. The guys 28 are illustrated as generally extending from the top of the derrick structure to other points on the rig. Some of the guys 30 extend from the base beam to the top of the derrick structure, while some of the guys 30 extend from the base beam to the tubing board 84 and from the tubing board to the top of the derrick structure. However, the exact arrangement and number of the guys 28 , 30 can vary based on a number of factors, such as the expected loading conditions on the derrick structure and the rig. Therefore, the guy arrangement illustrated in FIG. 1 is exemplary only and can vary from the illustrated arrangement both in the number of guys 28 , 30 used and their locations.
Under some loading conditions, for example when the derrick structure is pulling at or near capacity, the front end of the rig 14 may want to come off the ground. To prevent such an occurrence, an optional counterweight assembly 90 can be used that is connected to the front end of the rig 14 to weigh down the front of the rig. The assembly 90 can simply connect to the front of the rig by resting on some portion of the front. Alternatively, the assembly 90 can be connected to the rig by removably attaching the assembly to the rig, for example by pinning or bolting the assembly to the rig. Any form of connection can be used as long as the assembly 90 increases the weight of the front of the rig.
With reference to FIGS. 6-8 , the counterweight assembly 90 can include a sled 92 that is designed to connect to the rig 14 and carry separate weights 94 that can be added and removed from the sled 92 to alter the amount of weight carried by the sled.
The sled 92 is a generally rectangular structure that includes a base 96 , reinforcing members 98 at each side end of the base, a front side 100 and a rear side 102 . The rear side 102 of the sled 92 includes a plurality of vertical beams 104 connected at base ends thereof to the base 96 and at upper ends thereof to a horizontal beam 106 . As best seen in FIG. 8 , the horizontal beam 106 and/or the beams 104 can be connected to a block, for example of wood, that rests on a ledge at the front of the rig. Thus, the assembly 90 weights down the front end of the rig.
If there is concern that the assembly could move, the assembly could be removably attached to the rig. For example, with reference to FIG. 16 , the attachment mechanism can comprise flanges 116 that are fixed to the beam 106 and/or the beams 104 , with corresponding flanges 118 on the front of the rig that align with the flanges on the sled. Pins or bolts 119 can then extend through holes in the aligned flanges to attach the sled to the rig.
Each weight 94 is individually separable from the other weights 94 and each weight is individually removable from the sled 92 . The weights 94 are generally rectangular in shape and resemble plates. The sled can be designed to hold any number of weights, based in part on how much counterweight one may need.
To aid in mounting, removal and transport of the sled 92 , at least two forklift pockets 110 are formed in the base 96 . The forklift pockets 110 permit a forklift to lift and transport the sled 92 . Similarly, each of the weights 94 includes at least two forklift pockets 112 formed therein. The forklift pockets 112 permit a forklift to lift and transport each of the individual weights 94 . Instead of forklift pockets, any structure that performs a function similar to the forklift pockets can be used.
The sled 92 further includes at least one guy attachment point 114 . For example, in the illustrated embodiment, the sled includes a plurality of the guy attachment points 114 , with the guy attachment points being located at the rear side 102 of the sled. As best seen in FIGS. 1 and 8 , two guys 28 extend from the derrick structure 18 to the attachment points 114 to guy the counterweight assembly to the derrick structure.
With reference to FIG. 9 , the shape of the sled 92 is such that the sled 92 together with any weights held thereon can be disposed on the base beam 12 during transport of the base beam and the counterweight assembly. This minimizes the space taken up during transport.
With reference to FIG. 13 , an embodiment is illustrated that uses two base beams. One base beam 120 is substantially similar to the base beam 12 . Alternatively, the base beam 120 could be similar to the base beams 212 , 312 , 412 , or 512 . A second base beam 122 is disposed underneath the rig 14 , for example underneath jacks or outriggers that are provided on the rig 14 . The construction and use of jacks or outriggers on rigs is well known in the art. In this embodiment, guys 124 extend from the derrick structure 18 and are connected to the ends of the second base beam 122 to help support the derrick structure.
FIG. 14 shows another embodiment that is similar to FIG. 13 , but using the base beam 512 together with the second base beam 122 .
FIG. 15 shows another embodiment that uses two base beams, including one base beam 130 that is substantially similar to the base beam 12 . In this embodiment, a second base beam 132 is disposed underneath the rig 14 at a location that is further forward than the second base beam 122 in FIG. 13 . For example, the second base beam 132 can be disposed underneath jacks disposed under the driver's cab 22 , and guys 134 extend from the derrick structure 18 and are connected to the ends of the base beam 132 to help support the derrick structure.
The second base beams 122 , 132 illustrated in FIGS. 13-15 are depicted as not including swing arms. However, the second base beams 122 , 132 could be configured to have swing arms similar to those discussed above.
The individual features of the various embodiments described herein can be used individually or in any combination with any other embodiment described herein.
The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
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Improvements to base beams and self-propelled derrick rigs are described. The base beam can have two or more stabilizer arms which can be deployed. The base beam is also designed to support the derrick rig. An optional counterweight assembly can be connected to the front of the rig. The self-propelled derrick rig can be easily and quickly mounted to the base beam, and when mounted, the assembly will be able to withstand high hook loads and wind loading without the danger of the rig coming off of its wheels or falling over.
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BACKGROUND
[0001] Lightweight steel-framed structures typically employ ribbed building panels to cover the roof and walls of the structure. Oftentimes, the building panels are constructed from metal, such as steel or aluminum. The building panels are formed to have a rib and valley profile to strengthen the building panels despite their thin construction.
[0002] Over time, due to natural deterioration or damage from various causes, the building panels on structures need to be replaced. However, the removal and replacement of the building panels consumes a great deal of labor and financial resources. Oftentimes, the best solution to the repair of a structure having deteriorating or damaged building panels is to simply retrofit the structure with new roof or wall panels by directly securing the new building panels to the existing building panels. In this manner, the labor and expense of removing the existing building panels can be saved.
[0003] One example of a system for retrofitting a structure with new building panels is taught by U.S. Pat. No. 5,367,848. The system is essentially provided with an elongated bracket having a Z-shaped cross-section. The bracket is designed to extend transversely across the existing building panels adjacent the location of a frame member. A series of notches are formed within the one generally vertical wall member of the Z-shaped bracket to allow the bracket to “nest” onto and over the ribbed profile of the existing building panel. A bottom wall portion extends outwardly from the bracket and is provided with apertures so that the user may secure the bracket to the existing building panel using a plurality of new fasteners. A top flange provides a mating surface for supporting the new building panel. A second series of new fasteners are used to secure the new building panel to the bracket. While the design of the bracket solved a number of problems existing in the art at the time it was introduced, it suffers from a number of deficiencies. First, the goal in retrofitting building panels is to reduce the overall labor and materials required to retrofit the new building panels onto the structure. The design of the Z-shaped bracket requires a full first course of fasteners to secure the bracket to the existing building panel. Then, a full second course of fasteners is required to secure the new building panel to the bracket. An additional deficiency with the bracket stems from its Z-shaped design. The bottom wall member is secured to the existing building panel alone. The new building panel is fastened only to the top wall member of the bracket. Accordingly, there is no direct structural connection between the new building panel and the frame member of the building. The strength of the connection between the new building panel and the building itself depends upon the strength of the bracket. Moreover, the Z shape provides only one vertically-oriented wall member, which provides a less than desirable level of stability when forces are exerted on the new building panels.
[0004] Another example of a system and method of retrofitting building panels is disclosed by U.S. Pat. No. 7,174,686, which is owned by the assignee of the present invention. That system is provided with a bracket having forward and rearward walls that are coupled to one another by a top wall, forming an open channel between the forward and rearward walls. In use, the bracket is disposed along the exterior surface of existing building panels such that a course of existing fasteners is disposed within the open channel of the bracket. One or more new building panels are then placed closely adjacent the top wall of the bracket and a single course of new fasteners is disposed through the new building panels, the bracket, the existing building panels, and a sub-frame of the building. This bracket design provides numerous improvements over other prior art brackets. However, the bracket design does not necessarily provide for accurate placement of the bracket, prior to the installation of the new building panels. An undesirable degree of lateral movement is permitted between the bracket and the course of existing fasteners in certain applications. Moreover, preferred methods of using this design of bracket do not always provide for optimal placement of the bracket to receive the final course of new fasteners that secure the new panels with the structure.
[0005] Accordingly, what is needed is a new system and method for retrofitting building panels to a structure that not only provides a convenient and accurate manner of retrofitting building panels but also decreases the labor and materials required to implement the system, while increasing the overall stability of the new building panels with respect to the structure.
SUMMARY
[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.
[0007] The bracket of the present invention is provided for use in retrofitting new building panels to a structure having existing building panels that are fastened to frame members. The bracket is generally provided with a first wall and a second wall that are coupled to one another at their upper end portions by a top wall. The interconnection between the first, second and top walls defines a channel that extends along the length of the bracket. The bottom end portions of the first and second walls are selectively shaped to mimic the rib and valley profile of the existing building panels, permitting the bracket to substantially engage its lower end portion with the upper surface of the existing building panel.
[0008] One or more base flanges may be provided to cantilever from the lower end portions of the first and/or second walls. In one embodiment, the at least one base flange may cantilever away from the bracket so that it may be used with a small number of fasteners to pre-install the bracket prior to installation of the new building panels. Another embodiment of the base flange may cantilever inwardly, toward a center portion of the bracket. The channel is shaped and sized to substantially enclose the existing fasteners, which couple the existing building panel to the frame member. Accordingly, a single elongated bracket may be positioned to enclose a course of existing fasteners across the existing building panel. The inwardly cantilevered base flange may be positioned adjacent the course of existing fasteners, preventing the bracket from sliding forward or rearward with respect to the existing building panel and properly positioning the bracket. A single course of new fasteners is then used to secure the new building panel to the bracket and the existing building panel. In a preferred embodiment, the fasteners will also engage the frame member.
[0009] It is therefore one of the principal objects of the present invention to provide a bracket for retrofitting new building panels to a structure with a minimal amount of materials and labor.
[0010] A further object of the present invention is to provide a bracket for retrofitting building panels to a structure that can be adapted for use with existing building panels having nearly any profile.
[0011] Yet another object of the present invention is to provide a bracket that reduces the typical number of steps required for retrofitting building panels to a structure.
[0012] A further object of the present invention is to provide a bracket that provides at least one base flange that helps locate the bracket in position before new panels are secured to the bracket and a building structure.
[0013] Still another object of the present invention is to provide a bracket for retrofitting new building panels to a structure that uses a base flange to temporarily secure the bracket to existing building panels, prior to placement of the new building panels.
[0014] Yet another object of the present invention is to provide a bracket for retrofitting new building panels to a structure that uses a base flange to engage existing fasteners on the structure to locate the bracket before its installation.
[0015] These and other objects of the present invention will be apparent after consideration of the Detailed Description and Figures herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
[0017] FIG. 1 is a perspective view of one embodiment of the bracket of the present invention as the same might be used to secure a new roof panel to an existing roof panel on a structure;
[0018] FIG. 2 is an isometric view of the embodiment of the bracket of FIG. 1 ;
[0019] FIG. 3 is a top view of the bracket depicted in FIG. 1 ;
[0020] FIG. 4 is a side elevation view of the bracket depicted in FIG. 1 ;
[0021] FIG. 5 is a cross-sectional view of the bracket depicted in FIG. 4 ;
[0022] FIG. 6 is a partial end elevation view depicting one manner in which the bracket depicted in FIGS. 1-5 could be used to secure a new roof panel to an existing roof panel on a structure;
[0023] FIG. 7 is an isometric view of a second embodiment of the bracket of the present invention;
[0024] FIG. 8 is a top view of the bracket depicted in FIG. 7 ;
[0025] FIG. 9 is a side elevation view of the bracket depicted in FIG. 8 ;
[0026] FIG. 10 is a cross-sectional view of the bracket depicted in FIG. 9 ;
[0027] FIG. 11 is a partial end elevation view depicting one manner in which the bracket depicted in FIG. 7 could be used to secure a new roof panel to an existing roof panel on a structure;
[0028] FIG. 12 is an isometric view of a third embodiment of the invention;
[0029] FIG. 13 is a top view of the embodiment of FIG. 12 ;
[0030] FIG. 14 is a side view of the embodiment of FIG. 12 ;
[0031] FIG. 15 is an end view of the embodiment of FIG. 12 ; and
[0032] FIG. 16 is a partial end elevation view depicting one manner in which the bracket of FIG. 12 may be used to secure a new roof panel to an existing panel on a structure.
DETAILED DESCRIPTION
[0033] Embodiments of the invention are described more fully below with reference to the accompanying figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense in that the scope of the present invention is defined only by the appended claims.
[0034] The bracket 10 of the present invention is generally depicted in FIGS. 1-16 in various embodiments. A first embodiment of the invention is shown in FIGS. 1-6 while a second embodiment of the invention is shown in FIGS. 7-11 and a third embodiment of the invention is shown in FIGS. 12-16 . Generally, the bracket 10 is provided with a first wall 12 , second wall 14 and a top wall 16 . The first wall 12 , second wall 14 and top wall 16 are coupled to one another so that they define a channel 18 that extends along the length of the bracket 10 . In a preferred embodiment, the lower end portions of the first wall 12 and the second wall 14 are shaped to have a profile that mimics a profile of the rib portions 20 and valley portions 22 of the existing building panels 24 , as depicted in FIG. 1 , so that the bracket 10 nests with the existing building panels 24 .
[0035] At least one base flange 26 may be coupled with the lower end portion of either or both of the first wall 12 and the second wall 14 . In one aspect, a first base flange 26 ′ may be provided to cantilever away from the first wall 12 and the second wall 14 , such as depicted in FIG. 2 . In another embodiment, the first base flange 26 ′ may be provided to cantilever away from the lower end portion of the first wall 12 toward the second wall 14 , as depicted in FIG. 7 . Another aspect of the invention provides for a second base flange 26 ″, which may be provided to cantilever from the lower end portion of the second wall 14 . While it is contemplated that the second base flange 26 ″ could be provided to extend away from both the first wall 12 and the second wall 14 , a preferred embodiment disposes the second base flange 26 ″ in a manner that cantilevers it away from the second wall 14 toward the first wall 12 . One or more embodiments may make it desirable to use both a first base flange 26 ′ and a second base flange 26 ″. However, it is contemplated that only one of a first base flange 26 ′ or a second base flange 26 ″ may be used. In any embodiment, it will be preferred that any base flange 26 be provided to extend along a plane that is generally parallel with a plane along which the top wall 16 extends, as depicted in FIGS. 5 and 10 . The term “generally parallel” is used as it is contemplated that minor angular positioning or bends in the top wall 16 or the base flange 26 or their orientation with respect to one another may cause a few degrees deviation from parallel, depending upon the circumstances and application at hand.
[0036] The channel 18 should be sized and shaped to substantially enclose one or more of the existing fasteners 28 , which secure the existing building panels 24 to the frame member or purlin 30 of the structure. A new building panel 32 may then be placed into position against the top wall 16 of the bracket 10 . As can be seen in FIGS. 1 and 7 , the height of the bracket 10 defines the spaced relationship between the existing building panel 24 and the new building panel 32 . Therefore, where a larger or smaller distance between the two building panels is desired, the height of the bracket 10 should be fabricated or adjusted accordingly. This may become particularly relevant where an insulative material is to be disposed between the existing building panel 24 and the new building panel 32 . The insulative material may be one of several known insulative materials used generally in the construction industry and should be selected based upon the particular insulating and environmental conditions present for the given job site. The distance between the existing building panel 24 and the new building panel 32 will also become a consideration where the lifting and flexing effects of wind on the building panels is a concern.
[0037] In the embodiment of FIGS. 12-16 , the base flange 26 ′″ cantilevers outwardly from the lower end portion of the first wall 12 and a base flange 26 ′″ cantilevers outwardly from the lower end portion of the second wall 14 .
[0038] In use, the bracket 10 is simply positioned so that the profile of the lower end portion of the first wall 12 and the second wall 14 align with the profile of the existing building panel 24 and the channel 18 substantially encloses one or more of the existing fasteners 28 . In one embodiment, the new building panels 32 may be placed against the top wall 16 and secured in place with new fasteners 34 . However, in a preferred embodiment, the bracket 10 will be pre-located, using one or more base flanges 26 , to ensure proper alignment of the bracket 10 . In one aspect, the first base flange 26 ′ may be used to temporarily tack the bracket in position. With the first base flange 26 ′ extending away from both the first wall 12 and the second wall 14 , a mounting flange is provided to receive a small number of new fasteners 34 that will secure the first base flange 26 ′ with at least an existing building panel 24 , as depicted in FIG. 6 . One or more openings 35 may be provided through the base flange 26 ′, where self-tapping fasteners are not used. Only a small number of fasteners 34 will be required, as permanent mounting will be afforded when the new building panels 32 are secured to the bracket 10 and the structure. Temporarily securing the bracket 10 prevents movement of the bracket 10 with respect to the structure while the new building panels 32 are being located onto the bracket 10 .
[0039] In another preferred embodiment, however, a second base flange 26 ″ is provided, having a leading edge 36 and a depth that extends between the leading edge 36 and the lower end portion of the second wall 14 . The bracket 10 is positioned closely adjacent the outwardly facing surface of the existing building panel 24 so that the leading edge 36 of the second base flange 26 ″ rests closely adjacent at least one existing fastener 28 . The depth of the second base flange is preferably provided so that, when the leading edge 36 of the second base flange 26 ″ is positioned closely adjacent at least one existing fastener 28 , the at least one existing fastener will be positioned adjacent, but not on, an axis that extends perpendicularly through an approximate center of the width of the top wall 16 of the bracket 10 . The reasoning for this will become apparent on examination of FIGS. 6 and 11 , as a new fastener 34 will later be passed through the center portion of the bracket 10 . Accordingly, the second base flange 26 ″ will locate the bracket 10 such that inserting new fasteners along an approximate centerline of the bracket 10 will ensure that the new fasteners 34 are passed through the relevant structures, near the existing fasteners 28 and into the frame member 30 . Positioning both the first base flange 26 ′ and second base flange 26 ″ to extend inwardly, as depicted in FIG. 11 , permit both of the base flanges to serve as position locators. In such an instance, however, a sufficient space should be provided between the leading edges of both base flanges to not only permit the passage of head portions of the existing fasteners 28 but also take into account that existing courses of fasteners may deviate from a straight line.
[0040] Once the bracket 10 has been located with respect to the existing building panels 24 and the existing fasteners 28 , new building panels 32 may be positioned atop the top wall 16 of the bracket 10 . New fasteners 34 can be disposed through the new building panel 32 and into the bracket 10 , existing building panel 24 , and preferably the frame member 30 as well. However, it is contemplated that in certain applications, the new building panel 32 may be secured by engaging the fastener 34 with only the bracket 10 and the existing building panel 24 . The fasteners 34 depicted in FIG. 6 is shown to be a self-tapping screw. However, standard roofing fasteners and the like may all be used, depending on the particular circumstances.
[0041] The first wall 12 and second wall 14 are depicted in FIGS. 5 and 10 as being spaced from one another in an angular relationship, wherein the upper end portions of the first wall 12 and second wall 14 are spaced from one another a distance that is greater than the distance between the lower end portions of the first wall 12 and second wall 14 . However, variations to this shape are contemplated. For example, the first wall 12 and second wall 14 may be positioned to be generally parallel with one another. Moreover, the size and length of the top wall 16 may be varied to provide a larger or smaller surface upon which the new building panel 32 will rest. However, it is preferred that the first wall 12 and second wall 14 be of generally equal length and in a spaced-apart relationship so that a stable forward and rearward footing is provided, which resists forward or rearward tipping or flexing of the bracket 10 and the new building panel 32 . The stability of the new building panel 32 is amplified when used with the bracket 10 and coupled to the frame member 30 , as depicted in FIGS. 6 and 11 . In this manner, the stability of the structure is enhanced by the shape of the bracket 10 but not solely dependent thereon.
[0042] Although the invention has been described in language that is specific to certain structures and methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed invention. Since many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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A bracket or retrofitting panels to a structure is provided with first, second and top walls which define a channel. The channel is sized and shaped to enclose existing fasteners on the structure. A base flange may cantilever from the first or second walls and extend away from the first and second walls to enable a user to secure the bracket to the structure prior to placing new panels on the bracket. Another base flange may cantilever away from the second wall, toward the first wall, and be sized to place a leading edge portion of the base flange adjacent existing fasteners on the structure to locate the bracket before installation and prevent lateral movement of the bracket along existing panels.
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This application is a national phase under 35 U.S.C. 371 of International Application No. PCT/EP2012/063493 filed on Jul. 10, 2012, which claims priority to and benefit of PCT International Application No. PCT/EP2011/061771 filed on Jul. 11, 2011, the entirety of these applications are incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to the field of microscopy with a resolution in the nanometer range. More particularly, the present invention is related to a method for chemical and structural characterization of a sample at high spatial resolution by measurement of light absorbance. The present invention is also related to a microscope implementing such a method.
BACKGROUND OF THE INVENTION AND STATE OF THE ART
Developments in biomedical research and material science rely increasingly on state-of-the-art instruments capable of structural imaging and chemical analysis at very high spatial resolution.
Far-field imaging approaches are usually diffraction limited. In the far field, chemical imaging of small features, such as nanoparticles or nanostructures which fall to a size range below 100 nm, requires thus a breakaway from the diffraction limit. A number of techniques providing chemical imaging at nanoscale resolution have been developed. However, the resolution is then either achieved using near-field techniques or in the far-field by using very short wavelengths (e.g., X-ray, electron microscopy).
In addition to nanoparticles and nanostructures, the nanometer scale is also typical of biological molecules involved in photosynthesis, color-control, and biochemical reactivity. Intracellular analysis in living cells, and the study of large biomolecules generally ranging from 10 to 200 nm, are also of interest.
Progress in these R&D fields requires the development of microscope(s) enabling the chemical characterization of materials with spatial resolution of the order of 1 to 500 nm.
The limited ability to routinely probe and understand the properties of matter at sub-cellular and at nanometer scale hinders progresses and new tools and methodologies need thus to be conceptualized and their effectiveness demonstrated.
Direct measurement of vibrational absorption by optical means requires the use of infrared (IR) beam (wavelength ranges approximately between 750 nm and 1 mm). However, contrary to ultraviolet (UV) and/or to fluorescent microscopy, which uses relatively smaller wavelengths of light (about 10-750 nm), resolutions below the micrometer range seems impossible to achieve in far-field IR microscopy, in view of the limits as expressed by the Ernest Abbe criterion, which forbids spatial resolution better than approximately half of the wavelength of the probe beam.
Chemical bonds in a molecule vibrate at a characteristic frequency. A group of atoms in a molecule may have multiple modes of oscillation. If an oscillation leads to a change in dipole in the molecule, then it will absorb a photon which has the same frequency. The vibrational frequencies of most molecules occur within the infrared light frequency ranges. Because vibrational modes are dependent on composition and on local molecular arrangement, they serve as a fingerprint of molecules, and mapping of the spatial distribution of these modes provides a mean of label-free imaging without the need for any chemically binding additives (labels). This mapping of vibrational signatures is also called chemical imaging, spectroscopic imaging or spectro-microscopy. Current state-of-the-art far-field microscopes affording a mapping of vibrational modes based on CARS (coherent anti-Stoke Raman spectroscopy), vibrational SFG (sum-frequency generation), SRS (stimulated Raman microscopy), or on IRAS (infrared absorption spectroscopy) exhibit a spatial resolution that is at best limited by diffraction.
For microscopy in Fourier Transform Infra Red Absorption Spectroscopy (FT-IRAS) mode using an IR synchrotron source the best resolution that are achieved are then limited to several microns only.
Other instrumental FT-IRAS setup using thermal sources are unable to reach these values due the poor brightness of these sources and generally the resolution is limited to about 20 microns.
Today to achieve higher resolution in IRAS it is necessary to exploit near-field scanning optical microscopies (NSOM), which require to maintain a nanoscale solid probe in the vicinity of the sample and which are thus limited to probing the surface of samples, and exhibit a large technical difficulty due to the poor reliability of probe production and to the necessity to maintain it at nanometer range from the sample. These techniques generally afford spatial resolution of the order of 100 nm.
Although NSOM afford extremely high spatial resolution in IRAS, it seems thus important to consider new techniques to achieve comparable or better resolution in the far-field, which will suppress the limitation to surface-only probing and the engineering challenges related to the nanoscale probe exploitation. However in this case, one needs to find a scheme to achieve in IRAS resolution that overcomes the diffraction limit.
The measurement of the chemical IR absorption with a resolution below the diffraction limit also cannot be done using the techniques developed for sub-diffraction far-field imaging of fluorescence emission. These relies on the controlled suppression of the fluorescence emission (e.g., STED stimulated-emission depletion), or on the localization of randomly activated fluorescent chromophores (e.g., PALM photo-activated localization microscopy, STORM stochastic optical reconstruction microscopy), or on the analysis of Moiré patterns of the emitted fluorescence (e.g., SSIM saturated structured illumination microscopy). These methods of fluorescence imaging are also not label-free since they necessitate the incorporation of fluorescent tag/label in the sample.
