description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
This invention relates generally to a garment bag of the type used to transport garments stored on separate hangers and more particularly to a garment bag where the hooks of the garment-bearing hangers extend through the upper end of the bag to provide a hand-grip when the bag is being transported, and to provide the point of suspension when the bag is stored, for example, on a closet rack. In the art, a small opening is generally provided centrally at the upper end of the bag for passage therethrough of the hanger hooks. Ideally the hooks are readily available to the person who wishes to transport the loaded bag. Unfortunately when the loaded bag has been lying flat, for example, on the rear seat of an automobile, or when a hanging loaded bag is lifted from the rack for purposes of hand-carriage, the hanger hooks, all or some, may slide through the top opening and become inaccessable to the user until the bag is opened.
Additionally when the bag is lifted by the hanger hooks, and, as described above, one or more hangers have slipped through the top opening, the unhooked garments and their hangers fall to the bottom of the bag. Aside from the inconvenience of retrieving the fallen garments, the garment bag, designed primarily as a covering for clothing, now bears the unintended weight load of the garments. This stresses the bag walls and top and can cause tearing which most frequently occurs proximate the central top opening.
What is needed is a garment bag which secures the separate and independent hangers and prevents the unintended slippage of the hanger hooks through the top opening.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, a foldable garment bag especially suitable for transporting garments is provided. A double strap is attached to the front wall of the bag adjacent to the top central opening. The first strap member, in surface contact with the front wall, loops over the bag top and is releasably attached to the back wall. C-shaped hanger hooks protrude from the bag compartment and each hook has a substantially horizontal segment extending over the first strap member. The second strap member, overlaying and attached at the front to the first strap member, loops over the horizontal segments of the hanger hooks and is releasably secured to the first strap member. Accordingly while the strap members are secured, the hanger hooks are restrained between the strap members and are prevented from slipping into the bag compartment or from moving substantially away from the top center of the bag. When the strap members are released the hangers are individually detachable from the garment bag in the conventional manner.
When the garment bag is folded, the first strap member is releasably attached near the bottom center of the folded bag, and in cooperation with lateral tabs maintains the folded condition of the bag while simultaneously restraining the hanger hook.
Accordingly, it is an object of this invention to provide an improved foldable garment bag having straps capable of preventing the hanger hooks from being laterally displaced or sliding into the bag interior.
Another object of this invention is to provide an improved foldable garment bag which is easily removed from a storage rack.
A further object of this invention is to provide an improved foldable garment bag which supports the folded bag centrally and laterally.
Still another object of this invention is to provide separable hangers with horizontal elements for cooperation with bag straps which secure the hanger to the garment bag.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a front view of the garment bag with hangers of this invention;
FIG. 2 is a rear view of the garment bag with hangers of FIG. 1;
FIG. 3 is a view taken along the line 3--3 of FIG. 2;
FIG. 4 is a partial perspective view of the garment bag of FIG. 1 in the folded condition; and
FIG. 5 is a view taken along the line 5--5 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the Figures, the garment bag 10 of this invention includes a front wall 12, joined peripherally to the rear wall 14. A permanent joining, as by stitching (not shown) between front wall 12 and rear wall 14, continuously extends generally from the top center 16 of the bag 10, along the right shoulder 18, as seen in FIG. 1, down the right side 20, across the bottom 22, and partially up from the bottom 22 along the left side 24. A zipper fastener 26 of extended length provides a reversible closure which extends upward from the termination 28 of the permanent joining, along the left side 24 and left shoulder 30 of the bag 10 and terminates substantially at the top center 16. The zipper slide element 32 is located adjacent the top center 16 when the zipper fastener 26 is in its closed condition. Accordingly when the zipper fastener 26 is fully opened, substantially an entire side 24 and one shoulder 30 are opened for the insertion or removal of garments on hangers in the known manner. The hangers are completely separable from the bag 10.
The garment bag 10 of this invention further includes a pair of tabs 34, symmetrically attached at the shoulders 18, 30 adjacent to the side joints 20, 24 and extending downward along the back wall 14. The male element 38 of a snap fastener is affixed to each tab 34, and mating female elements 40 of the snap fastener are alignedly attached to the front wall 12 near the bottom 22 of the garment bag 10. When the garment bag 10 is folded transversely (FIG. 4), the snap fastener elements 38 on the tabs 34, are releasably engaged with the fastener elements 40 on the front wall 12 to retain the bag 10 in the folded condition. The tabs 34 are fabricated from a flexible, durable material, e.g. leather, suited to carry the load imposed by the weight of the folded bag and its contents. Additional mating female elements 41 for the snap fastener are affixed to the back wall 14 in registration with the male elements 38 on the tabs 34 and are used to releasably grip the free ends of the tabs 34 when the bag 10 is not in a folded condition.
A central vertical strip 42 of material, e.g. cloth, leather, is attached, for example, by stitching, to the front wall 12 to provide reinforcement for, and to enhance the appearance of the bag 10.
A double strap assembly 44 is centrally attached to the front wall 12 proximate the top 16, for example, by stitching extended through the strap assembly 44, vertical strip 42 and front wall 12. The strap assembly 44 comprises a first flat, elongated, flexible, strap member 46 which is attached at one end 48 (FIG. 3) to the bag front wall 12, e.g. by stitching, as stated above. The other end 49 of the first strap member 46 is free for limited rotation about the fastened end 48 and includes a male snap fastener element 39 which when the bag is transversely folded releasably engages an aligned female snap fastener element 43 centrally attached to the front wall 14. Thus the folded-up portion of the bag 10 is supported by snap fasteners 38,40,39,43 at three locations, namely at the two lateral tabs 34 and at the central first strap member 46. When the bag 10 is extended to full length, the first strap member 46 is looped over the top of the bag 10 and connected to a female snap fastener element 45 located (FIG. 3) in registration on the back wall 14 of the bag.
The second strap member 50 of the double strap assembly 44 overlays the first strap member 46 and is affixed to both the first strap member 46 and the front wall 12 proximate the fixed end 48 of the first strap member 46. The other end 52 of the second strap member is free for limited rotation about the fastened end and includes a male snap fastener element 53 which releasably engages a female fastener element 54 on the outer surface of the first strap member 46. When both strap members 46, 50 are secured by the associated snap fasteners 39, 45, 53, 54, the strap members rest with substantial surface contact between them. However, the flexible quality of the overlayed strap members 46, 50 permits the hooks of hangers to be retained therebetween without permanent distortion of the straps 46, 50 as explained hereinafter.
The garment bag 10 is used in combination with separate clothing hangers 60 of generally conventional design, including downwardly sloping shoulder bars 62 connected at their center 63 and joined at the far ends 64 by a horizontal cross-bar 66. A hook 68, fabricated of stiff wire, is attached at the center 63 of the shoulder bar 62, and comprises a lower horizontal rod portion 70 (FIGS. 1, 2) extending away from the hanger center 63, and an integral rod portion 72 arching upward, and down, and passing over the center 63. Accordingly the hook 68 is substantially C-shaped and has a flat-bottomed profile as best seen in FIGS. 1 and 2.
In filling the garment bag 10 with hanging garments (not shown) the zipper fastener 26 is opened and the snap fastener elements on the double strap assembly 44 are opened. The clothing hanger 60 is removed from the interior of the bag 10 and the garments are suspended. Then the hanger 60 and associated garment are passed through the zippered opening with the C-shaped hanger hook 68 extending laterally above the bag shoulders 18, 30. The horizontal rod portion 70 of the hanger hook 68 passes over the center 16 of the bag 10. The first strap member 46 is looped under the horizontal rod 70 on the hanger hook 68 and attached to the rear wall 14 by means of the snap fastener 39, 45. Then the second strap member 50 is passed over the horizontal rod 70 on the hanger hook 68 and attached to the first strap member 46 by means of the snap fastener 53, 54. Thereby the hanger hook 68 is constrained vertically between the two strap members 46, 50 and laterally in one direction by the double strap assembly 44 and in the other lateral direction by the closed shoulder joint between front wall 12 and rear wall 14. The zipper fastener 26 is then closed by bringing the sliding element 32 up adjacent to the hook 68 at the top center 16 of the bag 10.
To place the loaded garment bag in a transversely-folded condition, the double strap assembly 44 is separated from the back wall 14 by opening the snap fastener 39, 45 engaging the first strap member 46. The hanger hook 68 remains secured between the two strap members 46, 50. The free ends of the tabs 34 are also separated from the back wall 14 by release from the female snap elements 41. The bag is then folded so that the snap fastener elements on the tabs 34 and first strap member 46 are in registration with the snap fastener elements 40,43 on the front wall 12. Pressure on the snap fasteners, in the known manner, releasably joins the folded-up bag portion to the upper bag portion. The loaded bag is carried, or suspended from a storage rack, by the C-shaped hooks 68. It should be noted that in using the double strap assembly 44, the stresses caused by the weight of folded garments are transmitted to the hanger hook 68 and thence via the strap members 46, 50 to the back wall 14 of the bag and to the reinforcing strip 42. Thus stresses on the zipper 26 and bag shoulders 18, 30 which might in some circumstances damage the bag 10 are relieved and directed to an area which is conveniently reinforced.
It should be obvious that the steps in using the garment bag 10 of this invention are not restricted to the order presented above. For example, the zipper may be closed before the strap members are fastened. The end result is unchanged by the sequence of steps used to constrain the hanger hook 68.
In alternative embodiments of this invention, the zippered opening is not limited to one bag side and a shoulder, but may extend substantially around the entire bag periphery. In another embodiment of this invention, the zippered opening may be located entirely in one wall, front or rear of the garment bag, and extending vertically, diagonally or in any direction and position suited to the insertion therethrough of hangers bearing garments
It should further be understood that whereas zipper and snap fasteners have been described above in association with the garment bag 10 of this invention, other closures and fasteners, e.g. buttons, hooks, may be utilized in alternative embodiments.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A foldable garment bag has hooks of separable hangers extended externally from the upper end, and includes a double strap and tabs attached to the bag. One strap member passes beneath the hanger hooks and holds the folded-up portion of the bag; the other strap member loops over a horizontal, linear portion of each hanger hook and constrains the hangers to the bag. The lateral tabs cooperate with the double strap to maintain the folded condition of the bag. | 0 |
BACKGROUND OF THE INVENTION
In high snow load regions, roof top snow can melt into water due to escaping heat from the structure's interior or thermal radiation from the sun. When this water drains to the colder overhang or other colder roof surfaces the water can refreeze creating an ice dam. Ice dams can also form in the valley between adjoining roof surfaces or next to roof protrusions such as chimneys, dormers or second story structures. A continuously heated drain path, including heated gutters and down spouts, ensure the water is drained away from the structure's foundation.
These ice dams can prevent additional snow melt water drainage and standing water is formed above the ice dam. Most slanted roofs are designed to shed moving water like an umbrella, not to hold standing water like a swimming pool. This standing water can penetrate a standard roof and enter the structure causing interior damage, mold, mildew and electrical issues. If this water is allowed to re-freeze, the change-of-state expansion can cause major structural damage.
To provide a heated drain path though the ice dam, the state of the art for professional installations utilizes self-regulating electrical heating cable that increases the heat output per foot when the cable is in direct contact with ice and snow. When the drainage path around the cable is established, the air pocket acts like a storm window and greatly reduces the thermal conduction between the heating cable and the ice and snow. As the electrically semi-conductive cable core heats up, the electrical resistance between the electrical bus wires increases and the electrical wattage used per foot decreases. A typical self-regulating ice and snow melt cable can create a load of 24 watts per foot in ice and snow at −10° F. but drops to about 6 watts per foot in ambient air at 32° F. So the air pocket around the cable becomes an important variable in the system and product design.
Increasing the size of the melt path has been the goal of the industry for many years. A single run of cable provides about a two inch wide drain path. A zig-zag placement of the cable provides a wider coverage area but ice can form between the zig and the zag and the additional cable length adds cost and requires more electrical power.
Embedding the cable in a fixed width cavity inside a thermally conductive metal panel system works quite well to increase the size of the melt path, which is the goal. Some heavy weight extruded panels are offered that have a high fixed thermal mass, ensuring maximum heat sinking and electrical power usage from the self-regulating heating cable. However, over time the thermal expansion and contraction of the cavity size of any current panel design reduces the contact area between the cable and the metal. A very small thermal air gap can reduce the self-regulating cable's heat output and the temperature of the metal panel dramatically.
BRIEF SUMMARY OF THE INVENTION
Maintaining a long term, thermally conductive contact between the self-regulating heating cable and the snow melt metal panel or metal surface is the main focus of this disclosure. System cost and energy efficiency are also important. This invention uses low cost sheet metal panels with spring loaded members in the cable cavity that ensures firm, long term contact with the heating cable. To address energy efficiency, the variable thermal mass of light weight sheet metal becomes a factor. The light weight sheet metal panel system only uses large amounts of electrical power when loaded down with snow and ice which increases the thermal mass of the panel. When the snow and ice have drained away, the variable mass of the cleared panel decreases dramatically and the self-regulating cable current consumption goes down, saving energy.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows an exploded view of a three element, multi-segment or bellows type of heating cable retention system that firmly presses the cable against the bottom of a metal drip edge usually found on raised seam metal roofs.
FIG. 2 shows the compressed view of a two element bellows system pressing the heating cable to the bottom of the metal drip edge and the mounting screw that is used to hold the retention strip in place.
FIG. 3 shows a two part system that is required for roof edge heating for roofs with non-thermally conductive materials such as asphalt composite shingles. The top mounted metal slip sheet (or snow slide) is heated from the bottom by the heating cable which is held in place by the multi-segment retention system.
FIG. 4 shows a one piece panel system with a multi-segment cavity to retain the heating cable. This one piece panel is an alternative to the two piece panel shown in FIG. 3 .
FIG. 5 shows the mounting of the one piece panel on a shingled roof using a self-drilling construction screw.
FIG. 6 shows the one piece panel layout on a typical shingled roof. Also shown are three transitional brackets.
FIG. 7 shows a close up of the transition bracket that is used to retrain both ends of each panel. To avoid roof penetration with the roof top screw retention shown in FIG. 5 , these transition brackets are attached to the structure with screws into the fascia that are protected by the roof edge overhang.
FIG. 8 shows a one piece heated panel placed under a corrugated, rib or raised seam metal roof to provide a heated roof drip edge.
FIG. 9A shows a close-up of the one piece panel with the multi-segment cable retention cavity system for a corrugated or rib panel metal roof.
FIG. 9B shows a transition panel for the panels shown in FIG. 9A .
FIG. 10 shows a heating panel with a front loading multi-segment heating cable retention cavity. This is an alternative to the other panels that have a rear loading cavity.
FIG. 11 shows the front loading design offers a shorter overhang from the roof edge and may provide for easier cable removal and replacement.
FIG. 12 shows a cross sectional view of a roof top heated utility panel with a multi-segment cable retention cavity.
FIG. 13 shows the cross sectional view of the utility panel with the heating cable in place within a multi-segment cable retention cavity.
FIG. 13A shows an extended width panel with a vertical member ( 131 ).
FIG. 14 shows the three dimensional view of the long utility panel with a multi-segment cable retention cavity. These panels can be placed around and above roof penetrations such as chimneys, dormers or second story structures to provide a heated drain path in areas subject to snow retention. They can also be placed in valleys where different roofs converge.
FIG. 15 shows a cross sectional view of a wider utility panel with a multi-segment cable retention cavity.
FIG. 16 shows two runs of heating cable installed in the wider panel for applications requiring a wider roof top or valley melt path.
FIG. 17 shows an exploded view of the components used to provide a heated drainage path on either side of the raised seam on a metal roof. The multi-segment retention rail presses the heating cable to the metal roof which in turn acts like a heating panel and provides a heated drainage path for the snow melt water. The seam clamp with rounded inside corners and set screw are used to attach the retention rail to the raised seam.
FIG. 18 shows the assembled components.
FIG. 19 shows the lower two part flashing components that fit together to form a raised seam flashing assembly that can be place in problem areas of the roof. This raised seam assembly can then be fitted with the components shown in FIG. 17 .
FIG. 20A shows the top view of a heating cable retention system used on a raised seam roof at the top of the cable run and the top view of the cable retention rail as shown in FIG. 17 .
FIG. 20B shows the side view of FIG. 20A with the multi-segment retention rail pressing the heating cable to the metal roof top.
FIG. 21 shows the various roof top panel placement configurations.
DETAILED DESCRIPTION OF THE INVENTION
In high snow load regions, snow melt water tends to refreeze on the colder lower areas of the roof. Higher on the roof the snow is exposed to the heat escaping from inside the structure. Top floor ceiling penetrations for overhead lights and ventilation duct work can create massive heat loss from inside the structure to the attic space which then heats the bottom side of the roof deck which can melt the snow on the top of the roof deck. Solar heating of the snow on the upper part of the roof also contributes to snow melt water in areas not shaded by trees. This snow melt water usually stays under the snow, much like the effect seen in a glass of ice water—the solid snow and ice float on top of a layer of water. This water then drains down the roof, under the snow and ice, and tends to re-freeze on the colder roof surface over the unheated roof overhang. This can lead to large ice formations at the roof drip edge which can fall to the ground causing damage to property and injury to people.
Colder roof surfaces can also be found where snow depth increases, for example in the valley between adjoining roof surfaces or behind roof protrusions like chimneys or second stories. The lower roof surfaces are sometimes shielded from solar heating due to the angle of the sun in winter or by trees planted too close to the structure. When this moving water is exposed to the colder roof surfaces it will sometimes refreeze creating what is called an ice dam. This sold ice formation builds in size and height and prevents continued drainage of the snow melt water coming down the roof. The standing water increases in depth and can leak back under the shingles or other roofing material into the interior of the structure. Normal roofs are designed to shed moving water like an umbrella, not to hold standing water like a swimming pool.
When this standing water leaks into the structure, it can cause mold, mildew and damage to electrical systems. It can leak through the ceiling and destroy furniture, carpet and other household goods. Often times this water re-freezes and the change-of-state expansion has the power to separate structural members that are nailed together or to destroy the glue or sealing bond between surfaces. If the water is permitted to collect around the structure's foundation and refreeze, the concrete foundation can crack and leak water into the basement. This structural damage may not be recognized for a period of time. The first priority under these conditions is to provide a continuously heated drain path for the snow melt water to drain off the roof, into a heated gutter and downspout and away from the structure's foundation.
Contrary to common belief, best practice is to provide a heated drain path for the snow melt water rather that to use the extra electrical energy required, due to the latent heat of fusion (hidden heat required for change of state from solid to liquid) to melt ice once it is formed. This suggests that a system using self-regulating heating cable powered 24 hours a day is more energy efficient than using a timer to turn off the system a night which allows the snow melt water to refreeze only to use additional electrical energy to melt the ice the next day so it can drain from the roof structure.
Over the years, many systems have been developed to deal with these drainage issues. The miner's shacks of the 1800's had metal slip sheets or snow slides placed at the roof edge, around the perimeter of the building. When these metal panels were heated by the sun and the up-roof snow melt drainage water, the snow and ice would lose adhesion and slide to the ground. Electrical constant-current heating cables were introduced in the mid 1900's and are still used today to provide a heated melt path for snow melt water.
Self-regulating heating cables were introduced in the late 1900's that had a semi-conductive carbon infused plastic core between two electrical buss wires that would lower the electrical resistance between the buss wires as the core became colder, and increase resistance between the buss wires as the core warmed up. This was a major energy saving improvement. The cable would use more electrical energy per foot the colder the core became. As the core warmed up, the electrical resistance between the buss wires would increase and the electrical energy used per foot would decrease.
These self-regulating heating cables would be placed on the roof surface and in the gutters and downspouts to create a heated drainage paths for the snow melt water until it was safely drained away from the structure's foundation.
Combining self-regulating heating cable with the slip sheets of the 1800's was the next step in the evolution. Some slip sheets were made from heavy extruded aluminum to present a high thermal mass heat sink to the self-regulating heating cable. Later, lower cost sheet metal slip sheets combined with self-regulating heating cable were introduced.
But both types of slip sheets had the same type of fixed size cavity for the self-regulating heating cable. A tight contact between the heating cable and the metal panel is very important for thermal conductivity. Any air space acts like thermal insulator, similar to a storm window. With this partial thermal insulation, the self-regulating heating cable core warms up prematurely and produces less heat output.
The heavy metal extrusion panel had a fixed size cavity that did not offer a tight flexible contact to the heating cable and a sheet metal cover that sometimes made cable replacement difficult. Over time, the thermal expansion and contraction of the sheet metal panel systems would cause metal fatigue and the cavity size would increase. Sometimes the heating cable would fall out of the cavity. In both cases, thermal conduction between the metal panel and the heating cable would degrade, the cable core would warm up and the heat output of the cable would decrease.
The inventions disclosed herein are an improvement to the previous designs by offering a multi-segment spring loaded or bellows type of metal to cable thermal contact that is flexible and not subject to metal fatigue. The multiple-segments act like leaf springs along the length of the cable raceway. Ease of cable insertion, long term cable retention and high thermal conductivity combined with the low cost advantage of sheet metal is the next generation of this type of product disclosed in this invention.
FIG. 1 illustrates a three part multi-segment 13 spring loaded or bellows type of retention strip 14 used to retain a tight contact between the heating cable 12 and the bottom of a metal drip edge 11 . The extra element added in the retention strip 13 in FIG. 1 is sometimes required to mate to a roof edge that is very wavy or exhibits “oil canning” in the parlance of the trade. The kick-out 15 prevents water wicking into the space behind the strip 14 . FIG. 2 shows the installation of a two part element spring strip with the attachment screw 23 . The metal bends 21 and 22 ensure tension on the elements that bow and act as leaf springs. A small amount of the cable is exposed to conform to some local interpretations of Article 426 of the National Electrical Code. These strips can be made of copper, steel or aluminum sheet metal by bending on a brake or using a roll forming machine.
FIG. 3 shows the slip sheet 33 slid under the second or third shingle 31 but on top of the lower shingles 32 that is on top of the roof deck 34 . This provides a heat conductive metal surface up the roof that is heated by the self-regulating heating cable 12 . The multi-segment retention strip 14 is held in place by the retention screw(s) 23 . Kick outs 35 , 15 are provided for the slip sheet panel 33 and for the retention rail 14 .
FIG. 4 shows a rear loaded multi-segment 43 , spring loaded heating cable cavity 42 that holds the heating cable 12 . As shown in FIG. 5 , the panel 41 can be held in place with the attachment screw(s) 51 or glued in place at the screw location. For new construction the screw may be preferred. For retro-fit applications, glue eliminates having to bend the shingle up to insert the screw. This presents a clean look at the drip edge, but hides the cable which may be allowed depending on the local interpretation of Article 426 . Removal and replacement of the cable requires lifting the panel. This type of one part product does not vary with roof pitch, unlike the two part configuration shown in FIG. 3 . This allows for a standardized product that is appropriate for the inventoried retail sales channels.
FIG. 6 shows the transition panels 61 which provide additional retention for the heated panels 41 . FIG. 7 shows the cut-away view of the transition panel 61 with a water drainage hole 74 . The larger cavity 72 transition panels 61 mount around the bottom edge of both ends of the heated panels 41 to hold them in place and is attached to the fascia with mounting screws 75 . This type of retention holds the panels securely in place without the roof penetrating screw(s) 51 as shown in FIG. 5 . The kick out 76 prevents water wicking behind the transition panel 61 . The final bend 73 location is determined by the distance back to the front fascia and can be ordered to this dimension or the bend can be formed during installation.
FIG. 8 shows a rear entry heating panel 82 with a multi-segment heating cable retention cavity that installs under a metal corrugated, rib or raised seam roof 81 . A cable retention strip 14 as shown in FIG. 1 could be used, but the larger surface area between the cable and the panel and the bottom of the metal roof provides more thermal conductivity than having only the narrow cable in contact with only the bottom protrusion area of a wavy roof 81 . It has been found that trying to bend the cable up and down into the cavities of the corrugations is very difficult. FIG. 9A shows the cross sectional close-up detail of the heating cable 12 as it enters the multi-segment heating cable retention cavity 91 . FIG. 9B shows the narrow transition cover panel with the larger cavity 92 and drain hole 93 that slides over the gaps between the longer panels shown in FIG. 9A .
FIG. 10 shows a front entry panel 101 with a multi-segment 103 heating cable 12 retention cavity 102 . FIG. 11 shows the installation of the panel 101 under the second shingle of a roof with very large or thick shingles 31 , 32 . For standard shingles the panel would cover the bottom two shingles as shown in FIG. 5 . The retention screw(s) 51 mount the panel on top of the lower shingle 32 which is on top of the roof deck 34 . Instead of the retention screw(s) 51 , an appropriate adhesive may be used in retro-fit applications. Although more expensive to make because of the additional bend, this front entry product offers a shorter protrusion from the shingle edge which may be helpful in situations where the water drainage from the roof over the extended rear entry heated panel over-shoots the gutter. Cable replacement may be easier from the front and the partial cable exposure may be required by local inspection authorities. The same multi-segment heating cable cavity ensures a tight contact of the cable to the metal and long term retention not subject to metal fatigue issues.
FIGS. 12 and 13 shows a utility panel with a multi-segment heating cable 12 retention cavity 131 that can be screwed or glued in place under or on top of shingles or other roofing materials in the roof valleys. FIG. 13A shows a vertical bend 132 that allows the heating cable raceway to be used as a flashing against a vertical surface such a dormer, second story or chimney. In all cases the multi-segment heating cable 12 retention cavity 131 provides long term retention of the heating cable 12 and maximum thermal heat transfer from the heating cable to the metal raceway. FIG. 14 shows the cross-sectional view of the panel that would typically be about five feet long.
FIGS. 15 and 16 show a wider panel 150 that is typically over eight inches wide for applications that require a larger heated surface area and uses multiple runs of self-regulating heating cable 12 . Once again, the same multi-segment heating cable retention cavity ensures a tight thermal contact of the cable to the metal and long term retention not subject to metal fatigue issues. The center bowing effect 161 of the extra segment, like an automotive leaf spring, presents a slightly curved surface that contacts both heating cables 12 for a tight fit.
FIGS. 17 and 18 illustrates a rather complicated system to heat the metal surface of a raised seam roof to provide a heated drain path for snow melt water. A raised seam roof should not be penetrated by screws and the sliding snow can present hundreds of pounds of force to any projections from the roof surface. Some of the current systems use cable retention clips glued the metal surface of the roof. Due to the thermal stress and the UV radiation of the sun, these systems have proven to be unreliable. In this disclosure, raised seam clamps 171 with a side mounted set screw 172 are used in combination with a modified spring loaded retention rail 173 , similar to the retention rail 14 in FIG. 1 . This upside down version rail 173 is used to create a multi-segment, spring loaded surface 174 that pushes down on the heating cable creating a tight cable cavity for the self-regulating cable 12 . The two inside corners 181 and 182 of the extruded metal clamp are rounded to distribute the clamping force across a larger area and provide a larger cavity for the several layers of sheet metal.
FIG. 19 shows an additional invention of a two part raised seam flashing assembly. On the left is the female sheet metal flashing 191 and on the right is the male sheet metal flashing 192 . When mated, a raised seam flashing assembly is created that can be combined with the modified spring loaded retention rail 173 system shown in FIGS. 17 and 18 to create a multi-segment, spring loaded heating cable cavity for the self-regulating cable 12 . This assembly can be attached to the roof surface with adhesives or screws if the roof structure allows penetration.
FIG. 20A and FIG. 20B show the top and side views of the heating cable retention system for a raised seam metal roof at the top of the cable run. The left side raised seam 201 , seam clamp 202 and top machine threaded bolt 203 hold the padded cable retention loop 204 at the top of the heating cable 205 run. Once the cable is secured at the top of the run, the rounded rectangle shaped heating cable is twisted 90° and lays flat under the modified spring loaded retention rail 207 , pressing the heating cable 205 against the top surface of the metal roof 209 . This heating effect turns the metal roof surface into a heated raceway to provide the snow melt water a heated drainage path.
FIG. 21 shows the various roof top panel placement configurations. On the left is a conventional shingled roof 211 with a dormer, on the right is a raised seam metal roof 212 . The shingled roof is shown with heated panels 213 around the dormer and at the roof drip edge 217 . A heated utility panel 214 is used in the valley between the roofs. On the metal roof 212 , the multi-segment retention rails 215 hold the heating cable to the top roof surface. The top-of-run heating cable loop retentions 216 are shown. The under the metal roof drip edge retentions 218 are also shown. Not shown are the heated gutters and downspouts, covered by prior art, that are normally required to complete the heated drain path for the snow melt water to drain away from the structure's foundation.
Certain embodiments of the invention have been described; however, they are examples only, and not intended to limit the invention recited in the claims. Variations and safety features which will be obvious to those of ordinary skill in the art, such as the use of any weather tolerant heating cable, and avoiding damage to the cable covering by bending any sharp edges of the spring member away from the cable, fall within the scope of the following claims. | If roof top snow melt water is allowed to refreeze on the colder areas of the roof, an ice dam can be formed. A heated drainage path ensures this water is drained away from the structure's foundation. The various sheet metal raceway products disclosed contain spring-like folded members to securely press against the self-regulating heating cable, thereby maximizing the thermal conduction between the heating cable and the sheet metal raceways. The spring-like members of the raceways ensure a tight thermal contact to heating cables of different thicknesses. The spring-like members compensate for metal fatigue to provide a longer useful life of the installed system. The system also allows easy end of life replacement of the heating cable. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] None.
BACKGROUND OF THE INVENTION
[0003] Demand for storage space in modern homes and other buildings, and in particular, in garages, is at a premium. These spaces can become cluttered and messy in the absence of organizational tools to help utilize available space. As people accumulate ever increasing quantities of outdoor equipment, the need to organize these spaces becomes more acute.
[0004] One outdoor item which has contributed to the need for increased organization is the portable ice house. The use and popularity of portable ice houses has grown over the last decade. New designs and technological advancements in portable ice houses make them more user friendly. The downside of these designs, however, is that they typically require a significant amount of storage space, especially when stored flat.
[0005] In light of the foregoing, there remains a need for a device that can utilize unused space, for example, in one's garage.
[0006] The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
[0007] All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
[0008] Without limiting the scope of the invention, a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
BRIEF SUMMARY OF THE INVENTION
[0009] In some embodiments, the invention is directed to a storage lift assembly which comprises a base, a plurality of brace members, an electric winch, a plurality of rollers, a plurality of pulleys, and a first cable. The brace members are mechanically linked to one another and to the base. Further, in some embodiments, the electric winch extends from the base. And, the rollers are rotatably attached to the base. In some embodiments, the pulleys are connected to the brace members and the first cable is routed from the electric winch over at least one of the pulleys. The first cable contacts one of the rollers between the electric winch and the pulley.
[0010] In some embodiments, the storage lift assembly further comprises a second cable. The second cable extends from the electric winch and over at least one of the pulleys.
[0011] In some embodiments, each of the cables has two free ends. At least one of the free ends of each cable has a chain attached thereto.
[0012] In some embodiments, each of the cables is connected to a chain via a karabiner.
[0013] In some embodiments, the plurality of rollers comprises a first pair of rollers and a second pair of rollers.
[0014] In some embodiments, the plurality of pulleys comprises a first pair of pulleys and a second pair of pulleys.
[0015] In some embodiments, the rollers of the first pair of rollers are spaced at a distance R 1 and the rollers of the second pair of rollers are spaced at a distance R 2 . In some embodiments, the pulleys of the first pair of pulleys are spaced at a distance P 1 and the pulleys of the second pair of pulleys are spaced at a distance P 2 . In some embodiments, P 1 >R 1 and P 2 >R 2 .
[0016] In some embodiments, the electric winch is attached to a control box.
[0017] In some embodiments, the electric winch comprises a direct current motor.
[0018] In some embodiments, the invention is directed to a storage lift kit which comprises:
[0019] a base;
[0020] a brace member;
[0021] an electric winch;
[0022] a plurality of rollers;
[0023] a plurality of pulleys;
[0024] at least one cable; and
[0025] a control box for operating the electric winch.
[0026] In some embodiments, the storage lift kit further comprises a plurality of karabiners.
[0027] In some embodiments, the storage lift kit further comprises an instruction manual for assembling the storage lift.
[0028] In some embodiments, the storage lift further comprises a chain. In some embodiments, the invention is directed to a storage lift which comprises a base, a plurality of brace members, an electric winch, and a plurality of rollers. Further, in some embodiments, the storage lift comprises a rolling guide, a plurality of pulleys, and first and second cables. In some embodiments, the brace members include central brace members and outboard brace members. The brace members are rigidly connected to one another and the central brace members are attached to the base. In some embodiments, the electric winch extends from the base. In some embodiments, the rollers include a first pair of rollers and a second pair of rollers. The rollers are rotatably attached to the base and extend orthogonally from the base. In some embodiments, the rolling guide is attached to the base and is parallel to the base. In some embodiments, the pulleys are connected to the outboard brace members.
[0029] In some embodiments, the first cable has a first section and a second section. The first section of the first cable is routed from the electric winch, between the rollers of the first pair of rollers, and over one of the pulleys. The second section of the first cable is routed from the electric winch, between the rollers of the first pair of rollers, and over another one of the pulleys.
[0030] In some embodiments, the second cable has a first section and a second section. The first section of the second cable is routed from the electric winch, over the rolling guide, between the rollers of the second pair of rollers, and over another one of the pulleys. The second section of the second cable is routed from the electric winch, over the rolling guide, between the rollers of the second pair of rollers, and over another one of the pulleys.
[0031] In some embodiments, the electric winch is situated between the first pair of rollers and the second pair of rollers.
[0032] In some embodiments, the invention is directed to a storage lift that is used in combination with a storage facility. The storage lift is attached to the storage facility. In some embodiments, the storage facility comprises a garage.
[0033] In some embodiments, the storage lift is used in combination with an ice house, with the first and second cables being attached to the ice house.
[0034] In some embodiments, the storage lift further comprises a battery box attached to the central brace members.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 shows a perspective view of an embodiment of the garage-storage lift assembly and an ice house in a storage-ready configuration.
[0036] FIG. 2 shows a detailed perspective view of a portion of the garage-storage lift assembly of FIG. 1 .
[0037] FIG. 3 shows an embodiment of the roller assembly 36 .
[0038] FIG. 4 shows a perspective view of the garage-storage lift assembly of FIG. 1 .
[0039] FIG. 5 shows an end view of an ice house, in a storage-ready configuration, that is suspended by the garage-storage lift assembly of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0040] While this invention may be embodied in many different forms, there are described in detail herein specific embodiments. This description is an exemplification of the principles of the invention and is not intended to limit it to the particular embodiments illustrated.
[0041] For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated.
[0042] An assembly for lifting and storing an ice house 24 or other item is herein disclosed. Shown for example in FIG. 1 , the assembly 10 comprises a base 12 , a plurality of brace members 14 , an electric winch 16 , a plurality of rollers 18 , a plurality of pulleys 20 , and one or more cables 22 .
[0043] As used herein, the term “ice house” is used herein to refer to such a structure regardless of configuration. For example, the ice house can be assembled, disassembled, folded, prepared for storage, or ready for use.
[0044] Generally, the brace members 14 are rigidly mounted to the ceiling of a garage or other structure so that the ice house 24 can be raised via the assembly 10 . Additionally, attached to the base 12 are the rollers 18 and pulleys 20 . Optionally attached to the base 12 are the brace members 14 .
[0045] In some embodiments, the assembly 10 comprises outboard brace members 14 a and central brace members 14 b. The ice house 24 is generally suspended from the outboard brace members 14 a while the central brace members 14 b support the electric winch 16 .
[0046] Turning to FIG. 2 , the base 12 is shown attached to the central brace members 14 b. Further, in some embodients, the rollers 18 and electric winch 16 are attached to the base 12 . In some embodiments, the rollers 18 extend orthogonally from the base 12 . The rollers 18 guide the cable 22 between the winch 16 and the pulleys 20 .
[0047] As shown, for example in FIG. 3 , in some embodiments, the rollers 18 comprise a first pair of rollers 18 a and a second pair of rollers 18 b. In some embodiments, the rollers 18 are attached to the base 12 via bolts 32 on which nuts 34 are threaded to secure the bolts 32 to the base 12 . In some embodiments, a plate 28 is located at the end of the bolts 32 . The rollers 18 are located between the plate 28 and the base 12 , with washers 30 and nuts 34 disposed on the ends of the rollers 18 , as desired. Further, in some embodiments, the rollers 18 are secured on the bolts 32 such that they are permitted to rotate. For example, a nut 34 is threaded onto the bolt 32 but is not fully tightened against the bolt 32 . Moreover, to secure the roller assembly 36 to the base 12 ( FIG. 3 ), another nut 34 is threaded onto the bolt 32 to sandwich the base 12 between the head of the bolt (not shown) and the nut 34 . In some embodiments, a threaded rod is used in place of bolts 32 .
[0048] The rollers 18 can be made from any suitable material. In some embodiments, the rollers 18 are made from a metallic material, for example steel. Polymeric materials, rubber, alloys, and composite materials may also be suitable.
[0049] With further regard to FIGS. 2 and 3 , in some embodiments, the base 12 has attached thereto a rolling guide 38 . The rolling guide 38 positions the cable 22 away from the base 12 and aligns it with the electric winch 16 ( FIGS. 1 and 2 ). In some embodiments, the rolling guide 38 is parallel to the base 12 . Further, it will be appreciated that in some embodiments, a rolling guide 38 is necessary on only one side of the electric winch 16 as the cables 22 extend from opposing hemispheres of the electric winch 16 .
[0050] In this regard, and with further reference to FIGS. 1 and 3 , in some embodiments, the assembly 10 comprises two cables 22 , a first cable 22 a for lifting one side of the ice house 24 and a second cable 22 b for lifting the other side of the ice house 24 . In some embodiments, for example as shown in FIG. 2 , the first cable 22 a emanates from the top side of the electric winch 16 while the second cable 22 b emanates from the bottom side of the electric winch 16 . This configuration allows the electric winch 16 to raise the ice house 24 , simultaneously acting on the first cable 22 a and the second cable 22 b.
[0051] In some embodiments, the first cable 22 a comprises a first section 22 a ′ and a second section 22 a ″. Further, the second cable 22 b comprises a first section 22 b ′ and a second section 22 b ″. The cable sections, 22 a ′, 22 a ″, 22 b ′, and 22 b ″, are defined as the length of cable extending from the electric winch 16 , with the electric winch 16 being the divider between the respective sections.
[0052] Turning to FIG. 4 , in some embodiments, the rollers 18 of the second pair of rollers 18 b are spaced apart from one another at a distance R 2 . Further, the rollers 18 of the first pair of rollers 18 a are spaced apart from one another at a distance R 1 . In some embodiments, R 1 is equal to R 2 .
[0053] In some embodiments, the pulleys 20 comprise a first pair of pulleys 20 a and a second pair of pulleys 20 b. The pulleys 20 of the first pair of pulleys 20 a are spaced apart from one another at a distance P 1 while the pulleys 20 of the second pair of pulleys 20 b are spaced apart from one another at a distance P 2 . In some embodiments, P 1 is equal to P 2 . Further, in some embodiments, P 1 is greater than R 1 and, in some embodiments, P 2 is greater than R 2 . In this way, the rollers 18 direct the cables 22 from the wider spaced pulleys onto the electric winch 16 .
[0054] In some embodiments, the pulleys 20 are attached to the outboard brace members 14 a by way of eye bolts 40 . Moreover, in some embodiments, the brace members 14 are secured to the garage ceiling by way of lag bolts.
[0055] With reference to FIG. 5 , in some embodiments, the cables 22 have chains 42 attached thereto. Each of the cables 22 has two free ends 58 which, in some embodiments, are attached to the chains 42 . In some embodiments, the chains 42 are attached to the cables 22 via a karabiner or spring snap 44 . Although shown with a karabiner 44 in FIG. 5 , other types of hooks, for example s-hooks, or other attachments could also be used. It is also within the scope of the invention for the cable 22 to be hooked directly to the chain 42 .
[0056] As illustrated via FIG. 5 , the ice house 24 can be leveled by way of chains 42 and karabiners 44 . The chains 42 are secured to the ice house 24 using fasteners 46 . In some embodiments, the fasteners 46 comprise bolts that are inserted through holes in the ice house 24 . Desirably, washers 30 are used to distribute the load. As shown in FIG. 5 , a washer 30 is placed near the head of the fastener 46 and the fastener 46 is then disposed through one of the last links, desirably the last link, of the chain 42 . Thereafter, another washer 30 is added and the fastener 46 is pushed through the hole in the ice house 24 . A washer may be added to the end of the fastener protruding into the ice house 24 and a nut threaded onto the end of the fastener 46 and tightened. In some embodiments, it may be necessary to drill holes in the desired location of the ice house 24 .
[0057] As further shown in FIG. 5 , the assembly 10 further comprises a control box 48 . In some embodiments, the control box 48 comprises a hand held remote. The control box 48 is connected to the electric winch 16 and has an up button and a down button or other switch or toggle for directing the winch to wind or unwind the cable 22 as desired.
[0058] In some embodiments, the assembly 10 has a safety line 50 connected to the chain 42 and the brace member 14 . The safety line 50 provides added security in the event of component failure, for example in the cable 22 or electric winch 16 . In some embodiments, the safety line 50 comprises a braided wire. Other materials and configurations are also suitable, for example rope or chain. In some embodiments, the safety line 50 has a spring snap, for example a slide-bolt spring snap 52 , as shown.
[0059] In some embodiments, the electric winch 16 comprises a direct current (D/C) motor. In some embodiments, the DC motor is a 12V type motor that can be operated off of a car battery. Alternatively, the electric winch can use an alternating current (A/C) motor, for example 110V.
[0060] In some embodiments, a battery 56 , for example 12V, is located in a battery box 54 , for example as shown in FIG. 2 . In some embodiments, the battery box 54 is attached to the central brace members 14 b. Other locations are suitable as well. In some embodiments, the electric winch is powered by an A/C to D/C converter. More generally, any suitable power supply may be used.
[0061] In some embodiments, the assembly 10 comprises a limit switch that automatically stops the electric winch 16 once the ice house 24 has reached a predetermined height.
[0062] In some embodiments, the brace members 14 are drilled to be compatible with both 18 inch and 24 inch truss-spacing. Additionally, in some embodiments, the brace member 14 can be drilled to be compatible with 16 inch, 18 inch, and 24 inch truss-spacing, or any combination of common truss-spacing(s).
[0063] In some embodiments, the components of the assembly 10 are sold in a kit, desirably together with an instruction manual for assembling and using the storage lift.
[0064] It will be appreciated that the assembly 10 can be used with a variety of ice house types, including popular brands. In this way, the assembly 10 is universal. Further, although herein described with reference to ice house 24 , the skilled artisan will appreciate that the assembly 10 can be used with a variety of other products, for example kayaks, boats, boxes, cargo carriers, temporary dwelling, and the like.
[0065] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. The various elements shown in the individual figures and described above may be combined or modified for combination as desired. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”.
[0066] Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
[0067] This completes the description of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. | An assembly for lifting and storing an ice house or other item is herein disclosed. The assembly comprises a base and a plurality of horizontal brace members rigidly connected to one another. The assembly further comprises an electric winch mounted to the base and a plurality of rollers and pulleys. The rollers are rotatably attached to the base and the pulleys are connected to the horizontal brace members. The assembly includes at least one cable that is routed from the electric winch, past the roller and over the pulley. The cable is attached to the ice house. The ice house is lifted and suspended from a ceiling or an assembly of overhead beams via the electric winch. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to education systems and more particularly to a rule based tutorial system that utilizes business simulations of a retail environment to teach new store management skills.
BACKGROUND OF THE INVENTION
[0002] When building a knowledge based system or expert system, at least two disciplines are necessary to properly construct the rules that drive the knowledge base, the discipline of the knowledge engineer and the knowledge of the expert. The domain expert has knowledge of the domain or field of use of the expert system. For example, the domain expert of an expert for instructing students in an automotive manufacturing facility might be a process control engineer while the domain expert for a medical instruction system might be a doctor or a nurse. The knowledge engineer is a person that understands the expert system and utilizes the expert's knowledge to create an application for the system. In many instances, the knowledge engineer and domain expert are separate people who have to collaborate to construct the expert system.
[0003] Typically, this collaboration takes the form of the knowledge engineer asking questions of the domain expert and incorporating the answers to these questions into the design of the system. This approach is labor intensive, slow and error prone. The coordination of the two separate disciplines may lead to problems. Although the knowledge engineer can transcribe input from the expert utilizing videotape, audio tape, text and other sources, efforts from people of both disciplines have to be expended. Further, if the knowledge engineer does not ask the right questions or asks the questions in an incorrect way, the information utilized to design the knowledge base could be incorrect. Feedback to the knowledge engineer from the expert system is often not available in prior art system until the construction is completed. With conventional system, there is a time consuming feedback loop that ties together various processes from knowledge acquisition to validation.
[0004] Educational systems utilizing an expert system component often suffer from a lack of motivational aspects that result in a user becoming bored or ceasing to complete a training program. Current training programs utilize static, hard-coded feedback with some linear video and graphics used to add visual appeal and illustrate concepts. These systems typically support one “correct” answer and navigation through the system is only supported through a single defined path which results in a two-dimensional generic interaction, with no business model support and a single feedback to the learner of correct or incorrect based on the selected response. Current tutorial systems do not architect real business simulations into the rules to provide a creative learning environment to a user.
SUMMARY OF THE INVENTION
[0005] According to a broad aspect of a preferred embodiment of the invention, a goal based learning system utilizes a rule based expert training system to provide a cognitive educational experience. The system provides the user with a simulated environment that presents a business opportunity to understand and solve optimally. Mistakes are noted and remedial educational material presented dynamically to build the necessary skills that a user requires for success in the business endeavor. The system utilizes an artificial intelligence engine driving individualized and dynamic feedback with synchronized video and graphics used to simulate real-world environment and interactions. Multiple “corrects” answers are integrated into the learning system to allow individualized learning experiences in which navigation through the system is at a pace controlled by the learner. A robust business model provides support for realistic activities and allows a user to experience real world consequences for their actions and decisions and entails realtime decision-making and synthesis of the educational material. A dynamic feedback system is utilized that narrowly tailors feedback and focuses it based on the performance and characteristics of the student to assist the student in reaching a predefined goal. A store management tutorial system is enabled for providing active coaching on aspects of inventory management, stocking, advertising, return on revenue, markdown, assortment strategy and other aspects of retail management. Techniques for process sensitive help are also integrated into the system to provide contextual examples to guide a user in performing a task.
DESCRIPTION OF THE DRAWINGS
[0006] The foregoing and other objects, aspects and advantages are better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
[0007] [0007]FIG. 1 is a block diagram of a representative hardware environment in accordance with a preferred embodiment;
[0008] [0008]FIG. 2 is a block diagram of a system architecture in accordance with a preferred embodiment;
[0009] [0009]FIG. 3 depicts the timeline and relative resource requirements for each phase of development for a typical application development in accordance with a preferred embodiment;
[0010] [0010]FIG. 4 illustrates a small segment of a domain model for claims handlers in the auto insurance industry in accordance with a preferred embodiment;
[0011] [0011]FIG. 5 illustrates an insurance underwriting profile in accordance with a preferred embodiment;
[0012] [0012]FIG. 6 illustrates a transformation component in accordance with a preferred embodiment;
[0013] [0013]FIG. 7 illustrates the use of a toolbar to navigate and access application level features in accordance with a preferred embodiment;
[0014] [0014]FIG. 8 is a GBS display in accordance with a preferred embodiment;
[0015] [0015]FIG. 9 is a feedback display in accordance with a preferred embodiment;
[0016] [0016]FIG. 10 illustrates a journal entry simulation in accordance with a preferred embodiment;
[0017] [0017]FIG. 11 illustrates a simulated Bell Phone Bill journal entry in accordance with a preferred embodiment;
[0018] [0018]FIG. 12 illustrates a feedback display in accordance with a preferred embodiment;
[0019] [0019]FIG. 13 illustrates the steps of the first scenario in accordance with a preferred embodiment;
[0020] [0020]FIGS. 14 and 15 illustrate the steps associated with a build scenario in accordance with a preferred embodiment;
[0021] [0021]FIG. 16 illustrates a test scenario in accordance with a preferred embodiment. The test students work through the journalization activity;
[0022] [0022]FIG. 17 illustrates how the tool suite supports student administration in accordance with a preferred embodiment;
[0023] [0023]FIG. 18 illustrates a suite to support a student interaction in accordance with a preferred embodiment;
[0024] [0024]FIG. 19 illustrates the remediation process in accordance with a preferred embodiment;
[0025] [0025]FIG. 20 illustrates the objects for the journalization task in accordance with a preferred embodiment;
[0026] [0026]FIG. 21 illustrates the mapping of a source item to a target item in accordance with a preferred embodiment;
[0027] [0027]FIG. 22 illustrates an analysis of rules in accordance with a preferred embodiment;
[0028] [0028]FIG. 23 illustrates a feedback selection in accordance with a preferred embodiment;
[0029] [0029]FIG. 24 is a flowchart of the feedback logic in accordance with a preferred embodiment;
[0030] [0030]FIG. 25 is a block diagram setting forth the architecture of a simulation model in accordance with a preferred embodiment;
[0031] [0031]FIG. 26 illustrates the steps for configuring a simulation in accordance with a preferred embodiment;
[0032] [0032]FIG. 27 is a block diagram presenting the detailed architecture of a system dynamics model in accordance with a preferred embodiment;
[0033] [0033]FIG. 28 is an overview diagram of the logic utilized for initial configuration in accordance with a preferred embodiment;
[0034] [0034]FIG. 29 is a display of video information in accordance with a preferred embodiment; and
[0035] [0035]FIG. 30 illustrates an ICA utility in accordance with a preferred embodiment.
DETAILED DESCRIPTION
[0036] A preferred embodiment of a system in accordance with the present invention is preferably practiced in the context of a personal computer such as an IBM compatible personal computer, Apple Macintosh computer or UNIX based workstation. A representative hardware environment is depicted in FIG. 1, which illustrates a typical hardware configuration of a workstation in accordance with a preferred embodiment having a central processing unit 110 , such as a microprocessor, and a number of other units interconnected via a system bus 112 . The workstation shown in FIG. 1 includes a Random Access Memory (RAM) 114 , Read Only Memory (ROM) 116 , an I/O adapter 118 for connecting peripheral devices such as disk storage units 120 to the bus 112 , a user interface adapter 122 for connecting a keyboard 124 , a mouse 126 , a speaker 128 , a microphone 132 , user interface devices such as a touch screen (not shown) to the bus 112 , communication adapter 134 for connecting the workstation to a communication network (e.g., a data processing network) and a display adapter 136 for connecting the bus 112 to a display device 138 . The workstation typically has resident thereon an operating system such as the Microsoft Windows NT or Windows/95 Operating System (OS), the IBM OS/2 operating system, the MAC OS, or UNIX operating system. Those skilled in the art will appreciate that the present invention may also be implemented on platforms and operating systems other than those mentioned.
[0037] A preferred embodiment is written using JAVA, C, and the C++ language and utilizes object oriented programming methodology. Object oriented programming (OOP) has become increasingly used to develop complex applications. As OOP moves toward the mainstream of software design and development, various software solutions require adaptation to make use of the benefits of OOP. A need exists for these principles of OOP to be applied to a messaging interface of an electronic messaging system such that a set of OOP classes and objects for the messaging interface can be provided. A simulation engine in accordance with a preferred embodiment is based on a Microsoft Visual Basic component developed to help design and test feedback in relation to a Microsoft Excel spreadsheet. These spreadsheet models are what simulate actual business functions and become a task that will be performed by a student The Simulation Engine accepts simulation inputs and calculates various outputs and notifies the system of the status of the simulation at a given time in order to obtain appropriate feedback.
Relationship of Components
[0038] The simulation model executes the business function that the student is learning and is therefore the center point of the application. An activity ‘layer’ allows the user to visually guide the simulation by passing inputs into the simulation engine and receiving an output from the simulation model. For example, if the student was working on an income statement activity, the net sales and cost of goods sold calculations are passed as inputs to the simulation model and the net income value is calculated and retrieved as an output. As calculations are passed to and retrieved from the simulation model, they are also passed to the Intelligent Coaching Agent (ICA). The ICA analyzes the Inputs and Outputs to the simulation model and generates feedback based on a set of rules. This feedback is received and displayed through the Visual Basic Architecture.
[0039] [0039]FIG. 2 is a block diagram of a system architecture in accordance with a preferred embodiment. The Presentation ‘layer’ 210 is separate from the activity ‘layer’ 220 and communication is facilitated through a set of messages 230 that control the display specific content topics. A preferred embodiment enables knowledge workers 200 & 201 to acquire complex skills rapidly, reliably and consistently across an organization to deliver rapid acquisition of complex skills. This result is achieved by placing individuals in a simulated business environment that “looks and feels” like real work, and challenging them to make decisions which support a business strategic objectives utilizing highly effective learning theory (e.g., goal based learning, learn by doing, failure based learning, etc.), and the latest in multimedia user interfaces, coupled with three powerful, integrated software components. The first of these components is a software Solution Construction Aid (SCA) 230 consisting of a mathematical modeling tool 234 which simulates business outcomes of an individual's collective actions over a period of time. The second component is a knowledge system 250 consisting of an HTML content layer which organizes and presents packaged knowledge much like an online text book with practice exercises, video war stories, and a glossary. The third component is a software tutor 270 comprising an artificial intelligence engine 240 which generates individualized coaching messages based on decisions made by learner.
[0040] Feedback is unique for each individual completing the course and supports client cultural messages 242 “designed into” the course. A business simulation methodology that includes support for content acquisition, story line design, interaction design, feedback and coaching delivery, and content delivery is architected into the system in accordance with a preferred embodiment. A large number of “pre-designed” learning interactions such as drag and drop association of information 238 , situation assessment/action planning, interviewing (one-on-one, one-to-many), presenting (to a group of experts/executives), metering of performance (handle now, handle later), “time jumping” for impact of decisions, competitive landscape shift (while “time jumping”, competitors merge, customers are acquired, etc.) and video interviewing with automated note taking are also included in accordance with a preferred embodiment.
[0041] Business simulation in accordance with a preferred embodiment delivers training curricula in an optimal manner. This is because such applications provide effective training that mirrors a student's actual work environment. The application of skills “on the job” facilitates increased retention and higher overall job performance. While the results of such training applications are impressive, business simulations are very complex to design and build correctly. These simulations are characterized by a very open-ended environment, where students can go through the application along any number of paths, depending on their learning style and prior experiences/knowledge.
[0042] A category of learning approaches called Learn by Doing, is commonly used as a solution to support the first phase (Learn) of the Workforce Performance Cycle. However, it can also be a solution to support the second phase (Perform) of the cycle to enable point of need learning during job performance. By adopting the approach presented, some of the benefits of a technology based approach for building business simulation solutions which create more repeatable, predictable projects resulting in more perceived and actual user value at a lower cost and in less time are highlighted.
[0043] Most corporate training programs today are misdirected because they have failed to focus properly on the purpose of their training. These programs have confused the memorization of facts with the ability to perform tasks; the knowing of “that” with the knowing of “how”. By adopting the methods of traditional schools, businesses are teaching a wide breadth of disconnected, decontextualized facts and figures, when they should be focused on improved performance. How do you teach performance, when lectures, books, and tests inherently are designed around facts and figures? Throw away the lectures, books, and tests. The best way to prepare for high performance is to perform; experience is the best teacher! Most business leaders agree that workers become more effective the more time they spend in their jobs. The best approach for training novice employees, therefore, would be letting them learn on the job, acquiring skills in their actual work environment. The idea of learning-by-doing is not revolutionary, yet it is resisted in business and academia. Why is this so, if higher competence is universally desired?
[0044] Learners are reluctant to adopt learning-by-doing because they are frightened of failure. People work hard to avoid making mistakes in front of others. Business leaders are hesitant to implement learning-by-doing because novice failure may have dramatic safety, legal and financial implications. Imagine a novice pilot learning-by-doing as he accelerates a large jet plane down a runway; likewise, consider a new financial analyst learning-by-doing as he structures a multi-million dollar financial loan. Few employers are willing to endure such failures to have a more competent workforce.
[0045] The key to such a support system is that it is seamlessly integrated into the business system that the knowledge worker uses to execute their job tasks. Workers don't need to go “off-line” or seek out cryptic information buried within paper manuals and binders for guidance or to find the answer to queries. All the support components are made available through the same applications the worker's use, at the point in which they need them, tailored to the individual to show “how”, not just “what”. Learning would be occurring all the time, with little distinction between performing and improving performance. Establishing that training should focus on performance (how), rather than facts (what), and extending the model of learning to include assistance while performing, rather than only before performance, still leaves us dangerously exposed in preparing to compete in the new, chaotic economy. As was mentioned in the opening of this paper, the pace of change in business today is whiplash fast. Not only are new methods of doing business evolving every 18-24 months, new competitors emerge, dominate, and fade in time periods businesses used to take to perform demographic studies. Now more than ever, those who do not reinvent themselves on a regular basis will be fossilized by the pace of change. A typical BusSim engagement takes between one and two years to complete and requires a variety of both functional and technical skills. FIG. 3 depicts the timeline and relative resource requirements for each phase of development for a typical application development in accordance with a preferred embodiment. The chart clearly depicts the relationship between the large number of technical resources required for both the build and test phases of development. This is because the traditional development process used to build BusSim solutions reflects more of a “one off” philosophy, where development is done from scratch in a monolithic fashion, with little or no reuse from one application to the next. This lack of reuse makes this approach prohibitively expensive, as well as lengthy, for future BusSim projects.
[0046] The solution to this problem is to put tools in the hands of instructional designers that allows them to create their BusSim designs and implement them without the need for programmers to write code. And to put application architectures that integrate with the tools in the hands of developers, providing them with the ability to quickly deliver solutions for a number of different platforms. The reuse, then, comes in using the tools and architectures from one engagement to another. Both functional and technical resources carry with them the knowledge of how to use the technology, which also has an associated benefit of establishing a best-practice development methodology for BusSim engagements.
Development Cycle Activities
[0047] In the Design Phase, instructional designers become oriented to the content area and begin to conceptualize an instructional approach. They familiarize themselves with the subject matter through reading materials and interviews with Subject Matter Experts (SMEs). They also identify learning objectives from key client contacts. Conceptual designs for student interactions and interface layouts also begin to emerge. After the conceptual designs have taken shape, Low-Fi user testing (a.k.a. Conference Room Piloting) is performed. Students interact with interface mock-ups while facilitators observe and record any issues. Finally, detailed designs are created that incorporate findings. These detailed designs are handed off to the development team for implementation. The design phase has traditionally been fraught with several problems. Unlike a traditional business system, BusSim solutions are not rooted in tangible business processes, so requirements are difficult to identify in a concrete way. This leaves instructional designers with a ‘blue sky’ design problem. With few business-driven constraints on the solution, shallow expertise in the content area, and limited technical skills, instructional designers have little help in beginning a design. Typically, only experienced designers have been able to conjure interface, analysis, and feedback designs that meet the learning objectives yet remain technically feasible to implement. To compound the problem, BusSim solutions are very open ended in nature. The designer must anticipate a huge combination of student behavior to design feedback that is helpful and realistic.
[0048] During the build phase, the application development team uses the detailed designs to code the application. Coding tasks include the interfaces and widgets that the student interacts with. The interfaces can be made up of buttons, grids, check boxes, or any other screen controls that allow the student to view and manipulate his deliverables. The developer must also code logic that analyzes the student's work and provides feedback interactions. These interactions may take the form of text and/or multimedia feedback from simulated team members, conversations with simulated team members, or direct manipulations of the student's work by simulated team members. In parallel with these coding efforts, graphics, videos, and audio are being created for use in the application. Managing the development of these assets have their own complications. Risks in the build phase include misinterpretation of the designs. If the developer does not accurately understand the designer's intentions, the application will not function as desired. Also, coding these applications requires very skilled developers because the logic that analyzes the student's work and composes feedback is very complex.
[0049] The Test Phase, as the name implies, is for testing the application. Testing is performed to verify the application in three ways: first that the application functions properly (functional testing), second that the students understand the interface and can navigate effectively (usability testing), and third that the learning objectives are met (cognition testing). Functional testing of the application can be carded out by the development team or by a dedicated test team. If the application fails to function properly, it is debugged, fixed, recompiled and retested until its operation is satisfactory. Usability and cognition testing can only be carried out by test students who are unfamiliar with the application. If usability is unsatisfactory, parts of the interface and or feedback logic may need to be redesigned, recoded, and retested. If the learning objectives are not met, large parts of the application may need to be removed and completely redeveloped from a different perspective. The test phase is typically where most of the difficulties in the BusSim development cycle are encountered. The process of discovering and fixing functional, usability, and cognition problems is a difficult process and not an exact science.
[0050] For functional testing, testers operate the application, either by following a test script or by acting spontaneously and documenting their actions as they go. When a problem or unexpected result is encountered, it too is documented. The application developer responsible for that part of the application then receives the documentation and attempts to duplicate the problem by repeating the tester's actions. When the problem is duplicated, the developer investigates further to find the cause and implement a fix. The developer once again repeats the testers actions to verify that the fix solved the problem. Finally, all other test scripts must be rerun to verify that the fix did not have unintended consequences elsewhere in the application. The Execution Phase refers to the steady state operation of the completed application in its production environment. For some clients, this involves phone support for students. Clients may also want the ability to track students' progress and control their progression through the course. Lastly, clients may want the ability to track issues so they may be considered for inclusion in course maintenance releases.
[0051] One of the key values of on-line courses is that they can be taken at a time, location, and pace that is convenient for the individual student. However, because students are not centrally located, support is not always readily available. For this reason it is often desirable to have phone support for students. Clients may also desire to track students' progress, or control their advancement through the course. Under this strategy, after a student completes a section of the course, he will transfer his progress data to a processing center either electronically or by physically mailing a disk. There it can be analyzed to verify that he completed all required work satisfactorily. One difficulty commonly associated with student tracking is isolating the student data for analysis. It can be unwieldy to transmit all the course data, so it is often imperative to isolate the minimum data required to perform the necessary analysis of the student's progress.
A Delivery Framework for Business Simulation
[0052] As discussed earlier, the traditional development process used to build BusSim solutions reflects more of a “one off” philosophy, where development is done from scratch in a monolithic fashion, with little or no reuse from one application to the next. A better approach would be to focus on reducing the total effort required for development through reuse, which, in turn would decrease cost and development time. The first step in considering reuse as an option is the identification of common aspects of the different BusSim applications that can be generalized to be useful in future applications. In examination of the elements that make up these applications, three common aspects emerge as integral parts of each: Interface, Analysis and Interpretation. Every BusSim application must have a mechanism for interaction with the student. The degree of complexity of each interface may vary, from the high interactivity of a high-fidelity real-time simulation task, to the less complex information delivery requirements of a business case background information task. Regardless of how sophisticated the User Interface (UI), it is a vital piece of making the underlying simulation and feedback logic useful to the end user.
[0053] Every BusSim application does analysis on the data that defines the current state of the simulation many times throughout the execution of the application. This analysis is done either to determine what is happening in the simulation, or to perform additional calculations on the data which are then fed back into the simulation. For example, the analysis may be the recognition of any actions the student has taken on artifacts within the simulated environment (notebooks, number values, interviews conducted, etc.), or it may be the calculation of an ROI based on numbers the student has supplied. Substantive, useful feedback is a critical piece of any BusSim application. It is the main mechanism to communicate if actions taken by the student are helping or hurting them meet their performance objectives. The interpretation piece of the set of proposed commonalties takes the results of any analysis performed and makes sense of it. It takes the non-biased view of the world that the Analysis portion delivers (i.e., “Demand is up 3%”) and places some evaluative context around it (i.e., “Demand is below the expected 7%; you're in trouble!”, or “Demand has exceeded projections of 1.5%; Great job!”).
[0054] There are several approaches to capturing commonalties for reuse. Two of the more common approaches are framework-based and component-based. To help illustrate the differences between the two approaches, we will draw an analogy between building an application and building a house. One can construct a house from scratch, using the raw materials, 2×4s, nails, paint, concrete, etc. One can also construct an application from scratch, using the raw materials of new designs and new code. The effort involved in both undertakings can be reduced through framework-based and/or component-based reuse. Within the paradigm of framework-based reuse, a generic framework or architecture is constructed that contains commonalties. In the house analogy, one could purchase a prefabricated house framework consisting of floors, outside walls, bearing walls and a roof. The house can be customized by adding partition walls, wall-paper, woodwork, carpeting etc. Similarly, prefabricated application frameworks are available that contain baseline application structure and functionality. Individual applications are completed by adding specific functionality and customizing the look-and-feel. An example of a commonly used application framework is Microsoft Foundation Classes. It is a framework for developing Windows applications using C++. MFC supplies the base functionality of a windowing application and the developer completes the application by adding functionality within the framework. Framework-based reuse is best suited for capturing template-like features, for example user interface management, procedural object behaviors, and any other features that may require specialization. Some benefits of using a framework include:
[0055] Extensive functionality can be incorporated into a framework. In the house analogy, if I know I am going to build a whole neighborhood of three bedroom ranches, I can build the plumbing, wiring, and partition walls right into the framework, reducing the incremental effort required for each house. If I know I am going to build a large number of very similar applications, they will have more commonalties that can be included in the framework rather than built individually.
[0056] Applications can override the framework-supplied functionality wherever appropriate. If a house framework came with pre-painted walls, the builder could just paint over them with preferred colors. Similarly, the object oriented principle of inheritance allows an application developer to override the behavior of the framework. In the paradigm of component-based reuse, key functionality is encapsulated in a component. The component can then be reused in multiple applications. In the house analogy, components correspond to appliances such as dishwashers, refrigerators, microwaves, etc. Similarly, many application components with pre-packaged functionality are available from a variety of vendors. An example of a popular component is a Data Grid. It is a component that can be integrated into an application to deliver the capability of viewing columnar data in a spreadsheet-like grid. Component-based reuse is best suited for capturing black-box-like features, for example text processing, data manipulation, or any other features that do not require specialization.
[0057] Several applications on the same computer can share a single component. This is not such a good fit with the analogy, but imagine if all the houses in a neighborhood could share the same dishwasher simultaneously. Each home would have to supply its own dishes, detergent, and water, but they could all wash dishes in parallel. In the application component world, this type of sharing is easily accomplished and results in reduced disk and memory requirements.
[0058] Components tend to be less platform and tool dependent. A microwave can be used in virtually any house, whether it's framework is steel or wood, and regardless of whether it was customized for building mansions or shacks. You can put a high-end microwave in a low-end house and vice-versa. You can even have multiple different microwaves in your house. Component technologies such as CORBA, COM, and Java Beans make this kind of flexibility commonplace in application development. Often, the best answer to achieving reuse is through a combination of framework-based and component-based techniques. A framework-based approach for building BusSim applications is appropriate for developing the user interface, handling user and system events, starting and stopping the applications, and other application-specific and delivery platform-specific functions. A component-based approach is appropriate for black-box functionality. That is, functionality that can be used as—is with no specialization required. In creating architectures to support BusSim application development, it is imperative that any assets remain as flexible and extensible as possible or reusability may be diminished. Therefore, we chose to implement the unique aspects of BusSim applications using a component approach rather than a framework approach. This decision is further supported by the following observations.
Delivery Framework for Business Simulation
[0059] Components are combined with an Application Framework and an Application Architecture to achieve maximum reuse and minimum custom development effort. The Application Architecture is added to provide communication support between the application interface and the components, and between the components. This solution has the following features: The components (identified by the icons) encapsulate key BusSim functionality. The Application Architecture provides the glue that allows application-to-component and component-to-component communication. The Application Framework provides structure and base functionality that can be customized for different interaction styles. Only the application interface must be custom developed. The next section discusses each of these components in further detail.
The Business Simulation Toolset
[0060] We have clearly defined why a combined component/framework approach is the best solution for delivering high-quality BusSim solutions at a lower cost. Given that there are a number of third party frameworks already on the market that provide delivery capability for a wide variety of platforms, the TEL project is focused on defining and developing a set of components that provide unique services for the development and delivery of BusSim solutions. These components along with a set of design and test workbenches are the tools used by instructional designers to support activities in the four phases of BusSim development. We call this suite of tools the Business Simulation Toolset. Following is a description of each of the components and workbenches of the toolset. A Component can be thought of as a black box that encapsulates the behavior and data necessary to support a related set of services. It exposes these services to the outside world through published interfaces. The published interface of a component allows you to understand what it does through the services it offers, but not how it does it. The complexity of its implementation is hidden from the user. The following are the key components of the BusSim Toolset. Domain Component—provides services for modeling the state of a simulation. Profiling Component—provides services for rule-based evaluating the state of a simulation. Transformation Component—provides services for manipulating the state of a simulation. Remediation Component—provides services for the rule-based delivering of feedback to the student The Domain Model component is the central component of the suite that facilitates communication of context data across the application and the other components. It is a modeling tool that can use industry-standard database such as Informix, Oracle, or Sybase to store its data. A domain model is a representation of the objects in a simulation. The objects are such pseudo tangible things as a lever the student can pull, a form or notepad the student fills out, a character the student interacts with in a simulated meeting, etc. They can also be abstract objects such as the ROI for a particular investment, the number of times the student asked a particular question, etc. These objects are called entities. Some example entities include: Vehicles, operators and incidents in an insurance domain; Journal entries, cash flow statements and balance sheets in a financial accounting domain and Consumers and purchases in a marketing domain.
[0061] An entity can also contain other entities. For example, a personal bank account entity might contain an entity that represents a savings account. Every entity has a set of properties where each property in some way describes the entity. The set of properties owned by an entity, in essence, define the entity. Some example properties include: An incident entity on an insurance application owns properties such as “Occurrence Date”, “Incident Type Code”, etc. A journal entry owns properties such as “Credit Account”, “Debit Account”, and “Amount”; and a revolving credit account entity on a mortgage application owns properties such as “Outstanding Balance”, “Available Limit”, etc. FIG. 4 illustrates a small segment of a domain model for claims handlers in the auto insurance industry in accordance with a preferred embodiment.
Profiling Component
[0062] In the simplest terms, the purpose of the Profiling Component is to analyze the current state of a domain and identify specific things that are true about that domain. This information is then passed to the Remediation Component which provides feedback to the student. The Profiling Component analyzes the domain by asking questions about the domain's state, akin to an investigator asking questions about a case. The questions that the Profiler asks are called profiles. For example, suppose there is a task about building a campfire and the student has just thrown a match on a pile of wood, but the fire didn't start. In order to give useful feedback to the student, a tutor would need to know things like: was the match lit?, was the wood wet?, was there kindling in the pile?, etc. These questions would be among the profiles that the Profiling Component would use to analyze the domain. The results of the analysis would then be passed off to the Remediation Component which would use this information to provide specific feedback to the student. Specifically, a profile is a set of criteria that is matched against the domain. The purpose of a profile is to check whether the criteria defined by the profile is met in the domain. Using a visual editing tool, instructional designers create profiles to identify those things that are important to know about the domain for a given task. During execution of a BusSim application at the point that feedback is requested either by the student or pro-actively by the application, the set of profiles associated with the current task are evaluated to determine which ones are true. Example profiles include: Good productions strategy but wrong Break-Even Formula; Good driving record and low claims history; and Correct Cash Flow Analysis but poor Return on Investment (ROI)
[0063] A profile is composed of two types of structures: characteristics and collective characteristics. A characteristic is a conditional (the if half of a rule) that identifies a subset of the domain that is important for determining what feedback to deliver to the student. Example characteristics include: Wrong debit account in transaction 1 ; Perfect cost classification; At Least 1 DUI in the last 3 years; More than $4000 in claims in the last 2 years; and More than two at-fault accidents in 5 years A characteristic's conditional uses one or more atomics as the operands to identify the subset of the domain that defines the characteristic. An atomic only makes reference to a single property of a single entity in the domain; thus the term atomic. Example atomics include: The number of DUI's >=1; ROI>10%; and Income between $75,000 and $110,000. A collective characteristic is a conditional that uses multiple characteristics and/or other collective characteristics as its operands. Collective characteristics allow instructional designers to build richer expressions (i.e., ask more complex questions). Example collective characteristics include: Bad Household driving record; Good Credit Rating; Marginal Credit Rating; Problems with Cash for Expense transactions; and Problems with Sources and uses of cash. Once created, designers are able to reuse these elements within multiple expressions, which significantly eases the burden of creating additional profiles. When building a profile from its elements, atomics can be used by multiple characteristics, characteristics can be used by multiple collective characteristics and profiles, and collective characteristics can be used by multiple collective characteristics and profiles. FIG. 5 illustrates an insurance underwriting profile in accordance with a preferred embodiment.
Example Profile for Insurance Underwriting
[0064] Transformation Component—Whereas the Profiling Component asks questions about the domain, the Transformation Component performs calculations on the domain and feeds the results back into the domain for further analysis by the Profiling Component. This facilitates the modeling of complex business systems that would otherwise be very difficult to implement as part of the application. Within the Analysis phase of the Interface/Analysis/Interpretation execution flow, the Transformation Component actually acts on the domain before the Profiling Component does its analysis. The Transformation Component acts as a shell that wraps one or more data modeling components for the purpose of integrating these components into a BusSim application. The Transformation Component facilitates the transfer of specific data from the domain to the data modeling component (inputs) for calculations to be performed on the data, as well as the transfer of the results of the calculations from the data modeling component back to the domain (outputs). FIG. 6 illustrates a transformation component in accordance with a preferred embodiment. The data modeling components could be third party modeling environments such as spreadsheet-based modeling (e.g., Excel, Formula 1 ) or discrete time-based simulation modeling (e.g., PowerSim, VenSim). The components could also be custom built in C++, VB, Access, or any tool that is ODBC compliant to provide unique modeling environments. Using the Transformation Component to wrap a third party spreadsheet component provides an easy way of integrating into an application spreadsheet-based data analysis, created by such tools as Excel. The Transformation Component provides a shell for the spreadsheet so that it can look into the domain, pull out values needed as inputs, performs its calculations, and post outputs back to the domain.
[0065] For example, if the financial statements of a company are stored in the domain, the domain would hold the baseline data like how much cash the company has, what its assets and liabilities are, etc. The Transformation Component would be able to look at the data and calculate additional values like cash flow ratios, ROI or NPV of investments, or any other calculations to quantitatively analyze the financial health of the company. Depending on their complexity, these calculations could be performed by pre-existing spreadsheets that a client has already spent considerable time developing.
[0066] Remediation Component—The Remediation Component is an expert system that facilitates integration of intelligent feedback into BusSim applications. It has the following features: Ability to compose high quality text feedback; Ability to compose multimedia feedback that includes video and/or audio; Ability to include reference material in feedback such as Authorware pages or Web Pages and Ability to actively manipulate the users deliverables to highlight or even fix users' errors. A proven remediation theory embedded in its feedback composition algorithm allows integration of digital assets into the Remediation of a training or IPS application. The Remediation model consists of three primary objects: Concepts; Coach Topics and Coach Items. Concepts are objects that represent real-world concepts that the user will be faced with in the interface. Concepts can be broken into sub-concepts, creating a hierarchical tree of concepts. This tree can be arbitrarily deep and wide to support rich concept modeling. Concepts can also own an arbitrary number of Coach Topics. Coach Topics are objects that represent a discussion topic that may be appropriate for a concept. Coach Topics can own an arbitrary number of Coach Items. Coach Items are items of feedback that may include text, audio, video, URL's, or updates to the Domain Model. Coach Items are owned by Coach Topics and are assembled by the Remediation Component algorithm.
[0067] Workbenches—The BusSim Toolset also includes a set of workbenches that are used by instructional designers to design and build BusSim applications. A workbench is a tool that facilitates visual editing or testing of the data that the BusSim Components use for determining an application's run-time behavior. The BusSim Toolset includes the following workbenches: Knowledge Workbench—The Knowledge Workbench is a tool for the creation of domain, analysis and feedback data that is used by the BusSim Components. It has the following features: Allows the designer to ‘paint’ knowledge in a drag-and-drop interface; Knowledge is represented visually for easy communication among designers; The interface is intelligent, allowing designers to only paint valid interactions; Designer's Task creations are stored in a central repository; The workbench supports check-in/check-out for exclusive editing of a task; Supports LAN-based or untethered editing; Automatically generates documentation of the designs; and it Generates the data files that drive the behavior of the components. Simulated Student Test Workbench—The Simulated Student Test Workbench is a tool for the creation of data that simulates student's actions for testing BusSim Component behaviors. It has the following features: The Test Bench generates a simulated application interface based on the Domain Model; The designer manipulates the objects in the Domain Model to simulate student activity; The designer can invoke the components to experience the interactions the student will experience in production; and The designer can fully test the interaction behavior prior to development of the application interface. Regression Test Workbench—The Regression Test Workbench is a tool for replaying and testing of student sessions to aid debugging. It has the following features: Each student submission can be individually replayed through the components; An arbitrary number of student submissions from the same session can be replayed in succession; Entire student sessions can be replayed in batch instantly; The interaction results of the student are juxtaposed with the results of the regression test for comparison.
Development Cycle Activities
[0068] The design phase of a BusSim application is streamlined by the use of the Knowledge Workbench. The Knowledge Workbench is a visual editor for configuring the objects of the component engines to control their runtime behavior. The components are based on proven algorithms that capture and implement best practices and provide a conceptual framework and methodology for instructional design. In conceptual design, the workbench allows the designer to paint a model of the hierarchy of Concepts that the student will need to master in the activity. This helps the designer organize the content in a logical way. The visual representation of the Concepts helps to communicate ideas to other designers for review. The consistent look and feel of the workbench also contributes to a streamlined Quality Assurance process. In addition, standard documentation can be automatically generated for the entire design. As the design phase progresses, the designer adds more detail to the design of the Concept hierarchy by painting in Coach Topics that the student may need feedback on. The designer can associate multiple feedback topics with each Concept. The designer also characterizes each topic as being Praise, Polish, Focus, Redirect or one of several other types of feedback that are consistent with a proven remediation methodology. The designer can then fill each topic with text, video war stories, Web page links, Authorware links, or any other media object that can be delivered to the student as part of the feedback topic.
[0069] The toolset greatly reduces effort during functionality testing. The key driver of the effort reduction is that the components can automatically track the actions of the tester without the need to add code support in the application. Whenever the tester takes an action in the interface, it is reported to the domain model. From there it can be tracked in a database. Testers no longer need to write down their actions for use in debugging; they are automatically written to disk. There is also a feature for attaching comments to a testers actions. When unexpected behavior is encountered, the tester can hit a control key sequence that pops up a dialog to record a description of the errant behavior. During the Execution Phase, the components are deployed to the student's platform. They provide simulated team member and feedback functionality with sub-second response time and error-free operation. If the client desires it, student tracking mechanisms can be deployed at runtime for evaluation and administration of students. This also enables the isolation of any defects that may have made it to production.
Scenarios for Using the Business Simulation Toolset
[0070] A good way to gain a better appreciation for how the BusSim Toolset can vastly improve the BusSim development effort is to walk through scenarios of how the tools would be used throughout the development lifecycle of a particular task in a BusSim application. For this purpose, we'll assume that the goal of the student in a specific task is to journalize invoice transactions, and that this task is within the broader context of learning the fundamentals of financial accounting. A cursory description of the task from the student's perspective will help set the context for the scenarios. Following the description are five scenarios which describe various activities in the development of this task. The figure below shows a screen shot of the task interface. FIG. 7 illustrates the use of a toolbar to navigate and access application level features in accordance with a preferred embodiment. A student uses a toolbar to navigate and also to access some of the application-level features of the application. The toolbar is the inverted L-shaped object across the top and left of the interface. The top section of the toolbar allows the user to navigate to tasks within the current activity. The left section of the toolbar allows the student to access to access other features of the application, including feedback. The student can have his deliverables analyzed and receive feedback by clicking on the Team button.
[0071] In this task, the student must journalize twenty-two invoices and other source documents to record the flow of budget dollars between internal accounts. (Note: “Journalizing” or “Journalization”, is the process of recording journal entries in a general ledger from invoices or other source documents during an accounting period. The process entails creating debit and balancing credit entries for each document. At the completion of this process, the general ledger records are used to create a trial balance and subsequent financial reports.) In accordance with a preferred embodiment, an Intelligent Coaching Agent Tool (ICAT) was developed to standardize and simplify the creation and delivery of feedback in a highly complex and open-ended environment. Feedback from a coach or tutor is instrumental in guiding the learner through an application. Moreover, by diagnosing trouble areas and recommending specific actions based on predicted student understanding of the domain student comprehension of key concepts is increased. By writing rules and feedback that correspond to a proven feedback strategy, consistent feedback is delivered throughout the application, regardless of the interaction type or of the specific designer/developer creating the feedback. The ICAT is packaged with a user-friendly workbench, so that it may be reused to increase productivity on projects requiring a similar rule-based data engine and repository.
[0072] Definition of ICAT In Accordance with a Preferred Embodiment
[0073] The Intelligent Coaching Agent Tool (ICAT) is a suite of tools—a database and a Dynamic Link Library (DLL) run-time engine—used by designers to create and execute just-in-time feedback of Goal Based training. Designers write feedback and rules in the development tools. Once the feedback is set, the run-time engine monitors user actions, fires rules and composes feedback which describes the business deliverable. The remediation model used within ICAT dynamically composes the most appropriate feedback to deliver to a student based on student's previous responses. The ICAT model is based on a theory of feedback which has been proven effective by pilot results and informal interviews. The model is embodied in the object model and algorithms of the ICAT. Because the model is built into the tools, all feedback created with the tool will conform to the model. ICAT plays two roles in student training. First, the ICAT is a teaching system, helping students to fully comprehend and apply information. Second, ICAT is a gatekeeper, ensuring that each student has mastered the material before moving on to additional information. ICAT is a self contained module, separate from the application. Separating the ICAT from the application allows other projects to use the ICAT and allows designers to test feedback before the application is complete. The ICAT Module is built on six processes which allow a student to interact effectively with the interface to compose and deliver the appropriate feedback for a student's mistakes. ICAT development methodology is a seven step methodology for creating feedback. The methodology contains specific steps, general guidelines and lessons learned from the field. Using the methodology increases the effectiveness of the feedback to meet the educational requirements of the course. The processes each contain a knowledge model and some contain algorithms. Each process has specific knowledge architected into its design to enhance remediation and teaching. There is a suite of testing tools for the ICAT. These tools allow designers and developers test all of their feedback and rules. In addition, the utilities let designers capture real time activities of students as they go through the course. The tools and run-time engine in accordance with a preferred embodiment include expert knowledge of remediation. These objects include logic that analyzes a student's work to identify problem areas and deliver focused feedback. The designers need only instantiate the objects to put the tools to work. Embodying expert knowledge in the tools and engine ensures that each section of a course has the same effective feedback structure in place. A file structure in accordance with a preferred embodiment provides a standard system environment for all applications in accordance with a preferred embodiment. A development directory holds a plurality of sub-directories. The content in the documentation directory is part of a separate installation from the architecture. This is due to the size of the documentation directory. It does not require any support files, thus it may be placed on a LAN or on individual computers. When the architecture is installed in accordance with a preferred embodiment, the development directory has an_Arch, _Tools, _Utilities, Documentation, QED, and XDefault development directory. Each folder has its own directory structure that is inter-linked with the other directories. This structure must be maintained to assure consistency and compatibility between projects to clarify project differences, and architecture updates.
[0074] The _Arch directory stores many of the most common parts of the system architecture. These files generally do not change and can be reused in any area of the project. If there is common visual basic code for applications that will continuously be used in other applications, the files will be housed in a folder in this directory. The sub-directories in the _Arch directory are broken into certain objects of the main project. Object in this case refers to parts of a project that are commonly referred to within the project. For example, modules and classes are defined here, and the directory is analogous to a library of functions, APIs, etc . . . . that do not change. For example the IcaObj directory stores code for the Intelligent Coaching Agent (ICA). The InBoxObj directory stores code for the InBox part of the project and so on. The file structure uses some primary object references as file directories. For example, the IcaObj directory is a component that contains primary objects for the ICA such as functional forms, modules and classes. The BrowserObj directory contains modules, classes and forms related to the browser functionality in the architecture. The HTMLGlossary directory contains code that is used for the HTML reference and glossary component of the architecture. The IcaObj directory contains ICA functional code to be used in an application. This code is instantiated and enhanced in accordance with a preferred embodiment. The InBoxObj directory contains code pertaining to the inbox functionality used within the architecture. Specifically, there are two major components in this architecture directory. There is a new .ocx control that was created to provide functionality for an inbox in the application. There is also code that provides support for a legacy inbox application. The PracticeObj directory contains code for the topics component of the architecture. The topics component can be implemented with the HTMLGlossary component as well. The QmediaObj directory contains the components that are media related. An example is the QVIDctrl.cls. The QVIDctrl is the code that creates the links between QVID files in an application and the system in accordance with a preferred embodiment. The SimObj directory contains the Simulation Engine, a component of the application that notifies the tutor of inputs and outputs using a spreadsheet to facilitate communication. The StaticObj directory holds any component that the application will use statically from the rest of the application. For example, the login form is kept in this folder and is used as a static object in accordance with a preferred embodiment. The SysDynObj directory contains the code that allows the Systems Dynamics Engine (Powersim) to pass values to the Simulation Engine and return the values to the tutor. The VBObj directory contains common Visual Basic objects used in applications. For example the NowWhat, Visual Basic Reference forms, and specific message box components are stored in this folder. The _Tools directory contains two main directories. They represent the two most used tools in accordance with a preferred embodiment. The two directories provide the code for the tools themselves. The reason for providing the code for these tools is to allow a developer to enhance certain parts of the tools to extend their ability. This is important for the current project development and also for the growth of the tools. The Icautils directory contains a data, database, default, graphics, icadoc, and testdata directory. The purpose of all of these directories is to provide a secondary working directory for a developer to keep their testing environment of enhanced Icautils applications separate from the project application. It is built as a testbed for the tool only. No application specific work should be done here. The purpose of each of these directories will be explained in more depth in the project directory section. The TestData folder is unique to the _Tools/ICAUtils directory. It contains test data for the regression bench among others components in ICAUtils.
[0075] The Utilities directory holds the available utilities that a Business Simulation project requires for optimal results. This is a repository for code and executable utilities that developers and designers may utilize and enhance in accordance with a preferred embodiment. Most of the utilities are small applications or tools that can be used in the production of simulations which comprise an executable and code to go with it for any enhancements or changes to the utility. If new utilities are created on a project or existing utilities are enhanced, it is important to notify the managers or developers in charge of keeping track of the Business Simulation assets. Any enhancements, changes or additions to the Business Simulation technology assets are important for future and existing projects.
[0076] In the ICAT model of feedback, there are four levels of severity of error and four corresponding levels of feedback. The tutor goes through the student's work, identifies the severity of the error and then provides the corresponding level of feedback.
Educational Categories of Feedback ERROR FEEDBACK Error Feedback Type Description Type Description None No errors Praise Confirmation that the student exist. The completed the task correctly. student's Example: Great. You have work is journalized all accounts perfect. correctly. I am happy to see you recognized we are paying for most of our bills “on account”. Syntactic There may Polish Tells the student the specific be spelling actions he did incorrectly, mistakes or and possibly correct other them for him. syntactic Example: errors. As a There are one or two errors in designer, your work. It looks like you you should misclassified the purchase of be confident the fax as a cash purchase when that the it is really a purchase student will on account. have mastered the material at this point. Local A Focus Focus the student on this area paragraph of of his work. Point out that he a paper is does not understand at least one missing or major concept. the student Example: has made a Looking over your work, I see number of that you do not understand the mistakes all concept of “on account”. Why in one area. don't you review that concept The student and review your work for errors. clearly does not understand this area. Global The student Redirect Restate the goal of the activity has written and tell the student to review on the wrong main concepts and retry the subject or activity. “There are lots of there are mistakes throughout your work. mistakes all You need to think about what over the type of transaction each source student's document represents before work journalizing it.”
[0077] Returning to the analogy of helping someone write a paper, if the student writes on the wrong subject, this as a global error requiring redirect feedback. If the student returns with the paper rewritten, but with many errors in one area of the paper, focus feedback is needed. With all of those errors fixed and only spelling mistakes—syntactic mistakes—polish feedback is needed. When all syntactic mistakes were corrected, the tutor would return praise and restate why the student had written the correct paper. Focusing on the educational components of completing a task is not enough. As any teacher knows, student will often try and cheat their way through a task. Students may do no work and hope the teacher does not notice or the student may only do minor changes in hope of a hint or part of the answer. To accommodate these administrative functions, there are three additional administrative categories of feedback. The administrative and the educational categories of feedback account for every piece of feedback a designer can write and a student can receive. To provide a better understanding of how the feedback works together, an example is provided below.
[0078] [0078]FIG. 8 is a GBS display in accordance with a preferred embodiment. The upper right area of the screen shows the account list. There are four types of accounts: Assets, Liabilities & Equity, Revenues, and Expenses. The user clicks on one of the tabs to show the accounts of the corresponding type. The student journalizes a transaction by dragging an account from the account list onto the journal entry Debits or Credits. The student then enters the dollar amounts to debit or credit each account in the entry. In the interface, as in real life, the student can have multi-legged journal entries (i.e., debiting or crediting multiple accounts).A Toolbar 1200 and the first transaction of this Task 1210 appear prominently on the display. The student can move forward and back through the stack of transactions. For each transaction, the student must identify which accounts to debit and which to credit. When the student is done, he clicks the Team button. FIG. 9 is a feedback display in accordance with a preferred embodiment. The student may attempt to outsmart the system by submitting without doing anything. The ICAT system identifies that the student has not done a substantial amount of work and returns the administrative feedback depicted in FIG. 9. The feedback points out that nothing has been done, but it also states that if the student does some work, the tutor will focus on the first few journal entries. FIG. 10 illustrates a journal entry simulation in accordance with a preferred embodiment. FIG. 11 illustrates a simulated Bell Phone Bill journal entry in accordance with a preferred embodiment. The journal entry is accomplished by debiting Utilities Expenses and Crediting Cash for $700 each. FIG. 12 illustrates a feedback display in accordance with a preferred embodiment. After attempting to journalize the first three transactions, the student submits his work and receives the feedback depicted in FIG. 12. The feedback starts by focusing the student on the area of work being evaluated. The ICAT states that it is only looking at the first three journal entries. The feedback states that the first two entries are completely wrong, but the third is close. If the student had made large mistakes on each of the first three transactions, then the ICAT may have given redirect feedback, thinking a global error occurred. The third bullet point also highlights how specific the feedback can become, identifying near misses.
[0079] Design Scenario—This Scenario illustrates how the tools are used to support conceptual and detailed design of a BusSim application. FIG. 13 illustrates the steps of the first scenario in accordance with a preferred embodiment. The designer has gathered requirements and determined that to support the client's learning objectives, a task is required that teaches journalization skills. The designer begins the design first by learning about journalization herself, and then by using the Knowledge Workbench to sketch a hierarchy of the concepts she want the student to learn. At the most general level, she creates a root concept of ‘Journalization’. She refines this by defining sub-concepts of ‘Cash related transactions’, ‘Expense related Transactions’, and ‘Expense on account transactions’. These are each further refined to whatever level of depth is required to support the quality of the learning and the fidelity of the simulation. The designer then designs the journalization interface. Since a great way to learn is by doing, she decides that the student should be asked to Journalize a set of transactions. She comes up with a set of twenty-two documents that typify those a finance professional might see on the job. They include the gamut of Asset, Expense, Liability and Equity, and Revenue transactions. Also included are some documents that are not supposed to be entered in the journal. These ‘Distracters’ are included because sometimes errant documents occur in real life. The designer then uses the Domain Model features in the Knowledge Workbench to paint a Journal. An entity is created in the Domain Model to represent each transaction and each source document. Based on the twenty-two documents that the designer chose, she can anticipate errors that the student might make. For these errors, she creates topics of feedback and populates them with text. She also creates topics of feedback to tell the student when they have succeeded. Feedback Topics are created to handle a variety of situations that the student may cause.
[0080] The next step is to create profiles that the will trigger the topics in the concept tree (this task is not computational in nature, so the Transformation Component does not need to be configured) . A profile resolves to true when its conditions are met by the student's work. Each profile that resolves to true triggers a topic. To do some preliminary testing on the design, the designer invokes the Student Simulator Test Workbench. The designer can manipulate the Domain Model as if she were the student working in the interface. She drags accounts around to different transactions, indicating how she would like them journalized. She also enters the dollar amounts that she would like to debit or credit each account. She submits her actions to the component engines to see the feedback the student would get if he had performed the activity in the same way. All of this occurs in the test bench without an application interface. The last step in this phase is low-fi user testing. A test student interacts with a PowerPoint slide or bitmap of the proposed application interface for the Journalization Task. A facilitator mimics his actions in the test bench and tells him what the feedback would be. This simplifies low-fi user testing and helps the designer to identify usability issues earlier in the design when they are much cheaper to resolve.
[0081] [0081]FIGS. 14 and 15 illustrate the steps associated with a build scenario in accordance with a preferred embodiment. The instructional designer completes the initial interaction and interface designs as seen in the previous Scenario. After low-fi user testing, the Build Phase begins. Graphic artists use the designs to create the bitmaps that will make up the interface. These include bitmaps for the buttons, tabs, and transactions, as well as all the other screen widgets. The developer builds the interface using the bitmaps and adds the functionality that notifies the Domain Model of student actions. Standard event-driven programming techniques are used to create code that will react to events in the interface during application execution and pass the appropriate information to the Domain Model. The developer does not need to have any deep knowledge about the content because she does not have to build any logic to support analysis of the student actions or feedback. The developer also codes the logic to rebuild the interface based on changes to the domain model. A few passes through these steps will typically be required to get the application communicating correctly with the components. The debug utilities and Regression Test Workbench streamline the process. After the application interface and component communication are functioning as designed, the task is migrated to Usability testing.
[0082] The Test Scenario demonstrates the cycle that the team goes through to test the application. It specifically addresses usability testing, but it is easy to see how the tools also benefit functional and cognition testing. Again, we will use the Journalization Task as an example. FIG. 16 illustrates a test scenario in accordance with a preferred embodiment. The test students work through the journalization activity. One of the students has made it over half way through the task and has just attempted to journalize the sixteenth transaction. The student submits to the Financial Coach, but the feedback comes back blank. The student notifies the facilitator who right-clicks on the Financial Coach's face in the feedback window. A dialog pops up that shows this is the twenty-seventh submission and shows some other details about the submission. The facilitator (or even the student in recent efforts) enters a text description of the problem, and fills out some other fields to indicate the nature and severity of the problem. All the student's work and the feedback they got for the twenty-seven submissions is posted to the User Acceptance Test (UAT) archive database. The instructional designer can review all the student histories in the UAT database and retrieve the session where the student in question attempted the Journalization Task. The designer then recreates the problem by replaying the student's twenty-seven submissions through the component engines using the Regression Test Workbench. The designer can then browse through each submission that the student made and view the work that the student did on the submission, the feedback the student got, and the facilitator comments, if any. Now the designer can use the debugging tools to determine the source of the problem. In a few minutes, she is able to determine that additional profiles and topics are needed to address the specific combinations of mistakes the student made. She uses the Knowledge Workbench to design the new profiles and topics. She also adds a placeholder and a script for a video war story that supports the learning under these circumstances. The designer saves the new design of the task and reruns the Regression Test Workbench on the student's session with the new task design. After she is satisfied that the new profiles, topics, and war stories are giving the desired coverage, she ships the new task design file to user testing and it's rolled out to all of the users.
[0083] Execution Scenario: Student Administration—FIG. 17 illustrates how the tool suite supports student administration in accordance with a preferred embodiment. When a student first enters a course she performs a pre-test of his financial skills and fills out an information sheet about his job role, level, etc. This information is reported to the Domain Model. The Profiling Component analyzes the pre-test, information sheet, and any other data to determine the specific learning needs of this student. A curriculum is dynamically configured from the Task Library for this student. The application configures its main navigational interface (if the app has one) to indicate that this student needs to learn Journalization, among other things. As the student progresses through the course, his performance indicates that his proficiency is growing more rapidly in some areas than in others. Based on this finding, his curriculum is altered to give him additional Tasks that will help him master the content he is having trouble with. Also, Tasks may be removed where he has demonstrated proficiency. While the student is performing the work in the Tasks, every action he takes, the feedback he gets, and any other indicators of performance are tracked in the Student Tracking Database. Periodically, part or all of the tracked data are transmitted to a central location. The data can be used to verify that the student completed all of the work, and it can be further analyzed to measure his degree of mastery of the content.
[0084] Execution Scenario: Student Interaction—FIG. 18 illustrates a suite to support a student interaction in accordance with a preferred embodiment. In this task the student is trying to journalize invoices. He sees a chart of accounts, an invoice, and the journal entry for each invoice. He journalizes a transaction by dragging and dropping an account from the chart of accounts onto the ‘Debits’ or the ‘Credits’ line of the journal entry and entering the dollar amount of the debit or credit. He does this for each transaction. As the student interacts with the interface, all actions are reported to and recorded in the Domain Model. The Domain Model has a meta-model describing a transaction, its data, and what information a journal entry contains. The actions of the student populates the entities in the domain model with the appropriate information. When the student is ready, he submits the work to a simulated team member for review. This submission triggers the Analysis-Interpretation cycle. The Transformation Component is invoked and performs additional calculations on the data in the Domain Model, perhaps determining that Debits and Credits are unbalanced for a given journal entry. The Profiling Component can then perform rule-based pattern matching on the Domain Model, examining both the student actions and results of any Transformation Component analysis. Some of the profiles fire as they identify the mistakes and correct answers the student has given. Any profiles that fire activate topics in the Remediation Component. After the Profiling Component completes, the Remediation Component is invoked. The remediation algorithm searches the active topics in the tree of concepts to determine the best set of topics to deliver. This set may contain text, video, audio, URLs, even actions that manipulate the Domain Model. It is then assembled into prose-like paragraphs of text and media and presented to the student. The text feedback helps the student localize his journalization errors and understand why they are wrong and what is needed to correct the mistakes. The student is presented with the opportunity to view a video war story about the tax and legal consequences that arise from incorrect journalization. He is also presented with links to the reference materials that describe the fundamentals of journalization. The Analysis-Interpretation cycle ends when any coach items that result in updates to the Domain Model have been posted and the interface is redrawn to represent the new domain data. In this case, the designer chose to highlight with a red check the transactions that the student journalized incorrectly.
The Functional Definition of the ICAT
[0085] This section describes the feedback processes in accordance with a preferred embodiment. For each process, there is a definition of the process and a high-level description of the knowledge model. This definition is intended to give the reader a baseline understanding of some of the key components/objects in the model, so that he can proceed with the remaining sections of this paper. Refer to the Detailed Components of the ICAT for a more detailed description of each of the components within each knowledge model. To gain a general understanding of the ICAT, read only the general descriptions. To understand the ICAT deeply, read this section and the detailed component section regarding knowledge models and algorithms. These processes and algorithms embody the feedback model in the ICAT. There are six main processes in the ICAT, described below and in more detail on the following pages.
[0086] [0086]FIG. 19 illustrates the remediation process in accordance with a preferred embodiment. Remediation starts as students interact with the application's interface (process # 1 ). As the student tries to complete the business deliverable, the application sends messages to the ICAT about each action taken (process # 2 ). When the student is done and submits work for review, the ICAT compares how the student completed the activity with how the designer stated the activity should be completed (this is called domain knowledge). From this comparison, the ICAT get a count of how many items are right, wrong or irrelevant (process # 3 ). With the count complete, the ICAT tries to fire all rules (process # 4 ). Any rules which fire activate a coach (process # 5 ). The feedback algorithm selects pieces of feedback to show and composes them into coherent paragraphs of text (process # 6 ). Finally, as part of creating feedback text paragraphs, the ICAT replaces all variables in the feedback with specifics from the student's work. This gives the feedback even more specificity, so that it is truly customized to each student's actions.
[0087] Knowledge Model—Interface Objects In any GBS Task, the student must manipulate controls on the application interface to complete the required deliverables. FIG. 20 illustrates the objects for the journalization task in accordance with a preferred embodiment. The following abstract objects are used to model all the various types of interface interactions. A SourceItem is an object the student uses to complete a task. In the journalization example, the student makes a debit and credit for each transaction. The student has a finite set of accounts with which to respond for each transaction. Each account that appears in the interface has a corresponding SourceItem object. In other words, the items the student can manipulate to complete the task (account names) are called SourceItem. A Source is an object that groups a set of SourceItem objects together. Source objects have a One-To-Many relationship with SourceItem objects. In the journalization example, there are four types of accounts: Assets, Liabilities and Equity, Revenues, and Expenses. Each Account is of one and only one of these types and thus appears only under the appropriate tab. For each of the Account type tabs, there is a corresponding Source Object. A Target is a fixed place where students place SourceItems to complete a task. In the journalization example, the student places accounts on two possible targets: debits and credits. The top two lines of the journal entry control are Debit targets and the bottom two lines are Credit targets. These two targets are specific to the twelfth transaction. A TargetPage is an object that groups a set of Target objects together. TargetPage objects have a One-To-Many relationship with Target objects (just like the Source to SourceItem relationship). In the journalization example, there is one journal entry for each of the twenty-two transactions. For each journal entry there is a corresponding TargetPage object that contains the Debits Target and Credits Target for that journal entry.
[0088] As the student manipulates the application interface, each action is reported to the ICAT. In order to tell the ICAT what actions were taken, the application calls to a database and asks for a specific interface control's ID. When the application has the ID of the target control and the SourceItem control, the application notifies the ICAT about the Target to SourceItem mapping. In other words, every time a student manipulates a source item and associates it with a target (e.g., dragging an account name to a debit line in the journal), the user action is recorded as a mapping of the source item to the target. This mapping is called a UserSourceItemTarget. FIG. 21 illustrates the mapping of a source item to a target item in accordance with a preferred embodiment. When the student is ready, he submits his work to one of the simulated team members by clicking on the team member's icon. When the ICAT receives the student's work, it calculates how much of the work is correct by concept. Concepts in our journalization activity will include Debits, Credits, Asset Accounts, etc. For each of these concepts, the ICAT will review all student actions and determine how many of the student actions were correct. In order for the ICAT to understand which targets on the interface are associated with each concept, the targets are bundled into target groups and prioritized in a hierarchy. Once all possible coach topics are activated, a feedback selection analyzes the active pieces of remediation within the concept hierarchy and selects the most appropriate for delivery. The selected pieces of feedback are then assembled into a cohesive paragraph of feedback and delivered to the student. FIG. 23 illustrates a feedback selection in accordance with a preferred embodiment. After the ICAT has activated CoachTopics via Rule firings, the Feedback Selection Algorithm is used to determine the most appropriate set of CoachItems (specific pieces of feedback text associated with a CoachTopic) to deliver. The Algorithm accomplishes this by analyzing the concept hierarchy (TargetGroup tree), the active CoachTopics, and the usage history of the CoachItems. FIG. 24 is a flowchart of the feedback logic in accordance with a preferred embodiment. There are five main areas to the feedback logic which execute sequentially as listed below. First, the algorithm looks through the target groups and looks for the top-most target group with an active coach topic in it. Second, the algorithm then looks to see if that top-most coach item is praise feedback. If it is praise feedback, then the student has correctly completed the business deliverable and the ICAT will stop and return that coach item. Third, if the feedback is not Praise, then the ICAT will look to see if it is redirect, polish, mastermind or incomplete-stop. If it is any of these, then the algorithm will stop and return that feedback to the user. Fourth, if the feedback is focus, then the algorithm looks to the children target groups and groups any active feedback in these target groups with the focus group header. Fifth, once the feedback has been gathered, then the substitution language is run which replaces substitution variables with the proper names. Once the ICAT has chosen the pieces of feedback to return, the feedback pieces are assembled into a paragraph. With the paragraph assembled, the ICAT goes through and replaces all variables. There are specific variables for SourceItems and Targets. Variables give feedback specificity. The feedback can point out which wrong SourceItems were placed on which Targets. It also provides hints by providing one or two SourceItems which are mapped to the Target.
[0089] The Steps Involved in Creating Feedback in Accordance With A Preferred Embodiment
[0090] The goal of feedback is to help a student complete a business deliverable. The tutor needs to identify which concepts the student understands and which he does not. The tutor needs to tell the student about his problems and help him understand the concepts. There are seven major steps involved in developing feedback for an application. First, creating a strategy—The designer defines what the student should know. Second, limit errors through interface—The designer determines if the interface will identify some low level mistakes. Third, creating a target group hierarchy—The designer represents that knowledge in the tutor. Fourth, sequencing the target group hierarchy—The designer tells the tutor which concepts should be diagnosed first. Fifth, writing feedback—The designer writes feedback which tells the student how he did and what to do next. Sixth, writing Levels of Feedback—The designer writes different levels of feedback in case the student makes the same mistake more than once. Seventh, writing rules—The designer defines patterns which fire the feedback.
[0091] A feedback strategy is a loose set of questions which guide the designer as he creates rules and feedback. The strategy describes what the student should learn, how he will try and create the business deliverable and how an expert completes the deliverable. The goal of the application should be for the student to transition from the novice model to the expert model. What should the student know after using the application? The first task a designer needs to complete is to define exactly what knowledge a student must learn by the end of the interaction. Should the student know specific pieces of knowledge, such as formulas? Or, should the student understand high level strategies and detailed business processes? This knowledge is the foundation of the feedback strategy. The tutor needs to identify if the student has used the knowledge correctly, or if there were mistakes. An example is the journal task. For this activity, students need to know the purpose of the journalizing activity, the specific accounts to debit/credit, and how much to debit/credit. A student's debit/credit is not correct or incorrect in isolation, but correct and incorrect in connection with the dollars debited/credited. Because there are two different types of knowledge—accounts to debit/credit and amounts to debit/credit—the feedback needs to identify and provide appropriate feedback for both types of mistakes.
[0092] How will a novice try and complete the task? Designers should start by defining how they believe a novice will try and complete the task. Which areas are hard and which are easy for the student. This novice view is the mental model a student will bring to the task and the feedback should help the student move to an expert view. Designers should pay special attention to characteristic mistakes they believe the student will make. Designers will want to create specific feedback for these mistakes. An example is mixing up expense accounts in the journal activity. Because students may mix up some of these accounts, the designer may need to write special feedback to help clear up any confusion.
[0093] How does an expert complete the task? This is the expert model of completing the task. The feedback should help students transition to this understanding of the domain. When creating feedback, a designer should incorporate key features of the expert model into the praise feedback he writes. When a student completes portion of the task, positive reinforcement should be provided which confirms to the student that he is doing the task correctly and can use the same process to complete the other tasks. These four questions are not an outline for creating feedback, but they define what the feedback and the whole application needs to accomplish. The designer should make sure that the feedback evaluates all of the knowledge a student should learn. In addition, the feedback should be able to remediate any characteristic mistakes the designer feels the student will make. Finally, the designer should group feedback so that it returns feedback as if it were an expert. With these components identified, a designer is ready to start creating target group hierarchies. Because there are positive and negative repercussions, designers need to select the when to remediate through the interface carefully. The criteria for making the decision is if the mistake is a low level data entry mistake or a high level intellectual mistake. If the mistake is a low level mistake, such as miss-typing data, it may be appropriate to remediate via the interface. If the designer decides to have the interface point out the mistakes, it should look as if the system generated the message. System generated messages are mechanical checks, requiring no complex reasoning. In contrast, complex reasoning, such as why a student chose a certain type of account to credit or debit should be remediated through the ICAT.
[0094] System messages—It is very important that the student know what type of remediation he is going to get from each source of information. Interface based remediation should look and feel like system messages. They should use a different interface from the ICAT remediation and should have a different feel. In the journalization task described throughout this paper, there is a system message which states “Credits do not equal debits.” This message is delivered through a different interface and the blunt short sentence is unlike all other remediation. The motivation for this is that low level data entry mistakes do not show misunderstanding but instead sloppy work. Sloppy-work mistakes do not require a great deal of reasoning about why they occurred instead, they simply need to be identified. High-level reasoning mistakes, however, do require a great deal of reasoning about why they occurred, and the ICAT provides tools, such as target groups, to help with complex reasoning. Target group hierarchies allow designers to group mistakes and concepts together and ensure that they are remediated at the most appropriate time (i.e., Hard concepts will be remediated before easy concepts). Timing and other types of human-like remediation require the ICAT; other low-level mistakes which do not require much reasoning include: Incomplete—If the task requires a number of inputs, the interface can check that they have all been entered before allowing the student to proceed. By catching empty fields early in the process, the student may be saved the frustration of having to look through each entry to try and find the empty one. Empty—A simple check for the system is to look and see if anything has been selected or entered. If nothing has been selected, it may be appropriate for the system to generate a message stating “You must complete X before proceeding”. Numbers not matching—Another quick check is matching numbers. As in the journalization activity, is often useful to put a quick interface check in place to make sure numbers which must match do. Small data entry mistakes are often better remediated at the interface level than at the tutor or coach level (when they are not critical to the learning objectives of the course). There are two main issues which must be remembered when using the interface to remediate errors. First, make sure the interface is remediating low level data entry errors. Second, make sure the feedback looks and feels different from the ICAT feedback. The interface feedback should look and feel like it is generated from the system while the ICAT feedback must look as if it were generated from an intelligent coach who is watching over the student as he works.
[0095] Creating the Target Group Hierarchy—Target groups are sets of targets which are evaluated as one. Returning to the severity principle of the feedback theory, it is clear that the tutor needs to identify how much of the activity the student does not understand. Is it a global problem and the student does not understand anything about the activity? Or, is it a local problem and the student simply is confused over one concept? Using the feedback algorithm described earlier, the tutor will return the highest target group in which there is feedback. This algorithm requires that the designer start with large target groups and make sub-groups which are children of the larger groups. The ICAT allows students to group targets in more than one category. Therefore a debit target for transaction thirteen can be in a target group for transaction thirteen entries as well as a target group about debits and a target group which includes all source documents. Target should be grouped with four key ideas in mind. Target groups are grouped according to: Concepts taught; Interface constraints; Avoidance of information overload and Positive reinforcement.
[0096] The most important issue when creating target groups is to create them along the concepts students need to know to achieve the goal. Grouping targets into groups which are analogous to the concepts a student needs to know, allows the tutor to review the concepts and see which concepts confuse the student. As a first step, a designer should identify in an unstructured manner all of the concepts in the domain. This first pass will be a large list which includes concepts at a variety of granularities, from small specific concepts to broad general concepts. These concepts are most likely directly related to the learning objectives of the course. With all of the concepts defined, designers need to identify all of the targets which are in each target group. Some targets will be in more than one target group. When a target is in more than one target group, it means that there is some type of relationship such as a child relationship or a part to whole relationship. The point is not to create a structured list of concepts but a comprehensive list. Structuring them into a hierarchy will be the second step of the process.
* Notes: Loads from Database or Document based on values * of m_StorageTypeTask and m_StorageTypeStudent * **************************************** */ extern “C” { long _export WINAPI TuResumeStudent(long StudentID, long TaskID, int fromSubmissionSeqID); // Resumes a Student's work for the Task at the specified Submission } extern “C” { long export WINAPI TuLoadArchivedSubmissions(long StudentID, long TaskID, int fromSubmissionSeqID, int toSubmissionSeqID); // Loads Archived Submissions For a Student's work in a Task } extern “C” { long _export WINAPI TuUseArchivedSubmissions(int n); // Replays n Archived submissions for debugging } extern “C” { long _export WINAPI TuSaveCurrentStudent( ); // Saves Current Student's work to DB } extern “C” { long export WINAPI KillEngine(long ITaskID); // Delete all Dynamic objects before shutdown * Function Return * Variables: TUT_ERR_OK * * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetTaskDocPathName(LPCSTR fnm); } /* **************************************** * Name: TuSetFeedbackFileName * Purpose: To set path and name of file to use for holding feedback * Input * Parameters: LPCSTR fnm * Path and name of file to use for holding feedback * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetFeedbackFileName(LPCSTR fnm); } /* **************************************** * Name: TuSetFeedbackPrevFileName * Purpose: To set path and name of file to use for holding previous feedback * Input * Parameters: LPCSTR fnm * Path and name of file to use for holding previous feedback * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetFeedbackPrevFileName(LPCSTR fnm); /* **************************************** * Name: TuSetLogFileName * Purpose: To set path and name of file to use for full logging * Input * Parameters: LPCSTR fnm * Path and name of file to use for full logging * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetLogFileName(LPCSTR fnm); } /* **************************************** * Name: TuSetLogLoadFileName * Purpose: To set path and name of file to use for load logging * Input * Parameters: LPCSTR fnm * Path and name of file to use for load logging * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetLogLoadFileName(LPCSTR fnm); } /* **************************************** * Name: TuSetLogStudentFileName * Purpose: To set path and name of file to use for student logging * Input * Parameters: LPCSTR fnm * Path and name of file to use for student logging * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetLogStudentFileName(LPCSTR fnm); } /* **************************************** * Name: TuSetLogSubmissionFileName * Purpose: To set path and name of file to use for submission logging * Input * Parameters: LPCSTR fnm * Path and name of file to use for submission logging * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK * * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetLogSubmissionFileName(LPCSTR fnm); } /* **************************************** * Name: TuSetLogErrFileName * Purpose: To set path and name of file to use for error logging * Input * Parameters: LPCSTR fnm * Path and name of file to use for error logging * Output * Parameters: none * * Function Return * Variables: TUT_ERR_OK *Notes: **************************************** */ extern “C” { long _export WINAPI TuSetLogErrFileName(LPCSTR fnm); } /* **************************************** *Name: TuSetTrace * Purpose: To turn Trace on and off * Input * Parameters: int TraceStatus * TUT_TRACE_ON: Turn Trace On * TUT_TRACE_OFF: Turn Trace Off * Output * Parameters: none * * Function Return * Variables: Previous Trace Status Value * TUT_TRACE_ON * TUT_TRACE_OFF * * TUT_ERR_INVALID_TRACE_STATUS * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetTrace(int TraceStatus); } /* **************************************** * Name: TuSetTrack * Purpose: To turn Tracking on and off. While tracking is on * all work the user does and all feedback the user receives * is kept. While Tracking is off only the most recent work is kept. * Input * Parameters: int TrackStatus * TUT_TRACK_ON: Turn Tracking On * TUT_TRACK_OFF: Turn Tracking Off * Output * Parameters: none * Function Return * Variables: Previous Trace Status Value * TUT_TRACK_ON * TUT_TRACK_OFF * * TUT_ERR_INVALID_TRACK_STATUS * Notes: **************************************** */ extern “C” { long _export WINAPI TuSetTrack(int TrackStatus); }
[0097] Simulation Engine
[0098] The idea is for the designer to model the task that he wants a student to accomplish using an Excel spreadsheet. Then, have an algorithm or engine that reads all the significant cells of the spreadsheet and notifies the Intelligent Coaching Agent with the appropriate information (SourceItemID, TargetID and Attribute). This way, the spreadsheet acts as a central repository for student data, contains most of the calculations required for the task and in conjunction with the engine handles all the communication with the ICA. The task is self contained in the spreadsheet, therefore the designers no longer need a graphical user interface to functionally test their designs (smart spreadsheet. Once the model and feedback for it are completely tested by designers, developers can incorporate the spreadsheet in a graphical user interface, e.g., Visual Basic as a development platform. The simulation spreadsheet is usually invisible and populated using functions provided by the engine. It is very important that all modifications that the ICA needs to know about go through the engine because only the engine knows how to call the ICA. This significantly reduced the skill level required from programmers, and greatly reduced the time required to program each task. In addition, the end-product was less prone to bugs, because the tutor management was centralized. If there was a tutor problem, we only had to check on section of code. Finally, since the simulation engine loaded the data from a spreadsheet, the chance of data inconsistency between the tutor and the application was nil.
[0099] [0099]FIG. 25 is a block diagram setting forth the architecture of a simulation model in accordance with a preferred embodiment. The Simulation Object Model consists of a spreadsheet model, a spreadsheet control object, a simulation engine object, a simulation database, input objects, output objects, list objects and path objects. The first object in our discussion is the Spreadsheet object. The Spreadsheet is the support for all simulation models. A control object that is readily integrated with the Visual Basic development plat. The control supports printing and is compatible with Microsoft Excel spreadsheets. With that in mind, designers can use the power of Excel formulas to build the simulation. The different cells contained in the spreadsheet model can be configured as Inputs, Outputs or Lists and belong to a simulation Path. All cells in the spreadsheet that need to be manually entered by the designer or the student via the GBS application are represented by input objects. Every input has the following interface:
Field Data Name Type Description InputID long Primary Key for the table TaskID long TaskID of the task associated with the input PathID long PathID of the path associated with the input InputName string*50 Name of the input InputDesc string*255 Description of the input ReferenceName string*50 Name of the spreadsheet cell associated with the input TutorAware boolean Whether the ICA should be notified of any changes to the input SourceItemID long SourceItemID if input is a distinct input; 0 if input is a drag drop input TargetID long TargetID of the input Row long Spreadsheet row number of the input → speed optimization Column long Spreadsheet column number of the input → speed optimization SheetName string*50 Sheet name were the input is located → speed optimization
[0100] This information is stored for every input in the Input table of the simulation database (ICASim.mdb). Refer to the example below. When designers construct their simulation model, they must be aware of the fact that there are 2 types of Inputs: Distinct Input & Drag & Drop Input. The Distinct Input consists of a single spreadsheet cell that can be filled by the designer at design time or by the GBS application at run time via the simulation engine object's methods. The purpose of the cell is to provide an entry point to the simulation model. This entry point can be for example an answer to a question or a parameter to an equation. If the cell is TutorAware (all inputs are usually TutorAware), the ICA will be notified of any changes to the cell. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the input information i.e., SourceItemID, TargetID and null as Attribute. This message is to advise the ICA to remove this information from its memory. An ICANotifyCreate message with the input information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message is to advise the ICA to add this information to its memory. A Distinct Input never requires that a user answer a mathematics question.
[0101] These are the steps required to configure that simulation: Define a name for cell C 2 in Excel. Here we have defined “Distinct_Input”. In the ICA, define a task that will be assigned to the simulation. Ex: a TaskID of 123 is generated by the ICA. In the ICA, define a Target for the input. Ex: a TargetID of 4001 is generated by the ICA. In the ICA, define a SourceItem for the input. Ex: a SourceItemID of 1201 is generated by the ICA. Associate the input to a path (refer to Path object discussion). Add the information in the Input table of the simulation engine database. A record in an Input table is presented below.
InputID: 12345 TaskID: 123 PathID: 1234 InputName: Question 1 input InputDesc: Distinct input for Question 1 ReferenceName: Distinct_Input TutorAware: True SourceItemID 1201 TargetID: 4001 Row: 2 Column: 3 SheetName: Sheet1
[0102] The Row, Column and SheetName are filled in once the user clicks “Run Inputs/Outputs”. The simulation engine decodes the defined name (Reference Name) that the designer entered, and populates the table accordingly. This is an important step. We had several occasions when a designer would change the layout of a spreadsheet, i.e., move a defined name location, then forget to perform this step. As such, bizarre data was being passed to the tutor; whatever data happened to reside in the old row and column. Once the configuration is completed, the designer can now utilize the ICA Utilities to test the simulation.
[0103] The drag & drop input consist of two consecutive spreadsheet cells. Both of them have to be filled by the designer at design time or by the GBS application at run time via the simulation engine object's methods. This type of input is used usually when the user must choose one answer among a selection of possible answers. Drag & drop inputs are always TutorAware. The left most cell contains the SourceItemID of the answer picked by the user (every possible answer needs a SourceItemID) and the rightmost cell can contain a numeric value associated to that answer. You need to define a name or ReferenceName in the spreadsheet for the rightmost cell. ICA will be notified of any changes to either one of the cells. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the input information i.e., SourceItemID before the change occurred, TargetID of the input and the Attribute value before the change occurred. An ICANotifyCreate message with the input information i.e., SourceItemID after the change occurred, TargetID of the input and the Attribute value after the change occurred.
[0104] These are the steps required to configure that section of the simulation: Define a name for cell C 11 in Excel. Here we have defined “DragDrop_Input”; Let's use the same TaskID as before since Question 2 is part of the same simulation as Question 1. Ex: TaskID is 123; In the ICA, define a Target for the input. Ex: a TargetID of 4002 is generated by the ICA; In ICA, define a SourceItem for every possible answer to the question. Ex: SourceItemIDs 1202 to 1205 are generated by the ICA; Associate the input to a path (refer to Path object discussion); and Add the information in the Input table of the simulation engine database. A record in the Input table in accordance with a preferred embodiment is presented below.
InputID: 12346 TaskID: 123 PathID: 1234 InputName: Question 2 input InputDesc: Drag & Drop input for Question 2 ReferenceName: DragDrop_Input TutorAware: True SourceItemID 0*** TargetID: 4002 Row: 11 Column: 3 SheetName: Sheet1
[0105] The list object consists of one cell identifying the list (cell # 1 ) and a series of placeholder rows resembling drag & drop inputs (cells # 1 . 1 - 1 .n to cells #n. 1 -n.n). The list is used usually when the user must choose multiple elements am selection of possible answers. Cell # 1 must have a uniquely defined name also called the list name. Cells # 1 . 1 to #n. 1 can contain the SourceItemID of one possible answer picked by the user (every possible answer needs a SourceItemID). The content of these cells must follow this format: ˜ListName˜SourceItemID. Cells # 1 . 2 to #n. 2 will hold the numeric value (attribute) associated with the SourceItemID in the cell immediately to the left. Cells # 1 . 3 - 1 .n to #n. 3 -n.n are optional placeholders for data associated with the answer. KEY NOTE: When implementing a list object the designer must leave all the cells under #n. 1 to #n.n blank because this range will shift up every time an item is removed from the list.
Data Field Name Type Description ListID long Primary Key for the table TaskID long TaskID of the task associated with the list PathID long PathID of the path associated with the list ListName string*50 Name of the list ListDesc string*255 Description of the list ReferenceName string*50 Name of the spreadsheet cell associated with the list TutorAware boolean Whether the ICA should be notified of any changes to the list TargetID long TargetID of the output TotalColumns long Total number of data columns Row long Spreadsheet row number of the output → speed optimization Column long Spreadsheet column number of the output → speed optimization SheetName string*50 Sheet name were the input is located → speed optimization
[0106] Use of a list is demonstrated by continuing our math test. The math question in this example invites the user to select multiple elements to construct the answer. These are the steps required to configure that section of the simulation. FIG. 26 illustrates the steps for configuring a simulation in accordance with a preferred embodiment. Define a name for cell C 23 in Excel. Here we have defined “The _List”. Let's use the same TaskID as before since Question 3 is part of the same simulation as Question 1 and 2. Ex: TaskID is 123. In the ICA, define a Target for the list. Ex: a TargetID of 4006 963 is generated by the ICA. In the ICA, define a SourceItem for every item that could be placed in the list. Ex: the following SourceItemIDs 1209 , 1210 , 1211 , 1212 , 1213 , 1214 are generated by the ICA. Associate the list to a path (refer to Path object discussion). Add the information in the List table of the simulation engine database.
[0107] A record in the List table in accordance with a preferred embodiment is presented in the table appearing below.
ListID: 12346 TaskID: 123 PathID: 1234 ListName: Question 3 list ListDesc: List for Question 3 ReferenceName: The_List TutorAware: True TargetID: 4006 TotalColumns: 1 Row: 23 Column: 3 SheetName: Sheet1
[0108] All cells in the spreadsheet that are result of calculations (do not require any external input) can be represented by output objects. Every output has an interface as outlined in the table below.
Data Field Name Type Description OutputID long Primary Key for the table TaskID long TaskID of the task associated with the output PathID long PathID of the path associated with the output OutputName string*50 Name of the output OutputDesc string*255 Description of the output ReferenceName string*50 Name of the spreadsheet cell associated with the output TutorAware boolean Whether the CA should be notified of any changes to the output SourceItemID long SourceItemID of the output TargetID long TargetID of the output Row long Spreadsheet row number of the output → speed optimization Column long Spreadsheet column number of the output → speed optimization SheetName string*50 Sheet name were the input is located → speed optimization
[0109] All this information is stored for every output in the Output table of the simulation database (ICASim.mdb). When designers construct their simulation model, they must be aware of the fact that there is only 1 type of Outputs: the Distinct Output. A Distinct Output consists of one and only one spreadsheet cell that contains a formula or a result of calculations. The existence of Output cells is the main reason to have a simulation model. If the cell is TutorAware, the ICA will be notified of any changes to the cell when all outputs are processed otherwise the ICA will be unaware of any changes. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the output information i.e., SourceItemID, TargetID and null as Attribute. This message is to advise the ICA to remove this information from its memory. An ICANotifyCreate message with the output information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message is to advise the ICA to add this information to its memory. As opposed to Distinct Inputs and Drag & Drop Inputs which notify the ICA on every change, Distinct Outputs are processed in batch just before asking the ICA for feedback. To notify the ICA of the total dollar amount of the items in the list. We definitely need a Distinct Output for that. The output will contain a sum formula. Define a name for cell C 24 in Excel. Here we have defined “Distinct_Output”. Let's use the same TaskID as before since Question 3 is part of the same simulation as Question 1 and 2. Ex: TaskID is 123 . In the ICA, define a Target for the output. Ex a TargetID of 4005 is generated by the ICA. In the ICA, define a SourceItem for the output. Ex: a SourceItemID of 1215 is generated by the ICA. Associate the output to a path (refer to Path object discussion). Add the information in the Output table of the simulation engine database.
[0110] A record in an Output table in accordance with a preferred embodiment is presented below.
OutputID: 12347 TaskID: 123 PathID: 1234 OutputName: Question 3 output OutputDesc: Distinct Output for Question 3 ReferenceName: Distinct_Output TutorAware: True SourceItemID 1215 TargetID: 4005 Row: 24 Column: 6 SheetName: Sheet1
[0111] Paths are used to divide a simulation model into sub-Simulations meaning that you can group certain inputs, outputs and lists together to form a coherent subset or path. Every path has the following interface:
Field Name Data Type Description PathID long Primary Key for the table TaskID long TaskID of the task associated with the path PathNo long Numeric value associated to a path PathName string*50 Name of the path PathDesc string*255 Description of the path
[0112] All this information is stored for every path in the path table of the simulation database (ICASim.mdb).
[0113] The simulation engine is the interface between the model, the simulation database and the Intelligent Coaching Agent. The simulation engine is of interest to the designer so that he can understand the mechanics of it all. But it is the developer of applications using the engine that should know the details of the interface (methods & properties) exposed by the engine and the associated algorithms. Once the designer has constructed the simulation model (Excel Spreadsheet) and configured all the inputs, outputs & lists, he is ready to test using the test bench included in the ICA Utilities (refer to ICA Utilities documentation). The developer, in turn, needs to implement the calls to the simulation engine in the GBS application he's building. The following list identifies the files that need to be included in the Visual Basic project to use the simulation workbench:
wSimEng.cls Simulation Engine class wSimEng.bas Simulation Engine module (this module was introduced only for speed purposes because all the code should theoretically be encapsulated in the class) wConst.bas Intelligent Coaching Agent constant declaration wDeclare.bas Intelligent Coaching Agent DLL interface wlca.cls Intelligent Coaching Agent class wlca.bas Intelligent Coaching Agent module (this module was introduced only for speed purposes because all the code should theoretically be encapsulated in the class)
[0114] To have a working simulation, a developer places code in different strategic areas or stages of the application. There's the Initial stage that occurs when the form containing the simulation front-end loads. This is when the simulation model is initialized. There's the Modification stages that take place when the user makes changes to the front-end that impacts the simulation model. This is when the ICA is notified of what's happening. There's the Feedback stage when the user requests information on the work done so far. This is when the simulation notifies the ICA of all output changes. Finally, there's the Final stage when the simulation front-end unloads. This is when the simulation is saved to disk.
[0115] The different stages of creating a simulation, including the Visual Basic code involved, are presented below. Initial stage; 1. Creating the ICA & the simulation engine object: Code: Set moSimEngine=New classSimEngine; Set moICA=New classICA; Description: The first step in using the simulation engine is to create an instance of the class classSimEngine and also an instance of the class classICA. Note that the engine and ICA should be module level object “mo” variables. 2. Loading the simulation; Code: IRet=moSimEngine.OpenSimulation(App.Path & DIR_DATA & FILE_SIMULATION, Me.bookSimulation); IRet=moSimEngine.LoadSimulation(mIICATaskID, App.Path & DIR_DATABASE & DB_SIMULATION, 1 ); Description: After the object creation, the OpenSimulation and LoadSimulation methods of the simulation engine object must be called. The OpenSimulation method reads the specified Excel 5.0 spreadsheet file into a spreadsheet control. The LoadSimulation method opens the simulation database and loads into memory a list of paths, a list of inputs, a list of outputs and a list of lists for the specific task. Every method of the simulation engine will return 0 if it completes successfully otherwise an appropriate error number is returned. 3. Initializing and loading the Intelligent Coaching Agent; Code:IRet=moICA.Initialize(App.Path & “\” & App.EXEName & “.ini”, App.Path & DIR_DATABASE, App.Path & DIR_ICADOC, App.Path & “\”); IRet=moICA.LoadTask(mIICATaskID, ICAStudentStartNew); Description: The simulation engine only works in conjunction with the ICA. The Initialize method of the ICA object reads the application .ini file and sets the Tutor32.dII appropriately. The LoadTask method tells the ICA (Tutor32.dII) to load the tut document associated to a specific task in memory. From that point on, the ICA can receive notifications. Note: The .tut document contains all the element and feedback structure of a task. Ex: SourcePages, SourceItems, TargetPages, Targets, etc . . . 4. Restoring the simulation; Code: <<Code to reset the simulation when starting over>>; <<Code to load the controls on the simulation front-end>>; IRet=moSimEngine.RunInputs(sPaths, True); IRet=moSimEngine.RunOutputs(sPaths, True); IRet=moSimEngine.RunLists(sPaths, True); Call moICA.Submit( 0 ); Call moICA.SetDirtyFlag( 0 , False); Description: Restoring the simulation involves many things: clearing all the inputs and lists when the user is starting over; loading the interface with data from the simulation model; invoking the RunInputs, RunOutputs and RunLists methods of the simulation engine object in order to bring the ICA to it's original state; calling the Submit method of the ICA object with zero as argument to trigger all the rules; calling the SetDirtyFlag of the ICA object with 0 and false as arguments in order to reset the user's session. Running inputs involves going through the list of TutorAware inputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every input. Running lists involves going through the list of TutorAware lists and notifying the ICA of the SourceItemID, TargetID and Attribute value of every item in every list. The TargetID is unique for every item in a list.
[0116] Running outputs involves going through the list of TutorAware outputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every output. Modification stage 1. Reading inputs & outputs; Code: Dim sDatarray( 2 ) as string; Dim vAttribute as variant; Dim ISourceItemID as long; Dim ITargetID as long; IRet=moSimEngine.ReadReference(“Distinct_Input”, vAttribute, ISourceItemID, ITargetID, sDataArray)
[0117] Description: The ReadReference method of the simulation object will return the attribute value of the input or output referenced by name and optionally retrieve the SourceItemID, TargetID and related data. In the current example, the attribute value, the SourceItemID, the TargetID and 3 data cells will be retrieved for the input named Distinct_Input.
[0118] Description: The simulation engine object provides basic functionality to manipulate lists.
[0119] The ListAdd method appends an item(SourceItemID, Attribute, Data array) to the list. Let's explain the algorithm. First, we find the top of the list using the list name. Then, we seek the first blank cell underneath the top cell. Once the destination is determine, the data is written to the appropriate cells and the ICA is notified of the change. The ListCount method returns the number of items in the specified list. The algorithm works exactly like the ListAdd method but returns the total number of items instead of inserting another element. The ListModify method replaces the specified item with the provided data. Let's explain the algorithm. First, we find the top of the list using the list name. Second, we calculate the row offset based on the item number specified. Then, the ICA is notified of the removal of the existing item. Finally, the data related to the new item is written to the appropriate cells and the ICA is notified of the change. The ListDelete method removes the specified item. The algorithm works exactly like the ListModify method but no new data is added and the cells (width of the list set by ‘Total Columns’) are deleted with the ‘move cells up’ parameter set to true. Keep this in mind, as designers often enter the wrong number of columns in the Total Columns parameter. When they overestimate the Total Columns, ListDelete will modify portions of the neighboring list, which leads to erratic behavior when that list is displayed.
[0120] System Dynamics in Accordance with a Preferred Embodiment
[0121] To use system dynamics models in the architecture, an engine had to be created that would translate student work into parameters for these models. A complex system dynamics model to interact with an existing simulation architecture is discussed below. The system dynamics model provides the following capabilities. Allow designers to build and test their system dynamics models and ICA feedback before the real interface is built. Reduce the programming complexity of the activities. Centralize the interactions with the system dynamics models. System Dynamics Engine As with the simulation engine, the designer models the task that he/she wants a student to accomplish using a Microsoft Excel spreadsheet. Here, however, the designer also creates a system dynamics model (described later). The system dynamics engine will read all of the significant cells within the simulation model (Excel) and pass these values to the system dynamics model and the ICA. After the system dynamics model runs the information, the output values are read by the engine and then passed to the simulation model and the ICA.
[0122] [0122]FIG. 27 is a block diagram presenting the detailed architecture of a system dynamics model in accordance with a preferred embodiment. Once the simulation model, system dynamics model and feedback are completely tested by designers, developers can incorporate the spreadsheet in a graphical user interface, e.g., Visual Basic as a development platform. FIG. 27 illustrates that when a student completes an activity, the values are passed to the system dynamics engine where the values are then passed to the system dynamics model (as an input), written to the simulation model and submitted to the ICA. When the system dynamics model is played, the outputs are pulled by the engine and then passed to the simulation model and the ICA. Note that the simulation model can analyze the output from the system dynamics model and pass the results of this analysis to the ICA as well. The simulation model can then be read for the output values and used to update on-screen activity controls (such as graphs or reports).It is very important that all modifications that the ICA and system dynamics model need to know about go through the engine because only the engine knows how to call these objects. This significantly reduces the skill level required from programmers, and greatly reduces the time required to program each task. In addition, the end-product is less prone to bugs, because the model and tutor management will be centralized. If there is a problem, only one section of code needs to be checked. Finally, since the engine loads the data from the spreadsheet, the chance of data inconsistency between the ICA, the system dynamics model and the application is insignificant.
[0123] The system dynamics model generates simulation results over time, based on relationships between the parameters passed into it and other variables in the system. A system dynamics object is used to integrate with Visual Basic and the spreadsheet object. The object includes logic that controls the time periods as well as read and write parameters to the system dynamics model. With Visual Basic, we can pass these parameters to and from the model via the values in the simulation object. The system dynamics object also controls the execution of the system dynamics model. What this means is that after all of the parameter inputs are passed to the system dynamics model, the engine can run the model to get the parameter outputs. The system dynamics object allows for the system dynamics models to execute one step at a time, all at once, or any fixed number of time periods. When the system dynamics model runs, each step of the parameter input and parameter output data is written to a ‘backup’ sheet for two reasons. First, the range of data that is received over time (the model playing multiple times) can be used to create trend graphs or used to calculate statistical values. Second, the system dynamics model can be restarted and this audit trail of data can be transmitted into the model up to a specific point in time. What this means is that the engine can be used to play a simulation back in time. When any event occurs within the system dynamics engine, a log is created that tells the designers what values are passed to the simulation model, system dynamics model and ICA as well as the current time and the event that occurred. The log is called “SysDyn.log” and is created in the same location as the application using the engine. As with the spreadsheet object, the system dynamics object allows a large amount of the calculations to occur in the system dynamics model and not in the activity code, again placing more control with the activity designers. Model objects are used to configure the system dynamics models with regard to the time periods played. Models are what the parameter inputs and parameter outputs (discussed later) relate to, so these must be created first. Every model has the following application programming interface:
Data Field Name Type Description ModelID Long Primary Key for the table TaskID Long TaskID of the task associated with the model ModelName String* Name of the model (informational purposes) 50 ModelDesc String* Description of the model (informational 50 purposes) SysDynModel String* Filename of the actual system dynamics model 50 Start Long Start time to play modal Stop Long Stop time to play model Step Long Interval at which to play one model step and record data
[0124] This information is stored in the model table of the simulation database (ICASim.mdb). All of the values that will need to be manually entered by the student that are passed into the system dynamics model are configured as parameter inputs (PInputs) objects. Every PInput has an interface as detailed below.
Field Name Data Type Description PinputID long Primary Key for the table TaskID long TaskID of the task associated with the parameter input ModelID long ID of the model associated with the parameter input InputName string*50 Name of the parameter input (informa- tional purposes) lnputDesc string*255 Description (informational purposes) ReferenceName string*50 Name of the spreadsheet cell associated with the parameter input 1 SimReferenceName string*50 Name of the associated parameter in the system dynamics model TutorAware boolean Whether the ICA should be notified of any input CHANGES SourceItemID ong SourceItemID of the parameter input TargetID long TargetID of the parameter input Row long Spreadsheet row number of the param- eter input Column long Spreadsheet column number of the parameter input SheetName string*50 Sheet name were the parameter input is located
[0125] All of this information is stored for every parameter input in the PInput table of the simulation database (ICASim.mdb). PInputs consist of one spreadsheet cell that can be populated by a designer at design time or by the GBS application at run time via the system dynamics engine object's methods. The purpose of the cell is to provide an entry point to the simulation and via system dynamics models. An example of an entry point would be the interest rate parameter in the interest calculation example. The ICA is notified of any changes to the cell when an appropriate activity transpires. When the ICA is notified of a change two messages are sent to the ICA. The first is an ICANotifyDestroy message with the parameter input information i.e., SourceItemID, TargetID and null as an attribute. This message is sent to inform the ICA to remove information from its memory. The second message is an ICANotifyCreate message with the parameter input information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message advises the ICA to add this information to its memory. A PInput table record in accordance with a preferred embodiment is presented below.
PInputID: 12345 TaskID: 123 ModelID: 1 InputName: Interest Rate input InputDesc: Interest Rate input into interest calculation model ReferenceName: Interest_Rate SimReferenceName Param_Interest_Rate TutorAware: True SourceItemID: \1201 TargetID: 4001 Row: 6 Column: 3 SheetName: Sheet1
[0126] Once the configuration is completed, the designer can also use the ICA Utilities to test the simulation. The Row, Column and SheetName values are automatically populated when the designer runs the parameters in the System Dynamics Workbench in the ICA Utilities. The following information provides details describing the interaction components in accordance with a preferred embodiment.
Title Description Procedural Tasks which require the construction of some kind of report tasks (w/drag with evidence dragged and dropped to justify conclusions drop) Procedural New task designs that are procedural in nature, have very tasks (w/o little branching, and always have a correct answer. drag drop) Ding Dong Tasks that interrupt the student while working on something task else. This template includes interviewing to determine the problem, and a simple checkbox form to decide how to respond to the situation. Analyze and Most commonly used for static root cause analysis, or Decide identification tasks. Developed on SBPC as a result of 3 (ANDIE) projects of experience redesigning for the same skill. task Evaluate Used for tasks that require learner to evaluate how different Options options meet stated goals or requirements. Developed at (ADVISE) SBPC after 4 projects experience redesigning for the same skill. Does not allow drag drop as evidence. Run a Time based simulation where student “chooses own company adventure”. Each period the student selects from a pre- task determined list of actions to take. Developed on SBPC as a simplified version of the BDM manage task. Use a model When user needs to interact with a quantitative model to task perform what if analysis. May be used for dynamic root cause analysis - running tests on a part to analyze stress points. ICA Developed on BDM to mimic interaction styles from Coach Dynamic and ILS EPA. Supports dynamic-rule based branching - will Meeting scale to support interactions like EnCORE defense meetings Task and YES. Manage Time based simulation where student manages resources. Task Human Resources Management, managing a budget, manage an FX portfolio. QVID Static Developed on Sim2 to support agenda-driven meetings Meeting where user is presented with up to 5 levels of follow-up Task questions to pursue a line of questioning. As they ask each question, it's follow-ups appear. Flow Chart Will support most VISIO diagrams. Developed on Sim2 to Task support simple flow chart decision models. QVID Static flat list of questions to ask when interviewing some- Gather Data one. Not used when interviewing skills are being taught Component (use QVID Static meeting task). Supports hierarchical questions and timed transcripts. Journalize Created to support simple journal entry tasks with up to 2 Task accounts per debit or credit. New A new task that requires a simulation component Complex Task
[0127] The system dynamics engine is the interface between the simulation model, the system dynamics model, the simulation database and the Intelligent Coaching Agent. The system dynamics engine is of interest to the designer so that she can understand the mechanics of it. Once the designer has constructed the simulation model (Excel Spreadsheet), built the system dynamics model (PowerSim) and configured all of the parameter inputs and parameter outputs, a test can be performed using the workbench included in the ICA Utilities (refer to ICA Utilities documentation). The developers, in turn, need to implement the calls to the system dynamics engine in the GBS application that is being built. The following list identifies the files that need to be included in the Visual Basic project to use the system dynamics engine.