Since IRAS probes the intrinsic vibrational modes of molecules, it is thus label-free and it is thus extremely important to find scheme in the far-field that will afford below-the-diffraction-limit resolution for IRAS.
AIMS OF THE INVENTION
More specifically, the invention relates to breaking away from the diffraction limit of infrared absorption and related microscopy.
SUMMARY OF THE INVENTION
The present invention is related to a method for analysing a sample with a light probe at a spatial resolution smaller than the wavelength of the given light probe comprising the steps of:
illuminating the sample by a first light pulse saturating a vibrational and/or electronic transition, said light pulse presenting a spatial distribution of intensity within the sample presenting at least one minimum wherein saturation does not occur, measuring the local absorbance properties and/or the local second order non-linear susceptibility of the sample by using a second light pulse forming the light probe at a wavelength corresponding to said vibrational and/or electronic transition, the second light pulse overlapping said first light pulse intensity minimum.
According to particular preferred embodiment of the invention, the method presents one or a suitable combination of at least two of the following features:
analysis of the sample comprises the step of structural and chemical characterization by determining the local properties of light absorption; the second light pulse is separated from the first light pulse in the temporal domain and illuminates the sample before the relaxation of the vibrational and/or electronic transition saturation occurs; the first and second light pulses present different polarization, and the measurement of the local light absorbance properties and/or the local second order non-linear susceptibility of the sample comprises the step of filtering out the polarized signal arising from the first light pulse by means of a polarizing filter; the first and second light pulse are angularly separated so that the signal arising from the first and second light pulses are angularly separated; the first and second light pulse are separated by means of time-gating, preferably an optically triggered non-linear SFG up-conversion; the transition is non-fluorescent; the first and second light pulses are infrared light pulses, preferably having a wavelength comprised between 1 and 50 μm; the sample is further illuminated by visible light and wherein the detection is performed by Sum-Frequency Generation (SFG); the detection is performed by IR absorption spectroscopy; the spatial resolution is about 1000 to 5 nm, preferably of about 100 to 10 nm; the second light pulse have a wavelength equal to the wavelength of the first light pulse (i.e. the wavelengths are sufficiently close to be absorbed/saturate the same vibrational/electronic transition); the intensity minimum of the first light pulse is induced by an interference device producing-intensity nodes; the first light pulse has a duration comprised between 10 fs and 100 ps, preferably between 500 fs and 20 ps, more preferably about 1 ps; the intensity of the first light pulse is higher than about 0.2 nJ/μm 2 , preferably higher than 2 nJ/μm 2 , more preferably higher than 20 nJ/μm 2 ; the duration of the second light pulse is comprised between 10 fs and 100 ps, preferably between 500 fs and 20 ps, more preferably about 1 ps; the method is repeatedly applied at a repetition rate lower than 10 MHz; the repeated first and second light pulse are scanned in two directions on the sample surface to be able to reconstruct an image of the absorbance and/or second order susceptibility of the sample surface.
A second aspect of the invention is related to a microscope comprising:
at least one light source able to illuminate a region of interest of a sample by a first and a second light pulse, said first light pulse being able to saturate a vibrational and/or electronic transition, first optical means arranged so that the first light pulse presents, in use, at least one minimum of light intensity on the sample, second optical means arranged so that the second light pulse overlap said at least one minimum, detection means for determining absorbance and/or second order non-linear susceptibility of the sample using the second light pulse, said second light pulse having a wavelength corresponding to said vibrational and/or electronic transition, characterized in that the microscope further comprises means for reducing in use the signal arising from the first light pulse on the detection means by timely separating, angularly separating and/or polarizing in different directions, the first and second light pulses or by using slightly different wavelength of the first and second light pulses.
According to particular preferred embodiment the microscope of the invention further comprises one or a suitable combination of the following features:
said at least one light sources is arranged so that the first and second light pulses are timely separated when reaching the sample surface; the at least one light source comprises at least one pulsed laser; the at least one light source comprises one pulsed laser, a beam splitter device such as a partially reflective mirror or a polarizer for splitting each laser pulse into said first and second light pulse, the second light pulse being delayed by optical means from the first light pulse for sequentially illuminating the region of interest by the first and second light pulse; the first optical means comprise an interfering device on the optical path of the first light pulse for inducing light intensity minima of the first light pulse on the sample; the first and second light pulses consist of infrared light; the first and second light pulses are infrared light pulses and the microscope further comprises a visible light source for determining the second order non-linear susceptibility of the sample by measuring a sum frequency generation signal; the microscope of further comprises scanning means for synchronously displacing the intensity minimum of the first light pulse and the position of the second light pulse; the microscope further comprising scanning means for synchronously displacing the sample relative to the laser beams.
Advantageously, the method of the invention does not require heat transfer nor refractive index change nor fluorescent transition.
Advantageously, in the method of the invention, the first light pulse induces a local decrease of the absorbance of the sample and/or the non-linear susceptibility of the said sample.
The method of the present invention is especially well suited for the analysis of crystalline (non amorphous) sample(s).
Advantageously, in the method of the invention, the local infrared absorbance of the sample is measured with spatial resolution smaller than a quarter of the light probe wavelength and/or the vibrational signature of the sample is measured with spatial resolution smaller than a quarter of the infrared probe source wavelength.
Possibly, in the method of the invention, the light probe used has a wavelength laying in the UV-visible-near infrared spectral range between 0.2 to 1.5 μm.
The at least one minimum of intensity of the first light pulse can be defined in the 2 dimensions defined by the sample plane for scanning the sample in two dimensions, the absorption of the sample being averaged in depth, or, as described in the Journal of Microscopy, Vol. 236, Pt 1 2009, pp. 35-43 by Wildanger et Al. for STED measurements, the at least one minimum can also be resolved in depth, so that three dimensional images can be obtained by scanning the sample in three dimensions.
A related aspect of the present invention is a device for microscopy comprising at least a first emission source generating an optical beam, named hereafter the “saturating” beam, and at least a second emission source generating at least one optical beam, named hereafter the “probe” beam, wherein the “saturating” beam excites a vibrational or electronic transition in the material to be analysed, and wherein the “probe beam” measures locally the absorption property or the second order non-linear susceptibility property of the material, and wherein the spatial distribution of the “saturating” beam intensity increases the spatial resolution of the local analysis of the material property by modifying locally its absorption or second order susceptibility.
In this device, two probe beams, one in the visible spectral range, and one in the infrared spectral range are used to measure the local vibrational signature of the material by sum-frequency generation and/or the “saturating” beam is an infrared beam, which (is able to) excites a vibrational transition of the material to be analysed.
Alternatively, in this device, the probe beam is infrared and is used to measure the local IR absorbance of the material to be analyzed, and/or the “saturating” beam is infrared and excites a vibrational transition in the material to be analyzed.
Preferably, in this device, the saturating beam spatial intensity distribution is shaped to present a minimum in its centre in spatial overlap with the probe beam maximum intensity.
The method of the invention advantageously allows for below-the-diffraction-limit IRAS microscopy, preferably with a lateral resolution below 100 nm. Such Infra Red Nanoscopy (IRN) and/or Sum Frequency Generation Nanoscopy (SFGN) on table-top portable architecture are far superior to the state-of-the-art IRAS imaging that requires synchrotron and works at best at diffraction limited resolution of several microns.
The microscopy techniques of the invention can be generically defined as Absorption Saturation Microscopy (ASM), IRN and SFGN being particular cases of this general technique and sometimes defined ASM IR or ASM SFG.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 represents a schematic description of the physical principle of the invention.
FIG. 2 represents the excitation probability (continuous lines) of a vibrational transition as a function of the saturating light pulse fluence and the quenching (dashed line) of the IR and SFG cross section.
FIG. 3 represents an example of intensity profile of the first light pulse (thick line) and the corresponding IR absorption or SFG sensitivity profile (dashed line).
FIGS. 4 a, b and c schematically represent examples of microscope according to the invention.
FIG. 5 graphically represents the resolution obtained when using an example of the invention as a function of the pump pulse energy (shorter dash for higher energy), compared with prior art resolution (broad curve, continuous line).
FIG. 6 schematically represents the geometry of the device used in the example of FIG. 5 . (keys: M mirror, BS beam splitter, DL delay line, OBJ objective, SPL sample, SCNR scanner, MCT detector in the IR, SHTR shutter, ¼WP quarter waveplate, VWP vortex phase plate).
FIG. 7 represents an example of geometry of wave plate (VWP, vortex phase plate) inducing a doughnut like intensity distribution as described in the example.
FIG. 8 represents an example of interference geometry inducing periodical intensity minima, which can be used in the method and the device of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention enables to overcome the diffraction limit in infrared absorption and SFG microscopy.
The present invention proposes a concept for measuring the IR absorption by vibrational modes in a below-the-diffraction limit region of the sample.
The present invention further presents the advantage of working in the far-field, and is applicable to the analysis of different interfaces (solid-air, liquid-solid, liquid-air, liquid-liquid), biologically relevant samples, and other nano-materials.
The device of the present invention enables measuring vibrational signature in samples with spatial resolution more than a decade better than achievable with current state-of-the-art synchrotron-based infrared microscopy.
The device also permits local absorption spectra to be measured in the visible range.
The device relies on the saturation of an optical transition.
The device of the present invention aims at saturating a sample optical transition, which can be vibrational and/or electronic, by a ‘saturating’ pump pulse, and to subsequently ‘probe’ it by Sum-Frequency Generation (SFG) or absorption (infrared, visible or UV) spectroscopy (being preferably IR) using a second light pulse (light probe). In alternative embodiments, or in combination with time separation, the pump beam and the probe beam can be spatially separated (angularly) or separated by using different polarization for the pump and the probe, or by time-gating.
Explanation of the mechanism illustrated in FIG. 1 a : the FIG. 1 a illustrates the well-known concepts of IR absorption spectroscopy (IRAS) and of IR pump-probe spectroscopy, for which both pump and probe pulses are tuned to the wavelength of the vibrational transition, in the IR thus. ( FIG. 1 a left) A pulse of low intensity undergoes partial absorption within a ensemble or sample of two level systems (i.e., molecules or part of a molecule) and the linear absorption of each quanta of light or photon leads to the excitation of one oscillator from the ground state |0 to the excited state |1 .
Competition between stimulated absorption and emission processes prevent the population of |1 to exceed that of |0 , so that a pulse of very high intensity excites at most half the oscillators ( FIG. 1 a centre). The latter situation is defined as the sample saturation. In the pump-probe experiment ( FIG. 1 a right), the same pulse of very high intensity (i.e., enough to saturate the sample) is immediately followed by a delayed probe pulse which does not undergo any absorption for pump-probe delays shorter than the lifetime of |1 .
In other words, the second pulse probes the population of the sample and regions of the sample irradiated by the pump are virtually ‘transparent’ to the probe at short pump-probe delays.
The concept of ASM (or ASM IR or IRN) is depicted in FIG. 1 b . The ‘saturating’ (pump) beam irradiates the sample with an intensity pattern with intensity minima or extinction (nodes). This pump profile is for example readily achieved using a vortex phase plate.
A Gaussian shaped probe, delayed by a time shorter than the lifetime of |1 , irradiates the sample and is transmitted with little change where the intensity of the ‘saturating’ (pump) beam is sufficient to saturate the sample. The transmitted Gaussian probe is reduced where the intensity of the ‘saturating’ (pump) beam is null or not sufficient to saturate the sample.
The energy of the outgoing probe pulse is measured by a detector (integrating device), and the absorbance of the sample in the node of the ‘saturating’ (pump) beam is readily inferred by subtracting the measured energy from the energy of the outgoing probe pulse in the absence of sample. The result of the difference is called the ASM (or IRN or ASM IR) signal. The IRN image is generated by plotting the IRN signal for different position of the sample within the pump and probe beams.
The probe pulses can be either the combination of two pulses, one visible and one infrared, in the case of SFG, one IR pulse in the case of IRAS, or one visible pulse in the case visible-UV absorption spectroscopy.
The sub-diffraction resolution results from the non-linearity of the ‘saturation’ and thus of the quenching of the second order non linear susceptibility or of the absorbance of the sample with respect to the local optically patterned ‘saturating’ pump pulse intensity.
The principle is illustrated numerically in the case of SFG and IR absorption spectroscopy in the following FIGS. 2 and 3 .
FIG. 2 shows the excitation probability of a vibrational transition at 3 μm, modeled as a two level system, irradiated resonantly by an infrared laser pump pulse. The thick black curve is calculated in the Markov approximation, i.e. by neglecting Rabi Oscillations and vibrational relaxation.
This curve verifies
N 1 = 1 - ⅇ - CF 2 , ( 1 )
where N 1 , is the excited level population and F, the fluency of the ‘saturating’ pump pulse. From equation (1), the inventors define the saturation fluency F s as:
F
s
=
1
C
.
(
2
)
The saturation of the vibrational transition induces the quenching of the its susceptibility for SFG and IR absorption spectroscopy, as shown in FIG. 1 by the discontinuous lines which obeys the following equation, respectively:
Abs
IR
∼
(
1
2
-
N
1
)
(
4
)
Although it is not a unique experimental configuration, for this numerical illustration, the inventors use a simple interference pattern, generated by dividing the “saturating” pulse in two and focusing the resulting beams in a counter propagating geometry on the sample, to illustrate the concept of IRN. These “saturating” beams will generate on the sample a stationary wave with intensity extinction nodes separated by half the wavelength used, that is 1.5 μm if the inventors select a wavelength of 3 μm typical for vibrational excitation in organic samples, as shown by the thick curve in FIG. 3 . FIG. 3 also shows the SFG and IR absorbance (discontinuous line) profiles for the same vibrational excitation after saturation and prior to de-excitation.
The sample parts (for example molecules) with a vibrational mode at 3 μm, and situated in the maximum intensity of the “saturating” stationary wave will be saturated and consequently their IR absorbance and/or SFG cross section will be quenched. Therefore the discontinuous curves represent the local contribution to the SFG and IR signals, as a function of their position in the “saturating”—(or “quenching” or pump) pattern.
The curves in FIG. 3 have been calculated assuming that fluency at the maxima of the “saturating” (pump) patterns is 100 times higher than Fs., defined in equation (2). In such condition, the inventors observe that a spatial resolution of 60 nm (full width at half maximum) is achieved. In similar condition, but the “saturating” (pump) maxima only 10 times higher than Fs, the achieved spatial resolution would still be ˜ 150 nm.
The inventors have developed a set of characteristics for the ideal laser for IRN. First, the “saturating” pump beam must be focused at the diffraction limit on the sample. For a pump beam at 3 μm, with diameter of 25 mm, focused using a lens of focal length 50 mm, at 65 deg incidence on the sample, the inventors obtain an elliptical spot of 10 μm×23 μm, equating to 230 μm 2 .
The inventors have saturated CH and CO vibration modes with 10 ps long pulses and fluency level of 40 nJ per 230 μm 2 . The IRN method requires therefore in those cases IR pulses with energies of the order of 4 μJ per 230 μm 2 .
The probe pulses for SFG or IR absorption spectroscopy can be (should be) much below the saturation level, e.g. of the order of 10 nJ.
The weak SFG signal or IR absorption signal, per pulse, must be compensated by a high repetition rate in order to obtain a globally measurable signal for nanoscale sample volumes. The repetition rate is preferably limited to 5-30 MHz, preferably to 5-15 MHz, and more preferably to about 10 MHz, because of the sample temperature relaxation time. The IR probe beam power can therefore be of the order of 50-300 mW, preferably 50-150 mW, and more preferably ˜ 100 mW and will permit to generate SFG signal intensities comparable to these obtained with existing SFG setup dedicated to microscopic samples.
The saturating-quenching beam for the IRN or SFGN (ASM-SFG or ASM-IR absorption spectroscopy), should be achieved from infrared picosecond pulses of duration of the order of 1 to 10 ps (with bandwidth of about 10 to 1 cm −1 , close to the Fourier transform limit), pulse energy of the order of 4 μJ, and high repetition rate in the range of 1 kHz to 10 MHz, corresponding to an average power between 0.004-40 W.
This example of specifications demonstrates that the technology of synchronously pumped optical parametric oscillator (OPO) built around periodically polled LiNbO 3 crystals, and pumped by fiber lasers or Ti-Sapphire regenerative amplifier can fulfill the requirements for IRN. The specifications are not unique. Higher energy pulses, with lower repetition rates, can be also be used for chemical imaging of larger samples using more complex ‘saturating’ interference patterns.
FIG. 4 a schematically represents an example of a microscope according to the invention. In such a microscope, a pulsed laser beam 1 is splitted into a first pulsed “saturating” laser beam 2 and a second pulsed “probe” laser beam 3 by means of a beam splitter 5 . The “saturating” and “probe” laser beams are focused onto the sample 4 by means of lenses or Schwarzschild objectives 8 , 10 . The synchronization of respective delay between the “saturating” and “probe” beams is adjusted using a delay line 11 .
The ratio of the light intensity transmitted through the beam splitter on the light intensity reflected by the beam splitter is defined by the intrinsic reflectivity of the beam splitter 5 . Preferably, in the invention, the first beam represents 90 to 99% of the total light.
In order to define an intensity minimum in the “saturating” beam intensity distribution, interference is used. In the example of FIG. 4 a , the interference is obtained by generating a standing wave using two counter propagating beams.
Finally a detector 6 is used to measure the signal of interest.
In order to simplify the synchronization of the x-y displacement of the first and second pulsed laser beam relative to the sample 4 , it is preferably the sample 4 which is displaced in x-y directions relative to the pulsed beams. This may be done for example by using piezoelectric sample holder, such as those used in near field microscopy (AFM, STM . . . )
FIG. 4 b represents another example of microscope according to the invention wherein the “saturating” (pump) and “probe” pulse are counter-propagating in the sample. The interfering device 9 is possibly a vortex wave plate that will generate a doughnut intensity profile of the saturating pulse intensity in the focal plane of the sample. Mirror 12 must be only slightly reflective to steer part of probe pulse towards the detector while being highly transparent to the saturating pulse.
FIG. 4 C represents another example of microscope according to the invention where the “saturating” (pump) and “probe” pulse are co-propagating towards the sample. The probe pulse can possibly be selectively detected using synchronous (time-gated) detection, by means of a non-linear process such as sum frequency generation in a non-linear material 13 with a reference pulse 14 .
EXAMPLE
The following example illustrates how to use the method to record the IRN (or ASM IR) signal.
This example illustrates a computed simulation of the mapping of a vibrational mode absorption with a resolution below the diffraction limit, and defines an example of IRN point-spread function (PSF). To define the PSF in this example, one uses two different intensity profiles for the pump and one records/integrates the intensity/energy of the probe in both cases.
The difference between probe intensities is defined in this example as the IRN signal and has a PSF that is punctual and has a below-the-diffraction-limit full-width at half maximum (i.e., the fwhm is a measure of the microscope resolution). The discussion concerns a measure in transmission geometry but also applies to a measure in reflection geometry.
The following IRN PSF simulation uses a simplified model of Einstein for the absorption.
A sample corresponding to a self-assembled film of octadecylsilane is used in this realistic case-study of an organic thin film. The sample has been patterned in such a way that the molecules are confined in a region of 25×25 nm 2 . That dimension is small with respect to the expected resolution for IRN, and thus computing the IRN images will provide a simulation of the PSF (i.e., the image of a small punctual object). The fwhm of the PSF is a direct measure of the resolution.
The sample is modeled in space as an ensemble of voxels (volumetric pixels, or 3D pixels) containing each a collection of independent oscillators and the temporal evolution of the relative population density N of the oscillators in the excited state |1 reads in Cartesian coordinates:
ⅆ N ⅆ t = - Γ ( r ) N ( r ) - β ( r ) Δ N ( r , t ) I ( r , t ) , ( 5 )
where Γ is the deexcitation rate of |1 , β is the stimulated emission/absorption Einstein coefficient, ΔN is the difference in relative population density between the levels |1 and |0 , I(r,t) is the local intensity at a given sample voxel, r=(x,y,z) is the voxel position with z the coordinate along the propagation axis and (x,y) the coordinates in the sample plane, and t is the time. The intensity is computed from:
ⅆ I ⅆ z = hc λ β ( r ) ρ ( r ) Δ N ( r , t ) I ( r , t ) , ( 6 )
with h and c the Planck constant and the speed of light in vacuum, and ρ is the density of oscillators in a given voxel.
A Mathlab code was used to solve the system of equations, developed using the backward Euler approach and independently for each set of (x,y) coordinates. The solution is readily found by iteration with the boundary conditions N(r,t 0 )=0, where t 0 is a reference time before irradiation of the sample, and I(x,y,z 0 ,t) describing the temporal evolution of the intensity impinging the sample at z 0 (i.e., for co-propagative pump and probe pulses in transmission).
The departing probe pulse energy Σ was computed by integrating the intensity in the sample plane (x,y) and over time, at the coordinate z exceeding the sample thickness. IR absorption images and sub-diffraction IRN images were computed by repeating the calculation whilst varying the relative position of the sample with respect to the pulses. The IR absorption (i.e., diffraction limited image of the IR absorption) and the IRN images are defined respectively by
IR ( % ) = ∑ ( z 0 ) - ∑ ∑ ( z 0 ) × 100
and ( 7 ) by IRN ( % ) = ∑ Gauss - ∑ vortex ∑ Gauss × 100 , ( 8 )
where Σ(z 0 ) is the probe pulse energy incident on the sample, and Σ Gauss and Σ vortex are the probe pulse energy transmitted through the sample following a Gaussian or a vortex (i.e., nodal profile, see below) pump pulse, respectively. The calculation neglects scattering and diffraction in the sample, which is justified since its thickness is of a few microns maximum, and thus typically shorter than the wavelength, and since the whole transmitted intensity is integrated over the sample plane.
In the focal plane, the spatio-temporal intensity profile of the Gaussian pulses (i.e., zeroth order) is defined by
h Gauss ( r,t )= h Gauss 0 e −r 2 /w 0 2 e −(t−Δt) 2 /τ 0 2 (9)
where r and θ are the polar coordinates in the plane normal to the direction of propagation, and where the full width at half maximum (fwhm) of the Gaussian is defined by 2√{square root over (ln(2))} w 0 (w 0 being the Gaussian waist) and a temporal pulse duration by 2√{square root over (ln(2))} τ 0 . h Gauss 0 is a constant adjusted to reproduce pulse energies ranging from 1.0 nJ to 1.0 μJ for the Gaussian pump pulses and 0.1 nJ for the probe. Δt is zero for the pump pulses and set to a finite value for the probe, marking the pump probe delay.
The nodal intensity profile is set to that of a vortex whose wavefront evolves has a spiral along the direction of propagation and that corresponds to a first order Gaussian mode. The intensity in the focal plane is written
h vortex ( r,t )= h vortex 0 r 2 e −r 2 /w 0 2 e −(t−Δt) 2 /τ 0 2 (10)
with h vortex 0 adjusted to the desired pump energy. These profiles are experimentally achieved by inserting in the beam path of an originally Gaussian pulse a vortex phase plate, inducing a progressive change of phase of 2π for a complete rotation of θ. Such vortex phase plates are for example commercialized by RPC Photonics (Rochester, N.Y., U.S.A.).
Aiming to a realistic prediction of the IRN microscopy performances, the fwhm of the pulses were adjusted to those expected with objectives of numerical aperture (NA) 0.7 and 0.85. The first value is chosen because it is the maximum reported NA for reflective objective and is used in synchrotron IR absorption microscopy and the second value because IR lenses at 3.5 μm with a NA of 0.85 are commercially available. Although better resolution is expected for larger NA value, the achromatic behavior of the reflective objectives makes them of very high interest in IR absorption microscopy. At the diffraction limit, these objectives focus a Gaussian beam (λ at 3.5 μm) to a spot of fwhm ca. 2.4 and 1.9 μm, respectively. The beam waist w 0 defined above is adjusted to these expected fwhms.
Pump-probe spectroscopy of vibrational modes is best achieved with picosecond-long pulses, affording suitable time resolution without compromising too much on the spectral resolution. A duration of 1.0 ps was then chosen for all pulses.
As shown in FIG. 5 , the diffraction limited PSF for IR absorption microscopy (state of the art synchrotron IRAS) exhibits a fwhm of 1.9 μm, equivalent to that of the probe. The fwhm for IRN is on the other systematically below the diffraction limit and down to ca. 100 nm for a pump of 1 μJ.
The proposed example of embodiment affords thus the generation of a PSF without the need for generating any further reference measure. A schematic of the exemplified IRN microscope is described in the FIG. 6 for counter-propagative pump and probe pulses.
The sample absorbance/IRN signal is measured in transmission and placed between two high NA objectives (preferably but not necessarily reflective objective). The sample is placed on a scanner (alternatively the beam can be scanned).
The IR laser (tuned to the vibration wavelength) is split to create the pump and probe beams. The path of the pump beams (split again in two) are adjusted to be a little shorter than the probe one using the delay lines. One pump beam is shape to a nodal profile using a vortex phase plate. Rapid shutter allows for selecting either of the two pumps.