WSysDynEng.cls System dynamics Engine class wSysDynEng.bas System dynamics Engine module (this module was introduced only for speed purposes because all the code should theoretically be encapsulated in the class) wConst.bas Intelligent Coaching Agent constant declaration wDeclare.bas Intelligent Coaching Agent DLL interface wlca.cls Intelligent Coaching Agent class wlca.bas Intelligent Coaching Agent module (this module was introduced only for speed purposes because all of the code should theoretically be encapsulated in the class)
[0128] To utilize the system dynamics engine fully, the developer must place code in different strategic areas or stages of the application. Initial stage—the loading of the form containing the simulation front-end. This is when the simulation model and system dynamic engine are initialized. Modification stage—Takes place when the user makes changes to the front-end that impacts the simulation model PInputs). This is when the ICA is notified of what's happening. Run stage—The system dynamics model is run and parameter outputs are received. Feedback stage—The user requests feedback on the work that they have performed. This is when the simulation notifies the ICA of all output changes. Final stage—The simulation front-end unloads. This is when the simulation model is saved. These stages will be explained by including the Visual Basic code involved as well as a short description of that code.
[0129] Initial Stage Code in Accordance with a Preferred Embodiment
[0130] 1. Creating the ICA & the simulation engine objects: Code: Set moSysDynEngine=New classSysDynEngine; Set moICA=New classICA; Description: The first step in using the system dynamics engine is to create an instance of the classSysDynEngine class and also an instance of the classICA class. Note that the engine and ICA should be module level object “mo” variables. 2. Loading the simulation: Code: IRet=moSysDynEngine.OpenSimulation(FILE_SIM, Me.bookSim, True); IRet=moSysDynEngine.LoadSysDyn(mIICATaskID, DB_SIMULATION, 1); IRet=moSysDynEngine.LoadModel(MODEL_NAME,mbTaskStarted); Description: After the object creation, the OpenSimulation, LoadSimulation and LoadModel methods of the system dynamics engine object must be called. The OpenSimulation method reads the specified Excel 5.0 spreadsheet file (FILE_SIM) into a spreadsheet control (bookSim). The LoadSysDyn method opens the simulation database (DB_SIMULATION) and loads into memory a list of parameter inputs and a list of parameter outputs. The LoadModel method opens a system dynamics model (MODEL_NAME). Every method of the system dynamics engine will return 0 if it completes successfully otherwise an appropriate error number is returned. 3. Initializing and loading the Intelligent Coaching Agent; Code: IRet=moICA.Initialize(App.Path & “\” & App.EXEName & “.ini”, App.Path & DIR_DATABASE, App.Path & DIR_ICADOC, App.Path & “\”); IRet=moICA.LoadTask(mIICATaskID, ICAStudentStartNew); Description: The system dynamics engine only works in conjunction with the ICA. The Initialize method of the ICA object reads the application .ini file and sets the Tutor32.dII appropriately. The LoadTask method tells the ICA (Tutor32.dII) to load the .tut document associated to a specific task in memory. From that point on, the ICA can receive notifications. Note: The .tut document contains all the element and feedback structure of a task. Ex: SourcePages, SourceItems, TargetPages, Targets, etc . . . 4. Restoring the simulation—Code: IRet=moSysDynEngine.RunPInputs(MODEL_NAME, True); IRet=moSysDynEngine.RunPOutputs(MODEL_NAME, True); IRet=moSysDynEngine.PassPInputsAll; Call moICA.Submit( 0 ); Call moICA.SetDirtyFlag( 0 , False) Description: Restoring the simulation involves many things: clearing all of the parameter inputs and outputs when the user is starting over; loading the interface with data from the simulation model; invoking the PassPInputsAll method of the system dynamics engine object in order to bring the ICA to its original state; invoking the RunPInputs and RunPOutputs methods of the system dynamics engine object in order to bring the system dynamics model to it's original state; calling the Submit method of the ICA object to trigger the ICA to play all of the rules; calling the SetDirtyFlag of the ICA object to reset the user's session. Running parameters involves going through the list of TutorAware PInputs and POutputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every one.Modification Stage; 1. Reading parameter inputs & outputs; Code: Dim sDataArray( 2 ) as string; Dim vAttribute as variant; Dim ISourceItemID as long, ITargetID as long IRet=moSysDynEngine.ReadReference(“Input_Name”, vAttribute, ISourceItemID, ITargetID, sDataArray). Description: The ReadReference method of the system dynamics object will return the attribute value of the parameter input or output referenced by name and optionally retrieve the SourceItemID, TargetID and related data. In the current example, the attribute value, the SourceItemID, the TargetID and 3 data cells will be retrieved for the parameter input named Input_Name. 2. Modifying parameter inputs Code: Dim vAttribute as variant; Dim ISourceItemID as long; Dim sDataArray( 2 ) as string; vAttribute=9999; sDataArray( 0 )=“Data Cell #1”; sDataArray( 1 )=“Data Cell #2”; sDataArray( 2 )=“Data Cell #3”; IRet=moSysDynEngine.WriteReference(“Input_Name”, vAttribute, , sDataArray). Description: To modify a parameter input, call the WriteReference method of the system dynamics object and pass the PInput reference name, the new attribute value and optionally a data array (an additional information to store in the simulation model). The system dynamics engine notifies the ICA of the change. Run Stage 1. Playing the System Dynamics Model; Code: IRet=moSysDynEngine.PlayModel(SYSDYN_PLAYSTEP); IblCurrentTime.Caption=moSysDynEngine.CurrentTime; and IblLastTime.Caption=moSysDynEngine.LastTime; Description: Playing the system dynamics model is also handled by the system dynamics engine. There are three ways that the models can be played, all at once, one step at a time (shown above) or until a specific point in time. These are the parameters that are passed into the PlayModel method. Playing of the model generates the parameter output values and passes the Tutor Aware POutputs to the ICAT. The engine also keeps track of time and these values can be read using the CurrentTime and LastTime properties. 2. Jumping Back in a System Dynamics Model Code: IRet=moiCA.LoadTask(mIICATaskID, ICAStudentStartNew); IRet=moSysDynEngine.JumpBack(TIME_TO_JUMP_TO). Description: Because the system dynamics engine writes backup copies of the parameters passed to and from it, it can start over and resubmit these values back to the system dynamics model until a given period of time. To do this, the code would need to restart the ICA and then call the system dynamics engine to jump back to a given time (TIME_TO_JUMP_TO). Feedback stage 1. Triggering the ICA Rule engine; Code: IRet=moICA.Submit(lCoachID); Description: Once the simulation has been processed, the Submit method of the ICA object must be called to trigger all the rules and deliver the feedback. This feedback will be written by the Tutor32.dII to two RTF formatted files. One file for previous feedback and one file for the current feedback.
[0131] ICA Configuration in Accordance with a Preferred Embodiment
[0132] [0132]FIG. 28 is an overview diagram of the logic utilized for initial configuration in accordance with a preferred embodiment. Since the structure of the feedback is the same as other on-line activities, the ICA can also be configured in the same manner. For ease of creation and maintenance of ICA feedback, it is recommended that the feedback is constructed so that only one rule fires at any point in time. Note that the organization of the example is one of many ways to structure the feedback. Step 1: Create a map of questions and follow-up questions; Before designers start configuring the ICA, they should draw a map of the questions, videos and follow-up questions that they wish to use in the on-line meeting. This will give them a good understanding of the interactions as they configure the ICA. Step 2: Create a coach; All feedback is given by a coach. Create a specific coach for the on-line meeting. Step 3: Create the Source Items and Targets
[0133] Every question will have one Source Item ( 1 ) and Target ( 2 ) associated with it. These will be used by the ICA to show videos and follow-up questions. For organizational purposes and ease of reading, it is recommended that each Source Page (“0 Intro”) contain all of the follow up questions (“Intro Q1”, “Intro Q2”, “Intro Q3”). Targets can be created one per Source Item (shown here) or one per many Source Items. This is not very important, so long as there are distinct Source Item and Target associations. Once the Source Items and Targets have been created, associate them into SourceItemTargets ( 3 ) and give them a relevance of one. These are the unique identifiers which the ICA will use to fire rules and to provide feedback to the student. Step 4: Create the Parent Header (Video Information) FIG. 29 is a display of video information in accordance with a preferred embodiment. Feedback (Coach Items) are organized into Target Groups ( 1 ). In FIG. 29, each on-line question has one Target Group for ease of maintenance. Each TargetGroup must have at least one related Target ( 4 ). These are the SourceItemTarget mappings that were made at the end of Step 3. Next, Rules ( 2 ) are created to fire when the SourceItemTarget is mapped (a question is clicked). Coach Items ( 3 ) are associated to a rule and represent the feedback which will be shown if the rule is fired. The ICA Utilities incorporate business simulation into a multimedia application. What this means is that there is now a middle layer between the application and the ICAT. These utilities, along with the simulation engine (described later), allow the architecture to be a front end to the simulation. Now, any changes to a simulation model do not need to be incorporated into code. The ICA Utilities and simulation engine work with simulation models created in Microsoft Excel. After the model is created, the designer uses the Defined Name function in Excel to flag specific cells that are to be used by the application and the ICA Utilities in accordance with a preferred embodiment. FIG. 30 illustrates an ICA utility in accordance with a preferred embodiment. The ICA Utilities consist of six utilities that work with the Intelligent Coaching Agent Tool (ICAT) to incorporate business simulation with the multimedia application. | A system is disclosed that provides a goal based learning system utilizing a rule based expert training system to provide a cognitive educational experience. The system provides the user with a simulated environment that presents a business opportunity to understand and solve optimally. Mistakes are noted and remedial educational material presented dynamically to build the necessary skills that a user requires for success in the business endeavor. The system utilizes an artificial intelligence engine driving individualized and dynamic feedback with synchronized video and graphics used to simulate real-world environment and interactions. Multiple “correct” answers are integrated into the learning system to allow individualized learning experiences in which navigation through the system is at a pace controlled by the learner. A robust business model provides support for realistic activities and allows a user to experience real world consequences for their actions and decisions and entails realtime decision-making and synthesis of the educational material. A store management tutorial system is enabled for providing active coaching on aspects of inventory management, stocking, advertising, return on revenue, markdown, assortment strategy and other aspects of retail management. Techniques for process sensitive help are also integrated into the system to provide contextual examples to guide a user in performing a task. | 8 |
FIELD OF THE INVENTION
The present invention relates to the microelectronics field, and to be more specific to that of techniques of hybridization by means of bumps of two heterogeneous components, also known as soldering bumps. It is connected therefore to the general field of micro-components, more conventionally denoted electronic chips, but also capable of being applied to micro-sensors, micro-actuators, such as Micro Electro Mechanical Systems (MEMS), and also to optoelectronic components, such as Vertical Cavity Semi Conductor Emitting Lasers (VCSEL).
Under the invention, the temu component is taken to mean an electronic sensor, such as an electronic chip, an electrical or electronic circuit support, or a passive electrical component such as a protective cover, or even a physical quantity sensor.
BACKGROUND OF THE INVENTION
The micro-components concerned in the context of the present invention are conventionally deposited on a substrate of an appropriate type, for example the semi-conductor type (single crystal silicon, sapphire, etc.) for electronic components.
The substrate is provided with electrically conductive tracks, that are made out of aluminium for example, which radiate from the micro-component towards the periphery of the substrate, in order to make it possible, not only to supply to the component any electrical power that might be required, but also and above all to process the operation of the signals that the component is called upon to generate, while even controlling the functions it incorporates.
To join different components to each other, one of the techniques in widespread use today is that of flip-chip hybridization by means of solder welding balls or bumps. This technology includes in brief:
depositing onto one or more wettable surfaces, placed on one of the components for joining, the material constituting the welding bumps in an appropriate quantity; providing the other component for hybridizing with surfaces that are wettable by the welding material, with the surfaces being provided substantially in line with the surfaces of the first component when the second component is transferred onto the first; depositing a flow of material in liquid form, the flow performing a chemical function of deoxidation and prevention of reoxidation during soldering, a thermal function enabling the transfer of heat, and a physical function enabling surface tensions to be reduced and thereby promoting the formation of the bumps themselves; then, bringing the wettability surface of the second component into contact with the soldering material so deposited; and finally, raising the temperature until a temperature is reached higher than the fusion temperature of the material constituting the bumps in order to obtain the fusion thereof until the required result is achieved, namely the hybridization of the first component to the second component, with bumps creating a mechanical and/or electrical link between the wettable surfaces of each of the components, with at least the wettable surfaces being themselves connected to the conductive tracks provided thereon.
Thus, during the assembly process, the soldering material constituting the bumps takes on the shape of a ball.
Because of the great number of components capable of being hybridized on a single substrate surface, particular care must be paid to the problem of the mechanical strength of the circuits produced. In order to optimize the mechanical strength, there is a known technique of coating the electronic components obtained after hybridization.
A prior art coating technique has in fact been shown in relation to FIGS. 1 and 2 .
This coating method may include depositing a calibrated drop 5 of coating substance, such as a coating resin, onto the substrate 3 or read circuit of a component 1 , in proximity to the hybridization region of a chip 2 to the substrate.
The calibrated drop 5 of resin is deposited near to the electronic component hybridized by the bumps with the drop of resin migrating by capillarity action under the electronic component or chip 2 added by hybridization. In other words, the resin will occupy the volume defined between the electronic component and the substrate and come to surround the hybridization bumps 6 . The coating 7 guarantees the mechanical strength over time of the component so obtained after hybridization.
The coating technique, however, does encounter a certain number of difficulties.
In the first place, in order to implement the capillarity effect while ensuring the effective migration of the coating resin, the drop of resin must be deposited sufficiently close to the hybridized component in order to generate a surface tension effect by capillarity action.
In the same way, the volume of resin must be large enough to fill completely the space defined between the component 2 and the substrate 3 . However, this quantity must not be excessive either, in order to prevent the resin from spreading beyond the substrate, which might, if this were to happen, prevent the hybridization of other components in adjacent proximity.
An improvement to this coating technique has been described, for example in the document FR 2 704 691. In brief, this includes the positioning a carpet of balls in proximity to the bumps intended to hybridize the component on the substrate, the coating resin being deposited onto the carpet of balls with the latter ensuring the migration of the resin by capillarity action towards the hybridized component, thereby resolving the problem inherent in the proximity in a straightforward way.
However, this improvement does not resolve the problem of controlling the spread of the coating resin beyond the hybridized component, where an excess of resin is always able to uncontrollably spread elsewhere on the substrate. To escape this difficulty, a proposal has also been made for the implementation of a seam of adhesive that is peripheral relative to the component with the seam acting as a barrier and the coating resin being deposited inside the seam.
However, this technique also comes up against various drawbacks among which is the fact that this method must be carried out in two stages, which is detrimental to the manufacturing time.
Moreover, implementing the seam consumes valuable surface area on the substrate, thereby reducing the capacity for bringing together and concentrating the necessary components on a single substrate.
The invention specifically sets out to find a solution for these different problems.
SUMMARY OF THE INVENTION
The invention thus applies, initially, to a method of coating the area of hybridization of a component constituted by two elements each associated with the other by means of a soldering material.
The method includes depositing a coating substance in close proximity to the component, also known as underfill resin in the technical field under consideration, which is capable of filling by capillarity action the volume defined between the hybridized elements of the component.
According to the invention, on the periphery of the hybridization area on the lower element of the component, an area of non-wettability in regards to the coating substance is defined by the deposition of a covering that is anti-wetting in regards to the substance, with the deposition being applied by Plasma Enhanced Chemical Vapour Deposition (PECVD).
In doing this, the non-wettability area provides a barrier relative to the coating substance, thereby avoiding any risk of dispersion of the coating substance over the lower element, and in general terms over the substrate on which the component is hybridized.
According to the invention, the anti-wetting covering, which is not very thick, is constituted for example by SiOC or C 4 F 8 .
According to one advantageous feature of the invention, a continuous surface is defined on the first element or substrate, in line with the hybridization area which is required to be coated, and intended to receive the coating substance.
The area with wetting in regards to the coating substance, is defined by the non-wetting area in regards the coating substance that is applied on or around the periphery thereof.
According to one feature of the invention, zone includes a first extension, located contiguous and in continuity with the wetting area, and intended to act as reception surface for the drop of coating substance.
According to another feature of the invention, the area also comprises a second extension, also contiguous and in continuity therewith, and intended to collect the excess coating substance, which is advantageously located opposite to the reception extension relative to the hybridized component that it is required to be coated.
In other words, in these two designs, the non-wettability area, which is peripheral to the hybridized component, has one or two extensions defining an area for receiving the coating substance and an area for collecting the excess coating substance respectively.
According to one particular feature of the invention, more specifically intended for optoelectronic components, a non-wettability surface relative to the coating substance is also defined on the first element or on the substrate on which the second element is hybridized, located in the hybridization area and in a particular area in which the presence of the coating substance is not required.
The design may be found in the context of optoelectronic components in respect of which it may be required to hybridize a laser, the substrate then being bored with a through orifice, to let the laser beam through or to receive an optical fibre.
According to another objective of the invention, the specified method can be used to convert wettability properties on the anti-wetting coating that is obtained. This wettability feature inversion is obtained, in compliance with the invention, by subjecting the anti-wetting covering to the action of a plasma or to the action of an ultra-violet radiation. To this end, after the elements constituting the component have been hybridized together and coated by the so-called “underfill” resin, in accordance with what has been described above, the assembly can then be coated with another resin, known in the field under consideration by the term “glob-top”, which confers excellent mechanical cohesion on the component.
In other words, this reversibility of the wettability properties enables components previously hybridized by “flip chip” to be coated by a coating resin or “glob-top” with good adhesion, and with the electrical contacts under the chip or under the hybridized element that has been coated with an underfill resin in a controlled way by using deposition barriers that are hydrophobic, and therefore, not able to be bonded effectively. Indeed, on depositions left hydrophobic, a “glob-top” coating would have poor adhesion, promoting incipient cracking.
It will be useful to recall that the wettability is reduced when the hydrophobic character is increased.
BRIEF DESCRIPTION OF THE DRAWINGS
The way in which the invention can be implemented, and the resulting advantages, will become clearer from the following embodiment examples, given for information purposes and non-restrictively, supported by the appended figures.
FIGS. 1 and 2 are diagram representations of a prior art coating principle.
FIG. 3 is a view from above of the method of coating a hybridized component in accordance with the invention.
FIG. 4 is a view from above similar to FIG. 3 of an alternative embodiment.
FIG. 5 shows the implementation of a coated hybridized optoelectronics component in accordance with the inventive method seen in cross-section,
FIG. 6 being a view from above.
FIG. 7 is a diagrammatic representation of a hybridized component in accordance with the invention, and implementing a linear laser array and a linear lens array in the context of an optronics component.
FIGS. 8 a , 8 b and 8 c set out to show the reversible character of the wettability properties of the coating applied in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
A description is given, in relation to FIGS. 3 and 4 , of a method of coating a component obtained after hybridization. This is based fundamentally on the principle of the migration of a coating resin or underfill resin 7 in the volume or space defined by the hybridized components 2 and 3 , thereby ensuring the mechanical strength of the hybridized component and the resistance in particular of the microbumps 6 subsequent to the different stresses that may be encountered by the sensor implementing the hybridized component.
The coating resin may consist of epoxy, but may also be selected from the group that includes acrylates and silicones.
To confine the coating resin in the inter-component space, the lower component, in the case in point the substrate 3 , is coated with a fine layer of material of non-wettability in regards to the coating substance, with the exception of the hybridization area.
A view from above is given in FIG. 3 of just the lower part of the component. The reference 4 shows conductive tracks, the reference 8 shows in broken lines the perimeter of the component and the reference 12 the area of confinement of the resin.
According to the invention, an area for the deposition 9 of the required quantity of coating resin is also defined, again by implementing the covering with non-wettability in regards to the coating resin. The confinement of the coating resin by the presence of the non-wettability covering for the whole periphery of the component, makes it certain that the coating resin will not migrate beyond the necessary surface, thereby allowing the prior art drawbacks to be overcome.
Because of the confinement of the coating resin, it becomes possible to increase the concentration of hybridized components on a single substrate since the problems related to the migration of the coating resin beyond the inter-component area are no longer encountered.
The covering with non-wettability in regards to the coating resin is not very thick, typically between 10 and 500 nm, and is constituted for example by SiOC or C 4 F 8 .
The covering is deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) from a precursor, Octamethylcyclotetrasiloxane (OMCTS) in the case in point and by using a carrier gas such as argon or hydrogen.
Depending on the power of the plasma, the pressure, the initial precursor concentration and the duration of the plasma deposition, the thickness of the deposited layer and the stoichiometry thereof. SiO x1 C y1 H z1 can be controlled. The material SiO x1 C y1 H z1 is of formulation such that 0.3≦x1≦0.4 and 0.15≦y1≦0.2 and 0.4≦z1≦0.55.
Quite clearly, the deposition method and corresponding treatments may be applied more generally to other types of siloxanes of a close formulation, such as for example tetraethylcyclotetrasiloxane (TNCTS).
The material may further be treated and transformed on the surface into a material with the general formulation SiO x2 C y2 H z2 , with x 2 >>x 1 , y 2 <<y 1 and z 2 <<z 1 , or more straightforwardly SiO x , in which x tends towards 2 in order to increase the value of its surface, while the polar energy induces a very strong wettability of liquids (contact angle of about 5° in respect of water), and a marked increase in adhesion and cellular development (moving from a generation time of 40 hours in respect of crude OMCTS to 20 hours in respect of the treated OMCTS).
The treatments used are either of the plasma type, namely helium plasma or oxygen plasmas O 2 , SF 6 +O 2 , CHF 3 +O 2 etc.), or of the UV type in ambient air or in an oxygen-enriched atmosphere.
The treatments in respect to this type of deposition therefore have the particular advantage of making wettable in regards to a substance an area that was initially non-wettable in regards to the substance. In other words, the initial low wettability or non-wettability property of the deposition becomes reversible.
This feature can advantageously be implemented in order to improve the adhesion of the covering resins, also known as “glop-top” in the technical field under consideration, to promote and optimize the mechanical cohesion of the component obtained after hybridization.
Thus, initially ( FIG. 8 a ), the deposition of the localized anti-wetting coating 10 , and for example SiO x1 C y1 H z1 controls by confinement the spread of the coating or underfill resin 5 , 7 under the component or hybridized element 2 , then in a second phase, the unit so obtained is subjected to the action of a plasma or ultra-violet radiation 21 ( FIG. 8 b ), tending to make the confinement covering wettable in regards to a covering or a coating or a “glob-top” resin 20 , thereby improving its properties of adhesion with the resin, in order to promote an effective and durable coating of the component after hybridization ( FIG. 8 c ), while preventing the incipient cracking that is frequently observed on components obtained by conventional “flip chip” hybridization and coating. The coating resin may be of the same type as the underfill resin, and for example, epoxy, silicones, acrylates etc.
The inventive method therefore also offers the possibility of easy localization by treating, using either mechanical masks or optical masks, areas of strong surface energy. This action means that droplets of various chemical species, from relatively non viscous liquids (water, biological molecules, oil) to viscous liquids (gum, resin, paint) can be localized on a pattern determined by the mask, and on the other hand, the adhesion of living cells (and the adsorption of biological molecules) can be localized in the areas.
According to an alternative of the invention shown in FIG. 4 , the area of non-wettability 10 is modified by defining an additional surface 11 , in the case in point opposite to the surface 9 , and intended to collect any excess coating resin.
The method may be advantageously implemented in respect to particular components and in particular to prevent the deposition or migration of the coating resin under the chip 2 , and generally speaking under the active component.
An optoelectronic component has thus been shown in relation to FIGS. 5 and 6 , wherein a laser 13 is hybridized on a substrate 3 . The latter is bored with a through orifice 14 , intended to let the laser beam through or to receive an optical fibre 15 . Quite clearly, in the context of a VCSEL of this kind, the area of the chip located in line with the orifice 14 must be free from coating resin. To this end, on the periphery of the through orifice 14 is deposited a ring 16 of a material of non-wettability in regards to the coating resin.
Another particular component implementing the coating method has also been shown in relation to FIG. 7 . In this case, it is required that the adhesive securing the linear lens array 17 to a transparent substrate 18 must not disturb the optical function of the lenses 17 and must not affect the optical path of the laser beams coming from a linear laser array 19 , hybridized on the opposite face of the transparent substrate 18 . To prevent the adhesive from migrating and spreading over the optical paths, an anti-wetting covering is deposited, for example in the form of a peripheral seam as in the previously described example.
The full advantage of the invention can now be seen, in simplifying the means employed in coating the component hybridization area in order to guarantee the mechanical strength thereof. | The method of coating the area of hybridization of a component that is constituted by two elements bonded to one another by means of a soldering material, including depositing proximate to the component a coating substance capable of filling by capillarity action the volume defined between the hybridized elements of the component. Further, along the periphery of the hybridization area on the lower element of the component is an area of non-wettability in regards to the coating substance, that is defined by depositing an anti-wetting covering of PECVD in regards to the coating substance, whereby the anti-wetting covering on the first element encompasses the hybridization area and surrounds a wetting surface for the coating substance. | 7 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application is a Divisional of and claims the benefit of priority to U.S. patent application Ser. No. 12/968,592 filed on Dec. 15, 2010, now U.S. Pat. No. 8,217,519, which claims the benefit of priority and is a Divisional of U.S. patent application Ser. No. 12/032,430 filed on Feb. 15, 2008, now U.S. Pat. No. 7,888,806, which claims the priority of Korean Patent Application No. 2007-0073476, filed on Jul. 23, 2007, in the Korean Intellectual Property Office, the disclosure of each of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to multichip modules and more particularly to the manner in which electrical connections are made to the module or between chips in the module.
2. Description of the Related Art
As electronic products move to smaller size and higher density and performance, semiconductors have correspondingly become smaller with their components and connections becoming denser. This in turn has lead to the development of multichip package (MCPs) in which a plurality of semiconductor chips are stacked on a substrate such as a printed circuit board. This creates a high density, high performance package that is nonetheless small in size.
As density increases and size decreases, however, problems may develop with multichip modules. For example, in FIG. 1 , an MCP includes a first semiconductor chip 10 mounted on a substrate 12 . A second semiconductor chip 14 is mounted on semiconductor chip 10 thereby forming an MCP comprising semiconductor chips 10 , 14 . Chip 10 , which is larger than chip 14 , includes terminals such as terminals 16 , 18 . Chip 14 also includes terminals, like terminals 20 , 22 . As can be seen, the terminals on chip 14 are spaced much more closely together than those on chip 10 . The terminals on both chips are electrically connected to conductive pads, like pads 24 , 26 , formed on substrate 12 via wire bonds, such as wire bonds 28 , 30 .
The terminals on chip 14 , like terminals 20 , 22 , are further away and higher from substrate 12 than the terminals, like terminals 16 , 18 , on chip 10 . As a result, the wire bonds connecting the terminals on chip 14 to substrate 12 are longer and form a greater angle relative to the substrate than the wire bonds that connect the terminals on chip 10 to the substrate pads. And the terminals on chip 14 are much closer together. All these factors may combine to produce wire sweeping, in which the wire bonds connecting the terminals on chip 14 to the substrate pads electrically short against one another. Also, the longer each wire bond, the more likely the wire will be broken during manufacturing, e.g., when the wires are encapsulated.
In addition to these problems, when the terminals are close together as on chip 14 , there is a limit to how many adjacent terminals can be wire bonded to the substrate. As seen in FIG. 1 , there is a gap indicated generally at 31 that must be included because the density and length of the bonds limit the number of adjacent wire bond connections.
It would be desirable to provide wire bonds or other electrical connections on the upper chip of an MCP that are shorter and have a smaller bonding angle relative to the substrate. One approach uses a redistribution network, but it cannot be employed in some types of chips because the chip design must include certain electrical characteristics, and this complicates chip design.
Another approach uses an interposer, but this increases fabrication cost and does not completely resolve the problems associated with long wires, terminals at a high elevation relative to the substrate, and large bonding angles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged partial view of a prior art MCP.
FIG. 2 is a top plan view of a semiconductor chip constructed in accordance with the present invention.
FIG. 3 is an enlarged cross sectional view taken along line 3 - 3 in FIG. 2 .
FIG. 4 is a second embodiment of the present invention depicted in a view similar to FIG. 3 .
FIG. 5 is a top plan view of a third embodiment of the present invention.
FIG. 6 is a top plan view of a fourth embodiment of the present invention.
FIG. 7 is a fifth embodiment of the present invention depicted in a view similar to FIGS. 3 and 4 .
FIG. 8 is a top plan view of a sixth embodiment of the present invention.
FIG. 9 is a perspective, somewhat schematic view of a first MCP constructed in accordance with the present invention.
FIG. 10 is a perspective, somewhat schematic view of a second MCP constructed in accordance with the present invention.
FIG. 11 is a perspective, somewhat schematic view of a third MCP constructed in accordance with the present invention.
FIG. 12 is a perspective, somewhat schematic view of a fourth MCP constructed in accordance with the present invention.
FIG. 13 is a perspective, somewhat schematic view of a fifth MCP constructed in accordance with the present invention.
FIG. 14 is a cross sectional view of the fifth embodiment of the present invention.
FIG. 15 is a perspective, somewhat schematic view of a sixth MCP constructed in accordance with the present invention.
FIG. 16 is a cross sectional view of the sixth embodiment of the present invention.
FIG. 17 is a perspective, somewhat schematic view of a seventh MCP constructed in accordance with the present invention.
FIG. 18 is a top, plan, somewhat schematic view of a eighth MCP constructed in accordance with the present invention.
FIG. 19 is a schematic diagram of a card constructed in accordance with the present invention.
FIG. 20 is a schematic diagram of a system constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Turning again to the drawings, FIGS. 2-8 illustrate a variety of semiconductor chips that may be placed on top of another chip in an MCP. FIGS. 9-18 illustrate semiconductor chips, including chips like those depicted in FIGS. 2-8 , in MCPs.
With reference first to FIGS. 2 and 3 , indicated generally at 32 is a semiconductor device. Device 32 includes a plurality of conductive lines, like conductive lines 34 , 36 . The conductive lines are formed on the surface 38 of a dielectric layer 40 , which in turn is formed on a semiconductor substrate 42 . The conductive lines can form a pattern of alternating lines and spaces, as shown. An internal circuit region 44 is formed in dielectric layer 40 . Conductive chip pads, like pads 46 , 48 , are formed on dielectric layer 40 and connect to internal circuit portions (not depicted) of semiconductor device 32 . A passivation layer 50 is formed on dielectric layer 40 .
Openings, like openings 52 , 54 , are formed in passivation layer 50 with opening 52 exposing a portion of chip pad 46 and opening 54 exposing a portion of conductive line 34 . Each of the chip pads, like chip pads 46 , 48 , include a corresponding opening to expose the chip pads for connection to external circuitry. Additional openings, like opening 54 , are formed over at least some of the metal lines in a manner that will be described more fully herein.
The chip pads, like chip pads 46 , 48 , may be formed in the same process step, or in a different step, as formation of the conductive lines, like lines 34 , 36 . The conductive lines are electrically isolated from the chip pads. Conductive lines that provide power or ground connections in an MCP may be wider than other conductive lines.
In FIG. 4 , indicated generally at 56 is another semiconductor chip according to the invention. Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. In chip 56 , the conductive lines, like conductive lines 34 , 36 , are formed on top of passivation layer 50 rather than on top of dielectric layer 40 as in FIG. 3 . A resin layer 58 is formed on top of passivation layer 50 and includes openings, like openings 60 , 62 , to expose the chip pads and parts of the conductive lines in the same manner as openings 52 , 54 in FIG. 3 . Resin layer 58 comprises a polymer layer including polyimide.
In chip 56 , the chip pads and conductive lines can be formed in different planes and in different process steps. To increase wire bonding efficiency and to prevent difficulties during wire bonding caused by the difference in height between the chip pads and the conductive lines, the height of the chip pads, like chip pad 46 , may be extended in a further process step to the level of dashed line 64 thereby bringing the upper surfaces of both the conductive lines and the chip pads to substantially the same plane.
The extension of the chip pads, like chip pad 46 , to the level of dashed line 64 may be accomplished in the same process step in which the conductive lines are formed thereby bringing the upper surfaces of both the conductive lines and the chip pads to substantially the same plane. For example, after the formation of the opening 52 as shown in FIG. 3 , a blanket conductive layer (not shown) can be formed on passivation layer 50 and chip pad 46 . The conductive lines and an extended portion (not shown) of chip pad 46 can be formed by a conventional patterning process of the blanket conductive layer. The resin layer 58 is formed on top of passivation layer 50 and includes the openings, like opening 62 and upper portion of opening 60 , to expose the extended portion of the chip pads and parts of the conductive lines in the same manner as openings 52 , 54 in FIG. 3 .
In FIG. 5 , indicated generally at 66 is another semiconductor chip according to the invention. Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. In chip 66 , the conductive lines, like conductive lines 34 , 36 , are at an angle relative to the generally rectangular shape of chip 66 . Lines 34 , 36 may be placed at any angle, and may not even necessarily be linear—for example, one or more lines could be curved—so long as the lines are electrically isolated from the chip pads, like pads 46 , 48 .
In FIG. 6 , indicated generally at 68 is another semiconductor chip according to the invention. Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. In chip 68 , the conductive lines, like conductive lines 34 , 36 , are separated into two groups 70 , 72 , with the groups being separated by a space indicated generally at 74 . As a result, lines 34 , 36 are electrically isolated from collinear lines 76 , 78 , respectively. As will be seen, this permits lines in each group, like lines 34 , 36 , to propagate different signals because they are electrically isolated from one another.
In FIG. 7 , indicated generally at 80 is another semiconductor chip according to the invention. Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. In chip 80 , at least one of conductive lines, like 82 , and chip pad 46 are each connected to a conductive through-silicon via (TSV) 83 , 84 , respectively, as are several other of the conductive lines and chip pads, although the chip pad connections are not visible in FIG. 7 . Each conductive TSV is connected to a conductive pad, like pads 86 , 88 .
The TSVs are each formed through dielectric layer 40 and semiconductor substrate 42 and thereby carry signals from the metal lines and chip pads to the conductive pads, like pads 86 , 88 , on the underside of semiconductor chip 80 . As will be seen, this arrangement facilitates connections in an MCP. This approach could also be used in the embodiment of FIG. 4 .
In FIG. 8 , indicated generally at 90 is another semiconductor chip according to the invention. Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Semiconductor chip 90 has conductive lines laid out in a manner similar to semiconductor chip 68 in FIG. 6 . Chip 90 , however, includes center chip pads, like chip pads 92 , 94 . As the chip pads in the other embodiments do, the chip pads in chip 90 make electrical connections with circuitry internal to chip 90 . Unlike the other embodiments, however, each of the chip pads on chip 90 are electrically connected to a single corresponding conductive line, like chip pads 92 , 94 are connected to lines 76 , 34 , respectively. As can be seen, there are additional conductive lines that are not connected to chip pads. These additional unconnected lines are electrically isolated from the internal chip circuitry and from the chip pads. This arrangement provides for redistribution of the signals on the chip pads via the conductive line to which each pad is connected, as will be further described in connection with FIG. 18 .
Indicated generally at 96 in FIG. 9 is an MCP. The MCP includes a first semiconductor chip 98 and a second semiconductor chip 100 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 98 is constructed similarly to chip 32 in FIGS. 2 and 3 . Chip 100 is mounted on chip 98 via adhesive, and chip 98 is mounted on a substrate 102 , also using adhesive. A first side (not visible) of chip 98 is mounted on substrate 102 . Chip 100 is mounted on the second side 99 of chip 98 .
Chip 100 includes conductive pads as shown that are connected via wire bonds, like wire bond 104 , to conductive line 34 . A portion of conductive line 34 is exposed by an opening 106 etched into passivation layer 50 in the manner shown in FIG. 3 . This permits wire bond 104 to be electrically connected to the conductive line by a bonding process. As a result, internal circuitry of chip 100 is electrically connected to conductive line 34 via a chip pad on chip 100 and wire bond 104 . This redistributes the connection point for the internal circuitry of chip 100 .
Another opening 108 over conductive line 34 provides access to the conductive line for bonding one end of another wire 110 to conductive line 34 . The other end of wire 110 is bonded to a terminal 112 on substrate 102 . Other terminals on chip 100 are bonded to other conductive lines via wire bonds, like wire bond 104 , as shown, and these other conductive lines are in turn bonded to terminals, like terminal 112 on substrate 102 , via wire bonds like wire bond 110 . In this manner, the connections to circuitry in chip 100 are redistributed to facilitate wire bonding in a manner that obviates problems associated with the length, height, and bonding angles of the conventional approach. Chip pads, or terminals, on first semiconductor chip 98 are connected to terminals, like terminal 114 on substrate 102 , via wire bonds like wire bond 225 . The terminals such as terminal 114 are also referred to herein as electrical contacts.
This approach provides for electrically connecting chip 100 and substrate 102 with wire bonds that have a length, height, and bonding angle similar to the wire bonds that connect the pads on chip 98 to the substrate.
Indicated generally at 118 in FIG. 10 is an MCP. The MCP includes a first semiconductor chip 120 , a second semiconductor chip 122 , and a third semiconductor chip 124 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 120 is constructed similarly to chip 98 in FIG. 9 . And chips 122 , 124 are mounted on chip 120 similarly to the way chip 100 is mounted on chip 98 in FIG. 9 .
Chip 124 includes pads that are connected to metal lines in a manner similar to how the pads on chip 122 are connected to metal lines. For example, on chip 122 a wire bond 104 connects one of the pads on chip 122 to a conductive line 128 . Another wire bond 130 is connected to conductive line 128 through an etched opening 132 . The other end of wire bond 130 is connected to one of the terminals on substrate 102 .
Because each conductive line is isolated from every other conductive line, and from internal semiconductor circuitry, adjacent conductive lines, like lines 34 , 128 , may be used to route connections from the pads on chips 122 , 124 , respectively. In MCP 118 , every other conductive line is associated with connections from one of chips 122 , 124 . In other words, if the conductive lines are consecutively numbered, the odd ones are connected to pads on one of the chips and the even ones are connected to pads on the other chip.
Indicated generally at 134 in FIG. 11 is an MCP. The MCP includes a first semiconductor chip 136 and a second semiconductor chip 138 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 136 is constructed similarly to chip 68 in FIG. 6 . And chip 138 is mounted on chip 136 similarly to the way chip 100 is mounted on chip 98 in FIG. 9 .
As can be seen, pads on one side of chip 138 are connected via wire bonds as previously described to adjacent lines in line group 70 , and the pads on the other side are connected via wire bonds to adjacent lines in line group 72 . Each of the lines to which a pad on chip 138 is connected is in turn connected via another wire bond to a terminal on substrate 102 . As a result, the pitch of the pads or, the number of pads along the edges of the second chip, may be increased because at least two sides of chip 136 may be used as signal paths via the metal line groups 70 , 72 .
Indicated generally at 140 in FIG. 12 is an MCP. The MCP includes a first semiconductor chip 142 , a second semiconductor chip 144 , and a third semiconductor chip 146 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 142 is constructed similarly to chip 136 in FIG. 11 . And chips 144 and 146 are mounted on chip 142 similarly to the way previously described chips are mounted on the first semiconductor chip.
In MCP 140 the pads on chip 144 are connected via wire bonds to conductive lines in group 70 in the manner previously described, and the pads on chip 146 are connected to the conductive lines in group 72 . The two groups of conductive lines are in turn connected via wire bonds to terminals on substrate 102 , also as previously described. This approach provides for a high density MCP.
Indicated generally at 148 in FIG. 13 is an MCP. The MCP includes a first semiconductor chip 150 and a second semiconductor chip 152 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 150 is constructed similarly to chip 98 in FIG. 9 . Chip 152 is mounted on chip 150 using solder bumps 154 , 156 , best seen in FIG. 14 . Solder bump 154 is mounted on a chip pad 158 that is connected to internal circuitry of chip 152 . But bump 156 provides only structural support for chip 152 ; it is not connected to any internal chip circuitry. Both bumps 154 , 156 are supported on metal line 34 , which carries whatever voltage appears on pad 158 . The pitch of the bumps on chip 152 is substantially the same as the pitch of the conductive lines, like conductive line 34 , on chip 150 . This approach facilitates use of flip chip bonding with the bumps being formed on chip 152 . As a result, there are no wire bonds connected to the second chip, thus eliminating disadvantages associated with use of wire bonds.
In an alternative approach (not shown) conducting bump 154 may be received completely within the opening in the passivation layer over conductive line 34 with the underside of chip 152 being supported on passivation layer 50 . This may require a thicker passivation layer than depicted in FIG. 14 , but eliminates the need for a support bump, like bump 156 , because the chip is resting on and supported by passivation layer 50 .
In another alternative approach, the first semiconductor chip 150 can be mounted on the substrate 102 with its active surface, which includes chip pads, facing substrate 102 . In that structure, an insulating layer (not shown) can be formed on the surface opposite the active surface of the first semiconductor chip 150 , namely the exposed surface of the semiconductor substrate 42 . The conductive lines can be formed on the insulating layer (not shown). The first semiconductor chip 150 can be coupled to substrate 102 by flip chip bonding and the conductive lines can be used to form electrical connections between the second semiconductor chip 152 and the substrate 102 . The second semiconductor chip may be connected to the conductive lines in any manner described herein.
Indicated generally at 159 in FIGS. 15 and 16 is an MCP. The MCP includes a first semiconductor chip 160 mounted on the substrate 102 with an adhesive layer 163 and a second semiconductor chip 162 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Both chips are constructed similarly to chip 80 in FIG. 7 in that each has conductive TSVs, like TSV 166 in chip 160 and TSV 164 in chip 162 .
One end of TSV 164 is connected to a conductive pad 168 formed on chip 162 . Pad 168 is connected to internal circuitry of chip 162 . The other end of TSV 164 is connected to a redistributed pad 170 , which is in turn mounted on conductive line 34 . Alternatively, TSV 164 may be directly connected to conductive line 34 without the need for redistributed pad 170 .
The upper end of a TSV 166 (in chip 160 ) is connected to the underside of conductive line 34 with the lower end being connected to a terminal 172 formed on substrate 102 . As a result, an internal circuit connection in chip 162 is redistributed via pad 168 , TSV 164 , conductive line 34 , and TSV 166 to terminal 172 on substrate 102 . This approach obviates the need for any wire bonding. In other words, it provides an MCP without any wire bonds. The first semiconductor chip 160 is secured to substrate 102 with an adhesive layer 163 .
Indicated generally at 174 in FIG. 17 is an MCP. The MCP includes a first semiconductor chip 176 , a second semiconductor chip 178 , and a third semiconductor chip 180 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chips 176 , 178 are constructed similarly to chip 98 in FIG. 9 . Chips 176 , 178 are substantially identical to one another and may comprise, e.g., memory chips. As can be seen, chip 178 is mounted on chip 176 with the centers of both chips offset from one another. This results in two sides of chip 178 lapping over two edges of chip 176 with substantial portions of the other two sides 182 , 184 of chip 178 being set back from the other two edges of chip 176 . As a result, wire bond connections, like wire bond 110 , may be made between the conductive lines on chip 176 and the terminals on substrate 102 , like terminal 112 , and further wire bond connections, like wire bond 186 , may be made between the conductive lines on chip 178 and the conductive lines on chip 176 . It is of course possible to stack chips of different sizes with the larger chip preferably being beneath a smaller chip.
Chip 180 , which may be, e.g., an LSI circuit such as a processor, is mounted on chip 178 using adhesive. The pads on chip 180 are connected to conductive lines on chip 178 using wire bonds, like wire bond 188 . As a result, circuitry internal to chip 180 may be connected via wire bonds, like wire bond 188 , to the conductive lines on chip 178 . These conductive lines are connected via wire bonds, like wire bond 186 , to conductive lines on chip 176 , which are in turn connected via wire bonds, like wire bond 110 , to terminals, like terminal 112 on substrate 102 .
The terminals on chips 176 , 178 are connected via wire bonds, like wire bonds 190 , 192 , respectively, to terminals on substrate 102 . In an alternative embodiment (not shown) TSVs, like those shown in FIGS. 7 , 15 , and 16 , may be used to provide some or even all of the connections shown as wire bonds in FIG. 17 .
Indicated generally at 194 in FIG. 18 is an MCP. The MCP includes a first semiconductor chip 196 and a second semiconductor chip 198 . Structure that corresponds to previously identified structure is either unnumbered or carries the same identifying number. Chip 196 is constructed similarly to chip 90 in FIG. 8 . Chip 196 includes a plurality of conductive chip pads, like pads 92 , 94 disposed on an upper surface of chip 196 beneath chip 198 . These pads on chip 196 are disposed in two substantially parallel rows beneath chip 198 with pad 92 being in one row and pad 94 in the other.
Every other conductive line in each of groups 70 , 72 is connected to one of the pads, like pads 92 , 94 . Every other conductive line in each of groups 70 , 72 is connected to a conductive pad, like pads 206 , 208 , on the upper surface of chip 198 via wire bonds, like wire bonds, 230 a , 230 b , respectively. Put differently, every even conductive line is connected to pads, like pads 92 , 94 , on the upper surface of chip 196 , and every odd conductive line is connected to pads, like pads 206 , 208 , on the upper surface of chip 198 , with the latter connections being made with wire bonds, like wire bonds 230 a , 230 b.
Further wire bonds, like wire bonds 225 , 220 , connect the conductive lines to terminals, like terminals 218 , 210 , respectively, on substrate 102 . In an alternative embodiment (not shown), a chip smaller than chip 198 is mounted on chip 196 between the two rows of pads on chip 196 . In other words, the second chip does not cover the pads on the first chip.
Turning now to FIG. 19 , indicated generally at 222 is a schematic diagram of a card constructed in accordance with the present invention. Card 222 may be, e.g., a multimedia card (MMC) or a secure digital card (SD). Card 222 includes a controller 224 and a memory 226 , which could be a flash, PRAM, or another type of non-volatile memory. A communication channel, indicated generally at 228 , permits the controller to provide commands to the memory and to transfer data into and out of memory 226 . Controller 224 and memory 226 may comprise an MCP in accordance with any of the previously described embodiments. The card 222 can have a larger density than conventional type. In the present invention, it is possible to remove interposer chips, so that card thickness can be reduced with respect to the conventional card having interposer chips. Additionally, the present invention can reduce defects from card caused by wire broken, so that reliability of card can be increased.
Considering now FIG. 20 , indicated generally at 230 is a system constructed in accordance with the present invention. System 230 may be, e.g., a computer system, a mobile phone, an MP3 player, a GPS navigation device, a solid state disk (SSD), a household appliance, etc. System 230 includes a processor 232 ; a memory 234 , which could be a DRAM, flash, PRAM, or another type of memory; and an Input/Output Device 236 . A communication channel 238 permits the processor to provide commands to the memory to transfer data into and out of memory 234 via channel 238 . Data and commands may be transferred to and from system 230 via Input/Output device 236 . Processor 232 and memory 234 may comprise an MCP in accordance with any of the previously described embodiments. The present invention can make the stable system because the present invention can reduce defects caused by a broken wire. | A semiconductor chip is provided. The semiconductor chip includes a semiconductor substrate, a circuit on the substrate, an insulating layer formed on the circuit, and a plurality of electrically floating conductor lines formed on the insulating layer, at a major surface of the semiconductor chip. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to supports and templates for masonry construction, and more particularly to an arch support system for masonry construction to support brickwork against a curved surface as the bricks are laid.
2. Brief Description of the Prior Art
It is very difficult and time consuming to install brickwork to concave arcuate, domed, or curved surfaces such as the interior of tunnels, vessels and kilns, etc., particularly when the bricks must be laid and supported in an arcuate overhead position and in adjacent rows or rings extending for great distances.
Dominquez, U.S. Pat. No. 4,702,044 discloses an adjustable arch support for the laying of brickwork which incorporates a central hub having a plurality of radially extending telescopic struts pivotally connected at their inner ends to the central hub and pivotally connected at their outer ends to a flexible band. The band incorporates at least one lockable hinge allowing the band to be set either to an even curve or to a discontinuous curve having a peak at the hinge. The shape of the arch is determined by adjustment of the struts which bends the band to the desired configuration.
The present invention is distinguished over the prior art in general, and this patent in particular by an apparatus and method for supporting brickwork against a curved surface during masonry construction wherein a first hub is positioned at the center of a curved surface to be lined with bricks. A second hub is positioned adjacent the first and has an outer wall extending beyond the width of the first hub in radially spaced relation with a series of circumferentially spaced slots therein. Mortared bricks are placed sequentially against the curved surface and supported by telescopic spring-loaded brick support struts placed on the second hub to extend generally radially outward therefrom and engage each mortared brick to form a ring of bricks each pressed against the curved surface by a brick support strut. Telescopic spring-loaded rib support struts are sequentially placed on the first hub to extend radially outward through the slots of the second hub and engage the approximate center of certain circumferentially spaced bricks of the ring of bricks. Each rib support strut is sequentially contracted and an elongate resilient rib is installed between the outer end of the rib support struts and the inner diameter of the ring of bricks such that the rib member and rib support struts exert a radial outward force thereon. A coupling is connected to the rib support struts and a second ring of bricks are installed adjacent the first ring and supported by brick support struts while a second rib is installed in the couplings. Subsequent rings of bricks are installed by removing the brick support struts, installing another first hub and repositioning the second hub adjacent thereto and repeating the process.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an arch support system for masonry construction to support bricks against a curved surface as the bricks are being laid.
It is another object of this invention to provide an arch support system for masonry construction which allows brickwork to be easily and quickly installed on concave arcuate, domed, or curved surfaces such as the interior of tunnels, vessels, and kilns.
Another object of this invention is to provide an arch support system for masonry construction which allows brickwork to be easily and quickly installed and supported in an arcuate overhead position and in adjacent rows or rings extending for great distances.
Another object of this invention is to provide an arch support system for masonry construction in portable modular form which is easily and quickly erected and taken down.
Another object of this invention is to provide an arch support system for masonry construction in modular form which is easily and quickly adjusted to fit a variety of sizes of curved surfaces.
A further object of this invention is to provide an arch support system for masonry construction wherein the components are quickly erected and reused sequentially to allow continuous installation of brickwork with no down-time while the mortar sets.
A still further object of this invention is to provide an arch support system for masonry construction which is simple in construction, and economical to manufacture.
Other objects of the invention will become apparent from time to time throughout the specification and claims as hereinafter related.
The above noted objects and other objects of the invention are accomplished by an apparatus and method for supporting brickwork against a curved surface during masonry construction wherein a first hub is positioned at the center of a curved surface to be lined with bricks. A second hub is positioned adjacent the first and has an outer wall extending beyond the width of the first hub in radially spaced relation with a series of circumferentially spaced slots therein. Mortared bricks are placed sequentially against the curved surface and supported by telescopic spring-loaded brick support struts placed on the second hub to extend generally radially outward therefrom and engage each mortared brick to form a ring of bricks each pressed against the curved surface by a brick support strut. Telescopic spring-loaded rib support struts are sequentially placed on the first hub to extend radially outward through the slots of the second hub and engage the approximate center of certain circumferentially spaced bricks of the ring of bricks. Each rib support strut is sequentially contracted and an elongate resilient rib is installed between the outer end of the rib support struts and the inner diameter of the ring of bricks such that the rib member and rib support struts exert a radial outward force thereon. A coupling is connected to the rib support struts and a second ring of bricks are installed adjacent the first ring and supported by brick support struts while a second rib is installed in the couplings. Subsequent rings of bricks are installed by removing the brick support struts, installing another first hub and repositioning the second hub adjacent thereto and repeating the process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded isometric view of the major components of the arch support apparatus for masonry construction in accordance with the present invention.
FIG. 2 is a longitudinal cross section through a rib support strut component of the arch support apparatus.
FIG. 3 is a longitudinal cross section through a brick support strut component of the arch support apparatus.
FIG. 4 is an isometric view of the arch support apparatus showing the beginning operation in installing a brick lining on a curved surface.
FIG. 5 is a side elevation showing the carriage moved adjacent to the rib support hub such that the outwardly extended portion of the flat members extend beyond the width of the rib support hub and are aligned in the same vertical plane as the outer end of the first ring of bricks to be laid.
FIG. 6 is an elevation view showing a ring of bricks pressed against the curved surface by the brick support struts.
FIG. 7 is an isometric view showing the beginning operation in placing the rib support struts on the previously installed ring of bricks.
FIG. 8 is an elevation view showing the rib support struts positioned against certain circumferentially spaced bricks of the previously installed ring of bricks.
FIG. 9 is an elevation view showing an elongate resilient rib installed and biased against the previously installed ring of bricks by the rib support struts.
FIG. 10 is an isometric view showing the beginning operation in installing a subsequent ring of bricks adjacent a previously installed ring that is held against the curved surface by a rib and rib support struts, and joining a coupling to the previously installed rib support struts.
FIG. 11 is a side elevation view showing the installation of a second series of brick support struts after the rib has been installed and biased against the previously installed ring of bricks by the rib support struts.
FIG. 12 is a side elevation view showing the installation of a third and fourth ring of bricks adjacent the first and second rings of bricks.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings by numerals of reference, there is shown in FIG. 1, an exploded isometric view of the major components of a preferred arch support system 10 for masonry construction to support brickwork against a curved surface as the bricks are laid.
A base track assembly 11 having a pair of opposed L-shaped angle members 12 secured in parallel laterally spaced relation by transverse crossmembers 13 forms a pair of guide rails 14. A length of square tubing 15 secured to the crossmembers 13 extends longitudinally between the guide rails 14 along a center longitudinal axis. Similar track assembly extension members 16 formed of square tubing 15 and angle members 12 may be joined to either end of the base track assembly 11 to extend it in the longitudinal direction.
A semicircular rib support hub 17 is secured to the top end of a tubular telescopic vertical support leg 22. The rib support hub 17 has a flat bottom 18, opposed ends 19, and an arcuate curved top wall 20. A series of circumferentially spaced holes 21 extend a short distance inwardly from the arcuate top wall 20 of the rib support hub 17. The circumferential spacing of the holes 21 in the arcuate top wall of the rib support hub 17 correspond in direct relation to predetermined chord points (for example 14" or 16") on a semicircular ring of bricks to be installed on a concentrically spaced curved surface (described hereinafter).
The tubular telescopic vertical support leg 22 is formed of a lower tubular member 23 slidably received in the bottom end of an upper tubular member 24. The rib support hub 17 is secured to the top end of the upper tubular member 24. A lock screw 25 installed through the side wall of the upper tubular member 24 near its bottom end grips the lower tubular member 23 to adjust the vertical length of the support leg 22. A square C-shaped clamp 26 having a lock screw 27 is secured to the bottom end of the lower tubular member 23. The clamp 26 removably clamps the vertical support leg 22 to the central length of square tubing 15 of the base track assembly 11. Several rib support hub assemblies are provided, depending upon the particular job requirements.
A series of tubular telescopic spring-loaded longitudinally adjustable rib support struts 28 are used with the rib support hub 17. Referring additionally to FIG. 2, each rib support strut 28 has an intermediate tubular member 29 with a lower tubular member 30 slidably received in its bottom end and an upper tubular member 31 slidably received in its top end. The lower tubular member 30 is enclosed at its bottom end and a short pin 32 extends from the enclosed bottom end. A longitudinal slot 33 extends through the side wall of the lower tubular member 30 intermediate its top and bottom ends. The shank 34 of a lock screw 35 installed through the side wall of the intermediate tubular member 29 near its bottom end is received in the slot 33 to prevent complete removal of the lower tubular member 30, while allowing axial travel relative to the intermediate tubular member 29. A compression spring 36 is installed inside the intermediate tubular member 29 and engaged with the top and bottom ends, respectively, of the lower and upper tubular members 30 and 31. A lock screw 37 is installed through the side wall of the intermediate tubular member 29 near its top end to grip the upper tubular member 31. The pins 32 at the bottom end of the rib support struts 28 are received in the holes 21 in the arcuate top wall 20 of the rib support hub 17, and the rib support struts extend radially outward from the rib support hub.
A short length of square tubing 38 is secured to the outer end of each upper tubular member 31. A pair of lock screws 39 extend through the bottom wall of the short length of square tubing 38 near each outer end. A U-shaped channel element 40 is secured to the top wall of each short length of square tubing 38.
Referring again to FIG. 1, a series of square tubing coupling members 41 are provided which have a lock screw 42 that extends through their bottom wall at one end, a tubular extension 43 extending from the opposite end, and a U-shaped channel element 44 secured to their top wall. The tubular extension 43 is received in the open end of the short length of square tubing 38 at the outer ends of each rib support strut 28 and extends perpendicular to the rib support strut. A series of square tubing spacer extensions 45 are also provided. The ends of the spacer extensions 45 are sized to fit inside the coupling members 41 and short length of square 38 at the outer ends of the rib support struts 28.
A series of elongate tubular rib members 46 formed of resilient material, such as PVC tubing are provided. The rib members 46 are received and supported in the channel elements 40 and 44 on the short length of square tubing 38 of the rib support struts 28 and coupling members 41, respectively, as described hereinafter.
A carriage 47 having a flat top plate 48 with four wheels 49 near each corner rides in the L-shaped angle members 12 of the track assembly 11. The lower tubular member 50 of a tubular telescopic vertical support leg 51 is secured at its bottom end to the center of the top plate 48 of the carriage 47 and its top end is slidably received in the bottom end of an upper tubular member 52. A lock screw 53 installed through the side wall of the upper tubular member 52 near its bottom end grips the lower tubular member 50 to adjust the vertical length of the support leg 51.
A semicircular brick support hub 54 is secured to the top end of the upper tubular member 52 of the vertical support leg 51. The brick support hub 54 has a flat bottom wall 55, opposed end walls 56, and an arcuate curved top wall 57. A series of spaced apart flat members 58 are secured to the top wall 57 of the hub 54 and extend outwardly beyond one end wall to define circumferentially spaced transverse openings or slots 59 therebetween. The length of the flat members 58 are approximately the same length as two bricks placed end to end with a mortar joint therebetween. The circumferential spacing of the slots 59 in the arcuate top wall of the brick support hub 54 correspond to the spacing of the holes 21 in the rib support hub 17. In other words, the centers of the slots 59 correspond to predetermined chord points (for example 14" or 16") on a semicircular ring of bricks to be installed on the concentrically spaced curved surface (described hereinafter). The width of each slot 59 is sufficient to allow the rib support struts 28 to extend radially therethrough between adjacent flat members 58.
Telescoping lateral span arms 60 extend laterally outward from the bottom of the brick support hub 54 on opposite sides. The lateral span arms 60 are formed of a center member 61 of square tubing with one end of inner members 62 of square tubing slidably received in the opposite ends of the center member. A square tubing member 63 is secured at its center to the outer end of each inner tubular member 62 perpendicular thereto. A pair of lock screws 64 extend through the side wall of the center member 61 near each outer end.
A series of tubular telescopic spring-loaded longitudinally adjustable "pogo sticks" or brick support struts 65 are used with the brick support hub 54. Referring additionally to FIG. 3, each brick support strut 65 has a tubular collar 66 with the bottom end of an upper tubular member 67 received in its top end and a rounded resilient end cap 68 is secured on the top end of the upper tubular member. The top end of an intermediate tubular member 69 is received in the bottom end of the collar 66. Lock screws 70 installed through the side wall of the collar 66 near its top and bottom ends secure the upper and intermediate tubular members 67 and 69 to the collar. The top end of the intermediate tubular member 69 is enclosed by a wall 71. The collar 66 allows interchangeable upper and intermediate tubular members 67 and 69 of various lengths to be assembled to adjust the length of the brick support struts 65 to fit the particular job requirements.
The upper portion of a lower tubular member 72 is slidably received in the lower end of the intermediate tubular member 69. A compression spring 73 is disposed inside the intermediate tubular member 69 with one end engaged on the wall 71 and its opposite end engaged on the top end of the lower tubular member 72 to normally urge them apart. The bottom end of the lower tubular member 72 is enclosed and a short pin 74 extends downwardly from the enclosed bottom end. A longitudinal slot 75 extends through the side wall of the lower tubular member 72 intermediate its top and bottom ends. The shank 76 of a lock screw 77 installed through the side wall of the intermediate tubular member 69 near its lower end is received in the slot 75 to prevent complete removal of the lower tubular member 72, while allowing axial travel relative to the intermediate tubular member 69. The pin end 74 of the brick support struts 65 are received on the flat members 58 of the brick support hub 54 and the brick support struts extend generally radially outward from the brick support hub as described hereinafter.
OPERATION
Having described the major components of the preferred arch support system, the following is a description of its operation in installing a brick lining on a curved surface, utilizing, as an example, a long tunnel having an arcuate ceiling hereinafter referred to as the arch.
Referring to FIGS. 4 and 5, measurements are taken of the curved surface S to be lined to determine overall dimensions of the arch and the span or diameter D of the arch in a horizontal plane, and the center C of the horizontal diameter is calculated. The track assembly 11 is placed on the floor of the tunnel with its center longitudinal axis along a line corresponding to the center C of the horizontal diameter D. If the floor of the tunnel is not flat or level, or if the distance between the top of the arch and the floor is excessive, a suitable scaffold may be erected to create a flat level surface for the track.
The C-shaped clamp 26 at the bottom end of the telescopic vertical support leg 22 of the rib support hub 17 is clamped on the central length of square tubing 15 of the track assembly 11 and the length of the vertical support leg 22 is adjusted to align the rib support hub 17 at the center C of the horizontal diameter of the arch and thereafter locked at the proper length by the lock screw 25. The rib support hub 17 is positioned such that the holes 21 in its arcuate wall 58 will be aligned with the center of the first ring of bricks to be installed. A rib support strut 28 is placed in the top center hole 21 of the rib support hub 17 to extend vertically between the rib support hub and the curved surface S and allowed to extend axially under the force of its compression spring to maintain the hub in the proper position.
The carriage 47 is placed in the track assembly 11, and the length of the vertical support leg 51 is adjusted to place the brick support hub 54 at the center C of the horizontal diameter of the arch and thereafter locked at the proper length by the lock screw 53. As shown somewhat schematically in FIG. 5, the carriage 47 is moved adjacent to the rib support hub 17 such that the outwardly extended portion of the flat members 58 extend beyond the width of the rib support hub. The outer ends of the flat members 58 are aligned to be in the same vertical plane as the outer end of the first ring of bricks to be laid.
The inner members 62 of the telescoping lateral span arms 60 are extended laterally outward from the ends of the center member 61 at the bottom of the brick support hub 54 to engage the tubing members 63 at their outer ends on opposite sides of the tunnel just below the horizontal diameter D of the arch and thereafter locked at the proper lateral extension by the lock screws 64 to maintain the brick support hub 54 centered. When properly positioned, the outer ends of the flat members 58 are aligned in the same vertical plane as the outer end of the first ring of bricks to be laid, and the slots 59 between the flat members 58 are aligned with the radial axis of the holes 21 in the wall of the rib support hub 17.
Referring again to FIG. 4 and 5 and to FIG. 6, starting on the 180° opposite sides of the tunnel at the horizontal diameter, each brick B is "hand buttered" (applying mortar) and placed against the curved surface S of the arch. As each brick is placed on the curved surface S, the pin end of a brick support strut 65 is placed on a flat surface 58 of the brick support hub 54 and compressed radially downward against the spring force of its inner compression spring and then released to engage the resilient end cap 68 at the outer end of the brick support strut 65 on the brick just placed such that the spring force presses the brick against the curved surface S. The end cap 68 of the brick support strut 65 is placed near one end of the brick (approximately the inward 1/3 of the brick length).
As shown in FIG. 6, this step is repeated sequentially working upward from the opposite sides of the arch until a complete arcuate "ring" of brick is completed. Each brick is secured with an individual brick support strut 65. The vertical rib support strut 28 which was used initially to maintain the position of the rib support hub 17 may be used to support the top center brick, or removed and replaced with a brick support strut 65 when installing the top center brick.
Referring now to FIGS. 7 and 8, after the brick support struts 65 have been installed, the rib support struts 28 are installed, starting from opposite sides of the arch, by placing the pin end of the rib support struts 28 into the holes 21 in the arcuate top wall 20 of the rib support hub 17 and compressing them radially downward against the spring force of their inner compression spring and then releasing them to engage the channel 40 at the top of each short length of tubing 38 on the approximate center of certain circumferentially spaced ones of the bricks which are supported by the brick support struts 65. The rib support struts 28 extend radially outward from the rib support hub 17 through the slots 59 between adjacent flat members 58 of the brick support hub 54. If the number and spacing of the brick support struts 65 make it difficult to install the rib support struts 28, the interferring brick support struts may be shifted or removed and re-installed as each rib support strut 28 is installed.
The circumferential spacing of the holes 21 in the arcuate top wall 20 of the rib support hub 17 correspond in direct relation to predetermined chord points (for example 14" or 16") on the semicircular ring of bricks installed on the curved surface of the arch. Thus, a channel 40 at the outer end of each rib support strut 28 will engage the center of every third or fourth brick along the circumference of the first ring of bricks.
As shown in FIG. 9, the elongate resilient rib member 46 is then installed in the channels 40 at the outer ends of the rib support struts 28. This is accomplished by starting at one side of the arch and compressing each rib support strut radially downward against the spring force of its inner compression spring, inserting a segment of the rib 46 into the channel 40 and then releasing the strut 28 to spring bias the rib 46 against the brick. After the rib 46 has been installed, it is spring biased radially outwardly by the spring force of the rib support struts 28 at the 14" or 16" circumferential chord segments. The material of the rib 46 is sufficiently resilient such that when curved along the inner diameter of the brick ring the segments of the rib between the 14" or 16" chord points will also firmly engage the bricks disposed between each third or fourth brick.
As shown in FIG. 10, after the first rib 46 has been installed along the inner diameter of the first ring of bricks, the previously installed brick support struts 65 are removed and a coupling member 41 is slid into each short square tubing 38 at the outer end of each rib support strut, but the lock screws 39 are not tightened. A second ring of bricks is then installed.
As shown in FIGS. 10 and 11, starting on the 180° opposite sides of the tunnel at the horizontal diameter, each brick B2 forming the second ring of bricks is "hand buttered" (mortar applied) and placed against the curved surface S of the arch. As each brick B2 is placed on the curved surface S, the pin end of a brick support strut 65 is placed on a flat surface 58 of the arcuate wall 57 of the brick support hub 54 and compressed radially downward against the spring force of its inner compression spring and then released to engage the resilient end cap 68 at the outer end of the brick support strut 65 on the brick just placed such that the spring force presses the brick against the curved surface S. As described previously, the end cap 68 of the brick support strut is placed near the inward 1/3 of the brick length. This step is repeated sequentially working upward from the opposite sides of the arch until the second arcuate "ring" of brick is completed. Each brick B2 of the second ring of bricks is secured with an individual brick support strut 65.
After the brick support struts 65 have been installed on the second ring of bricks, the coupling members 41 are positioned such that the channel 44 of each coupling member 41 is positioned on the approximate center of the brick adjacent the previously installed rib support strut and then the lock screws 39 are tightened (FIG. 10).
As shown in FIG. 12, after the coupling members 41 have been secured, a second rib 46 is installed in the channels 44 of the coupling members 41. This is accomplished by starting at one side of the arch and compressing each previously installed rib support strut 28 radially downward against the spring force of its inner compression spring which carries the coupling member 41 with it, inserting a segment of the rib 46 into the channel 44 of the coupling 41 and then releasing the strut 28 to spring bias the rib against the brick. This will not affect the previously installed rib because it is still spring biased outwardly by the spring force of the other rib support struts 28 adjacent the one being compressed which are still spring biased outwardly and the previously installed rib remains firmly engaged on the previously installed ring of bricks.
After the second rib has been installed along the inner diameter of the second ring of bricks B2, the previously installed brick support struts are removed, and the carriage is moved along the track 11 away from the previously installed rib support hub 17. A second rib support hub 17 is installed on the track 11, and positioned such that the holes 21 in its outer wall 20 are aligned at the center of the third ring of bricks B3 to be installed, as described previously. A tubular spacer extension 45 is installed in the end of the previously installed coupling member 41, but the lock screws 42 are not tightened.
The carriage 47 is then moved to a position adjacent the rib support hub 17 such that the outwardly extended portion of the flat members 58 extend beyond the width of the rib support hub and the outer ends of the flat members 58 are aligned to be in the same vertical plane as the outer end of the third ring of bricks B3 to be laid, and the telescoping lateral span arms 60 are extended laterally outward to engage the tubing members 63 at their outer ends on opposite sides of the tunnel and locked to maintain the brick support hub 54 centered. When properly positioned, the outer ends of the flat members 58 are aligned in the same vertical plane as the outer end of the third ring of bricks B3 to be laid, and the slots 59 between the flat members 58 are aligned with the radial axis of the holes 21 in the rib support hub 17, and the steps of hand buttering and placing the bricks, and securing each one with a brick support strut is repeated, working upward from the opposite sides of the arch until the third arcuate ring of bricks is completed, as previously described with the first ring of bricks.
After the brick support struts have been installed on the third ring of bricks, and starting from opposite sides of the arch, a second series of rib support struts 28 are installed, as described previously, by placing their pin ends into the holes 21 in the second rib support hub 17 and compressing them radially downward and then releasing them to engage the channel 40 at their outer ends on the approximate center of certain circumferentially spaced ones of the third ring of bricks B3. As the rib support struts are being compressed or released, the spacer extensions 45 extending outwardly from the previously installed couplings 41 are slid into the short lengths of tubing 38 at the outer ends of the rib support struts 28 and the lock screws 39 and 42 are tightened when the channel 40 is centered on the brick B3.
After the spacer extensions 45 have been secured, a third rib 46 is installed in the channels 40 at the outer ends of the second series of rib support struts 28 by starting at one side of the arch and compressing each second series of rib support struts 28 radially downward against the spring force of its inner compression spring which carries the extension and adjacent coupling with it, inserting a segment of the third rib 46 into the channel 44 of the coupling 41 and then releasing the strut 28 to spring bias the rib against the brick. This will not affect the previously installed ribs because they are still spring biased outwardly by the spring force of the other rib support struts 28 of the second series and the couplings and rib support struts adjacent the one being compressed.
After the third ribs have been installed, another coupling 41 is slid into each short square tubing 38 at the outer end of each rib support strut of the second series, but the lock screws are not tightened. A fourth ring of bricks B4 is then installed.
Starting on the 180° opposite sides of the tunnel at the horizontal diameter, each brick forming the fourth ring is "hand buttered" (mortar applied) and placed against the curved surface of the arch. As each brick B4 is placed on the curved surface S, the pin end of a brick support strut 65 is placed on a flat surface 58 of the brick support hub 54 and compressed radially downward against the spring force of its inner compression spring and then released to engage the resilient end cap 68 at the outer end of the brick support strut on the brick just placed such that the spring force presses the brick against the curved surface, as described previously. This step is repeated sequentially working upward from the opposite sides of the arch until the fourth arcuate "ring" of brick is completed and each brick B4 of the fourth ring of bricks is secured with an individual brick support strut.
After the brick support struts have been installed on the fourth ring of bricks, another series of coupling members are positioned such that the channel of each coupling is positioned on the approximate center of the brick adjacent the previously installed rib support strut and then their lock screws are tightened. After the coupling members have been secured, a fourth rib is installed in the channels of the couplings in the manner described previously.
After the fourth rib has been installed along the inner diameter of the second ring of bricks, the previously installed brick support struts are removed, and the carriage is again moved along the track away from the previously installed rib support hub, and the next rib support hub is installed on the track, and positioned such that the holes in its outer wall are aligned at the center of the next ring of bricks to be installed, and the steps of installing the spacer extensions, brick support struts, rib support struts, couplings, and ribs, are repeated
If the mortar holding the first ring of bricks has set or cured, the first installed rib support struts, rib, couplings, extensions, and rib support hub may be removed and reused. These steps are repeated moving longitudinally along the length of the tunnel and installing a rib support hub at the center of each third ring of bricks until the final ring of bricks is installed.
Although the above procedure describes a series of rib support struts being installed on each third ring of bricks, it should be understood that several extensions and couplings may be installed between the series of longitudinally spaced rib support struts. Preferably, the number of components are correlated to the setting or curing time whereby the first and subsequently installed components can be removed and reused over and over sequentially as the work progresses continuously to reduce the number of components required and to eliminate having to wait for the mortar to set.
While this invention has been described fully and completely with special emphasis upon a preferred embodiment, it should be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein. | A first hub is positioned at the center of a curved surface to be lined with bricks. A second hub is positioned adjacent the first and has an outer wall extending beyond the width of the first hub in radially spaced relation with a series of circumferentially spaced slots therein. Mortared bricks are placed sequentially against the curved surface and supported by telescopic spring-loaded brick support struts placed on the second hub to extend generally radially outward therefrom and engage each mortared brick to form a ring of bricks each pressed against the curved surface by a brick support strut. Telescopic spring-loaded rib support struts are sequentially placed on the first hub to extend radially outward through the slots of the second hub and engage the approximate center of certain circumferentially spaced bricks of the ring of bricks. Each rib support strut is sequentially contracted and an elongate resilient rib is installed between the outer end of the rib support struts and the inner diameter of the ring of bricks such that the rib member and rib support struts exert a radial outward force thereon. A coupling is connected to the rib support struts and a second ring of bricks are installed adjacent the first ring and supported by brick support struts while a second rib is installed in the couplings. Subsequent rings of bricks are installed by removing the brick support struts, installing another first hub and repositioning the second hub adjacent thereto and repeating the process. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a system and method for estimating a state-of-charge (SOC) of a battery, and, more particularly, to a system and method for estimating the SOC of a battery using changes in the size or pressure of the battery.
[0003] 2. Discussion of the Related Art
[0004] Electric vehicles are becoming more and more prevalent. These vehicles include hybrid vehicles, such as extended range electric vehicles that combine a battery and a main power source, such as an internal combustion engine, fuel cell system, etc., and electric only vehicles, such as battery electric vehicles. All of these types of electric vehicles employ a high voltage battery that can be different battery types, such as lithium-ion, nickel metal hydride, lead acid, etc. The battery system can include individual battery modules where each battery module may include a certain number of battery cells, such as twelve cells.
[0005] Because batteries play an important role in powering electric vehicles and hybrid vehicles, effective battery control and power management is essential to vehicle performance, fuel economy, battery life and passenger comfort. Accurate knowledge of the SOC is critical for proper control of the battery system in an electric vehicle to obtain long battery life and good fuel economy. Because the SOC cannot be directly measured while operating the vehicle, a battery controller needs to predict and estimate the SOC in real-time using other battery parameters such as open circuit voltage and current.
[0006] It is well known by those skilled in the art that battery dynamics are generally non-linear and highly dependent on battery operating conditions, which means that an accurate estimation of battery SOC cannot be guaranteed. One approach to estimate the SOC of a battery is to monitor the battery's open circuit voltage. In general, the higher the open circuit voltage the higher the SOC. However, open circuit voltage is inherently difficult to use to accurately estimate the SOC because the battery voltage is influenced by many factors, not just SOC, for example, the temperature, short term charging history, long-term vehicle driving history, age of the battery, etc. For most battery cell chemistries, the voltage level decreases only slightly, if at all, as the battery starts discharging. At some point at a lower SOC the voltage level starts to decrease at a faster rate.
[0007] Lithium-ion batteries have proven to be promising for hybrid electric vehicles. Estimating the SOC is significantly more challenging for lithium-ion batteries than the older nickel based technology because lithium-ion based batteries maintain their voltage level for a long time even as the SOC drops. The voltage of a lithium ion battery will not change significantly in a range from about 20% to 80% SOC.
[0008] Another way the battery controller can estimate SOC is to calculate the electric charge flowing into and out of the battery by integrating the current over time. One problem with this approach is that the estimated SOC drifts away from the real SOC over time. Therefore, the battery controller needs to reset or readjust the estimated SOC periodically to match the real SOC. One way to reset the estimated SOC is to charge the battery to 100%. However, the vehicle driver may charge the battery when the SOC is down to 30%. The driver may charge the battery for the next trip, but at the start of the next trip, the battery might have been recharged only to 70% SOC. The vehicle could then be driven until the battery drains to 40% SOC and then charged again, still not reaching 100% SOC before the vehicle is off on another trip. Given this type of scenario, resetting the SOC when the charge is at 100% is problematic. Another option is to discharge the battery to 0% SOC, but, as with charging to 100% SOC, this is detrimental to the battery.
[0009] What is needed is a way to estimate the SOC of a battery that overcomes the limitations of the current SOC estimation techniques.
SUMMARY OF THE INVENTION
[0010] In accordance with the teachings of the present invention, a system and method for monitoring a state-of-charge (SOC) of a battery are disclosed, where the system includes a sensor and a controller. The sensor provides a measurement signal that can track a nominal volume value by either measuring a dimension or pressure of the battery, where the nominal volume is the volume that the electrolyte, anode, cathode and current collectors would occupy if unconstrained. The controller is programmed to use a function to estimate the SOC from the measurement signal. The function can be established after constructing a charging and discharging curve of the battery that graphs the measurement signal compared to the SOC of the battery and finding a characteristic shape.
[0011] Additional features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an illustration of a vehicle having a battery and a controller;
[0013] FIG. 2 is a front view of a foil pouch battery cell;
[0014] FIG. 3 is a side view of the foil pouch battery cell;
[0015] FIG. 4 is a side view of a battery module including a set of pouch battery cells constrained from expanding;
[0016] FIG. 5 is a graph showing pressure as a battery is charged and discharged; and
[0017] FIG. 6 is an exemplary flowchart showing one possible embodiment for using the change in the nominal volume of the battery to estimate its SOC.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] The following discussion of the embodiments of the invention directed to monitoring the state-of-charge (SOC) of a battery is merely exemplary in nature, and is in no way intended to limit the invention or its applications or uses. For example, the battery controller techniques discussed below have particular application for electric vehicles and lithium-ion batteries. However, as will be appreciated by those skilled in the art, these SOC estimation techniques may have application for other batteries that do not involve electric vehicles, and use other battery chemistries.
[0019] Batteries are made of various chemistries and physical structures, where some battery chemistries are known to change in volume based on battery SOC, for example, expanding as the SOC increases. Lithium-ion batteries provide one example of such expansion and are known to build up pressure when they are in a rigid container because of the lithium-ion movement between cathode and anode. The rigid container has to be strong enough to avoid rupture from the pressure exerted by the expanding lithium-ion electrolyte, anode, cathode and current collectors. One way to avoid having to use a strong structure is to allow the volume to increase by building a battery that is contained within a pouch, also known as a soft pack, that allows the expansion to occur so pressure does not build up.
[0020] FIG. 1 is a simple illustration of a vehicle 10 having a battery 12 and a battery controller 14 . The controller 14 controls the charging of the battery 12 and the use of the battery 12 to propel the vehicle 10 .
[0021] FIG. 2 is a front view and FIG. 3 is a side view of a pouch battery cell 20 . The pouch cell 20 has a positive terminal 22 and a negative terminal 24 and a foil covering 26 that provides a gastight seal of the electrolyte, anode, cathode and current collectors of the battery cell 20 . The pouch configuration allows the electrolyte, anode and cathode of the battery cell 20 to expand and contract.
[0022] FIG. 4 is a side view of a battery module 40 including a battery cell set 42 having, for example, twelve to sixteen of the pouch battery cells 20 , where a foam layer (not shown) may be positioned between the cells 20 . The battery cell set 42 is positioned within and constrained by a rigid container 44 , where a pressure sensor 46 is provided within the container 44 . The pouch battery cells 20 are stacked so that flat surfaces of the cells 20 are positioned next to each other in direct or alternating sequence so that the battery cells 20 can be electrically coupled in parallel or series as appropriate. The thickness of the flat surfaces of the pouch battery cells 20 tends to increase and decrease when charging and discharging the cells 20 . Charging the battery module 40 can cause the cell set 42 to expand and contract, where the battery cell set 42 is constrained by the container 44 , so that the pressure in the container 44 as measured by the sensor 46 changes.
[0023] The pouch battery cell 20 has a preferred pressure that optimizes its operation and is available from the pouch battery cell designer or manufacturer. The container 44 can compress the battery cell set 42 to have a nominal starting pressure based on the preferred pressure.
[0024] A set of lithium-ion battery cells was tested in a rigid container and a consistent relationship was found between the change in pressure exerted by a set of lithium-ion pouch battery cells and the SOC of the cells during charging and discharging.
[0025] FIG. 5 is a graph 60 showing the pressure as the battery module 40 is charged and discharged. The graph 60 displays the SOC along the horizontal axis 62 ranging from 0% SOC to 100% SOC. The pressure measurement is on the vertical axis 64 ranging from a nominal pressure 66 to a maximum pressure 76 . The charging curve starts at 0% SOC at the nominal pressure 66 , and as the battery module 40 is charged, the SOC increases with a consistent slope in region 68 . As the battery module 40 continues charging, at a little less than 10% SOC, the charging curve continues along a slightly steeper slope in region 70 until it reaches a charging local-maximum pressure 72 at a little more than 30% SOC. Next, as the battery module 40 continues to charge the pressure decreases and goes into a trough 74 until about 80% SOC, where the pressure builds again until the pressure reaches point 76 at 100% SOC. As the charged battery module 40 sits and waits for use, the pressure will decrease.
[0026] Later, after the fully charged battery module 40 has waited and cooled to a steady state condition, the discharge cycle is started. The pressure starts at point 78 . The discharging curve enters a trough 80 where the pressure decreases until the SOC reaches a local minimum at about 60% SOC, at which point the pressure starts to increase until it reaches a local-maximum pressure 82 . As the SOC continues to decrease the pressure decreases at a steady rate in region 84 until it reaches the region 68 , at less than 10% SOC, where the slope of the discharge continues at the same slope as was seen during earlier charging.
[0027] The fact that the battery cell set 42 expands and contracts in a repeatable characteristic pattern can be used to provide an estimated SOC of the battery module 40 . Testing showed that a dimension change, particularly the thickness of a pouch cell, which was measured as a change in pressure, can be used to determine the SOC of the battery cell set 42 . The characteristic shape may vary in average pressure, but not in shape, and the characteristic feature (local maximum) is always visible in a graph that compares the SOC of the battery module 40 to the pressure while charging or discharging. During operation of the battery module 40 , the characteristic feature can be used to determine the SOC of the battery module 40 .
[0028] There are any number of ways that a battery module can be constructed to measure a change in its nominal volume, where the nominal volume is defined as the volume the electrolyte, anode, cathode and current collectors would occupy if not constrained. A change in the nominal volume can result in a change in a dimension or pressure. The change in size, or dimension, will occur if the size is not constrained. The change in dimension can be monitored with a measurement that includes the size of the cell housing. The change in pressure will occur if the dimension is constrained. A battery can have changes in both dimension and pressure, but one will dominate and that one can be used to estimate the nominal volume, or both the dimension and pressure could be used to estimate the change in nominal volume. There could be a sensor on each battery cell, or one sensor for a group of battery cells, as is shown in the battery module 40 . A set of pouch battery cells would produce larger movement then a single pouch battery cell and that could provide increased accuracy in measuring the change in size. Other options are available to measure the nominal volume, for example, a sensor could measure the tension on a band wrapped around a battery cell or a set of cells. Alternatively, a tensioner could keep the band at a constant tension by reeling out and retracting the band as necessary, and then the total length of the band would indicate circumference, which would indicate volume. A band could be useful for other battery designs like cylindrical, prismatic or other. Another option would be to place a pressure sensor inside the metal casing of the battery to measure the pressure. If the temperature of a battery is regulated by a bath of liquid, then the amount of displaced fluid could give an indication of the change in volume of the battery. Many different and alternative configurations and sensors could be used that go well beyond this list to detect the change in nominal volume of the battery to estimate the SOC of the battery.
[0029] Although this specification discloses the details for measuring the expansion of a lithium-ion battery, any battery chemistry could be used that results in a change in the nominal volume. Other battery chemistries may have completely different charging and discharging curves. To apply this approach for estimating SOC to other chemistries the steps involved would be to generate the charging and discharging curves by testing and examining the curves for repeatable sections. If there is a repeatable section that provides a characteristic feature, then that characteristic feature could be used as a good location to reset or readjust an electrically estimated SOC of the battery module 40 . A characteristic feature is a curve feature that is distinctive enough for an algorithm to determine. Examples of characteristic features would be a local maximum, a local minimum or a point of inflection. The graph 60 shows some examples of characteristic features with the charging local maximum 72 and the discharging local-maximum 82 . In one embodiment an algorithm could detect the discharging local-maximum 82 by tracking the pressure when the battery module 40 is discharging and when the pressure switches from increasing to decreasing that would indicate the location of the local-maximum 82 .
[0030] FIG. 6 is a flowchart 120 showing one possible embodiment for using the change in the nominal volume of the battery module 40 to estimate its SOC. The flowchart 120 starts at box 122 where the process determines the nominal pressure based on the battery design. Next, at box 124 , the process determines a measurement signal that indicates the change in the nominal value. One option is to measure the pressure that the battery cells 20 exert when constrained in the container 44 . At the box 126 the process provides a sensor, for example, the pressure sensor 46 on the battery cell set 42 . Next, at box 128 , the algorithm runs tests on the battery module 40 to create charging and discharging curves on a graph with the horizontal axis being SOC and the vertical axis being the measurement signal pressure, for example, the graph 60 . Next, at box 130 , the process creates a function that represents the graph 60 , where the measurement signal can be used to estimate the SOC. The function can use any appropriate method, for example, an equation, a lookup table, an algorithm, etc. Finally, at box 132 , the battery is in operation and a real-time measurement signal can be used contemporaneously to provide a physically estimated SOC, where a real-time measurement signal is one providing the present state of the battery module 40 .
[0031] Traditional electrical SOC estimation techniques of a battery may be more accurate on a local basis, but the physically estimated SOC can be more accurate over time because the physically estimated SOC can be more independent of temperatures and other factors. Because the physically estimated SOC can be more accurate and independent it can be used to reset or readjust an electrically estimated SOC, especially because the electrically estimated SOC drifts away from the real SOC over time.
[0032] A battery controller can use the electrically estimated SOC of the battery in combination with the physically estimated SOC to provide a more reliable prediction of the SOC. One approach is to use a characteristic feature to reset or readjust the electrical estimated SOC. It would be good to have a characteristic feature on the pressure/SOC graph to reliably locate the position on the charging or discharging curve. The occurrence of the characteristic feature can be used to reset or readjust the electrically estimated SOC. Looking at the graph 60 there is a characteristic feature of the discharge local-maximum 82 . When discharging from a high SOC a controller could use the local-maximum 82 to determine the position on the discharging curve and then reset or readjust the electrical estimated SOC, being confident of the location on the curve.
[0033] It is preferred to reset or readjust the SOC of the battery when approaching 0% SOC because a 5% estimation error at 90% is not likely important, however, the same 5% makes a big difference when approaching 0% SOC. For example, a 5% over estimation of a 10% SOC would give the impression to the driver that they can make it the whole 10 miles to refuel at home when the reality is the vehicle can only travel 6.6 miles and the driver will end up stranded on the side of the road.
[0034] The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
[0035] Give all terms used in the claims their broadest reasonable construction and their ordinary meaning as understood by those skilled in the art. Use of the singular articles such as “a”, “the”, “said”, etc. should be read to recite one or more of the indicated elements. | A system and method for monitoring a state-of-charge (SOC) of a battery, where the system includes a sensor and a controller. The sensor provides a measurement signal that can track changes of a nominal volume of the battery by either measuring a size or pressure of the battery, where the nominal volume is the volume that the electrolyte, anode, cathode and current collectors would occupy if unconstrained. The controller is programmed to use a function to estimate the SOC from the measurement signal. The function can be established after constructing and finding a repeatable charging and discharging curve of the battery that graphs the measurement signal compared to the SOC of the battery. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a control circuit for driving motor vehicles and more particularly to a control circuit for inititating the acceleration and deceleration of motor vehicles when preselected speeds of the vehicle are reached.
In general, internal combustion engines for motor vehicles present a high efficiency when operated at high loads, in other words, the rate of fuel consumption is small, while at low loads they present a decreased efficiency, that is, the rate of fuel consumption is large. Motor vehicles have preset engine outputs and transmission gear ratios so as to meet a wide range of driving conditions such as acceleration and hill-climbing. Therefore, even when driving on a flat road at a constant medium or low speed, the engine is in a light load condition, resulting in a low engine efficiency, i.e. the rate of fuel consumption has been large.
Conventional engines continue rotating even when vehicles are in a hill-descending, coasting or stationary condition, thus consuming a considerable amount of fuel. Also, when a motor vehicle is running on a flat road at a constant speed, but at the ordinary vehicle speed range, that is, below 100 km/h, the engine load is light, particularly at low speeds, so that the engine efficiency is low, resulting in a large rate of fuel consumption.
In an attempt to eliminate the above-mentioned drawbacks, there has been proposed a fuel-saving driving apparatus for internal combustion engines (U.S. Patent application Ser. No. 653,027) which includes a one-way clutch provided before or after the transmission to allow actuation only from the engine side so that, when the rotational frequency on the driven side is higher, only the driven side is kept freely rotatable, and in which there is provided a system to allow the engine to start when the driver steps on an accelerator pedal and to stop when the pedal is released, whereby through pedal operation the engine is intermittently operated in a high load condition which affords a high efficiency. The average engine output is adjusted by changing the ratio of time between operation and stop to thereby save fuel.
When such a fuel-saving driving apparatus for internal combustion engines is used, a motor vehicle is accelerated in the region of high engine efficiency, that is, low fuel consumption rate, to a speed greater than the desired speed. There after, the accelerator pedal is released to stop the engine while the vehicle is allowed to coast to a speed less than the desired speed, where, again, the accelerator pedal is depressed to start the engine and the vehicle is accelerated in the high efficiency region. This operation is continuously repeated so as to give an average speed equivalent to the desired speed, whereby it becomes possible to save fuel.
As is apparent from what has been summarized above, however, in such fuel-saving driving apparatus for internal combustion engines the driver himself compares the vehicle speed with the desired speed at all times and depresses or releases the accelerator pedal accordingly to the control inititation of vehicle acceleration and deceleration. This requires an extra attentiveness of the driver and causes dispersion because the judge is a human being. Thus, the vehicle is not always running in the optimum driving condition when viewed from the standpoint of fuel-saving driving.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide an apparatus for controlling the initiation of vehicle acceleration and deceleration to achieve an automatic vehicle acceleration and deceleration between preset upper-limit and lower-limit vehicle speeds.
Another object of the invention is to provide an apparatus for controlling the initiation of acceleration and deceleration of the motor vehicle in which the engine is in no danger of overrunning when the transmission is in neutral or low-speed position or the clutch is disconnected.
Yet another object of the invention is to provide an apparatus for controlling the initiation of acceleration and deceleration of the motor vehicle with which a driver may control a throttle valve through an accelerator pedal when he wishes to control initiation of acceleration or discontinue coasting in an urgent need.
Another object of the invention is to provide an apparatus for controlling the initiation of acceleration and deceleration of the motor vehicle with which a driver may set upper-limit and lower-limit vehicle speeds.
According to the present invention, the above-mentioned object is attained by an appartus for controlling the initiation of acceleration and deceleration of motor vehicles, which apparatus comprises an acceleration/deceleration initiation control circuit adapted to compare a vehicle speed voltage from a vehicle speed sensor with a preset upper-limit vehicle speed voltage and a preset lower-limit vehicle speed voltage and to emit with hysteresis an "off" signal in response to a vehicle speed voltage greater than the preset upper-limit vehicle speed voltage and an "on" signal in response to a vehicle speed voltage less than the preset lower-limit vehicle speed voltage, an electromagnetic relay connected to said acceleration/deceleration initiation control circuit and adapted to supply an electric current from a battery to an ignition circuit in response to the "on" signal and to cut off the current in response to the "off" signal, and a throttle control device connected to said electromagnetic relay and adapted to open a throttle valve in response to the "on" signal.
That is, the apparatus for controlling acceleration and deceleration of motor vehicles according to the present invention has an acceleration/deceleration initiation control circuit adapted to turn off when the vehicle speed voltage has become greater than the preset upper-limit vehicle speed voltage and to turn on when the vehicle speed voltage has become less than the preset lower-limit vehicle speed voltage, and in response to its "on" signal the starter, the ignition circuit and the throttle control device are energized to start operation of the engine and thus the vehicle is accelerated. On the other hand, in response to an "off" signal from the acceleration/deceleration initiation control circuit, the engine is stopped (turned off), allowing the vehicle to coast. Thus, acceleration/deceleration driving is effected automatically between the preset upper and lower vehicle speed limits, thereby minimizing the rate of fuel consumption.
Other and further objects, features and advantages of the invention will appear more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit diagram illustrating an embodiment of the apparatus for controlling the initiation of acceleration and deceleration of motor vehicles according to the present invention;
FIG. 2 is a sectional side elevation illustrating an embodiment of the throttle control means used in FIG. 1;
FIG. 3 is a front view of the throttle control means of FIG. 2; and
FIG. 4 is a circuit diagram illustrating another embodiment of the acceleration/deceleration initiation circuit used in the apparatus for controlling the initiation of acceleration and deceleration of motor vehicles according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made below to the accompanying drawings for a full illustration of embodiments of the present invention.
FIG. 1 is an electric circuit diagram illustrating an embodiment of the apparatus for controlling the initiation of acceleration and deceleration of motor vehicles according to the present invention. When a main switch 10 is closed, a water temperature sensor 12 mounted in the cooling system is kept closed when the temperature of the cooling water for cooling the engine (not shown) is low and so current flows from battery 14 to the solenoid of an electromagnetic relay 16, thus causing its contact to be closed. As a result, current from the battery 14 flows through an ignition circuit 18 and a starter 20 and the engine starts. Upon starting of the engine, an ignition pulse is converted into an analogue signal proportional to the rotational frequency of the engine by means of a DA converter 22 and is fed to one input of a comparator 24. The comparator 24 compares such analogue signal with the set voltage fed to the other input from a voltage regulator circuit 26 and, when the rotational frequency of the engine exceeds the set value, in other words, when the engine starts, it produces an output to actuate the solenoid of an electromagnetic relay 28. As a result, the contact of the relay 28 opens, the starter 20 stops and only the engine continues warming up.
Even if the warming-up causes the temperature of the cooling water to rise and the water temperature sensor 12 to open, if the negative pressure of a brake booster (not shown) is low, a pressure sensor 30 in communication therewith is kept closed and current flows therethrough into the ignition circuit 18 and the engine continues rotating. Even if the negative pressure in the brake booster becomes high and causes the pressure sensor to open, if the voltage of the battery 14 is lower than the set voltage from the voltage regulator circuit 26, the comparator produces an output to excite the solenoid of the electromagnetic relay 16, thus causing its contact to be closed and the engine continues rotating, thereby charging the battery 14.
Assuming that the temperature of the cooling water, the negative pressure in the brake booster and the battery voltage are all high, the electromagnetic relay 16 for shorting the acceleration/deceleration initiation control circuit is opened and the engine stops, but when an accelerator pedal (not shown) is depressed, a switch 34 in interlocking relation therewith turns on and current flows through the ignition circuit 18 and starter 20, so that, as set forth above, the engine again starts and continues producing output and the vehicle velocity on driving becomes high. When the switch 34 turns on, a diode D1 is connected in the direction shown so as to block current flow towards throttle control means as will be described later. If the vehicle velocity exceeds the desired velocity and deceleration is desired, the accelerator pedal is released to turn the switch 34 off and the ignition circuit 18 also turns off, thus causing the engine to stop, but the vehicle coasts by virtue of a one-way clutch (not shown). If the vehicle velocity becomes lower than the desired velocity and acceleration is desired, the accelerator pedal is depressed to turn the switch 34 on and the ignition circuit 18 and the starter 20 again start operation, which causes the engine to start. When a change-over switch 36 is off, acceleration and coasting driving (with the averaged speed made as the desired speed) are repeated in such a way by the driver whereby it is possible to effect driving with minimized rate of fuel consumption.
When the change-over switch 36 is turned on and when the transmission is not in neutral or low-speed position and the clutch is connected, switches 36a and 36b are on, so that the acceleration/deceleration initiation control circuit 38 operates with current fed from the battery and turns on or off according to the vehicle speed voltage from a vehicle speed sensor 40 such as a d.c. motor, thus causing an electromagnetic relay 42 to turn on or off. That is, when at the time of acceleration a comparator 46 judges that the vehicle speed voltage VS is lower than the set voltage VH from an upper-limit vehicle speed setting means 44, the comparator 46 issues a 1 (high) signal. On the other hand, when VS is lower than the set voltage VL from a lower-limit vehicle speed setting means 52, a comparator 54 issues a 1 (high) signal and a D type flip-flop 48 puts out a 1 to cause a transistor Tr1 to turn on, so that the contact of the electromagnetic relay 42 closes, causing current flow through the ignition circuit 18, and the engine does not stop. When the electromagnetic relay 42 is closed and if at this moment the accelerator pedal is depressed and the switch 34 closed, an electromagnetic relay 96 turns on, resulting in a current flow through the solenoid of a solenoid valve 50 and a throttle valve (not shown) is opened as will be described later. When the relay 42 is on, a diode D2 is connected in the direction shown to block current flow through the relay 96. When as a result of acceleration the vehicle speed exceeds the lower-limit speed, the vehicle speed voltage VS becomes larger than the set voltage VL and the comparator provides a 0 (low) signal, but the D type flip-flop 48 still puts out a 1 and gives no change to Tr1, etc. When a further acceleration causes the vehicle speed to exceed the upper-limit velocity, the vehicle speed voltage VS becomes larger than the set voltage VH, the comparator 46 issues a 0 (low) signal, the D type flip-flop 48 puts out a 0 and the transistor Tr1 turns off, so that the contact of the relay 42 opens and the ignition circuit 18 turns off, thus causing the engine to stop and the vehicle start coasting.
When at the time of deceleration the vehicle speed becomes less than the upper-limit vehicle speed, the vehicle speed voltage VS becomes less than the set voltage VH and the comparator 46 produces a 1 (high) signal, but the D type flip-flop still puts out a 0 and gives no change to the transistor TR1, etc. If a further deceleration causes the vehicle speed voltage VS to be lowered below the comparison voltage VL from the lower-limit vehicle speed setting means 52, the comparator 54 produces a 1 (high) signal and the D type flip-flop puts out a 1 to cause the transistor Tr1 to turn on and current flows through the ignition circuit 18, whereupon the solenoid valve is turned on to open the throttle valve. When the vehicle is accelerated resulting in the vehicle speed voltage VS becoming higher than the upper-limit set voltage VH, the solenoid valve 50 is turned off and the vehicle again starts coasting as set forth above. Thus the vehicle is automatically accelerated and decelerated between the preset upper-limit and lower-limit vehicle speeds, so that the vehicle is kept in an optimum driving condition in point of the rate of fuel consumption without requiring an extra attentiveness of the driver. In this case, if the acceleration/deceleration initiation control circuit 38 is actuated when the transmission is in neutral or lowspeed position and the clutch disconnected, the engine may undergo overrevolution. To prevent this, a transmission switch 36a and a clutch switch 36b are provided, whereby when in such a driving condition at least one of the switches 36a and 36b is turned off to render the acceleration/deceleration initiation control circuit 38 inoperative.
FIG. 2 is a sectional side elevation illustrating an embodiment of the throttle control means used together with the apparatus of FIG. 1, and FIG. 3 is a front view thereof. These figures show the state of the solenoid valve 50 being on. When the solenoid of the solenoid valve 50 is excited as mentioned above, a plunger 58 is moved to the left as shown against the compressive force of a return spring 56, so that the negative pressure or vacuum from an intake manifold (not shown) passes through a pipe 60 and then an opening at the right side in the plunger 58 and so through a pipe 62 into a negative pressure or vaccum chamber 64. A casing 66, which is located at the side opposite to the nagative pressure chamber 64 relative to a diaphragm 68, is in a largely bored shape leaving an arm 70 as shown in FIG. 3; therefore, the diaphragm 68 is moved to the right due to the differential pressure between the atmospheric pressure and the negative pressure. As a result, an arm 72, which is attached to the diaphragm 68, pushes a throttle linkage 74, which causes a throttle valve (not shown) connected thereto to open. When the throttle valve is opened, the negative pressure in the negative pressure chamber 64 is decreased, so that the throttle valve is slightly closed. In this way, the throttle valve is held at a degree of opening at which the differential pressure between the atmospheric pressure and the negative pressure and the restoring force of the return spring 76 balance, and the vehicle is accelerated.
When the vehicle speed exceeds the upper-limit value, the contact of the electromagnetic relay 42 opens and the solenoid of the solenoid valve 50 is de-energized, so that the plunger 58 is moved to the right by means of the return spring 56 whereby the negative pressure chamber 64 is brought into communication with the atmosphere through the pipe 62, a through hole at the left side in the plunger 58 and a port 78 which communicates with the atmosphere. As a result, the diaphragm 68 is moved to the left by means of the return spring 76 and so the arm 72 is also moved to the left, which causes the throttle valve to close. At the same time, as hereinbefore described, the ignition circuit 18 turns off and the engine stops, and thus the vehicle starts coasting. When as a result of the coasting the vehicle speed goes below the lower-limit value, the ignition circuit 18 again turns on, so that the throttle valve is opened and the vehicle accelerated as mentioned above. Thus the vehicle is automatically controlled in terms of the initiation of its acceleration and deceleration so that it is kept in an optimum driving condition with respect to the rate of fuel consumption.
Adjusting means 80, which is attached to the extended part of a case 66 and which is composed of, for example, bolt and nut, adjusts the resorting force of the return spring 76 to thereby adjust the throttle opening. The return spring 76 is anchored to fixed members 81 and 82 so that it may operate by both compression and tension. A length adjusting part 84, which is mounted at an intermediate portion of the arm 72, adjusts the relative positional relation between the arm 72 and the linkage 74.
FIG. 4 is a circuit diagram illustrating another embodiment of the acceleration/deceleration initiation control circuit used in the apparatus for controlling acceleration and deceleration of motor vehicles according to the present invention. When the vehicle stops, a zero voltage level is fed to the minus input of the comparator 90 so that the comparator 90 puts out a 1 signal. As a result, the transistor Tr1 turns on and the relay 42 also turns on to close its contact, so that the solenoid valve 50 turns on and the throttle valve is opened and thus the vehicle is accelerated. Since the 1 output of the comparator 90 is reduced to a 0 by means of an inverter 92, the transistor Tr2 turns off and the set voltage at the comparative input terminal of the comparator 90 becomes a voltage VH which is determined by resistors R0, R1 and R2.
When the vehicle is accelerated, gaining in speed and the vehicle speed voltage VS exceeds the set voltage VH, the output of the comparator 90 reverses into a 0 state. Consequently, the transistor Tr1 turns off and the relay 42 also turns off, so that the ignition circuit 18 turns off and stops the engine whereupon the throttle valve is closed. When the comparator 90 puts out a 0, the output of the inverter 92 becomes a 1 and the transistor Tr2 turns on, so that the voltage at the comparative input terminal of comparator 90 lowers to the set voltage VL which is determined by only the resistors R0 and R1.
When as a result of the coasting the vehicle speed voltage VS lowers below the set voltage VL, the comparator 90 again reverses, the relay 42 operates and the vehicle begins accelerating again whereupon the voltage at the comparative input terminal of comparator 90 again rises to toward the set voltage VH. In this way, the acceleration and deceleration points for a vehicle are automatically controlled.
With the acceleration/deceleration initiation control circuit according to the present invention, as set forth hereinbefore, if the changeover switch 36 is kept on, the starting and stopping of the engine and also the control of the throttle valve can automatically be performed to accomplish an acceleration/deceleration driving. When the driver is confronted with an urgent case in which he wishes to control acceleration or discontinue coasting, he may release the accelerator pedal whereby the relay 96 turns off and consequently the solenoid 50 also turns off and the arm 72 reverts to the original position, thus allowing the throttle valve to be free. Depressing the accelerator pedal turns the ignition circuit 18 on and the starter 20 also turns on, so that if the vehicle is coasting the engine starts and assumes the same state as ordinary vehicles, that is, the state without the present apparatus. Since the acceleration/deceleration control circuit can set the upper-limit vehicle speed and the lower-limit vehicle speed for acceleration/deceleration driving independently, a driving method can be set according to traffic condition. But when traffic is not heavy, lowering the lower-limit vehicle speed as far as possible would contribute to a smaller rate of fuel consumption. | An internal combustion engine fuel saving control system is disclosed in which acceleration of a vehicle is initiated in a region of high engine efficiency, i.e., low fuel consumption, and continues until the actual vehicle speed equals a first preset speed which is greater than the desired traveling speed of the vehicle. When the control system detects that the actual vehicle speed is at the first preset speed, the vehicle engine is stopped (turned off) and the vehicle coasts, thereby producing vehicle deceleration. When the control system further detects that the actual vehicle speed of the coasting vehicle reaches a second preset speed which is less than the desired traveling speed, the vehicle engine is started and acceleration is again initiated. The acceleration-deceleration operation is continuously repeated resulting in an average vehicle speed which equals the desired vehicle traveling speed. | 5 |
This is a continuation of application Ser. No. 09/285,499 filed Apr. 1, 1999, now abandoned, the entire content of which is hereby incorporated by reference in this application.
This invention was made with Government support under Contract No. DE-FC21-95MC31176 awarded by the Department of Energy. The Government has certain rights in this invention.
TECHNICAL FIELD
This invention relates to a cooling air circuit for a gas turbine bucket tip shroud.
BACKGROUND OF THE INVENTION
Gas turbine buckets have airfoil shaped body portions connected at radially inner ends to root portions and at radially outer ends to tip portions. Some buckets incorporate shrouds at the radially outermost tip, and which cooperate with like shrouds on adjacent buckets to prevent hot gas leakage past the tips and to reduce vibration. The tip shrouds are subject to creep damage, however, due to the combination of high temperature and centrifugally induced bending stresses. In U.S. Pat. No. 5,482,435, there is described a concept for cooling the shroud of a gas turbine bucket, but the cooling design relies on air dedicated to cooling the shroud. Other cooling arrangements for bucket airfoils or fixed nozzle vanes are disclosed in U.S. Pat. Nos. 5,480,281; 5,391,052 and 5,350,277.
BRIEF SUMMARY OF THE INVENTION
This invention utilizes spent cooling air exhausted from the airfoil itself for cooling the associated tip shroud of the bucket. Specifically, the invention seeks to reduce the likelihood of gas turbine tip shroud creep damage while minimizing the cooling flow required for the bucket airfoil and shroud. Thus, the invention proposes the use of air already used for cooling the bucket airfoil, but still at a lower temperature than the gas in the turbine flowpath, for cooing the tip shroud.
In one exemplary embodiment of the invention, leading and trailing groups of cooling holes extend radially outwardly within the airfoil generally along respective leading and trailing edges of the airfoil. Each group of holes communicates with a respective cavity or plenum in the radially outermost portion of the airfoil. Spent cooling air from the radial cooling passages flows into the pair of plenums and then through holes in the tip shroud and exhausted into the hot gas path. These latter holes can extend within the plane of the tip shroud and open along the peripheral edges of the shroud, or at an angle so as to open through the top surface of the shroud.
In a second exemplary embodiment, relatively small film cooling holes are drilled through the radial plenum walls on both the pressure and suction side of the airfoil. These holes open on the underside of the shroud, in the area of the shroud fillets. In a variation of this arrangement, the leading and trailing plenums as described above are connected by an internal connector cavity. Preferably, the majority of the cooling holes open along the pressure and suction side in the leading edge area of the blade, with fewer holes opening in the trailing edge area. Covers are joined to the shroud to close the plenums and one or more metering holes are drilled in the respective covers in order to control the cooling air exhaust.
In a third exemplary embodiment, the individual radial cooling holes within the airfoil are drilled slightly oversize at the tip shroud end. In other words, each cooling hole may be considered to have its own plenum or chamber. Plugs or inserts are joined to the holes to seal the ends of the latter, while shroud cooling holes are drilled directly into the individual plenums and exit either at the top of the shroud or along the underside of the shroud. A metering hole may be required in the various radial cooling hole plugs to insure proper flow distribution.
In its broader aspects, the invention relates to an open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit comprising a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud.
In another aspect, the invention relates to an open cooling circuit for a gas turbine airfoil and associated tip shroud comprising a plurality of cooling holes internal to the airfoil and extending in a radially outward direction; a first plenum chamber in an outer radial portion of the airfoil, each of the plurality of holes communicating with the plenum; additional cooling holes in the tip shroud, communicating with the plenum, and exiting through the tip shroud.
In still another aspect, the invention relates to a method of cooling a gas turbine airfoil and associated tip shroud comprising a) providing radial holes in the airfoil and supplying cooling air to the radial holes; b) channeling the cooling air to a plenum in the airfoil; and c) passing the cooling air from the plenum and through the tip shroud.
Additional objects and advantages of the invention will become apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side section illustrating the turbine section of a land based gas turbine;
FIG. 2 is a partial side elevation, in generally schematic form, illustrating groups of radial cooling passages in a turbine blade and tip shroud in accordance with a first exemplary embodiment of the invention;
FIG. 3 is a top plan view of a tip shroud in accordance with the first embodiment of the invention;
FIG. 4 is a top plan view showing an alternative to the arrangement shown in FIG. 3;
FIG. 5 is a top plan view of a turbine airfoil and tip shroud in accordance with a second exemplary embodiment of the invention;
FIG. 6 is a section taken along the line A—A of FIG. 5;
FIG. 7 is a top plan of an airfoil and tip shroud similar to FIG. 5, but illustrating a connector cavity between the interior plenums;
FIG. 8 is a top plan view of a tip shroud in accordance with a third exemplary embodiment of the invention, illustrating shroud cooling holes opening on the top surface of the tip shroud;
FIG. 9 is a top plan view of the tip shroud shown in FIG. 8, but illustrating the shroud cooling holes which open along the bottom surface of the tip shroud;
FIG. 10 is a section taken along the line 10 — 10 of FIG. 8; and
FIG. 11 is a section taken along the line 11 — 11 of FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, the turbine section 10 of a gas turbine is partially illustrated. The turbine section 10 of the gas turbine is downstream of the turbine combustor 11 and includes a rotor, generally designated R, with four successive stages comprising turbine wheels 12 , 14 , 16 and 18 mounted to and forming part of the rotor shaft assembly for rotation therewith. Each wheel carries a row of buckets B 1 , B 2 , B 3 and B 4 , the blades of which project radially outwardly into the hot combustion gas path of the turbine. The buckets are arranged alternately between fixed nozzles N 1 , N 2 , N 3 and N 4 . Alternatively, between the turbine wheels from forward to aft are spacers 20 , 22 and 24 , each located radially inwardly of a respective nozzle. It will be appreciated that the wheels and spacers are secured to one another by a plurality of circumferentially spaced axially extending bolts 26 (one shown), as in conventional gas turbine construction.
Turning now to FIGS. 2 and 3, a turbine bucket includes a blade or airfoil portion 30 and an associated radially outer tip shroud 32 . The airfoil 30 has a first set of internal radially extending cooling holes generally designated 34 , and a second set of five radially extending cooling holes 36 . The first set of cooling holes 34 is located in the forward half of the airfoil, closer to the leading edge 38 , whereas the second set of holes 36 is located toward the rearward or trailing edge 40 of the airfoil. The first set of leading edge cooling holes 34 open to a first cavity or plenum 42 at the radially outermost portion of the airfoil, while trailing edge cooling holes 36 open into a second plenum 44 closer to the trailing edge 40 of the airfoil. The plenums 42 and 44 are shaped to conform generally with the shape of the airfoil, and extend radially into the tip shroud 32 . The plenums are sealed by recessed covers such as those shown at 46 , 48 , respectively, in FIG. 4 . The covers may have metering holes 50 , 52 for controlling the exhaust rate of the cooling air into the hot gas path.
In addition, the plenums 42 and 44 can exhaust directly through cooling passages internal to the tip shroud. For example, as shown in FIG. 3, spent cooling air from chamber 42 can exhaust through the edges of the tip shroud via passages 54 , 56 and 58 which lie in the plane of the shroud 32 and which distribute cooling air within the shroud itself, thus film cooling and convection cooling the shroud. Similarly, plenum 44 communicates with a similar passage 60 in the trailing edge portion of the shroud 32 .
It will be appreciated that the number and diameter of radial holes in the airfoil will depend on the design requirements and manufacturing process capability. Thus, FIG. 2 shows groups 34 , 36 of four and three radial holes respectively, whereas FIG. 3 shows both groups to have five radial holes each.
In FIG. 4, a variation of this embodiment has cooling holes 62 , 64 , 66 , 68 , 70 and 72 in the tip shroud, in communication with the leading plenum 42 , but angled relative to the plane of the tip shroud so that they exhaust through the top surface 74 of the tip shroud, rather than at the shroud edge. Similarly, cooling holes 76 , 78 and 80 in communication with the trailing plenum 44 also exhaust through the top surface 74 of the shroud.
FIGS. 5 and 6 illustrate a second embodiment of the invention, and, for convenience, reference numerals similar to those used in FIGS. 2 and 3 are used in FIG. 4 where applicable to designate corresponding components, but with the prefix “1” added. Thus, a first set of radially extending internal cooling holes 134 extends radially outwardly through the airfoil, closer to the leading edge 138 of the airfoil, opening at plenum 142 . A similar second set of cooling holes 136 extends radially outwardly within the airfoil, closer to the trailing edge 140 of the airfoil, opening into plenum 144 . A first group of shroud cooling holes 162 , 164 , 166 and 168 , 170 , 172 and 174 extend from both the pressure and suction sides, respectively, of the plenum 142 to provide film and convection cooling of the underside of the tip shroud 132 , with the cooling holes exiting the airfoil in the area of the tip shroud fillet 82 . A second group of shroud cooling holes 176 , 178 extend from plenum 144 and open on pressure and suction sides, respectively of the airfoil, again on the underside of the tip shroud. As in the previous embodiment, flow may also be metered out of the plenum covers 146 , 148 by means of one or more metering holes 150 (FIG. 7 ). The number of shroud cooling holes exiting on the pressure and suction sides of the shroud may vary as required.
FIG. 7 is similar to FIG. 5 but includes a connector cavity 84 extending internally between the leading and trailing plenums 142 , 144 , respectively. Cooling holes from the plenums exhaust about the tip shroud undersurface as described above. The connector cavity 84 results in most cooling air flowing to the leading edge plenum 142 to exit via cooling holes 162 , 164 , 166 and 168 , 170 , 172 and 174 arranged primarily along the pressure and suction sides, respectively, of the airfoil in the leading edge region thereof. As in FIG. 6, only two of the cooling holes 176 , 178 exit in the trailing edge area of the airfoil. This arrangement desirably channels most of the cooling air to the leading edge region of the airfoil, to be washed back across the trailing edge region by the hot combustion gas, thereby providing desirable cooling of the shroud. The metering hole 150 in the cover 146 exhausts all of the spent cooling air which is not otherwise used for direct tip shroud cooling along the undersurface thereof, and dilutes the hot gas flowing over the top of the shroud.
FIGS. 8-11 illustrate a third embodiment of the invention, and, for convenience, reference numerals similar to those used to describe the earlier embodiments are used in FIGS. 8-11 where applicable to designate corresponding components, but with the prefix “2” added. A first set of radially extending internal cooling holes 234 extends radially outwardly through the airfoil, closer to the leading edge 238 of the airfoil. A second set of internal cooling holes extends radially outwardly within the airfoil, closer to the trailing edge 240 of the airfoil. Each individual radial cooling hole 234 is drilled or counterbored at its radially outer end to define an individual plenum 242 , while each radial cooling hole 236 is similarly drilled or counterbored to form a similar but smaller plenum 244 . Each enlarged chamber or plenum 242 , 244 is sealed by a plug or cover 246 (in FIGS. 8 and 9, the plugs or covers 246 are omitted for purposes of clarity). Each plug or cover may be provided with a metering hole 250 to insure proper flow distribution.
A first group of shroud film cooling holes 262 , 264 , 266 , 268 , 270 , and 272 extend from the various plenums 242 through the tip shroud and open along the top surface of the tip shroud. Similarly, a second group of film cooling holes 274 , 276 , and 278 extend from the plenums 244 and also open along the top surface of the tip shroud. Note that film cooling holes 264 and 262 extend from the same plenum, while film cooling holes 270 and 272 extend from the next adjacent plenum. The arrangement may vary, however, depending on particular applications.
FIG. 9 illustrates film cooling holes extending from the plenums 242 and 244 , but which open along the underside of the tip shroud, generally along the tip shroud fillet 282 . Thus, film cooling holes 284 , 286 , 288 , and 290 extend from two of the plenums 242 and open on the underside of the tip shroud, on both pressure and suction sides of the airfoil. Note that film cooling holes 284 and 290 extend from the same plenum, while a similar arrangement exists with respect to shroud film cooling holes 286 and 288 which extend from the adjacent plenum.
Shroud film cooling holes 294 and 296 extend from a pair of adjacent plenums 244 associated with radial cooling holes 236 on the opposite side of the tip shroud seal, also along the underside of the tip shroud.
These arrangements are intended to reduce the likelihood of gas turbine shroud creep damage while minimizing the cooling flow required for the bucket, while more efficiently utilizing spent airfoil cooling air to also cool the tip shroud.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | An open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit including a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority in U.S. Provisional Patent Application Ser. No. 61/448,997, filed Mar. 3, 2011, and is related to AUTOMATED BIOMETRIC IDENTIFICATION SYSTEM (ABIS) AND METHOD, U.S. patent application Ser. No. 13/412,512, filed Mar. 5, 2012, which claims priority in U.S. Provisional Patent Application Ser. No. 61/448,972, filed Mar. 3, 2011, and is also related to AUTOMATED BIOMETRIC SUBMISSION AND IMPROVED SCANNING SYSTEM AND METHOD, U.S. patent application Ser. No. 13/095,601, filed Apr. 27, 2011, which claims priority in U.S. Provisional Patent Application Ser. No. 61/328,305, filed Apr. 27, 2010, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present disclosed technology relates generally to a system and method for recording, uploading, and utilizing video recorded in real-time, and specifically to a front-end and back-end video archival system and method using video recorded in real-time to aid in emergency or weather response.
2. Description of the Related Art
Digitally watermarking or embedding data into recorded video is well known in the art. Modern mobile phones, digital cameras, and other mobile devices are capable of recording video anywhere a user is located, and uploading that video to common video archive websites, such as youtube.com. These mobile devices may also include GPS functionality, allowing the video to be tagged with location data and other relevant data so that anyone who ultimately views the video can determine where and when a video was taken.
Presently, such mobile user-submitted videos may be uploaded to video archival or video sharing networks, but the value of the embedded video data is typically underused. For instance, a video may be uploaded to a publicly available video archive database where numerous end users are able to view the video, but the video may not be used immediately and the relevance of the time and location of the video that has been uploaded loses value.
Typical video archive databases either include embedded video data as an afterthought, or limit the access of that data to selected users. One such example of selective use of video data is U.S. Pat. No. 7,633,914 to Shaffer et al. (the “914 Patent). Although video data may be uploaded and used for assessing critical security or other means in the geographic area of the video data, the '914 Patent relies on users who have already accessed “virtual talk groups” to upload relevant video data. That video data is then only immediately accessible to members of the same virtual talk groups, which limits the effectiveness of the video data to a small number of users.
Embedded video or photograph data is also used by police departments for accurate evidence collection. U.S. Pat. No. 7,487,112 to Barnes, Jr. (the “112 Patent”) describes this ability, but limits the use of the uploaded video or photographic data to the police department. Video or photographic data uploaded to the collection server is stored and not immediately used in any capacity. Such a technique merely simplifies the tasks of a police officer during evidence collection and does not fully embrace the value of embedded video data.
What is needed is a system which provides mobile users the ability to record video with embedded data, upload that video to a commonly accessible database where the video may be immediately reviewed, and any particular value that can be gathered from the uploaded video be submitted to emergency crews or other relevant parties for immediate review of the recently uploaded video. Heretofore there has not been a video archival system or method with the capabilities of the invention presented herein.
SUMMARY OF THE INVENTION
Disclosed herein in an exemplary embodiment is a system and method for uploading and archiving video recordings, including a front-end and a back-end application.
The preferred embodiment of the present invention includes a front-end application wherein video is recorded using a mobile device. The recorded video is embedded with date, time and GPS location data.
The video is stored on an online back-end database which catalogues the video according to the embedded data elements. The video may be selectively reviewed by relevant experts or emergency personnel for immediate response to the uploaded video and/or distribution to the proper parties. The video may also be archived for later review and use by any number of end-users.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments of the disclosed subject matter illustrating various objects and features thereof, wherein like references are generally numbered alike in the several views.
FIG. 1 is a block diagram showing the relationship between the various elements of the preferred embodiment of the present invention.
FIG. 2 is a flowchart showing the practice of a method of the preferred embodiment of the present invention.
FIG. 3 is a diagram illustrative of a user interface for viewing videos on a computer utilizing the preferred embodiment of the present invention.
FIG. 4 is a diagram illustrative of a user interface for viewing archived video associated with the preferred embodiment of the present invention.
FIG. 5 is a block diagram showing the relationship between various elements of an alternative embodiment of the present invention.
FIG. 6 is a flowchart showing the practice of a method of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction and Environment
As required, detailed aspects of the disclosed subject matter are disclosed herein; however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, a personal computer including a display device for viewing a typical web browser or user interface will be commonly referred to throughout the following description. The type of computer, display, or user interface may vary when practicing an embodiment of the present invention.
A preferred embodiment of the present invention relies on a front-end mobile application 3 associated with a mobile personal computing device 7 , such as a mobile phone, personal digital assistant, or other hand-held computing-capable device. The mobile personal computing device 7 must access a wireless network 16 . A back-end mobile application 17 may be accessed via any personal computing device with capable access to a network, such as the World Wide Web.
II. Geo-Location Video Archive System and Method
Referring to the drawings in more detail, reference numeral 2 generally refers to a geo-location video archive system, comprising a front-end mobile application 3 , a back-end mobile application 17 , and an end user 30 .
FIG. 1 demonstrates the relationship between the front-end application 3 , the back-end application 17 , a wireless network 16 , and an end user 30 . The front-end application 3 is comprised of a mobile device 7 . This mobile device 7 may be any hand held mobile device capable of recording and uploading video data via the wireless network 16 to a database server 18 utilized by the back-end application 17 .
The mobile device 7 includes a camera 4 or other video capture ability capable of recording either still or video images, an antenna 6 , a processor 8 , a wireless network connection 10 , a memory 12 storing an application 14 , and a position reference 13 .
The antenna 6 is capable of receiving and transmitting data over a wireless network 16 , such as image data recorded by the camera 4 . The processor 8 is adapted for processing all data required by the mobile device. The wireless network connection 10 allows the mobile device 7 to access the wireless network 16 for transmission and reception of data. The memory 12 stores all data necessary for the function of the mobile device 7 , including image data recorded by the camera 4 . An application 14 for accessing the back-end mobile application 17 via the wireless network 16 is stored on the memory. The position reference 13 includes optional two-dimensional or three-dimensional positional information about the mobile device 7 . This positional reference 13 may optionally be attached to image data recorded with the camera 4 .
The primary purpose of the mobile application 7 is to capture high resolution video by use of the mobile device's 7 camera 4 . The application 14 will collect video in one to ten second slices and transmit it with related data. This data may include Global Positioning System (GPS) location in the form of Longitude and Latitude, Date and Time stamp, description of up to 140 characters, as well as declination based upon magnetic or true north that will be packaged in an XML-formatted file with the phone's ID and a user name. Combined with the video slice, the mobile application will send a “packet” 19 to the database server 18 .
The back-end mobile application 17 is comprised of a database server 18 which serves to receive all data submitted by mobile devices 7 included in the front-end application 3 , and an optional subject matter expert (expert) 29 capable of reviewing submitted data for real-time use and organized archiving.
The database server 18 further includes an archive database 20 , a memory 22 , a processor 24 , a video review station application 26 and a user web application 28 . Image data and other data submitted to the database server 18 via the front-end mobile application 3 are stored in the archive database 20 . The video review station application 26 is an optional feature that may be included for use by the expert 29 for reviewing submitted image data and other submitted data. The user web application 28 is an optional feature allowing end users 30 to access data uploaded to the database 18 for personal use.
Multiple mobile devices 7 may be incorporated with the front-end mobile application 7 . Each front-end application may upload recorded data simultaneously to the database server 18 . The database server 18 will receive a transmission packet 19 from various mobile devices 7 . If this is a new transmission, the video slice and the metadata will be split from the transmission packet and saved into a storage folder located in the archive database 20 . If the packet is a continuation of a current transmission, the video slice will be unpackaged from the packet, and merged with the previously received video slice. In addition the metadata transmitted with the packet will be merged with the current metadata XML. If this is the terminating packet, the video slice will be unpackaged from the packet, and merged with the previously received video slice. In addition, the metadata transmitted with the packet will be merged with the current metadata XML. Once complete, the video file and metadata will be saved into the archive database 20 . Finally, a confirmation 27 of the received video can be sent to the mobile device 7 , confirming that the video transmission was complete. In turn, this information may be made available to another application, web site, or other end user 30 for whatever needs it may have.
III. Database Video Upload, Review, and Use
In an embodiment of the present invention, an expert 29 will review video files uploaded to the database server 18 through the video review station application 26 . The video review station application 26 will collect video from the front-end application 3 . The application will gather the videos corresponding XML metadata and display the information for the expert 29 . This will include items such as date, time, location, and video length. The expert 29 will then tag the event as a category that best describes the video (i.e. tornado, flood, thunder storm), apply search keywords, and modify the description as needed. The expert 29 will then, using a set of defined standards, grade the video, such as on a rating of one to five “stars.” As examples, five stars may indicate: the highest quality video; video of devastating weather; or video meeting predefined quality definitions. At this time the video can be rejected if it does not meet video submission related requirements. Once this process has been completed, the expert 29 will save the video and corresponding XML to the proper database tables, making it available for searching.
FIG. 2 demonstrates the practice of the above method in more detail. This will start at 31 when a phenomenon or event occurs at 32 . A mobile user will use their mobile device to capture video of the event at 34 and will upload that video to the database server at 36 . As explained above, the video will be uploaded in slices and will be saved to the archive database at 38 for further review.
The database will check for raw video submissions at 40 and will determine if a new video has been uploaded or submitted to the server at 42 . If no new video data has been uploaded or submitted, the process continues checking the database for new submissions.
Upon detecting a new video submission, the video will be transferred to the expert for review at 44 . The expert checks to determine if the video meets the back-end application requirements at 46 . These requirements may include video relevance, video quality, and whether similar videos have already been uploaded for a single event. If the video does not meet all requirements, the video is marked as “rejected” at 48 , saved into a non-searchable database table at 50 , and stored in the video archive database at 38 .
If the expert determines that the video meets all requirements, the expert will then grade the video based on standard operating procedures at 52 . The video will be categorized at 54 to allow for easy searching of the video through the user web application. Categories may include video location, event description, or other defining terms that will allow end users to easily search for and find the relevant video. Searchable keywords are also added to the video at 56 , which will simplify the video search that will return the particular video being reviewed. The video description will be modified at 58 , if needed. This may be performed if, for example, the mobile user who uploaded the video incorrectly described the video in question. Finally, the video will be saved to searchable database tables at 60 and stored in the video archive database at 38 .
IV. Video Archive Service User Software
FIGS. 3 and 4 show the typical interface an end user 30 may see when accessing the user web application 28 . The user web application 28 allows all end users 30 to have access to all reviewed and archived videos available.
In the preferred embodiment, the interface is accessed through a personal computer via the World Wide Web or some other accessible network. FIG. 3 shows a window 61 will be accessed by the end user 30 . The window 61 includes a video playback 62 including a video title 64 , a play/pause button 66 , a play-back progress bar 68 and a progress slider 70 .
Additional data uploaded along with the video data may be included in the window 61 . This data may include location information about the video, such as longitude 72 , latitude 74 , city 76 , state 78 , and country 80 . Additionally, date 82 , time 84 , and device ID data 86 may be uploaded and stored, embedded within the video data at the time the video was captured. Each of these terms will allow users to find applicable videos relating to what they are searching.
A description 88 of the video, which may be written by the original mobile user or by the expert 29 , is included in the window, along with a series of search keywords 90 assigned by the expert 29 . The end user 30 has the option of saving the video which results from the user's search at 92 . The video may be stored locally on the end user's machine, or could be stored to the end user's profile so that the user may later return to the searched video. The end user 30 may also perform a new search 94 , including previous search terms with new terms added, or the user may clear the search 96 and start a completely new search.
FIG. 4 shows an alternative search window 61 . Here, the end user 30 is capable of viewing the entire archived database list 100 . In the example shown by FIG. 4 , the video archive list 100 organizes the video by date and category, allowing the end user 30 to browse through all videos uploaded and saved to the database.
Along with the video playback 62 , video title 62 , play/pause button 66 , play-back progress bar 68 and progress slider 70 , the window 61 includes a user video rating 98 . This rating may be assigned by the expert 29 or by end users 30 who visit the site, view the video, and rate the video. The rating will allow future users to determine if there may be a better video to watch, depending on what they may be looking for.
V. Weather Video Archive Application
In one embodiment of the present invention, the video uploaded to the database 20 relates to current weather occurring somewhere in the world. The mobile user records video of real-time weather activity with a mobile device 7 , uploads this weather video to the database server 18 where it is reviewed by an expert 29 , and the weather video is placed into the archive database 20 where it may be reviewed by end users 30 through the user web application 28 . This allows end users to view an up-to-date weather video of any location where mobile users are uploading video from, including in the end user's immediate vicinity.
The primary section of interest of the user web application 28 will likely be an interactive map display showing various locations of un-archived video and current weather radar overlays. The user will have the ability to select the grade of video that is displayed on the map. Notifications of videos relating to specific locations will appear on the map as an overlay to indicate the location the video was captured. Hovering over the notifications will allow a brief time lapsed preview of the accompanying video. Activating the notifications will display the full video in a window 61 . At this point the user will have the ability to download the full video, copy link information to embed in a web site, or other video functionality.
VI. 911-V Alternative Embodiment
An alternative embodiment video upload and archive system 102 encompasses the use of a back-end application 117 that will take video collected from a front-end mobile application 103 , determine its location via longitude and latitude, and upload that information to a 911V system server 118 . If the location where the video has been recorded is within a current 911V application 128 site software installation, the video is automatically routed to the appropriate emergency authority 123 . If the location corresponds to a 911V application 128 site participant, the video is automatically submitted to that 911V emergency authority 123 with the location where the video was recorded. This will allow the site to immediately dispatch emergency services as needed based upon what is shown on the video.
If the location is not a participant in 911V, a call center specialist 129 contacts the appropriate public safety answer point (PSAP) 130 jurisdiction, based upon the actual location determined by the longitude and latitude embedded in the submitted video. The call center specialist 129 will have the ability to email the video submitted to the 911V system 118 to the PSAP 130 for review. All 911 or 911V contact information will be saved to the videos corresponding XML metadata, for future audits and investigations if needed.
FIG. 5 is a block diagram showing the interaction between the elements of the front-end mobile application 103 and the back-end mobile application 117 . The front-end application 103 is comprised of a mobile device 107 including a camera 104 or other image recording device, an antenna 106 , a processor 108 , a wireless network connection 110 , memory 112 including a stored application 114 , and a position reference 113 . As in the preferred embodiment, the mobile device 107 records an event with the camera 104 and transmits video data via packets 119 through a wireless network 116 to the back-end mobile application 117 . Position reference 113 is necessarily included with the uploaded video packet 119 to determine where the recorded emergency is occurring and to contact the correct authorities.
The back-end mobile application 117 is comprised of a 911V system server 118 and call center specialist 129 . The server 118 further includes an archive database 120 , memory 122 , a processor 124 , a video review station application 126 , a notification method 127 , and the 911V application 128 . The call center specialist 129 may review incoming video data and direct the video to the nearest PSAP 130 , or the 911V application 128 will determine the location of the uploaded video data, determine the proper notification method 127 , and automatically forward it to the nearest 911V emergency authority 123 .
FIG. 6 demonstrates the practice of a method of the alternative embodiment. The method starts at 131 with an emergency phenomenon or event occurring at 132 . A mobile user possessing a mobile device capable of recording and uploading video data captures the video data of the emergency at 134 and uploads it to the 911V web service at 136 . Video slices are stored in the video archive database at 138 as they are uploaded, and the system database checks for newly submitted raw video data at 140 . If no new video is submitted between checks at 142 , the process repeats until new video is detected.
Once new video is detected at 142 , the system determines the location of the video by longitude and latitude at 144 . The system determines whether the location of the uploaded video is a 911V site at 146 .
If the site where the video was recorded is located in a 911V site, the video is transferred to the PSAP at 148 and archived as “received and transferred” at 150 and stored in the video archived database at 138 .
If, however, the location where the video was recorded is not a 911V site, the call center specialist or the system itself will determine the appropriate PSAP jurisdiction to handle the reported emergency at 152 . The proper PSAP is contacted at 154 and the emergency is reported at 156 , including recording the call at 158 and adding contact documentation to the existing XML data at 160 . All of this data is saved to the database at 162 and stored in the video archive database at 138 .
It will be appreciated that the geo-location video archive system can be used for various other applications. Moreover, the geo-location video archive system can be compiled of additional elements or alternative elements to those mentioned herein, while returning similar results.
It is to be understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects. | A system and method for recording, uploading, and archiving video recordings, including a front-end and a back-end application. The preferred embodiment of the present invention includes a front-end application wherein video is recorded using a mobile device. The recorded video is embedded with date, time and GPS location data. The video is stored on an online back-end database which catalogs the video according to the embedded data elements. The video may be selectively reviewed by relevant experts or emergency personnel for immediate response to the uploaded video and/or distribution to the proper parties. The video may also be archived for later review and use by any number of end-users. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Continuation-In-Part application claims priority from applicants' Non-Provisional application Ser. No. 13/050,927, filed on Mar. 17, 2011, which claimed priority from applicants' Provisional Patent Application No. 61/390,140 filed on Oct. 5, 2010.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
DESCRIPTION OF ATTACHED APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention relates to an apparatus, method and system for a human individual to exercise his body in a novel manner wherein the user, when he is in the prone position, is able to move one or both of his arms, while holding the instant apparatus placed on a relatively flat surface, in all three planes of human motion simultaneously; i.e. saggital, frontal and transverse planes.
[0005] In the prior art, a plethora of devices have focused on prone position exercise devices; i.e. push-up assist devices that allowed users a greater range of vertical motion by lifting the users hands some distance off of the ground on a stable surface, while other devices made some further improvements by further allowing only arm rotation or twisting, while the user was doing a push up with the aforesaid devices, said improved device being limited by being stationary or immobile on a flat surface, and only permitting the user to twist said user's arm's while doing a push-up, positioning as disclosed in Hauser, Friedman, Mills series of patents, U.S. Pat. No. 7,238,147, U.S. Pat. No. 7,468,025, U.S. Pat. No. 7,553,267, D579503, D597153, D599417; i.e. the device itself was fixed to the floor or flat surface by the weight of the user and friction, unable to slide across the flat surface in any direction, simultaneously while the user was holding the device in his hands.
[0006] While these devices fulfill their respective, particular objective and requirements, the aforementioned patents did not describe an upper body exercise and physical conditioning device that is described herein by the instant application. This instant invention allows a user to move his arms in a novel manner, i.e. the user can position his hands on the device (in any manner) and then move his arms in all three planes of human motion (saggital, frontal and transverse planes), whether in one plane, or more than one plane at the same time, while the device is free to slide in an infinite number of directions while placed on the floor, and while the user is bodily in the prone position. This permits the exercise of numerous additional groups of muscle groups compared to that of the prior art. The instant invention also the exercise of, and the resultant improvement in, a user's upper body's joints ranges of motion, thereby improving the user's joint flexibility. In addition, the invention's structural geometric arrangement allows for rigid, secure and yet a simple and lightweight design. The instant application improves upon the prior art, with an apparatus, method and system that allows for user's arms to move in the saggital, frontal and transverse planes of human motion simultaneously. None of the prior art has allowed for this broad range of exercise versatility in a single device. Some of the muscle groups that may be exercised by this novel device include, but are not limited to, pectoral major, pectoral minor, abdominals, triceps, and deltoids. The instant invention further allows for arm flexion, extension, internal and external rotation, adduction and abduction. The prior art was not capable of exercising as many muscles, joints and ranges of human motion, at one time, with a single system.
[0007] Further, the devices in the prior art generally had more moving parts than the instant invention, which made them more difficult and expensive to manufacture and would increase their chances for failure. The applicant's instant invention solves all of these aforesaid problems and limitations in the prior art by fabricating the device with strong, resilient and flexible materials, including, but not limited to injection molded plastics, and using high hertz contact strength bearing configurations at the interface of stationary (base) and moving parts (spherical rolling balls one in each recess in said non-rolling base), said bearings being either friction bearings wherein the stationary base surface and/or the rolling spherical balls which move relative to one another comprise self-lubricating composite materials, or said bearings being configured as an anti-friction type wherein the sliding friction between the stationary base and the rotating ball surfaces is replaced with primarily rolling friction (although some sliding friction may exist) by placing a plurality of cylindrical or spherical rollers with axles mounted in cradles in the recesses in the stationary base and said rollers contacting with point or line contact, and rolling with spherical ball in each recess in the base. One of said solid bearing materials being fabricated of halogen-hydrocarbon-polymers. This new design is structurally simpler than the prior art, thereby making it easier to use, and substantially more simple and less costly to manufacture and maintain. Therefore, the applicant's instant invention solves these aforesaid problems and limitations. It can be appreciated that there exists a continuing need for a upper body exercise apparatus, method and system, which serves to exercise the largest grouping of human body muscle groups, than any other apparatus, method or system disclosed in the prior art. In this regard, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
[0008] In the view of the above stated disadvantages inherent in the known types of devices now present in the prior art, the present invention provides an improved upper body exercise device. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new unique upper body exercise device which has all the advantages of the prior art and none of the disadvantages.
[0009] To attain this, the present invention comprises an apparatus, method and system that has a means for a user to grasp said apparatus with his hands (one identical device in each of user's hands, or in the alternate the user may choose to grasp only one device with one or both of his hands), then since the apparatus has a means for sliding across the flat surface it is resting on (said means comprising a plurality of spherically shaped balls suitably retained within the base of said apparatus), in any direction simultaneously, with little or no friction, the user then has the option to move his arms together or alternately forward and back in the human saggital plane, and/or laterally in the human frontal plane, and/or through arm sweep rotation motions about a user's shoulders in the human transverse plane, or in any possible combination of these aforesaid human motions; thereby rendering the user able to exercise his muscles and joints in an infinite number of directions, to exercise several muscle groups and joints simultaneously. This improves the user's strength and joint range of motion.
[0010] There has thus been outlined, rather broadly, the more important features of this invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter.