The pumps are counter-propagative with respect to the probe (possible for a transparent sample). The probe is detected by a detector and the signal integrated. An imaged is generated by recording the difference of the values at the detector for each pump whilst scanning the sample with respect to the pump/probe beams. A lockin amplifier can be used for measurement of the said difference.
The invention is also described in the priority document PCT/EP2011/061771 which incorporated herein by reference.
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A method for analyzing a sample with a light probe with a spatial resolution smaller than the wavelength of the light probe comprising the steps of: —illuminating the sample by a first light pulse saturating a vibrational and/or electronic transition, said light pulse presenting an intensity spatial distribution on the sample presenting at least one minimum wherein saturation does not occur, —measuring the local absorbance properties and/or the local second order non-linear susceptibility of the sample by using a second light pulse forming the light probe at a wavelength corresponding to said electronic and/or vibrational transition, wherein the second light pulse overlap said first light pulse intensity minimum.
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BACKGROUND OF THE INVENTION
This invention relates to apparatus and a method for the forming of elongated hollow metal sections into a predetermined shape or contour. It relates particularly to apparatus and a method for the bending or shaping of elongated hollow metal sections, such as aluminum extrusions, using "stretch forming" apparatus and methods. The stretch forming process for bending or shaping of an aluminum extrusion involves placing the ends of the extrusion into an opposed pair of jaws or clamps attached to a pair of opposed hydraulic cylinders and then applying sufficient tension through the hydraulic cylinders and jaws or clamps on the ends of the extrusion to "stretch" the metal in the extrusion beyond its yield point or elastic limit. While the metal is tensioned above the elastic limit, a forming die of desired shape and contour is pressed against the extrusion causing the extrusion to assume the desired shape and contour of the forming die. The tension on the ends of the extrusion is then reduced and the newly shaped extrusion is removed from the forming die and the stretch forming apparatus.
In the past, the stretch forming of elongated hollow metal sections, and especially thin walled aluminum extrusions, often produced crimps or wrinkles in certain portions of the walls of the section or extrusion as a result of the inability of the walls to resist the reshaping forces during the stretch forming operation. Such crimps and wrinkles not only weakened the extrusion but also resulted in an extrusion of unacceptable appearance.
While in some cases the crimps and wrinkles could be eliminated by using a thicker walled section, such a solution added to the cost of the finished product and increased its weight. U.S. Pat. No. 4,803,878 issued Feb. 14, 1989 to Moroney not only discloses the above-described apparatus and process for "stretch forming" of elongated hollow metal sections or extrusions, but also discloses one proposed solution to eliminate the crimps and wrinkles formed in the reshaping of thin walled extrusions. Moroney suggests that the crimps and wrinkles can be reduced or eliminated by introducing a gas under pressure into the interior of the elongated hollow metal section or extrusion while it is being stretch formed. Moroney claims that the internal gas pressure is sufficient to support the internal walls of the extrusion during the stretch forming operation and will prevent the formation of crimps and wrinkles. While the use of an internal pressurized gas has helped to reduce the formation of crimps and wrinkles, the use of the internal pressurized gas alone has not completely eliminated crimps and wrinkles in elongated hollow metal sections or extrusions of complex cross-sectional shape and has increased the reshaping cycle time and cost required to produce an acceptable finished product by the "stretch forming" process.
It has been known to use both external and internal mandrels to prevent the crimping and wrinkling of tubing, pipe and other hollow elongated metal sections while they are being bent. Some of the known mandrels are bendable or flexible to allow support by the mandrel throughout the bending operation. U.S. Pat. No. 3,747,394 to Cunningham discloses a flexible, expandable internal mandrel used to bend large diameter pipe. The mandrel is supported internally within the pipe on rollers. Cunningham's mandrel uses a plurality of pipe engaging shoes that are clamped tightly in place against the pipe by plurality of toggle joints.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide apparatus and a method useful for the stretch forming of elongated hollow metal sections which will resist crimping or wrinkling of the elongated hollow metal section as it is being reshaped during the stretch forming operation.
It is another object of this invention to provide apparatus and an associated method that allows the stretch forming of elongated hollow metal sections into a finished or semi-finished product having accurate dimensions, contours and a smooth appearance.
It is still another object of this invention to provide apparatus and an associated method for the stretch forming of elongated hollow metal sections that can be easily adapted to existing stretch forming equipment and practices without an increase in the reshaping cycle time or increase in costs.
It is another object of this invention to provide apparatus and an associated method for the stretch forming of elongated hollow metal sections that can be adapted for the forming and shaping of a wide variety of cross sections of elongated hollow metal sections and extrusions.
We have discovered that the foregoing objects can be attained by providing apparatus and an associated method for the stretch forming of an elongated hollow metal section into a predetermined contour comprising means to grip the opposed ends of the elongated hollow metal section, a forming die member having a forming die face adapted to reshape the elongated hollow metal section and a collapsible and expandable articulated mandrel positioned inside the elongated hollow metal section. The apparatus includes means to tension the elongated hollow metal section above its elastic limit. The internal articulated mandrel is comprised of two diametrically opposed groups of articulated support members connected by elastomeric spacers. Each group of articulated support members may be connected to a common reversible drive shaft by links which cause the collapse or expansion of the mandrel. The mandrel, when expanded, supports selected positions of the inner periphery of the elongated hollow metal section and is adapted to constrain the forces on the inner wall surfaces of the elongated hollow metal section while it is reshaped by the forming die member under tension.
In applying this apparatus to the method of this invention, the articulated mandrel is inserted into the interior of the elongated hollow metal section and expanded to support selected portions on the inner periphery of the the metal section, tension is then applied to the ends of the metal section until the section is tensioned above its elastic limit. The metal section is then reshaped to the desired contour or shape against a forming die member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a typical stretch forming apparatus used to reshape elongated hollow metal sections and illustrating the apparatus with a hollow metal section in the apparatus prior to the stretch forming operation.
FIG. 2 is a top plan view of the same stretch forming apparatus shown in FIG. 1, illustrating the hollow metal section as it is being stretch formed by the forming die member while the metal in the hollow metal section is tensioned above its elastic limit.
FIG. 3 is a cross-sectional view of the mandrel used in the apparatus of this invention while in a collapsed state to permit its insertion or removal from the interior of the hollow metal section.
FIG. 4 is a cross-sectional view similar to FIG. 3 showing the mandrel used in the apparatus of this invention in an expanded state.
FIG. 5 is a section taken along the section lines V--V of FIG. 3.
FIG. 6 is a section taken along the section lines VI--VI of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate a typical apparatus and methods used to "stretch form" an elongated hollow metal section, such as an aluminum extrusion. As shown in FIGS. 1 and 2, the stretch forming apparatus 1 comprises an elongated foundation bed or table 2 having a pair of carriages 3 and 4 at each end of the bed or table 2. The carriages 3 and 4 are positioned on the bed or table 2 a suitable distance apart for the length of the extrusion to be stretch formed and then locked into place. The carriages 3 and 4 do not move during the stretch forming operation.
Each of the carriages 3 and 4 is equipped with a clamp or jaws 5 which are designed to tightly grip and hold the ends of the extrusion 6 to be reshaped and stretch formed. Each of the carriages 3 and 4 are also provided with hydraulic pistons and cylinders 7 to provide a tensioning force to the ends of the extrusion 6 when gripped in the clamps or jaws 5.
The stretch forming apparatus 1 is provided with a die member 9 mounted on a movable die carriage 10. The die carriage 10 and the die member 9 are able to be moved transversely to the axis of the foundation bed or table 2 along parallel guide rails 12 by a hydraulic piston and cylinder 11. The die member 9 has a die face portion 13 shaped to provide the desired curve or contour to the extrusion 6 and is often provided with a die cavity machined into the die face portion 13 to accommodate at least a portion of the cross section of the extrusion 6 be stretch formed.
As shown in FIG. 2, the reshaping or stretch forming of the extrusion 6 is performed by first activating the tension pistons and cylinders 7 attached to the clamps or jaws 5 which tightly hold the ends of the extrusion 6. Enough tension is applied to the ends of the extrusion 6 to exceed the elastic limit of the metal in the extrusion and thereby place the metal in the "yield state" where the metal is susceptible to easy reshaping and forming. Once the metal is tensioned to the "yield state", the die carriage 10 and the die member 9 are moved forward by the hydraulic piston and cylinder 11 along the guides 12 until the die member reshapes the extrusion 6 into the desired contour or shape, as illustrated in FIG. 2. Also illustrated by FIG. 2 and more fully described in the above-mentioned U.S. Pat. No. 4,803,878 to Moroney, the clamps or jaws 5 are permitted to pivot to provide the proper angle tangent to the curve being formed in the extrusion 6.
During the reshaping operation by the die member 9, selected portions of the internal wall surfaces of the extrusion 6 are supported by the collapsible and expandable articulated mandrel 15 to resist any forces that would tend to wrinkle or crimp the walls of the extrusion 6.
In FIGS. 3, 4, 5 and 6, we have illustrated a preferred embodiment of the collapsible and expandable articulated mandrel 15 of this invention. In FIGS. 3 and 5, the mandrel 15 is shown in a collapsed position to permit its insertion or removal from the interior of the extrusion 6. In FIGS. 4 and 6, the mandrel is shown in an expanded position to support selected portions of the inner periphery of the extrusion 6 and constrain the forces on the walls of the extrusion 6 during the stretch forming thereof.
The collapsible and expandable articulated mandrel 15 of this embodiment comprises two groups of a plurality of closely spaced, articulated support members 16, each about 1/4 to 1/2 inches thick and made of steel, aluminum, plastic or similar hard materials, machined to a contour to fit into selected portions of the extrusion 6, as best illustrated in FIGS. 5 and 6. The closely spaced support members 16 are connected together into a group by flexible elastomeric spacers 17, each about 1/4 to 1/2 inches thick, and made of rubber or other elastomeric material to form a group of interconnected closely spaced support members 16.
The diametrically opposed groups of the support members 16 are designed to fit tightly, when expanded, in selected portions of the inner periphery of the extrusion 6. The cross-sectional shape of the support members 16 conforms to the interior cross-section of selected diametrically opposed portions of the extrusion 6, as best illustrated in FIGS. 5 and 6. As illustrated in FIGS. 5 and 6, the cross-sectional shape of the support members 16 in one group will often be different from the cross-sectional shape of the support members in the other group in order to fit within the selected portions of the extrusion 6.
The closely spaced support members 16 and the elastomeric spacers 17 allow the mandrel 15 to flex and rotate slightly during the stretch forming operation and the movement of the die member 9, and still provide sufficient internal support to the walls of the extrusion 6.
In the preferred embodiment of this invention, the two diametrically opposed groups of support members 16 are connected to a central, threaded common drive shaft 18 by parallel links 19, as shown in FIGS. 3, 4, 5 and 6, which allows the mandrel or be expanded or collapsed by rotation of the the shaft 18.
In use, the mandrel 15 is inserted into the interior of the extrusion 6 in a collapsed position, as shown in FIGS. 3 and 5. The mandrel 15 may extend within the extrusion 6 for the full length of the forming die face 13 or just in selected shorter portions of the extrusion 6 depending on the nature and extent of the reshaping required for the extrusion 6. The mandrel 15 is inserted, either manually or with a power assist, to the proper position in the extrusion 6 before starting the stretch forming operation. The central drive shaft 18 is then rotated manually or with a power source, causing the links 19 to move, in parallel, to a position substantially perpendicular to the longitudinal axis of the extrusion 6 and thereby forcing both groups of support members 16 tightly against selected portions of the inner wall surface of the extrusion 6. The mandrel 15 is held in this expanded position until completion of the stretch forming operation. Reversal of the drive shaft 18 then allows for the collapse of the mandrel 15, allowing it to be easily removed from the interior of the extrusion 6 at the completion of the stretch forming operation.
The mechanism associated with the drive shaft 18 and links 19 may be threaded toggles, cam levers or rack and pinion links to transmit the rotary movement of drive shaft 18 to transverse movement of the links 19.
It is understood that this embodiment is just one example of the apparatus of this invention and is provided for the purposes of illustrating this invention and not for the purpose of limitation.
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Disclosed is apparatus and a method for the stretch forming of an elongated hollow metal section, such as an aluminum extrusion. The apparatus and method of this invention uses a collapsible and expandable articulated mandrel positioned inside portions of the elongated hollow metal section to constrain and support the internal wall surfaces of the elongated hollow metal section against the reshaping forces imposed on the interior of the hollow metal section during the stretch forming operation. The mandrel disclosed herein prevents the formation of wrinkles and crimps being formed in the walls of the elongated hollow metal section during the stretch forming and reshaping thereof.
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RELATED APPLICATIONS
This application is a Continuation-in-Part of application Ser. No. 08/801,928 filed on Feb. 15, 1997, now U.S. Pat. No. 5,810,392, which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to an apparatus for sensing the presence and weight of an occupant of a vehicle seat.
BACKGROUND OF THE INVENTION
Many vehicles are equipped with safety devices such as airbags and seat belt pretensioners to protect persons occupying various seats in the vehicle. If a seat is unoccupied or is occupied by a person of a particular size, it may not be necessary to activate a safety device associated with that seat. Furthermore, if a seat is occupied by a person of a particular size the manner in which a safety device is employed may be varied accordingly. One indicator of the seat occupant's size is the occupant's weight. In the case of an infant, the combined weight of the infant and an infant safety seat is useful as an indicator of occupant size. U.S. Pat. Nos. 5,232,243 and 5,494,311 teach a seat occupant sensor that is a piezoelectric film which is rigidly mounted to a substantially inflexible bottom portion of the seat. A plurality of sensing elements are arranged in rows and columns forming an array. U.S. Patent No. 5,454,591 teaches the use of this sensor to determine if a vehicle seat is occupied by an occupant weighing up to 40 pounds (about 18.2 kilograms) or more than 40 pounds (about 18.2 kilograms) and send an appropriate signal to a safety device control unit.
U.S. Pat. No. 5,474,327 teaches a seat occupant presence, weight and position sensor system wherein a plurality of sensors are located in the seat base just beneath the seat cover and some pressure is exerted on the sensors by the seat cover. The preferred sensors are mounted between polymer sheets and include a pair of conductive electrodes about 2.54 centimeters (1 inch) in diameter separated by carbon layers such that resistance between electrodes decreases as pressure increases.
U.S. Pat. No. 5,161,820 teaches a seat occupant sensor which is a switch, preferably a flat mat-like contact switch wherein two contact layers are separated by an intermediate, elastically deformable, electrically conductive layer. The contact switch is mechanically activated when the seat occupant compresses the intermediate layer and completes a conductive pathway for the switching circuit. The use of a simple physical contact switch or a condenser-type switch is also disclosed. However, the seat structure incorporating any of these switches is not shown in the drawings or described in the specification. The seat occupant sensor taught in this patent employs sensors located both in the seat and in the floor in front of the seat.
U.S. Pat. No. 4,678,058 teaches a vehicle seat switch assembly including a generally C-shaped spring located underneath the seat cushion. The end portions of the spring are displaced laterally when the spring is depressed when the seat is occupied. The lateral displacement of the spring ends pulls a switch plunger to close the switch.
U.S. Pat. Nos. 5,413,378 and 5,439,249 teach the use of an occupant weight sensor located in or on a structure that includes a seat cushion. The exact structure and operation of the occupant weight sensor is not disclosed in either of these patents. U.S. Pat. No. 5,466,001 teaches the use of sensors embedded in a seat cushion and seat back to sense occupant presence, but the structure of the sensors is not disclosed. U.S. Pat. No. 5,109,945 also teaches the use of a seat switch to detect a seat occupant but does not disclose the structure of the switch or the manner of incorporating the switch into the seat.
U.S. Pat. No. 5,481,078 teaches a seat occupant sensor wherein the seat rails pivot about their forward end against leaf springs designed to support the seat weight plus a known fraction of the occupant's weight so that the rear of the seat is raised when the seat is unoccupied. When the seat is occupied, the rear of the seat moves down and an electronic sensor detects seat position to provide a position signal.
U.S. Pat. Nos. 4,655,313; 4,361,741; and 4,509,614 also teach a vehicle seat switch used with a seat which pivots relative to the front of the seat cushion.
U.S. Pat. No. 5,120,980 teaches a foam seat cushion confining wire mesh electrical switch closing contacts. U.S. Pat. No. 5,164,709 teaches a seat occupant sensor which is a lateral-force-sensitive cable laid in a meandering pattern foamed into the seat cushion.
U.S. Pat. No. 4,806,713 teaches a seat-contact switch for generating a "seat occupied" signal when a seat suspension approaches a seat frame as a result of seat loading. An articulatable device is fastened on one end to the seat suspension and on the other end to the seat frame. U.S. Pat. No. 4,607,199 teaches the use of a seat switch in conjunction with a microprocessor to disable operation of a vehicle if the seat occupant is out of position for a given period of time. The switch structure and manner of incorporating the switch into the seat are not disclosed.
EP 0 728 636 A1 teaches the use of a switch sensor switch disposed in a seat base but does not disclose the switch structure and manner of incorporating the switch into the seat.
U.S. Pat. No. 4,633,237 teaches an occupant sensor for a hospital bed including a plurality of sensors defining interstices of a matrix of such sensors. The matrix is woven into a mat for placement on a bed in which a patient is confined.
SUMMARY OF THE INVENTION
A seat occupant sensing system for determining the weight of the seat occupant of this invention has a seat pan which is rigidly mounted to a seat frame which attaches to a vehicle body. A seat cushion on which the occupant sits is positioned over the seat pan. A rigid frame, or insert, is positioned above the seat pan and receives and supports the weight of the occupant. The rigid frame is supported on four sensors which in turn are mounted on the seat pan. The sensors collectively measure the weight supported by the rigid frame and thus determine the weight of the seat occupant. The sensors used to measure the weight of the seat occupant can be of two basic types.
The first type is a load cell which experiences very little displacement and directly measures the imposed load. Load cells typically employ strain gauges, piezoresistive, capacitive or piezoelectric sensors. The second type of sensor employs a spring, the springs have a spring constant which controls the amount of displacement for a given load. A displacement sensor measures the amount the spring is compressed which is used to determine the load on the spring. The displacement sensor of this invention will preferably employ a Giant Magnetoresistive Effect (GMR) Sensor.
There is provided in accordance with the present invention a seat occupant sensing system comprising: (a) a seat having a seat support member and a seat pan member fastened to one another; (b) a frame disposed vertically above the seat pan in a spaced apart vertically juxtaposed relationship with the seat pan, the frame underlying a portion of a seat cushion; and (c) at least two sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via the sensors which sense the magnitude of the force transferred therethrough and send signals to a device which processes the signals to determine the weight that the portion of the seat cushion is bearing.
There is provided in accordance with yet another aspect of the present invention a seat occupant sensing system comprising: (a) a seat having a seat support member and a seat pan member fastened to one another; (b) a frame disposed vertically above the seat pan in a spaced apart vertically juxtaposed relationship with the seat pan, the frame underlying a portion of a seat cushion, the portion of the seat cushion being spaced apart from a rear edge of the seat cushion; and (c) at least two sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via the sensors which sense the magnitude of the force transferred therethrough and send signals to a device which processes the signals to determine the weight of the load disposed on the portion of the seat cushion bearing on the sensor.
There is provided in accordance with yet another aspect of the present invention a seat occupant sensing system comprising: (a) a seat having a seat support member and a seat pan member fastened to one another; (b) a frame disposed vertically above the seat pan in a spaced apart vertically juxtaposed relationship with the seat pan, the frame underlying a portion of a seat cushion, the frame and the seat pan being at least partially retained in the vertically juxtaposed relationship by a tension member; (c) at least two sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via the sensors which sense the magnitude of the force transferred therethrough and send signals to a device which processes the signals to determine the weight that the portion of the seat cushion is bearing; and (d) a controller which processes a signal from the weight determining device to control the activation of at least one safety device for an occupant of the seat based upon the weight.
There is provided in accordance with yet another aspect of the present invention a kit for retrofitting a vehicle seat with a seat occupant sensor system comprising a frame having a plurality of sensors mounted thereon in locations which correspond to a vertically uppermost surface of a vehicle seat pan and a device which processes signals from the systems to determine the weight that is located above and resting upon the frame.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded isometric view of a typical prior art vehicle seat.
FIG. 2 is a perspective view of the bottom side of a prior art seat cushion used with the prior art seat shown in FIG. 1.
FIG. 3 is an exploded isometric view of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 4 is a front elevation view of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 5 is a side elevation view of the vehicle seat equipped with an occupant sensing apparatus of FIG. 4.
FIG. 6 is a top view of the vehicle seat equipped with an occupant sensing apparatus of FIG. 4.
FIG. 7A is a perspective view of the top side of a frame with sensors mounted thereon.
FIG. 7B is a perspective view of the bottom side the frame with sensors mounted thereon of FIG. 7A.
FIG. 8 is a cross-sectional side view of the vehicle seat equipped with an occupant sensing apparatus of FIG. 4 taken along section line 8--8.
FIG. 9 is a top view of a vehicle bench type vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 10 is an enlarged fragmentary view of a sensor located between rigid components of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 11 is a schematic view of an occupant sensing apparatus in accordance with the present invention.
FIG. 12 is an exploded isometric view of an alternative embodiment vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 13 a cross-sectional side view of the vehicle seat equipped with an occupant sensing apparatus of FIG. 12.
FIG. 14 is an enlarged fragmentary view of a sensor located between rigid components of the alternative vehicle seat design of FIG. 12 which is equipped with an occupant sensing apparatus in accordance with the present invention.
FIG. 15 a cross-sectional side view of a vehicle seat equipped with an alternative embodiment occupant sensing apparatus in accordance with the present invention.
FIG. 16 is an enlarged fragmentary view of a sensor located between rigid components of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention;
FIG. 17 is a side elevational cross-sectional view of the alternative sensor of FIG. 15.
FIG. 18 is a pictorial plan view of a Giant Magnetoresistive (GMR) circuit employed in the sensor of FIG. 17.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to FIGS. 1-18, wherein like numbers refer to similar parts, in FIG. 1 there is shown an exploded view of a typical prior art vehicle seat. A vehicle seat has a seat cushion 10 and a seat back 12. The seat back may have a head rest 13 associated therewith. The seat back may be pivotally attached to the remainder of the seat. The seat cushion 10 is made of a comfortable, supportive but compressible material, for example foam rubber. The seat has a rigid seat support member 16, sometimes referred to as the seat frame. The rigid seat support member may be unitary, as shown in FIG. 1, with a cross member extending between two side rails, or the side rails may only be joined to one another by the seat back and maintained parallel to one another by fastening the seat frame to legs which extend between the seat frame and the floor of the vehicle.
A seat pan 18 supports the seat cushion 10, which is adapted to be secured thereto by having a bottom side 11 that is contoured, as shown in FIG. 2, to be complementary to the seat pan 18. The seat pan has a generally rectangular shape which may be adapted to the design of a particular seat cushion and seat frame. As shown in FIG. 1, the perimeter of the seat pan is bent to form peripheral walls which may, or may not, have a second horizontal portion associated therewith. A supportive cushioning elastic structure 25 comprising springs and straps, or any other suitable support members, extends across the opening in the seat pan 18 to provide support for the seat cushion 10.
The seat frame 16 and the seat pan 18 are fastened to one another in a vertically juxtaposed relationship. In this example the means for fastening the rigid seat support member and the seat pan 18 to one another are a plurality of threaded fasteners 24. The threaded fasteners do not extend through the uppermost surface 26 of the seat pan, but rather are attached to the seat pan in depressions located in the upper surface of the seat pan or attach to a lower horizontally extending portion of the seat pan. The upholstery 14 is a sheet material which overlies the seat cushion 10 and is secured to the seat pan 18. Examples of sheet materials used as upholstery are fabrics, vinyls and leathers.
Referring next to FIGS. 3 to 6, there are shown exploded, front elevation, side elevation and top views, respectively, of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention. Of course it is understood that the design of various structural components of a vehicle seat can vary from one make and model of vehicle to another, with the vehicle seat shown being merely exemplary of a vehicle seat that may be employed in the practice of the present invention. The present invention does, however, apply to seats in general and may be employed not only with vehicle seats but also any seat where it is desired to ascertain whether or not the seat is occupied and the weight of a seat occupant.
As in the prior art, the vehicle seat has a seat cushion 10 and a seat back 12. The seat back may have a head rest 13 associated therewith. The seat back may be pivotally attached to the remainder of the seat, as best seen in FIG. 5. As in the prior art the seat cushion 10 is made of a comfortable, supportive but compressible material, for example foam rubber. The seat frame 16 is substantially like the prior art seat frame described above with reference to FIG. 1.
The seat pan 18 which supports the seat cushion 10 is substantially like the seat pan described above with respect to FIG. 1 and is attached to the seat frame 16 using threaded fasteners 24 in substantially the same manner as described above. The upholstery 14, as in the prior art, is a sheet material overlying the seat cushion 10 and secured to the seat pan 18. An advantage of the seat occupant sensing system of the present invention is that this system may be retrofitted to a prior art vehicle seat.