[0011] In this respect, before explaining the disclosed embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0012] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the limited claims herein be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0013] It is therefore an object of the present invention to provide a novel unique upper body exercise apparatus, method and system which has all the advantages of the prior art upper body exercise devices and none of the disadvantages.
[0014] It is another object of the present invention to provide a novel unique upper body exercise device which may be more easily and more efficiently manufactured and marketed than the prior art.
[0015] It is a further object of the present invention to provide a novel unique upper body exercise device which is fabricated of durable and reliable materials, simpler design and less costly to manufacture and maintain.
[0016] An even further object of the present invention is to provide a novel unique upper body exercise device which is susceptible of an even lower cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such a device even more economically available to the buying public, yet with greater capabilities than that disclosed in the prior art.
[0017] Even still another object of the present invention is to provide a novel unique upper body exercise device for allowing a person to move their arms while grasping the apparatus, in all three planes of human motion (saggital, frontal and transverse) simultaneously, and in any degree of each of these three planes, that the user so desires, to achieve the specific results that a particular user wants and needs.
[0018] For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
[0020] In the drawings:
[0021] FIG. 1 is an elevation view of the preferred embodiment of the upper body exercise device constructed in accordance with the principles of the present invention.
[0022] FIG. 2 is a plan view of one preferred embodiment of the upper body exercise device constructed in accordance with the principles of the present invention.
[0023] FIG. 3 is a plan view of another preferred embodiment of the upper body exercise device constructed in accordance with the principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] With reference now to FIG. 1 , FIG. 2 and FIG. 3 , are the preferred embodiments of the upper body exercise device embodying the principles and concepts of the present invention.
[0025] In the preferred embodiment of FIG. 1 and FIG. 2 , the device has a generally circular configuration base ( 100 ), in which there is a minimum of three, but in this case four spherically shaped balls ( 101 ) placed in half spherically or cylindrically shaped recesses (one recess for each rolling ball) within the base ( 100 ), the balls ( 101 ) being held within the base ( 100 ) by suitable means [said means comprising circular shaped retaining clips, a cover plate over the entire bottom of the base with holes cut for the rolling balls, or the recess having a reduced diameter interference fit at the very bottom of the base ( 102 )]. In the preferred embodiment of FIG. 1 and FIG. 3 , the device has a generally rectangular configuration non-rolling base ( 100 ), in which there is a minimum of three, but in this case four spherically shaped rollers ( 101 ) placed in half spherically or cylindrically shaped recesses within the base ( 100 ), the spherically shaped balls ( 101 ) being held within the base ( 100 ) by suitable means [said means comprising circular shaped retaining clips, a cover plate over the entire bottom of the base with holes cut for the rolling balls, or the recess having a reduced diameter interference fit at the very bottom of the base ( 102 )]. The aforesaid rolling ball retention means prevent the spherically shaped balls from dropping out of the device's base if the device is lifted off of the floor by the user. In the preferred embodiments the user grabs the two identical devices, one in each of his two hands using a grab bar ( 103 ), said grab bar being mounted in, and supported by the two side support side plates ( 104 ). Optionally, there may be a user brake bar ( 105 ) mounted on the grab bar ( 103 ), wherein the user may optionally grab and then squeeze the brake bar to increase the resistance for the aforesaid spherical balls from freely rolling, thereby giving the user greater control of his own exercise mobility and resistance training. At the interface of the spherical balls ( 101 ) and the spherical or cylindrical recesses placed in the base ( 100 ) for said balls ( 101 ), is a high hertz contact stress capable friction or anti-friction type bearing surfaces ( 106 ), said bearings being either friction bearings wherein the stationary base surface and/or the rolling spherical balls which move relative to one another comprise self-lubricating composite materials, or said bearings being configured as an anti-friction type wherein the sliding friction between the stationary base and the rotating ball surfaces is replaced with primarily rolling friction (although some sliding friction may exist) by placing a plurality of cylindrical or spherical bearing rollers being mounted in cradles in the recesses in the stationary base and said rollers contacting with point or line contact, and rolling with spherical ball in each recess in the base ( 106 ). Optionally, said apparatus has access holes ( 107 ) at the bottom of the recesses traversing through the base to facilitate removal of the spherical balls and to facilitate cleaning and maintenance of the apparatus.
[0026] Not illustrated in the drawing, is a brake pad type mechanism suitably linked to the brake bar ( 105 ), which applies adjustable braking load, as applied by the user squeezing the brake bar ( 105 ). Said brake bar components being configured to allow the user to personally adjust the rate at which the spherical balls may roll in any or all of the three directions of human motion; i.e. saggital, frontal and/or transverse.
[0027] While the present invention has been particularly described, in conjunction with preferred embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. For one example, the spherical rollers may be replaced by a combination system that provides for the same freedom of three dimensional motions that the spherical rollers provide; i.e. cylindrical rollers not mounted directly on base plate ( 100 ), but rather said four rollers each being mounted on a four fully rotational discs, with said discs then being mounted on the bottom of the base plate ( 100 ). It is therefore contemplated that the instant disclosure will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.
[0028] In so far as the description above and the accompanying drawing disclose any additional subject matter that is not within the scope of the limited claims below, the inventions are not dedicated to the public and the right to file one or more applications to claim such additional inventions is reserved.
[0029] While the invention has been described in connection with a preferred embodiments, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention. | The present invention relates to an apparatus, method and system for a human individual to exercise his body in a novel manner wherein the user, when he is in the prone position, is able to move his arms, while holding the instant apparatus placed on a relatively flat surface, in all three planes of human motion simultaneously; i.e. saggital, frontal and transverse planes. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 11/777,845, filed Jul. 13, 2007, now U.S. Pat. No. 8,085,382, which claims priority under 35 U.S.C. §119(e)(1) to U.S. provisional patent application Ser. No. 60/807,367, filed Jul. 14, 2006, and U.S. Provisional patent application Ser. No. 60/888,647, filed Feb. 7, 2007. U.S. application Ser. No. 11/777,845 also claims priority under 35 U.S.C. §119 to German patent application serial No. 10 2006 032 810.8, filed Jul. 14, 2006. The contents of these applications are hereby incorporated by reference in their entirety.
FIELD
The disclosure relates to optics, such as, for example, microlithographic projection exposure apparatus illumination optics, as well as related systems, methods, components and devices.
BACKGROUND
Typically, a microlithographic projection exposure apparatus includes an illumination system and a projection objective.
SUMMARY
The disclosure relates to optics, such as, for example, microlithographic projection exposure apparatus illumination optics, as well as related systems, methods, components and devices.
In one aspect, the disclosure features a microlithographic projection exposure apparatus illumination optical system. The illumination optical system has an optical path, an object plane and a pupil plane. The illumination optical system is configured so that, during use when light passes through the illumination optical system along the optical path, the illumination optical system illuminates a field of the object plane with the light. The illumination optical system includes an optical module that is configured so that during use the first optical module sets a first illumination setting in the pupil plane of the illumination optical system. The illumination optical system also includes an additional optical module that is configured so that during use the second optical module sets a second illumination setting in the pupil plane of the illumination optical system. In addition, the illumination optical system includes at least one decoupling element in the optical path upstream of the two optical modules. The decoupling element is configured so that during use the decoupling element provides light to at least one of the two optical modules. The illumination optical system further includes at least one coupling element in the optical path downstream from the two optical modules. The at least one coupling element is configured so that during use the at least one coupling element provides the light which has passed through at least one of the two optical modules to the illumination field.
In another aspect, the disclosure features a microlithographic projection exposure apparatus that includes a projection objective and the illumination optical system described in the preceding paragraph.
In a further aspect, the disclosure features a method that includes using the illumination system described in the preceding two paragraphs to make a microstructured component.
In an additional aspect, the disclosure features a system that includes a first optical module configured to be used in addition to a second optical module of illumination optics in a microlithographic projection exposure apparatus so that during use, when incorporated into the microlithographic projection exposure apparatus, the first and second optical module provide first and second illumination settings, respectively, in a pupil plane of the illumination optics. The system also includes at least one decoupling element configured to be incorporated into the illumination optics so that during use the at least one decoupling element is located in the optical path upstream from the first and second optical modules so that the at least one decoupling element provides light to at least one of the first and second optical modules. The system further includes at least one coupling element configured to be incorporated into the illumination optics so that during use the coupling element is located in the optical path downstream from the first and second optical modules so that it provides light from at least one of the first and second optical modules to the illumination field.
In one aspect, the disclosure features a microlithographic projection exposure apparatus that has a pupil plane. The microlithographic projection exposure apparatus includes a device configured so that, during use when light passes through the microlithographic projection exposure apparatus, the device alters an illumination setting in the pupil plane within a time period of 10 milliseconds or less.
In another aspect, the disclosure features a microlithographic projection exposure apparatus that has a pupil plane and that is configured to image an object into an image plane using multiple, nearly periodic pulses of light. The microlithographic projection exposure apparatus includes a device configured so that during use the device changes an illumination setting in the pupil plane from a first illumination setting to a second illumination setting.
In a further aspect, the disclosure features a system that includes a microlithographic projection exposure apparatus configured to image an object into an image plane using multiple, nearly periodic pulses of light. The microlithographic projection exposure apparatus includes a first optical element and a second optical element. The microlithographic projection exposure apparatus also includes a device configured so that during use the device alters the number of pulses between the first and second optical elements.
In an additional aspect, the disclosure features a microlithographic projection exposure apparatus configured to image an object into an image plane using multiple, nearly periodic pulses of light having an average pulse duration. The microlithographic projection exposure apparatus includes a first optical element and a second optical element. The microlithographic projection exposure apparatus also includes a device configured so that during use the device alters the average pulse duration between the first and second optical elements.
Embodiments can optionally provide one or more of the following advantages.
In some embodiments, the systems can allow for relatively fast changes in optical settings (e.g., illumination settings) during use. In some instances, fast changes of illumination settings can be desirable for multiple exposure in order to illuminate the mask briefly at two different illumination settings.
In certain embodiments, the systems can allow for relatively fast changes in optical settings (e.g., illumination settings) during use with relatively little or no movement of optical components and/or with relatively little or no light loss.
In some embodiments, such advantages can be provided, for example, by including in the system at least two optical modules that are adjusted (e.g., preadjusted) to produce specific illumination settings (e.g., polarization settings) such that it is possible to switch between the optical modules as appropriate. Optionally, switching between optical modules can be accomplished mechanically, such as, for example, by temporarily introducing a mirror into the illumination light path. Alternatively or additionally, switching between optical modules can be accomplished by modifying a characteristic of the illumination light. Under some circumstances, this can allow relatively substantially different illumination settings to be accessible with relatively little switching effort. Optionally, switching can be performed between more than two optical modules (e.g., by cascaded decoupling elements and coupling elements), which can, for example, allow for switching between more than two different illumination settings (e.g., more than two different polarization states).
In some embodiments, the change in light characteristic (e.g., polarization state) can take place in one second or less (e.g., one microsecond or less, 100 ns or less, 10 ns or less).
In some embodiments, use of polarization-selective beam splitter can result in an illumination light beam with a relatively large cross-section which can advantageously result in a relatively low-energy and/or relatively low-intensity load on the beam splitter. In certain embodiments, depending on the illumination light wavelength used, a polarization cube or a beam splitter cube used in a variation can be made of CaF 2 or of quartz. Optionally, use can also be made of a, for example, optically coated beam splitter plate which lets through light having a first polarization direction and reflects light having a second polarization direction.
Use of a Pockels cell can provide good switching between polarization states. Optionally, a Kerr cell which is suitable for changing the beam geometry can also be used. Also optionally, an acousto-optic modulator can be used as the light-characteristic changer in order to change the beam direction (the beam direction being modified by Bragg reflection).
In some embodiments, a light-characteristic changer can be particularly well suited for obtaining a light load which is distributed over the optical components and well adapted to the time characteristic of light emission of commonly used light sources.
In certain embodiments, a polarization changer can be an example of a light-characteristic changer where the light characteristic is changed by mechanically switching an optical component. The optical component can be switched so that, before and after switchover, the illumination light passes through the same optically active surface of the optical component. This is the case, for example, when a single λ/2 plate is used as a polarization changer. With other embodiments of the light-characteristic changer, various optically active regions of the optical component are used by this mechanical switching. The control expense for such a light-characteristic changer can be relatively low.
In some embodiments, use of a second polarization optical component can create the possibility of using a polarization optical beam splitter to extract the illumination light. The first polarization optical component of the polarization changer can be a λ/2 plate having, in its operating position, an optical axis which is oriented differently compared to the second polarization optical component. The first polarization optical component can be a free passage through the polarization changer.
In certain embodiments, changeover between the two optical modules can be obtained by temporarily inserting a mirror into the ray path of the illumination light. This variation requires relatively inexpensive control.
Examples of decoupling elements are known, for example, from metrology and optical scanner technology.
In some embodiments, a decoupling element can be relatively light weight.
In certain embodiments, the first illumination setting and the second illumination setting generally differ. However, in some embodiments, the second illumination setting may also be exactly the same as, or similar within predetermined tolerance limits to, the first illumination setting, so the first illumination setting does not significantly differ from the second illumination setting in any light characteristic. In such cases, the change between the illumination settings can still lead to a reduction in the optical load on the components of the first and the second optical module, as merely a respective portion of the overall illumination light acts on these optical modules. Illumination settings are also different if they differ exclusively in the polarization of the illumination light fed to the object or illumination field. Such a difference in polarization may be a difference in the type of polarization of the light passing through a local point in a pupil of the illumination optics. The pupil is in this case the region through which illumination light passes of a pupil plane which is, in turn, optically conjugate with a pupil plane of an objective, in particular a projection objective, downstream from the illumination optics. Alternatively or additionally, a difference in polarization may also be a difference in the spatial distribution of the orientation of the type of polarization relative to the pupil coordinate system beyond the various local points of the pupil. The term “type of polarization” or “polarization state” refers in the present document to linearly and/or circularly polarized light and to any form of combinations thereof such as, for example, elliptically, tangentially and/or radially polarized light. It is, for example, possible in a first illumination setting to irradiate the entire object field with a first illumination light linear polarization state which is constant over the pupil. A second illumination setting can use light having polarization rotated for this purpose through a constant angle, for example through 90°, with respect to an axis of rotation. The polarization distribution does not in this case vary on rotation about the axis of rotation through the aforementioned constant angle. Alternatively, it is possible in a first illumination setting to illuminate the pupil with a first spatial polarization distribution, for example with the same polarization over the entire pupil and in a second illumination setting to illuminate portions of the pupil with a first polarization direction of the illumination light and other portions of the pupil with a further polarization direction of the illumination light. In this case, not only the polarization direction but also the polarization distribution in the pupil is varied. Under the terms of the present application, illumination settings are different if their intensity distribution as a scalar variable and/or their polarization distribution as a vectorial variable differs over the pupil. The differing polarization states may be described as vectorial variables in the pupil based on vectorial E-field vectors of the illumination light. The pupil may in this case also have a non-planar (a curved surface). The intensity distribution is then described as a scalar variable and the polarization distribution is then described as a vectorial variable over this curved surface.
In some embodiments, the illumination settings may differ merely in terms of the polarization state, i.e. for example in the type of polarization (linear, circular) and/or in the polarization direction and/or in the spatial polarization distribution. This can allow the polarization state to be adapted to changing imaging features, especially features resulting from the geometry of the structures to be imaged.
In certain embodiments, an optical delay can allow defined time synchronization of the illumination light guided through the first optical module relative to the illumination light guided through the second optical module in the light path after the coupling element. This can be used to homogenize in time a dose of light onto the optical components from the coupling element in order thus to reduce, especially in the case of pulsed light sources, the deposition of energy per pulse in the optical components. This can apply especially to the optical components of the projection exposure apparatus arranged after the coupling element in the direction of the illumination or projection beam such as, for example, a condenser, a REMA (reticle/masking) objective, a reticle or a mask, optical components of a projection objective, immersion layers, the photoresist, the wafer and the wafer stage. The optical delay component may be an optical delay line arranged in the light path of the first optical module or in the light path of the second optical module. The optical delay can be adjustable via the optical delay component, and this can be achieved, for example, via a linear sliding table movable along a path over which the illumination light can be guided several times and a mirror, in particular a retroreflecting mirror, rigidly connected to the linear sliding table. Alternatively, and especially for setting relatively short delay paths, the optical delay component may be configured as an optically transparent and optically denser medium having a predetermined optical path. Use may also be made of a combination of an optical delay component wherein the optical delay is based on enlargement of the pure path and an optical delay component wherein the optical delay is based on a light path in an optically denser medium.
In some embodiments, the illumination optics can have a relatively small peak load on the reticle and/or on optical components downstream from the decoupling beam splitter.
In some embodiments, by changing the light characteristic during the illumination light pulse, this pulse can be split into two light pulse parts which are then shaped into different illumination settings. This can advantageously reduce the illumination light load on the components, in particular the local load on the components. By changing the light characteristic during the illumination light pulse, if a laser is chosen as the light pulse source, it is possible to work with half the laser repetition rate, twice the pulse energy and double the pulse duration. The single pulse energy is in this case the integral of the power of the individual pulse over the pulse duration thereof. In some instances, such lasers can be relatively easily integrated in a microlithographic projection exposure apparatus.
In certain embodiments, the optical modules can be subjected to a relatively low mean light output to which the optical modules are subjected because not all light pulses from the light source are conducted through the same optical module. Assuming appropriate synchronization, a decoupling element can be used instead of the light-characteristic changer. In such instances, the decoupling element can let through every second light pulse, for example, and the light pulses in between are reflected by the mirror elements of the decoupling element to the other optical module. The light-characteristic changer may, for example, be configured in such a way that the light characteristic changes between two successive light pulses.
In some embodiments, illumination light which is generated by the at least two light sources can be coupled into an illumination light beam by a coupling optical device and this light beam illuminates the illumination field. A beam splitter of the same type as the coupling or decoupling beam splitter can be used to obtain coupling; this is, however, not compulsory. Alternatively, it is possible, for example, to merge at least two illumination light beams from the light sources via coupling mirrors or coupling lenses.
In certain embodiments, the illumination system can be relatively compact.
In certain embodiments, a control system can allow proportional adjustment of illumination of the illumination field with various preset illumination settings. These components can be produced by time-proportional illumination, i.e. by sequential illumination initially with a first and then with at least one other illumination setting or by intensity-proportional illumination, i.e. parallel illumination of the illumination field with a plurality of illumination settings with a preset intensity distribution. The main control system can also be connected to the coupling element by signals for control purposes if this is necessary in order to obtain changeover between optical modules.
In some embodiments, the control system can acquire information concerning the relevant illumination setting via its signal links to the components of the illumination system, can specify specific preset lighting settings by acting on the adjustment of the optical modules and make additional adaptations, for example via the reticle masking system or scan speeds.
The systems can be used, for example, in methods to manufacture components.
In some embodiments, the optics can be in the form of a supplementary module for a microlithographic projection exposure apparatus. The supplementary module can, for example, be retrofitted to an existing illumination optics and an existing illumination system. This can, for example, allow the optics described herein to be used in pre-existing systems. This can, for example, reduce the cost and/or complexity associated with using the optics described herein.
In certain embodiments, the individual components of the supplementary module, can be designed and developed as already described above in relation to the illumination optics according to the disclosure and the illumination system according to the disclosure. The further illumination setting provided by the supplementary module may differ from the illumination setting of the first optical module. In some applications, the further illumination setting can, in this case too, correspond within predetermined tolerance limits in all light characteristics to the illumination setting of the first optical module.
A number of references are incorporated herein by reference. In the event of an inconsistency between the explicit disclosure of the present application and the disclosure in the references, the present application will control.
Embodiments of the disclosure are described below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an embodiment of a microlithographic projection exposure apparatus.
FIGS. 2 to 4 are schematic representations of two successive light pulses from a light source of a projection exposure apparatus.
FIG. 5 is a schematic representation of an embodiment of a microlithographic projection exposure apparatus.
FIGS. 6 to 9 are schematic representations of two successive light pulses from a light source of a projection exposure apparatus.
FIGS. 10 and 11 are schematic representations of embodiments of a microlithographic projection exposure apparatus
FIGS. 12 and 13 are schematic representations of embodiments of microlithographic projection exposure apparatuses.
FIG. 14 is a schematic representation of an embodiment of a decoupling element and an embodiment of a coupling element.
FIG. 15 is a schematic representation of an embodiment of a decoupling element and an embodiment of a coupling element.
FIG. 16 is a schematic representation of an embodiment of a polarization changer.
FIG. 17 is a schematic representation of an embodiment of a microlithographic projection exposure apparatus.
FIGS. 18 and 19 are schematic representations of embodiments of illumination settings.
FIGS. 20 and 21 are schematic representations of embodiments of mask structures.
FIGS. 22 and 23 are schematic representations of embodiments of illumination settings.
FIGS. 24 and 25 are schematic representations of embodiments of mask structures.
FIGS. 26 and 27 are schematic representations of embodiments of illumination settings.
FIGS. 28 and 29 show the two masks which are successively to be imaged onto the same wafer to be illuminated by double exposure with the illumination settings in FIGS. 26 and 27 , respectively.
DETAILED DESCRIPTION
FIG. 1 shows a microlithographic projection exposure apparatus 1 which can be used, for example, in the fabrication of semiconductor components and other finely structured components and which uses light in the vacuum ultraviolet range (VUV) to achieve resolutions of fractions of a micrometer. A light source 2 is (e.g., an ArF excimer laser with a working wavelength of 193 nm) produces a linearly polarized light beam 3 which is coaxially aligned with an optical axis 4 of an illumination system 5 of the projection exposure apparatus 1 . Other UV light sources (e.g., a F 2 laser with a working wavelength of 157 nm, an ArF laser with a working wavelength of 248 nm, a mercury vapour lamp with a working wavelength of 368 nm or 436 nm, light sources with wavelengths below 157 nm) can optionally be used as the light source 2 .
Light exiting from the light source 2 is initially polarized perpendicularly to the plane of projection in FIG. 1 (s-polarization). This is indicated in FIG. 1 by the individual dots 6 on the light beam 3 . This linearly polarized light from the light source 1 first enters a beam expander 7 which can be formed, for example, as a mirror arrangement (such as described, for example, in DE 41 24 311, which is hereby incorporated by reference) and is used to reduce the coherence and increase the cross-section of the beam. After the beam expander 7 , the light beam 3 passes through a Pockels cell 8 which is an example of a light-characteristic changer. In general, as long as no voltage is applied to the Pockels cell 8 , the light beam 3 is still s-polarized as it leaves the Pockels cell 8 . The light beam 3 then passes through a decoupling beam splitter 9 which is an example of a decoupling element and is formed as a polarization cube made of CaF 2 or quartz. The decoupling beam splitter 9 lets the s-polarized light beam 3 through in the direction of the optical axis 4 and the beam passes through a first diffractive optical element (DOE) 10 . The first DOE 10 is used as a beam-shaping element and is located in an entry plane of a first lens group 11 positioned in the ray path downstream therefrom.
The first lens group 11 includes a zoom system 11 a and a subsequent axicon setup 11 b . The zoom system 11 a is doubly telecentric and designed as a scalar zoom so that optical imaging with preset magnification is achieved between one entry plane and one exit plane of the zoom system 11 a . The zoom system 11 a can also have a focal-length zoom function so that triple Fourier transformation, for example, is performed between the entry plane and the exit plane of the zoom system 11 a . The illumination light distribution set after the zoom system 11 a is subjected to radial redistribution by the axicon elements of the axicon setup which can be displaced axially towards each other provided that a finite distance is set between the opposite-facing conical axicon surfaces of the axicon elements. If this gap is reduced to zero, the axicon setup 11 b basically acts as a plane-parallel plate and has practically no influence on the local distribution of illumination created by the zoom system 11 a . The axial clearance between the optical components of the zoom system 11 a and the axicon setup 11 b can be adjusted by actuators.
The first lens group 11 is part of a pupil forming element which is used to set a defined local two-dimensional illumination intensity distribution for illumination light from the light source 2 in a pupil forming plane 12 of the illumination system 5 located downstream of lens group 11 (the illumination pupil or illumination setting).
The pupil forming plane 12 which is a pupil plane of the illumination system 5 coincides with the exit plane of the first lens group 11 . A further optical raster element 13 is located in the immediate vicinity of the exit plane 12 . A coupling optic 14 located downstream therefrom transfers the illumination light to an intermediate field plane 15 in which a reticle masking system (REMA) 16 , which is used as an adjustable field stop, is located. The optical raster element 13 has a two-dimensional arrangement of diffractive or refractive optical elements and has several functions. On the one hand, incoming illumination light is shaped by the optical raster element 13 so that, after passing through subsequent coupling optic 14 in the region of the field plane 15 , it illuminates a rectangular shaped illumination field. The optical raster element 13 with a rectangular radiation pattern is also referred to as a field defining element (FDE) and generates the main component of the etendue and adapts it to the desired field size and field shape in the field plane 15 which is conjugate with a mask plane 17 . The optical raster element 13 can be designed as a prism array in which individual prisms arranged in a two-dimensional field introduce locally determined specific angles in order to illuminate the field plane 15 as required. The Fourier transformation performed by coupling optic 14 that each specific angle at the exit of the optical raster element 13 corresponds to a location in the field plane 15 whereas the location of the optical raster element 13 (its position in relation to the optical axis 4 , determines the illumination angle in the field plane 15 ). The beams emerging from the individual optical elements of the optical raster element 13 are superimposed in the field plane 15 . It is also possible to construct FDE 13 as a multistage honeycomb condenser with microcylinder lenses and diffusing screens. By constructing FDE 13 and its individual optical elements appropriately, it is possible to ensure that the rectangular field in the field plane 15 is substantially homogeneously illuminated. FDE 13 is thus also used as a field shaping and homogenising element for homogenising the field illumination so that a separate light-mixing element, for instance an integrator rod acting through multiple internal reflection or a honeycomb condenser, can be dispensed with. This can make the optical setup in this region especially axially compact.
A downstream imaging objective 18 , which is also referred to as a REMA objective, images the intermediate field plane 15 with the REMA 16 onto a reticle or its surface 19 in the mask plane 17 on a scale which can be, for example, from 2:1 to 1:5 and, in the embodiment shown in FIG. 1 , is approximately 1:1. Imaging takes place without an intermediate image so that there is precisely one pupil plane 21 between the intermediate field plane 15 , which corresponds to an object plane of imaging objective 18 and an image plane of imaging objective 18 which coincides with the mask plane 17 and corresponds to the exit plane of the illumination system and, at the same time, an object plane of downstream projection objective 20 . The latter is a Fourier transformed plane relative to the exit plane 17 of the illumination system 5 . A deflection mirror 22 , tilted at 45° with respect to the optical axis 4 and positioned between the pupil plane 21 and the mask plane 17 , makes it possible to install a relatively large illumination system 5 , which is several meters long, horizontally and, at the same time, keep the reticle 19 horizontal.
Those optical components which guide illumination light from the light source 2 and, from it, form the illumination light which is directed at the reticle 19 are part of the illumination system 5 of the projection exposure apparatus. Downstream from the illumination system 5 there is a device 23 for holding and manipulating the reticle 19 arranged so that a pattern on the reticle falls in object plane 17 of the projection objective 20 and, in this plane, can be moved with the aid of a scan drive for scan operation in a scan direction which is perpendicular to the optical axis 4 .
The projection objective 20 is used as a reduction objective and forms an image of the reticle 19 on a reduced scale, for example on a 1:4 or 1:5 scale, on the wafer 24 which is coated with a photoresistive layer or photoresist layer, the light-sensitive surface of which lies in image plane 25 of the projection objective 20 . Refractive, catadioptric or catoptric projection objectives are possible. Other reduction scales, for instance greater minification, up to 1:20 or 1:200 are possible.
The semiconductor wafer 24 which is to be exposed is secured by the device 26 configured to hold and/or manipulate it which includes a scanner drive in order to move the wafer 24 , in synchronism with the reticle 19 , perpendicularly to the optical axis 4 . These movements can be parallel to each other or anti-parallel, depending on the design of the projection objective 20 . The device 26 , which is also referred to as a wafer stage, and the device 23 , which is also referred to as a reticle stage, are component parts of a scanner which is controlled via a scan controller.
The pupil forming plane 12 is located on or close to a position which is optically conjugate with next downstream pupil plane 21 and with image-side pupil plane of the projection objective 20 . This way, the spatial and local light distribution in the pupil plane 27 of the projection objective 20 can be determined by the spatial light distribution and local distribution in the pupil forming plane 12 of the illumination system 5 . Between each of the pupil surfaces 12 , 21 and 27 , there are field surfaces in the optical ray path which are Fourier-transformed surfaces relative to the relevant pupil surfaces. This can allow for a defined local distribution of illumination intensity in the pupil forming plane 12 can result in a specific angular distribution of the illumination light in the region of the downstream field plane 15 which, in turn, can correspond to specific angular distribution of the illumination light which falls onto the reticle 19 . Together with the first DOE 10 , the first lens group 11 forms a first optical component 28 configured to set a first illumination setting in the illumination pupil 12 .
In some embodiments, the illumination system 5 can allow for relatively fast modification of the illumination pupil 12 during an illumination process (e.g., for an individual reticle 19 ). This can make double exposure or other multiple exposure possible at short time intervals.
A second optical module 29 , which is located in the decoupling path 29 a of the decoupling beam splitter 9 , can be used for fast modification of the illumination setting in the pupil forming plane 12 . The second optical module 29 includes the second DOE 30 and a second lens group 31 which is, in turn, divided up into a zoom system 31 a and the axicon setup 31 b . The two optical modules 28 , 29 are of similar construction. The optical effect and the layout of the individual optical components of the zoom system 31 a , the axicon setup 31 b and of second DOE 30 are, however, different from the first optical module 28 so that illumination light from the light source 2 which passes through the second optical module 29 is influenced so that a second illumination setting which differs from the first illumination setting created by the first optical module 28 is produced in the pupil forming plane 12 .
Decoupling path 29 a is indicated in FIG. 1 by the dashed line. In the decoupling path 29 a , the illumination light is guided in the parallel polarization direction (p-polarization) relative to the plane of projection in FIG. 1 which is indicated in FIG. 1 by double arrows 32 which are perpendicular to the optical axis in the decoupling path 29 a.
A deflection mirror 33 is positioned, in the same way as the deflection mirror 22 , between the decoupling beam splitter 9 and the second DOE 30 . Another deflection mirror 34 is positioned between the axicon setup 31 b of the second lens group 31 and a coupling beam splitter 35 which is constructed as a polarization cube like the decoupling beam splitter 9 . The coupling beam splitter 35 is an example of a coupling element. The coupling beam splitter 35 is located in the optical path between the axicon setup 11 b of the first lens plane 11 and the optical raster element 13 . The illumination light guided onto the decoupling path 29 a is deflected by the coupling beam splitter 35 so that, downstream from the coupling beam splitter, it travels precisely along the optical axis 4 .
High voltage, typically 5 to 10 kV, can be applied to the Pockels cell 8 in order to obtain a rapid change of illumination setting. When high voltage is applied to the Pockels cell 8 , the polarization of the illumination light can be rotated (e.g., from s to p) within a few nanoseconds. The p-polarized illumination light is extracted in the decoupling path 29 a because a polarizer in the decoupling beam splitter 9 acts as a reflector for p-polarization. In the decoupling path 29 a , the illumination light is subjected to different setting adjustment to the s-polarized illumination light which is not extracted. After deflection by the deflection mirror 34 via the coupling beam splitter 35 , the polarizer of which acts as a reflector for p-polarized light, p-polarized illumination light which has passed through the second optical module 29 is coupled again in the direction of the optical axis 4 .
The light source 2 can generate, for example, laser pulses having a duration of 150 ns or 100 ns and a single pulse energy of, for example, 30 mJ or 15 mJ at a repetition rate of, for example, 6 kHz.
FIGS. 2 to 4 show various examples of switching times for high-voltage switching instants t s of the Pockels cell 8 . FIGS. 2 to 4 all schematically show consecutive individual rectangular pulses L from the light source 2 at interval t z =t 2 -t 1 which corresponds to the reciprocal of the 6 kHz repetition rate. In the switching-time example in FIG. 2 , the Pockels cell 8 switches between every two laser pulses L. Laser pulse L 1 shown on the left in FIG. 2 passes through the Pockels cell without voltage being applied and therefore remains p-polarized. The polarization of subsequent laser pulse L 2 is rotated through 90° because switching instant t s has occurred and it therefore passes through the decoupling path 29 a . The next laser pulse (not shown) passes through the Pockels cell 8 without its polarization being altered. In the case of the switching-time example in FIG. 2 , every second laser pulse is therefore fed through the decoupling path 29 a whereas the other laser pulses are not decoupled. The reticle 19 is therefore subjected to alternate illumination with two different illumination settings which correspond to the setting of the optical modules 28 , 29 respectively and the laser pulses for each illumination setting have a repetition rate of 3 kHz. The radiation load incident on the reticle and the optical components of the illumination system downstream from the decoupling beam splitter 9 is determined by the energy and peak intensity of each individual laser pulse L.
In the switching-time example in FIG. 3 , the Pockels cell 8 switches while a single laser pulse L is passing through it. Individual laser pulse L is therefore split into pulse parts L 1 , L 2 . In the example in FIG. 3 , polarization of the leading laser pulse part L 1 is unaffected and it therefore remains s-polarized. In contrast, the polarization of the subsequent laser pulse part L 2 is subjected to rotation because it passes through the Pockels cell 8 after switching instant t s , and is extracted and creates a different illumination setting to laser pulse part L 1 . The two laser pulse parts L 1 and L 2 have a pulse duration equivalent to roughly half the pulse duration of the non-divided laser pulse which, in this embodiment, is therefore around 50 or 75 ns. The energy of the laser pulse parts is roughly half the energy of individual laser pulses (7.5 mJ or 15 mJ). The polarization of leading laser pulse part L 2 of the subsequent laser pulse in FIG. 3 is rotated and is therefore p-polarized. Voltage is removed from the Pockels cell 8 at switching instant t s , so that the polarization of next laser pulse part L 1 is no longer affected and therefore remains s-polarized. This second laser pulse is therefore split. Switching repeats accordingly during laser pulses for subsequent laser pulses from the light source 2 which are not shown. In the switching-time example in FIG. 3 , one laser pulse part is therefore fed through the decoupling path 29 a , i.e. through the optical module 29 , and the other laser pulse part is fed through the other optical module 28 . In this switching-time example, the reticle 19 is illuminated at an effective repetition rate of 6 kHz with the first illumination setting and illuminated at the same effective repetition rate of 6 kHz with the second illumination setting. Because of the halving of the pulse energy in the laser pulse parts, the peak load on the reticle and the optical components downstream from the decoupling beam splitter 9 is reduced by a factor of roughly 2 . In practice, this reduction factor can be even higher because the two different illumination settings generated by the optical modules 28 , 29 , in general, impinge on different regions of the pupil with different polarization characteristics.
In the switching-time example in FIG. 4 , the Pockels cell 8 switches three times for each laser pulse L. In the case of leading laser pulse L shown on the left in FIG. 4 , high voltage is initially applied to the Pockels cell but this voltage is then switched off and applied again. The left-hand laser pulse shown in FIG. 4 is therefore split into leading laser pulse part L 1 with s-polarization, subsequent laser pulse part L 2 with p-polarization, yet another subsequent laser pulse part L 1 with s-polarization and final laser pulse part L 2 with p-polarization. In the case of laser pulse L shown on the right in FIG. 4 , these conditions are precisely reversed because when the Pockels cell 8 first switches during laser pulse L shown on the right in FIG. 4 , the high voltage is initially switched off. The right-hand laser pulse L shown in FIG. 4 therefore has a leading p-polarized laser pulse part L 2 , a subsequent s-polarized laser pulse part L 1 , a subsequent p-polarized laser pulse part L 2 and a final s-polarized laser pulse part L 1 . In the case of the switching-time example in FIG. 4 , the illumination light impinges on the reticle 19 with an effective repetition rate of 12 kHz for both illumination settings. In the case of the switching-time example in FIG. 4 , the light pulse parts L 1 and L 2 have a pulse duration of approximately 25 or 37.5 ns and a pulse energy of approximately 3.75 or 7.5 mJ. Because the individual light pulses are quartered by the triple switching of the Pockels cell 8 during one light pulse L, the peak load on the reticle 19 and on the optical components downstream from the decoupling beam splitter 9 drops by a factor of 4.
Depending on polarization state, the service life of optical materials depends not only on peak illumination power H, but also on the number of pulses N and the pulse duration T of the laser pulses. Various theoretical models in relation to this, which are familiar to persons skilled in the art, have been developed. One of these models is the polarization double refraction model according to which the load limit of optical materials depends on the product H×N. With the so-called compaction model or the microchannel model, the load limit depends on the product H 2 ×N/T.
Comparative analysis shows that it is possible to use a laser 2 with a halved repetition rate (number of pulses N/2), doubled pulse laser power (2H) and doubled pulse duration (2T) for double exposure by once-only changeover by the Pockels cell 8 during one laser pulse. Such lasers with a half repetition rate and doubled power are one possible way of increasing the performance of current lithographic lasers and can be implemented simply. Using the light-characteristic changer 8 makes it possible to use a 6 kHz laser in microlithographic applications which were previously only possible using a 12 kHz laser. The constructional requirements placed on the laser light source become commensurately less demanding.
A polarization-changing light-characteristic changer other than the Pockels cell 8 can be used to influence the polarization of the illumination light, for example a Kerr cell.
Instead of polarization, a different characteristic of the illumination light can be influenced by the light-characteristic changer, for example the light wavelength. In this case, dichroitic beam splitters can be used as the decoupling beam splitter 9 and as the coupling beam splitter 35 .
The beam geometry of the light beam 3 or its direction can be the light characteristics that are modified by an appropriate light-characteristic changer in order to switch between the two optical modules 28 , 29 . A Kerr cell or an acousto-optic modulator can be used as an appropriate light-characteristic changer.
An embodiment with two optical modules 28 , 29 is described above. It is equally possible to provide more than two optical modules and switch between them. For example, another Pockels cell which rotates the polarization of the illumination light at preset switching times, thereby causing extraction into another decoupling load which is not shown in FIG. 1 , can be provided between the decoupling beam splitter 9 and DOE 10 or in the decoupling path 29 a . This way, it is possible to obtain fast changeover between more than two illumination settings.
The Pockels cell 8 can also be located inside the light source 2 and chop the laser pulses generated in the light source 2 into several light pulse parts of the same kind as parts L 1 and L 2 . This can result in little or no laser coherence and can, for example, reduce the possibility of undesirable interference in the mask plane 17 .
FIG. 5 shows an embodiment of an illumination system. Components that are identical to those already described above with reference to FIGS. 1 to 4 have the same reference numerals and are not individually described again. The illumination system in FIG. 5 can be implemented in combination with all the design variations that are described above with reference to the embodiment in FIGS. 1 to 4 .
In addition to the light source 2 , the illumination system 5 in FIG. 5 has another light source 36 , the internal construction of which can be identical to that of the light source 2 . Downstream from the light source 36 , there is a beam expander 37 , the construction of which can be identical to that of the beam expander 7 . A light beam 38 from the light source 36 is expanded by the beam expander 37 (e.g., as already described in connection with the light beam 3 from the light source 2 ). Downstream from beam expander 37 , there is a Pockels cell 39 . After exiting the other light source 36 , the light beam 38 is also initially s-polarized as indicated by dots 6 on the light beam 38 . As long as no voltage is applied to the Pockels cell 39 , the light beam 38 remains s-polarized after passing through the Pockels cell 39 . After the Pockels cell 39 , the light beam 38 impinges on a second decoupling beam splitter 40 . The light beam splitter 40 lets s-polarized light through and reflects p-polarized light to the right by 90° in FIG. 5 . A polarization-selective deflection element 41 is located downstream from the second decoupling beam splitter 40 in the beam splitter's forward direction. The deflection element is for s-polarized light which is incident from the direction of the second decoupling beam splitter 40 , reflecting to the right by 90° in FIG. 5 , and it lets p-polarized light through unimpeded.
Using the illumination system 5 in FIG. 5 , light from the two light sources 2 and 36 can be injected optionally into the two optical modules 28 , 29 .
When no voltage is applied to the two Pockels cells 8 and 39 , the light source 2 illuminates the first optical module 28 because s-polarized light beam 3 from the two decoupling beam splitters 9 and 40 is allowed through unimpeded. As long as no voltage is applied to the two Pockels cells 8 and 39 , the second light source 36 illuminates the second optical module 29 because the second decoupling beam splitter 40 lets the s-polarized light of the light beam 38 through unimpeded and this s-polarized light is deflected into the second optical module 29 by the deflection element 41 .
When voltage is applied to the first Pockels cell 8 but not to the second Pockels cell 39 , the two light sources 2 and 36 illuminate the second optical module 29 . The now p-polarized light from the first light source 2 is extracted from the decoupling beam splitter 9 , as described above, into the decoupling path 29 a and, after deflection by the deflection mirror 33 , passes through the deflection element 41 unimpeded so that it can enter the second optical module 29 . The optical path of the light beam 38 from the second light source 36 remains unchanged.
When voltage is not applied to the first Pockels cell 8 , but is applied to the second Pockels cell 39 , the two light sources 2 and 36 illuminate the first optical module 28 . The s-polarized light from the first light source 2 can pass through the two decoupling beam splitters 9 and 40 unimpeded and enters the first optical module 28 . The light of the light beam 38 from the second light source 36 rotated into p-polarization by the second Pockels cell is reflected through 90° by the second decoupling beam splitter 40 and enters the first optical module 28 .
When light from the two light sources 2 and 36 collectively impinges on one of the optical modules 28 , 29 , the light from the two light sources 2 and 36 which collectively passes through the optical module 28 or 29 can have two different polarization states.
P-polarized light which has passed through the first optical module 28 is reflected by the coupling beam splitter 35 in FIG. 5 upwards along the optical path 42 , from where it has to be brought back in the direction of the optical axis 4 by another appropriate coupling device. The same applies to s-polarized light which is fed through the second optical module 29 and which passes through the coupling beam splitter 35 , without being deflected thereby, in the direction of the optical path 42 .
When voltage is applied to the two Pockels cells 8 and 39 , light from the light source 2 is conducted through the second optical module 29 and light from the light source 36 is conducted through the first optical module 28 . FIGS. 6 and 7 show the possible characteristics, as a function of time, of the intensities I 1 of the light pulses L from the first light source 2 and of the intensities I 2 of the light pulses L′ from the second light source 36 . The two light sources 2 and 36 are synchronized with each other so that light pulses L′ are generated during the gaps between two light pulses L. Two light pulses L and L′ therefore do not impinge simultaneously on the second decoupling beam splitter 40 and the deflection element 41 . Also, beyond the coupling beam splitter 36 , laser pulses L and L′ do not simultaneously impinge on downstream optical components of the illumination system 5 or on the reticle 19 and the wafer 24 . As described above with reference to FIGS. 2 to 4 , laser pulses L and L′ can be split into two or more laser pulse parts L 1,2 and L′ 1,2 by one or more optical polarization components and appropriate switching times. This reduces the illumination light load on the optical components as already described above with reference to FIGS. 2 to 4 .
Two pulsed light sources with pulse waveforms according to FIGS. 6 and 7 can also be combined upstream from a single Pockels cell of the illumination system. To achieve this, light 3 , for example, from the second light source 2 upstream from beam expander 7 can be injected into the optical path of the light beam 3 with the aid of a perforated mirror 2 a which is tilted 45° relative to the optical axis 4 . The light source 2 ′, the light beam 3 ′ and the perforated mirror 2 a are shown in a dashed line in FIG. 1 . The light beam 3 ′ is also s-polarized. The light beam 3 ′ from the light source 2 ′ ideally has a mode which carries practically no energy in the region of a central hole in the perforated mirror 2 a . The light beam 3 from the light source 2 passes through the hole in the perforated mirror 2 a . The beam expander 7 is then illuminated by merged light beams 3 and 3 ′. The Pockels cell 8 is then used as a common Pockels cell in order to influence the polarization state of the light beams 3 and 3 ′.
FIGS. 8 and 9 show another way of reducing the illumination light load on individual components of the illumination system 5 in FIG. 5 in situations where the light pulses L and L′ of the two light sources 2 and 36 overlap in time. FIG. 8 shows the intensity I 1 of the light pulses L from the light source 2 . FIG. 9 shows the intensity I 2 of the light pulses L′ from the light source 36 . The Pockels cell 8 is deenergized before the arrival of the first laser pulse L at t=t s0 . Laser pulse part L 1 therefore passes through the first optical module 28 . The second Pockels cell 39 is also deenergized at t=t s0 in synchronism with the first Pockels cell 8 . Switching instant t s0 coincides with the centre of a laser pulse L′ of the second light source 36 , so that subsequent light pulse part L′ 2 is then conducted through the second optical module 29 . In period T D between the rising edge of laser pulse L and the trailing edge of laser pulse L′ following switching instant t s0 during which the two laser pulses L and L′ overlap, the two laser pulses L and L′ are therefore separately conducted through the optical modules 28 , 29 so that there is no simultaneous loading by the two laser pulses L and L′. At the next switching instant t s1 , voltage is applied to the two Pockels cells 8 and 30 in synchronism. Switching instant t s1 coincides with the centre of laser pulse L of the light source 2 . Subsequent laser pulse part L 2 therefore passes through the second optical module 29 . In contrast, laser pulse part L′ 1 of next laser pulse L′ of the second light source 36 which overlaps with this laser pulse part L 2 is conducted through the first optical module 28 .
At switching instant t s2 in the centre of next laser pulse L′, the process described with reference to switching instant t s0 repeats. The frequency of switching instants t s is twice that of the laser pulses of individual light sources 2 and 36 , with laser pulse L and L′ of one light source being halved and with switching between two laser pulses L′ and L of the other light source. This circuit ensures that light from the two light sources 2 and 36 is never conducted through a single optical module 28 or 29 and this reduces the load on the individual optical components of the optical modules 28 , 29 accordingly.
FIG. 10 shows an embodiment of the illumination system 5 . Components that are identical to those already described above with reference to FIGS. 1 to 9 have the same reference numerals and are not individually described again. The variation in FIG. 10 is equivalent to the variation in FIG. 5 , apart from the way in which the light from the second light source 36 is extracted. In FIG. 10 , the decoupling beam splitter 9 , which already extracts the light beam 3 of the light source 2 , is used to extract the light beam 38 of the second light source 36 .
The decoupling beam splitter 9 firstly lets the s-polarized light of the light source 2 and secondly lets the s-polarized light of the light source 36 through unimpeded, so that s-polarized light from the light source 2 impinges on the first optical module 28 and s-polarized light from the second light source 36 impinges on the second optical module 29 . The decoupling beam splitter 9 reflects the p-polarized light of the light sources 2 and 36 through 90° respectively, so that p-polarized light from the second light source 36 impinges on the first optical module 28 and p-polarized light from the first light source 2 impinges on the second optical module 29 .
In terms of coupling, the variation in FIG. 10 corresponds to that in FIG. 5 .
In terms of the switching times of the Pockels cells 8 and 39 , the examples of switching times described above with reference to FIGS. 6 to 9 can also be used in the system shown in FIG. 10 .
In some embodiments, the change in light characteristic in order to change the optical path between the optical modules 28 , 29 can take place in one second or less (e.g., one microsecond or less, 100 ns or less, 10 ns or less).
Switching of the Pockels cells 8 and 39 can be periodic at a fixed frequency. This frequency can be around 1 kHz, for example. Other exemplary frequencies are in the range from 1 Hz to 10 kHz.
By changing the light characteristic, it is believed that it is possible to ensure that the maximum laser power per laser pulse after creating an illumination setting in the pupil plane 12 is at least 25% lower than it would be using a conventional illumination system with the same setting measured at the same location.
The maximum intensity at a specific location in the illumination system can be, for example, up to 25% lower in the case of the designs according to the disclosure than in the case of conventional illumination systems with just one optical module.
Instead of the coupling beam splitter 35 , an optical system which integrates the two optical paths can be provided in the form of, for example, a lens, an objective or a refractive mirror or a plurality of such mirrors. One example of such an optically integrating system is described in WO 2005/027207 A1.
FIG. 11 shows an embodiment of a projection exposure apparatus 1 configured to produce proportional illumination of the illumination field via the first optical module 28 , on the one hand, and via the second optical module 29 , on the other hand, e.g. for specified double exposure of the reticle 19 using the two illumination settings that can be set via the optical modules 28 , 29 . Components of the projection exposure apparatus 1 in FIG. 11 that are identical to those already described above with reference to the projection exposure apparatus 1 in FIGS. 1 to 10 have the same reference numerals and are not individually described again.
The project exposure apparatus 1 in FIG. 11 has a main control system in the form of, for example, a computer 43 (e.g., to specify proportional illumination). The computer 43 is connected to a control module 45 by a signal cable 44 . The control module 45 is connected by signals to the light source 2 by a signal cable 46 , to a light source 2 ′ by a signal cable 47 and to the Pockels cell 8 by a signal cable 48 . The computer 43 is connected to the zoom systems 11 a and 31 a by the signal cables 49 and 50 . The computer 43 is connected to the axicon setups 11 b and 31 b by signal cables 51 and 52 . The computer 43 is connected to the REMA 16 by a signal cable 53 . The computer 43 is connected to the wafer stage 26 by a signal cable 54 and to the reticle stage 23 by a signal cable 55 . The computer 43 has a display 56 and a keyboard 57 .
The computer 43 specifies the switching instants t s for the Pockels cell 8 . By selecting the switching instants over time with the aid of the computer 43 , it is possible to specify the intensity with which reticle 19 is illuminated using either of the two illumination settings that can be produced via the two optical modules 28 , 29 . The switching instants for the Pockels cell 8 can be synchronized with trigger pulses of the light sources 2 and 2 ′ so that switching instants occur in correct phase relation during laser pulses as described above in connection with FIGS. 2 to 8 .
Switching instants t S are specified depending on the particular illumination settings previously set in the optical modules 28 , 29 . The computer 43 receives information regarding the particular previously set illumination setting over the signal cables 49 to 52 . The computer 43 can also actively set a predefined illumination setting by controlling appropriate displacement drives for the zoom systems 11 a and 31 a and for the axicon setups 11 b and 31 b over the corresponding signal cables.
Switching instants t s are also specified depending on the particular scanning process. The computer 43 receives information concerning this from the REMA 16 and stages 23 and 26 via the signal cables 53 to 55 . Depending on the specified value, the computer 43 can also actively change the operating position of the REMA 16 and stages 23 and 26 by controlling appropriate drives via the signal cables 53 to 55 . This way, the computer 43 can, depending on the particular operating situation of the projection exposure apparatus 1 , make sure that each of the two optical modules 28 , 29 contributes sufficient light to illuminate the illumination field on reticle 19 . The computer 43 determines the relevant light contribution by integrating the intensity curves (cf. FIGS. 2 to 4 and FIGS. 7 to 9 ). Any excess light which is not needed for projection exposure can be coupled out of the exposure path by using a second Pockels cell and a downstream polarizer.
The main control system 43 can also be connected by signals to the decoupling element 9 and/or coupling element 35 if this is necessary in order to specify proportional illumination of the illumination field using the illumination settings that can be achieved via the optical modules 28 , 29 .
The main control system 43 makes time-proportional illumination of the illumination field on the reticle 19 possible via the first optical module 28 and the second optical module 29 . Alternatively or additionally, the main control system 43 can also be used to obtain intensity-proportional illumination of the illumination field via the first optical module 28 and the second optical module 29 . For instance, it is possible to illuminate the illumination field at 30% of total intensity via the first optical module 28 and at 70% of total intensity via the second optical module 29 . This can be performed statically so that these percentages do not change over a predefined period. Alternatively, it is also possible to vary these proportions dynamically. To achieve this, the Pockels cell 8 can be driven, for example, by a sawtooth waveform having 1 ns timebase. To achieve this, the control circuit of the Pockels cell 8 can have a least one high-voltage generator. If fast switching between two voltages is desirable, the control circuit of the Pockels cell 8 can have two high-voltage generators. Besides high-voltage switching on a nanosecond timescale, there can also be additional high-voltage switching, for example on a millisecond timescale, so that, measured against the duration of the laser pulses, slow transitions between illumination settings that can be specified via the optical modules 28 , 29 are possible.
FIG. 12 shows an embodiment of the projection exposure apparatus 1 . Components that are identical to those already described above with reference to FIGS. 1 to 11 have the same reference numerals and are not individually described again.
In contrast to the projection exposure apparatus in FIGS. 1 , 5 , 10 and 11 , the projection exposure apparatus 1 in FIG. 12 has pupil forming planes 58 and 59 which are each located in the optical paths to the optical modules 28 , 29 and are therefore directly assigned to them. The pupil forming plane 58 is directly downstream from the axicon setup 11 b of the first optical module 28 . The pupil forming plane 59 is directly downstream from the axicon setup 31 b of the second optical module 29 (located in the decoupling path 29 a ).
In the embodiment in FIG. 12 , the pupil forming planes 58 and 59 replace the pupil forming plane 12 in FIG. 12 . Alternatively, it is possible for the pupil forming planes 58 and 59 to be optically conjugate with the pupil forming plane 12 .
Individual raster elements corresponding to raster element 13 in the projection exposure apparatus 1 in FIG. 1 can be assigned to the pupil forming planes 58 and 59 .
In the case of the embodiment of the illumination system 5 in FIG. 12 , pupil forming, i.e. setting an illumination setting, can be performed by using appropriate optical components in optical modules 28 , 29 , as is known in principle from the prior art, e.g. from WO 2005/027207 A.
Other components for influencing a pupil setting which can be used in optical modules 28 , 29 are described in WO 2005/069081 A2, EP 1 681 710 A1, WO 2005/116772 A1, EP 1 582 894 A1 and WO 2005/027207 A1, which are hereby incorporated by reference.
FIG. 13 shows an embodiment of the illumination system 5 of the projection exposure apparatus 1 . Components that are identical to those already described above with reference to FIGS. 1 to 12 have the same reference numerals and are not individually described again.
In contrast to the illumination systems 5 in FIGS. 1 to 12 , the mechanism for obtaining decoupling between optical modules 28 , 29 in the case of the illumination system 5 in FIG. 13 is not based on influencing a light characteristic which is subsequently used to alter an optical path, but on directly influencing the path of the illumination light. To achieve this, the decoupling element 60 is provided in the form of a mirror element. The decoupling element 60 is located at the position of the decoupling beam splitter 9 , e.g. in the embodiment in FIG. 1 , and can rotate around axis 61 which lies in the projection plane of FIG. 13 . This rotating movement is driven by a rotary drive 62 . The rotary drive 62 is connected to synchronization module 63 by the signal cable 64 . The decoupling element 60 has a disc-shaped mirror mount 65 , part of which is shown in FIGS. 13 and 14 . A multiplicity of individual mirrors 67 are fitted over the circumferential wall 66 of the mirror mount 65 and project beyond said wall.
The representation in FIG. 14 is not true scale. In fact, there can be a large number of individual mirrors 67 , for example several hundred such individual mirrors, on the mirror mount 65 .
In the circumferential direction, the gap between two adjacent individual mirrors 67 is equivalent to the circumferential extent of a single mirror 67 . The individual mirrors 67 all have the same circumferential extent.
When the mirror mount 65 rotates, illumination light is either reflected by one of the mirrors 67 or passes between the individual mirrors 67 and is uneffected. Reflected illumination light impinges on the decoupling path 29 a , i.e. the second optical module 29 . Illumination light which is let through impinges on the first optical module 28 .
In the case of the embodiment in FIG. 13 , a coupling element 68 is located at the position of the coupling beam splitter 35 in the embodiment in FIG. 1 and the coupling element 68 has precisely the same structure as the decoupling element 60 . The coupling element 68 is only shown schematically in FIG. 13 . The coupling element 68 , controlled by control module 63 , is driven in synchronism with the decoupling element 60 so that whenever the decoupling element 60 lets illumination light through, the coupling element 68 also lets illumination light through unaffected. In contrast, when the decoupling element 60 reflects illumination light with one of the mirrors 67 , this extracted illumination light, after passing through the decoupling path 29 a , is reflected by a corresponding individual mirror of the coupling element 68 and is thereby injected into the adjacent common illumination light ray path towards reticle 19 .
The speed of rotation of the coupling element 60 and that of the decoupling element 68 is synchronised with the pulse sequence from the light sources 2 and 2 ′.
Owing to the aspect ratio of the circumferential extent of the individual mirrors 67 relative to the circumferential extent of the gaps between adjacent the individual mirrors 67 of the decoupling element 60 and of the coupling element 68 , it is possible to specify the proportion of illumination via the first optical module 28 on the one hand and via the second optical module 29 on the other hand. Such aspect ratios can be defined by the configuration and arrangement of the individual mirrors 67 on the circumferential wall 66 of the mirror mount 65 (e.g., from 1:10 to 10:1).
FIG. 15 shows an embodiment of the decoupling element 60 which can also be used in this form as the coupling element 68 . The decoupling element 60 is in the form of strip-shaped mirror foil 69 . The mirror foil 69 is divided up into individual mirrors 70 between which there are transparent gaps 71 through which illumination light can pass. The mirror foil 69 is an endless loop which is transported over corresponding guide rollers so that, at the location of the individual mirrors 67 in the embodiment in FIG. 13 , it is transported perpendicularly to the plane of projection through the ray path of illumination light 3 . In general, as long as illumination light is reflected by one of the individual mirrors 70 , it is reflected by the decoupling element 60 into the decoupling path 29 a and injected by the coupling element 68 back into the common ray path towards reticle 19 . The illumination light is not affected by the transparent gaps 71 so that, in the case of the decoupling element 60 , it passes through to the first optical module 28 and, in the case of the coupling element 68 , it passes through to reticle 19 .
The explanations given above regarding aspect ratios in connection with coupling and decoupling elements 60 and 68 in FIG. 14 also apply to the control of the mirror foil 69 driven via control module 63 and to the aspect ratio of the lengths of the individual mirrors 70 and the lengths of the gaps 71 .
FIG. 16 shows a polarization changer 72 which can be used instead of the decoupling element 60 . The polarization changer 72 is installed in the illumination system 5 in FIG. 1 at the location of the Pockels cell 8 . The polarization changer 72 is rotatably driven around the rotation axis 76 which runs parallel to the light beam 3 between the light source 2 and the decoupling beam splitter 9 . The polarization changer 72 is rotatably driven around the rotation axis 76 by an appropriate rotary drive synchronised via control module 63 . The polarization changer 72 has a revolving support 73 with a total of eight revolving receptacles 74 . A significantly larger number of receptacles 74 is possible. A λ/2 plate 75 is fitted in every second receptacle 74 in the circumferential direction. The other four receptacles 74 are empty. The optical axes of the four λ/2 plates 75 in total are therefore arranged so that, when one of the λ/2 plates 75 is in the ray path of the illumination light, the polarization of the illumination light is rotated through 90° as it passes through the λ/2 plate. The polarization changer 72 then has the same function as the Pockels cell 8 when high voltage is applied to it.
When one of the empty receptacles 74 lets the illumination light through unaffected, the polarization changer 72 functions as a deenergized Pockels cell.
A rotatable polarization-changing plate as described, for example in WO 2005/069081 A can be used as an alternative to the polarization changer 72 .
A λ/2 plate placed in the ray path of illumination light beam 3 , for example at the location of the Pockels cell 8 in the setup in FIG. 1 and which replaces the Pockels cell 8 , can also be used as another alternative to the polarization changer 72 . By rotating the λ/2 plate around a rotation axis parallel to illumination light beam 3 which passes through it, the polarization plane of the illumination light can be rotated through 90°, for example, so that the λ/2 plate has a polarization-changing effect equivalent to that of the Pockels cell 8 in the embodiment in FIG. 1 . The optical axis of the λ/2 plate is in the plane of the plate as a rule. Other orientations of the optical axis of the λ/2 plate relative to the plane of the plate are also possible. Polarization-changing elements of the same kind as λ/2 plates are described, for example, in DE 199 21 795 A1, US 2006/0055834 A1 and WO 2006/040184 A2, which are hereby incorporated by reference.
Embodiments are described above assuming that the illumination system already includes two optical modules 28 , 29 . According to the disclosure, it is also possible to retrofit existing projection exposure apparatuses having an optical module equivalent to the first optical module 28 in the embodiments described above with a supplementary module, thereby producing one of the embodiments described above. The retrofit supplementary module includes, besides the second optical module 29 , the decoupling element 9 or 60 and the coupling element 35 or 68 . Depending on the design of the supplementary module, it also has a light-characteristic changer, for example the Pockels cell 8 or the polarization changer 72 . The main control system 43 may also be part of the supplementary module. The supplementary module may also include another light source 2 ′ or 36 with appropriate coupling and decoupling optics (e.g., as described above in connection with FIGS. 1 and 5 ).
Embodiments have been described with reference to two differing illumination settings having differing spatial intensity distributions in the pupil or pupil plane 12 . The term “illumination setting” refers not only to the spatial intensity distribution but also to the spatial polarization distribution in the pupil.
Using the at least two optical modules 28 , 29 , it is also possible to adjust a single spatial illumination setting with regard to the spatial intensity distribution in the pupil plane 12 , the illumination settings differing merely in terms of their spatial polarization distribution in the pupil plane 12 . Depending on the structures to be imaged, the second illumination setting can, for example, have a polarization distribution rotated through 90° in the pupil plane 12 relative to the polarization distribution of the first illumination setting in the pupil plane 12 . It is thus possible, by suitable activation of the two optical modules 28 , 29 , to control the proportional illumination thereof using a control unit, such as for example the computer 43 , so as to allow, for a single intensity illumination setting with which the reticle 19 is illuminated, various polarization states to be achieved during the illumination.
This can be advantageous, for example, if manufacturing processes are to be transferred from development installations in development centres to production installations in factories for manufacturing microstructured components or chip factories and these differing installations, in particular the projection objectives thereof for imaging mask structures onto the wafer, differ in terms of their polarization transfer characteristics. In such a case, it can be advantageous if, for a single intensity illumination setting, the development of which has been found to be optimal for a specific chip structure, use of the two optical modules allows the polarization characteristic to be controlled, so the production installations operated therewith also image optimum chip structures onto the wafer. Another application of the change in polarization characteristic at a single intensity illumination setting is obtained on illumination of chips in a scanning process in which, although a single intensity illumination setting was selected for illuminating the entire chip, the chip structures in differing regions of the chip can be imaged with higher contrast by differing polarization. In this case, it can be desirable to vary the polarization characteristics during the scanning process. In addition, the spatial intensity distribution of the illumination settings (e.g., intensity illumination setting), generated by the at least two optical modules, can also be altered during the scanning process.
A further aspect in the change in polarization characteristics at a single illumination setting can be obtained from what is known as polarization-induced birefringence. This is a material effect based on the fact that polarized irradiation of the material causes over time stress birefringence in the material through which the illumination light passes. Such material regions with illumination-induced stress birefringence form defect regions in the material. In order to prevent these material defects, circular or unpolarized light is, if possible, used. The present disclosure can allow the polarization characteristic to be altered at a single intensity illumination setting, thus allowing polarization-induced birefringence to be reduced, at least for the optical components following the coupling element.
Based on the foregoing embodiments, it is also possible using the at least two optical modules 28 , 29 to generate any desired illumination settings having any desired polarization distributions in the pupil plane 12 . It is in this case also possible to change rapidly between the illumination settings having the corresponding polarization states—up to a plurality of changes within a light pulse. Furthermore, it is possible to allow slow changes of the illumination settings in synchronism with the scanning process and at the same time to alter the polarization distribution within the at least two optical modules 28 , 29 using appropriate polarization-influencing optical elements, such as for example a polarization rotation unit as described in WO 2006/040184 A2 or a rotatable λ/2 plate as disclosed, for example, in WO 2005/027207 A1, which are arranged in the modules 28 , 29 or in the beam direction after these modules, for example in time correlation with the scanning process.
Polarization-influencing optical elements as presented, for example, in WO 2006/040184 A2 can allow relatively fast changes in the polarization characteristic within the two modules 28 , 29 . The disclosure therefore provides the flexibility to illuminate chip structures or combinations of differing chip structures of wafer partial regions, for example during the scanning process, with intensity illumination settings adapted to the requirements for imaging and/or spatial polarization distributions in the pupil plane of the projection exposure apparatus for imaging which is optimised with regard to contrast and resolution. For chip manufacturers, this can open up new possibilities for arranging differing chip structures on a wafer, as the disclosure allows combination of chip structures which, owing to the various requirements placed on the necessary illumination settings, may have been previously avoided on a single wafer or may have been imaged only with relatively high integration density.
With the foregoing embodiments, it is equally possible to provide, using the at least two optical modules 28 , 29 , a single intensity illumination setting even with the same spatial polarization distribution, i.e. two illumination settings which are similar within predetermined tolerances, in the pupil plane 12 . This is, for example, advantageous if during the scanning process double exposure with two differing settings and/or differing polarization states would be inappropriate for specific partial regions of a chip, for the high-contrast imaging of chip structures into the partial region.
A further potential advantage of operating the two optical modules 28 , 29 with identical illumination settings and identical spatial polarization distributions in the pupil plane 12 is that, on switching during the light pulse according to the switching-time example in FIG. 3 , the peak load or, on switching between the light pulses according to the switching-time example in FIG. 2 , the permanent load on the optical components in the two optical modules 28 , 29 is reduced compared to operation of an identical illumination setting with the same polarization distribution in a conventional illumination system or compared to operation of the illumination setting in merely one of the two optical modules 28 , 29 .
FIGS. 18 to 29 specify examples of combinations of differing illumination settings in the pupil plane 12 with associated mask structures. The examples specified in FIGS. 18 , 19 , 22 , 23 , 26 and 27 are merely a small selection of the illumination settings achievable by the disclosure.
The terms “sigma inner (inner σ)”, “sigma outer (outer σ)” and “polar width” will be used hereinafter for the purposes of characterization. The inner σ is in this case defined as the pupil radius in which 10% of the illumination light intensity is in the pupil. The outer σ is in this case defined as the pupil radius in which 90% of the illumination light intensity is in the pupil. The polar width is defined as the opening angle between radii which delimit a structure illuminated in the pupil plane and at which the intensity has fallen to 50% of the maximum intensity of this structure.
FIG. 18 shows an illumination setting in the form of dipole illumination in the X-direction having a polar width of 35°, an inner σ of 0.8 and an outer σ of 0.99. FIG. 19 shows a further illumination setting in the form of a dipole illumination in the Y-direction having a polar width of 35°, an inner σ of 0.3 and an outer σ of 0.5. The illumination setting in FIG. 18 can in this case be provided by the module 28 and the illumination setting in FIG. 19 by the module 29 or vice versa. If these illumination settings are to be operated in a polarized manner, it is advantageous if the illumination setting in FIG. 18 is polarized linearly in the Y direction. The polarization direction of the illumination setting in FIG. 19 is in this case not crucial for the imaging contrast as owing to the maximum outer σ of 0.5 the light beams strike the wafer while still at moderate angles in contrast to the illumination setting in FIG. 18 .
FIGS. 20 and 21 show exemplary mask structures that can be illuminated and imaged with good imaging quality during a scanning process by double exposure or change-over of the illumination settings in FIGS. 18 and 19 provided by the optical modules 28 , 29 . The mask structure in FIG. 20 is in the form of thick vertical lines having an extension in the Y direction of 50 nm wide and a 50 nm spacing between the lines in the X direction. The mask structure in FIG. 21 is in the form of horizontal and vertical lines having a width greater than 100 nm. In the latter case, the lines are said to be isolated. The simultaneous imaging of structures in FIGS. 20 and 21 is a typical application in which on a mask in one direction relatively low width structures and at the same time in the same direction or perpendicularly thereto relatively non-low width structures are to be transferred via illumination onto the wafer. Depending on whether on a mask the aforementioned thick and isolated lines from FIGS. 20 and 21 are formed adjacently to or set apart from one another, the double exposure or the change-over or a mixture of double exposure and change-over of the illumination settings in FIGS. 18 and 19 , correlated with the scanning process, will prove to be optimal for imaging the mask structures of FIGS. 20 and 21 . The illumination setting in FIG. 18 is suitable for the high-contrast imaging of a mask having exclusively thick lines corresponding to the mask structure in FIG. 20 and the illumination setting in FIG. 19 is suitable for high-contrast imaging of a mask having exclusively isolated lines corresponding to the mask structure in FIG. 21 .
FIG. 22 shows an illumination setting in the form a quasar or quadrupole illumination having poles with 35° polar width along the diagonal between the X and Y direction with an inner σ of 0.8 and an outer σ of 0.99. FIG. 23 shows an illumination setting in the form of a conventional illumination with an outer σ of 0.3. The illumination setting in FIG. 22 can in this case be provided by the module 28 and the illumination setting in FIG. 23 by the module 29 or vice versa. If these illumination settings are to be operated in a polarized manner, it is advantageous if the illumination setting in FIG. 22 is linearly polarized tangentially to the optical axis. The foregoing remarks concerning the polarization direction of the illumination setting in FIG. 19 accordingly apply to the polarization direction of the illumination setting in FIG. 23 .
FIGS. 24 and 25 show mask structures which are to be provided by double exposure or change-over of the illumination settings in FIGS. 22 and 23 during a scanning process. These structures are relatively high packing density ( FIG. 24 ) and relatively non-high packing density ( FIG. 25 ) contact holes having a width of, for example, 65 nm. Depending on whether on a mask the aforementioned high packing density contact holes and non-high packing density contact holes from FIGS. 24 and 25 are formed adjacent to or set apart from one another, the double exposure or change-over or a mixture of double exposure and change-over of the illumination settings in FIGS. 22 and 23 , correlated with the scanning process, will be found to be optimal for imaging the mask structures from FIGS. 24 and 25 . The illumination setting in FIG. 22 is suitable for the high contrast imaging of a mask having exclusively relatively high packing density contact holes corresponding to the mask structure of FIG. 24 and the illumination setting in FIG. 23 can be best suited for the high-contrast imaging of a mask having exclusively non-high packing density contact holes corresponding to the mask structure of FIG. 25 .