A seat occupant sensing system of the present invention has a seat pan 18 with a rigid member 19 disposed vertically above the seat pan in a spaced apart vertically juxtaposed relationship with the seat pan. Referring next to FIGS. 7A and 7B there are shown perspective views of the top side and bottom side, respectively, of a frame 19 with sensors 20 mounted thereon. In the embodiment illustrated in FIGS. 7A and 7B the rigid member 19 is a frame which has a generally rectangular shape and a sensor 20 is located in the vicinity of each corner of the frame. The supportive cushioning elastic structure 25 comprising springs and straps, or any other suitable support members, which in the prior art extends across the opening in the seat pan 18 to provide support for the seat cushion 10 instead extends across the frame 19. This feature prevents the springs from contacting both the seat pan and the frame, therefore potentially transferring forces from the frame to the seat pan.
As shown in FIGS. 5, 6 and 8 the rigid member 19 underlies a portion of the seat cushion 10 and may be made of any suitable material such as steel or aluminum. In the embodiment shown, the frame 19 includes a plate 50 which is located to be complementary to the anti-submarining portion 51 of the seat pan 18. The anti-submarining portion of a seat pan restricts the tendency of a belted seat occupant to slide forward during a rapid deceleration of the vehicle.
At least two sensors 20 are interposed between the rigid member 19, or frame, and the seat pan 18 such that all of the force transferred from the rigid member to the seat pan is transferred via the sensors. The sensors sense the magnitude of the force transferred therethrough and send signals to a device (not shown) which processes the signals to determine the weight that the portion of the seat cushion which the rigid member 19 underlies is bearing. Each sensor 20 may be, for example, a strain gauge, a load cell or a variable resistance pressure sensor.
A working prototype of a vehicle seat equipped with an occupant sensing apparatus in accordance with the present invention employed four sensors which were Model 14 compression-only subminiature load cells purchased from Sensotec, Inc. of 1200 Chesapeake Avenue, Columbus, Ohio U.S.A. These sensors had a range of either 45.4 kilograms (100 pounds) or 113.5 kilograms (250 pounds) and a seat could be equipped with only one size sensor or a combination of sizes. For example, 113.5 kilogram sensors could be used towards the front of the seat and 45.4 kilogram sensors could be used towards the rear of the seat. The height of these sensors is 3.8 millimeters (0.15 inch). If desired, at least one of the sensors may be one type of sensor, while the other sensor(s) may be another type of sensor.
If the surface of the rigid member 19 which is proximal to a sensor 20 is not substantially flat, it is desirable with these commercially available sensors to place a shim of some sort between the sensor and the rigid member to improve the transfer of forces from the rigid member to the sensor. The installation of the seat occupant sensing system into the seat is preferably facilitated by securing the sensors in place on the rigid member (frame) and thereafter placing the resultant assembly in a vertically juxtaposed relationship with the seat pan, with the sensors resting on the vertically uppermost surface of the seat pan 18.
As shown in FIG. 10, which is an enlarged fragmentary view, at the location indicated in FIG. 8, of a sensor 20 located between the rigid member 19 and the seat pan 18, each sensor has a plurality of electrical leads 21,22 extending therefrom for communicating with a device (not shown) which processes the signals to determine the weight that the portion of the seat cushion which the rigid member underlies is bearing. The vertically spaced apart relationship of the rigid member 19 (frame) and the seat pan 18 is illustrated very well in FIG. 10. The distance that the rigid member (frame) is spaced apart from the seat pan 18 is the height of the sensor disposed therebetween.
As shown in FIG. 8, which is a cross-sectional side view, taken along line 8--8 of FIG. 4, the portion of the seat cushion 10 which the rigid member 19 underlies is preferably spaced apart from a rear edge of the seat cushion. This feature minimizes the sensing of forces which are transferred from the seat back to the seat pan 18 via the sensors. This is important in the instance where a person seated in the rear seat of an automobile leans against the back of the front seat and could influence the forces transferred to the seat pan. It has been demonstrated that the seat occupant sensing system of the present invention is capable of determining the presence and weight of a seat occupant with good accuracy.
The rigid member 19 and the seat pan 18 are at least partially retained in the vertically juxtaposed relationship by a tension member. In the embodiment shown in the drawings the tension member is a sheet material 14 overlying the seat cushion 10 and secured to the seat pan 18. The sheet material is commonly referred to as the seat cover or upholstery. As shown in FIG. 8 the perimeter of the sheet material may have clips or a deformable strip associated therewith which can clip onto or be bent around an edge of the seat pan.
Referring next to FIG. 9 there is shown a top view of a vehicle bench type seat equipped with an occupant sensing apparatus employing a rigid member 19 and sensors 20 in accordance with the present invention. If it is desired to determine the presence and size of an occupant of the passenger side of a front bench seat of a vehicle, the occupant sensing system of the present invention may be incorporated into only the passenger side of the bench seat as illustrated in FIG. 9.
Referring next to FIG. 11 there is shown a schematic view of an occupant sensing apparatus in accordance with the present invention. A signal from each sensor is passed through an amplifier to a device, such as a microprocessor which processes the signal, or signals, to determine the weight that the rigid seat pan member is bearing. Algorithms to translate a signal to a weight are well known and are used for example in electronic bathroom scales. The algorithm must take into account the weight of the seat cushion and the rigid seat pan member in determining the weight of the seat occupant. Of course if the weight of the seat occupant is determined to be zero, the seat is unoccupied.
There is a need in the field of inflatable vehicle occupant restraints, such as air bags, to determine if the occupant of the front passenger seat of a motor vehicle equipped with a front passengerside air bag is an infant in an infant seat or a small child weighing less than a preselected amount. This weight determining device, such as a microprocessor, determines the weight that the rigid seat pan is bearing and is preferably a controller which controls the activation of at least one safety device for an occupant of the seat based upon the occupant's weight. The controller controls, for example, the activation of an inflatable vehicle occupant restraint or a seat belt pretensioner. Additionally the controller may control the manner in which an activated safety device operates, for example controlling the speed at which an airbag is inflated or the amount of seat belt slack which is to be taken up by the pretensioner. Thus, the seat occupant sensing system disclosed herein may determine the presence or absence of an object or person on a seat cushion, and if present, the weight of the person or object on the seat cushion. Based upon these determinations, the device may activate one or more safety devices, and/or control the manner in which an activated safety device operates.
With some car seat designs a seat frame is not part of the structure of the seat. As shown in FIG. 12, a fiberglass tray 60 can be placed above the seat pan 16. The fiberglass tray 60 thus forms the seat frame and transmits substantially all the load imposed on the seat by the seat occupant onto sensors which measure the weight of the occupant. In this way the seat occupant sensing system of this invention can be employed with a wider range of car seats.
FIGS. 12-14 illustrate how the fiberglass tray 60 substitutes for the frame 19. The fiberglass tray 60 provides a lightweight rigid member which can receive the distributed load imposed by a seat occupant on the cushion 10 and concentrate the distributed load on four points where the sensors 20 can measure the imposed load. The tray 60 requires stiffness, and must be contoured so the seat remains comfortable to the occupant. At the same time the tray must be of relatively low cost and light weight is also a consideration.
An alternative embodiment seat occupant sensing apparatus 100 of this invention, shown in FIG. 15, employs a sensor 102, shown in FIG. 18, which is based on the Giant Magnetoresistive (GMR) effect. The sensor 102, as shown in FIGS. 15, 16 and 17 is positioned in a housing 104 which contains a spring 106 which supports a plunger 108. The plunger 108 contains a permanent magnet 110 which is held above the GMR sensor 102. A cap 112 retains the plunger 108 and the spring 106 within the housing 104. A button 114 overlies the plunger 108 and extends through an opening in the cap 112. A force transmitted to the button 114 moves the plunger 108 containing the magnet 110 downwardly towards the sensor 102.
The housing 104 and the sensor 102, together with the permanent magnet 110, the plunger 108, the button 114, and the retaining cap 112 form a force measuring sensor 116 which can be installed between a seat frame 118 and a seat pan 120. The seat pan 120, as shown in FIGS. 15 and 16, is slightly modified from the seat pan 18 shown in FIGS. 3 and 8. The seat pan 120 has bosses 122 which reinforce holes 124 formed in the seat pan. The holes 124 are sized to receive the housings 104 of the force measuring sensors 116. The retaining caps 112 support the measuring sensors 116 on the upper surface 126 of the seat pan 120. The seat frame 118 is positioned above the seat pan 120 and engages and is supported on the buttons 114 of four force measuring sensors 116.
The seat pan 120 is mounted to a seat frame 140 which in turn is mounted to the floor 142 of a car or other vehicle. In this way the seat pan 120 is connected to a vehicle (not shown).
The weight of the occupant resting on the seat cushion 128 is supported by the buttons 114 of the force measuring sensors 116. The plungers 108 positioned beneath the buttons 114 cause the deflection of the springs 106 which allow the permanent magnets 110 to move downwardly towards the GMR sensors 102. The amount of downward movement of the permanent magnets 110 is controlled by the spring constant of the springs 106. Thus by the simple expedient of choosing the spring constant of the springs 106, the amount of force required to fully depress the plunger 108 on a force measuring sensor 116 can be set.
The force measuring sensors 116 incorporate GMR sensors 102 which sense static magnetic fields. The sensors 102 do not directly support the measured load and have no physical engagement with any moving or load supporting structure. The GMR sensors 102 utilize an effect discovered in 1988, in which certain thin film devices are able to detect static magnetic fields. GMR sensors utilize resistors built up of thin magnetic film a few nanometers thick separated by equally thin nonmagnetic layers.
A decrease in resistance of between about 10 and 20 percent in the built-up resistors is observed when a magnetic field is applied. The physical explanation for the decrease in resistance is the spin dependence of electron scattering and the spin polarization of conduction electrons in ferromagnetic metals.
The extremely thin adjacent magnetic layers couple antiferromagnetically to each other so that the magnetic moments of each magnetic layer are aligned antiparallel to adjacent magnetic layers. Electrons, spin polarized in one magnetic layer, are likely to be scattered as they move between adjacent layers. Frequent scattering results in high resistance. An external magnetic field overcomes the antiferromagnetic coupling and produces parallel alignment of moments in adjacent ferromagnetic layers. This decreases scattering and thus device resistance.
Groups of four resistors based on the GMR technology are arranged in a Wheatstone bridge and two legs of the bridge are shielded from the applied magnetic fields. The other two legs are positioned between the magnetic shields 130 which are shown schematically in FIG. 18. The magnetic shields act as flux concentrators to produce a device of tailored sensitivity to a magnetic flux of a selected intensity. A standard voltage is supplied to the solid state device 132 and a voltage is read out of the device 132 which is predictably related or proportional to the magnetic field to which the device is exposed. The devices have an axis 134 of sensitivity which is produced by the orientation of the magnetic flux shields 130 as shown in FIG. 18.
GMR sensors are available from Nonvolatile Electronics Inc. of 11409 Valley View Rd., Eden Prairie, Minn. GMR sensors are small, highly sensitive devices which have exceptional temperature stability, deliver high signal levels and require very little power and cost less than many competitive devices. All these factors are important in devices used in automobile safety applications.
The force measuring sensors 116 are employed as part of a system for deploying an air bag and will typically be used with an amplifier and microprocessor as shown in FIG. 11. The micro processor will incorporate logic which analyzes data from crash detecting sensors and data indicating the presence and weight of an occupant in the front passenger seat of an automobile and other data which may be relevant from additional sensors and will deploy or not deploy an air bag based on logic and sensor inputs.
It should be understood that sensors which sense loads or displacement can be employed with the seat occupant sensing system of this invention.
It should also be understood that the coil spring shown in the force measuring sensors 116 may employ coils which are round in cross-section or flat and that the size of the cross-section together with the material and the material modulus will control the spring constant. Further, the spring employed in the force measuring sensor 116 could use other types of springs such as Belleville springs, or gas springs.
It should also be understood that the seat frame 140 may incorporate an adjustment mechanism which allows motion of the frame with respect to the car floor or allows motion of the seat pan 120 with respect to the frame 140.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims.
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An occupant weight sensing system has a seat pan which is rigidly mounted to a seat frame which attaches to a vehicle body. A seat cushion on which the occupant sits is positioned over the seat pan. A rigid frame is positioned above the seat pan and receives and supports the weight of the occupant. The rigid frame is supported on four sensors which in turn are mounted on the seat pan. The sensors collectively measure the weight supported by the rigid frame and thus determine the weight of the seat occupant. The sensors used to measure the weight of the seat occupant can be of two basic types. The first type is a load cell which experiences very little displacement and directly measures the imposed load. The second type of sensor employs a spring, the spring constant of which controls the amount of displacement for a given load. A Magnetoresistive Effect (GMR) displacement sensor measures the amount the spring is compressed.
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BACKGROUND OF THE INVENTION
This invention relates to devices for attenuating exhaust noise. More particularly, this invention relates to an attenuator member mounted within an exhaust pipe for changing exhaust fluid direction and reducing exhaust noise.
Engines such as internal combustion and gas turbine engines produce large quantities of exhaust gases which must be vented to atmosphere. These exhaust gases exit through exhaust pipes at high velocities and produce sound and noise at very high decibel (db) levels. These high noise levels can be injurious to the hearing of operators in the vicinity of the engines producing the noise.
With the advent of federal Occupational Health and Safety (OSHA) standards it has become mandatory to reduce noise levels to acceptable limits within the OSHA guidelines. Typically, current engine exhaust pipes direct exhaust gases straight out the pipe end or outlet. Exhaust gas velocity and temperature gradients just beyond the end of the exhaust pipe create velocity and sound distribution in the exhaust gases which causes sound to be diffracted radially outwardly of the pipe axis. Observers or operators laterally opposite the exhaust pipe are thus presented with high noise levels.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention includes an attenuator member or diffuser mounted within a flared exhaust pipe for directing sound toward the exhaust pipe axis and thus preventing it from moving radially outwardly where it can cause problems to laterally positioned operators. The attenuator member is mounted within an exhaust pipe having smaller diameter and a larger diameter end joined by an intermediate frustoconically shaped transition portion. The attenuator member is correspondingly frustoconically shaped and spaced from the frustoconically shaped transition portion.
The attenuator member is mounted to the exhaust pipe by a centrally disposed elongated rod attached thereto at one end and to a bracket formed by three plates having their planar surfaces within the exhaust gas stream and parallel to the exhaust pipe axis. In this manner exhaust gas flow is only minimally impeded.
The attenuator member thus described causes the exhaust gases passing therearound to diffuse and eddy so that noise is directed toward the exhaust pipe axis rather than radially away as with unattenuated exhaust pipes.
In an alternate embodiment of the invention, vents are added to the attenuator member to increase efficiency.
In a further alternate embodiment the exhaust pipe is combined with a muffler for additional sound control. The muffler forms a chamber around the exhaust pipe and a plurality of perforations in the pipe give access to the chamber from the pipe interior.
It is therefore the primary object of this invention to provide a means for reducing exhaust noise.
It is a further object to provide attenuation of exhaust pipe gas velocity.
It is a further object of this invention to provide an attenuator for an exhaust pipe for directing noise radially inwardly toward the pipe axis.
Further and other objects will become more readily apparent from a review of the following specification and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall isometric view of the exhaust noise reducing device of the instant invention;
FIG. 2 is a front elevational cross-section view of the same taken along lines II--II in FIG. 1;
FIG. 3 is a top plan view of the same taken along lines III--III in FIG. 1;
FIG. 4 is a view of the same similar to FIG. 2, and showing flow geometry;
FIG. 5 is a view similar to FIG. 4 of an alternate embodiment having vents and illustrating a different flow geometry;
FIG. 6 is a top plan view of the embodiment of FIG. 5;
FIG. 7 is a view taken along lines VII--VII in FIG. 5 and illustrating the shape of a single vent; and,
FIG. 8 is a front elevational cross-section view of an alternate embodiment in combination with a muffler.
DETAILED DESCRIPTION
Turning to FIG. 1, there is shown generally at 10 an exhaust pipe comprising a tubular inlet portion 12 having an open inlet 14 for admitting exhaust gas from, e.g., an internal combustion engine. The exhaust pipe has a frustoconical transition portion 16 leading to an outlet or exhaust portion 18 having an open outlet 20.
Within the flared outlet portion is an attenuator member or baffle 22. As best seen in FIGS. 2 and 3, attenuator member or baffle 22 has a circular forward or inlet end wall 24 and a frustoconically shaped side wall 28 joined to the inlet wall. Mounting means are provided in the form of an elongated rod 30 fitted in aperture 32 in inlet wall 24. An opposite end of rod 30 is fixed to a bracket 36 formed by three planar plate members, two of which are shown at 38,40. The plane of the plate members is set to be parallel to the axis defined by inlet portion 12 and thereby the exhaust gases carried therein so as to minimally impede flow thereof. The bracket 36 and the attenuator member 22 may be fixed to rod 30 by any convenient means, such as welding.
The baffle is mounted so that its side wall 28 is in spaced, parallel relation with respect to transition portion 16. In this manner, exhaust gases are desirably directed around the baffle and through outlet 20. The flow geometry of this baffle is illustrated in FIG. 4.
As a further refinement, an alternate embodiment is shown in FIGS. 5-7, having three equally spaced generally elongated, hollow vents defining walls 126 for admitting air flow from the ambient surrounds to be mixed with the exhaust gases. Walls 126 partially support the baffle and are interconnected between a pair of openings 125, 127 in the baffle and transition portion, respectively. In actual comparative tests between the FIGS. 1-4 and FIGS. 5-7 embodiments using an engine operation at 2200 RPM, at 160 BMEP, vacuum, a measure of performance, was measured at the muffler inlet. With vents of the shape shown in FIG. 7 having a semicircular lead portion of radius R and an elongated tail portion of length L having a cross-sectional area equal to the cross-sectional area of the main tubular inlet portion 112, the vacuum was approximately 4.55 in. Hg. as opposed to approximately 3 in. Hg. with 1200 CFM flow. Diffuser efficiency was approximately 43 percent with vents as opposed to approximately 55 percent without. Another difference was that the annular jet coalesced close to the muffler exit without vents (FIG. 4), but did not with vents (FIG. 5). This is considered to be advantageous from an acoustic standpoint. Velocity head measurements in the vents indicated that at 1200 CFM primary exhaust flow, the aspirated ventilation flow was about 20 percent of this value.
FIG. 8 shows a further alternate embodiment. With this embodiment a tubular muffler body 242 defining an annular muffler chamber 244 around inlet portion 212 is provided. A plurality of perforations or holes 246 is contained in inlet portion 212 which allows intercommunication between the interior of exhaust pipe portion 212 and chamber 244.
It is to be understood that the foregoing description is merely illustrative of a preferred embodiment of the invention, and that the scope of the invention is not to be limited thereto but is to be determined by the scope of the appended claims.
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An attenuator for reducing exhaust noise in engines is provided which includes an exhaust pipe having a flared outlet and a frustoconically shaped attenuator member mounted therein. In an alternate embodiment, vents are provided to increase efficiency. In a further alternate embodiment, the exhaust pipe is combined with a muffler.
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CROSS-REFERENCE TO RELATED CASES
The present application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/487,092; filed Jul. 14, 2003 and U.S. Provisional Ser. No. 60/498,626; filed Aug. 28, 2003, the disclosures of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates in general to injectors for dispensing fluids in fine sprays, and more particularly relates to fuel injectors for dispensing liquid fuel in fine sprays for ignition in gas turbine engines.
DESCRIPTION OF THE PRIOR ART
The art of producing sprays of liquid is extensive. Many injectors have a nozzle with a swirl chamber. One or more angled inlet slots direct the fluid to be sprayed into the swirl chamber. The inlet slots cause the fluid to create a vortex in the swirl chamber adjacent to a spray orifice. The fluid then exits through the spray orifice in a conical spray. Patents showing such injectors include U.S. Pat. Nos. 4,613,079 and 4,134,606.
In the combustion of fuels, a nozzle that provides a spray of fine droplets improves the efficiency of combustion and reduces the production of undesirable air pollutants. In some applications, it is desirable to have very low Flow Numbers and Flow Numbers that vary from location to location. The “Flow Number” relates the rate of fluid flow output to the applied inlet pressure. Flow Numbers that are less than 1.0 lb/hr.psi 0.5 , and even as small as 0.1 lb/hr.psi 0.5 , are desirable in some applications. This corresponds to swirl chambers less than 1.905 mm (0.075 inches); and exit orifices of less than 0.3048 mm (0.012 inches) diameter.
It is believed that for many years it was only possible to manufacture many of the openings and surfaces of small nozzles to create such low Flow Numbers by using relatively low volume machine tool and hand tool operations in connection with high magnification and examination techniques. This was a labor-intensive process with a high rejection or scrap rate.
One technique which has overcome this problem and produces spray nozzles having Flow Numbers as low as 0.1 lb/hr.psi 0.5 is described and illustrated in U.S. Pat. No. 5,435,884. In this patent, which is owned by the assignee of the present application, a nozzle having a small swirl chamber, exit orifice and feed slots is provided that produces a fine droplet spray. The swirl chamber, exit orifice and feed slots are formed by chemical etching the surfaces of one or more thin metal plates. The etching produces a nozzle with very streamlined geometries thereby resulting in significant reductions in pressure losses and enhanced spray performance. The chemical etching process is easily repeatable and highly accurate, and can produce multiple nozzles for individual or simultaneous use.
The nozzle shown and described in the '884 patent has many advantages over the prior art, mechanically-formed nozzles, and has received acceptance in the marketplace. The nozzle has design features that allow it to be integrated into an affordable multi-point fuel injection scheme. One particular application for such a nozzle is described in U.S. Pat. No. 6,550,696, also owned by the assignee of the present invention, where an integral air swirler, provided in one or more etched plates of the injector, is combined with the nozzle allowing the introduction of fuel sprays into an air flow. By premixing the fuel and air, a homogeneous fuel-air mixture is achieved, localized regions of near stoichiometric fuel-air mixtures are avoided, and a reduction in Nitrous Oxide (NOx) and Carbon Monoxide (CO) emissions can be realized.
The injector described in the '696 patent achieves some fundamental advantages, and has a plurality of nozzles arranged in a matrix across the surface of the injector, with the nozzles oriented to provide sprays of fuel in the axial (downstream) direction.
A similar arrangement is shown in U.S. Pat. No. 6,311,473, where the axial sprays are arranged in an annular configuration in a single plane, and outwardly bounded by an annular sheet of air, to avoid impinging on the downstream walls of the housing. Downstream radial air swirlers are also provided to facilitate vaporization of the fuel.
Certain applications require the use of radial, rather than axial-directed nozzles. Such an arrangement can provide some advantages. It is known to provide an injector comprising a plurality of plates with etched passages, where the plates have a T-shaped design, and which are then mechanically formed into a cylindrical, ring-shaped configuration, such as shown and described in U.S. Pat. No. 6,321,541, also owned by the assignee of the present invention. The fuel is dispensed radially inward (or outward) through nozzles spaced around the circumferences of the ring. In this application however, air swirlers are not disclosed, which again, can be useful in some application to achieve better overall combustion.
It is believed there is a demand for a fuel injector with a nozzle assembly having a cylindrical configuration for gas turbine applications with a plurality of nozzles that are compact and lightweight, and where each nozzle includes integral structure that allows the introduction of air (or another fluid) into or in conjunction with the fuel. It is further believed that there is a demand, particularly for gas turbine applications, for an injector with a feed ring that has a plurality of nozzles with a low Flow Number and integral air swirlers to reduce NOX and CO emissions, improve spray patternization, and provide a fuel spray that is well dispersed for efficient combustion.
SUMMARY OF THE INVENTION
The present invention provides a novel and unique fuel injector having a cylindrical configuration and a plurality of compact and lightweight nozzles that provide sprays of fine droplets of fuel, and includes integral structure that allows the introduction of air or other fluid into or in conjunction with the fuel. According to one application of the invention, the injector is useful for gas turbine applications and includes a feed ring with a plurality of nozzles spaced around the circumference of the ring, where each nozzle has a low Flow Number, and an integral air swirler that reduces NOX and CO emissions. The nozzles provide good spray patternization and the fuel spray is well dispersed for efficient combustion. In addition, the nozzles can be accurately and repeatably manufactured.
According to the present invention, the feed ring of the injector includes a plurality of thin, flat T-shaped plates of etchable material disposed in adjacent, surface-to-surface contact with one another. A plurality of nozzles are formed in a linear, evenly-spaced array along the head nozzle portion (transversely extending arms) of the plates. Each nozzle includes a metering assembly formed in one or more of the plates to provide a fine spray of fuel; and an integral swirler structure formed in one or more of the plates. The swirler structure allows the introduction of air or other fluid into or in conjunction with the fuel spray.
The metering assembly preferably includes a bowl-shaped swirl chamber shaped by etching at least one of the plates. Chemical etching, electro-mechanical etching or other appropriate etching technique can be used to form the swirl chamber. A spray orifice, also preferably formed by etching, is in fluid communication with the center of the swirl chamber. At least one feed slot, also preferably formed by etching, is in fluid communication with the swirl chamber and extends in tangential (non-radial) relation thereto. Fuel directed through the feed slot(s) moves in a vortex motion toward the center of the swirl chamber, and then exits the spray orifice in the conical spray of fine droplets.
The swirler structure preferably provides a swirling component of motion to the fuel spray. The swirler structure preferably includes a cylindrical swirler passage, also shaped by etching through at least one of the other plates. The cylindrical swirler passage is located in co-axial relation to the spray orifice of the metering set, such that the fuel from the spray orifice passes through the swirler passage. At least one air feed slot, also preferably formed by etching, is provided in fluid communication with the swirler passage and extends in tangential (non-radial) relation thereto. The second fluid (air) is provided through the feed slot and moves in a swirling motion in the swirler passage. The second fluid imparts a swirling component of motion to the fuel as the fuel passes through the swirler passage. The feed slot(s) can be oriented to provide fluid streams in the same direction (co-rotating), or in opposite directions (counter-rotating). In some applications the air feed slots could be purely radial, such that the air is not caused to swirl.
Supply passages for the second fluid extend through the plates of the metering set and the swirler structure to the feed slots in each plate of the swirler structure.
The plates of the feed ring are fastened together (such as by bonding), and are mechanically formed such that the arms of the ring define a cylinder, with the nozzles preferably oriented to dispense fuel radially inward into the annulus of the injector, although the strip could also be configured to dispense fuel radially outward merely by bending the strip in the opposite direction (or forming the nozzles on the opposite side of the strip).
The feed ring is supported within a barrel-shaped housing, which preferably includes an upstream housing portion and a downstream housing portion, each of which has a chamber portion which when the housing portions are assembled together, define a ring chamber for the feed ring. The downstream housing portion includes an inner annular flange that radially inwardly supports the feed ring, and a series of ports to allow fuel to pass from the ring radially inward toward the central axis of the housing. The inner housing flange also includes a venturi configuration, that is, an annular geometry projecting radially-inward toward the central axis of the housing, and causing fuel sprayed out through the ports to remain separated from the downstream walls of the housing to facilitate efficient combustion. The ports are preferably formed along about the axial midpoint of the venturi configuration.
Injectors constructed according to the present invention have a cylindrical configuration that is lightweight and compact, and can be used to introduce a second fluid into a fuel spray. In gas turbine applications, the injector can be used to introduce a swirling air flow into a fuel spray to enhance mixing and reduce NOX and CO emissions from the gas turbine engine. The swirling flow also enhances flame stability by generating toroidal recirculation zones that bring combustion products back towards the fuel injection apparatus thereby resulting in a sustained combustion and a stable flame. The swirling flow also provides good spray patternization and the fuel spray is well-dispersed for efficient combustion.
Further features of the present invention will become apparent to those skilled in the art upon reviewing the following specification and attached drawings
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section side view of a combustion system for a gas turbine engine, with a fuel injector assembly constructed according to the present invention;
FIG. 2 is a cross-sectional end view of the injector assembly, taken substantially along the plane described by the lines 2 — 2 in FIG. 1 ;
FIG. 3 is a cross-sectional side view of the injector assembly of FIG. 2 with the swirler removed;
FIG. 4 is an elevated perspective view of the injector for the injector assembly of FIG. 3 ;
FIG. 5 is an enlarged cross-sectional side view of a portion of the injector assembly of FIG. 3 ;
FIG. 6A is an elevated perspective view of the manifold plate for the injector of FIG. 4 ;
FIG. 6B is an elevated plan view of the manifold plate after forming;
FIG. 7A is an elevated perspective view of the distribution plate for the injector;
FIG. 7B is an elevated plan view of the distribution plate after forming;
FIG. 8A is an elevated perspective view of the spin plate for the injector;
FIG. 8B is an elevated plan view of the spin plate after forming;
FIG. 9A is an elevated perspective view of the orifice plate for the injector;
FIG. 9B is an elevated plan view of the orifice plate after forming;
FIG. 10A is an elevated perspective view of the heat shield plate for the injector;
FIG. 10B is an elevated plan view of the heat shield plate after forming;
FIG. 11A is an elevated perspective view of the air swirler plate for the injector; and
FIG. 11B is an elevated plan view of the air swirler plate after forming.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and initially to FIG. 1 , a portion of a combustion system for a turbine engine is indicated generally at 20 . The system includes a combustion chamber 22 ; and a fuel injector assembly, indicated generally at 24 , mounted to the upstream end wall 25 of the combustion chamber. The fuel injector assembly 24 atomizes and directs fuel into the combustion chamber 22 for burning, as should be well known to those skilled in the art. Combustion chamber 22 can be any useful type of combustion chamber, such as a combustion chamber for industrial power generation equipment; however, the present invention is believed useful for combustion chambers for other types of combustion applications, such as in ground vehicles, where a fine dispersion of fuel droplets of two fluids (e.g., a liquid fuel and air) is desirable. One particularly useful application for the combustion system of the present invention is in the premixer described in U.S. Pat. No. 6,311,473, owned by the assignee of the present invention and which is incorporated herein by reference. In any case, the combustion chamber will not be described herein for sake of brevity, with the exception that as should be known to those skilled in the art, air is compressed, mixed with the fuel, and directed into the combustion chamber and ignited, so that the expanding gases of combustion can rapidly move across and thus rotate turbine blades (not shown). While a single injector assembly is shown in FIG. 1 , it should be appreciated that multiple injector assemblies could be used mounted to the combustor.
The fuel injector assembly 24 includes a barrel-shaped housing, indicated generally at 30 ; an another air swirler, indicated generally at 32 ; and a fuel injector, indicated generally at 36 . The air swirler 32 preferably comprises an axial swirler having a series of helical vanes 38 for directing air in a swirling manner into the upstream end of the injector assembly. A center body 39 is centrally located in the housing and surrounded by swirler 32 . Center body 39 comprises a pilot nozzle for introducing natural gas or liquid fuel into the fuel injector assembly. The pilot nozzle is useful to stabilize the flow when the fuel injector assembly is used in a lean premix mode, and may not be necessary in every application. In any event, the type of pilot nozzle useful for the particular application can be determined by those skilled in the art.
Referring to FIGS. 2–5 , the fuel injector 36 comprises a feed ring, indicated generally at 67 having an inlet port 68 . The feed ring is preferably formed from relatively thin (e.g., 0.005–0.090 inches thick), flat plates 76 – 81 which are located in adjacent, surface-to-surface contact with each other. As can be seen in FIGS. 6A–11A , each of the plates 76 – 81 preferably has a T-shaped configuration, and is formed in one piece from a metal sheet of an appropriate material such as INCONEL 600. Each plate can be formed in the required configuration (such as the illustrated T-shape configuration) by durable etching, stamping or die-cutting. While six plates are illustrated and described, it is of course possible that a greater or lesser number of plates could be provided, and that the shape of the individual plates may be other than as illustrated, for example, they could simply be elongated flat strips (i.e., not “T” shaped).
As shown in FIGS. 6A and 6B , the first, manifold plate 76 , has a short feed portion 80 and an elongated head nozzle portion 82 , extending substantially perpendicular to the feed portion 80 . A fuel feed passage is formed on an inner surface 83 of the plate. The feed passage includes an enlarged cavity in the feed portion 80 ; and a pair of thin channels or grooves 85 , 86 , which are fluidly connected to the cavity 84 , and extend outwardly centrally along each arm of the head nozzle portion in parallel, spaced relation, along substantially the entire length of the opposing arms. The distal ends of the respective channels 85 , 86 can be fluidly interconnected.
Slotted through-passages as at 88 are provided through the head nozzle portion of plate 76 , and extend along the peripheral edge, to allow the passage of air, as will be described below. The number, spacing and dimension of the passages 88 can vary, as will also be described below.
A series of elongated slots as at 89 are interposed between the fuel channels 85 , 86 and the through passages 88 , and define stagnant air gaps for thermal protection. The number, spacing and dimension of slots 89 can also vary, as will be described below.
The cavity, grooves, passages and slots in the manifold plate 76 are preferably formed when the plate is flat ( FIG. 6A ). The cavity, grooves, passages and slots can be formed in any appropriate manner, and it is preferred that they be formed by etching, such as chemical etching, electro-mechanical etching or other appropriate etching technique. The etching of such plates should be known to those skilled in the art, and is described for example in Simmons, U.S. Pat. No. 5,435,884, which is hereby incorporated by reference. The etching of the plates allows the forming of very fine, well-defined and complex openings and passages, which provides a hydraulically natural shape for efficient fluid flow.
Referring now to FIGS. 7A , 7 B, the second, distribution plate 77 is similarly constructed and includes a short feed portion 90 and an elongated head nozzle portion 92 , extending substantially perpendicular to the feed portion 90 . An inlet passage 93 is formed centrally through feed portion 90 . Pairs of spaced-apart fuel distribution through-slots, as at 94 , are formed along the length of the arms of the head nozzle portion 92 .
Slotted through-passages as at 98 are provided through the distribution plate 77 , and extend along the peripheral edge, to allow the passage of air, in the same manner as passages 88 in manifold plate 76 .
A series of elongated slots as at 99 are interposed between the fuel slots 94 and the through passages 98 , and define stagnant air gaps for thermal protection in the same manner as slots 89 in manifold plate 76 .
The passages and slots in the distribution plate 77 are also preferably formed when manifold plate 76 is flat, in the same manner as described above. When the distribution plate 77 is located adjacent, surface-to-surface relation to manifold plate 76 , inlet passage 93 in plate 77 is fluidly aligned and communicates with cavity 84 in adjacent manifold plate 76 . Likewise, each fuel distribution slot 94 in plate 77 is fluidly aligned and communicates with a respective fuel channel 85 , 86 in the adjacent manifold plate 76 . The through-passages 98 and slots 99 in distribution plate 77 are likewise fluidly aligned and communicate with respective passages 88 and slots 89 in the adjacent manifold plate 76 (see FIG. 4 ).
Referring now to FIGS. 8A and 8B , third, spin plate 78 is similarly constructed and includes a short feed portion 100 and an elongated head nozzle portion 102 , extending substantially perpendicular to the feed portion 100 . An inlet passage 103 is formed centrally through feed portion 100 . Spin chambers as at 104 with non-radial feed slots as at 105 , are formed along the length of the arms of the head nozzle portion 102 , and extend through the plate from one side to the other.
Slotted through-passages as at 108 are provided through the spin plate 78 , and extend along the peripheral edge, to allow the passage of air, in the same manner as passages 98 in distribution plate 77 .
A series of elongated slots as at 109 are interposed between the swirl chambers 104 and the through passages 108 , and also between adjacent swirl chambers, and define stagnant air gaps for thermal protection in the same manner as slots 99 in distribution plate 77 .
The passages and slots in spin plate 78 are also preferably formed when the spin plate 78 is flat, in the same manner as described above. The spin plate 78 is located in adjacent, surface-to-surface relation with distribution plate 77 . When so located, inlet passage 103 in plate 78 is fluidly aligned and communicates with inlet passage 93 in adjacent distribution plate 77 . Each feed slot 105 is fluidly aligned and communicates with the distal end of a respective one of the fuel distribution slots 94 in the adjacent distribution plate 77 . The through-passages 108 and slots 109 in spin plate 78 are likewise fluidly aligned and communicate with respective passages 98 and slots 99 in the adjacent distribution plate 77 (see FIG. 4 ).
Referring now to FIGS. 9A and 9B , fourth, orifice plate 79 is similarly constructed and includes a short feed portion 110 and an elongated head nozzle portion 112 , extending substantially perpendicular to the feed portion 110 . An inlet passage 113 is formed centrally through feed portion 110 . Small circular orifices as at 115 are formed along the length of the arms of the head nozzle portion 112 , and extend through the plate from one side to the other.
Slotted through-passages as at 118 are provided through the orifice plate 79 , and extend along the peripheral edge, to allow the passage of air, in the same manner as passages 108 in spin plate 78 .
A series of elongated slots as at 119 are interposed between the orifices 115 and the through passages 118 , and also between adjacent orifices, and define stagnant air gaps for thermal protection in the same manner as slots 109 in spin plate 78 .
The orifices, passages and slots in orifice plate 79 are preferably formed when orifice plate 79 is flat, in the same manner as described above. The orifice plate is located in adjacent, surface-to-surface relation with spin plate 78 . When so located, inlet passage 113 in plate 79 is fluidly aligned and communicates with inlet passage 103 in adjacent spin plate 78 . Each orifice 115 is centrally, fluidly aligned and communicates with a respective spin chamber 104 in the adjacent spin plate 78 . The through-passages 118 and slots 119 in orifice plate 79 are likewise fluidly aligned and communicate with respective passages 108 and slots 109 in the adjacent spin plate 78 (see FIG. 4 ).
Referring now to FIGS. 10A and 10B , fifth, heat shield plate 80 is similarly constructed and includes a short feed portion 120 and an elongated head nozzle portion 122 , extending substantially perpendicular to the feed portion 120 . An inlet passage 123 is formed centrally through feed portion 120 . Circular orifices as at 125 , of a diameter larger than orifices 115 in orifice plate 79 , are formed along the arms of the head nozzle portion 122 , and extend through the plate from one side to the other.
Slotted through-passages as at 128 are provided through the heat shield plate 80 , and extend along the peripheral edge, to allow the passage of air, in the same manner as passages 118 in orifice plate 79 .
A series of elongated channels or grooves as at 129 are formed on an outer surface 130 of the heat shield plate, and are interposed between the orifices 125 and the through passages 128 , and also between adjacent orifices, and define stagnant air gaps for thermal protection in the same manner as slots 119 in orifice plate 79 .
The orifices, passages and channels in heat shield plate 80 are preferably formed when heat shield plate 80 is flat, in the same manner as described above. The heat shield plate is located in adjacent, surface-to-surface contact with orifice plate 79 . When so located, inlet passage 123 is fluidly aligned and communicates with inlet passage 113 in adjacent orifice plate 79 . Each orifice 125 is co-axially, fluidly aligned with a respective orifice 115 in the adjacent orifice plate 79 . The through passages 128 and channels 129 in heat shield plate 80 are likewise fluidly aligned and communicate with respective passages 118 and slots 119 in the adjacent orifice plate 79 (see FIG. 4 ).
Referring now to FIGS. 11A and 11B , sixth, air swirler plate 81 is similarly constructed and includes a short feed portion 130 and an elongated head nozzle portion 132 , extending substantially perpendicular to the feed portion 130 . An inlet passage 133 is formed centrally through feed portion 130 . Circular orifices as at 135 , of a diameter larger than orifices 125 in heat shield plate 80 , are formed along the length of the arms of the head nozzle portion 132 , and extend through the plate from one side to the other.
Slotted channels or grooves as at 138 are provided along the outer surface 139 of air swirler plate 81 , and extend along the peripheral edge, to direct the passage of air across the plate. Non-radial channels or grooves as at 141 fluidly interconnect with channels 138 , and direct the air into orifices 135 .
A series of channels as at 141 are also formed on the outer surface of the air swirler plate, and are interposed between the orifices 135 and channels 138 and 140 , and also between adjacent orifices, and define stagnant air gaps for thermal protection.
The orifices and channels in the air swirler plate 81 are preferably formed when air swirler plate 81 is flat, in the same manner as described above. The air swirler plate is located in adjacent, surface-to-surface contact with heat shield plate 80 . When so located, inlet passage 133 is fluidly aligned and communicates with inlet passage 123 in adjacent heat shield plate 80 . Each orifice 135 is co-axially, fluidly aligned with a respective orifice 125 in the adjacent heat shield plate 80 . The channels 138 in air swirler plate 81 are likewise fluidly aligned with respective passages 128 in the adjacent heat shield plate 80 (see FIG. 4 ).
After the plates are appropriately formed and stacked as above, the plates 76 – 81 are fixed together in an appropriate manner to form the complete feed ring 67 . It is preferred that the plates are fixed together in surface-to-surface contact with a bonding process such as brazing or diffusion bonding. Such bonding processes are well-know to those skilled in the art, and provide a secure connection between the various plates. A more detailed discussion of such bonding can be found, for example, in U.S. Pat. No. 5,484,977; U.S. Pat. No. 5,479,705; and U.S. Pat. No. 5,038,857, among others.
The head nozzle portions of all the plates are then mechanically formed (bent) into an appropriate configuration. As shown in FIG. 4 , the head portions are illustrated as being formed into a cylindrical or annular configuration, such that manifold plate 76 is the radially outermost plate, and air swirler plate 81 is the radially innermost plate. The bending of the plates can be accomplished using appropriate equipment, for example, a cylindrical mandrel or other appropriately-shaped tool. A gap is preferably provided between the opposing, distal ends of the plates to allow for some thermal growth, however they could also be joined together by an appropriated process such as brazing or welding to form a continuously cylindrical nozzle. It should be noted that the plates could also be formed into shapes other than cylindrical, or even provided without forming, in appropriate applications.
The feed portions of the plates are then collectively bent at an angle, and preferably substantially normal to the plates, to create the inlet port 68 .
Referring now to FIGS. 3 and 5 , the injector 36 , after it is assembled as above, is captured and supported within a ring chamber 140 formed in the barrel shaped housing 30 . Housing 30 comprises an upstream annular housing portion 142 and a downstream annular housing portion 144 , each of which includes a portion of the chamber, and which fit closely together to form the entire chamber. Upstream housing portion 142 includes an outer annular flange 146 which outwardly supports the feed ring 67 , and which includes a series of slotted feed passages 150 which are fluidly aligned with and communicate with the air passages 88 in the manifold plate 76 (see FIG. 4 ) to direct air into the feed strip.
The downstream housing portion 144 also includes an annular flange 152 , supporting the radially inner side of the feed ring. A series of openings 154 are formed around flange 152 , having a dimension larger than the openings 135 in air swirler plate 81 , and which are co-axially aligned therewith (see FIG. 4 ).
The housing portions 142 , 144 are also fixed together in an appropriate manner after the plates are located in the ring chamber, such as by welding or brazing.
When the injector is supported within the housing as described above, a series of nozzles as at 200 , are defined around the circumference of the injector assembly (see FIG. 2 ). The nozzles are preferably evenly-spaced around the injector assembly, and the flow channels, slots and passages in each nozzle direct fuel from the feed stem 64 into chamber 84 in plate 76 , where the fuel is directed (circumferentially) out through channels 85 , 86 in plate 76 ( FIG. 6A ), and then radially inward through distribution slots 94 in plate 77 ( FIG. 7A ). The distribution slots 77 direct the fuel into feed slots 105 in plate 78 ( FIG. 8A ) where the fuel then is directed into swirl chamber 104 in a swirling manner. The fuel then passes radially inward through orifice 115 in the adjacent plate 79 ( FIG. 9A ) and is delivered in a conical spray through orifices 125 , 135 in adjacent plates 80 , 81 ( FIGS. 10A , 11 A). The foregoing defines the metering structure of the injector that meters fuel through the injector.
Air is provided through inlet passages 150 in housing 66 , where the air passes through slots 88 in plate 76 ( FIG. 6A ), slots 98 in plate 77 ( FIG. 7A ), slots 108 in plate 78 ( FIG. 8A ), slots 118 in plate 79 ( FIG. 9A ), and slots 128 in plate 80 ( FIG. 10A ), where the air is then directed through channels 139 into non-radial feed channels 140 and into the fuel spray in a swirling manner, where the swirling air imparts a swirling component of motion to the fuel spray to facilitate atomization and uniform mixing. The above structure defines the integral air swirler aspect of the injector.
The swirling fuel sprays then pass through openings 154 in the downstream housing portion, and into the air stream passing axially through the housing.
While only a single air swirler plate is shown, it is of course possible that multiple plates could be provided, each providing separate levels of swirling air flows to add further components of swirl to the fuel spray. The number, spacing and dimensions of the air passages can also vary depending on the desired air flow to be imported to the fuel sprays. The air passages could also be configured to provide simply axial air flows, so that the air flow would not be swirling. While not as preferred as a swirling air flow, such a configuration may be appropriate in certain applications to provide a sufficiently atomized spray. The number, spacing and dimensions of each nozzle could likewise vary depending on the particular application.
The air flow through the plates provides thermal protection for the nozzles. The stagnant air gaps in the interconnecting passages 89 in plate 77 ( FIG. 6A ); passages 99 in plate 78 ( FIG. 7A ); passages 109 in plate 79 ( FIG. 8A ); passages 109 in plate 78 ( FIG. 9 a ); and channels 129 in plate 80 ( FIG. 10B ) likewise provide thermal protection for the nozzles.
As should be appreciated, the spray nozzles 200 are provided around the radially-inner surface of the injector assembly in the illustrated embodiment to provide sprays of fuel radially-inward toward the central axis of the assembly. However, by appropriate routing of the fuel passages between the plates, or bending the plates in the opposite direction, the spray nozzles could likewise be formed in the radially-outer surface to direct fuel radially outward from the injector assembly.
As apparent in FIG. 4 , inlet port 68 comprises a tab or flange which is defined when the plates are interfitted together. The inlet port 68 provides a fuel inlet connection to the fuel stem 64 . The inlet port 68 includes aligned and fluidly-connected opening 293 in plate 77 ( FIG. 7B ), opening 103 in plate 78 ( FIG. 8B ), opening 113 in plate 79 ( FIG. 9B ), opening 123 in plate 80 ( FIG. 10B ) and opening 133 in plate 81 ( FIG. 11B ). Port 68 is located in abutting relation to the downstream surface of an annular, radially-enlarged flange 212 of upstream housing portion 142 . A passage 214 is provided through flange 212 from a front nipple 216 , and fluidly interconnects with opening 133 in plate 81 . Nipple 216 is connected to an appropriate source of fuel (not shown).
The inner annular flange 152 of the downstream housing portion preferably has a venturi geometry to facilitate the flow of fuel and air through the nozzle assembly. As shown in FIGS. 3 and 5 , the venturi configuration preferably comprises a radially-inward projecting geometry along the inside surface of one or both housing portions, which causes the fluid (air) flowing therepast to accelerate and converge toward the central axis of the housing. Upon introduction of the fuel through the nozzles, in a radially-inward manner, the accelerated air and venturi configuration cause the sprays to be redirected axially downstream through the housing, past the downstream lip of the downstream housing portion 144 . The venturi geometry of the housing substantially prevents the fuel from wetting the walls of the housing, downstream of the venturi, and thereby detrimentally effecting the atomized sprays. Rather, the sprays somewhat converge toward the central axis of the housing, and then pass downstream from the housing in a fully atomized and well-dispersed spray.
It is preferred that the nozzles 200 are located at the axial midpoint of the venturi geometry, however, it is believed they could also be located anywhere from the beginning to the end point of the venturi geometry and have some beneficial effect on the distribution of fuel.
As should be appreciated, swirling air is provided downstream through the housing by the axial swirler 32 , and directed past the nozzles. The swirling air flow impacts the fuel sprays along the venturi geometry; while air is also directed into inlet passages 150 ( FIG. 5 ) and then internally of each nozzle to provide a swirl component of motion to each spray. When the swirling fuel spray passes through each nozzle 200 , the fuel is impacted by the air passing downstream through the housing. The fuel/air mixture then passes out through the housing for burning in the combustion chamber.
If a pilot nozzle 39 is used, the fuel flow through the pilot and through nozzles 200 can be modulated to enhance combustion stability.
Again, while a single injector configuration is shown, such a structure is only for exemplary purposes, and it is possible that multiple injectors could be provided; and each injector could have more or fewer nozzles than illustrated, depending upon the particular application. Likewise, while a radially outer spray from the injector is shown, the spray could likewise be radially inner, or even axially from the end of the nozzle.
While nozzles 200 are pressure swirl atomizers for providing a hollow conical air atomized fuel spray, it should be appreciated that other nozzle designs could alternatively (or in addition) be used with the present invention to provide other spray geometries, such as plain jet, solid cone, flat spray, etc. Also, while identical round spray orifices 115 are shown in fuel swirler plate 79 ( FIG. 9A ), it should be appreciated that the dimensions and geometries of the orifices may vary across the plate, to tailor the fuel spray volume to a particular application. This can be easily accomplished by the aforementioned etching process.
It has been found that the air enhances mixing and reduces NOX and CO emissions from the gas turbine engine, and reduces flame blowout. The metering set and integral swirler structure also provide good spray patternization and the spray is well-dispersed for efficient combustion. The nozzles can also be accurately and repeatably manufactured.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular form described as it is to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the scope and spirit of the invention as set forth in the appended claims.
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An injector assembly includes a barrel-shaped housing and an injector, the injector including a feed ring formed of multiple, etched, T-shaped plates. A plurality of nozzles are arranged in an evenly-spaced array around the injector and direct fluid radially inward into the central annulus of the injector assembly. The injector includes an air inlet port with an internal feed passage fluidly connected to swirl chambers and exit orifices to provide individual sprays of fuel from the nozzles. Integral air swirlers impart a swirling component of motion to the fuel sprays. A venturi configuration is provided by the housing. The nozzles are provided along the venturi configuration, which maintains fluid separation from the walls of the housing downstream from the venturi.