FIG. 26 shows an illumination setting in the form of an X-dipole illumination having poles with 35° polar width in the X direction with an inner σ of 0.8 and an outer σ of 0.99. FIG. 27 shows an illumination setting in the form of a Y-dipole illumination having poles with 35° polar width in the Y direction with an inner σ of 0.8 and an outer σ of 0.99. The illumination setting in FIG. 26 can in this case be provided by the module 28 and the illumination setting in FIG. 27 by the module 29 or vice versa. If these illumination settings are to be operated in a polarized manner, it is advantageous if the illumination setting in FIG. 26 is polarized linearly in the Y direction and the illumination setting in FIG. 27 is polarized linearly in the X direction.
FIGS. 28 , 29 show the two masks which are successively to be imaged onto the same wafer to be illuminated by double exposure with the illumination settings in FIGS. 26 and 27 during two scanning processes. These masks are thick horizontal ( FIG. 28 ) and vertical ( FIG. 29 ) structures having a width of, for example, 50 nm and a line spacing of, for example, 50 nm. In contrast to the foregoing examples, for imaging the two masks in FIGS. 28 , 29 there is carried out a double exposure in which there is carried out on the same wafer to be illuminated, in a first step, a scanning process with the mask in FIG. 28 and the illumination setting in FIG. 26 and, in a second step, a second scanning process with the mask in FIG. 29 and the illumination setting in FIG. 27 . Two different illuminations are thus carried out on the same wafer with the differing masks. This double exposure with the differing masks therefore differs from the double exposure or change-over in a single mask in which merely the illumination setting with which the mask is illuminated is changed. It is also possible in this case for the two separate masks to be arranged next to each other in the reticle or mask plane and to be moved in the scanning direction by component 23 for holding and manipulating the masks or reticles. In this case, there is no need for a complex change of masks between the two illuminations and the masks can be successively transferred onto the same wafer to be illuminated in a single scanning process instead of in two scanning processes carried out in succession. Owing to the high scanning speed of the component 23 , which is responsible for the high wafer throughput of the projection exposure apparatus, it is necessary to change the illumination settings for the two masks very rapidly during transfer of the masks in the one scanning process. In principle, it is not compulsory for the two separate masks to be arranged in the same plane. In principle, the two masks can also be arranged in various planes, the projection exposure apparatus being adapted during the change between the masks arranged in various planes by appropriate and optionally automatic adjustment of optical components.
In all of the above-mentioned illumination settings in FIGS. 18 , 19 , 22 , 23 , 26 and 27 , the double or multiple exposure according to the disclosure of a mask with the two illumination settings in FIGS. 18 and 19 , 22 , 23 , 26 and 27 with switching times of up to 1 ns or the change-over according to the disclosure of the two settings allows precise monitoring and optimization of the light intensity within the two settings. This can allow for the scanning process with a mask structure in FIGS. 20 , 21 , 24 , 25 , 28 and 29 good (e.g., optimum) structures and structure widths to be achieved on the wafer to be illuminated. It is in this case also possible for the two zoom-axicon groups 11 , 31 of the two optical modules 28 , 29 to be controlled over a slower time scale during the scanning process in order to alter the inner and outer minimum or maximum illumination angles, defined by the two respectively utilized illumination settings.
A further potential advantage of operating the at least two optical modules 28 , 29 with identical or differing illumination settings and with identical or differing polarization distributions in the pupil plane 12 is obtained on switching during the light pulse in accordance with the switching-time example in FIG. 3 if, within an optical module 28 or 29 , use is made of an optical component 80 which delays the partial light pulse of the module (see FIG. 17 ). The optical component 80 may, for example, consist of a correspondingly folded optical delay line, of at least two mirrors or of corresponding equivalents which allow the light propagation time to be extended. Switching during the light pulse in accordance with the switching-time example in FIG. 3 allows, as stated hereinbefore, a laser having an output with a repetition rate of 12 kHz to be produced from a laser having a repetition rate of, for example, 6 kHz. The optical component 80 in FIG. 17 then delays the partial light pulse of the illumination light in the optical module 29 in relation to the other partial light pulse of the illumination light in the other optical module 28 with regard to the light propagation time in such a way that, for example, the partial light pulses from the one module 28 are mutually time-shifted with respect to the partial light pulses from the other module in such a way that chronologically equidistant light pulses arrive on the reticle 19 to be illuminated. In this case, the light pulses L 1 , L 2 are time-delayed by the interval of adjacent laser pulses L at the location at which they were separated at the switching instant t s , so all the laser pulse parts L 1 , L 2 generated by the switching are at the same intervals from one another after the coupling element. Thus, for example, not only can a 6 kHz laser be split up to form a 12 kHz laser, the dose per time interval of the split 12 kHz laser can, for example, also be controlled so as substantially to correspond to the dose per time interval of a real 12 kHz laser. This is important for a scanning process with pulsed light sources, as it has to be ensured that each partial region of a chip is given the same dose of light during the scanning process. If, as mentioned hereinbefore, the two modules 28 , 29 are operated proportionally, i.e. with, in their dose, differing partial light pulses in the period of time and/or with varying intensity, a chronologically non-equidistant pulse sequence of the light pulses arriving on the reticle 19 from the two modules 28 , 29 may be beneficial with regard to the dose.
It should be noted that the above-mentioned polarization setting within the two optical modules 28 , 29 or thereafter is not only beneficial with regard to the adjustment of the spatial polarization distribution in the pupil plane 12 for the respective illumination settings, as for example in FIG. 18 , 19 , 22 , 23 , 26 or 27 ; it is also beneficial to preserve a certain polarization state which is varied by the two optical modules 28 , 29 themselves, the subsequent lens system, the reticle 19 , the projection objective 20 and/or by a photoresist layer of the wafer 24 to be illuminated. It is thus possible to provide on the wafer 24 the polarization state respectively required for high-contrast imaging even if the polarization state changes in the light path from the polarization-influencing optical elements to the wafer 24 . This preservation of a spatial polarization distribution may also prove beneficial only during operation of a projection exposure apparatus if, owing to slow changes in the optical characteristics of the optical elements of the illumination system 5 , the projection objective 20 and the reticle 19 , these optical elements alter the polarization state of the light passing therethrough. Slow changes of this type may, for example, be brought about by thermal drifts.
As an alternative to switching the polarization using a Pockels cell 8 ; 39 or a Kerr cell, use may also be made of a magneto-optic switch based on the Faraday effect.
As an alternative to the aforementioned switching or decoupling using the light wavelength as the exchangeable light characteristic, Raman cells, as described in U.S. Pat. No. 4,458,994, or Bragg cells, as described in U.S. Pat. No. 5,453,814, may be used. U.S. Pat. No. 4,458,994 and U.S. Pat. No. 5,453,814 are hereby incorporated by reference. Use may be made for this purpose of a photoelastic modulator (PEM) such as is described, for example, in US 2004/0262500 A1, which is hereby incorporated by reference.
As an alternative to the aforementioned possible switching or decoupling elements, use may also be made of combinations of the aforementioned options, especially combinations in which at least one component operates of the basis of an electro-optical or magneto-optical principle.
Other embodiments are in the claims. | Optics, such as, for example, microlithographic projection exposure apparatus illumination optics, as well as related systems, methods, components and devices are disclosed. | 6 |
FIELD OF THE INVENTION
The present invention relates to a spring winding device, such as for use in pretensioning a counterbalance spring used with an overhead door.
BACKGROUND OF THE INVENTION
Conventionally, a torsion spring counterbalancing mechanism may be used with an overhead door to counterbalance a weight of the overhead door when moving the overhead door during between an open position and a closed position. When the torsion spring counterbalancing mechanism is installed, one or more springs forming a portion of the torsion spring counterbalancing mechanism need to be pretensioned with an amount of counterbalancing force. Further, following initial installation, adjustment of the amount of counterbalancing force may be necessary to repair or replace the torsion spring counterbalancing mechanism.
A conventional method used to adjust the amount of counterbalancing force in one or more springs forming a portion of the torsion spring counterbalancing mechanism may be dangerous. Winding rods are typically inserted into a spring end cone, a rotational force is applied to the one or more springs, the spring end cone is disengaged from a torsion shaft, and the amount of counterbalancing force is one of increased and decreased. When a first winding rod is inserted in the spring end cone, the rotational force may be applied to the one or more springs. Using a second winding rod and an iterative process, the one or more springs may be wound or unwound. Such a process may be dangerous, as the winding rod will rotate quickly when the one or more springs are pretensioned and the winding bar is unrestrained.
To reduce such a danger, it is known in the prior art to employ a spring winder having a worm drive gear engaged with a worm wheel to adjust the amount of counterbalancing force. The worm wheel is fitted about a center portion of the torsion shaft and the worn drive gear is rotated to adjust the amount of counterbalancing force in the one or more springs. However, when the one or more springs are pretensionsed, the worm wheel may tilt or move along its axis as it resists the counterbalancing force. When the worn wheel tilts or moves along its axis, the worn drive gear may become disengaged or misaligned, rendering such a spring winder inoperable.
It is also known in the prior art to locate the spring winder having the worm drive gear engaged with the worm wheel at an end of the torsion shaft to militate against movement of the worm wheel. In such an arrangement a separate spring winder is employed for each spring, and the spring winder is subject to a thrust force of the spring. Balancing the thrust force of the spring may extend a service life of the spring significantly. Further, in such an arrangement, non-conventional cable drums are employed to house a portion of the spring winder. The spring winder having the worm wheel at an end of the torsion shaft increases a cost and a complexity of the counterbalancing mechanism while decreasing a service life of the one or more springs.
It would be advantageous to develop a spring winding device that does not require pretensioning using winding rods, maintains rigidity and alignment when a counterbalancing force is applied, and decreases a cost and a complexity of a counterbalancing mechanism the spring winding device is incorporated in.
SUMMARY OF THE INVENTION
Presently provided by the invention, a driveline including a continuously variable transmission that is inexpensive, compact, may be configured for a wide range of torque distributions, and able to adjust a drive ratio has surprisingly been discovered.
In one embodiment, the present invention is directed to a spring winding device for a counterbalancing mechanism. The spring winding device comprises a support bracket, a worm gear, and a drive gear. The worm gear is rotatably coupled to the support bracket and includes a mount portion for coupling a first end cone thereto. The drive gear is rotatably disposed adjacent the support bracket and is drivingly engaged with the worm gear. A rotation of the drive gear causes the worm gear to rotate within the support bracket.
In another embodiment, the present invention is directed to a counterbalancing force adjustment device for a counterbalancing mechanism. The counterbalancing force adjustment device comprises an anti-rotation device and a spring winding device. The anti-rotation device comprises an elongate member and a bumper portion. The bumper portion is coupled to the elongate member. The spring winding device comprises a support bracket, a worm gear, and a drive gear. The worm gear is rotatably coupled to the support bracket. The worm gear includes a mount portion for coupling a first end cone thereto. The drive gear is rotatably disposed adjacent the support bracket. The drive gear is drivingly engaged with the worm gear. The anti-rotation device is drivingly engaged with a second end cone to militate against a rotation thereof. A rotation of the drive gear causes the first end cone to rotate with the worm gear, causing an amount of counterbalancing force stored in a torsion spring coupled to the first end cone and the second end cone to be adjusted.
In another embodiment, the present invention is directed to a method of adjusting an amount of force stored in a pair of springs of a counterbalancing mechanism. The method comprises the steps of providing a first spring disposed about a shaft, the first spring and shaft forming a portion of the counterbalancing mechanism, the first spring drivingly engaged with the shaft at a first end thereof; providing a second spring disposed about the shaft, the second spring and shaft forming a portion of the counterbalancing mechanism, the second spring drivingly engaged with the shaft at a first end thereof; providing a spring winding device for the counterbalancing mechanism, the spring winding device comprising a rotatable portion for coupling a second end of the first spring and a second end of the second spring thereto; and adjusting the amount of force stored in the pair of springs of the counterbalancing mechanism simultaneously by rotating the rotatable portion of the spring winding device.
In another embodiment, the present invention is directed to a method of adjusting an amount of force stored in a spring of a counterbalancing mechanism. The method comprises the steps of providing the spring disposed about a shaft having a keyway formed therein, the spring and shaft forming a portion of the counterbalancing mechanism, the spring drivingly engaged with the shaft at a first end thereof through the use of a keyed mounting cone, the keyed mounting cone able to be moved along the keyway of the shaft; providing a spring winding device for the counterbalancing mechanism, the spring winding device comprising a rotatable portion for coupling a second end of the first spring and a second end of the second spring thereto; and adjusting the amount of force stored in the counterbalancing mechanism by rotating the rotatable portion of the spring winding device, wherein in response to the amount of force stored in the counterbalancing mechanism being adjusted, a position of the keyed mounting cone moves along the shaft as a length of the spring changes.
In another embodiment, the present invention is directed to a method of adjusting an amount of force stored in a spring of a counterbalancing mechanism. The method comprises the steps of providing the spring disposed about a shaft, the spring and shaft forming a portion of the counterbalancing mechanism, the spring drivingly engaged with the shaft at a first end thereof; providing a spring winding device for the counterbalancing mechanism, the spring winding device comprising a support bracket, a worm gear rotatably coupled to the support bracket, the worm gear including a mount portion for coupling a second end of the spring thereto, and a drive gear rotatably disposed adjacent the support bracket, the drive gear drivingly engaged with the worm gear, wherein a rotation of the drive gear causes the worm gear to rotate within the support bracket; providing an anti-rotation device comprising an elongate member and a bumper portion, the bumper portion coupled to the elongate member; drivingly engaging the anti-rotation device with the first end of the spring; releasing the first end of the spring from driving engagement with the shaft; adjusting the amount of force stored in the counterbalancing mechanism by rotating the drive gear; drivingly engaging the first end of the spring with the shaft; and releasing the anti-rotation device from driving engagement with the first end of the spring.
Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:
FIG. 1 is a perspective view of a spring winding device according to an embodiment of the present invention;
FIG. 1A is a side view of an end cone and a torsion shaft according to another embodiment of the present invention;
FIG. 2 is a perspective view of the spring winding device shown in FIG. 1 ;
FIG. 3 is a perspective view of the spring winding device shown in FIG. 1 ;
FIG. 4 is a perspective view of the spring winding device shown in FIG. 1 ;
FIG. 5 is a perspective view of a gear shroud used with the spring winding device shown in FIG. 1 ;
FIG. 6 is a perspective view of an anti-rotation device according to an embodiment of the present invention;
FIG. 7 is a perspective view of an anti-rotation device according to another embodiment of the present invention;
FIG. 8 is a perspective view of an anti-rotation device according to another embodiment of the present invention;
FIG. 9 is a perspective view of an anti-rotation device according to another embodiment of the present invention;
FIG. 10 is a perspective view of an anti-rotation device according to another embodiment of the present invention; and
FIG. 11 is a perspective view of the spring winding device shown in FIG. 1 including the gear shroud shown in FIG. 5 , the spring winding device being used with the anti-rotation device shown in FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
FIGS. 1, 2, 3, 4 and 11 illustrate a spring winding device 10 according to an embodiment of the invention. The spring winding device 10 forms a portion of a counterbalancing mechanism (partially shown) for an overhead door (not shown) and preferably comprises a support bracket 12 , a flanged worm gear 14 , a drive gear assembly 15 , and a gear shroud 16 (shown in FIGS. 5 and 11 ). As shown, the spring winding device 10 is mounted above the overhead door placed in a closed position. As a non-limiting example, the overhead door may be a residential garage door.
The counterbalancing mechanism also includes two torsion springs 17 and a torsion shaft 18 . Each of the torsion springs 17 include a first end cone 19 and a second end cone 20 fixed to opposing ends of the torsion spring 17 . Each of the first end cones 19 as shown is known in the art as a winding cone, and may be coupled to the torsion shaft 18 using at least one set screw 21 . Each of the second end cones 20 as shown is known in the art as a stationary cone, and is coupled to the flanged worm gear 14 using at least one fastener. The spring winding device 10 is disposed about the torsion shaft 18 , which also forms a portion of the counterbalancing mechanism. The torsion shaft 18 is a conventional torsion shaft, and is well known in the art.
As shown in FIGS. 1 and 11 , the torsion shaft 18 is a torsion shaft having a keyway 22 formed therein. The keyway 22 formed therein may be disposed through a keyed end cone 19 ′ having a key 23 formed thereon, shown in FIG. 1A . The keyed end cone 19 ′ having the key 23 is drivingly engaged with the keyway 22 of the torsion shaft 18 . The keyed end cone 19 ′ is able to be moved along a length of the torsion shaft 18 while maintaining driving engagement with the torsion shaft 18 . The keyed end cone 19 ′ is able to move along the torsion shaft 18 as an amount of counterbalancing force stored in each of the torsion springs 17 coupled thereto is adjusted. It is understood that when the amount of counterbalancing force stored in each of the torsion springs 17 is adjusted, a length of each of the torsion springs 17 changes. In response to the length of each of the torsion springs 17 changing, each of the keyed end cones 19 ′ moves along the torsion shaft 18 . The keyed end cone 19 ′ having the key 23 formed thereon eliminates a need for an anti-rotation device when an amount of counterbalancing force stored in each of the torsion springs 17 is adjusted. The keyed end cone 19 ′ militates against a binding that may occur to the torsion springs 17 if the amount of counterbalancing force stored in each of the torsion springs 17 is adjusted without allowing the length of each of the torsion springs 17 to change.
The support bracket 12 is a L-shaped member mounted to a wall 24 above a frame (not shown) for the overhead door. The support bracket 12 includes a mounting portion 25 and a main portion 26 . A retaining portion 27 is coupled to the support bracket 12 . A drive gear assembly aperture 28 , a flanged worm gear fastening perforation 29 , and a plurality of mounting apertures 30 are formed through the main portion 26 and the mounting portion 25 . A portion of an outer peripheral edge of the main portion 26 and a portion of an outer peripheral edge of the retaining portion 27 define a torsion shaft perforation 32 . The support bracket 12 is preferably formed by stamping and bending a sheet metal such as steel; however, it is understood that the support bracket may be formed with other processes from other materials.
The mounting portion 25 has a rectangular shape and includes at least two mounting apertures 30 formed therethrough. As most clearly shown in FIG. 2 , the mounting apertures 30 may be circular apertures or elongate apertures. A plurality of fasteners, such as screws, bolts, or the like, is disposed through the mounting apertures 30 and couple the support bracket 12 to the wall 24 . It is understood that the mounting portion 25 may include a bracket adjustment device (not shown). The bracket adjustment device allows a position of the support bracket with respect to the wall 24 to be adjusted. The bracket adjustment device facilitates installation and service of the counterbalancing mechanism the spring winding device 10 forms a portion of.
The main portion 26 is an elongate portion of the support bracket 12 and includes the drive gear assembly aperture 28 formed therethrough. As most clearly shown in FIG. 3 , the drive gear assembly aperture 28 is substantially rectangular in shape and also defines an alignment tab 34 and a drive gear retention tab 36 . Alternately, the drive gear assembly aperture 28 may be any other shape. The alignment tab 34 is an elongate member bent away from and substantially orthogonal to a surface of the main portion 26 . The drive gear retention tab 36 is an elongate member bent away from and substantially orthogonal to a surface of the main portion 26 . The drive gear retention tab 36 is formed adjacent the alignment tab 34 and is bend in an opposing direction with respect to the alignment tab 34 . At least one flanged worm gear fastening perforation 29 is formed through the main portion 26 . The flanged worm gear fastening perforation 29 is an elongate perforation; however, it is understood that that flanged worm gear fastening perforation 29 may have another shape. As mentioned hereinabove, a portion of the outer peripheral edge of the main portion 26 partially defines the torsion shaft perforation 32 . The torsion shaft perforation 32 is substantially circular in shape.
The retaining portion 27 is a member coupled to the main portion 26 . As shown in FIGS. 1-3 and 11 , the retaining portion 27 is coupled to the main portion 26 using a plurality of rivets disposed through perforations formed through the main portion 26 and the retaining portion 27 ; however it is understood that the retaining portion 27 may be coupled to the main portion 26 using any conventional fastener. As mentioned hereinabove, a portion of the outer peripheral edge of the retaining portion 27 partially defines the torsion shaft perforation 32 . The retaining portion 27 is preferably formed by stamping and bending a sheet metal such as steel; however, it is understood that the support bracket 12 may be formed with other processes from other materials.
The flanged worm gear 14 is a disposed between the main portion 26 and the retaining portion 27 , through the torsion shaft perforation 32 . When not coupled to the support bracket 12 , the flanged worm gear 14 is a rotatable portion of the spring winding device 10 . The flanged worm gear 14 includes a gear portion 38 and a first end cone mount portion 40 . A support recess 42 is formed between the gear portion 38 and the first end cone mount portion 40 . A torsion shaft aperture 44 is formed through the flanged worm gear 14 . The flanged worm gear 14 is formed by casting and machining a metal; however, it is understood that other processes may be used to form the flanged worm gear 14 .
The gear portion 38 is a disc shaped member having a toothed outer edge 46 . The toothed outer edge 46 of the gear portion 38 is in driving engagement with the drive gear assembly 16 . A plurality of set perforations 48 are formed through the gear portion 38 . Each of the set perforations 48 may be aligned with the flanged worm gear fastening perforation 29 when the flanged worm gear 14 is rotated about a gear portion axis. A fastener 49 is disposed through the flanged worm gear fastening perforation 29 and one of the set perforations 48 to couple the flanged worm gear 14 to the support bracket 12 . As shown in FIGS. 1, 2, 3, 4 and 11 , the fastener 49 is a fastener having threads corresponding to threads formed in the set perforations 48 ; however, it is understood that the fastener 49 may be any conventional fastener. The gear portion axis is substantially coincident to an axis of the torsion shaft 18 . At least two cone mounting perforations 50 are formed in a second end cone mount portion 51 . The second end cone mount portion 51 comprises two protuberances extending away from the gear portion 38 ; however, it is understood that the second end cone mount portion 51 may comprise other shapes or that the gear portion 38 may not include the second end cone mount portion 51 . Preferably, the cone mounting perforations 50 are threaded, however, it is understood that the cone mounting perforations 50 may be configured for any type of fastener.
The first end cone mount portion 40 is a flanged shape member spaced apart from the gear portion 38 . As most clearly shown in FIG. 3 , the first end cone mount portion 40 includes a hollow central cylindrical portion 52 and two radially extending protuberances 54 . At least two cone mounting perforations 56 are formed in the radially extending protuberances of the first end cone mount portion 40 . Preferably, the cone mounting perforations 56 are threaded, however, it is understood that the cone mounting perforations 56 may be configured for any type of fastener.
As shown in FIGS. 1-3 and 11 , when the counterbalancing mechanism including the spring winding device 10 is in an installed condition, each of the second end cones 20 is coupled to the end cone mount portion 40 and the second end cone mount portion 51 using fasteners inserted through each of the second end cones 20 and into the cone mounting perforations 50 , 56 . Alternately, it is understood that the second end cones 20 may be integrally formed with the gear portion 38 or coupled to the gear portion 38 in any other conventional manner.
The support recess 42 is a recess between the gear portion 38 and the two radially extending protuberances 54 . A portion of the first end cone mount portion 40 having a reduced diameter defines the support recess 42 . When the flanged worm gear 14 is disposed in the support bracket 12 , at least a portion of the main portion 26 and the retaining portion 27 enter and rotatably support the flanged worn gear 14 . A width of the support recess 42 is slightly greater than a thickness of the main portion 26 and the retaining portion 27 , permitting the main portion 26 and the retaining portion 27 to be disposed therein. The width of the support recess 42 militates against a substantial axial deviation of the flanged worm gear 14 within the support bracket 12 .
The drive gear assembly 16 is coupled to the main portion 26 of the support bracket 12 . The drive gear assembly 16 includes a drive gear housing 58 and a drive gear 60 . The drive gear housing 58 is coupled to the main portion 26 and the drive gear 60 is rotatably disposed in the drive gear housing 58 . As shown in FIGS. 1, 2, 3, 4 and 11 , the drive gear assembly 16 includes a single drive gear; however, it is understood that the drive gear assembly may include two or more drive gears arranged in a gear train to facilitate adjusting an amount of counterbalancing force in one or more torsion springs.
The drive gear housing 58 is a member formed by casting and machining a metal such as steel; however, it is understood that the drive gear housing 58 may be formed with other processes from other materials. The drive gear housing 58 is disposed in the drive gear assembly aperture 28 and coupled to the main portion 26 . A first drive gear slot 62 and a second drive gear slot 64 are formed in opposing portions of the drive gear housing 58 . The first drive gear slot 62 and the second drive gear slot 64 align and rotatably support the drive gear 60 when the spring winding device 10 is assembled. As most clearly shown in FIGS. 3 and 4 , a plurality of mounting perforations corresponding to mounting perforations formed through the main portion 26 receive rivets to couple the drive gear housing 58 to the main portion 26 . However, it is understood the drive gear housing 58 may be coupled to the main portion 26 in any conventional manner. The drive gear housing 58 also includes an alignment tab 66 extending from a remaining portion of the drive gear housing 58 . When the drive gear housing 58 is coupled to the main portion 26 , the alignment tab 66 is disposed through the drive gear assembly aperture 28 and supported by the main portion 26 . When the drive gear housing 58 is coupled to the main portion 26 , a portion of the drive gear housing 58 is disposed against the alignment tab 34 , as shown in FIGS. 2 and 3 .
The drive gear 60 is a threaded member rotatably disposed in the drive gear housing 58 . When the spring winding device 10 is assembled, at least one thread 68 formed in the drive gear 60 is in driving engagement with the toothed outer edge 46 of the flanged worm gear 14 . The drive gear 60 includes two annular journals 70 which are disposed in the drive gear slots 62 , 64 and militate against axial movement of the drive gear 60 with respect to the drive gear housing 58 . A drive end 72 of the drive gear 60 is disposed adjacent an outer surface of the drive gear housing. As most clearly shown in FIG. 4 , the drive end 72 includes a hexagonal shaped protuberance for drivingly engaging a driving tool (not shown); however, it is understood that the drive end 72 may include other features formed therein for engaging other drive tools. When the driving tool is engaged with the drive end 72 and the driving tool is rotated, the drive gear 60 rotates and the at least one thread 68 applies a force to the toothed outer edge 46 of the flanged worm gear 14 , causing the flanged worm gear 14 to rotate within the support bracket 12 . When the drive gear 60 is disposed in the drive gear housing 58 , a second end 74 of the drive gear 60 is disposed adjacent to or abuts the drive gear retention tab.
As shown in FIGS. 5 and 11 , the gear shroud 16 is a ring shaped member coupled to the support bracket 12 . The gear shroud 16 is formed from a plastic using a molding process; however, it is understood that the gear shroud 16 may be formed from other materials using other processes. The gear shroud 16 has a substantially L-shaped cross-section and encloses at least a portion of the flanged worm gear 14 . Further, it is understood that the gear cover may enclose at least a portion of the drive gear assembly 16 . It is also understood that the gear cover may form a portion of a torsion spring cover (not shown). The gear shroud 16 includes a plurality of shroud fasteners 76 and a drive gear protuberance 78 . The gear shroud 16 militates against debris from collecting on or within the toothed outer edge 46 , the drive gear housing 58 , the drive gear 60 . Further, the gear shroud 16 militates against an entanglement that may occur between a foreign object, the toothed outer edge 46 , and the drive gear 60 .
Each of the shroud fasteners 76 is a hollow, bifurcated protuberance having a barbed end. Each of the shroud fasteners correspond to a shroud perforation 80 formed in one of the main portion 26 and the retaining portion 27 of the support bracket 12 . An elastic deformation of each of the shroud fasteners 76 allows each of the shroud fasteners 76 to be disposed in the shroud perforation 80 , coupling the gear shroud 16 to the support bracket 12 .
The drive gear protuberance 78 is a portion of the gear shroud 16 extending away from a remaining portion of the gear shroud 16 . The drive gear protuberance 78 has a substantially rectangular shape; however, it is understood that the drive gear protuberance 78 may have other shapes or may be formed separate from the remaining portion of the gear shroud 16 . When the gear shroud 16 is coupled to the support bracket 12 , the drive gear protuberance 78 is disposed adjacent or abuts the drive gear housing 58 .
FIG. 6 illustrates an anti-rotation device 100 for use with each of the first end cones 19 . The anti-rotation device 100 may be used with the spring winding device 10 when the counterbalancing mechanism is installed or serviced. The anti-rotation device 100 is coupled to each of the first end cones 19 to resist a torque applied to the first end cones 19 when a tension of the torsion spring 17 is adjusted during installation or service of the counterbalancing mechanism. When the tension of the torsion spring 17 is adjusted during installation or service of the counterbalancing mechanism, the anti-rotation device 100 permits the first end cones 19 to move along the torsion shaft 18 to accommodate changes in length of the torsion spring 17 that occur during adjustment of the tension of the torsion spring 17 . As shown in FIGS. 1, 2, and 11 , the counterbalancing mechanism comprises two torsion springs, disposed on opposite sides of the spring winding device 10 , and would require the use of two anti-rotation devices 100 to install or service the counterbalancing mechanism. FIG. 11 illustrates an anti-rotation device 100 ″ according to another embodiment of the invention being used to install or service the counterbalancing mechanism.
As shown in FIGS. 1, 2, and 6-11 , the first end cone 19 includes apertures 102 formed therein oriented transversely to a torsion shaft aperture 104 . The first end cone 19 includes four apertures 102 formed therein, the apertures 102 spaced apart equally. The at least one set screw 21 is threadingly disposed in the first end cone 19 for coupling the first end cone 19 to the torsion shaft 18 . The first end cone 19 is a conventional winding cone, and is well known in the art.
The anti-rotation device 100 includes a main body 108 , an arm member 110 , and a first cone pin 112 . The arm member 110 and the first cone pin 112 are adjustably disposed within the main body 108 . When the anti-rotation device 100 is coupled to the first end cone 19 , the anti-rotation device 100 is in driving engagement therewith.
The main body 108 is a L-shaped member the arm member 110 and the first cone pin 112 are adjustably disposed within. The main body 108 includes a first leg 114 , a second leg 116 , a second cone pin 118 , and at least one arm member fastener 120 . An arm member perforation 122 is formed through the first leg 114 and a cone pin perforation 124 is formed through the second leg 116 . The main body 108 is formed by casting and machining a metal; however, it is understood that other processes may be used to form the main body 108 .
The first leg 114 is an elongate member having a rectangular cross section. The arm member perforation 122 is formed lengthwise through the first leg 114 and has a diameter which permits the arm member 110 to be disposed therethrough. The at least one arm member fastener 120 is threadingly disposed in a perforation that intersects the arm member perforation 122 . When the at least one arm member fastener 120 is driven to engage the arm member 110 disposed in the arm member perforation 122 , the arm member 110 is coupled to the main body 108 . The second cone pin 118 extends outwardly from the first leg 114 and is coupled thereto in any conventional manner. A diameter of the second cone pin 118 substantially corresponds to the apertures 102 of the first end cone 19 .
The second leg 116 is an elongate member having a rectangular cross section. The second leg 116 is oriented transversely to the first leg 114 . The cone pin perforation 124 is formed through the second leg 116 transverse to the second cone pin 118 and has a diameter which permits the first cone pin 112 to be disposed therethrough. The first cone pin 112 is disposed through the cone pin perforation 124 and extends outwardly from the second leg 116 and is removably coupled thereto by a head 126 of the first cone pin 112 and a pin 128 removably disposed through a perforation in the first cone pin 112 ; however, it is understood that the first cone pin 112 may be removably coupled to the second leg 116 in any conventional manner. The first cone pin 112 includes a plurality of perforations formed therethrough, which permit a length of the first cone pin 112 extending through the cone pin perforation 124 to be adjusted by moving a location of the pin 128 . A diameter of the first cone pin 112 substantially corresponds to the apertures 102 of the first end cone 19 .
The arm member 110 is an elongate member having a shaft portion 130 and a bumper portion 132 . The shaft portion 130 has a circular cross section and is rotatably coupled to the bumper portion 132 at a first end thereof. The shaft portion 130 is formed by forging a metal; however, it is understood that other processes may be used to form the shaft portion 130 . The bumper portion 132 is a disc shaped member rotatably coupled to a distal end of the shaft portion 130 . At least a portion of the bumper portion 132 is formed from a resilient material, such as rubber. However, it is understood that the bumper portion 132 may have other shapes and may be formed from other materials.
FIG. 7 shows an alternative embodiment of the anti-rotation device 100 . Similar structural features of the anti-rotation device 100 include the same reference numeral and a prime (′) symbol.
An anti-rotation device 100 ′ includes a main body 208 , an arm member 210 , and a first cone pin 112 ′. The arm member 210 and the first cone pin 112 ′ are adjustably disposed within the main body 208 . When the anti-rotation device 100 ′ is coupled to the first end cone 19 , the anti-rotation device 100 ′ is in driving engagement therewith.
The main body 208 is a L-shaped member the arm member 210 and the first cone pin 112 ′ are adjustably disposed within. The main body 208 includes a first leg 214 , a second leg 116 ′, a second cone pin 118 ′, and an arm member pin 234 . An arm member perforation 222 is formed through the first leg 214 and a cone pin perforation 124 ′ is formed through the second leg 116 ′. The main body 208 is formed by casting and machining a metal; however, it is understood that other processes may be used to form the main body 208 .
The first leg 214 is an elongate member having a rectangular cross section. The arm member perforation 222 is formed lengthwise through the first leg 214 and has a diameter which permits the arm member 210 to be disposed therethrough. An arm member fastening slot 236 is formed in the first leg 214 , the arm member fastening slot 236 intersecting the arm member perforation 222 . The arm member fastening slot 236 is V-shaped; however, it is understood that other shapes may be used. The arm member pin 234 is disposed in the arm member fastening slot 236 and through one of a series of perforations formed in a shaft portion 230 of the arm member 210 to couple the arm member 210 to the main body 208 . The second cone pin 118 ′ extends outwardly from the first leg 214 and is coupled thereto in any conventional manner. A diameter of the second cone pin 118 ′ substantially corresponds to the apertures 102 of the first end cone 19 .
The second leg 116 ′ is an elongate member having a rectangular cross section. The second leg 116 ′ is oriented transversely to the first leg 214 . The cone pin perforation 124 ′ is formed through the second leg 116 ′ transverse to the second cone pin 118 ′ and has a diameter which permits the first cone pin 112 ′ to be disposed therethrough. The first cone pin 112 ′ is disposed through the cone pin perforation 124 ′ and extends outwardly from the second leg 116 ′ and is removably coupled thereto by a head 126 ′ of the first cone pin 112 ′ and a pin 128 ′ removably disposed through a perforation in the first cone pin 112 ′; however, it is understood that the first cone pin 112 ′ may be removably coupled to the second leg 116 ′ in any conventional manner. The first cone pin 112 ′ includes a plurality of perforations formed therethrough, which permit a length of the first cone pin 112 ′ extending through the cone pin perforation 124 ′ to be adjusted by moving a location of the pin 128 ′. A diameter of the first cone pin 112 ′ substantially corresponds to the apertures 102 of the first end cone 19 .
The arm member 210 is an elongate member having the shaft portion 230 and a bumper portion 132 ′. The shaft portion 230 has a circular cross section and is rotatably coupled to the bumper portion 132 ′ at a first end thereof. The shaft portion 230 includes a plurality of perforations formed therethrough, which permit a length of the shaft portion 230 extending through the arm member perforation 222 to be adjusted by moving a location of the arm member pin 234 . The shaft portion 230 is formed by forging and machining a metal; however, it is understood that other processes may be used to form the shaft portion 230 . The bumper portion 132 ′ is a disc shaped member rotatably coupled to a distal end of the shaft portion 230 . At least a portion of the bumper portion 132 ′ is formed from a resilient material, such as rubber. However, it is understood that the bumper portion 132 ′ may have other shapes and may be formed from other materials.
FIG. 8 shows an alternative embodiment of the anti-rotation device 100 . Similar structural features of the anti-rotation device 100 include the same reference numeral and a double prime (″) symbol.
An anti-rotation device 100 ″ includes two main bodies 340 and an arm member 110 ″. The arm member 110 ″ is adjustably disposed within the main bodies 340 . The main bodies are opposingly disposed on the arm member 110 ″. When the anti-rotation device 100 ″ is coupled to the first end cone 19 , the anti-rotation device 100 ″ is in driving engagement therewith. The anti-rotation device 100 ″ is coupled to the first end cone 19 by moving each of the main bodies 340 along the arm member 110 ″.
Each of the main bodies 340 is a U-shaped member the arm member 110 ″ is adjustably disposed within. The main body 340 includes a fastening portion 342 , a central portion 344 , a cone pin 346 , at least one arm member fastener 348 , and an arm member perforation 350 . The main body 340 is formed by casting and machining a metal; however, it is understood that other processes may be used to form the main body 340 .
The fastening portion 342 is an elongate member having a rectangular cross section. The arm member perforation 350 is formed lengthwise through the fastening portion 342 and has a diameter which permits the arm member 110 ″ to be disposed therethrough. The at least one arm member fastener 348 is threadingly disposed in a perforation that intersects the arm member perforation 350 . When the at least one arm member fastener 348 is driven to engage the arm member 110 ″ disposed in the arm member perforation 350 , the arm member 110 ″ is coupled to the main body 340 . The fastening portion 342 includes an alignment protuberance 352 and an alignment recess 354 .
The alignment protuberance 352 has a rectangular cross-section and extends from the fastening portion 342 in a manner substantially parallel to the arm member perforation 350 . The alignment recess 354 is formed in the fastening portion 342 and has a substantially rectangular cross-section. A shape of the alignment recess 354 corresponds to at least a portion of the alignment protuberance 352 . When two of the main bodies 340 are opposingly disposed on the arm member 110 ″, the main bodies may be positioned so that the alignment protuberances 352 and alignment recesses 354 respectively engage one another, militating against relative rotational movement therebetween about the arm member 110 ″.
The central portion 344 is an elongate member having a rectangular cross section. The central portion 344 is oriented transversely to the fastening portion 342 . The cone pin 346 extends from a distal end of the central portion 344 .
The cone pin 346 is integrally formed with the central portion 344 , has a substantially circular cross-section and extends outwardly from the central portion 344 and is substantially parallel to the fastening portion 342 . Alternately, the cone pin 346 may be coupled to the central portion 344 in any conventional manner. A diameter of the cone pin 346 substantially corresponds to the apertures 102 of the first end cone 19 .
FIG. 9 shows an alternative embodiment of the anti-rotation device 100 . Similar structural features of the anti-rotation device 100 include the same reference numeral and a triple prime (′″) symbol.
An anti-rotation device 100 ′″ includes an adjuster body 456 , a support body 458 , and an arm member 410 . The arm member 410 is adjustably disposed within the adjuster body 456 and the support body 458 . When the anti-rotation device 100 ″ is coupled to the first end cone 19 , the anti-rotation device 100 ′″ is in driving engagement therewith. The anti-rotation device 100 ′″ is coupled to the first end cone by moving the arm member 410 through an adjuster perforation 460 and by disposing an adjuster fastener 462 through the adjuster body 456 .
The adjuster body 456 is a U-shaped member the arm member 410 is adjustably disposed within. The adjuster body 456 includes a primary portion 464 and a secondary portion 466 . The adjuster body 456 is formed by coupling the primary portion 464 to the secondary portion 466 with a plurality of fasteners; however, it is understood that the adjuster body may be unitarily formed.
The primary portion 464 is a L-shaped member. The primary portion 464 includes the adjuster perforation 460 formed therein at a first distal end and a perforation for receiving the adjuster fastener 462 formed therein at a second distal end. The adjuster perforation 460 includes a thread formed thereon, which is engaged with a corresponding thread formed on a shaft portion 468 of the arm member 410 .
The secondary portion 466 is a L-shaped member. The secondary portion 466 includes a cone pin 470 extending therefrom at a first distal end and a perforation for receiving the adjuster fastener 462 formed therein at a second distal end. The cone pin 470 is coupled to the secondary portion 466 and has a substantially circular cross-section and extends outwardly from the secondary portion and is substantially coincident with the shaft portion 468 of the arm member 410 . Alternately, the cone pin 470 may be coupled to the secondary portion 466 in any conventional manner. A diameter of the cone pin 470 substantially corresponds to the apertures of the first end cone.
The support body 458 is a L-shaped member. The support body 458 is coupled to the primary portion 464 at a first distal end and includes a perforation formed therethrough for receiving the shaft portion 468 at a second distal end. The perforation formed through the support body 458 is substantially aligned with the adjuster perforation 460 . The support body 458 is preferably welded to the primary portion 464 ; however, it is understood that the support body 458 may be integrally formed with the primary portion 464 or coupled thereto in any conventional manner.
The arm member 410 is an elongate member having the shaft portion 468 and a bumper portion 132 ′″. The shaft portion 468 is a threaded rod and is rotatably coupled to the bumper portion 132 ′″ at a first end thereof. A diameter of the shaft portion 468 substantially corresponds to the apertures 102 of the first end cone 19 and a second end thereof may be disposed in the apertures 102 . The shaft portion 468 is threadingly disposed through the adjuster perforation 460 and may be secured thereto with a fastener such as a nut, for example. The shaft portion 468 is formed by forging a metal; however, it is understood that other processes may be used to form the shaft portion 468 . The bumper portion 132 ′″ is a disc shaped member rotatably coupled to a distal end of the shaft portion 468 . At least a portion of the bumper portion 132 ′″ is formed from a resilient material, such as rubber. However, it is understood that the bumper portion 132 ′″ may have other shapes and may be formed from other materials.
FIG. 10 shows an alternative embodiment of the anti-rotation device 100 . Similar structural features of the anti-rotation device 100 include the same reference numeral and a quadruple prime (″″) symbol.
The anti-rotation device 100 ″″ includes two main bodies 540 and an arm member 110 ″″. The arm member 110 ″″ is adjustably disposed within the main bodies 540 . The main bodies are opposingly disposed on the arm member 110 ″″. When the anti-rotation device 100 ″″ is coupled to the first end cone 19 , the anti-rotation device 100 ″″ is in driving engagement therewith. The anti-rotation device 100 ″″ is coupled to the first end cone 19 by moving each of the main bodies 540 along the arm member 110 ″″.
Each of the main bodies 540 is a L-shaped member the arm member 110 ″″ is adjustably disposed within. The main body 540 includes a fastening portion 542 , a central portion 544 , a cone pin 546 , and at least one arm member fastener 548 . The main body 540 is formed by casting and machining a metal; however, it is understood that other processes may be used to form the main body 540 .
The fastening portion 542 is a substantially cylindrical shaped body defining an arm member perforation 550 therethrough. The arm member perforation 550 has a diameter which permits the arm member 110 ″″ to be disposed therethrough. The at least one arm member fastener 548 is threadingly disposed in a perforation that intersects the arm member perforation 550 . When the at least one arm member fastener 548 is driven to engage the arm member 110 ″″ disposed in the arm member perforation 550 , the arm member 110 ″″ is coupled to the main body 540 .
The central portion 544 is an elongate member having a rectangular cross section. The central portion 544 is oriented transversely to an axis of the fastening portion 542 . The cone pin 546 extends from a distal end of the central portion 544 .
The cone pin 546 is integrally formed with the central portion 544 , has a substantially circular cross-section and extends outwardly from the central portion 544 and is substantially parallel to the axis of the fastening portion 542 . Alternately, the cone pin 546 may be coupled to the central portion 544 in any conventional manner. A diameter of the cone pin 546 substantially corresponds to the apertures 102 of the first end cone 19 .
In use, the spring winding device 10 and the anti-rotation device 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ are used to adjust an amount of counterbalancing force in one or more torsion springs 17 forming a portion of the torsion spring counterbalancing mechanism. FIG. 11 illustrates the anti-rotation device 100 ″″ being used to adjust an amount of counterbalancing force in one or more torsion springs 17 .
First, one of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ is coupled to each of the first end cones 19 . The cone pins 112 , 118 , the cone pins 112 ′, 118 ′, the cone pins 346 of each of the main bodies 340 , the cone pin 470 and the second end of the shaft portion 468 , or the cone pins 546 of each of the main bodies 540 are respectively disposed in the apertures 102 of each of the first end cones 19 to drivingly engage the first end cone 19 with one of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″. By adjusting one of the first cone pin 112 , 112 ′, each of the arm member fasteners 348 , the adjuster fastener 462 and the shaft portion 468 , or each of the arm member fasteners 548 , each of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ may be coupled and drivingly engaged with one of the first end cones 19 . Further, it is understood that a length of the arm member 110 , 210 , 110 ″, 410 , 110 ″″ may be adjusted based on an amount of counterbalancing force stored in the torsion springs 17 or an amount of counterbalancing force to be stored in the torsion springs 17 .
Next, the fastener 49 coupling the flanged worm gear 14 to the support bracket 12 is removed. The fastener 49 is removed from one of the set perforations 48 of the gear portion 38 and the flanged worm gear fastening perforation 29 of the main portion 26 . Preferably, the fastener 49 is disposed through the flanged worm gear fastening perforation 29 and engaged with a thread formed in one of the set perforations 48 ; however, it is understood that other fasteners, such as a nut and a bolt, may be used.
Next, the at least one set screw 21 of each of the first end cones 19 are adjusted to disengage the first end cone 19 from the torsion shaft 18 . When the first end cones 19 are disengaged from the torsion shaft 18 , the amount of counterbalancing force stored in the torsion springs 17 is applied to the anti-rotation device 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ engaged with each of the first end cones 19 . As a result, the bumper portion 132 , 132 ′, 132 ″, 132 ′″, 132 ″″ of each of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ contacts the wall 24 or the overhead door to resist the amount of counterbalancing force stored in the torsion springs 17 .
Next, the amount of counterbalancing force stored in the torsion springs 17 is adjusted using the spring winding device 10 . The amount of counterbalancing force stored in the torsion springs 17 may be increased or decreased by rotating the drive gear 60 . When the driving tool engaged with the drive end 72 of the drive gear 60 is rotated, the drive gear 60 rotates and the at least one thread 68 applies a force to the toothed outer edge 46 of the flanged worm gear 14 , causing the flanged worm gear 14 to rotate within the support bracket 12 . The second end cones 20 , which are coupled to the flanged worm gear 14 , rotate in response to rotation of the drive gear 60 and the amount of counterbalancing force stored in the torsion springs 17 is adjusted simultaneously. As shown in FIGS. 1-3 and 11 , the spring winding device 10 is used to adjust the amount of counterbalancing force stored in two torsion springs 17 . Depending on a direction the drive gear 60 is rotated, the amount of counterbalancing force stored in the torsion springs 17 may be increased or decreased. It is understood that at least one of the flanged worm gear 14 and the support bracket 12 may be fitted with a device (not shown) for counting a number of rotations made by the flanged worm gear 14 during the process used to adjust the amount of counterbalancing force stored in the torsion springs 17 . Such a device facilitates properly adjusting the amount of counterbalancing force stored in the torsion springs 17 .
The anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ are able to move with respect to the torsion shaft 18 as the amount of counterbalancing force stored in each of the torsion springs 17 coupled thereto is adjusted. It is understood that when the amount of counterbalancing force stored in each of the torsion springs 17 is adjusted, a length of each of the torsion springs 17 changes. In response to the length of each of the torsion springs 17 changing, the bumper portion 132 , 132 ′, 132 ″, 132 ′″, 132 ″″ of each of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ rotates about the arm member 110 , 210 , 110 ″, 410 , 110 ″″ against the wall 24 and the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ and the first end cones 19 move along the torsion shaft 18 . The anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ militate against a binding that may occur to the torsion springs 17 if the amount of counterbalancing force stored in each of the torsion springs 17 is adjusted without allowing the length of each of the torsion springs 17 to change.
Once a desired amount of counterbalancing force stored in the torsion springs is obtained, the flanged worm gear 14 is coupled to the support bracket 12 . The fastener 49 is disposed through the flanged worm gear fastening perforation 29 of the main portion 26 and into one of the set perforations 48 of the gear portion 38 and the fastener 49 is tightened to militate against relative movement from occurring between the flanged worm gear 14 and the support bracket 12 .
Next, the at least one set screw 21 of each of the first end cones 19 are adjusted to engage each of the first end cones 19 with the torsion shaft 18 , allowing the amount of counterbalancing force stored in the torsion springs 17 to be applied to the torsion shaft.
Lastly, each of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ coupled to the first end cones 19 is removed. By reversing the above procedure used to couple the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ to the first end cones 19 , the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ are removed from the first end cones 19 , and the process used to adjust the amount of counterbalancing force in one or more torsion springs 17 is completed.
Further, it is understood that the spring winding device 10 and a pair of the keyed end cones 19 ′ may also be used to adjust an amount of counterbalancing force in one or more torsion springs 17 forming a portion of the torsion spring counterbalancing mechanism. In use, the spring winding device 10 and the keyed end cones 19 ′ are used to adjust an amount of counterbalancing force in one or more torsion springs 17 forming a portion of the torsion spring counterbalancing mechanism, without the use of one of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″.
First, the at least one set screw 21 of each of the keyed end cones 19 ′ are adjusted to disengage the keyed end cones 19 ′ from the torsion shaft 18 . When the keyed end cones 19 ′ are disengaged from the torsion shaft 18 , each of the keyed end cones 19 ′ is able to be moved along a length of the torsion shaft 18 while maintaining driving engagement with the torsion shaft 18 .
Next, the amount of counterbalancing force stored in the torsion springs 17 is adjusted using the spring winding device 10 . The amount of counterbalancing force stored in the torsion springs 17 may be increased or decreased by rotating the drive gear 60 . When the driving tool engaged with the drive end 72 of the drive gear 60 is rotated, the drive gear 60 rotates and the at least one thread 68 applies a force to the toothed outer edge 46 of the flanged worm gear 14 , causing the flanged worm gear 14 to rotate within the support bracket 12 . The second end cones 20 , which are coupled to the flanged worm gear 14 , rotate in response to rotation of the drive gear 60 and the amount of counterbalancing force stored in the torsion springs 17 is adjusted simultaneously.
In response to the amount of counterbalancing force stored in the torsion springs 17 being adjusted, each of the keyed end cones 19 ′ move along the torsion shaft 18 as a length of each of the torsion springs 17 coupled thereto is adjusted. The key 23 of each of the keyed end cones 19 ′ move along keyway 22 of the torsion shaft 18 in response to an axial force generated by the amount of counterbalancing force stored in the torsion springs 17 being adjusted. When the amount of counterbalancing force stored in the torsion springs 17 is increased, the length of each of the torsion springs 17 decreases, and each of the keyed end cones 19 ′ move along the torsion shaft 18 towards the spring winding device 10 . When the amount of counterbalancing force stored in the torsion springs 17 is decreased, the length of each of the torsion springs 17 increases, and each of the keyed end cones 19 ′ move along the torsion shaft 18 away from the spring winding device 10 .
Once a desired amount of counterbalancing force stored in the torsion springs is obtained, the flanged worm gear 14 is coupled to the support bracket 12 . The fastener 49 is disposed through the flanged worm gear fastening perforation 29 of the main portion 26 and into one of the set perforations 48 of the gear portion 38 and the fastener 49 is tightened to militate against relative movement from occurring between the flanged worm gear 14 and the support bracket 12 .
Lastly, the at least one set screw 21 of each of the keyed end cones 19 ′ are adjusted to fix each of the keyed end cones 19 ′ with respect to the torsion shaft 18 . When the keyed end cones 19 ′ are fixed to the torsion shaft 18 , each of the keyed end cones 19 ′ is unable to be moved along a length of the torsion shaft 18 .
The keyed end cone 19 ′ having the key 23 formed thereon eliminates a need for one of the anti-rotation devices 100 , 100 ′, 100 ″, 100 ′″, 100 ″″ when an amount of counterbalancing force stored in each of the torsion springs 17 is adjusted.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A spring winding device, a counterbalancing force adjustment device for a counterbalancing mechanism, and a method of adjusting an amount of force stored in a spring of a counterbalancing mechanism are provided. The spring winding device includes a support bracket, a worm gear, and a drive gear. The worm gear is rotatably coupled to the support bracket and includes a mount portion for coupling a first end cone thereto. The drive gear is rotatably disposed adjacent the support bracket and is drivingly engaged with the worm gear. A rotation of the drive gear causes the worm gear to rotate within the support bracket. The spring winding device does not require pretensioning using winding rods, maintains rigidity and alignment when a counterbalancing force is applied, and decreases a cost and a complexity of the counterbalancing mechanism. | 4 |
This application is a continuation-in-part application of U.S. application Ser. No. 13/708,035 filed on Dec. 7, 2012, from which priority is claimed. U.S. application Ser. No. 13/708,035 is a continuation of U.S. application Ser. No. 12/942,238, filed on Nov. 9, 2010 (now issued as U.S. Pat. No. 8,415,657 on Apr. 9, 2013). Furthermore, U.S. application Ser. No. 12/942,238 is a continuation-in-part application of U.S. application Ser. No. 12/708,872, filed on Feb. 19, 2010 (now issued as U.S. Pat. No. 8,318,572 on Nov. 27, 2012).
This document relates to the subject matter of a joint research agreement between Intermolecular, Inc. and Elpida Memory, Inc.
FIELD OF THE INVENTION
The present invention generally relates to the field of dynamic random access memory (DRAM), and more particularly to dielectric material processing for improved DRAM performance.
BACKGROUND OF THE INVENTION
Dynamic Random Access Memory utilizes capacitors to store bits of information within an integrated circuit. A capacitor is formed by placing a dielectric material between two electrodes formed from conductive materials. A capacitor's ability to hold electrical charge (i.e., capacitance) is a function of the surface area of the capacitor plates A, the distance between the capacitor plates d (i.e. the physical thickness of the dielectric layer), and the relative dielectric constant or k-value of the dielectric material. The capacitance is given by:
C = κ ɛ o A d ( Eqn . 1 )
where ∈ o represents the vacuum permittivity.
The dielectric constant is a measure of a material's polarizability. Therefore, the higher the dielectric constant of a material, the more charge the capacitor can hold. Therefore, if the k-value of the dielectric is increased, the area of the capacitor can be decreased and maintain the desired cell capacitance. Reducing the size of capacitors within the device is important for the miniaturization of integrated circuits. This allows the packing of millions (mega-bit (Mb)) or billions (giga-bit (Gb)) of memory cells into a single semiconductor device. The goal is to maintain a large cell capacitance (generally ˜10 to 25 fF) and a low leakage current (generally <10 −7 A cm −2 ). The physical thickness of the dielectric layers in DRAM capacitors could not be reduced unlimitedly in order to avoid leakage current caused by tunneling mechanisms which exponentially increases as the thickness of the dielectric layer decreases.
Traditionally, SiO 2 has been used as the dielectric material and semiconducting materials (semiconductor-insulator-semiconductor [SIS] cell designs) have been used as the electrodes. The cell capacitance was maintained by increasing the area of the capacitor using very complex capacitor morphologies while also decreasing the thickness of the SiO 2 dielectric layer. Increases of the leakage current above the desired specifications have demanded the development of new capacitor geometries, new electrode materials, and new dielectric materials. Cell designs have migrated to metal-insulator-semiconductor (MIS) and now to metal-insulator-metal (MIM) cell designs for higher performance.
One class of high k dielectric materials possessing the characteristics required for implementation in advanced DRAM capacitors are high k metal oxide materials. Examples of suitable dielectric materials comprise SiO 2 , a bilayer of SiO 2 and Si x N y , SiON, Al 2 O 3 , HfO 2 , HfSiO x , ZrO 2 , Ta 2 O 5 , TiO 2 , Nb 2 O 5 , SrTiO 3 (STO), BaSrTiO x (BST), PbZrTiO x (PZT), etc. TiO 2 and ZrO 2 are two specific examples of metal oxide dielectric materials which display significant promise in terms of serving as a high k dielectric material for implementation in DRAM capacitors.
Typically, DRAM devices at technology nodes of 80 nm and below use MIM capacitors wherein the electrode materials are metals. These electrode materials generally have higher conductivities than the semiconductor electrode materials, higher work functions, exhibit improved stability over the semiconductor electrode materials, and exhibit reduced depletion effects. The electrode materials must have high conductivity to ensure fast device speeds. Representative examples of electrode materials for MIM capacitors are metals, conductive metal oxides, conductive metal silicides, conductive metal nitrides (i.e. TiN), or combinations thereof. MIM capacitors in these DRAM applications utilize insulating materials having a dielectric constant, or k-value, significantly higher than that of SiO 2 (k=3.9). For DRAM capacitors, the goal is to utilize dielectric materials with k values greater than about 40. Such materials are generally classified as high k materials. Representative examples of high k materials for MIM capacitors are non-conducting metal oxides, non-conducting metal nitrides, non-conducting metal silicates or combinations thereof. These dielectrics may also include additional dopant materials.
A figure of merit in DRAM technology is the electrical performance of the dielectric material as compared to SiO 2 known as the Equivalent Oxide Thickness (EOT). A high k material's EOT is calculated using a normalized measure of silicon dioxide (SiO 2 k=3.9) as a reference, given by:
EOT = 3.9 κ · d ( Eqn . 2 )
where d represents the physical thickness of the capacitor dielectric.
As DRAM technologies scale below the 40 nm technology node, manufacturers must reduce the EOT of the high k dielectric films in MIM capacitors in order to increase charge storage capacity. The goal is to utilize dielectric materials that exhibit an EOT of less than about 0.8 nm while maintaining a physical thickness of about 5-20 nm.
Generally, as the dielectric constant of a material increases, the band gap of the material decreases. For example. The rutile phase of TiO 2 has a k-value of about 80 and a band gap of about 3.0 eV while ZrO 2 in the tetragonal phase has a k-value of about 43 and a band gap of about 5.8 eV. The low band gap may lead to high leakage current in the device. As a result, without the utilization of countervailing measures, capacitor stacks implementing high k dielectric materials may experience large leakage currents. High work function electrodes (e.g., electrodes having a work function of greater than 5.0 eV) may be utilized in order to counter the effects of implementing a reduced band gap high k dielectric layer within the DRAM capacitor. Metals, such as platinum, gold, ruthenium, and ruthenium oxide are examples of high work function electrode materials suitable for inhibiting device leakage in a DRAM capacitor having a high k dielectric layer. The noble metal systems, however, are prohibitively expensive when employed in a mass production context. Moreover, electrodes fabricated from noble metals often suffer from poor manufacturing qualities, such as surface roughness, poor adhesion, and form a contamination risk in the fab.
Conductive metal oxides, conductive metal silicides, conductive metal nitrides, or combinations thereof comprise other classes of materials that may be suitable as DRAM capacitor electrodes. Generally, transition metals and their conductive binary compounds form good candidates as electrode materials. The transition metals exist in several oxidation states. Therefore, a wide variety of compounds are possible. Different compounds may have different crystal structures, electrical properties, etc. It is important to utilize the proper compound for the desired application.
In one example, molybdenum has several binary oxides of which MoO 2 and MoO 3 are two examples. These two oxides of molybdenum have different properties. MoO 2 has shown great promise as an electrode material in DRAM capacitors. MoO 2 has a distorted rutile crystal structure and serves as an acceptable template to promote the deposition of the rutile-phase of TiO 2 as discussed above. MoO 2 also has a high work function (can be >5.0 eV depending on process history) which helps to minimize the leakage current of the DRAM device. However, oxygen-rich phases (MoO 2+x ) degrade the performance of the MoO 2 electrode because they do not promote the deposition of the rutile-phase of TiO 2 and have higher resistivity than MoO 2 . For example, MoO 3 (the most oxygen-rich phase) has an orthorhombic crystal structure and is a dielectric.
Generally, a deposited thin film may be amorphous, crystalline, or a mixture thereof. Furthermore, several different crystalline phases may exist. Therefore, processes (both deposition and post-treatment) must be developed to maximize the formation of crystalline MoO 2 and to minimize the presence of MoO 2+x phases. Deposition processes and post-treatment processes in a reducing atmosphere have been developed that allow crystalline MoO 2 to be used as the first electrode (i.e. bottom electrode) in DRAM MIM capacitors with TiO 2 or doped-TiO 2 high k dielectric materials. Examples of the post-treatment process are further described in U.S. application Ser. No. 13/084,666 filed on Apr. 12, 2011, entitled “METHOD FOR FABRICATING A DRAM CAPACITOR” which is incorporated herein by reference. However, these DRAM MIM capacitors have continued to use noble metal (i.e. Ru) materials for the second electrode (i.e. top electrode).
After the formation of the second electrode, the capacitor stack is then subjected to a post metallization anneal (PMA) treatment. The PMA treatment serves to crystallize the second electrode and to anneal defects in the dielectric and interface states that are formed at the dielectric/second electrode interface during the deposition. Also, if there is no post dielectric anneal (PDA) treatment done before metallization, the PMA treatment can serve to crystallize the dielectric layer to improve the k value and fill oxygen vacancies. Examples of the PDA and PMA treatments are further described in U.S. application Ser. No. 13/159,842 filed on Jun. 14, 2011, entitled “METHOD OF PROCESSING MIM CAPACITORS TO REDUCE LEAKAGE CURRENT” and is incorporated herein by reference. As discussed above, MoO 2 is sensitive to oxidation to form oxygen-rich compounds that negatively impacts its performance as an electrode material. The reducing atmosphere anneal processes discussed previously with respect to the use of crystalline MoO 2 as a first electrode are not an option at this stage of the device manufacture because they would degrade the performance of the dielectric layer through the formation of oxygen vacancies. TiO 2 high k dielectric materials are especially sensitive to processing conditions and increases in the leakage current are observed, likely due to the formation of oxygen vacancies.
At some DRAM device nodes, TiN may be used as the first electrode. TiN may be used with ZrO 2 dielectric layers because the high k tetragonal phase of ZrO 2 forms easily on TiN. The oxygen moiety within the ZrO 2 layer is reasonably stable and the concentration of oxygen vacancies is low. This contributes to the low leakage current observed for ZrO 2 dielectric layers. However, since the k-value is lower than desired (k<˜43), the EOT is too large for next generation DRAM technologies. As an example, ZrO 2 MIM capacitors can have leakage currents in the range of about 8×10 −8 A/cm 2 at an EOT of about 0.70 nm to about 1.5×10 −8 A/cm 2 at an EOT of about 0.85 nm. The EOT target for next generation DRAM technologies is less than about 0.60 nm. In the case of ZrO 2 dielectric layers, TiN is typically used as the second electrode as well.
As discussed previously, the rutile phase of TiO 2 is an attractive candidate high k dielectric material with a k-value in excess of about 80 depending on processing conditions. The high k-value should allow the formation of MIM capacitor stacks with low EOT values within the physical thickness constraints of advanced DRAM technologies. The use of crystalline MoO 2 would be attractive as a first electrode since it would serve as a good template to promote the formation of the rutile phase of TiO 2 . Ideally, the crystalline MoO 2 would be used as the second electrode as well to form a symmetric MIM stack. However, currently Ru is used for the second electrode due to integration issues surrounding the use of MoO 2 as the second electrode. As discussed previously, both MoO 2 and TiO 2 are very sensitive to the environment used during the various annealing steps. The oxidation of MoO 2 to MoO 2+x and the loss of oxygen in TiO 2 to form oxygen vacancies both contribute to the higher leakage current observed in MIM stacks using these materials. As an example, TiO 2 MIM capacitors can have leakage currents in the range of about 8×10 −6 A/cm 2 at an EOT of about 0.38 nm to about 1.0×10 −7 A/cm 2 at an EOT of about 0.50 nm.
Therefore, there is a need to develop methods for forming capacitor stacks that combine the low leakage current and simple integration processes of ZrO 2 based dielectric layers with the high k and low EOT benefits of TiO 2 based dielectric layers.
SUMMARY OF THE DISCLOSURE
In some embodiments of the present invention, a crystalline MoO 2 first electrode is used to promote the formation of the rutile phase of a TiO 2 dielectric layer that is subsequently formed. The MoO 2 first electrode may be annealed to increase the crystallinity and to reduce unwanted MoO 2+x phases that may be present. The TiO 2 dielectric layer may be doped to reduce the leakage current. The TiO 2 dielectric layer may be annealed to increase the crystallinity and to reduce the concentration of oxygen vacancies that may be present. An amorphous ZrO 2 dielectric layer is formed on top of the TiO 2 dielectric layer. The amorphous ZrO 2 dielectric layer reduces the leakage current of the capacitor stack. A TiN second electrode is formed on top of the amorphous ZrO 2 dielectric layer. The TiN second electrode is compatible with the amorphous ZrO 2 dielectric layer and is easy to integrate into current DRAM manufacturing process flows.
BRIEF DESCRIPTION OF THE DRAWINGS
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The drawings are not to scale and the relative dimensions of various elements in the drawings are depicted schematically and not necessarily to scale.
The techniques of the present invention can readily be understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a flow chart illustrating a method for fabricating a DRAM capacitor stack in accordance with some embodiments of the present invention.
FIG. 2 illustrates a simplified cross-sectional view of a DRAM capacitor stack fabricated in accordance with some embodiments of the present invention.
FIG. 3 illustrates a simplified cross-sectional view of a DRAM capacitor stack fabricated in accordance with some embodiments of the present invention.
FIG. 4 illustrates a simplified cross-sectional view of a DRAM capacitor stack fabricated in accordance with some embodiments of the present invention.
FIG. 5 presents data for leakage current at 1V versus EOT.
FIG. 6 presents data for leakage current at 1V versus Physical Thickness.
FIG. 7 illustrates a simplified cross-sectional view of a DRAM memory cell fabricated in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION
A detailed description of one or more embodiments is provided below along with accompanying figures. The detailed description is provided in connection with such embodiments, but is not limited to any particular example. The scope is limited only by the claims and numerous alternatives, modifications, and equivalents are encompassed. Numerous specific details are set forth in the following description in order to provide a thorough understanding. These details are provided for the purpose of example and the described techniques may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description.
FIG. 1 describes a method, 100 , for fabricating a DRAM capacitor stack. The initial step, 102 , comprises forming a first electrode layer on a substrate. Examples of suitable electrode materials comprise metals, metal alloys, conductive metal oxides, conductive metal silicides, conductive metal nitrides, or combinations thereof. A particularly interesting class of materials is the conductive metal oxides. Optionally, the first electrode layer can then be subjected to an annealing process (not shown). The next step, 104 , comprises forming a crystalline, doped first dielectric material on the first electrode layer. Optionally, the first dielectric layer can then be subjected to an annealing process (not shown). The next step, 106 , comprises forming an amorphous, doped second dielectric layer on the first dielectric layer. The next step, 108 , comprises forming a second electrode on the second dielectric layer.
Those skilled in the art will appreciate that each of the first electrode layer, the first and second dielectric layers, and the second electrode used in the DRAM MIM capacitor may be formed using any common formation technique such as atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PE-ALD), atomic vapor deposition (AVD), ultraviolet assisted atomic layer deposition (UV-ALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), or physical vapor deposition (PVD). Generally, because of the complex morphology of the DRAM capacitor structure, ALD, PE-ALD, AVD, or CVD are preferred methods of formation. However, any of these techniques are suitable for forming each of the various layers discussed below. Those skilled in the art will appreciate that the teachings described below are not limited by the technology used for the deposition process.
In FIGS. 2-5 below, a capacitor stack is illustrated using a simple planar structure. Those skilled in the art will appreciate that the description and teachings to follow can be readily applied to any simple or complex capacitor morphology. The drawings are for illustrative purposes only and do not limit the application of the present invention.
FIG. 2 illustrates a simple capacitor stack, 200 , consistent with a DRAM MIM capacitor stack comprising crystalline metal oxide electrode layers and a doped high k dielectric layer. First electrode layer, 202 , is formed on substrate, 201 . Generally, the substrate has already received several processing steps in the manufacture of a full DRAM device. First electrode layer, 202 , comprises one of metals, metal alloys, conductive metal oxides, conductive metal nitrides, conductive metal silicides, or combinations thereof, etc. For this example, first electrode layer, 202 , comprises a conductive metal oxide that may serve to promote the rutile phase of TiO 2 . Examples of such conductive metal oxides include the conductive compounds of molybdenum oxide, tungsten oxide, ruthenium oxide, iron oxide, iridium oxide, chromium oxide, manganese oxide, tin oxide, cobalt oxide, or nickel oxide. A specific electrode material of interest is the crystalline MoO 2 compound of molybdenum dioxide.
Optionally, first electrode, 202 , can be annealed to crystallize the material. In the case of crystalline MoO 2 , it is advantageous to anneal the first electrode in a reducing atmosphere such as Ar, N 2 , or forming gas to prevent the formation of oxygen-rich compounds. Examples of such an annealing process is further described in U.S. application Ser. No. 13/084,666 filed on Apr. 12, 2011, entitled “METHOD FOR FABRICATING A DRAM CAPACITOR” and is incorporated herein by reference.
In one example of a DRAM MIM capacitor stack comprising crystalline metal oxide electrode layers and a doped high k dielectric layer, a first electrode comprising between about 5 nm and about 10 nm of molybdenum oxide is formed on a substrate. The molybdenum oxide electrode material is formed at a process temperature between about 125 C and 400 C using an ALD process technology. Optionally, the substrate with the first electrode is then annealed in a reducing atmosphere comprising between about 1% and about 20% H 2 in N 2 and advantageously between about 5% and about 10% H 2 in N 2 between 400 and 520 C for between about 1 millisecond and about 60 minutes as discussed previously.
In the next step, dielectric layer, 204 , would then be formed on the annealed first electrode layer, 202 . A wide variety of dielectric materials have been targeted for use in DRAM capacitors. Examples of suitable dielectric materials comprise SiO 2 , a bilayer of SiO 2 and Si x N y , SiON, Al 2 O 3 , HfO 2 , HfSiO x , ZrO 2 , Ta 2 O 5 , TiO 2 , Nb 2 O 5 , SrTiO 3 (STO), BaSrTiO x (BST), PbZrTiO x (PZT), or doped versions of the same. These dielectric materials may be formed as a single layer or may be formed as a hybrid or nanolaminate structure. Typically, dielectric layer, 204 , is subjected to a PDA treatment before the formation of the second electrode as discussed previously. A specific dielectric material of interest is TiO 2 doped with one of Al, Zr, Ge, Hf, Sn, Sr, Y, Si, La, Er, Ga, Gd, Mg, Co, or combinations thereof. A specific dielectric material of interest is TiO 2 doped with Al 2 O 3 to between about 5 atomic % and about 15 atomic % Al.
In a specific example, the dielectric layer comprises between about 6 nm to about 10 nm of TiO 2 wherein at least 30% of the TiO 2 is present in the rutile phase. Generally, the TiO 2 dielectric layer may either be a single film or may comprise a nanolaminate. Advantageously, the TiO 2 material is doped with Al at a concentration between about 5 atomic % and about 15 atomic % Al. The TiO 2 dielectric layer is formed at a process temperature between about 200 C and 350 C using an ALD process technology. The substrate with the first electrode and dielectric layer is then annealed in an oxidizing atmosphere comprising between about 0% O 2 to about 100% O 2 in N 2 and advantageously between about 0% O 2 to about 20% O 2 in N 2 at temperatures between about 400 C to about 600 C for between about 1 millisecond to about 60 minutes.
In the next step, the second electrode, 206 , is formed on dielectric layer, 204 . The second electrode may be a one of, metals, metal alloys, conductive metal oxides, conductive metal nitrides, conductive metal silicides, or combinations thereof, etc. In this example, the second electrode is a conductive metal oxide, and more specifically, crystalline MoO 2 .
In one example of the present invention, the second electrode comprising between about 0.1 nm and about 100 nm of molybdenum oxide is formed on the TiO 2 dielectric layer. The crystalline MoO 2 electrode material is formed at a process temperature between about 125 C and 400 C using an ALD process technology. The capacitor stack, 200 , is then subjected to a PMA treatment as discussed earlier. However, as mentioned previously, DRAM MIM capacitors with this configuration exhibit high leakage current.
FIG. 3 illustrates a simplified cross-sectional view of a DRAM capacitor stack fabricated in accordance with some embodiments of the present invention. This example will use ZrO 2 as the dielectric material. However, those skilled in the art will understand that the present methods may be applied to many dielectric materials. First electrode, 302 , is formed on substrate, 201 . When ZrO 2 is used as the dielectric material, the first electrode is advantageously TiN. The TiN first electrode may optionally receive a treatment before the formation of the multi-layer dielectric material. If the first electrode layer is TiN or another conductive metal nitride material, then the first electrode layer may be annealed using a Rapid Thermal Anneal (RTA) technique or furnace anneal technique. For the RTA case, the temperature is quickly raised in the presence of a nitrogen containing gas such as N 2 , forming gas, NH 3 , etc. Examples of such electrode treatment steps are further described in U.S. application Ser. No. 13/051,531 filed on Mar. 18, 2011, which is incorporated herein by reference. A doped ZrO 2 layer, 304 , is then formed on top of the TiN first electrode. Suitable dopants for use with ZrO 2 dielectric materials comprise Al, Ge, Hf, Sn, Sr, Y, Si, Ti, La, Er, Ga, Gd, Mg, Co, or combinations thereof. The dopant concentration is selected such that the ZrO 2 layer remains amorphous after subsequent annealing treatments. The dielectric layer may receive a PDA treatment as discussed previously. Second electrode layer, 306 , is then formed on top of the multi-layer dielectric material. Examples of suitable materials for the second electrode layer comprise Ru, TiN, Pt, Ir, Pd, Ni, Co, NiN, WN, VN, NiO, RuO 2 , CoN, MoN, or combinations thereof. When ZrO 2 is used as the dielectric material, the second electrode is advantageously TiN. The capacitor stack may receive a PMA treatment as discussed previously. DRAM MIM capacitors with this configuration will exhibit low leakage current but will also exhibit high EOT values due to the relatively low k value of ZrO 2 .
FIG. 4 illustrates a simple capacitor stack, 400 , consistent with a DRAM MIM capacitor stack according to some embodiments of the present invention comprising a crystalline metal oxide first electrode layer, a crystalline, doped high k first dielectric layer, an amorphous, doped high k second dielectric layer, and a metal nitride second electrode layer. First electrode layer, 402 , is formed on substrate, 401 . Generally, the substrate has already received several processing steps in the manufacture of a full DRAM device. First electrode layer, 402 , comprises one of metals, metal alloys, conductive metal oxides, conductive metal nitrides, conductive metal silicides, or combinations thereof, etc. For this example, first electrode layer, 402 , comprises a conductive metal oxide that may serve to promote the rutile phase of TiO 2 . Examples of such conductive metal oxides include the conductive compounds of molybdenum oxide, tungsten oxide, ruthenium oxide, iron oxide, iridium oxide, chromium oxide, manganese oxide, tin oxide, cobalt oxide, or nickel oxide. A specific electrode material of interest is the crystalline MoO 2 compound of molybdenum dioxide. Optionally, first electrode, 402 , can be annealed to crystallize the material as discussed previously.
In the next step, crystalline, doped first dielectric layer, 404 , would then be formed on the annealed first electrode layer, 402 . A wide variety of dielectric materials have been targeted for use in DRAM capacitors. Examples of suitable dielectric materials comprise SiO 2 , a bilayer of SiO 2 and Si x N y , SiON, Al 2 O 3 , HfO 2 , HfSiO x , ZrO 2 , Ta 2 O 5 , TiO 2 , Nb 2 O 5 , SrTiO 3 (STO), BaSrTiO x (BST), PbZrTiO x (PZT), or doped versions of the same. These dielectric materials may be formed as a single layer or may be formed as a hybrid or nanolaminate structure. A specific dielectric material of interest is TiO 2 doped with one of Al, Zr, Ge, Hf, Sn, Sr, Y, Si, La, Er, Ga, Gd, Mg, Co, or combinations thereof. A specific dielectric material of interest is TiO 2 doped with Al 2 O 3 to between about 5 atomic % and about 15 atomic % Al.
In a specific example, the crystalline, doped first dielectric layer comprises between about 6 nm to about 10 nm of TiO 2 wherein at least 30% of the TiO 2 is present in the rutile phase. Generally, the TiO 2 first dielectric layer may either be a single film or may comprise a nanolaminate. Advantageously, the TiO 2 material is doped with Al at a concentration between about 5 atomic % and about 15 atomic % Al. The TiO 2 first dielectric layer is formed at a process temperature between about 200 C and 350 C using an ALD process technology.
In the next step, amorphous, doped second dielectric layer, 406 , would then be formed on the crystalline, doped first dielectric layer, 404 . A wide variety of dielectric materials have been targeted for use in DRAM capacitors. Examples of suitable dielectric materials comprise SiO 2 , a bilayer of SiO 2 and Si x N y , SiON, Al 2 O 3 , HfO 2 , HfSiO x , ZrO 2 , Ta 2 O 5 , TiO 2 , Nb 2 O 5 , SrTiO 3 (STO), BaSrTiO x (BST), PbZrTiO x (PZT), or doped versions of the same. These dielectric materials may be formed as a single layer or may be formed as a hybrid or nanolaminate structure. Suitable dopants for use with ZrO 2 dielectric materials comprise Al, Ge, Hf, Sn, Sr, Y, Si, Ti, La, Er, Ga, Gd, Mg, Co, or combinations thereof. The dopant concentration is selected such that the ZrO 2 layer remains amorphous after subsequent annealing treatments. A specific dielectric material of interest is ZrO 2 doped with Al 2 O 3 . The ZrO 2 layer needs to be thick enough that it forms a continuous layer. Therefore, the minimum thickness is about 0.5 nm. Additionally, the ZrO 2 layer should be thin enough that it remains amorphous after subsequent annealing treatments. Therefore, the maximum thickness is about 2.0 nm. Advantageously, the thickness of the ZrO 2 layer is in the range from about 0.7 nm to about 1.5 nm. The thickness of the ZrO 2 layer is typically less than or equal to 25% of the total dielectric thickness of the DRAM MIM capacitor (i.e. the total thickness of the combination of the crystalline, doped high k first dielectric layer and the amorphous, doped high k second dielectric layer).
The substrate with the first electrode, a crystalline, doped high k first dielectric layer, and an amorphous, doped high k second dielectric layer is then annealed in an oxidizing atmosphere comprising between about 0% O 2 to about 100% O 2 in N 2 and advantageously between about 0% O 2 to about 20% O 2 in N 2 at temperatures between about 400 C to about 600 C for between about 1 millisecond to about 60 minutes.
Second electrode is then formed on top of the multi-layer dielectric material. Examples of suitable materials for the second electrode layer comprise Ru, TiN, Pt, Ir, Pd, Ni, Co, NiN, WN, VN, NiO, RuO 2 , CoN, MoN, or combinations thereof. When ZrO 2 is used as the dielectric material, the second electrode is advantageously TiN. The capacitor stack may receive a PMA treatment as discussed previously.
DRAM MIM capacitors with the configuration illustrated in FIG. 4 will exhibit low leakage current due to the current blocking properties of the amorphous, doped high k second dielectric layer. Additionally, the DRAM MIM capacitor will exhibit low EOT values due to the high k value of the crystalline, doped high k first dielectric layer. A further benefit of the DRAM MIM capacitor stack illustrated in FIG. 4 is that it is easy to integrate into existing DRAM manufacturing process flows. The use, treatment, materials compatibility, reliability, etc. of TiN second electrodes are well established. Therefore, the DRAM MIM capacitor stack illustrated in FIG. 4 represents an opportunity to integrate the benefits of the MoO 2 first electrode and the high k properties of doped TiO 2 into the DRAM MIM manufacturing process without having to adapt to the use of new material as a second electrode.
The benefits of some embodiments of the present invention are illustrated in the data presented in FIG. 5 . A first group of simple capacitor stacks were formed comprising a MoO 2 first electrode, an Al-doped TiO 2 dielectric layer, and a Pt second electrode. These samples are denoted TA-A Pt TEC in the legend and illustrated by the black circles in FIG. 5 . A second group of simple capacitor stacks were formed comprising a MoO 2 first electrode, an Al-doped TiO 2 first dielectric layer, a doped amorphous ZrO 2 second dielectric layer, and a Pt second electrode. These samples are denoted TA-Z Pt TEC in the legend and illustrated by the gray triangles in FIG. 5 . As illustrated in FIG. 5 , The TA-Z Pt TEC samples exhibited lower leakage current than the TA-A Pt TEC samples at a given EOT thickness. Additionally, the TA-Z Pt TEC samples exhibited a lower EOT for an equivalent level of leakage current.
The benefits of some embodiments of the present invention are illustrated in the data presented in FIG. 6 . A first group of simple capacitor stacks were formed comprising a MoO 2 first electrode, an Al-doped TiO 2 dielectric layer, and a Pt second electrode. These samples are denoted TA-A Pt TEC in the legend and illustrated by the black circles in FIG. 6 . A second group of simple capacitor stacks were formed comprising a MoO 2 first electrode, an Al-doped TiO 2 first dielectric layer, a doped amorphous ZrO 2 second dielectric layer, and a Pt second electrode. These samples are denoted TA-Z Pt TEC in the legend and illustrated by the gray triangles in FIG. 6 . As illustrated in FIG. 6 , The TA-Z Pt TEC samples exhibited lower leakage current than the TA-A Pt TEC samples at a given physical thickness.
An example of a specific application of some embodiments of the present invention is in the fabrication of capacitors used in the memory cells in DRAM devices. DRAM memory cells effectively use a capacitor to store charge for a period of time, with the charge being electronically “read” to determine whether a logical “one” or “zero” has been stored in the associated cell. Conventionally, a cell transistor is used to access the cell. The cell transistor is turned “on” in order to store data on each associated capacitor and is otherwise turned “off” to isolate the capacitor and preserve its charge. More complex DRAM cell structures exist, but this basic DRAM structure will be used for illustrating the application of this disclosure to capacitor manufacturing and to DRAM manufacturing. FIG. 7 is used to illustrate one DRAM cell, 720 , manufactured using a bilayer dielectric structure as discussed previously. The cell, 720 , is illustrated schematically to include two principle components, a cell capacitor, 700 , and a cell transistor, 702 . The cell transistor is usually constituted by a MOS transistor having a gate, 716 , source, 712 , and drain, 714 . The gate is usually connected to a word line and one of the source or drain is connected to a bit line. The cell capacitor has a lower or storage electrode and an upper or plate electrode. The storage electrode is connected to the other of the source or drain and the plate electrode is connected to a reference potential conductor. The cell transistor is, when selected, turned “on” by an active level of the word line to read or write data from or into the cell capacitor via the bit line.
As was described previously, the cell capacitor, 700 , comprises a first electrode, 704 , formed on substrate, 701 . The first electrode, 704 , is connected to the source or drain of the cell transistor, 702 . For illustrative purposes, the first electrode has been connected to the source, 712 , in this example. As discussed previously, first electrode, 704 , may be subjected to an anneal in a reducing atmosphere before the formation of the dielectric layer if the first electrode is a conductive metal oxide such as MoO 2 . Crystalline, doped high k first dielectric layer, 706 , is formed on top of the first electrode. If the crystalline, doped high k first dielectric layer is TiO 2 , then the first dielectric layer will be lightly or non-doped so that the rutile phase of TiO 2 can be formed on the bottom electrode. Amorphous, doped high k second dielectric layer, 708 , is formed on top of the first dielectric layer. As discussed previously, the second dielectric layer may be doped. If the second dielectric layer is ZrO 2 , then the second dielectric layer will be highly doped so that it will remain amorphous (<30% crystalline) after subsequent anneal steps. Typically, the bilayer dielectric material is then subjected to a PDA treatment. The second electrode layer, 710 , is then formed on top of the bilayer dielectric material. When the second dielectric layer is ZrO 2 , the second electrode is typically TiN. This completes the formation of the capacitor stack. Typically, the capacitor stack is then subjected to a PMA treatment.
Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed examples are illustrative and not restrictive. | A method for forming a DRAM MIM capacitor stack having low leakage current and low EOT involves the use of a first electrode that serves as a template for promoting the high k phase of a subsequently deposited first dielectric layer. The first high k dielectric layer comprises a doped material that can be crystallized after a subsequent annealing treatment. An amorphous, doped high k second dielectric material is form on the first dielectric layer. The dopant concentration and the thickness of the second dielectric layer are chosen such that the second dielectric layer remains amorphous after a subsequent annealing treatment. A second electrode layer compatible with the second dielectric layer is formed on the second dielectric layer. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser. No. 11/240,959, entitled “Method for Making Reduced Fat Potato Chip” and filed on Sep. 30, 2005, now pending.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to an improved method for the production of potato chips and more particularly to a method for making potato chips which are similar in taste and texture to prior art potato chips produced by a traditional process but with less fat content.
[0004] 2. Description of Related Art
[0005] Commercial production of potato chips typically involves a continuous process wherein sliced potatoes are continuously introduced into a vat of frying oil at a temperature of about 365° F. (about 185° C.) or higher, conveyed through the oil by paddles or other means, and removed from the oil after about two and one-half to three minutes of frying by an endless conveyor belt when the moisture content of the chips has been reduced to about 2% by weight or less. The resulting product generally has texture and flavor characteristics which are usually recognizable by consumers as typical commercially produced continuous process potato chips.
[0006] The typical steps used in making prior art potato chips in this manner involve first peeling the potatoes, then slicing the potatoes, washing and/or blanching the potato slices, drying the potato slices, and then frying the potato slices by emersion in an edible oil or fat heated at an appropriate temperature. After frying, the potato chips can be seasoned with salt and other seasonings and packaged for sale to consumers. Potato chips manufactured in this way typically comprise 30% to 40% or even higher fat content by weight. This fat is picked up during the frying process when the chips are immersed in edible oil or fat and cooked.
[0007] The oil content of potato chips is important for many reasons. Most important is its contribution to the overall organoleptic desirability of potato chips, however from the standpoint of good nutrition, it is desirable to maintain a low level of oil or fat in chips. Further, a high oil content renders the chips greasy or oily and hence less desirable to consumers. On the other hand, it is possible to make chips so low in oil that they lack flavor and seem harsh in texture. A happy medium can be achieved by reducing the oil content in a chip so that the objectives of using less oil is met and consumers interested in reducing their intake of both fats and calories can be satisfied with an organoleptically pleasing snack food.
[0008] Numerous attempts have been made in the prior art to reduce the oil content in potato chips. Some attempts involve pre-treating the potato slices prior to frying. Other attempts involve treating the chips after frying, and some attempts use both pre- and post-treatments. However, past attempts at producing lower oil content chips are either expensive, or have failed to maintain the desired organoleptical properties such as taste and texture that have become familiar to consumers of traditional potato chips having higher fat or oil contents.
[0009] For example, U.S. Pat. No. 4,749,579 teaches a process for producing potato chips having a fat content lower than 32% by weight. The '579 patent discloses a pre-treatment process whereby potato slices are washed in a salt or brine solution. The potato slices are dried and potato slices are pre-heated with infrared radiation prior to being sent to the fryer. This process however has been proven to reduce fat in the end product very inconsistently. The '579 patent even discloses that the resultant chip has a fat content in the range of 26% to 32% by weight compared with a prior art oil content of 38%. Further, the '579 patent requires an infrared radiation step, thus adding equipment and processing expenses.
[0010] Another prior art attempt for making a low oil potato chip by pre-fry treatment is disclosed by U.S. Pat. No. 4,917,919, which teaches coating a potato chip with an aqueous, polyvinylpyrrolidone. Unfortunately, the moisture content of the finished product is about 4% by weight, raising concerns of shelf stability.
[0011] U.S. Pat. No. 4,933,199, assigned to the same Assignee as the present invention, involves treating a fried potato chip in a de-oiling unit to lower the oil content of the chip and further treating the chip in a dehydrating unit to lower the moisture content of the chip. Unfortunately, each unit operation can add substantial capital costs as well as operating cost to the process. Further, the '199 patent indicates that attempting to de-oil potato slices to produce low oil potato chips and simultaneously arrive at a desired final moisture content has been found to be difficult to achieve in the same unit. The '199 patent indicates that optimized de-oiling and optimized final moisture content are not arrived at simultaneously.
[0012] Similarly, U.S. Pat. No. 4,721,625 uses a post-fry saturated steam treatment to reduce the oil content of the potato slices. A saturated steam blasting process, however, generally results in a pick up of moisture by the cooked slices due to condensation. As a result, the cooked slices require a subsequent drying unit operation. As previously indicated, this subsequent drying operation involves substantial economic capital and operating outlays.
[0013] Another prior art solution to making a low oil potato chip is illustrated by U.S. Pat. No. 4,537,786, also assigned to the same Assignee as the present invention. The '786 patent teaches that thicker than normal slicing can reduce oil uptake during frying. The '786 patent process discloses: frying potato slices in oil at a lower than normal temperature of between about 280° F. and 320° F., removing the potato slices from the fryer when the moisture content is about 3% to about 15% by weight, orienting the potato slices on edge, and contacting the fried potato slices for about 1 to about 10 minutes with a stream of hot air. This hot air removes the excess oil as well as finishes cooking the chip. However, hot air tends to accelerate oxidation of the oil reducing shelf life dramatically.
[0014] Another prior art solution for a low oil potato chip is disclosed in U.S. Pat. No. 4,277,510, a process for making low oil potato chips by drying the slices in a monolayer, contacting the resultant dried potato slices with steam, and frying the steam-treated potato slices. Unfortunately, according to U.S. Pat. No. 4,721,625 (discussed above), the pre-drying of the product in the '510 patent results in a glassy texture, case hardened product that has a raw, green flavor, which is different in taste and texture from regularly fried potato chips.
[0015] Several other efforts have been made to reduce the fat in potato chips by limiting the exposure to frying in oil and even by baking the chips and then seasoning them to attempt to produce a chip that is acceptable to consumers used to eating fried potato chips. These efforts have met with limited success, often involving expensive non-traditional processing steps or resulting in a product that does not provide similar desirable characteristics as compared to a fried potato chip.
[0016] Consequently, there is a need in the industry for an efficient process for making a reduced-fat potato chip which uses existing equipment, adds little to the cost of producing the chip, yet produces a potato chip that is quite similar in characteristics to a potato chip produced by a standard prior art method.
SUMMARY OF THE INVENTION
[0017] The invention provides a method for making potato chips using standard equipment used in this industry, with little additional cost, that produces a potato chip having a reduced fat content, but is otherwise very similar to potato chips made by standard prior art methods. The instant invention involves a marination step that occurs prior to a prior art frying step. This marination step occurs in a brine solution to which acacia gum has been added. The sliced potato chips or pieces are marinated in this brine and acacia gum solution for, in one embodiment, approximately 9 to 14 seconds before being dried and fried in accordance with prior art methods. The resultant potato chip, in one embodiment, consistently contains by weight approximately 24.5% fat, which is a 25% or better reduction in the fat of the chip as compared to chips made without the marination step. The equipment used for the marination step can be the same equipment used for blanching sliced chips in water. In an alternative embodiment, the marination step with the brine and acacia gum solution can take the place of a blanching step, thus producing one processing step. The present invention provides a more economical method for making potato chips by a continuous method having desirable texture and taste properties with reduced fat content.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
[0019] FIG. 1 is a schematic representation of the method step of one embodiment of the present invention.
DETAILED DESCRIPTION
[0020] An embodiment of the innovative invention will now be described with reference to FIG. 1 . FIG. 1 is a schematic representation of the method step of one embodiment of the present invention. Raw potato stock is first sliced 102 (this can include a separate peeling step prior to the slicing step or the skin can be retained on the potato during the slicing step) in accordance with prior art techniques and using prior art equipment. These sliced raw potato pieces are then washed 104 during a washing and/or blanching step. Again, this washing step 104 occurs using prior art equipment using prior art methods and techniques. For example, one suitable slice washer is the “Potato Slice Speed Washer” or the “Gentle Wash” supplied by Heat & Control, Inc. The potato slices are then transported, typically via conveyor, to the marination step 106 . If desired, excess moisture adsorbed to the surface of the potato slices can be removed between the washing 104 and marination 106 steps. Excess moisture removal can be accomplished using prior art de-watering devices and techniques such as drip-drying along a perforated belt conveyor or surface, and/or blasting air (which can be heated for greater effect) across or upon the surface of the potato slices. Example de-watering devices suitable for the instant invention include the “Air Knife” and the “Air Sweep® Water Removal System” supplied by Heat & Control, Inc.
[0021] In one embodiment, for example, the marination step 106 applies an aqueous brine solution in a controlled manner that allows the food to obtain a crispy texture. The brine application system can be a continuous flow of brine that is then discharged, or such flow of brine can be recycled and either continuously replenished or replenished by batch. Such flow of brine can be either concurrent or countercurrent with respect to the direction of movement of the potato pieces.
[0022] If desired, a brine application system, which can be used in addition to or in combination with a slice-washing step, can also be used wherein substantially no effluent by-product is created. One such example is described in co-pending U.S. application Ser. No. 10/109,059 and published in Publication No. US 2003/0183092 for Barber et al., which application has been assigned to the same Assignee as the current invention. For instance, Barber et al. teach that potato slices are supplied in a continuous stream to one or more water baths in order to remove excess surface starch from the slices. Water is discharged from the bath and, if desired although not necessary, is passed through a filter and starch recovery system. The washed slices are removed from the bath by a conveyor system. An air knife system, including a blower fan and a vacuum fan, is disposed adjacent the conveyor system to remove excess surface moisture (i.e., water) from the slices being removed from the bath. The washed slices are then supplied to a brine bath tank containing an amount of brine solution having a specific concentration of a chloride compound, for example, NaCl. The chloride compound concentration of the brine solution in one particular embodiment is about 4% NaCl, where the concentration is determined as grams per liter (i.e., kilogram) of water. The chloride compound concentration, however, can vary depending on the characteristics of the raw potato used and the desired end product. The residence time that the slices spend marinating in the brine bath tank in order to assure proper wetting of the slices by the NaCl solution is on the order of a few seconds. Subsequently, the potato slices exit the brine bath tank with a surface moisture of 20-25% by weight of potato slice in the form of surface brine solution. NaCl is replaced in the brine bath tank by adding a 25-26% saturated NaCl solution to the tank at a rate of about a gallon per minute. The slices then pass through an air knife system, which takes the surface moisture of the marinated slices down to 14-16% by weight of the potato slices. The turnover rate for the brine bath tank in this particular embodiment is about 35 minutes, but this may vary. Peroxyacetic acid is added in a 15% solution to the brine bath tank to maintain a preferred concentration of at least about 5 ppm and preferably at least about 15 ppm. The slices are then fried into chips preferably having a NaCl content of about 3% by weight of the chip due to the application of the brine solution. The amount of NaCl on the finished chips is controlled by controlling the concentration of NaCl in the brine bath tank and by controlling the amount of surface solution removed from the marinated slices by the air knife system.
[0023] The marination step 106 in the instant invention involves subjecting the potato slices to an aqueous brine solution to which acacia gum has been added as well. In one embodiment, the potato slices fall into the brine solution on a moving, perforated belt or conveyor, which belt then removes the potato slices from this brine solution shortly thereafter. Any product-submerging, product-washing, or other solid-and-liquid interfacing devices can be used in the marinating step 106 . Furthermore, if desired, the device for marinating can be identical to the device used in the washing step 104 . Example devices suitable for the marination step 106 include the “Potato Slice Speed Washer” and the “Gentle Wash” supplied by Heat & Control, Inc. Such marinating systems may also provide for starch filtration and liquid recycle.
[0024] In a preferred embodiment, the brine solution comprises an aqueous solution containing NaCl in amounts ranging from about 1% by weight to an amount which saturates the aqueous solution with the NaCl. In a preferred embodiment, the amount of NaCl in the aqueous solution ranges from about 3.5% by weight to about 4% by weight. The brine solution also comprises acacia gum, which is a food grade material that is highly soluble in water and is also referred to as arabic gum. In a preferred embodiment, the acacia gum in a powdered form is added to the brine solution after the addition of the NaCl in an amount up to 10% by weight of acacia gum to the aqueous solution. A preferred concentration of the acacia gum in the brine solution is between about 3% by weight to about 6% by weight. A most preferred embodiment of the invention involves a weight percentage of the acacia gum in the brine solution of about 4% to about 5%. Given a weight concentration of about 4% to about 5% acacia gum in the brine solution, the marination step 104 , in a preferred embodiment, involves immersing the sliced potato pieces in the brine/acacia solution for about 5 seconds to about 20 seconds, or, more preferably, for about 9 seconds to about 14 seconds. In an alternative embodiment, the potato pieces can be washed and/or blanched during the marination step 106 , rather than during a separate step 104 . The marination step 104 is simply performed at ambient temperature, but warmer temperatures or cooler temperatures may be used alternatively. In fact, an elevated temperature of the brine solution may help the potato cells better absorb the salt and acacia gum. Marinating at ambient temperature, however, preserves energy and additional expense that would otherwise be necessary to heat and/or cool the brine solution.
[0025] Note that the term “acacia gum” as used in the instant application refers generally to the exudate of the acacia tree and its related species. Synonyms for acacia gum include, but are not limited to: gum Arabic; gum acacia; gum mimosa; gummi mimosae; gummi arabicum. Varieties of acacia gum include, but are not limited to: Senegal gum; Morocco gum, also called Mogador or Barbary gum; Cape gum; Australian gum, also called Wattle gum; India gum, also called East India gum; Suakin gum, also called Savakin gum, Talca or Talha gum; Sennaar gum, also called Sennari gum; Mezquite gum; Hogg gum, also called Doctor gum; Chagual gum. Acacia gum is largely composed of calcium arabate and includes a mixture of salts of calcium, magnesium, and potassium. These salts result from the combination of those elements with Arabic acid. In a preferred embodiment, the acacia gum has been purified using only physical methods and no extraction processing, no chemical modification, and no enzymatic modification.
[0026] In a preferred embodiment, the particular variety and brand of acacia gum used is the “Fibregum Standard IRX 60487” supplied by Colloides Naturels de Mexico, S.A. de C.V. Empresa Subsidiaria de Coloïdes Naturels International. The Fibregum Standard IRX 60487 is derived from purified and spray-dried acacia fibre, and its properties, as measured under the AOAC method, are as follows:
[0000]
pH - MO 4.10.31
Solution at 25% in water
4.1-4.8
Total ashes - MO 4.10.46
Maximum
4%
Viscosity - MO 4.10.57
Solution at 25% in water at
60-130 cP
room temperature, measure
with Brookfield LVF 60 rpm
Colour - MO 4.10.73
Solution at 25% in water,
15
measured with Loyibond,
maximum
Total plate county - MO
Maximum
5000/g.
4.10.15
[0027] Note, however, that while a preferred embodiment uses acacia gum with the properties described above, other varieties of acacia gum are also suitable for the instant invention.
[0028] The remainder of the steps involved in the invention again involve prior art methods using prior art equipment. After leaving the marination step 106 , the potato pieces are then dried or otherwise de-watered 108 (meaning some of the surface water is removed) using prior art methods, such as blowing the pieces with a fan to allow some de-watering of the pieces prior to the frying step 110 . For example, one suitable de-watering device is the “Air Sweep® Water Removal System” supplied by Heat & Control, Inc., which provides a vacuum beneath the perforated conveying belt (for pulling superficial moisture away from the product) in addition to an air blower above the belt (also for removing superficial moisture from the product). The potato pieces are then fried 110 and seasoned 112 before being packaged during a packaging step 114 . The resultant product given the parameters detailed for a preferred embodiment is a potato chip having a fat content of about 24.5% by weight. Chips made using identical processing steps without the marination step typically have a fat content of about 33% by weight. This is a substantial reduction in the fat of a potato chip using a simple and inexpensive method without adversely affecting the color, taste, and organoleptic properties of the final product. The reduction in fat content has been found to be consistent and is attributed to the combination of the exposure to both NaCl and acacia gum, as a marination step in NaCl alone results in inconsistent fat levels in the final product.
[0029] While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. | A method for making potato chips involving a marination step in a brine and acacia gum solution prior to frying. Potato pieces or slices are immersed for a short period of time in a brine solution that comprises soluble acacia gum. This immersion marinates the potato pieces prior to a frying step. The resultant potato chips, after frying, have a reduced fat content but exhibit otherwise very similar characteristics to a potato chip made by prior art frying methods. | 0 |
[0001] This application claims priority from copending provisional application Serial No. 60/461,647, filed Apr. 9, 2003, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND TO THE INVENTION
[0002] This invention relates to a process for the large scale preparation of 3-cyano-6-alkoxy-7-nitro-4-quinolones, which are intermediates for the preparation of protein tyrosine kinase (PTK) inhibitors useful in the treatment of cancer.
[0003] The two most frequently used synthetic methods for the preparation of 3-cyano-4-quinolones or 3-carboalkyloxyquinolones are intramolecular Friedel-Crafts reactions and electrocyclic ring closures of N-(2-carboxyvinyl)-aniline derivatives. Friedel-Crafts conditions work well for electron rich anilines, moderately for unsubstituted anilines, and poorly or not at all for electron-deficient anilines and are especially not useful for large scale preparation of 3-cyano-4-quinolones utilizing electron deficient anilines. The electron withdrawing groups of the aniline reduce the nucleophilicity of the aromatic ring to the point that side reactions compete with, if not dominate, the desired intramolecular condensation. Thermal conditions for electrocyclic ring closures of N-(2-carboxyvinyl)-aniline derivatives typically require temperatures in excess of 240° C. However, the construction of 3-cyano-4-quinolones has been achieved by electrocyclic ring closure reactions of N-(2-carboxyvinyl) aniline derivatives by heating to 260° C. in diphenyl ether (U.S. Pat. No. 6,002,008; WO 98/43960). In particular, there are several deficiencies associated with electrocyclic ring closures for preparing quantities of material on a process scale. Typically, reactions are run at high dilution (66:1) resulting in an inefficient large-scale process due to low throughput. Further, thermal decomposition of either the final product and/or the starting material compromises the purity of the final product as a result of the high temperature reaction conditions. Additionally, equipment necessary to perform high temperature reactions safely on larger scale is expensive and not available in a typical laboratory or plant environment.
[0004] The production of 3-cyano-4-quinolones by electrocyclic ring closure suffers from all of the problems mentioned above, especially thermal decomposition of the desired final product or the starting material. For example, it is known that 7-ethoxy-4-hydroxy-6-nitroquinoline-3-carbonitrile decomposes at 240° C. while the minimum temperature required for cyclization is 256° C.
[0005] Thus, there is a need in the art for a process that addresses and preferably overcomes the high temperature cyclization, which results in thermal decomposition.
[0006] The following experimental details are set forth to aid in an understanding of the invention, and are not intended, and should not be construed to limit in any way the invention set forth in the claims that follow thereafter.
BRIEF SUMMARY OF THE INVENTION
[0007] This invention provides a process for the production of a 3-cyano-6-alkoxy-7 nitro-4-quinolone comprising:
[0008] a) reacting a substituted anthranilate of formula (I) with dimethylformamide dimethyl acetal:
[0009] wherein R and R 1 are alkyl;
[0010] to obtain a compound of formula (II):
[0011] b) condensing the compound of step a) with t-butylcyanoacetate to obtain a compound of formula (III):
[0012] c) hydrolyzing the compound of step b) to yield compound of formula (IV):
[0013] d) decarboxylating the compound of step c) to a compound of formula (V):
[0014] e) cyclizing the compound of step d) in the presence of a base to obtain a 3-cyano-6-alkoxy-7-nitro-4-quinolone of formula:
[0015] When used herein the term alkyl denotes a straight or branched chain alkyl group, e.g. a C1-C6 alkyl group, preferably a C1-C4 alkyl group, more preferably Me, Et, n-Pr, I—Pr, n-Bu, most preferably Me or Et. R and R 1 can be the same or different. The present invention encompasses all tautomeric forms of the compounds as well as mixtures of the tautomeric forms.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The invention described herein for the production of 3-cyano-6-alkoxy-7-nitro-4-quinolones obviates the high temperature (256° C.) and the low throughput (66:1) high dilution issues hereinbefore described. These reaction conditions allow the cyclization reaction to be performed in standard processing equipment.
[0017] The process of the invention is shown in Scheme I.
[0018] As described in Scheme I, substituted anthranilate 1 where R is alkyl, is reacted with dimethylformamide dimethyl acetal (DMF-DMA) or with about 1 to 5 equivalents of dimethylformamide dimethyl acetal in a alcoholic solvent to yield N,N-dimethylamidine 2. In a preferred embodiment the concentration of (DMF-DMA) is 1 to 2 equivalents. Preferred conditions for this reaction use about 1.2 equivalents of dimethylformamide dimethyl acetal in t-butanol at about 50° C. to about 120° C. with a preferred temperature of 80° C. In a preferred embodiment the reaction allows for simple isolation of N,N-dimethylamidine 2 by cooling the reaction mixture to allow the product to precipitate and collecting the precipitate by filtration. This procedure provides a near quantitative yield of N,N-dimethylamidine 2 of sufficient purity for use in the subsequent step without further purification. In an additionally preferred procedure substituted anthranilate 1 is reacted with dimethylformamide dimethyl acetal at reflux (about 110° C.) and the N,N-dimethylamidine 2 isolated after dilution with water, by filtering and drying the collected product.
[0019] The condensation reaction of N,N-dimethylamidine 2 with t-butylcyanoacetate may be performed using acetonitrile, acid, toluene, or alcoholic solvent at about 20° C. to about 110° C. to obtain N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3. In a preferred embodiment condensation is conducted by the addition of t-butanol at about 25° C. to about 35° C. with about 1.5 to about 2.0 equivalents of t-butylcyanoacetate which provides high quality material (>98% high pressure liquid chromatography (HPLC area)) in high yield (90-99%).
[0020] The hydrolysis of the N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 may be accomplished by the use of an acid in a solvent or using acetic acid directly as solvent at about 20° C. to about 110° C. In a preferred embodiment hydrolysis comprises treating N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 with a catalytic amount of triflic acid in acetonitrile at about 20° C. to about 30° C. to produce N-(2-cyano-2-carboxyvinyl)anthranilate 4 as characterized by NMR. The N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 may optionally be heated to 180° C. in o-dichlorobenzene (ODCB) to remove the t-butyl ester and afford N-(2-cyano-2-carboxyvinyl)anthranilate 4.
[0021] The decarboxylation of N-(2-cyano-2-carboxyvinyl)anthranilate 4 may be accomplished under either acidic or basic conditions to yield N-(2-cyano-vinyl)anthranilate 5. In a preferred embodiment acids include acetic acid and p-toluenesulfonic acid, bases include diisopropylethylamine, pyridine, or diazobicyclo[2.2.3]undecene (DBU), in suitable solvents which include acetonitrile, acetic acid, pyridine, and dimethylacetamide at about 80° C. to about 140° C. If the thermally induced hydrolysis of N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 to N-(2-cyano-vinyl)anthranilate 5 in o-dichlorobenzene (ODCB) is performed in the presence of a catalytic amount of a suitable base which includes diisopropylethylamine(DIEA) then N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 is converted directly to N-(2-cyano-vinyl)anthranilate 5. In a preferred embodiment DBU in acetonitrile at about 80° C. is used.
[0022] The intramolecular anionic cyclization (cyclizing) of N-(2-cyano-vinyl)anthranilate 5 to 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 may be accomplished with about 2 to 13 equivalents of base in solvent. In a preferred embodiment the base includes DBU, NaH, piperidine, dimethylaminopyridine (DMAP) or potassium t-butoxide (KotBu). In a preferred embodiment solvents include acetonitrile, diphenylether, ODCB, THF/xylene mixtures, toluene, N,N-dimethylformamide (DMF), propionitrile or isopropanol. In a preferred embodiment dilution ratios of solvent:substrate are about 15 to about 30:1 at about 60° C. to about 140° C. The preferred procedure to prepare 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 is to treat N-(2-cyano-vinyl)anthranilate 5 with about 3 to 5 equivalents of DBU in acetonitrile at about 80° C. for about 4 to 5 hours and quenching with aqueous HCl.
[0023] A more preferred procedure to produce 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 from N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 is to conduct the hydrolysis, decarboxylation and intramolecular cyclization reaction sequentially in the same vessel without isolation of N-(2-cyano-2-carboxyvinyl)anthranilate 4 or N-(2-cyano-vinyl)anthranilate 5. The more preferred process for producing 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 is comprised of hydrolyzing N-(2-cyano-2-t-butoxycarbonyl-vinyl)anthranilate 3 with about 0.2 to about 0.3 equivilents of triflic acid in acetonitrile at about 20° C. to about 30° C. for about 5 to 60 min followed by the addition of about 3 to 5 equivalents of DBU and refluxing the reaction mixture for about 4 to 5 hours. The 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 is isolated by diluting the reaction mixture with water and collecting the resulting precipitate by filtration. The collected precipitate is triturated with ethyl acetate to provide 3-cyano-6-alkoxy-7-nitro-4-quinolone 6 as beige to brown solid (70-80% yield, >98% by 1 H NMR).
[0024] The invention claimed herein provides 3-cyano-7-alkoxy-6-nitro-4-quinolones by combining steps and without the need for high temperature cyclization. 3-Cyano-6-alkoxy-7-nitro-4-quinolone 6 is provided in good overall yield (70% for 5 transformations performed in two single reactor operations, with purity >98% by HPLC and 1 H NMR).
[0025] For purposes of this invention an acid is a molecular entity or chemical species capable of donating a proton or capable of forming a covalent bond with an electron pair. Preferred acids include acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid and triflic acid.
[0026] For purposes of this invention a solvent is the term applied to the whole initial liquid phase containing the extractant. The solvent may contain only one extractant or it may be a composite homogeneous mixture of extractant(s) with diluent(s). In a preferred embodiment the solvent includes toluene, acetonitrile, tetrahydrofuran (THF), dimethylacetamide, acetic acid, pyridine, diphenylether, ODCB, THF/xylene mixtures, toluene, N,N-dimethylformamide (DMF), propionitrile or isopropanol.
[0027] For purposes of this invention a base is a chemical species or molecular entity having an available pair of electrons capable of forming a covalent bond with a proton or with the vacant orbital of some other species. In a preferred embodiment a base includes diisopropylethylamine, pyridine, or diazobicyclo[2.2.3]undecene (DBU), NaH, piperidine, dimethylaminopyridine (DMAP) or potassium t-butoxide (KOtBu).
[0028] For purposes of this invention the term “alkyl” includes both straight and branched alkyl moieties, preferably of 1 to 6 carbon atoms.
[0029] In order to facilitate a further understanding of the invention, the following non-limiting examples illustrate the process of the present invention.
EXAMPLE 1
2-[[(Dimethylamino)methylene]amino]-4-ethoxy-5-nitrobenzoic acid, methyl ester
[0030] A 3-L round-bottomed flask under N 2 equipped with an overhead stirrer, a condenser and a thermocouple is charged with 2-amino-4-ethoxy-5-nitrobenzoic acid methyl ester (80 g, 333 mmol) and N,N-dimethylformamide dimethyl acetal (500 mL). The reaction mixture is heated to reflux (100° C.). Once the thick slurry becomes homogeneous and the reaction is complete, the reaction mixture is cooled to 25 to 30° C. The reaction mixture is diluted with water (3 L) and the resulting suspension is filtered. The filter cake is washed with water (3×500 mL) and dried under vacuum (50 mm Hg) at 55° C. to provide the title compound as an off-white solid (89.6 g, 91% yield, >90% purity by NMR integration). 1 H NMR (300 MHz, DMSO-d 6 ): 8.23 (s, 1H), 7.81 (s, 1H), 6.71 (s, 1H), 4.22 (q, J=7 Hz), 3.68 (s, 3H), 3.09 (s, 3H), 2.97 (s, 3H), 1.40 (t, J=7 Hz, 3H).
EXAMPLE 2
2-Cyano-3-(5′-ethoxy-2′-methoxycarbonyl-4′-nitrophenyl)amino-2-propenoic acid t-butyl ester
[0031] A 3-L round-bottomed flask under N 2 equipped with an overhead stirrer, a condenser and a thermocouple is charged with 2-[[(dimethylamino)methylene]amino]-4-ethoxy-5-nitrobenzoic acid, methyl ester (68 g, 230 mmol), t-butanol (500 mL) followed by t-butylcyanoacetate (65 g, 460 mmol). The reaction mixture is heated to reflux. After 4 hours the reaction is cooled to room temperature and the suspension is filtered. The filter cake is washed with heptane (2×100 mL) and dried under vacuum (50 mm Hg) at 40° C. to provide the title compound as a beige solid (83 g, 91% yield, >98% purity by NMR). 1 H NMR (300 MHz, DMSO-d 6 ): 12.7 (d, J=12.9 Hz, 1H), 8.77 (d, J=12.9 Hz, 1H), 8.50 (s, 1H), 7.47 (s, 1H), 4.37 (q, J=7 Hz, 2H), 3.91 (s, 3H), 1.52 (s, 9H), 1.40 (t, J=7 Hz, 3H).
EXAMPLE 3
2-Cyano-3-(5′-ethoxy-2′-methoxycarbonyl-4′-nitrophenyl)amino-2-propenoic acid t-butyl ester
[0032] A 3-L round-bottomed flask under N 2 equipped with an overhead stirrer, a condenser and a thermocouple is charged with 2-amino-4-ethoxy-5-nitrobenzoic acid methyl ester (100 g, 0.416 mol) and N,N-dimethylformamide dimethyl acetal (59.5 g, 0.499 mol) and t-butanol (800 mL). The reaction mixture is heated to reflux for 1.5 h. The reaction mixture is cooled to 22 to 35° C. and the t-butylcyanoacetate (117 g, 0.832 mol) added. The reaction mixture is stirred at 20 to 30° C. for 2 h. The precipitate is collected by suction filtration, washed with heptane (500 mL), then dried to constant weight under reduced pressure (50 mm Hg)) at 45° C. overnight to provide the title compound as a off-white solid (162.9 g, 95% yield, >95% purity by HPLC). 1 H NMR (300 MHz, DMSO-d 6 ): 12.7 (d, J=12.9 Hz, 1H), 8.77 (d, J=12.9 Hz, 1H), 8.50 (s, 1H), 7.47 (s, 1H), 4.37 (q, J=7 Hz, 2H), 3.91 (s, 3H), 1.52 (s, 9H), 1.40 (t, J=7 Hz, 3H).
EXAMPLE 4
N-(2-cyanvinyl)-2-amino-4-ethoxy-5-nitrobenzoic Acid
[0033] A 500-mL round-bottomed flask under N 2 equipped with a stirbar, a condenser and a thermocouple is charged with (Z)-2-Cyano-3-(5′-ethoxy-2′-methoxycarbonyl-4′-nitrophenyl)amino-2-propenoic acid t-butyl ester (20 g, 51.1 mmol), N,N-diisopropylethylamine (1 mL, 5.72 mmol) and o-dichlorobenzene (200 mL). The reaction is heated to reflux (180° C.). After 7.5 hours the reaction was complete as evidenced by thin layer chromatography. The reaction is cooled to room temperature and dilute hexane (500 mL) to precipitate the crude product. The solid is isolated by filtration to provide the title compound as a beige powder (11.7 g, 79% yield of 65:35 stereoisomers, 94% purity by NMR). 1 H NMR (300 MHz, DMSO-d 6 ): 11.1 (d, J=12.7 Hz, 0.65H), 10.6 (d, J=12.9 Hz, 0.35H), 8.47 (s, 0.65H), 8.37 (s, 0.35H), 8.29 (dd, J=13.4, 12.9 Hz, 0.35H), 8.16 (dd, J=12.7, 8.5 Hz, 0.65H), 7.13 (s, 1H), 5.49 (d, J=13.4 Hz, 0.35H), 4.97 (d, J=8.4 Hz, 0.65H), 4.38-4.28 (m, 2H), 3.90 (s, 1.95H), 3.88 (s, 1.05H), 1.39 (t, J=7 Hz, 3H).
EXAMPLE 5
7-ethoxy-4-hydroxy-6-nitroquinoline-3-carbonitrile
[0034] A 100-mL round-bottomed flask equipped with an overhead stirrer, a condenser and a thermocouple is charged with (Z)-2-Cyano-3-(5′-ethoxy-2′-methoxycarbonyl-4′-nitrophenyl)amino-2-propenoic acid t-butyl ester (2.5 g, 6.3 mmol) and acetonitrile (50 mL). The triflic acid (0.12 mL, 0.21 mmol) is added to the heterogeneous reaction medium. Upon disappearance of the starting material as evidenced by TLC (20% EtOAc/hexane), the DBU (4.0 mL, 4.25 mmol) is added to the reaction mixture. The reaction is then heated to reflux and monitored for completion (>95% by HPLC—Phenomenex 3 micron Phenyl-hexyl column (150×4.6 mm)). The reaction is then quenched with 10% HCl (100 mL) and diluted with water (400 mL). After stirring for 15 minutes at room temperature the suspension is filtered and the collected solid allowed to “air” dry. The collected solid is suspended in ethyl acetate (25 mL) at room temperature and filtered again and allowed to “air” dry. This procedure provides 1.15 g (70%) of the title compound as a beige solid that is >95% product by NMR integration. 1 H NMR (300 MHz, DMSO-d 6 ): 12.9 (s, 1H), 8.79 (s, 1H), 8.51 (s, 1H), 7.24 (s, 1H), 4.27 (q, J=7 Hz, 2H), 1.41 (t, J=7 Hz, 3H). | There is provided a process for the preparation of 3-cyano-6-alkoxy-7-nitro-4-quinolone intermediates useful for the preparation of protein tyrosine kinase (PTK) inhibitors which are useful in the treatment of cancer of the formula:
wherein R is alkyl(C 1 -C 3 ) prepared by reacting a substituted anthranilate with N,N-dimethylformamide dimethyacetal to obtain a N,N-dimethylamidine which is condensed with t-butylcyanoacetate to obtain a N-(2-cyano-2-t-butoxycarbonylvinyl)anthranilate, which is hydrolyzed to yield a N-(2-cyano-2-carboxyvinyl)anthranilate followed by decarboxylating to obtain a N-(2-cyano-2-carboxyvinyl)anthranilate followed by cyclizing to obtain a 3-cyano-6-alkoxy-7-nitro-4-quinolone. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of preparing a recording head to be used in an ink jet recording device which performs recording by forming droplets of ink by discharging ink and attaching the droplets onto a recording medium such as paper, etc., and to a method of preparing a substrate for constituting the head.
2. Related Background Art
The ink jet recording method is a recording method which performs recording by discharging ink (recording liquid) from a discharge opening provided at an ink jet recording head and attaching the ink onto a recording medium such as paper, etc. This method has many advantages. It generates little noise, is capable of high speed recording, and yet recording can be practiced on plain paper, etc., without use of a special recording paper. Various types of recording heads have been developed.
Among them, the recording head of the type which discharges ink from a discharge opening by utilizing heat energy as disclosed in Japanese Laid-open Patent Publication No. 54-59936 (corresponding to U.S. Pat. No. 4,723,129) and German Laid-open Patent Publication (DOLS) No. 2843064 has such advantages as good response to recording signals, easy multi-formation of discharge openings, etc.
Principal structure of a recording head of the type utilizing heat energy as the ink discharging energy are exemplarily shown in FIGS. 1A and 1B.
The recording head has a structure formed by bonding a substrate comprising an electrothermal transducer as heat generating means provided for converting electrical energy to heat energy to be utilized for ink discharge, arranged on a surface of a support 1 exhibiting insulating properties, and further, if necessary, an upper layer 4 as the protective layer is provided at least on the heat-generating resistor 2 and electrodes 3 positioned below a liquid path 6 and a liquid chamber 10 having an ink supply opening 9. Covering member 5 having a recession for the liquid path 6 and the liquid chamber 10, etc. formed thereon.
The discharging energy for ink discharge in this recording head is imparted by the electrothermal transducer having a pair of electrodes 3 and a heat-generating resistor 2 connected electrically to these electrodes. That is, when current is applied on the electrodes 3 to generate heat from the heat generating portion 8 of the heat-generating resistor 2, the ink in the liquid path 6 near the heat-generating portion 8 is momentarily heated to generate bubbles thereat, and through volume change by momentary volume expansion and shrinkage by generation of the bubbles, ink is discharged as a droplet from a discharge opening.
As the representative method for preparing the electrothermal transducer of the substrate in such constitution of the recording head as described above, there has been known the method as disclosed in Japanese Laid-open Patent Publication No. 59-194859 according to the steps, in which at first a heat-generating resistor layer comprising HfB 2 , etc. and an electrode layer comprising Al, etc. are successively laminated on an appropriate support. Next the electrode layer is etched to a predetermined shape by use of an etchant, and then the heat-generating resistor layer is further etched to a predetermined shape with the use of an etchant.
Whereas, according to such method, during etching of the heat-generating resistor layer, the etchant will attack the side face of the electrode layer already subjected to patterning, whereby curling or defect will sometimes occur on the side surface of the electrode layer. Also, as shown in FIG. 2, if the heat-generating resistor layer 2 is overetched so that the side surface of the electrode layer 3 is exposed, when a protective layer 4 is further provided, its coverage capacity will become extremely poor, giving rise to defective results such as dissolution of the electrodes by penetration of ink when assembled in the recording head.
As the means for solving such problems, for example, there is the method of subjecting the width of the electrode layer 3 to patterning smaller than the width of the heat-generating resistor layer 2 as shown in FIG. 3.
However, such method is not necessarily satisfactory in practical application or in the point of its effect.
More specifically, during patterning of the heat-generating resistor layer 2 and after patterning of the electrode layer 3, it is necessary to provide a resist mask for patterning by registration with good precision on the electrode pattern 3. Particularly, when higher densification is effected by making smaller the arrangement pitch of the heat-generating portion 8 of the heat-generating resistor 2, the difference in width (W) between the electrode layer 3 and the heat-generating resistor layer 2 must be formed on the order of, for example, 1 μm or less, and registration of the resist mask with good precision in such case is technically difficult, whereby generation of defective registration will often occur resulting in lowering of yield.
Also, since patterning of the heat-generating resistor layer is effected in the wet step by use of an etchant, defective patterning of the heat-generating resistor layer due to the peeling of the etching resist or the battery reaction between the heat-generating resistor layer and the electrode layer will sometimes be generated.
SUMMARY OF THE INVENTION
The present invention has been accomplished in view of the aforementioned problems in the prior art, and its object is to provide a method which can prepare an electrothermal transducer with good precision and good yield, and yet can prepare a substrate for an ink jet recording head and a head having the substrate of good quality.
Another object of the present invention is to provide a method of preparing an ink jet head comprising a support, an electrothermal transducer formed on said support and having a heat-generating resistor and a pair of electrodes connected electrically to said heat-generating resistor and a liquid path formed on said support corresponding to the heat generating portion of said electrothermal transducer formed between said pair of electrodes, and communicating with a discharge opening for discharging liquid, which comprises the step of dry etching to pattern the material for said heat-generating resistor provided on said support in the form of a layer.
Still another object of the present invention is to provide a method of preparing a substrate for an ink jet head comprising a support and an electrothermal transducer formed on said support and having a heat-generating resistor and a pair of electrodes connected electrically to said heat-generating resistor, which comprises the step of dry etching to pattern the material for said heat-generating resistor provided on said support in the form of a layer.
Thus, according to the present invention, since the dry etching method which can easily control the state of etching is used for patterning of the heat-generating resistor layer, etching of the electrode layer and the heat-generating resistor layer can be effected with the same resist pattern, whereby no registration working of the mask, as in the prior art, is required and also there occurs no such problem as described above involved in the wet step because it is the dry step.
Particularly, in the dry etching method, strength of etching or its speed can be easily controlled, and over-etching of the heat-generating resistor or side etching of the electrode can be easily prevented or reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are schematic illustrations showing an example of the principal structure of the ink jet recording head, FIG. 1A showing a partial sectional view of the substrate constituting the recording head, and FIG. 1B an exploded view showing the positional relationship between the substrate and the covering member.
FIG. 2 is a partial sectional view showing the state of over-etching in the method of the prior art. FIGS. 3A and 3B are diagrammatic views showing the relationship between the electrode and the heat-generating resistor in the prior art, FIG. 3A being a plan view of the substrate and FIG. 3B being a sectional view at the line X-Y in FIG. 3A.
FIGS. 4A-4F are process diagrams showing the principal steps in the method of the present invention as schematic sectional views of the substrate.
FIG. 5 is a schematic perspective view showing the appearance of an ink jet device equipped with an ink jet head obtained according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, an embodiment of the method of the present invention is described by referring to the drawings.
First, as shown in FIGS. 4A and 4B, a heat-generating resistor layer 2 comprising HfB 2 , etc. and an electrode layer 3 comprising Al, etc. are successively laminated on a support 1 as conventionally practiced.
Next, an etching resist 11 is provided as shown in FIG. 4C.
As the etching resist, one comprising a material which is effective for both etching of the electrode layer and dry etching of the heat-generating resistor layer is suitable because these can be etched with the same resist.
As the material for formation of resist, for example, OFPR 800 (Tokyo Oka), AZ 130 (Hoechst), microposit 1400 (Shipley), etc. may be included, and it may be provided to a predetermined shape on the electrode layer 3 according to the patterning method by use of photolithographic steps, etc.
After the etching resist 11 is thus provided, first the electrode layer 3 is etched as shown in FIG. 4D. The etching may be also effected by the wet step by use of an etchant, provided that etching with good precision is possible, which may be suitably selected depending on the material for forming the electrode layer. As the material for formation of the electrode layer, a material which is not attacked by subsequent dry etching of the heat-generating resistor layer is preferred.
On completion of etching of the electrode layer 3, the heat-generating resistor layer 2 is subjected to dry etching as shown in FIG. 4E.
The operating conditions of dry etching in this case may be suitably selected depending on these materials so that no damage is done to the electrode layer and the heat-generating resistor layer may be formed with good precision and without over-etching or with as little over-etching as possible.
For example, when a boride of such a metal as hafnium, lanthanum, zirconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, vanadium, etc. is used, halogenic gases including, for example, chlorine-type gases such as Cl 2 , BCl 3 , CCl 4 , SiCl 4 , etc. and fluorine-type gases such as CF 4 , CHF 3 , C 2 F 6 , NF 3 , etc. are preferable as an etching gas.
After the electrode layer 3 and the heat-generating resistor layer 2 are thus patterned to desired shapes, the resist 11 is removed from the support 1 as shown in FIG. 4F, and further the predetermined portion of the heat-generating resistor layer is exposed according to the etching step of the electrode layer by use of photolithographic steps to form a heat-generating portion of heat-generating resistor, thus providing an electrothermal transducer on the support. Further, if desired, a protective film comprising SiO 2 , polyimide, etc. is provided to form a substrate for an ink jet recording head.
The substrate obtained can be bonded to, for example, a covering member as shown in FIG. 1B to form a recording head.
The present invention is described in more detail below by referring to Examples.
EXAMPLE 1
First, on a silicon wafer (A4 size) as the support having a SiO 2 film (5 μm) formed on its surface by heat oxidation, HfB 2 was laminated with a layer thickness of 2000 Å as the heat-generating resistor layer by RF Magnetron sputtering, and further Al was laminated with a thickness of 5000 Å as the electrode layer by the EB vapor deposition method.
Next, an etching resist comprising OFPR 800 (produced by Tokyo Oka) was formed on the obtained electrode layer by the photolithographic technique.
By use of the resist thus formed as the mask, first the Al layer was etched with a phosphoric acid-nitric acid type etchant.
Next, the heat-generating resistor layer was etched with the use of RIE using CCl 4 as the reactive gas under the conditions of a gas pressure of 3 Pa, a power of 300 W and an etching speed of 300 Å/min.
In the etching operations, no peeling of resist or defective etching was recognized. Further, as the result of SEM observation after etching, the product had a good sectional shape without large over-etching or side etching of the electrode layer.
Next, the resist was peeled off, and further for the purpose of having a heat-generating resistor exposed at the predetermined portion, a resist (OFPR 800, produced by Tokyo Oka) film was formed at the portion except for the portion corresponding to the portion to be exposed, and this was treated with a phosphoric acid-nitric acid type etchant for Al to etch Al where no resist was provided to complete formation of an electrothermal transducer having a heat-generating portion of heat-generating resistor provided between a pair of electrodes on the support. The arrangement pitch of the heat-generating resistor was 70 μm, and the uniformity of its dimension over the whole formation surface was examined to be good. Finally, on the electrothermal transducer was provided a SiO 2 layer as the protective layer and further the polyimide layer at the portion except for the heat-generating portion to complete the substrate for an ink jet head.
The substrate thus prepared was bonded to a covering member 5 made of glass having a recession for forming the liquid path 6 and the liquid chamber 10, etc. as shown in FIG. 1B to prepare an ink jet recording head, and a recording test therefor was performed. As the result, good recording could be practiced, with durability being also good.
EXAMPLE 2
A substrate for an ink jet head and an ink jet head using the substrate were prepared according to the present invention in the same manner as in Example 1 except for employing BCl 3 as the reactive gas for etching. Etching speed was 120 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 3
A substrate for an ink jet head and an ink jet head using the substrate were prepared according to the present invention in the same manner as in Example 1 except for employing BCl 3 +Cl 2 (flow rate ratio 1:1) as the reactive gas for etching. Etching speed was 260 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 4
A substrate for an ink jet head and an ink jet head using the substrate were prepared according to the present invention in the same manner as in Example 1 except for employing CF 4 as the reactive gas for etching. Etching speed was 31 ÅA/min
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 5
A substrate for an ink jet head and an ink jet head using the substrate were prepared according to the present invention in the same manner as in Example 1 except for employing C 2 F 6 as the reactive gas for etching. Etching speed was 32 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 6
A substrate for an ink jet head and an ink jet head using the substrate were prepared according to the present invention in the same manner as in Example 1 except for employing CHF 3 as the reactive gas for etching. Etching speed was 21 Å/min.
Also in this example, a substrate for ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 7
A substrate for an ink jet head and an ink jet head using the same were prepared according to the present invention in the same manner as in Example 1 except for employing ZrB 2 as the material for forming a heat-generating resistor. Etching speed was 320 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 8
A substrate for an ink jet head and an ink jet head using the same were prepared according to the present invention in the same manner as in Example 1 except for employing ZrB 2 as the material for forming a heat-generating resistor and employing CF 4 as the reactive gas for etching. Etching speed was 31 /min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 9
A substrate for an ink jet head and an ink jet head using the same were prepared according to the present invention in the same manner as in Example 1 except for employing TiB 4 as the material for forming a heat-generating resistor. Etching speed was 290 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
EXAMPLE 10
A substrate for an ink jet head and an ink jet head using the same were prepared according to the present invention in the same manner as in Example 1 except for employing TiB 4 as the material for forming a heat-generating resistor and employing CF 4 as the reactive gas for etching. Etching speed was 27 Å/min.
Also in this example, a substrate for an ink jet head and an ink jet head using the substrate were prepared with high precision and high quality.
In the present invention, the liquid path of the ink jet head may be formed by initially forming the wall-forming member of the liquid path with a photosensitive resin and then bonding the top plate to the wall-forming member.
In an ink jet head obtained according to the present invention, the direction of ink supply to the heat generating portion within the liquid path and the direction of ink discharge from the discharge opening may be substantially the same or different from each other (for example, forming generally a right angle).
Further, the ink jet head obtained according to the present invention may be of the so-called full line type having discharge openings arranged over the whole recording width of a recording medium.
FIG. 5 is a schematic perspective view showing the appearance of an ink jet device equipped with an ink jet head obtained according to the present invention. There are shown a main body 1000, a power switch 1100 and an operation panel 1200.
According to the method of the present invention, since the dry etching method which can control easily the state of etching is used for patterning of the heat-generating resistor layer, no registration working of the mask as in the prior art is required and there is no lowering in yield due to registration mistake of the mask.
Also, since etching of the heat-generating resistor layer is effected in the dry step, there is no generation of defective etching in the wet step as in the prior art.
Further, even with, for example, A4 size width (210 mm) silicon wafer, a substrate with excellent dimensional precision can be provided. | A method of preparing an ink jet head comprises a support, an electrothermal transducer formed on said support and having a heat-generating resistor and a pair of electrodes connected electrically to said heat-generating resistor, and a liquid path formed on said support corresponding to the heat-generating portion of said electrothermal transducer formed between said pair of electrodes, and communicating with a discharge opening for discharging liquid, which comprises the step of dry etching to pattern the material for said heat-generating resistor provided on said support in the form of a layer. | 1 |
This is a continuation of Ser. No. 608,241, filed Nov. 2, 1990, now abandoned.
BACKGROUND OF THE INVENTION
It is well known that address books, telephone books, daily dairies and other personal books in which information (in the form of names, addresses, telephone numbers, calendar dates and the like) is recorded for future reference often become cluttered and of reduced usefulness through the passage of time. This is typically due to the repeated need to amend entries, remove them, or to rearrange them, entailing messy erasures, strikeovers, white-outs, and similar awkward editorial endeavors.
The most common solution to the problem has been to simply replace these books on a regular basis requiring the time-consuming reentry of information from the old book to the new. Other solutions have included the use of selectively removable and rearrangeable pages (such as in loose-leaf notebooks). However, this system allows saving and/or rearranging of full pages of information rather than individual entries. Another solution has entailed the use of pages having multiple transparent pockets into which individual business cards or other information bearing elements may be inserted, removed and/or rearranged.
A new and improved personal information system for maintaining, on a semipermanent basis, the type of personal information described hereinabove, has been developed and is embodied in the notebooks described and claimed in Judith A. M. Baldwin U.S. Pat. No. 4,907,904, the details of which are herein incorporated by reference.
Specifically, the patented notebooks may be in bound or loose-leaf form, with the salient features being the association with and inclusion within the book of a supply of information carriers in the form of repositionable, pressure-sensitive adhesive coated labels, either blank or printed with information such as name, address and telephone number(s) or other calendar or reminder information, and special coated pages for readily removably mounting the pressure-sensitive adhesive labels.
The individual labels or information carriers, after being initially filled in with information, may be repalced or repositioned as desired in the appropriately indexed portion of the book.
The present invention is directed to an improved method of manufacturing two-sided label stock for use as pages in said notebooks in which pages have information carriers, within or without their matrices, on the front and obverse sides thereof, and which pages may be manufactured economically by available mass production techniques as in the manner to be described hereinafter. The improved construction of the two-sided label stock having removable, repositionable information carriers on both sides may be used in applications other than notebooks, for example the pages may be used to double the typical supply of pressure-sensitive labels ordinarily supplied in sheet or roll-form, with labels only on one side. They may be used to fill the applications gaps which exist in the ever-expanding repositionable label field due to the commercial availability of only one-sided label stock.
Accordingly, it is to providing a method of making new and improved two-sided repositionable label stock and the resulting label stock itself to which the present invention is directed.
SUMMARY OF THE PRESENT INVENTION
One sided repositionable label stock and/or repositionable pressure-sensitive adhesives used in their manufacture and in the manufacture of repositionable note paper are well known and are available in the commercial products of Avery International Corp., Pasadena, Calif. and Minnesota Mining and Manufacturing Co., St. Paul, Minn., among others. Indeed the prior art includes descriptions of note paper pads and dispensers for such pads which have repositionable pressure sensitive adhesives which are employed to advantage in the product of the new two-sided multi-repositionable label stock. These adhesives typically are infusible, inherently tacky, elastomeric microspheres prepared by an aqueous suspension polymerization process. Aqueous suspension polymerization processes are described, for example, in U.S. Pat. No. 3,691,140 to Silver; U.S. Pat. No. 4,166,152 to Baker et. al.; U.S. Pat. Nos. 4,495,318 and 4,598,212 to Howard; U.S. Pat. No. 4,786,696 to Bohnel; and U.S. Pat. Nos. 4,810,763 and 4,944,888 to Mallya et. al., each of which by reference is incorporated herein. The Mallya et. al. patent discloses inherently tacky infusible pressure-sensitive adhesive microspheres prepared by polymerizing at least one monomer which when polymerized will form a pressure-sensitive adhesive having a glass transition temperature less than about -20° C. in a medium in which the monomer is substantially insoluble and in the presence of a surfactant and a suspension stabilizer which are soluble in the organic medium and substantially insoluble in the monomer under conditions of shear sufficient to form suspended particles of a size less than 20 microns. The formed microspheres are transferred to a volatile organic medium and separated from the medium in which they were formed by a centrifugal separator at a force of at least 2,000 times the force of gravity. For brevity of description, these specific adhesives which are formulated to be reliably repositionable at least 7 times on calendered or supercalendered paper liner material or thermoplastic liner material or any other compatible liner material, are hereinafter referred to in abbreviated form as multi-repositionable pressure sensitive adhesive.
The new and improved method for manufacturing two-sided pages of information carriers, i.e. repositionable labels on the front and back surfaces thereof, within or without their matrices, generally includes the fundamental steps of:
(a) supplying a first roll of multi-repositionable pressure-sensitive adhesive transfer coated paper label stock laminated to a first silicone coated carrier sheet;
(b) providing a similar second roll of multi-repositionable pressure-sensitive transfer coated paper label stock laminated to a second silicone coated carrier sheet;
(c) supplying a roll of paper or plastic liner stock and directing said first and second rolls to delaminating stations;
(d) stripping said first and second carriers from said first and second rolls of label stock to expose said pressure-sensitive adhesive;
(e) directing webs of said first stripped label stock and said second stripped label stock to a laminating nip;
(f) laminating said first and second label stock to the front and rear faces respectively of said liner stock;
(g) forming individual removable, repositionable labels by die cutting techniques; and/or
(h) directing said laminated two-sided label stock into a finishing station where it may be continuously wound into rolls or sheeted.
For more complete understanding of the new and improved method of manufacturing pages of multi-repositionable pressure-sensitive information carriers on the front and rear surfaces thereof, and for a better appreciation of the advantages to be derived from the new methods and the resultant improved products, reference should be made to the following detailed description of the invention, taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the method and apparatus for carrying out the methods of the present invention;
FIG. 2 is front elevational view of a new and improved notebook page embodying the present invention;
FIG. 3 is front elevational view of the new page with the information carriers removed leaving a matrix having defined zones for attachment of multi-repositionable pressure-sensitive information carriers;
FIG. 4 is a front elevational view of the new page of information carriers with the matrix removed; and
FIG. 5 is a cross sectional view of the page of FIG. 2. taken along line 5-5 thereof.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2, a new and improved notebook page having repositionable pressure-sensitive adhesive-coated information carries on both the front and rear sides thereof is indicated generally by reference numeral 10. In the illustrated page format both the front and rear sides have five information carriers 11 carried on a linear sheet 12, as shown in FIG. 5. In accordance with the principles of the aforementioned U.S. Pat. No. 4,907,904, each of the information carriers is pre-printed with typical diary information such as name, address, telephone and fax numbers, although other information may be substituted therefor as will be appreciated. In the embodiment of FIG. 2 the information carriers 11 are surrounded by a matrix sheet 13, which matrix 13 has printed repositioning zone indicators 14, which aid the user in repositioning labels properly when they are moved from one position to another in a notebook or diary. Advantageously, the notebook pages are formed having rounded corners 15 and an elongated binder slot 16 for use in looseleaf diary. Individual labels 11 are separable from the matrix 13 by die cuts 17, which circumscribe each of the labels 11, as should be understood. The particular format of the notebook page of FIG. 2, for certain applications such as those illustrated in the U.S. Pat. No. 4,907,904, requires that the matrix 13 be stripped from the carrier 12 to provide individual pages in which only the repositionable pressure-sensitive adhesive information carriers 11 are present. An illustration of such a page is shown in FIG. 4 with that page being indicated generally by reference numeral 20. But for the removal of the matrix 13 from the front and rear surfaces of the liner 12, the notebook page 20 is in all respects identical to the notebook page 10. An important aspect of the production of the notebook pages 10 or 20, as well as the two-sided label stock from which those pages are produced is the usage of a multi-positionable pressure-sensitive adhesive 21 (FIG. 5), which adheres the individual labels 11 to the liner 12.