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FIELD OF THE INVENTION
[0001] This invention relates to the field of semiconductor light emitting devices, and in particular to techniques for improving extraction efficiency and providing a more uniform current distribution across the light emitting region of the device.
BACKGROUND OF THE INVENTION
[0002] The substantial increase in demand for semiconductor light emitting devices, and the corresponding increase in competition to satisfy demand has caused manufacturers to seek techniques that will reduce costs or improve performance. Of particular note, techniques that improve the efficiency or quality of the emitted light may serve to distinguish one competitor's product from the others.
[0003] FIG. 1 illustrates an example prior art Thin Film Flip Chip (TFFC) InGaN Light Emitting Device (LED), such as disclosed in U.S. Pat. No. 6,828,596, “CONTACTING SCHEME FOR LARGE AND SMALL AREA SEMICONDUCTOR LIGHT EMITTING FLIp-CHIP DEVICES”, issued to Daniel A. Steigerwald, Jerome C. Bhat, and Michael J. Ludowise, and incorporated by reference herein.
[0004] In this example device, a light emitting layer 120 is formed between an n-layer 110 and a p-layer 130 . An external power source (not illustrated) provides power to the device via connections to pads 160 and 170 . The p-pad 160 is coupled to the p-layer 130 via a p-contact 140 , through an optional guard layer 150 that inhibits migration of the p-contact material. The n-contact layer 170 is coupled directly to the n-layer 110 in this example. A boundary layer 180 isolates the n-contact layer 170 and n-layer 110 from the p-layer 130 and p-contact 140 .
[0005] The p-contact 140 is provided over a large area to facilitate a uniform distribution of current through the p-layer 130 , which has a relatively higher resistance to current flow. The n-layer 110 does not exhibit a high resistance, and thus the n-contact covers a smaller area, which may be 10% or less of the device area. The p-contact 140 is preferably highly reflective to reflect the light toward the top, emitting surface of the light emitting device. Silver is commonly used as the p-contact 140 . The n-contact layer is also reflective and metals such as Aluminum are preferred. The guard layer 150 may be metallic, but is only partially reflective as a suitable highly reflective metal has not yet been found for this application. This partially reflective guard sheet fills the area adjacent to the p-contact, resulting in higher optical loss at the p-contact periphery.
[0006] The inventors have recognized that the light generated within about 15 microns of the periphery of the p-contact may, with high probability, enter the guard layer area 150 and suffer optical absorption before having a chance to exit the device. Therefore, current injected at the edge of the p-contact will exhibit a lower external quantum efficiency than current injected at the center area of the p-contact.
[0007] Despite the greater optical loss of the edges and corners of the device, the inventors have also noticed that more emitted light is produced at the periphery and in the corners than at the center of the device, because the voltage drop associated with the lateral flow of current through the n-contact layer, combined with the exponential dependence of vertical current flow upon junction voltage, provides a significantly higher current density at the edges and in the corners of the device. These relatively high injection currents create a slight halo-effect, with bright areas in the corners of the device.
[0008] In addition to potentially introducing optical anomolies, such a non-uniform current injection pattern is inefficient, as the internal quantum efficiency is lower for higher current densities. The ‘over-emitting’ portions, particularly the corners, of the light emitting device will also be ‘hot-spots’ that draw more current in the device, which have been observed to lead to premature failure of devices operated at high current.
SUMMARY OF THE INVENTION
[0009] It would be advantageous to distance the light emission regions away from the partially reflective guard layer and to further improve the uniformity of the injected current density light emissions across the surface of the active layer.
[0010] To better address these concerns and others, in an embodiment of this invention, the current distribution across the p-layer of a semiconductor device is modified by purposely inhibiting current flow through the p-layer in regions adjacent to the guardsheet, without reducing the optical reflectivity of any part of the device. This current flow may be inhibited by increasing the resistance of the p-layer that is coupled to the p-contact along the edges and in the corners of contact area. In an example embodiment, the high-resistance region is produced by a shallow dose of hydrogen-ion (H+) implant after the p-contact is created. Similarly, a resistive coating may be applied in select regions between the p-contact and the p-layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention is explained in further detail, and by way of example, with reference to the accompanying drawings wherein:
[0012] FIG. 1 illustrates an example prior-art light emitting device.
[0013] FIG. 2 illustrates current distribution in the example light emitting device.
[0014] FIGS. 3A-3B illustrate an example light emitting device with a p-contact that includes a high resistance region and a low resistance region to improve current distribution.
[0015] FIG. 3C illustrates an alternative to FIG. 3A .
[0016] Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions. The drawings are included for illustrative purposes and are not intended to limit the scope of the invention.
DETAILED DESCRIPTION
[0017] In the following description, for purposes of explanation rather than limitation, specific details are set forth such as the particular architecture, interfaces, techniques, etc., in order to provide a thorough understanding of the concepts of the invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments, which depart from these specific details. In like manner, the text of this description is directed to the example embodiments as illustrated in the Figures, and is not intended to limit the claimed invention beyond the limits expressly included in the claims. For purposes of simplicity and clarity, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
[0018] This invention is presented in the context of the example prior art device of FIG. 1 , for ease of illustration and understanding. One of skill in the art will recognize, however, that some or all of the principles of this invention may be applicable to a variety of different LED structures, or any structures that would benefit from a reduction in optical loss created by an absorbing region adjacent to a low loss current injection region.
[0019] As noted above, the light emitting device of FIG. 1 , the structure of which is repeated in FIGS. 2 and 3 , includes a highly reflective, large area p-contact 140 that provides for a more uniform distribution of current through the p-layer 130 . The contact between the n-layer 110 and the n-pad 170 is along the perimeter of the n-layer 110 . A boundary layer 180 separates the n-type elements 110 , 180 from the p-type elements 130 , 140 , 150 .
[0020] As illustrated in FIG. 2 , when connected to an external source via the n-pad 170 and p-pad 160 , the electron current 200 from the n-pad 170 spreads laterally through the n-layer 110 , crossing the boundary layer 180 and continuing down toward the p-contact 140 and the p-pad 160 . Because the current distribution across the n-layer 110 is not perfectly uniform, and because distance from the perimeter of the p-contact 140 and the source of the current 200 is shorter than the distance from the center of the p-contact 140 , the current flow 200 a to the perimeter of the p-contact 140 will be greater than the current flow 200 b to the center of the p-contact 140 . Depending upon geometry (corner vs. edge), n-GaN sheet resistance (thickness and doping), and operating conditions (current, temperature), a substantial fraction 200 a of the current injection 200 may be concentrated near the boundary of the p-contact 140 . Accordingly, the current injection through the p-n junction of active layer 120 will be larger around the periphery of the active layer 120 , creating a higher emission of light at the periphery.
[0021] In addition to potentially objectionable optical effects caused by this non-uniform light emission, this non-uniformity potentially reduces the overall light extraction efficiency, because the higher light emission occurs in regions where the optical losses are greatest. At the center of the light emitting active layer 120 , most of the emitted light will eventually exit the top surface of the light emitting device, either directly, or via reflections from the p-contact layer 140 . Light that is emitted from the center of the active layer 120 at severe angles (side-light) relative to the top surface will have a greater likelihood of exiting the top surface of the device than such light from other regions, because, from the center, there is less likelihood of encountering a light absorbing feature, such as the boundary layer 180 , before exiting the top surface. Conversely, along the perimeter of the active layer 120 , the likelihood of encountering the boundary layer 180 is significantly higher, with a corresponding increase in optical loss.
[0022] In addition to the optical problems associated with the non-uniform current flow, the larger current flow 200 a creates a “hot spot” that lowers the bandgap and draws even more current, resulting in the creation of failure prone areas in the device.
[0023] Additionally, the uneven current injection into the light emitting region also reduces the overall chip internal quantum efficiency (IQE; a ratio of the number of photons emitted per injected electron), because the IQE decreases as the current density increases (known in that art as “IQE droop”).
[0024] In an embodiment of this invention, hole current injection is inhibited in the periphery region 310 of the p-contact 140 , as illustrated in FIGS. 3A-3B , FIG. 3B being a cross section A-A′ of the device of FIG. 3A . This hole current injection inhibition region 310 may be formed by using, for example, a shallow low dose H+ implant, or other means of reducing, or blocking, current flow in this region. Such an implant may be performed after a silver deposition to form the p-contact 140 , using a photo-resist pattern to form the region 310 that is subsequently processed to create the current-inhibiting region 310 . Sufficient energy and dose for this purpose depends upon the Ag thickness but a 15 keV energy and a dose of 2e14 cm−2 are nominal values. High energy that implants deeper than 50 nm into the p-layer and high doses will create excessive damage in the p-layer and increase optical absorption.
[0025] Other means of inhibiting current flow to the p-layer 130 at the periphery may also be used, such as coating the periphery of the p-contact 140 with a resistive material 310 ′, such as a dielectric or other poorly conductive transparent material, as illustrated in FIG. 3C . The p-contact layer 140 may run up over the edge of the dielectric layer 310 ′ overlapping 310 ′ to an extent of at least 5 μm, creating in the overlapped areas a highly reflective Ag-dielectric mirror.
[0026] By inhibiting the current flow in the region 310 , the source current 300 is forced to be laterally diverted further through the n-layer 110 , as illustrated by the current flows 300 a , 300 b in FIG. 3A . Because of the lateral diversion from the periphery of the p-contact 140 , the current 300 a flows farther through the n-layer 110 before reaching the p-contact 140 than the current 200 a in FIG. 2 , and will correspondingly be reduced in magnitude. This reduction in current magnitude at the periphery will reduce the ‘hot-spot’ associated with the high current 200 a, and will reduce the likelihood of premature failure caused by the high current 200 a.
[0027] The reduction in current at the periphery of the p-contact 140 will correspondingly provide an increase in the current 300 b that flows to the center of the light emitting layer 120 , compared to the current 200 b in FIG. 2 . The overall effect, for the same amount of total current in FIGS. 2 and 3 , is a more uniform excitation of the light emitting layer 120 of FIG. 3 , which provides for a more uniform light output from the device of FIG. 3 .
[0028] Additionally, by laterally shifting the current away from the periphery of the p-contact 140 , the edge of the light emission region is relocated away from the absorbing guard region 150 , thereby reducing the amount of light that is lost to this region 150 .
[0029] It is desirable to maintain as small a radius of curvature as possible at the outer corners 320 of the p-contact layer, so as to provide a maximal reflective area below the light emitting layer 120 , thereby minimizing losses for any backscattered light. However, in a conventional device, a small radius of curvature maximizes the current crowding in the corners 320 of the device, causing even greater local hotspots at the corners. A reduction in the likelihood of local hot-spots may also be achieved by rounding the inner corners 330 of the inhibition region 310 . By creating a current inhibiting region of larger radius of curvature at the corner 330 upon a p-contact layer with a small radius of curvature at the corners 320 , the optical efficiency is maintained, and hot spots are mitigated.
[0030] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.
[0031] For example, it is possible to operate the invention by situating a contact enhancing layer, such as NiO, beneath the regions of the Ag contact where an enhanced contact is desired and eliminating this layer in the regions where the enhancement is not desired. This embodiment may be combined with a reduction in Mg doping or other impairment in the typical p-contact to reduce the effectiveness of the Ag—GaN contact.
[0032] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
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The current distribution across the p-layer ( 130 ) of a semiconductor device is modified by purposely inhibiting current flow through the p-layer ( 130 ) in regions ( 310 ) adjacent to the guardsheet ( 150 ), without reducing the optical reflectivity of any part of the device. This current flow may be inhibited by increasing the resistance of the p-layer that is coupled to the p-contact ( 140 ) along the edges and in the corners of contact area. In an example embodiment, the high-resistance region ( 130 ) is produced by a shallow dose of hydrogen-ion (H+) implant after the p-contact ( 140 ) is created. Similarly, a resistive coating may be applied in select regions between the p-contact and the p-layer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. patent application Ser. No. 11/145,303 filed Jun. 3, 2005, which claims priority of Korean Patent Application No. 10-2004-0040383 filed Jun. 3, 2004, the contents of which are herein incorporated by reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a liquid crystal display, and more particularly to an LCD having a wide viewing angle.
[0004] 2. Description of the Related Art
[0005] A liquid crystal display (LCD), which is one of the most widely used flat panel displays, typically includes two substrates having field-generating electrodes thereon and a liquid crystal (LC) layer interposed between the two substrates. To produce an image on the LCD, voltage signals are applied to the field-generating electrodes of the substrates to generate an electric field across the LC layer and thus control the orientation of LC molecules of the LC layer. The controlled orientation of the LC molecules creates an image by adjusting the polarization of incident light.
[0006] In comparison with conventional cathode ray tube (CRT) displays, an LCD has a narrower viewing angle. A number of techniques have been proposed to overcome this drawback, one of the techniques being known as Vertically Aligned (VA) mode LCD. In the VA mode LCD, the liquid crystals are vertically aligned to the substrate surface plane at the off-state where no voltage or off-voltage is applied, so that the incident light leakage through the LCD is almost zero in the black state (off state with Cross-Nicole state). Due to this minimized light leakage, the Contrast Ratio (CR) of the VA mode LCD, which represents the ratio of white state luminance to black state luminance, is higher than that of any other mode LCDs, such as Twisted-Nematic (TN) mode LCD and In-Plane-Switching (IPS) mode LCD, which employs another enhanced viewing angle technique.
[0007] As described above, the VA mode LCD provides an improved viewing angle from the standpoint of Contrast Ratio. However, in the VA mode LCD, like other mode LCDs, the color patterns viewed from the vertical direction to the LCD and from the slanted direction are recognized somewhat differently. This phenomenon (“Color Shift”) comes from the fact that the light path changes depending on the viewing angle. Accordingly, the voltage-transmittance curve (the V-T curve) or the gamma curve also change relative to the viewing angle.
SUMMARY
[0008] The present invention is directed to the structure of an LCD panel that can produce an improved visual image.
[0009] In accordance with an embodiment of the present invention, an active matrix substrate of the LCD panel includes a transistor, a pixel electrode having a first sub-pixel electrode and a second sub-pixel electrode, a first electrode connected to the second sub-pixel electrode, and a second electrode connected to the source electrode of the transistor and the first sub-pixel electrode. The second electrode is coupled to the first electrode so as to form a capacitor. The active matrix substrate can include a protective insulating layer between the second electrode and the pixel electrode, and the protective insulating layer can include a color filter layer. The semiconductor layer of the transistor can extend such that a portion of the semiconductor layer has the same boundary as the second electrode.
[0010] In accordance with another embodiment of the present invention, a LCD panel includes an active matrix substrate, a patterned substrate disposed opposite to the active matrix substrate, and a liquid crystal layer interposed between the active matrix substrate and the patterned substrate. The active matrix substrate includes a transistor, a pixel electrode having a first sub-pixel electrode and a second sub-pixel electrode, a first electrode connected to the second sub-pixel electrode, and a second electrode connected to the source electrode of the transistor and the first sub-pixel electrode. The second electrode is coupled to the first electrode so as to form a capacitor. The patterned substrate has an aperture that divides the liquid crystal layer into a plurality of domains. The first and second electrodes are formed along a portion of the aperture of the patterned substrate.
[0011] In accordance with another embodiment of the present invention, a method is provided for operating a liquid crystal display comprising a first substrate, a second substrate, and a liquid crystal layer interposed between the first and second substrates. The method comprises: applying a data voltage signal via a data line to a pixel electrode, the pixel electrode comprising a first sub-pixel electrode and a second sub-pixel electrode; applying the data voltage signal to the first sub-pixel electrode; reducing the data voltage signal to a reduced data voltage signal; and applying the reduced data voltage signal to the second sub-pixel electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a layout of an active matrix TFT (Thin-Film-Transistor) substrate according to an embodiment of the invention.
[0013] FIG. 2 shows a layout of a patterned substrate matched to the active matrix TFT substrate of FIG. 1 .
[0014] FIG. 3 shows a layout of a liquid crystal display (LCD) panel, in which the active matrix TFT substrate of FIG. 1 and the patterned substrate of FIG. 2 are overlapped.
[0015] FIG. 4 is a cross-sectional view of FIG. 3 along the line IV-IV′.
[0016] FIG. 5 is a circuit diagram of the LCD panel of FIG. 3 .
[0017] FIG. 6 shows a layout of a liquid crystal panel according to another embodiment of the invention.
[0018] FIG. 7 is a cross-sectional view of FIG. 6 along the line VII-VII′.
[0019] FIG. 8 shows a layout of an LCD panel according to another embodiment of the invention.
[0020] FIG. 9 shows a layout of an active matrix TFT substrate according to another embodiment of the invention.
[0021] FIG. 10 shows a layout of a patterned substrate matched to the active matrix TFT substrate of FIG. 9 .
[0022] FIG. 11 shows a layout of an LCD panel, in which the active matrix TFT substrate of FIG. 9 and the patterned substrate of FIG. 10 are overlapped.
[0023] Use of the same reference symbols in different figures indicates similar or identical items.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] FIGS. 1 to 4 illustrate portions of an LCD panel 500 in accordance with an embodiment of the invention. FIG. 3 shows the layout of LCD panel 500 . FIG. 1 shows the layout of an active matrix TFT substrate 100 for LCD panel 500 , and FIG. 2 shows the layout of a patterned substrate 200 matched to active matrix TFT substrate 100 of FIG. 1 . FIG. 4 is the cross sectional view of FIG. 3 along the line IV-IV′.
[0025] Referring to FIG. 4 , LCD panel 500 comprises an active matrix TFT substrate 100 , a patterned substrate 200 , and liquid crystals 310 interposed between substrates 100 and 200 . Aligning layers 11 and 21 of substrates 100 and 200 , respectively, face each other such that liquid crystals 310 can be vertically aligned to substrates 100 and 200 . In addition, polarizers 12 and 22 are provided on LCD panel 500 as shown in FIG. 4 .
[0026] Referring to FIGS. 1 , 4 , and 5 , active matrix TFT substrate 100 comprises a number of pixels 191 . Each pixel 191 includes a pixel electrode 190 , which is divided into sub-pixel electrodes 190 a and 190 b . Between sub-pixel electrodes 190 a and 190 b is an aperture 193 .
[0027] In the operation of LCD panel 500 in accordance with an embodiment of the present invention, when a data voltage signal Va is applied from a data line 171 , data voltage signal Va is applied to sub-pixel electrode 190 a through a switching transistor Q, shown in FIG. 5 . On the other hand, while voltage level Va is applied to sub-pixel electrode 190 a , a voltage level Vb reduced by a coupling capacitor Cpp is applied to sub-pixel electrode 190 b that is connected to an auxiliary coupling electrode 136 through a contact hole 186 . Sub-pixel electrode 190 a is connected to a coupling electrode 176 through a contact hole 185 .
[0028] Consequently, when data voltage signal Va is applied to pixel 191 through switching transistor Q, two different voltage levels are respectively applied to sub-pixel electrodes 190 a and 190 b . Thus, pixel 191 comes to have two sub-pixel areas having different light transmittance from each other (sometimes referred to as the gamma curve mixing effect), so that the color shift in wide viewing angle dramatically reduces. In other words, the gamma curve (gray-luminance curve) formed by merging the gamma curve of a lower voltage area and the gamma curve of a higher voltage area is less distorted than the gamma curve of a single average voltage area, when viewed at an angle. The off-axis image quality can be improved by providing sub-pixels having slightly different LC molecule tilt angles produced by the sub-pixel voltage level differential.
[0029] According to an embodiment of the present invention, a coupling capacitor Cpp (shown in FIG. 5 ) is formed by auxiliary coupling electrode 136 , coupling electrode 176 , and a gate insulator 140 (shown in FIG. 4 ).
[0030] Referring to FIGS. 1 , 3 and 4 , the structure of active matrix substrate 100 is explained in detail. Active matrix TFT substrate 100 includes a number of gate lines 121 on a substrate 110 , which deliver scanning (or gate) signals. Each gate line 121 extends to a gate electrode 124 of switching transistor Q. According to this embodiment, at the end of gate lines 121 , gate pads 129 are formed to connect gate lines 121 to an external driving circuit. The external driving circuit can be formed on a separate chip or on active matrix TFT substrate 100 . When the driving circuit is integrated on active matrix TFT substrate 100 , gate pads 129 may be omitted. On the same layer as gate line 121 , a storage electrode 133 is formed so as to form a storage capacitor Cst. Storage capacitor 133 connects to an adjacent storage capacitor through a storage line 131 . Auxiliary coupling electrode 136 is also on the same layer as gate line 121 . Sputtering processes can be used to form gate lines 121 , storage lines 131 , and auxiliary coupling electrode 136 so as to have a single-layer structure or a multi-layer structure comprising Al (or Al alloy), Mo (or Mo alloy), Cr (or Cr alloy), Ti (or Ti alloy), Ta (or Ta alloy), Ag (or Ag alloy), or Cu (or Cu alloy).
[0031] For example, gate lines 121 , storage lines 131 , and auxiliary coupling electrode 136 can have the structure of two layers including a lower layer composed of Al—Nd alloy and an upper layer composed of Mo.
[0032] Gate insulator 140 comprising silicon nitride is formed over gate lines 121 , storage lines 131 , and auxiliary coupling electrode 136 by chemical vapor deposition (CVD). An exemplary thickness of gate insulator 140 is 1000-5000 Å. Gate insulator 140 is thinner than protective layer 180 , which will be discussed later.
[0033] The capacitance of coupling capacitor Cpp is inversely proportional to the thickness of gate insulator 140 , and is proportional to the overlapping area between auxiliary coupling electrode 136 and coupling electrode 176 . Accordingly, since the thickness of gate insulator 140 is relatively small, it is possible to obtain a sufficient coupling capacitance with a relatively small overlapping area between auxiliary coupling electrode 136 and coupling electrode 176 . The reduced overlapping area improves the transmittance of LCD panel 500 .
[0034] A semiconductor layer, such as an amorphous silicon (a-Si) layer is formed by CVD over gate insulator 140 . The a-Si layer, by patterning, forms a channel area 154 in switching transistor Q and a semiconductor layer 151 under data line 171 .
[0035] An a-Si layer highly doped with n-type impurity is formed by CVD and is patterned so as to form a source ohmic contact layer 163 and a drain ohmic contact layer 165 . The patterning of the a-Si layer highly doped with n-type impurity also produces a buffer layer 161 between semiconductor layer 151 and data line 171 . In general, the a-Si layer for channel area 154 and semiconductor layer 151 and the a-Si layer highly doped with n-type impurity for ohmic contact layers 163 , 165 may be sequentially formed by CVD and are simultaneously patterned.
[0036] Over gate insulator 140 , semiconductor layer 151 , channel area 154 , and ohmic contact layers 163 and 165 are formed data line 171 , a drain electrode 175 , and a source electrode 173 of switching transistor Q. Source electrode 173 extends from data line 171 so that data signals are supplied to source electrode 173 through data line 171 . At an end portion of data line 171 , data pad 179 is formed to connect data line 171 to an external data driving circuit. Alternatively, the data driving circuit can be integrated on active matrix TFT substrate 100 and directly connected to data line 171 .
[0037] Coupling electrode 176 which extends from drain electrode 175 is formed when data line 171 is formed. Data line 171 , drain electrode 175 , and coupling electrode 176 may be formed by sputtering and patterning of a metal layer comprising, e.g., Al (Al alloy), Mo (Mo alloy), Cr (Cr alloy), Ti (Ti alloy), Ta (Ta alloy), Ag (Ag alloy), or Cu (Cu alloy). Data line 171 , drain electrode 175 , and coupling electrode 176 can have a single layer structure or a multi-layer structure. An exemplary three-layer structure of data line 171 , drain electrode 175 , and coupling electrode 176 can have an Al middle layer and upper and lower layers composed of Mo nitride or Mo—Nb alloy.
[0038] A protective layer 180 comprising a first protective layer 801 and a second protective layer 802 is formed over active matrix TFT substrate 100 after the formation of the data line 171 , drain electrode 175 , and coupling electrode 176 .
[0039] First protective layer 801 is formed of silicon nitride with a thickness of 1000-5000 Å by CVD. Second protective layer 802 is formed of an organic material with thickness of 1.0-5.0 μm by a slit or spin coating method.
[0040] Second protective layer 802 has a relatively low dielectric constant, which can be 1.0-5.0, and has a large thickness, which can be above 1.0 μm (preferably 1.0-5.0 μm). Accordingly, because the capacitance between pixel electrode 190 and data line 171 is minimized, the area of pixel electrode 190 can be increased. The increase of the area of pixel electrode 190 increases the transmittance of LCD panel 500 . In other embodiments, first protective layer 801 can be omitted. In accordance with another embodiment of the present invention, second protective layer 802 can include a color filter layer. In this case, a color filter layer 230 of patterned substrate 200 is removed.
[0041] Protective layer 180 includes contact holes 182 and 185 , which expose an end of data line 171 and a portion of drain electrode 175 , respectively. Protective layer 180 also includes contact holes 181 and 186 , which expose an end of gate line 121 and a portion of auxiliary coupling electrode 136 , respectively. Contact holes 181 and 186 extend through gate insulator 140 .
[0042] Over protective layer 180 , pixel electrode 190 including a number of sub-pixels electrodes 190 a and 190 b and redundant pads 81 and 82 is formed by sputtering of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).
[0043] Pixel electrode 190 is divided into sub-pixel electrodes 190 a and 190 b by aperture 193 . Sub-pixel electrode 190 a connects through contact hole 185 to drain electrode 175 of switching transistor Q. Sub-pixel electrode 190 b connects to auxiliary coupling electrode 136 through contact hole 186 , and auxiliary coupling electrode 136 is coupled to coupling electrode 176 to form a capacitor.
[0044] In LCD panel 500 , voltage level Vb reduced by coupling capacitor Cpp is applied to the sub-pixel electrode 190 b while data voltage level Va is applied to sub-pixel electrode 190 a.
[0045] Connecting pads 81 and 82 , which are often made of ITO or IZO, are formed to connect gate pad 129 and data pad 179 , respectively, to external driving circuits. Contact holes 181 and 182 connect pads 81 and 82 to gate pad 129 and data pad 179 , respectively. In case that the external driving circuits are formed on active matrix TFT substrate 100 , the external driving circuits may directly connect to gate and data lines 121 and 171 . Pads 81 , 82 , 129 , and 179 and contact holes 181 and 182 are omitted.
[0046] Over pixel electrode 190 , aligning layer 11 for aligning liquid crystal molecules 310 in the direction perpendicular to active matrix TFT substrate 100 is formed of a polymeric material such as polyimide.
[0047] Referring to FIGS. 2 , 3 and 4 , the structure of patterned substrate 200 will be explained. A black matrix 220 is formed on a base substrate 210 so as to prevent light leakage caused by the electric field interference by date line 171 or gate line 121 .
[0048] A color filter layer 230 , which includes red, green, and blue elements, is formed on black matrix 220 and substrate 210 so as to express various combinations of colors.
[0049] An overcoat layer 250 is formed over color filter layer 230 so that the surface of overcoat layer 250 is substantially flat. Then, a common electrode 270 , which is made of a transparent conductive material such as ITO or IZO, is formed by sputtering on overcoat layer 250 . Common electrode 270 includes a number of apertures 271 .
[0050] The arrangement of apertures 193 and 271 are designed so as to control the liquid crystal domain by directing liquid crystals 310 into pre-determined orientations. The average orientation of liquid crystals is preferably at a 45° angle relative to the polarizing axes of the polarizing films of the LCD display. Generally, the polarizing axes of polarizing films are parallel or perpendicular to the data line and the average orientation of liquid crystals is perpendicular to that of the aperture. Accordingly, the apertures may be formed to be diagonally oriented. Depending on the layout of apertures 193 and 271 , the liquid crystal texture can be reduced, and light-transmittance can be improved. For example, notches 262 of aperture 271 can provide more precise control of liquid crystals 310 in a certain region.
[0051] In another embodiment according to the present invention, alternative means such as protrusions can be used for the domain control. These protrusions are generally formed on the pixel electrode and/or the common electrode and are made of an organic material. It is also possible to mix protrusions and apertures as domain controlling means. For example, the apertures are formed on the active matrix TFT substrate 100 and the protrusions are formed on patterned substrate 200 , or the protrusions are formed on active matrix TFT substrate 100 and the apertures are formed on patterned substrate 200 .
[0052] After being fabricated as described above, active matrix TFT substrate 100 and patterned substrate 200 are assembled with each other, and liquid crystals 310 are interposed between active matrix TFT substrate 100 and patterned substrate 200 .
[0053] FIGS. 6 and 7 illustrate LCD panel 500 in accordance with another embodiment of the present invention. FIG. 6 is the layout of LCD panel 500 , and FIG. 7 is the cross sectional view of LCD panel 500 along the line VII-VII′ of FIG. 6 .
[0054] LCD panel 500 of FIGS. 6 and 7 is basically the same as LCD panel 500 of FIGS. 3 and 4 , except with respect to the layout of the semiconductor channel area and ohmic contact layer of the switching transistor Q. Accordingly, detailed explanation on the common structure will be omitted.
[0055] Referring to FIG. 7 , semiconductor channel area 154 , a semiconductor layer 154 ′ extending from semiconductor channel area 154 , and semiconductor layer 151 have substantially the same boundary as data line 171 , source electrode 173 , drain electrode 175 , and coupling electrode 176 . This same boundary profile results in when the a-Si layer for semiconductor channel area 154 and semiconductor layers 151 and 154 ′ and the metal layer for data line 171 , source electrode 173 , drain electrode 175 , and coupling electrode 176 are simultaneously patterned.
[0056] The simultaneous patterning, after the deposition of an a-Si layer, an a-Si layer highly doped with n-type impurity, and a metal layer, uses a slit-mask photo resist pattern. In the slit-mask photo resist pattern, a slit with a half-tone exposure is formed at a region corresponding to channel area 154 so as to control the depth of patterning. This simultaneous patterning of FIG. 7 , in comparison to the two-step patterning of FIG. 4 , reduces fabrication cost and time.
[0057] FIG. 8 is a layout of an LCD panel 500 according to another embodiment of the invention. LCD panel 500 of FIG. 8 is basically the same as LCD panel 500 of FIGS. 3 and 4 , except with respect to the layout of coupling electrode 176 and auxiliary coupling electrode 136 . Therefore, detailed explanation on the common structure will be omitted.
[0058] Referring to FIG. 8 , coupling electrode 176 and auxiliary coupling electrode 136 are formed along a portion of apertures 271 of common electrode 270 of FIG. 2 , so that light leakage through aperture 271 is reduced. Accordingly, light transmittance of LCD panel 500 can be increased.
[0059] FIGS. 9 , 10 , and 11 illustrate an LCD panel 500 in accordance with another embodiment of the invention. FIG. 9 is the layout of active matrix TFT substrate 100 , FIG. 10 is the layout of patterned substrate 200 , and FIG. 11 is the layout of LCD panel 500 . LCD panel 500 of FIG. 11 is basically the same as LCD panel 500 of FIGS. 3 and 4 , except with respect to the layout of domains and apertures 196 of pixel electrode 190 and common electrode 270 . Therefore, detailed explanation on the common structure will be omitted. LCD panel 500 of FIG. 11 has more apertures 196 and domains than LCD panel 500 of FIGS. 3 and 4 . The increased number of apertures 196 and domains can prevent color shifts in viewing angle while effectively controlling liquid crystals in a relatively large size pixel area.
[0060] As described above, according to the present invention, in case of using gate insulator 140 as an interposing dielectric layer of a coupling capacitor, it can be possible to obtain sufficient coupling capacitance with a relatively small overlapping area of opposing electrodes, so as to minimize the reduction of transmittance due to overlapping area of opposed electrodes and simultaneously to prevent color shifts in viewing angle.
[0061] Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those specific embodiments, and that various changes and modifications may be affected therein by one of ordinary skill in the related art without departing from the spirit and scope of the present invention. All such changes and modifications are intended to be included within the scope of the invention as defined in the appended claims.
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A method of manufacturing an active matrix substrate is presented. The method includes forming a transistor having a gate line, a semiconductor layer, an insulating layer between the gate line and the semiconductor layer, a source electrode, and a drain electrode; forming a pixel electrode comprising a first sub-pixel electrode and a second sub-pixel electrode; forming an auxiliary coupling electrode connected to the second sub-pixel electrode through a first contact hole; and forming the first sub-pixel electrode through a second contact hole connected to the drain electrode of the transistor. The auxiliary coupling electrode and the first sub-pixel electrode overlap each other such that the second sub-pixel electrode is capacitively coupled to the first sub-pixel electrode and the auxiliary coupling electrode and the electrode part form a capacitor.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of my application Ser. No. 08/777,407, filed Dec. 30, 1996, now U.S. Pat. No. 5,740,830.
FIELD OF THE INVENTION
The present invention pertains to a plumbing tool and more particularly to a plumbing tool for providing a passageway through a blockage in a fluid-carrying line.
BACKGROUND
In residential house construction and as is well known, the plumbing is basically installed in three stages, namely, the rough-in plumbing, top-out plumbing and finish plumbing. The rough-in plumbing occurs prior to pouring of concrete. Top-out plumbing follows framing the building and involves installing the pipes in the walls and vent pipes that extend up through the roof of the structure. Finish plumbing relates to setting toilets, sinks, and the like.
The rough plumbing includes laying a drain or waste pipe which leads from building to the city sewer main normally in the access street or road adjacent to the building. It is common practice to insert a clean-out in the drain pipe between the pipes in the building and the section of the drain pipe that leads to the sewer line. This clean-out may be located in a basement or, in a building without a basement, outside the building and underground. If underground, the clean-out has a branch extending to the surface of the ground for providing access to the drain pipe both during construction and during use of the building.
As is well known, in order to pass the rigid inspection normally imposed by building codes, it is necessary to test the drainage part of the plumbing system after the rough-in and top-out stages are finished. For this purpose, common procedures and devices are in use. The devices include test caps and inflatable test plugs, so-called water-weenies. In use, the test caps are sealed at the ends of all open and exposed branch pipes, and the inflatable test plugs are used in the clean-out where the passageway plugged is not as accessible. After the tests, the exposed test caps are punched out with a hammer, and the inflatable plugs are deflated and pulled out of the clean-out. Thus, the test plugs and the inflatable plugs can be removed without disassembling and disturbing the tested system.
As indicated, the test caps in above-ground, accessible locations are usually knocked out with a hammer, whereupon the fragments are pried out with a screwdriver or pliers. If a test cap were sealed in a clean-out, however, whether the clean-out is relatively accessible in a basement or whether it is underground, it cannot be punched out with a hammer and screwdriver without disassembling part of the system and thereby disturbing the tested system. Thus test caps have not been used to block the test pressure in the drain pipe.
Instead, during the rough-in plumbing stage the inflatable weenie-shaped, test plugs have been inserted in the clean-out, used for the tests and subsequently removed with a pull chain attached to the plug and extending out of the clean-out. More specifically to test the rough-in plumbing the plug is inserted and inflated thereby sealing the drain pipe. The plumbing on the building side of the plug is then pressurized to check for leaks. After the top-out phase is completed the plumbing is again tested by again inflating the plug, and pressurizing the system, usually by feeding water into the system through the vent pipes in the roof.
Use of such inflatable weenie plugs for the described testing has proved unsatisfactory for several reasons. The essential problem is that the plugs often leak although the plumbing may be entirely sound. Either the plug does not seal perfectly circumferentially within the pipe or the plug is punctured as it is being slid in or out of the clean-out and against the rough surfaces thereof. As a result, the test fails, not because of faulty plumbing, but because of a faulty plug, the plumbing crew will then need to be called back to the job to attend to the problem, causing aggravation and extra expense to the contractors and owners involved. Not only is there extra labor cost involved, hut the failed inflatable test plugs must be replaced at considerable expense.
SUMMARY
A plumbing tool for providing a passageway through a blockage, such as a test cap or other blockage, in a fluid-carrying line is provided. During the rough-in plumbing phase of construction, the drain pipe leading from the plumbing, system in a building to the city sewer main in the street is positively sealed off by a test cap welded in the pipe at the location of the clean-out. Pressurizing the rough-in plumbing to test the same can then proceed knowing that if any leaks occur, they are in the branch plumbing on the building side of the test cap and not at or in the test cap. Following successful completion of the initial test the top-out plumbing is completed, leaving the test cap welded in the clean-out or drain pipe. After the roof vents are in, the top-out test of the plumbing system is made, again knowing that if the system shows any leaks, they are the result of a failure in the plumbing work and not a failure of the test cap. After the plumbing system has passed final test and inspection, a special tool constructed in accordance with the present invention is inserted down the clean-out to penetrate and ream-out the test cap, so that the drain pipe is at substantially its normal inside diameter and provides a relatively full opening through which the waste can flow to the city sewer main in the street. The tool is also useful for cutting through other blockages in the line.
An object of this invention is to be able to provide a passageway through a test plug or other blockage in a fluid-carrying line.
Another object is to provide a tool that can be extended into a clean-out and can cut out a plug or other blockage that is secured in a fluid-tight manner in a drain pipe to which the clean-out is connected.
Still another object is to be able from a remote position to maneuver and guide a cutting head of a tool inside a clean-out and into a position therein to ream out a test cap welded in the clean-out or other blockage in the line.
A further object is to provide a tool that can flex around a transition such as a corner from a branch line to a main line and thereby cut-out a blockage in the main line.
An additional object is to provide a tool for cutting a test cap out of a clean-out and that is adapted to attach cutting heads of different sizes for different diameter pipes.
Yet another object is to provide a test cap- or other blockage-removing tool that is adapted to change its length depending on the distance between the test cap-to-be-removed and the location of the operation of the tool.
A further object to provide a test cap-removing tool that cooperates with a clean-out to leverage the cutting head into a cutting position and then allows the cutting head to ream out the test cap or other blockage.
A still further object is to enable a test plug or other blockage that has been welded or otherwise fixed in fluid-tight relation in a drain pipe to be removed so that nearly the full diameter of the drain pipe is available for conducting material therethrough after the plug or other blockage has been removed.
These and other objects and advantages of the invention will become apparent upon reference to the accompanying drawings and the following detailed description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view slowing a schematic representation of a plumbing installation in a residential building construction that is intended to represent the plumbing installation after the rough-in plumbing or first stage of the plumbing installation has been completed and during which a clean-out is installed in a drain pipe leading from the building to a public sewer line.
FIG. 2 is an enlarged exploded isometric view of a part of FIG. 1, showing fragments of upper and lower sections of the drain pipe, showing the clean-out with a branch thereof (partially broken away) to be connected to the lower section of the drain pipe and showing a test cap to be connected to the lower section between the section and the branch of the clean-out.
FIG. 3 is a still further enlarged view similar to FIG. 2 but with the parts assembled, thereby showing the clean-out connected between the upper and lower sections of the drain pipe and showing the test cap connected to the lower section between that section and the clean-out so as to block flow through the clean-out from the upper section of the drain pipe to the lower section thereof.
FIG. 4 is a still further enlarged end view of the test cap shown in FIGS. 2 and 3 as seen from the upstream end of the cap.
FIG. 5 an exploded longitudinal diametrical section of the test cap taken on a plane indicated by line 5--5 of FIG. 4 but showing the test cap between the drain pipe and the clean-out and illustrating how these three parts will interfit when assembled.
FIG. 6 is a view similar to FIG. 1 but on a reduced scale and intended to represent the plumbing system after the second or top-out stage thereof has been completed.
FIG. 7 is an isometric view of a tool used in carrying out the method of the present invention and including a cutting head, a flexible shaft, and handles.
FIG. 8 is an enlarged end view of the cutting head of the tool shown in FIG. 7.
FIG. 9 is an enlarged, exploded, isometric view of the tool of FIG. 7 with the head and shaft being fragmentary and showing how the cutting head is releasably connected to the shaft.
FIG. 10 is an enlarged isometric view of the shaft showing the turns of the coil spring construction of the shaft.
FIG. 11 is a reduced exploded isometric view of the tool of FIG. 7 and showing how the handles are connected to the shaft.
FIG. 12 is an isometric view similar to and on the same scale as FIG. 3 with an extension pipe connected to the clean-out, with the tool of FIG. 7 extended into the clean-out, and with part of the clean-out broken away to show the cutting head of the tool in cutting engagement with the center plate of the test cap.
FIG. 13 is an enlarged fragmentary, vertical longitudinal section of the clean-out and part of the lower section of the drain pipe and showing the tool with its cutting head in cutting engagement faith the center plate of the cap.
FIG. 14 is a view similar to FIG. 12 but with the tool removed and with the clean-out broken away to show how the cutting head has completely removed the center plate of the test cap thereby to open the drain pipe for movement of drain materials therethrough.
DETAILED DESCRIPTION
Prior to describing the method and apparatus of the present invention, reference will be briefly made to the environment in which the invention is used. Thus in FIG. 1, a plumbing system is schematically shown and generally indicated by the numeral 20 in a residential building construction 22, with the plumbing system being represented at the rough plumbing stage. Only the foundation area 24 and a few of the interior pipes 26 of the plumbing system are shown thereby indicating that only the basic pipes have been installed and that none of the finish plumbing is in nor are the appliances installed.
During the rough-in plumbing stage (FIG. 1), a drain pipe 36 is connected between the interior plumbing 26 and a city sewer main or public sewer line 38 which usually runs underneath the street or road in front of the construction 22. The drain pipe is typically made of a plastic such as ABS or PVC, but it may be cast iron or copper or other suitable material. For drainage purposes, the pipe usually has a three- or four-inch diameter and is laid with enough slope to enable drainage. As is well known, the ground 42 around the construction is excavated to provide a large trench or open area 44 below normal ground level so the drain pipe can be connected to the sewer line. The drain pipe has an upper section 46 connected to the interior plumbing and a lower section 48 connected to the sewer line.
A three-way clean-out 56 (FIGS. 1, 2 and 3), usually of the same material as the drain pipe 36, has inlet, outlet and clean-out branches 58, 60 and 62, each having a collar 64 and an annular shoulder 66. The collars of the inlet and outlet branches are respectively slid over and cemented to the upper and lower sections 46 and 48 of the drain pipe with the shoulders of the clean-out normally abutting the ends of the pipe sections. A riser 68 is connected to the clean-out branch and extends above the surface of the ground 42, and a clean-out cover 69 is releasably connected to the riser for sealing and closing this branch when necessary.
As is well-known, building codes typically require plumbing installations for new construction to be tested for leaks twice: after the rough-in plumbing is in and after the top-out plumbing is completed. It is currently standard practice to insert an inflatable plug, not shown, down the clean-out branch 62 and into the outlet branch 60, to inflate the plug, and thus to block the drain pipe 36 so the plumbing system can be pressurized for leaks. Since such plugs have not been satisfactory as discussed above, the principles of the present invention involve conducting the tests differently.
In accordance with the method of the present invention and as part of the rough-in plumbing phase (FIGS. 1-5), a test cap or plug 70 of well-known construction is fitted in and connected to the lower section 48 of the drain pipe 36, and then the clean-out 56 is connected between and joins the upper and lower sections 46 and 48 of the drain pipe. The test cap has an annular body 72, an annular flange 74 extending radially outwardly from the body, and a circular center plate 76 filling the body.
Test caps, as 70 (FIGS. 2 through 5). suitable for the purposes of the present invention are sold by the PASCO Company of 11156 Wright Road, Lynwood, Calif. 90262, as part Nos. 4844 and 4845. These caps are of plastic material capable of being solvent-welded to ABS or PVC pipe, and are also commonly referred to as knock-out plugs. They are available in various sizes so that their annular bodies 72 can be fitted in three- or four-inch diameter drain pipes 36.
As above stated and during the rough-in plumbing stage, the test cap (FIGS. 2 and 5) is fitted in the lower section 48 of the drain pipe with the body 72 received within the pipe, the flange 74 engaging the end of the pipe, and the center plate 76 disposed transversely of and within the pipe. Prior to making this assembly, layers of a suitable bonding cement are applied as at 78 to the mating surfaces so as to solvent-weld the parts together in the described assembly. After the test cap is welded in place (FIG. 13), the collar 64 of the outlet branch 60 of the clean-out is slipped over and solvent-welded to the lower section of the drain pipe with the shoulder 66 of the outlet branch abutting the radial flange 74 of the test cap. The resulting connection (FIG. 3) of the test cap in the drain pipe effects a fluid-tight seal that will block flow through the pipe. Either before or after this connection, the inlet branch 58 of the clean-out is connected to the upper section 46 of the drain pipe.
Following the described assembly (FIGS. 1 and 3) of the test cap 70, the clean-out 56, and the upper and lower sections 46 and 48 of the drain pipe 36, the rough-in plumbing is subjected to a first pressure test. Such pressurization is accomplished in a well-known manner that includes introducing water into the system through an open end of a pipe in the interior plumbing 26. It is of course understood and well known that all open ends of the pipes in the system 20 are plugged including attaching the clean-out fitting 69 to the riser 68 of the clean-out branch 62. Such pressurization imposes fluid pressure on the upstream side of the test cap on the side thereof opposite from the sewer line 38. Since the test cap is bonded in fluid-tight relation within the drain pipe, no leaks will occur through or around the test cap. As a result, if there is any loss of pressure in the plumbing system, it will clearly be in the plumbing system itself and not in the plugging of the drain pipe by the test cap, as contrasted with the frequent leaks of the inflatable test plugs, as described above.
After the plumbing system 20 has passed the initial test at the rough-in plumbing stage, construction of the building continues (FIG. 6) including completion of the top-out plumbing job. This involves installation of one or more roof vents, as 86, extending up through the roof of the building, represented at 88. As part of finishing the construction, the ground 42 around the building is filled and graded, leaving the riser 68 exposed above ground level to allow access to the clean-out 56.
During the completion of the building 88 (FIG. 6), the test cap 70, the clean-out 56 and the drain pipe 36 are not disturbed and thus remain connected in the described relationship (FIG. 3). After the top-out stage is completed, a second test of the plumbing system 20 is conducted by again pressurizing the system 20 but this time typically by feeding water with a hose through an open roof vent, as 86. Once more, the test cap absolutely blocks flow through the drain pipe so that if there are any leaks in the system, they will be in the system and not in the plug in the drain pipe. If the system is sound, only one additional test is needed, but of course if there are leaks, they must be repaired and the test repeated until all problems are corrected.
Following successful passage of the second or final test or tests. however, it is of course necessary to remove the blockage caused by the test cap 70. In accordance with the principles of the present invention, the blockage is removed by a special plumbing tool 100 (FIGS. 7-11). This tool includes an elongated flexible shaft 102. preferably about four feet long and preferably about 3/4" in diameter, and having upper and lower ends 104 and 106. In the disclosed embodiment, the shaft is a tightly wound coil spring 108 (FIG. 10) made of wire, the adjacent turns 110 of which are in close engagement when the shaft is unflexed, thereby imparting a measure of rigidity to the shaft notwithstanding its flexibility. Coil springs, as 108, suitable for the shaft of the present invention are sold as part No. 9504 by the Marco Products Company of Sylmar, Calif. Alternatively, other types of flexible shafts or cables with a measure of rigidity can be employed.
The plumbing tool 100 (FIGS. 7-11) also includes a cutting head 120 with a conical configuration releasably attached to the lower end 106 of the tool shaft 102. The cutting head has a mounting ring 122 disposed perpendicularly of the axis of the shaft when the shaft is straight and unflexed as in FIG. 7, a cruciform mounting bracket 124 secured within the ring, and a hub 126 extending from the bracket axially of the ring. The outside diameter of the mounting ring is of a dimension suitable for the size of clean-out 56 being used so that the ring will slidably and rotatably fit within the clean-out (FIG. 13). A lower coupling 130 (FIG. 9) is connected to the lower end 106 of the spring shaft, is fitted over the hub, and is fastened thereto by a set screw 132 on the coupling.
More specifically the lower coupling 130 (FIG. 9) has a female sleeve 134 that slips over the hub 126. The hub has a hole 128 that is aligned with and receives the set screw 132 to secure the coupling to the mounting ring 122. The lower coupling also has a threaded male stub 135 that threads into the lower end 106 of the spring shaft 102 thereby to secure the coupling to the shaft. It will be understood that the coupling 130 allows different sizes of cutting heads 120 to be connected to the tool shaft depending on the diameter of the drain pipe involved.
The cutting head 120 (FIGS. 7, 8, and 13) also has a plurality of triangular cutting blades 136 rigidly secured to and projecting endwardly from the mounting ring 122 and bracket 124. Four blades are used in the disclosed embodiment and are positioned in the four quadrants of the mounting ring and bracket with the base edges of blades welded to the mounting ring and bracket and the altitude edges of the tour blades welded together along the axis of the ring. The blades have axial guiding edges 137 and cutting edges 138 converging to a sharp point or tip 140 of the cutting head. The base edges are set radially inwardly (FIGS. 8 and 13) of the outside diameter of the mounting ring to leave an annular stop rim 142 circumscribing the blades adjacent to the mounting ring for a purpose to be described. When the tool shaft 102 is straight and unflexed (FIG. 7), the tip of the cutting head projects endwardly from and in coaxial alignment with the shaft.
In addition, the plumbing tool 100 (FIGS. 7 and 11) has a handle 150 that includes a crankshaft 152 connected to the upper end 104 of the tool shaft 102 and a crankhandle 154 projecting from the crankshaft. The crankshaft is connected to the tool shaft by an upper coupling 130 and set screw 132 in the same manner as the cutting head 120 is connected to the tool shaft, as described above. The handle also includes a holding sleeve 156 rotatably received on the crankshaft between the upper end of the upper coupling and the crankhandle.
It is to be noted that the length of the tool shaft 102 can be changed by connecting sections of springs as 108, for example each about two feet in length, together by intermediate couplings, not shown, but similar to the upper and lower couplings 130. As contrasted with the upper and lower couplings, however, the intermediate couplings have threaded male stubs at both ends for threading into adjacent open ends of adjacent springs. Thus, by having a supply of the spring sections and the intermediate couplings, the shaft can be made longer or shorter to suit particular jobs. Also, although the shaft in disclosed embodiment is a single length of spring preferably about four feet long, it may be made up of shorter lengths of springs (for example, and as above noted, each about two feet long) equaling four feet or any other desired length.
The plumbing tool 100 (FIG. 7) is held by grasping the sleeve 156 in one hand and the crankhandle 154 in the other hand. The tool shaft 102 and thus the cutting head 120 are rotated by turning the crankhandle while holding the sleeve. Also the tool shaft has sufficient rigidity to allow force to be transmitted through, and axially of the shaft to the tip 140 by grasping the sleeve in one hand and the crankhandle in the other and thrusting the tool axially of the tool shaft. Such rotation and axial thrusting can be accomplished at the same time whether the tool shaft is straight or flexed.
The plumbing tool 100 is used to carry out the method of the present invention after all necessary pressure tests have been successfully completed. To this end, the cover 69 (FIG. 6) is removed and the cutting head 120 of the tool is inserted in the riser 68 (FIG. 12) and lowered down into the clean-out 56. The mounting ring 122 slidably engages the interior of the riser and the clean-out branch 62 and guides the cutting head down the clean-out until it exits the clean-out branch and strikes the base 59 of the clean-out (FIG. 12). Axial thrust is then imparted to the tool shaft 102 to cause the cutting head to tip over from a generally vertical attitude, not shown, into the generally horizontal attitude shown in FIG. 12, with the mounting ring engaging the base of the clean-out and the tip 140 pointing toward the test cap 70. Such tipping is facilitated by the flexibility of the shaft and the engagement of the shaft with the clean-out branch along area 170, but also by the downward slope of the drain pipe 36.
When in this generally horizontal position (FIGS. 12 and 13), further axial pressure on the tool shaft 102 causes the cutting head 120 to move axially downwardly of the drain pipe 36 toward the outlet branch 60. Because of the combined flexibility and rigidity of the tool shaft and the leveraging effect of the shaft bearing against the clean-out branch 62 and/or the riser 68 at region 170, this axial pressure on the tool shaft causes the tip 140 of the cutting head to move into engagement with the center plate 76 of the test cap 70. Then, the shaft is thrust sharply downwardly to force the tip of the cutting head to penetrate the plate creating an initial hole 174 (FIG. 12) in the plate.
Thereafter, while continuing to apply axial downward pressure on the tool shaft 102 (FIG. 13), the tool shaft and the cutting head 120 are rotated with the crankhandle 154 to begin cutting away the center plate. The mounting ring 122 is soon rotatably slidably received in the outlet branch 60 and thereafter guides movement of the cutting head axially along the outlet branch. As the cutting action continues, the guiding edges 137 move within the annular body 72 of the test cap 70 to guide and center the cutting head. When the stop rim 142 strikes the radial flange 74, the cutting blades will have substantially completely cut or reamed out the center plate 76 from within the annular body 72 of the test cap to provide a large opening 180 (FIG. 14) in the test cap. This opening 180 is the about the same diameter as the inside diameter of the body since the diameter of the cutting head at the guiding edges 137 is the about the same diameter as the inside diameter of the body. In turn, the inside diameter of the body is just slightly less than the inside diameter of the drain pipe, so that creating the opening 180 will allow waste material to move essentially unimpeded through the pipe.
After the opening 180 has been created, the tool 100 is pulled back out of the outlet branch 60 and thence out of the clean-out branch 62 and riser 68. Because the stop rim 142 contacts the radial flange 74 of the test cap 70, the cutting head 120 does not hang-up or become locked in the clean-out. It is also to be noted that the cut fragments, not shown, of the center plate are subsequently flushed down the lower section 48 of the drain pipe to the sewer line 38.
From the foregoing it will be understood that an improved method for testing a newly installed plumbing system has been provided including a tool 100 used in carrying out the method. The method is more cost-effective because it avoids having to re-test a plumbing system 20 that would have passed the test but did not only because the test plug failed. Since the method does not use inflatable test plugs to seal of the drain pipe 36 while doing the testing, the common failure of the inflatable plug does not cause a failed test. Instead the method involves use of a test cap which positively seals the drain pipe and allows an accurate test of the plumbing system. The test cap and its positive seal can be employed because the method also uses the tool 100 that can be extended into the clean-out and operated from a remote position to cut an opening 180 in the cap and remove the blockage from the pipe. It will be recognized that although the method and tool have been described and shown with an underground clean-out they can be used equally as well when the clean-out is in a basement or otherwise above ground.
It will also be more generally recognized that since, as stated above, the test cap 70 is a blockage in the line, the tool is useful not only for removing test caps but also any such blockage that is so fixed or secured in the line that it prevents, either partially or completely, fluid flow therethrough.
Although a preferred embodiment of the present invention has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly it is to be understood that the present invention has been described by way of illustration and not limitation.
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A plumbing tool for providing a passageway through a blockage, such as a test cap or other blockage, in a fluid-carrying line. During the rough-in plumbing phase of construction, the drain pipe leading from the plumbing system in a building to the city sewer main in the street is positively sealed off by a test cap welded in the pipe at the location of the clean-out. Pressurizing the rough-in plumbing to test the same can then proceed knowing that if any leaks occur, they are in the branch plumbing on the building side of the test cap and not at or in the test cap. Following successful completion of the initial test, the top-out plumbing is completed, leaving the test cap welded in the clean-out or drain pipe. After the roof vents are in, the top-out test of the plumbing system is made, again knowing that if the system shows any leaks, they are the result of a failure in the plumbing work and not a failure of the test cap. After the plumbing system has passed final test and inspection, a special tool constructed in accordance with the present invention is inserted down the clean-out to penetrate and ream-out the test cap, so that the drain pipe is at substantially its normal inside diameter and provides a relatively full opening through which the waste can flow to the city sewer main in the street. The tool is also useful for cutting through other blockages in the line.
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FIELD OF THE INVENTION
This invention relates to a method of removing zinc from galvanized steel.
BACKGROUND OF THE INVENTION
Over half of North American zinc shipments are used for the production of galvanized steel. There is a significant scrap rate in mills producing galvanized sheet (this can be on the order of 15 to 20%), and the scrap rate in the plants of primary fabricators of galvanized sheet can be as high as 25% or more. Thus, over one million tons of fresh galvanized scrap are produced each year.
Galvanized scrap is normally purchased by steel mills at a substantial discount to non-galvanized material. This discount is necessary because the galvanized scrap must be fed to melting furnaces where the zinc vaporizes and is trapped in the flue dust, with the result that this flue dust cannot be easily sold or recirculated to the furnace. Further, there are now environmental constraints on disposal of zinc containing dusts as land-fill. Also, feeding excessive amounts of galvanized scrap to basic oxygen steel-making furnaces (BOF) can result in costly shut-downs for cleaning and refractory repair. Thus, there is great interest in development of an economical method of removing zinc from galvanized scrap. Although no process has been transferred as of now to successful commercial practice, at least six approaches have been described:
a) Dissolution of Zinc with Pickle Liquor
Pickle liquor discharged from de-scaling steel products can be contacted with scrap galvanized steel to remove zinc in 5 to 10 minutes. Both sulfuric acid and hydrochloric acid have been used in this process. However, the major problem lies in the separation of iron which is co-dissolved with zinc in the acid solution An economically feasible method for this step has not yet been found.
b) Dissolution with Ammonium Carbonate Solution
In this process galvanized steel scrap is contacted with ammonium carbonate solution containing an excess of ammonia at about 170° C. Zinc dissolution is achieved in approximately 6 hours, compared with about 15 hours at room temperature. The resulting zinc ammonium carbonate complex solution is stripped of ammonia and carbon dioxide by steam injection, and zinc carbonate is precipitated. Heating of the zinc carbonate produces zinc oxide. The ammonia and carbon dioxide evolved are utilized to regenerate the original leaching solution. The major drawback to this procedure is the process time required This implies high capital and processing costs, and thus makes this procedure unattractive economically.
c) Dissolution of Zinc with Caustic Soda
Dissolution of zinc from galvanized scrap in a caustic soda solution is considered to be more economical than either of the two preceding alternatives An inherent advantage of this method is that the underlying iron layer is stable in caustic, and as a result zinc/iron separation after treatment is not a major problem. However, in this method the zinc/iron alloy layer is not readily dissolved and, as this layer is of variable thickness depending on the method of galvanizing, both zinc recovery and the zinc removal rate are variable. Insufficient zinc removal in some cases results in a product which is not much better than the starting material. Further, the process can be exceedingly slow, making it uneconomic in industrial practice.
d) Recovery as Zinc Chloride
In a process developed by Dupont (Gregory, J.E., "Chemical Processes for Dezincing Galvanized Scrap", U.S. Pat. No. 2,307,625, Jan. 5, 1943), zinc is dissolved from galvanized scrap in a zinc chloride solution containing a small amount of hydrochloric acid. In this method, iron dissolution is kept to a minimum by the use of suitable organic inhibitors, and the zinc is later recovered by boiling to precipitate zinc oxide. This and related processes have proved to be uneconomical, because of their complexity and the resulting large amount of handling which is required. A further problem is the incompatibility of chloride-containing secondaries with conventional zinc electrorefineries.
e) Acceleration of Zinc Removal with Oxidizing Agents
Dissolution of zinc from galvanized steel in caustic electrolyte, as described above, can be accelerated by addition to the electrolyte of oxidizing agents such as hydrogen peroxide, oxygen, or nitrate compounds such as sodium nitrate. All of these additives, however, have drawbacks which impede their being used in practice Hydrogen peroxide is costly, making the process uneconomic. Oxygen accelerates the rate of zinc dissolution somewhat, but not enough to make the process economic. Use of nitrates entails costly provisions for maintaining constant chemistry in the treatment electrolyte; further, formation of cyanides has been reported from reaction with oils which can be present on galvanized scrap.
f) Power-Assisted Removal in Caustic Electrolyte
Numerous patents have described methods for dissolution of a coating layer of metal from an underlying base metal, based on use of an external source of voltage to pass current through the treatment bath (Canadian patent 870,178; U.S. Pat. Nos. 2,578,898, 2,596,307, 3,394,063, 3,492,210, 3,619,390, 3,634,217, and 3,649,491). A recent announcement in American Metal Markets (Apr. 18, 1990, page 3) describes piloting of a process of this type in which zinc has been removed from bundles of galvanized steel of four types: hot-dipped; electrolytic; galvalume; and galvannealed. While this appears to be the most practical of the procedures described above, it suffers from three fundamental problems. First, costly electric power must be used to strip the zinc from the galvanized steel; at typical power rates this cost can be on the order of $10 to $15 per ton of scrap. Also, rectifiers, conductors, breakers and related equipment add significantly to the installed cost of a dezincing facility. Secondly, substrate iron dissolves as zinc dissolution nears completion; it is very difficult in practice to avoid significant co-dissolution. Thirdly, the dissolved zinc, iron and other impurities deposit directly on the cathodes which are used to promote electrolytic dissolution. The resulting deposits are impure, reducing their economic value and limiting options for further purification and recycling of the zinc.
SUMMARY OF THE INVENTION
The present invention is based on galvanic dissolution of zinc from galvanized steel in caustic electrolytes, but it avoids all three of the limitations described above in connection with zinc dissolution using imposed current.
Being a very electronegative metal, zinc is thermodynamically unstable in the presence of water and aqueous solutions, tending to dissolve with the evolution of hydrogen in acid or alkaline solutions. Iron is unstable in aqueous solutions below a pH of 7 to 9, dissolving readily as ferrous ions. At higher pH's, however, iron is almost immune to corrosion, with dissolution to dihypoferrite ion (HFeO 2 -) or oxidation to magnetite (Fe 3 O 4 ) or ferrous hydroxide (Fe(OH) 2 ) occurring only very slowly. Thus, in accordance with the present invention zinc is removed from galvanized steel without significant co-dissolution of the underlying iron by immersing the galvanized steel in a caustic solution. In fact, the practice of this invention is preferably limited to solutions of pH greater than 11, in order to avoid limitations on the reaction rate which would result due to formation of zinc oxide or zinc hydroxide on the zinc metal. Also, pH values less than 15.5 are preferred, in order to minimize dissolution of iron from the galvanized steel substrate.
When a piece of galvanized steel is immersed as has been described above in an aqueous solution having a pH between 11 and 15.5, local electrochemical cells are established with zinc dissolving anodically as bizincate ion (HZnO 2 -) or zincate ion (ZnO 2 -), and hydrogen evolving on cathodic sites. The potential difference is between 450 and 600 mV, with the exact value depending upon the concentration of bizincate or zincate ion in solution. However, this reaction often takes place extremely slowly when the zinc is pure, because of the large overpotential for the evolution of hydrogen on zinc. For example, in an experiment it was found that a sample of galvanized steel sheet having a zinc coating of 1.25 ounces per square foot did not significantly change in appearance after being immersed in a 20% sodium hydroxide solution at 60° C. for 16 hours. A regular, but very slow rate of evolution of hydrogen was observed on the galvanized surface in this experiment. This process results in some consumption of caustic, according to the following equations:
______________________________________Anodic - Zn + 4OH.sup.- → ZnO.sub.2.sup.-- + 2H.sub.2 O + 2e.sup.- (1)Cathodic - 2e.sup.- + 2H.sub.2 O → H.sub.2 + 2OH.sup.- (2)Overall - Zn + 2OH.sup.- → ZnO.sub.2.sup.-- + H.sub.2 (3)______________________________________
The caustic consumption is 1.2 kg of caustic soda (NaOH), or 1.7 kg of caustic potash (KOH), for each kilogram of zinc which is dissolved.
It is known that the corrosion of pure zinc in aqueous solutions can be greatly accelerated if the zinc is put in contact with a metal of low hydrogen overvoltage such as platinum (M. Pourbaix, "Atlas of Electrochemical Equilibria", National Association of Corrosion Engineers, Houston, 1974, p. 409). The applicant has discovered that this phenomenon can be the basis of a practical and economic method for removing zinc from galvanized steel scrap.
In essence, the method in accordance with the present invention advantageously further comprises the step of contacting the steel from which zinc is to be removed in caustic electrolyte with a cathode material which is stable in caustic electrolyte and is characterized by a low overvoltage for the evolution of hydrogen The method has all the desired characteristics of a commercial process:
No external source of power is required.
Dissolution of iron is negligible, as there is no external voltage source or oxidizing agent.
Economic rates of zinc dissolution can be achieved.
Zinc bearing solutions resulting from the process can be purified to allow production of a high-value zinc product.
The driving force for the galvanic dezincing of this invention is the potential difference between the electrode reactions for anodic zinc dissolution (equation (1) above; see Pourbaix, cited above),
E.sub.o =0.441-0.1182 (T/298)pH+0.0295 (T/298) log [ZnO.sub.2 -],
and for cathodic hydrogen evolution (equation (2) above),
E.sub.o =-0.0591 (T/298)pH,
where T is the temperature in Kelvin. For example, at an electrolyte temperature of 60° C. and a pH of 14.8 (corresponding to a caustic soda concentration of 250 gpl), the driving potential calculated from these expressions is 0.55 V.
As dezincing progresses, the total current I in amperes is determined by the equation
Driving Potential=IR+.sub.ηH2 +.sub.72 Zn
where
R is the resistance in ohms or the electrolyte between the cathode material and the scrap being dezinced,
.sub.ηH2 is the hydrogen overvoltage in volts on the cathode material, and
.sub.ηZn is the overvoltage in volts for zinc dissolution.
The overvoltage for zinc dissolution is small, typically less than 50 mV. Also, the hydrogen overvoltage on suitable active cathode materials is typically 75 mV, and is normally less than 100 mV at the current densities which would be used in dezincing. Both overvoltages depend on current density, but this effect can be neglected to a first approximation. Approximating the total of the anodic and cathodic overvoltages as 150 mV, a total of 400 mV is typically available to drive the flow of zinc dissolution current between the anodic scrap and the cathode material. This driving voltage is reduced somewhat when commercial galvanized coatings such as nickel-zinc or galvannealed (iron-zinc) are being stripped.
The cathodes which may be effectively used in this invention are the same class of materials which can be economically used in the alkaline electrolysis of water, as described for example by Janjua and LeRoy in "Electrocatalyst Performance in Industrial Water Electrolysers", Int. J. Hydrogen Energy, Vol. 10, No. 1, pp 11-19, 1985 and by Bowen et al. in "Developments in Advanced Alkaline Water Electrolysis", Int. J. Hydrogen Energy, Vol. 9, No. 12, pp 59-66, 1984. The active cobalt cathode material described by Janjua and LeRoy in U.S. Pat. No. 4,183,790 has also proven effective in short-term tests, although it loses activity on long-term use. The most successful cathode materials for long-term commercial use are high-surface-area nickel-based materials, for example of the Raney nickel type. High-surface-area cobalt-based materials, for example of the Raney cobalt type may also be used. Other suitable cathode materials are nickel molybdates, nickel sulfides, nickel-cobalt thiospinels and mixed sulphides, nickel aluminum alloys, and electroplated active cobalt compositions.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be disclosed, by way of example, with reference to the following examples which refer to accompanying drawings in which:
FIG. 1 illustrates the current flowing in an external circuit when various galvanized steel samples are coupled to two active cobalt cathodes;
FIG. 2 illustrates the dependence of the rate of zinc dissolution on electrolyte temperature;
FIG. 3 illustrates the effect of caustic concentration on the rate of zinc dissolution;
FIG. 4 illustrates the effect of zincate concentration in solution on the rate of zinc dissolution; and
FIGS. 5 and 6 illustrate the percentage and weight, respectively, of zinc removed as a function of time from various galvanized steel coupons mounted in a nickel basket in 7M NaOH electrolyte.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
In order to establish quantitatively the zinc dissolution rate by the method of this invention, experiments were performed as follows. A galvanized sheet sample was coupled through a 0.001-ohm resistor to sheets of the cathode material, which were mounted on either side of the galvanized sample. A recorder was connected across the resistor, and the electrode array wa immersed in the caustic electrolyte. FIG. 1 illustrates a typical record of the current which flows from the time of immersion to the time of complete zinc removal. In this case, the active-cobalt cathodes of U.S. Pat. No. 4,183,790 Were used. 11/2 inch ×6 inch galvanized samples were mounted immersed in 20% sodium hydroxide electrolyte to a depth of four inches, between active cathodes of equal size. Electrolyte temperature was 60° C. This experiment was repeated four times in the same 900 ml of electrolyte. The average dissolution rate in these experiments corresponded to a current of approximately 10 amperes, indicating a dissolution rate of 2.4 grams per square foot per minute. In each case, removal of the zinc coating was more than 99.5% complete within 5 minutes.
Example 2
Effect of Temperature--Experiments similar to those reported in Example 1 were carried out at 30° C., 45° C., 60° C. and 75° C. The electrolyte volume used was 330 ml.
The results are characterized by three parameters: the time required for complete zinc dissolution, the time required for dissolution of 50% of the zinc coating, and the current flowing 12 seconds after immersion of the electrode array.
The variation of each of these parameters with temperature is indicated in FIG. 2. For each experiment (at each temperature) a fresh NaOH solution was prepared, in order to eliminate effects due to build-up of the zincate concentration, which increased during each experiment from 0 to 4.6 gpl sodium zincate.
The sodium hydroxide concentration in these experiments was held constant at 200 gpl. This decreases slightly during each experiment due to hydroxide ion consumption in the formation of zincate ion, the net consumption being approximately 0.95 grams NaOH per experiment.
The results (FIG. 2) show that a temperature increase from 30° C. to 60° C. has a very strong effect in accelerating the zinc dissolution reaction. Further temperature increase to 75° C. also accelerates the rate, but by a decreased amount. This indicates that the optimum temperature of operation lies between 60 and 75° C.
Example 3
Effect of Caustic Concentration--Experiments were performed as described above for sodium hydroxide concentrations between 10 and 400 gpl. A fresh 900 ml electrolyte sample was used for each experiment, and the temperature was held constant at 60° C. The electrolyte was agitated by pumped recirculation. Results at 50 gpl NaOH and above are recorded in FIG. 3.
At a sodium hydroxide concentration of 10 gpl, the maximum dissolution current was 0.13 amperes and the dissolution reaction showed no indication of completion after 60 minutes. At 50 gpl NaOH the reaction rate was significantly increased, with total dissolution requiring 31 minutes. This rate increased rapidly as the NaOH concentration was increased to 200 gpl, but the beneficial effect of further concentration increases was relatively small. This suggests that the optimum concentration lies between 200 and 300 gpl.
Example 4
Effect of Zincate Concentration--It is well known that increasing concentration of zincate ions will tend to decrease the potential which is available to drive zinc into solution, when zinc is corroding in caustic electrolyte. For cost reasons, it is desirable to operate the method of this invention at the highest zincate concentration which is consistent with acceptable reaction rates.
Electrolyte samples of different zincate concentration were prepared by dissolving a calculated amount of zinc oxide in sodium hydroxide. Further sodium hydroxide was then added to achieve the desired NaOH concentration of 200 gpl. Experiments were performed at 60° C., and the electrolyte was agitated by pumped recirculation. The experimental arrangement was otherwise identical to examples 1 to 3 above.
Results are summarized in FIG. 4. Increased zincate ion concentration (expressed in FIG. 4 in terms of the contained zinc) depresses the rate of the zinc dissolution reaction.
The experiment performed at 75 gpl zincate (expressed in terms of zinc) suggests that there is an increased effect of agitation at high zincate levels. The electrolyte in this case was mechanically agitated, resulting in a faster reaction rate than was obtained at 50 gpl zincate (as zinc).
Example 5
Co-Dissolution of Iron--Iron is expected to be largely immune to corrosion during the zinc dissolution process, but some iron dissolution on oxidation could be expected after zinc removal is complete. To test this, thirty-nine sequential experiments were performed as described in the preceding examples, using the same 900 ml of caustic soda electrolyte. Analysis of the electrolyte at the conclusion of this experiment gave the following result:
______________________________________Element Concentration Loss Compared with Zinc Dissolved______________________________________Zinc 34.6 gpl 100%Iron 0.65 mgpl 0.0019%______________________________________
Thus, co-dissolution of iron is negligible when zinc is removed from galvanized scrap by the method of this invention.
Example 6
Effect of Galvanized Steel Type--The galvanic dezincing process can be used with any commercial grade of galvanized steel. The following experiments were performed with electrogalvanized steel sheet of 0.36 mm thickness having average zinc weight of 2.2% (SSC-14/A); galvannealed steel sheet of 0.32 mm thickness having average zinc weight of 0.93% (SSC-14/B); and hot-dipped galvanized sheet of 0.31 mm thickness having average zinc weight of 2.3% (SSC-14/C). 0.7 kg of each material was sheered into 1/4-inch square coupons which were placed into a rectangular basket fabricated from nickel mesh. In each case, the basket was immersed in 7 molar caustic soda electrolyte which was maintained at 20° C. Raney-nickel-type active cathodes (material NE-C-200 described in Int. J. Hydrogen Energy, Vol. 10, No. 1, pp 11-19, 1985) were arrayed on both sides of the basket, and connected electrically to it. Essentially complete zinc removal was achieved in each case. The proportion of zinc removed for each material as a function of time in these experiments is shown in FIG. 5, while the zinc weight removed is shown in FIG. 6.
This invention is of course not limited in any way to the conditions of the examples described above. For example, all of the examples have been carried out in a batch-wise fashion However, a continuous process could be envisaged, in which solution is continuously being passed from a tank in which zinc is being removed from galvanized scrap by the method of this invention to a tank in which zinc is being electrowon from the zincate solution. Methods of electrowinning zinc from zincate solutions are well known in the art, as described for example by C.C. Merrill and R.S. Lang in "Experimental Caustic Leaching of Oxidized Zinc Ores and Minerals and the Recovery of Zinc from Leach Solutions", U.S. Bureau of Mines Report of Investigations No. 6576, April 1964. In this way the method of this invention could be performed with the zincate level being held at an approximately constant level It would also allow the invention to be performed with no net consumption of caustic, as the overall reaction occurring in the electrowinning of zinc from zincate solution is
ZnO.sub.2 -+H.sub.2 O→Zn+1/2O.sub.2 +20H.sup.-. (4)
Combining this with the dissolution reaction (3) shows that the overall process is simply electrolysis of water, according to
H.sub.2 O→H.sub.2 +1/2O.sub.2. (5)
Similarly, the batch-wise addition and removal of galvanized scrap to the caustic solution is only one embodiment of this invention. A system could be envisaged in which the scrap is carried in and out of the solution on a continuous belt, with the residence time being calculated to give the desired degree of zinc removal. In all of these embodiments, electrical connection between the galvanized scrap and the cathode material can either be by direct contact within the aqueous electrolyte, or by external connection. Also, it is clear that this method could be practised in a wide range of electrolytes having pH's between 11 and 15.5. Sodium hydroxide and potassium hydroxide are, however, the most suitable candidates, because of their ready availability and low cost.
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A method of removing zinc from galvanized steel without substantial co-dissolution of substrate iron comprises immersing the galvanized steel in a caustic electrolyte solution, and electrically connecting the galvanized steel to a cathode material which is stable in caustic electrolyte and has a low hydrogen overvoltage.
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