Referring now to FIG. 1, the two-sided label stock of the present invention may be readily manufactured by mass production techniques as follows. A supply 30 of multi-repositionable pressure-sensitive adhesive coated label stock 32 (comprised of adhesive-coated paper 34 and carrier 33), in which the pressure-sensitive adhesive has been transfer-coated to a silicone release liner or the like is directed around guide roll 36 to a delaminating station 31 where the silicone-coated carrier sheet portion 33 is separated from the paper label stock carrying the transfer-coated multi-positionable pressure-sensitive adhesive 21 (FIG. 5), which pressure-sensitive transfer-coated paper web 34 is directed to first laminating station 40, where it is laminated to a web of liner material 51, which is supplied from a roll 50. The liner material 51 may be calendered or supercalendered paper stock of approximately 54 to 60 pounds weight for notebook pages or it may be a suitable thermoplastic web or any other material which provides inherent release properties to the multi-positionable pressure-sensitive adhesive employed herein. Of course, heavier or lighter liner material may be used for particular applications. At this stage, the liner 51 with the pressure-sensitive repositionable adhesive-coated paper 34 laminated to one surface thereof, is directed through a series of repositioning or rollers 60, 61, 62, where it is then directed to a second laminating nip 70.
A second supply 80 of repositionable pressure-sensitive transfer adhesive-coated paper label stock 80 is directed to a second delaminating nip 81 where the silicone coated carrier 83 is removed from the pressure-sensitive adhesive-coated paper label stock 82, in a manner similar to that described with the first roll 30. The delaminated carriers 83 and 33 are wound into rolls 85 and 35, respectively, and subsequently discarded.
The web of pressure-sensitive adhesive coated label stock 84 is then directed around guide roll 87 to laminating nip 70 where it is joined with the partial laminate comprised of the paper liner 51 or the plastic liner 51 to which label stock 34 had been previously adhered. The coated web 84 is then joined to the liner 51 to form two-sided label stock 86 comprised of liner 51 and label stock 84 on one surface and label stock 34 on the other surface.
The new and improved two-sided label stock 86 is then directed to a die cutting station 90 where opposed rotary die cutting rolls 91, 92 engage the upper/lower surfaces of the web 86 to form individual labels 11, each of which is circumscribed by die cut 17 in the particular label shape which is desired. Thereafter, the stock 86 is directed to a printing station 100 where inked printing rolls 101 and 102 apply the requisite information to the carriers and/or otherwise tint or color the sheets 84, 34 which are now in the form of matrices 13 (FIGS. 2, 3 and 5) by virtue of having passed through the die cutting station 90.
The two-sided label stock 86 after it is printed and die cut is directed to a sheeting station 110, where the web 86 is cut by rotary cutters 111, 112 into its finished sizes and shapes, such as shown in FIG. 2, where the individual pages have rounded corners and elongated binder slots. The individual sheets 10 are then stacked and assembled into packages for use in notebooks of the type describe more completely in the aforementioned Baldwin U.S. Pat. No. 4,907,904.
While the steps of delaminating the supplied rolls 30 and 80 of multi-positionable pressure-sensitive transfer adhesive-coated label stock and joining the delaminated webs 34, 84 in a sandwiched relation to a liner web 51 are shown in a particular sequence, along with a sequence of printing, die cutting, and sheeting, it is to be understood that the particular steps may be combined or carried out in other sequences as may be found desirable or necessary in a particular application. Likewise, the particular liner sheet 51 which is described hereinabove as being a plastic or a paper which has been calendered or supercalendered and is of a weight of approximately 54 to 60 pounds per ream, (the thickness of the liner being advantageously approximately 2 to 3 millimeters) may be any sheet material having appropriate release properties. Similarly, the multi-repositionable adhesive described hereinabove may be any one of those described in the aforementioned patents (or otherwise chosen so that the adhesive is compatible and readily releasable from the liner sheet 51 and repositionable with respect thereto at least 7 times).
It should be understood that the specific embodiment of the new and improved methods of manufacturing sheet stock having multi-repositionable information carriers on front and rear faces thereof have been illustrated and described herein for the purposes of example only, and that it will be further understood that certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention. | A notebook page with repositionable labels on both sides thereof. Each side of the page is covered with a web of pressure-sensitive label stock which is kiss die cut to form removable, repositionable labels within permanent matrices. The matrices define zones which facilitate repositioning of the removed labels. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a vacuum cleaner.
[0003] 2. Related Background Art
[0004] Vacuum cleaners conventionally comprise a permeable dust bag, which filters and retains the dirt and dust drawn into the vacuum cleaner by the induced air flow. Nowadays, it has become popular to provide vacuum cleaners, in which the separated dirt and dust is collected in a rigid dirt receptacle that can be emptied and re-used. Such so-called bagless cleaners alleviate the need to purchase and replace the dust bags. However, a disadvantage of re-usable dirt receptacles is that the receptacles are often dirty to handle and clouds of dirt and dust can be emitted into the atmosphere when the receptacles are emptied, with the obvious health risks and resultant contamination of the vacuum cleaner and the user's environment with a layer of dust.
[0005] Many bagless vacuum cleaners nowadays comprise a cyclonic separator, which deposits the separated dirt and dust in a rigid dirt receptacle. Cyclonic vacuum cleaners offer the advantage over bag-type cleaners of maintaining a more constant level of suction performance regardless of the quantity of dirt present in their dirt receptacle.
[0006] One of the main disadvantages of known cyclonic vacuum cleaners is that the procedure for emptying their dirt receptacles is a potentially dirty and unhygienic process. Instead of simply removing a closed paper bag full of dirt from the vacuum cleaner, and dropping it into a dustbin, emptying a cyclonic cleaner usually involves tipping a mass of loose dust and dirt out of its dirt receptacle, following removal of the receptacle from the cleaner. This emptying process can involve knocking and/or shaking the dirt receptacle to dislodge agglomerated dust and any masses of fibrous material, such as fluff and hairs that may be present.
[0007] This problem is exacerbated because fine dirt typically collects at the base of the dirt receptacle, with coarse and fibrous dirt lodging in the upper region of the receptacle. When the dirt receptacle is inverted for emptying, the entire mass of dirt falls in an uncontrolled manner into the vessel used for its final disposal, typically a dustbin or refuse bag. This uncontrolled discharge usually results in the lighter dirt fractions being disturbed by the movement of the heavier fractions, whereupon the clothing and anatomy of the vacuum cleaner user may become contaminated with dust. The attendant escape of dust into the user's home environment is equally undesirable.
[0008] Many popular cyclonic vacuum cleaners have a simple cylindrical dirt receptacle, usually of transparent plastic material, which is removed from the cleaner and inverted over the dustbin for emptying. More recent cleaners have had a pivoted flap at the bottom of their dirt receptacle, this being released by some form of manually-operated latch to swing open for emptying under gravity or, in some cases, being spring-loaded to aid opening. In either case, dust and fibres suddenly fall out of the dirt receptacle when the flap opens. This flap-type emptying system exacerbates the problem of contamination, since the fine dust falls out of the bottom of the receptacle closely followed by the coarse and fibrous dirt, which falls through and/or lands on top of the fine dust causing clouds of fine dust to become airborne and contaminate the environment during the emptying process.
[0009] Thus, there is the need to provide a dirt receptacle for a cyclonic vacuum cleaner which is clean to use and does not generate clouds of dirt and dust when emptied.
[0010] EP 1 199 023 attempts to solve the above-mentioned problems by providing a cyclonic separator for a vacuum cleaner in which the lower region of the cylindrical dirt receptacle is separated from the upper region by a perforated disc-shaped partition. In use, the fine dust and dirt particles fall through the perforations in the disc and are retained in the region below the disc. The coarser particulate and fibrous material are retained above the disc. During emptying, the lower region of the dirt receptacle can be opened and carefully emptied into a suitable waste receptacle for disposal. Having emptied the fine dust, the entire dirt receptacle containing the coarse and fibrous material, may then be inverted over the waste receptacle to complete the emptying process.
[0011] Although the dirt receptacle emptying arrangement disclosed in EP 1 199 023 constitutes a considerable improvement over the emptying arrangements of most commercially available cyclonic cleaners, the receptacle is complicated and expensive in construction and is difficult to use.
[0012] We have now devised a vacuum cleaner which alleviates the above-mentioned problems.
SUMMARY OF THE INVENTION
[0013] In accordance with this invention, there is provided a dirt receptacle for a vacuum cleaner, the receptacle comprising a rigid container having an outlet for the emptying of collected dirt, a closure for closing the outlet, and an actuator for moving the closure between a closed position and an open position, said actuator being operable to control the position of the closure between said open and closed positions.
[0014] In use, the receptacle is emptied by initially moving the closure to a partially opened position, in which fine dirt and dust can be emptied through the restricted outlet in a controlled manner. The restricted size of the outlet retains any coarser and fibrous dirt inside the receptacle. Once the fine dirt has been emptied, the closure can be moved to its fully open position to allow the coarse dirt and fibrous matter to be emptied from the receptacle.
[0015] The present invention thus provides a clean and hygienic way of empting the receptacle by allowing the fine and coarse dirt to be emptied in two distinct operating stages, thereby avoiding the problem of dust contamination when all of the dirt is released in an uncontrolled single stage.
[0016] The restricted size of the opening also allows a more controlled release of the fine dirt and avoids the problem of dust contamination caused by a sudden release of the dirt.
[0017] The receptacle is simple and inexpensive in construction and is straightforward to use.
[0018] Preferably, the closure locates at said partially opened position, in order to provide a tactile indication to the user that the closure is in the correct position for the emptying of fine dust.
[0019] Preferably, the outlet is provided at a position on the container which is located at the bottom thereof when the container is in use, such that the outlet is positioned directly adjacent the fine dirt which collects at the bottom of the container.
[0020] Preferably means are provided for retaining the closure in said open and/or closed positions.
[0021] Preferably the closure is biassed into said fully open position.
[0022] Preferably, the container comprises an open bottom forming the outlet.
[0023] Preferably, the closure comprises a flap pivoted to the container.
[0024] Preferably the actuator comprises a handle mounted directly to said flap, preferably adjacent the point where the flap is pivoted to the container.
[0025] Preferably the flap is also mounted to the container for translatory movement towards and away from said outlet thereof.
[0026] Preferably means are provided to guide the translatory movement of said flap towards and away from said outlet.
[0027] Preferably said guide means is arranged to only permit pivotal movement of the flap, when the latter is in a partially opened position between said open and closed positions.
[0028] Preferably, the guide means is arranged to hold said flap in its fully opened position.
[0029] Also, in accordance with this invention, there is provided a vacuum cleaner comprising a dirt receptacle as hereinbefore described.
[0030] Preferably the vacuum cleaner comprises a cyclonic separator having a cylindrical-walled separation chamber.
[0031] Also, in accordance with this invention, there is provided a method of emptying a dirt receptacle of a vacuum cleaner, the receptacle comprising a rigid container having an outlet for the emptying of collected dirt, a closure for closing the outlet, the closure being moveable between a normally closed position and an open position, the method comprising removing the dirt receptacle from the vacuum cleaner, partially opening the closure and empting fine dirt from the receptacle through the restricted outlet prior to fully opening the closure and empting the remaining dirt from the receptacle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Embodiments of this invention will now be described by way of examples only and with reference to the accompanying drawings, in which:
[0033] FIG. 1 is a schematic view of a vacuum cleaner in accordance with this invention;
[0034] FIG. 2 is a perspective view of a dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its closed state;
[0035] FIG. 3 is a side view of the dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its closed state;
[0036] FIG. 4 is a perspective view of a dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its partially opened state;
[0037] FIG. 5 is a side view of the dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its partially opened state;
[0038] FIG. 6 is a perspective view of a dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its fully opened state;
[0039] FIG. 7 is a side view of the dirt collection bin of the cleaner of FIG. 1 , showing the discharge flap thereof in its fully opened state;
[0040] FIG. 8 is a perspective view of a dirt collection bin of an alternative embodiment of vacuum cleaner in accordance with this invention, showing the discharge flap thereof in its closed state;
[0041] FIG. 9 is a perspective view of the dirt collection bin of FIG. 8 , showing the discharge flap thereof in its fully opened state;
[0042] FIG. 10 is a perspective view of a portion of a dirt collection bin of a preferred embodiment of vacuum cleaner in accordance with this invention, showing the discharge flap thereof in its closed state;
[0043] FIG. 11 is a perspective view of a portion of the dirt collection bin of FIG. 10 , showing the discharge flap thereof in its partially opened state;
[0044] FIG. 12 is a perspective view of a portion of the dirt collection bin of FIG. 10 , showing the discharge flap thereof in its fully opened state; and
[0045] FIG. 13 is a longitudinal sectional view through a portion of the dirt collection bin of FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] Referring to FIG. 1 of the drawings, there is shown an upright vacuum cleaner comprising a wheeled suction head 10 , to which a body portion 11 is pivoted for movement between an upright position and an inclined operative position. A motor and fan are mounted in a bottom portion 12 of the body 11 of the cleaner.
[0047] A separation unit 13 mounted in the body 11 of the cleaner comprises a cyclone separator and a filter. In use, the fan induces an airflow through the cleaner from the suction head 10 through the separation unit 13 , where dirt and dust separated from the airflow by the cyclone is collected in a removable dirt collection bin 14 mounted directly below the separation unit 13 . The cyclone separator comprises a cylindrical wall and for practical purposes, the side wall of the collection bin 14 is a downward extension of the wall of the cyclone.
[0048] The cyclonic separation action causes the finer dirt particles F to collect at the bottom of the collection bin 14 below the coarser dirt particles and fibrous matter C.
[0049] Referring to FIGS. 2 and 3 of the drawings, the collection bin 14 comprises a cylindrical side wall 15 having an open top which communicates with the cyclone separator. The bottom of the bin 14 is closed by a flap 16 which is pivoted by a shaft to the side wall 15 of the bin 14 for rotation about an axis which extends perpendicular to the longitudinal axis of the bin. A torsion spring 17 biases the flap 16 downwardly into a position where the bottom of the bin 14 is fully open.
[0050] The flap 16 comprises a pair of spaced-apart formations 18 , between which the above-mentioned shaft extends. Each formation 18 comprises an outwardly facing abutment surface which lies in a plane that extends parallel to both the longitudinal axis of the bin and rotational axis of the flap 16 , when the later is in its fully closed position.
[0051] An actuator 19 is slidably mounted to the outer surface of the side wall 15 of the bin 14 for movement in a direction which extends parallel to the longitudinal axis of the bin. The actuator 19 comprises a pair of arms having lower ends which abut the respective flap formations 18 .
[0052] A foldable handle 20 is attached to the arms of the actuator 19 for sliding the actuator 19 in the upward and downward directions shown in the drawings. In its fully downward position, the bottom ends of the arms of the actuator 19 bear against the abutment surface of the flap formations 18 , thereby holding the flap in its closed position and preventing the collected dirt and dust from falling out of the bottom of the bin 14 whilst the cleaner is in use and whilst the bin 14 is being carried to a waste receptacle for emptying. The handle 20 also serves as a handle for supporting the bin 14 whilst it is being carried.
[0053] Referring to FIGS. 4 and 5 of the drawings, in order to empty the bin 14 , the user slides the actuator 19 upwardly using the handle 20 , thereby allowing the flap 16 to open under the spring bias, until the bottom ends of the arms of the actuator 19 engage in respective detents 21 formed in the abutment surfaces of the flap formations 18 . In this position, the flap 16 is retained in the partially open position and the fine dirt and dust F at the bottom of the bin 14 can be emptied through the small opening at the bottom of the bin 14 . Any coarse dirt and fibrous matter C cannot pass through the opening and is retained inside the bin 14 .
[0054] Referring to FIGS. 6 and 7 of the drawings, in order to fully empty the bin 14 , the user has to slide the actuator 19 more upwardly using handle 20 , thereby allowing the flap 16 to fully open under the applied spring bias. In this position, all of the remaining dirt and dust inside the bin 14 is free to fall through the open bottom of the bin 14 .
[0055] Following emptying of the bin 14 , the actuator 19 is returned to its lower position using the handle 20 , thereby closing the flap 16 against the spring bias. The body 11 of the cleaner is preferably adapted such that the bin 14 cannot be mounted to the cleaner until the actuator 19 has been returned to the lower position, thereby avoiding the risk of the flap 16 opening whilst the bin 14 is removed from the cleaner.
[0056] The upper surface of the flap 16 is contaminated with dirt and dust. However, it will be appreciated that actuator 19 enables the user to open and close the flap 16 without having to touch the flap itself.
[0057] Referring to FIGS. 8 and 9 of the drawings, there is shown an alternative embodiment of a bin 14 , which is similar to the above-mentioned bin and like parts are given like reference numerals. In this embodiment, a pair of pinions 42 are mounted to the flap 16 for rotation about the rotational axis of the flap 16 . A handle 40 is pivotally mounted to the external surface of the wall 15 of the bin 14 for rotation about an axis which extends parallel to the axis of flap rotation. A second pair of pinions 41 are mounted to the handle 40 and are engaged with respective ones of the flap pinions 42 .
[0058] In order to open the flap 16 , the handle 40 is rotated about its rotational axis, causing the pinions 41 to correspondingly turn the flap pinions 42 . A detent (not shown) is provided to retain the flap 16 in its partially opened position and to provide a tactile indication to the user that the flap 16 is in the correct position for the emptying of fine dirt.
[0059] Referring to FIGS. 10 to 13 of the drawings, there is shown a preferred embodiment of a bin 14 , which is similar to the above-mentioned bins and like parts are given like reference numerals. The flap 16 is pivotally mounted between a pair of parallel spaced apart flanges 52 provided on the lower end of the rear of the side wall 15 of the bin 14 . The flanges 52 extend parallel to each other and axially of the bin. Each flange 52 comprises an upper slot 53 which extends axially of the bin and a lower unshaped slot 54 having long and short arms 54 a , 54 b extending axially of the bin.
[0060] The flap 16 comprises a portion 56 which extends between the flanges 52 . A pair of upper projections 55 extend outwardly from opposite sides of the flap extension 56 into the respective upper slots 53 of the flanges 52 . A pair of lower projections 57 also extend outwardly from opposite sides of the flap extension 56 into the respective lower slots 54 of the flanges 52 .
[0061] A handle 58 extends over the outer surface of the flap extension 56 . The lower edge of the handle 58 is spaced away from the outer surface of the flap extension 56 , so that a user can grasp the handle 58 in the palm of their hand, with their fingers extending around the lower edge of the handle. A concealed spring 59 , connected between the flap extension 56 and the exterior of the wall 15 of the bin 14 , biasses the flap 16 upwardly. A seal 59 extends around the flap 16 to seal against the bottom edge of the wall 15 of the bin 14 .
[0062] In use, when the bin 14 is stowed on the body 11 of the vacuum cleaner, the flap 16 is in the closed position of FIG. 10 . The spring 59 serves to retain the flap 16 in the closed position, so that no dirt and dust can escape. The handle 58 is preferably concealed behind the bin 14 when the latter is stowed on the body 11 of the vacuum cleaner.
[0063] In order to empty the bin 14 , the user removes the bin 14 from the body 11 of the cleaner. The user then pushes the handle 58 downwardly, thereby allowing the flap 16 to open under the spring bias, until the projections 55 , 57 on the flap extension 56 reach the lowermost point of their respective slots 53 , 54 . It will be appreciated that the attitude of the flap 16 remains constant as the handle is pushed downwardly as hereinbefore described.
[0064] In this position, as shown in FIG. 11 , the flap 16 can be retained in the partially open position by maintaining a downward bias on the handle 58 . Fine dirt and dust at the bottom of the bin 14 can be emptied through the small opening at the bottom of the bin 14 . Any coarse dirt and fibrous matter cannot pass through the opening and is retained inside the bin 14 .
[0065] In order to fully empty the bin 14 , the user has to pull the lower edge of the handle 58 away from the bin 14 , causing the lower projections 57 to slide along the bottom of their respective unshaped slots 54 , allowing the flap 16 to pivot further open about an axis extending through the upper projections 55 . The downwards force on the handle 58 is then released, thereby causing the lower projections 57 to move a short distance up the short arms 54 b of the lower slots 54 . The spring 59 serves to retain the flap 16 in this fully open position, as shown in FIG. 11 , in which all of the remaining dirt and dust inside the bin 14 is free to fall through the open bottom of the bin 14 .
[0066] Following emptying of the bin 14 , the handle 58 is pushed downwardly and then inwardly, thereby allowing the flap to close under the applied spring bias. The body 11 of the cleaner is preferably adapted such that the bin 14 cannot be mounted to the cleaner until the flap 16 has been closed, thereby avoiding the risk of dirt and dust escaping from the bin when in use.
[0067] A bin in accordance with the present invention is simple and inexpensive in construction, yet allows a staged discharge of fine and coarse dirt, thereby minimising the risks of dust contamination during emptying.
[0068] Whilst an upright vacuum cleaner has been shown and described in the drawings, it will be appreciated that the present invention is equally applicable to a canister or other type of vacuum cleaner.
[0069] Reference is made to our co-pending US applications claiming priority from United Kingdom Patent Application Nos. 0307929.0 and 0307930.8 of 5 Apr. 2003, the disclosures of which are incorporated herein by reference.
[0070] While the preferred embodiments of the invention have been shown and described, it will be understood by those skilled in the art that changes or modifications may be made thereto without departing from the true spirit and scope of the invention. | A vacuum cleaner comprises a rigid dirt receptacle 14 having an outlet at one end, through which the collected dirt and dust can be emptied, a flap 16 for closing the outlet, and an actuator 58 for moving the flap 16 between a closed position and an open position, the actuator 58 being operable to control the position of the flap 16 between the open and closed positions.
A location is provided at a partially opened position of the flap 16 , at which position fine dirt and dust can be emptied through the restricted outlet in a controlled manner. The restricted size of the outlet retains any coarse and fibrous dirt inside the receptacle 14 . Once the fine dirt has been emptied, the flap 16 can be moved to its fully open position to allow the coarse dirt and fibrous matter to be emptied from the receptacle 14 separately from the fine dust. | 0 |
BACKGROUND OF THE INVENTION
This invention relates in general to the production of bagged ice, and more particularly to equipment for storing ice cubes prior to bagging.
On a commercial basis ice is produced in relatively large quantities by bulk ice machines. These machines, however, have no capacity for storing the ice or bagging it, and consequently additional equipment is necessary in the form of bulk ice bins and bagging machines. The ice bins of course store the ice derived from the bulk ice making machine and allow it to be withdrawn slowly for bagging in the bagging machine.
Most ice bins for small and medium size commercial ice plants are nothing more than adaptations of farm equipment. For example, some are derived from the beds of farm wagons, others are essentially spreaders for fertilizer, while still others are mere corn cribs. Irrespective of their derivation, conventional ice bins are quite expensive and add significantly to the capitalization required for an ice plant. Moreover, many are open on top and not insulated, and therefore they are not well suited for warm room bagging.
Aside from the foregoing, the capacity of a bulk ice machine to a large measure depends on the temperature of the water that is fed to the machine. To increase the capacity of their machines, many operators of small and medium size ice plants have installed precooling units in the water line leading to their machines. These precoolers are separate refrigeration systems and are expensive in their own right. They consequently add still more to the capital required for the plants in which they are used and furthermore are expensive to operate.
SUMMARY OF THE INVENTION
One of the principal objects of the present invention is to provide a bulk ice storage bin capable of storing ice cubes produced by a bulk ice making machine so that the ice can be subsequently bagged under warm room bagging conditions. Another object is to provide a machine of the type stated which is well insulated and closed at its top for storing ice for an extended time prior to bagging. A further object is to provide a bulk ice bin of the type stated that is configured to accommodate the transfer of ice from the bulk ice machine. An additional object is to provide an ice bin of the type stated which precools the water for the bulk ice machine so as to increase the capacity of the machine. Still another object is to provide an ice bin of the type stated that is inexpensive to manufacture. These and other objects and advantages will become apparent hereinafter.
The present invention is embodied in an apparatus including a housing having walls that enclose a space in which ice cubes are stored. One of the walls is inclined to accommodate a conveyor which discharges ice cubes through an opening in the inclined wall and into the enclosed space. One of the walls has an opening near the bottom of the enclosed space for withdrawing cubes from the bin and one of the walls also has an opening near the top of the enclosed space for gaining access to the space. The invention also resides in the combination of an ice making machine, a storage bin, a conveyor for delivering ice from the machine to the bin, and a water line that supplies water to the machine. The water line passes through the interior of the bin to precool the water before it is delivered to the ice making machine. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form part of the specification and wherein like numerals and letters refer to like parts wherever they occur-
FIG. 1 is a perspective view showing the left side and front of a bulk ice bin of the present invention as well as the ice machine and conveyor which are used in conjunction with that bin;
FIG. 2 is a perspective view showing the left side and rear of the ice bin as well as the conveyor and the ice making machine;
FIG. 3 is a front elevational view of the ice bin taken along line 3--3 of FIG. 1;
FIG. 4 is a sectional view of the ice bin taken along line 4--4 of FIG. 1; and
FIG. 5 is a sectional view of the ice bin taken along line 5--5 of FIG. 2.
DETAILED DESCRIPTION
Referring now to the drawings, a bulk ice bin A (FIGS. 1 and 2) stores ice that is produced in cube form by a bulk ice machine B. The bin A and ice machine B are separate from each other, but are connected by auger-type conveyor C which delivers the ice cubes that are produced in the machine B to the bin A where they are stored for subsequent bagging. The bagging may be accomplished by manually removing the cubes from the bin, and placing them in bags, but the preferred procedure is to place a bagging machine D at the withdrawal door of the ice bin and allow the bagging machine D to fill the bags with a properly metered quality of ice cubes. The bin A is insulated and completely encloses the space in which the ice cubes are stored. It is thus well suited for warm room ice bagging.
The bulk ice bin A rests upon a foundation 2 and includes a housing 4 and supporting legs 6 which extend from the housing 4 to the foundation 2 for supporting the housing 4 in an upright position upon the foundation 2. The housing 4 in turn has lower and upper sections 8 and 10, respectively. The lower section 8 holds the large bulk of the ice cubes and is where the ice cubes are withdrawn. The legs 6 are furthermore secured to and project from the lower section 8. The upper section 10, on the other hand, closes the lower section 8 and accommodates the conveyor C which delivers the ice cubes to the bin A, the upper section having the entry at which the cubes are introduced into the bin A.
More specifically, the lower section 8 of the housing 4 possesses a generally rectangular configuration, it being composed of a front wall 16, a back wall 18, side walls 20 and 22, and a bottom wall 24, all of which are made of metal and are joined together along the margins, preferably by welds, to form water-tight joints. The two side walls 20 and 22 have vertical upper portions and inclined lower portions the latter of which converge towards and are joined to the bottom wall 24 which is inclined downwardly from the back wall 18. The vertical back wall 18 is joined at its sides to the vertical upper portions of the two side walls 20 and 22, whereas the inclined bottom wall 24 is joined along its sides to the lower portions of the side walls 20 and 22. The front wall 16, on the other hand, is vertical and planar throughout, and is joined along its side margins to the side margins of the two side walls 20 and 22 and along its bottom margin to the bottom wall 24. Owing to the inclination of the side walls 20 and 22, the side margins of the front wall 16 taper downwardly and converge toward the bottom wall 24. Adjacent to the bottom wall 24 where the lower margin of the front wall 16 is horizontal, the front wall 16 is provided with a rectangular opening 26 and tracks 28 (FIG. 3) along the sides of the opening 26, and these tracks receive the side edges of a door 30 such that the door 30 can slide upwardly and downwardly on them. Indeed, the tracks 28 extend the full height of the front wall 16 to enable the door 30, which is large enough to completely cover the opening 26, to slide upwardly to a position in which the opening 26 is entirely unobstructed. The tracks 28 also have a handle 32 connected to them such that it pivots across the front of the door 30, and this handle is connected to the door 30 by links 34 so that when the handle 32 is elevated, the door 30 rises.
The legs 6 that support the housing 4 on the foundation 2 are welded to the inclined portions of the side walls 18, 20 and to the bottom wall 24 and in effect cradle the lower portion 8 of the housing 4, presenting the opening 26 of the front wall 16 low enough to align with the collecting hopper of the bagging machine D. The lower section 8 may be constructed from the bed of a conventional farm wagon, but its steel walls 16, 18, 20 and 24 should be covered on their outwardly presented surfaces with a suitable heat insulating material such as 11/2" cellular polystyrene slab material.
The upper section 10 of the housing 4 rests on the lower section 8 and completely encloses the upper end of the lower section 8. It includes a front wall 36, a rear wall 38, side walls 40 and 42, and a top wall 44, all of which is joined together to form a closure for the upper end of the lower section 8. The front wall 36, like the front wall 16 of the lower section is vertical, and indeed forms a continuation of the front wall 16 on the lower section. The front wall 36 also contains an opening 46 which is located directly above the opening 26 in the lower section 8. The opening 46 is normally closed by a door 48 that is supported on hinges so that it can be opened to provide access to the interior of the housing 4. The two side walls 40 and 42 are likewise in a vertical disposition and form upward continuations of the vertical upper portions for the side walls 20 and 22, respectively, on the lower section 8. The back wall 38, along its lower margins align with the back wall 18 of the lower section 8, but instead of being vertical, it is inclined forwardly toward the top wall 44. As a result the two side walls 20 and 22 have a trapezoidal configuration while the top wall 44 is considerably smaller than the upper end of the lower section 8. The front wall 36, the two side walls 40 and 42, and the back wall 38, may be constructed muck like conventional building walls with 2×4 studs and plates, plywood sheathing, and bat-type insulation between the studs.
The inclination of the back wall 38 for the upper section 10 corresponds generally to the inclination of the conveyor C leading from bulk ice making machine B. Centered in the inclined back wall 38 near the upper end of it is an opening 50 (FIG. 2) into which the ice cubes are discharged by the conveyor C. In this regard, the auger of the conveyor C is generally enclosed, as is the upper end of the conveyor C, all to maintain the ice cubes within the auger flight and insulate the cubes as much as possible from the surrounding atmosphere. The upper end of the conveyor C projects into the opening 50 and forms a good seal with it.
The walls 16, 18, 20, 22 and 24 of the lower section 8 and the walls 36, 38, 40, 42 and 44 of the upper section form a space 52 that is entirely enclosed. The conveyor C introduces ice cubes into the space 52 through the opening 50 in the inclined back wall 38, whereas ice cubes are withdrawn from the enclosed space through the opening 26 in the lower front wall 16. The opening 46 in the upper front wall 36 provides access to the enclosed space 52.
Within the confines of the vertical portions of the back and side walls 18, 20 and 22 for the lower section 8 of the housing 4 is a distribution auger 56 (FIGS. 4 and 5) which is rotated by a gear motor 58 mounted on the side wall 20. The auger 56 extends between the side walls 20 and 22 and is parallel to the front and back walls 16 and 18. It spirals such that ice cubes which are caught within its flights are conveyed toward the side walls 20 and 22. In other words, the auger 56 has a left hand spiral on one side of its midpoint and a right hand spiral on the other side. As the ice cubes are deposited within the enclosed space 52 of the housing 4, they have a tendency to "cone", that is form a peak in the center of the housing 4. The auger 56, by driving the ice cubes toward the side walls 20 and 22 distributes the ice cubes more uniformly within the housing 4, thus enabling the housing 4 to hold a greater quantity of cubes. While the auger 56 in effect increases the capacity of the housing 4, it is not absolutely essential for the operation of the ice bin A.
The side wall 40 for the upper section 10 of the housing supports an evaporator unit 64 (FIG. 4) that is located entirely within the interior of the housing 4 and forms part of a refrigeration system. The evaporator unit 64 includes a coil 66 and a fan 68 located above the coil 66, the latter being adapted to draw air across the coil 66 and thereby cool the air. The fan 68 discharges the air along the underside of the top wall 44. In addition to the evaporator unit 64, the refrigeration system includes a thermostat 70 (FIG. 3) which senses the temperature of the air within the enclosed space 52 and causes the refrigeration system to energize so as to maintain the interior of the housing 4 at a predetermined temperature, preferably about 40° F.
Connected with the ice making machine B is a water line 74 that supplies the water from which the ice cubes are made. The water line passes into and out of the housing 4 and within the lower portion of the enclosed space 52 it assumes the configuration of a coil 76 (FIG. 5). Thus the coil 76 is practically always immersed in ice and as a consequence the water within it is cooled so that the water fed into the ice making machine B is at a lower temperature than would otherwise be the case.
Along the front of the housing 4 is an elevated platform 80 (FIG. 1) and stairs 82 which lead up to the platform 80, yet are offset to the side of the opening 46. The platform 80 is located above the opening 26, but below the opening 46. It thus provides convenient access to the the opening 46 and its door 48 without obscuring the opening 26. Consequently, the bagging machine D is easily placed in front of the opening 26 for accepting ice cubes that tumble from it.
OPERATION
In use, the bulk ice bin A stores ice cubes that are produced in the bulk ice machine B. More specifically, the machine B converts precooled water which is derived from the water supply line 74 into ice cubes which are deposited at the lower end of the conveyor C. By means of its auger, the conveyor C elevates the ice cubes over the inclined back wall 38 of the upper section 10 for the housing 4 and discharges them through the opening 50 in the back wall 18. The ice cubes drop downwardly and accumulate within the enclosed space 52, building up in a peaked configuration on the bottom wall 24 as well as on the inclined portions of the side walls 20 and 22. If enough ice is allowed to accumulate, its peak will eventually reach the distributing auger 56 which extends between the two side walls 20 and 22 of the lower section 8 for the housing 4. The ice at the top of the accumulation is caught within the auger flights and driven toward the side walls 20 and 22 and this of course tends to level the ice cubes within the space 52 so that they assume a more uniform distribution.
To withdraw ice cubes from the housing 4, the handle 32 is merely lifted and this of course causes the door 30 to slide upwardly on its tracks 28. As a consequence, the ice cubes tumble out of the opening 26. By placing the hopper of a bagging machine D below the opening, the ice is delivered to the bagging machine which meters it and deposits it within suitable bags. Sometimes the ice tends to bridge within the enclosed space 52 of the housing 4, meaning that the ice cubes jam together into a relatively solid mass which remains intact after the ice beneath it is withdrawn through the opening 26. This mass or "bridge" is easily broken into separate ice cubes merely by opening the door 48 in the upper portion of the housing 4 and striking the mass a few times with a blunt instrument. The ice cubes thereupon drop to the bottom of the space 52 where they can be withdrawn through the opening 26 for bagging.
The refrigeration system operating through the evaporator unit 64 maintains the enclosed space 52 at a temperature which preserves the ice for a substantial period of time, at least long enough for convenient warm room packing. A suitable temperature is 40° F.
Since the water that is used by the ice machine B passes through the coil 76 that is immersed within the ice cubes in the housing 4, that water is cooled to about 40° before it enters the ice making machine B. This improves the capacity of the ice making machine significantly. Even though the heat extracted from the water that passes through the housing melts some of the ice within the housing 4, a significant net gain is achieved. For example, precooling the water in this manner may melt 500 pounds of ice within the bin A during a single day's operation, but the ice machine B will produce an additional 2000 pounds during that same period, so that a net gain of 1500 pounds is achieved.
This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention. | A storage bin for bulk ice has upper and lower sections that completely enclose a space in which ice cubes are stored. These ice cubes are produced by an ice making machine and are delivered to the ice bin by a conveyor which is inclined upwardly away from the ice making machine. One of the walls on the upper section of the ice bin is inclined to accommodate the inclination of the conveyor and this wall has an opening through which the ice cubes are discharged into the enclosed space. The lower section of the bin has an opening through which the ice cubes are withdrawn for bagging, while the upper section has another opening that provides access to the interior of the bin for breaking up ice jams. Both of these openings are normally closed by doors. Refrigeration equipment extracts heat from the enclosed space of the bin, and the water line that leads to the ice making machine passes through the space so that the water is precooled, thus rendering the ice making machine considerably more efficient. | 5 |
FIELD OF THE INVENTION
This invention relates to an improved process for the conversion of aromatic hydrocarbons, such as conversion of toluene into paraxylene. More specifically, the present invention concerns operating a disproportionation process at very low hydrogen to hydrocarbon level to promote favorable selectivity.
BACKGROUND OF THE INVENTION
The xylene isomers are produced in large volumes from petroleum as feedstocks for a variety of important industrial chemicals. The most important of the xylene isomers is para-xylene, the principal feedstock for polyester which continues to enjoy a high growth rate from large base demand. Orthoxylene is used to produce phthalic anhydride, which has high-volume but mature markets. Meta-xylene is used in lesser but growing volumes for such products as plasticizers, azo dyes and wood preservers. Ethylbenzene generally is present in xylene mixtures and is occasionally recovered for styrene production, but usually is considered a less-desirable component of C 8 aromatics.
Among the aromatic hydrocarbons, the overall importance of the xylenes rivals that of benzene as a feedstock for industrial chemicals. Neither the xylenes nor benzene are produced from petroleum by the reforming of naphtha in sufficient volume to meet demand, and conversion of other hydrocarbons is necessary to increase the yield of xylenes and benzene. Often toluene is selectively disproportionated to yield benzene and C 8 aromatics from which the individual xylene isomers are recovered.
A current objective of many petrochemical and aromatics complexes is to increase the yield of xylenes and to de-emphasize benzene production Demand is growing faster for xylene derivatives than for benzene derivatives. Refinery modifications are being effected to reduce the benzene content of gasoline in industrialized countries, which will increase the supply of benzene available to meet demand. A higher yield of xylenes at the expense of benzene thus is a favorable objective, and processes to transalkylate C 9 aromatics along with toluene have been commercialized to obtain high xylene yields.
U.S. Pat. No. 4,016,219 B1 (Kaeding) discloses a process for toluene disproportionation using a catalyst comprising a zeolite which has been modified by the addition of phosphorus in an amount of at least 0.5 mass-%. The crystals of the zeolite are contacted with a phosphorus compound to effect reaction of the zeolite and phosphorus compound. The modified zeolite then may be incorporated into indicated matrix materials.
U.S. Pat. No. 4,097,543 B1 (Haag et al.) teaches toluene disproportionation for the selective production of para-xylene using a zeolite which has undergone controlled precoking. The zeolite may be ion-exchanged with a variety of elements from Group IB to VIII, and composited with a variety of clays and other porous matrix materials.
U.S. Pat. No. 4,182,923 B1 (Chu) describes a process for toluene disproportionation with a high conversion of the toluene to benzene and paraxylene by use of an aluminosilicate zeolite of silica to alumina ratio above 12 and which has been modified by treatment with ammonium hydrogen phosphate to deposit phosphorus.
U.S. Pat. No. 4,629,717 B1 (Chao) discloses a phosphorus-modified alumina hydrogel formed by gelation of a homogeneous hydrosol. The composite has a high surface area of 140-450 m 2 /g and high activity and selectivity in 1-heptene conversion tests.
U.S. Pat. No. 6,114,592 B1 (Gajda et al.), which is incorporated herein by reference, teaches an improved process combination for the selective disproportionation of toluene. The combination comprises selective hydrogenation of a toluene feedstock followed by a zeolitic catalyst.
Workers in the field of aromatics disproportionation continue to seek processes and catalysts having exceptionally high selectivity for paraxylene from toluene combined with favorable activity and stability.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved process for the disproportionation of aromatic hydrocarbons. A specific objective is to obtain a high yield of xylenes by selective toluene disproportionation.
This invention is based on the unexpected finding that operation at very low levels of hydrogen to hydrocarbon promotes favorable selectivity to paraxylene. Soft coke that is deposited upon a catalyst at such low ratio processing can also be periodically removed by conducting periodic rejuvenation at higher molar ratios of hydrogen to hydrocarbon. Further, low ratio processing also improves the selective precoking and conditioning of zeolitic catalysts.
The present invention is directed to a process for the production of xylene comprising a selective disproportionation zone at conditions comprising a hydrogen to hydrocarbon ratio of less than 0.5. In the disproportionation zone the stream is contacted with a disproportionation catalyst at disproportionation conditions. The disproportionation catalyst preferably comprises a pentasil zeolitic aluminosilicate, most preferably MFI. This catalyst is subjected to a precoking step prior to its use in the disproportionation zone in order to increase its selectivity to paraxylene in the product beyond its equilibrium concentration.
Mixed C 8 aromatics recovered from the disproportionation effluent are sent to a xylene-separation zone; preferably, para-xylene is recovered by adsorption and/or crystallization. The xylene-separation zone may also comprise a catalytic alkyl-aromatic zone for ethylbenzene conversion and dealkylation.
Periodic disproportionation catalyst rejuvenation can also be conducted by increasing the ratio of hydrogen to hydrocarbon above 0.5, preferably to somewhere in the range of about 1 to about 5.
These as well as other objects and embodiments will become apparent from the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the yields of xylenes versus process hydrogen to hydrocarbon ratio.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A broad embodiment of the present invention is a selective toluene disproportionation process operating at low hydrogen to hydrocarbon ratio for increased selectivity to para-xylene. Accordingly, one necessary element of the process is a zeolitic catalyst which has been subjected to a precoking step, prior to its use for disproportionation, in order to deposit a controlled concentration of carbon on the catalyst and increase paraxylene selectivity. The paraxylene content of the paraxylene-rich product from disproportionation is in excess of its equilibrium concentration at disproportionation conditions.
The selective disproportionation process zone of the present invention comprises a molecular sieve and a refractory inorganic oxide. The preferred molecular sieves are zeolitic aluminosilicates, or zeolites, which may be any of those which have a SiO 2 /Al 2 O 3 ratio greater than about 10, preferably than 20, and a pore diameter of about 5 to 8 Angstroms (Å). Specific examples of zeolites which can be used are the MFI, MEL, EUO, FER, MFS, MTT, MTW, TON, MOR and FAU types of zeolites. Pentasil zeolites MFI, MEL, MTW and TON are preferred, and MFI-type zeolite, often designated ZSM-5, is especially preferred.
The preparation of the preferred MFI-type zeolite is well known in the art. The zeolite preferably is prepared by crystallizing a mixture containing an alumina source, a silica source, an alkali metal source, water and an alkyl ammonium compound or its precursor.
A refractory binder or matrix is utilized to facilitate fabrication of the disproportionation catalyst, provide strength and reduce fabrication costs. The binder should be uniform in composition and relatively refractory to the conditions used in the process. Suitable binders include inorganic oxides such as one or more of alumina, magnesia, zirconia, chromia, titania, boria, thoria, zinc oxide and silica. Alumina and/or silica are preferred binders. The amount of zeolite present in the bound catalyst can vary considerably but usually is present in an amount from about 30 to 90 mass percent and preferably from about 50 to 80 mass percent of the catalyst.
A preferred binder or matrix component is a phosphorus-containing alumina (hereinafter referred to as aluminum phosphate) component. The phosphorus may be composited with the alumina in any acceptable manner known in the art. The zeolite and aluminum phosphate binder are mixed and formed into particles by means well known in the art such as gellation, pilling, nodulizing, marumerizing, spray drying, extrusion or any combination of these techniques. A preferred method of preparing the zeolite/aluminum phosphate support involves adding the zeolite either to an alumina sol or a phosphorus compound, forming a mixture of the alumina sol/zeolite/phosphorus compound into particles by employing an oil-drop method as described here-in-below and calcining the spherical particles.
The preferred oil-drop method of preparing the aluminum phosphate is described in U.S. Pat. No. 4,629,717 B1 which is incorporated by reference. The technique described in the '717 patent involves the gellation of a hydrosol of alumina which contains a phosphorus compound using the well-known oil-drop method. Generally this technique involves preparing a hydrosol by digesting aluminum in aqueous hydrochloric acid at reflux temperatures of about 80° to 105° C. The ratio of aluminum to chloride in the sol ranges from about 0.7:1 to 1.5:1 mass ratio. A phosphorus compound is now added to the sol. Preferred phosphorus compounds are phosphoric acid, phosphorous acid and ammonium phosphate. The relative amount of phosphorus and aluminum expressed in molar ratios ranges from about 10:1 to 1:100, respectively, on an elemental basis. The zeolite is added to the aluminum phosphate hydrosol and the mixture is gelled. One method of gelling this mixture involves combining a gelling agent with the mixture and then dispersing the resultant combined into an oil bath or tower which has been heated to elevated temperatures such that gellation occurs with the formation of spheroidal particles. The gelling agents which may be used in this process are hexamethylene tetraamine, urea or mixtures thereof. The gelling agents release ammonia at the elevated temperatures which sets or converts the hydrosol spheres into hydrogel spheres. The combined mixture preferably is dispersed into the oil bath in the form of droplets from a nozzle, orifice or rotating disk. The spheres are then continuously withdrawn from the oil bath and typically subjected to specific aging and drying treatments in oil and in ammoniacal solution to further improve their physical characteristics. The resulting aged and gelled particles are then washed and dried at a relatively low temperature of about 100° to 150° C. and subjected to a calcination procedure at a temperature of about 450° to 700° C. for a period of about 1 to 20 hours.
Alternatively, the particles may be formed by spray-drying the mixture. In any event, conditions and equipment should be selected to obtain small spherical particles; the particles preferably should have an average diameter of less than about 1.0 mm, more preferably from about 0.2 to 0.8 mm, and optimally from about 0.3 to 0.8 mm.
The amount of phosphorus-containing alumina component present (as the oxide) in the catalyst can range from about 10 to 70 mass percent and preferably from about 20 to 50 mass percent. The aluminum phosphate binder/matrix optionally may contain lesser proportions of other inorganic oxides including, but not limited to, magnesia, beryllia, boria, silica, germania, tin oxide, zinc oxide, titania, zirconia, vanadia, iron oxide, chromia, cobalt oxide and the like which can be added to the hydrosol prior to dropping.
The aluminum-phosphate binder generally is amorphous, i.e., the binder material is essentially of amorphous character. Preferably less than about 10 mass-% of the binder pore volume is micropore volume, characteristic of crystalline material, and the micropore volume more preferably is less than 5% and optimally less than 2% of the pore volume. Crystalline aluminophosphate generally is an unsuitable binder material for preparing a strong, crush-resistant catalyst. Material that is not in an amorphous phase generally is present as gamma-alumina; as the phosphorus content of amorphous aluminum phosphate is decreased, therefore, the proportion of crystalline material is increased. The average bulk density of the spheres also varies with the phosphorus content, as a higher proportion of phosphorus decreases the average bulk density. Surface area also is controlled by phosphorus content: gamma-alumina oil-dropped spherical particles typically have surface areas up to about 250 m 2 /g, while spheroidal particles of aluminum phosphate may have surface areas of up to about 450 m 2 /g. Al/P atomic ratios of the binder/matrix generally range from about 1/10 to 100/1, more typically from about 1/5 to 20/1, and often between about 1:1 and 5:1.
Best results are achieved when the catalyst has an X-ray diffraction pattern showing characteristic intensities of peaks at specified Bragg angle positions. Specifically, the preferred catalyst has an X-ray powder diffraction pattern such that the ratio of peak intensities at respective two-⊖ Bragg angle positions of about 48.5:46.5 is at least about 1.1 and the ratio of peak intensities at respective two-⊖ Bragg angle values of about 48.5:47.5 is at least about 1.0. The X-ray pattern may be obtained by standard X-ray powder diffraction techniques, of which a suitable example is described hereinbelow. Typically, the radiation source is a high-intensity, copper-target, X-ray tube operated at 45 KV and 35 mA. Flat compressed powder samples illustratively are scanned in a continuous mode with a step size of 0.030° and a dwell time of 9.0 seconds on a computer-controller diffractometer. The diffraction pattern from the copper K radiation may be recorded with a Peltier effect cooled solid-state detector. The data suitably are stored in digital format in the controlling computer. The peak heights and peak positions are read from the computer plot as a function of two times theta (two-⊖), where theta is the Bragg angle.
It is within the scope of the invention that the catalyst contains a metal component, preferably selected from components of the group consisting of gallium, rhenium and bismuth. Preferably, however, the catalyst consists essentially of a zeolitic aluminosilicate having a pore diameter from about 5 to 8 Å and an aluminum phosphate binder.
The zeolitic catalyst is subjected to selective precoking to increase the proportion of paraxylene in the paraxylene-rich product above equilibrium levels at disproportionation conditions. Precoking of the present catalyst effects a proportion of paraxylene in the product above equilibrium levels at disproportionation conditions, preferably at least about 80 mass-% and optimally about 90 mass-% or more of the C 8 aromatics. Precoking is effected on a fresh or regenerated catalyst, prior to its use for disproportionation, for a time ranging from about 0.5 hours to 10 days.
The precoking is effected at conditions relative to the subsequent disproportionation step comprising one or more of a higher temperature, lower pressure, higher space velocity, and higher hydrogen to hydrocarbon ratio. Such precoking conditions comprise a pressure of from about 100 kPa to 4 MPa absolute, and a liquid hourly space velocity of from about 0.2 to 10 hr −1 . The conditions comprise one or more of an inlet temperature at least about 50° C. higher; a pressure at least about 100 kPa lower, or preferably no more than about half of the pressure utilized in the subsequent disproportionation step. Preferably the molar ratio of free hydrogen to feedstock coke-forming hydrocarbons is no more than about half of that utilized in the subsequent disproportionation step. Lower pressure and/or a lower hydrogen/hydrocarbon ratio will lower the proportion of exothermic aromatic-saturation reactions, and thus restrict the temperature rise; the result thus should be a relatively flatter temperature profile. Thus a typical temperature range would be from about 300° C. to about 700° C. and a typical hydrogen to coke-forming feed range would be about 0.01 to about 5.
It is believed that the temperature profile affects the coking rate in various parts of the catalyst bed. A steep temperature gradient therefore will effect non-uniform coke deposition, and different parts of the catalyst bed thus will be selectivated to a different extent causing poorer performance in the subsequent disproportionation step. Thus a typical temperature differential across the bed of catalyst during selective precoking would be between about a 3° C. increase and about a 4° C. decrease.
Precoking effects a catalyst coke or carbon content of between about 5 and 40 mass-% carbon, and preferably between about 10 and 30 mass-% carbon. A coke-forming feed for precoking may comprise the feedstock to the disproportionation step as described hereinbelow, such as toluene, or other specific hydrocarbons or mixtures known in the art preferably comprising aromatics may be used. Further details relative to precoking are disclosed in U.S. Pat. No. 4,097,543 B1 and U.S. Pat. No. 6,191,331 B1, incorporated herein by reference.
The feedstock to the present process comprises alkylaromatic hydrocarbons of the general formula C 6 H (6−n) R n , where n varies from 0 to 5 and R is CH 3 , C 2 H 5 , C 3 H 7 , or C 4 H 9 , in any combination to obtain more-valuable alkylaromatics. Suitable alkylaromatic hydrocarbons include, for example but without so limiting the invention, benzene, toluene, xylenes, ethylbenzene, trimethylbenzenes, ethyltoluenes, propylbenzenes, tetramethylbenzenes, ethyldimethylbenzenes, diethylbenzenes, methylpropylbenzenes, ethylpropylbenzenes, triethylbenzenes, di-isopropylbenzenes, and mixtures thereof.
The feedstock preferably comprises toluene, optionally in combination with C 9 aromatics, and suitably is derived from one or a variety of sources. Feedstock may be produced synthetically, for example, from naphtha by catalytic reforming or by pyrolysis followed by hydrotreating to yield an aromatics-rich product. The feedstock may be derived from such product with suitable purity by extraction of aromatic hydrocarbons from a mixture of aromatic and nonaromatic hydrocarbons and fractionation of the extract. For instance, aromatics may be recovered from a reformate. The reformate may be produced by any of the processes known in the art, with a process based on platinum containing L-zeolite being especially preferred for light aromatic production. The aromatics then may be recovered from the reformate through the use of a selective solvent, such as one of the sulfolane type, in a liquid-liquid extraction zone. The recovered aromatics may then be separated into streams having the desired carbon number range by fractionation. The feedstock should contain no more than about 10 mass-% non-aromatics; the content of benzene and C 8 aromatics is principally an economic decision relating to the dilution of toluene from these aromatics. When the severity of reforming or pyrolysis is sufficiently high, extraction may be unnecessary and fractionation may be sufficient to prepare the feedstock.
A preferred component of the feedstock is a heavy-aromatics stream comprising C 9 aromatics, thereby effecting transalkylation of toluene and C 9 aromatics to yield additional Xylenes. Benzene may also be transalkylated to yield additional toluene. Indane may be present in the heavy-aromatics stream although it is not a desirable component to effect high yields of C 8 -aromatics product. C 10 +aromatics also may be present, preferably in an amount of 30% or less of the feed. The heavy-aromatics stream preferably comprises at least about 90 mass-% aromatics, and may be derived from the same or different known refinery and petrochemical processes as the benzene and toluene feedstock and/or may be recycled from the separation of the product from transalkylation.
Within the disproportionation process the feed usually is first heated by indirect heat exchange against the effluent of the reaction zone and is then further heated in a fired heater. The resulting vaporous stream is then passed through a reaction zone which may comprise one or more individual reactors. The use of a single reaction vessel having a fixed cylindrical bed of catalyst is preferred, but other reaction configurations utilizing moving beds of catalyst or radial-flow reactors may be employed if desired. Passage of the combined feed through the reaction zone effects the production of a vaporous effluent stream comprising hydrogen and both product and unconverted feed hydrocarbons. This effluent is normally cooled by indirect heat exchange against the stream entering the reaction zone and then further cooled through the use of air or cooling water. The temperature of the effluent stream generally is lowered by heat exchange sufficiently to effect the condensation of substantially all of the feed and product hydrocarbons having six or more carbon atoms per molecule. The resultant mixed-phase stream is passed into a vapor-liquid separator wherein the two phases are separated and from which the hydrogen-rich vapor is recycled to the reaction zone. The condensate from the separator is passed into a stripping column in which substantially all C 5 and lighter hydrocarbons present in the effluent are concentrated into an overhead stream and removed from the process. An aromatics-rich stream which is referred to herein as the disproportionation effluent stream is recovered as net stripper bottoms.
Conditions employed in the disproportionation process zone normally include a temperature of from about 200° to 600° C., and preferably from about 350° C. to about 575° C. The temperature required to maintain the desired degree of conversion will increase as the catalyst gradually loses activity during processing. Normal end-of-run temperatures may therefore exceed start-of-run temperatures by 65° C. or more.
The disproportionation zone is generally operated at hydrogen to hydrocarbon ranges about 0.2 to about 0.5. The ratio of hydrogen to hydrocarbon is calculated based on the molar ratio of free hydrogen compared against the feedstock hydrocarbon. Periodic increases in hydrogen to hydrocarbon above 0.5, and preferably in the range of 1 to 5 permit catalyst rejuvenation by hydrogenation of soft coke.
The disproportionation zone is operated at moderately elevated pressures broadly ranging from about 100 kPa to 6 MPa absolute. A preferred pressure range is from 2 to 3.5 MPa. The disproportionation reaction can be effected over a wide range of space velocities, with higher space velocities effecting a higher ratio of paraxylene at the expense of conversion. Liquid hourly space velocity generally is in the range of from about 0.2 to 20 hr −1 .
The disproportionation effluent stream is separated into a light recycle stream, a paraxylene-rich mixed-C 8 -aromatics product and a heavy-aromatics stream. The paraxylene-rich product may be sent to a xylene separation zone for recovery of pure paraxylene; optionally, other xylenes and ethylbenzene also may be recovered as pure products. The paraxylene-rich stream preferably contains paraxylene in proportion to total xylenes in excess of its equilibrium concentration at disproportionation conditions, more preferably at least 80 mass-% paraxylene, and most preferably at least about 85 mass-% paraxylene. The light recycle stream may be diverted to other uses such as to benzene and toluene recovery, but optionally a portion is recycled since it contains not only benzene and toluene but also amounts of non-aromatics which would remain with the benzene and reduce its commercial value. The heavy recycle stream contains substantially all of the C 9 and heavier aromatics and may be either withdrawn as a product of the process or partially or totally recycled to the feedstock.
The xylene-separation zone may utilize one or more different separation techniques such as fractionation, crystallization or selective adsorption to recover pure paraxylene from the paraxylene-rich stream in the xylene-separation zone. Conventional crystallization is disclosed in U.S. Pat. No. 3,177,255 B1, U.S. Pat. No. 3,467,724 B1 and U.S. Pat. No. 3,662,013 B1. Various other crystallization alternatives are discussed in U.S. Pat. No. 5,329,061 B1, incorporated by reference. In an embodiment in which the paraxylene-rich product has a paraxylene content substantially in excess of the equilibrium concentration, recovery of pure paraxylene may be effected using only a single stage of crystallization corresponding to the higher-temperature purification stage of conventional crystallization.
An alternative separation zone comprises a bed of molecular sieves operated in accordance with the teaching of U.S. Pat. No. 3,201,491 B1 to simulate the use of a continuously moving bed of molecular sieves. Subsequent improvements to the process are described in U.S. Pat. No. 3,696,107 B1 and U.S. Pat. No. 3,626,020 B1. Details on the operation of the xylene-separation zone may be obtained from U.S. Pat. No. 4,039,599 B1 and U.S. Pat. No. 4,184,943. The xylene-separation zone may also incorporate a catalytic alkyl-aromatic isomerization zone within the separation loop, in order to shift the isomers of ortho- and meta-xylene towards para-xylene, as well as to isomerize ethyl benzene to xylene or else to dealkylate it to benzene. The benzene produced here may also be sent to the transalkylation zone. The xylene separation zone may also employ a simulated concurrent adsorptive separation process of U.S. Pat. No. 4,402,832 B1. The extract and raffinate streams may be handled as described in these references or as described in U.S. Pat. Nos. 4,381,410 and 5,495,061 B1.
The skilled routineer will recognize variations in the process combination described above which are within the scope of the invention. For example, benzene as well as toluene may be charged to the disproportionation zone as a supplementary feedstock. The xylene-separation zone may use one or more of several known separation techniques such as adsorption, crystallization and fractionation. Orthoxylene and/or metaxylene may be recovered by one or more of such techniques as pure products from the xylene-separation zone.
The catalyst may be subjected to precoking either in-situ or ex-situ in order to increase the proportion of paraxylene in the C 8 aromatics product.
The process of disproportionation may be carried out until the catalyst conversion is no longer economically favorable due to catalyst decline, deterioration, or deactivation. A typical economic target occurs when the initial conversion of the catalyst has decreased by 2% or greater, at which point the catalyst is rejuvenated by increasing the molar ratio of free hydrogen to feedstock hydrocarbons to greater than 0.5. Preferred rejuvenation conditions include free hydrogen present in a molar ratio to feedstock hydrocarbons of about 1 to about 5, an inlet temperature from about 200 to about 600° C., a pressure of from about 100 kPa to about 6 MPa absolute, and a liquid hourly space velocity of about 0.2 to about 10 hr −1 . Moreover, the optimum initial conversion level for low levels of hydrogen to hydrocarbon ratio such as 0.2, may vary from about 26% to about 36%, more preferably from about 30% to about 34%.
EXAMPLES
The following examples are presented to demonstrate the present invention and to illustrate certain specific embodiments thereof. These examples should not be construed to limit the scope of the invention as set forth in the claims. There are many possible other variations, as those of ordinary skill in the art will recognize, which are with the spirit of the invention.
Example I
An alumina-phosphate-bound MFI catalyst was prepared to evaluate the invention. A first solution was prepared by adding phosphoric acid to an aqueous solution of hexamethylenetetraamine (HMT) in an amount to yield a phosphorus content of the finished catalyst equal to about 3.8 mass-% and an aluminum: phosphorus atomic ratio in the binder of about 1:1. A second solution was prepared by adding an MFI-type zeolite having a Si/Al 2 ratio of about 39 to enough alumina sol, prepared by digesting metallic aluminum in hydrochloric acid, to yield a zeolite content in the finished catalyst equal to about 70 mass-%. These two solutions were commingled to achieve a homogeneous admixture of HMT, phosphorus, alumina sol, and zeolite. The admixture was dispersed as droplets into an oil bath maintained at about 93° C. The droplets remained in the oil bath until they set and formed hydrogel spheres having a diameter of about 1.6 mm. The spheres were removed from the oil bath, water washed, air dried, and calcined at a temperature of about 650° C. This disproportionation catalyst was utilized in the precoking and disproportionation tests described hereinafter.
Example II
The catalyst was then precoked at conditions comprising a temperature of about 560° C., a pressure of 0.72 MPa and 4 weight hourly space velocity (WHSV) in the presence of a 1:0.5 hydrogen:hydrocarbon molar ratio for a period of time sufficient to effect approximately 90 mole-% paraxylene in total xylenes. Disproportionation of pure toluene then was carried out at 2.45 MPa and 4 WHSV in the presence of pure hydrogen at varying temperatures as red to achieve 30% conversion of toluene. Data-points were recorded at hydrogen to hydrocarbon ratios 3.0, 2.0, 1.0, 0.5 and 0.2 in order to illustrate the ion. Results then were normalized based on pilot-plant correlations to de comparative yields of benzene and xylenes in the product at 30% conversion. FIG. 1 indicates the increased para-xylene yield obtained with disportionation at ratios of hydrogen to hydrocarbon below 0.5. | An improved process is disclosed for the selective disproportionation of toluene. The process preferably uses a disproportionation catalyst comprising MFI bound with alumina phosphate. Running the process at a hydrogen to hydrocarbon ratio between 0.2 to 0.5 improves the yield of para-xylene. Optional periodic rejuvenation by increasing the hydrogen to hydrocarbon ratio removes some carbon deposits and restores catalyst activity. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to new methods and drugs for ameliorating insulin resistance in skeletal muscle, a major contributing abnormality to impaired glucose handling in such diseases as type 1 and 2 diabetes, hypertension, obesity and critical care patients. A number of drugs currently in use modify insulin release and/or insulin action, which may include the skeletal muscle but none specifically acts to improve muscle capillary blood flow in the immediate sense. This invention provides a new series of drugs and methods specifically targeted to ameliorating insulin resistance by increasing capillary blood flow in muscle. The central tenet is that by so acting, access for insulin and all nutrients is enhanced.
BACKGROUND OF THE INVENTION
[0002] Approximately 80% of the post-absorptive glucose that enters the blood stream from a meal is taken up by the muscles. The rise in blood glucose in the post-absorptive state triggers the release of insulin from the pancreas and this acts on both the liver (to suppress glucose output) and skeletal muscle (to enhance glucose uptake). A reduced ability of the muscle to respond to insulin constitutes insulin resistance for this tissue and because so much of the post-absorptive glucose is intended for muscle, the blood glucose level rises. An immediate effect of the hyperglycaemia is further stimulus of the pancreas to release more insulin and so hyperinsulinaemia can also occur. As time progresses and if left untreated, sequelae develop, including small and large vessel disease. The pancreas may become exhausted giving rise to type 2 diabetes. Insulin resistance in muscle may also have its origins from low physical activity and/or over-eating (obesity), stress (hypertension and critical care patients) or excessive lipid levels in the blood (hyperlipidaemias).
[0003] Most researchers currently regard insulin resistance to be the result of impaired insulin signalling or impaired glucose transport (abnormalities in GLUT4 translocation) in the myocytes that constitute the muscle fibres. Only a few research groups support the notion that delivery of insulin and glucose to the myocytes is rate-limiting and their support is based on a key role for total blood flow (see below). The absence of techniques for determining changes in capillary recruitment as these relate to insulin action in normal healthy individuals and impairment in insulin resistant states has prevented other researchers from becoming aware of the key role of capillary recruitment.
[0004] Techniques for measuring limb blood (or total blood) flow in vivo that give reproducible results have been available since 1990. Thus, prior to the applicants' work interest in the general area of insulin/glucose delivery to muscle has largely focused on the role of total blood flow to limbs. A number of laboratories have reported an effect of insulin to increase total blood flow to muscle and that this effect is impaired in states of insulin resistance (1-3). However, the role of the increase in total blood flow mediated by insulin is controversial. Several research groups claim that insulin-mediated changes in total blood flow relate poorly to muscle glucose uptake under a number of circumstances, including insulin dose and time course (4-6). In addition, there have been studies where total flow changes persist when glucose uptake is inhibited (7,8). Also, most vasodilators that augment total blood flow to the limbs do not enhance insulin action nor do they overcome insulin resistance (9,10).
[0005] The applicants have conducted research in developing new techniques specifically for the measurement of changes in nutritive capillary blood flow in muscle. The idea for these methods grew out of a series of studies using the perfused rat hindlimb where it was established that a tight link between the proportion of nutritive/non-nutritive blood flow in skeletal muscle and metabolism as well as between the proportion of flow and exercise performance exists. From those studies it was realised that hormone and nutrient access was a central process in controlling both muscle metabolism and function. It has been shown that restriction of insulin and glucose access by pharmacologically manipulating flow to be predominantly non-nutritive, created a state of insulin resistance. This was an important observation because it illustrated the marked effect that reduced access for hormone and substrate could play in controlling down-stream metabolism. The search then began for a method, or methods that could detect changes in the proportion of nutritive (capillary) to non-nutritive blood flow in this tissue that might have application in vivo and ultimately to humans. Marker enzymes located in one or other of the two vascular networks (nutritive or non-nutritive) were to provide the key. Thus the first method involved 1-methylxanthine (1-MX), as an exogenous substrate for xanthine oxidase, an enzyme shown by others to reside predominantly in capillary (nutritive) endothelial cells (11). 1-MX was infused intra-arterially and its metabolite 1-methyl urate measured in venous blood by HPLC. Since there was no uptake by the tissue of either the substrate or the product, the extent of conversion was a reflection of capillary exposure. Characterisation under a number of conditions revealed that 1-MX metabolism was indeed directly proportional to nutritive, or capillary flow, which in the constant-flow perfused hindlimb system could be altered by applying various vasoconstrictors or by simulating exercise (12,13). The 1-MX method was tested in vivo using the hyperinsulinaemic euglycaemic clamp in rats and it has been shown for the first time that insulin acted directly to recruit capillary flow in muscle (14) and that pharmacological manipulation to decrease the proportion of nutritive blood flow by an infused vasoconstrictor, created a state of insulin resistance (15). These latter findings directly linked blood pressure through blood redistribution to insulin resistance in vivo a situation that has been reported from a number of epidemiological studies of human populations in the past. In addition, a close link between capillary recruitment and muscle glucose uptake began to emerge from these and previous 1-MX studies.
[0006] A second method was devised using the latest technologies in ultrasound. The ultrasound method relies on the increased echogenicity of albumin microbubbles which are continuously infused intravenously during data acquisition. The acoustic signal that is generated from the microbubbles when exposed to ultrasound produces tissue opacification which is proportional to the number of microbubbles within the ultrasound beam. Using harmonic pulsing methods essentially all microbubbles within the ultrasound beam are destroyed in response to a single pulse of high-energy ultrasound and an image is obtained. In the time interval between subsequent pulsing episodes, microbubbles flowing into the tissue are replenished within the beam and affect the intensity of the signal from the next high energy pulse. Repeating this process with pulse delays between 50 msec and 20 sec, the beam will be fully replenished and further increases in the time between each pulsing interval will not produce a change to tissue opacification. The rate of microbubble reappearance within the ultrasound beam provides an indication of capillary velocity and the degree of tissue opacification provides a measurement of capillary blood volume (CBV). Images are background-subtracted from images from a pulsing interval of 1000 ms which represents the replenishment of arteries and arterioles thus providing a measurement of capillary flow. The plateau tissue opacification (measured as videointensity) is the determination of capillary blood volume. Using this approach, changes in capillary blood volume in response to insulin and exercise have recently been assessed in the skeletal muscle of the rat hindlimb in vivo and compared to data obtained using 1-MX metabolism (ref 16; FIG. 1). FIG. 1. Comparison of the effect of saline, insulin (3 mU/min/kg, euglycemic clamp ×120 min) or muscle contraction (2 Hz, 1 ms duration, monophasic square waves ×10 min) on capillary blood volume as measured by microbubble videointensity using contrast enhanced ultrasound (FIG. 1 a ) or the hindlimb extraction of 1-MX (FIG. 1 b ) measured under identical conditions. Values are means±SE. *, significantly different from saline. Compared to baseline values, saline-infusion resulted in little change in capillary blood volume whereas marked increases in capillary blood volume occurred during euglycemic insulin clamp (3 mU/min/kg), or exercise. This is particularly important as it shows that insulin has an exercise-like effect to recruit capillary blood flow. Exercise is regarded by most physiologists as a “bench-mark” stimulus for capillary recruitment. In addition, FIG. 1 shows that that CEU data correlates well with 1-MX metabolism data. A particular advantage of the ultrasound method is that it is relatively non-invasive and is suitable for human use (17). This opens up possibilities for its use in diagnosis in terms of impaired capillary recruitment in response to insulin and the monitoring of outcomes from therapeutic interventions that might act by increasing capillary recruitment.
[0007] The third approach is laser Doppler flowmetry (LDF), where this has already been used for a number of years to study skin blood flow. The applicants have determined that the signal strength from relatively large probes (800 μm), when measured over muscle, directly related to the extent of nutritive flow in the constant flow perfused rat hindlimb. Thus vasoconstrictors that increase metabolism in this preparation increase the LDF signal (18). Conversely, vasoconstrictors that decrease metabolism, also decrease LDF signal (18). Importantly, when under the euglycemic hyperinsulinemic clamp in vivo the laser Doppler signal increased coincident with insulin-mediated increases in glucose infusion (19). Again, this would appear to confirm findings with 1-MX and CEU that insulin mediates a marked capillary recruitment in rat muscle as part of its action in vivo.
[0008] The applicant's findings show the following:
[0009] Firstly, insulin-mediated capillary recruitment occurs within 5-10 minutes after the commencement of insulin infusion in vivo (20) and is thus an early event.
[0010] Secondly, the capillary recruitment mediated by insulin occurs at physiological levels of insulin both in rats and human forearm. When supra-physiological doses of insulin are used there is an increase in total blood flow to the muscles, but this occurs after the increase in capillary recruitment. It appears possible, that the increase in total blood flow to muscle is the result of capillary recruitment. That the increase in capillary recruitment due to insulin occurs independently of an increase in total blood flow suggests that blood has been redirected from the normutritive route to the nutritive capillary network.
[0011] Thirdly, blockade of the insulin-mediated capillary recruitment in vivo by either pharmacological manipulation to recruit predominantly non-nutritive blood flow (15), or by treatment of the rats with the inflammatory cytokine, TNFα ((21), led to marked insulin resistance with approx. 50% of the muscle glucose blocked. These findings strongly suggest that insulin-mediated capillary recruitment which increases insulin and glucose access to the myocytes, accounts for about half of the insulin-mediated glucose uptake by muscle in vivo.
[0012] Fourthly, in the obese Zucker rat and obese human forearm there is marked impairment of insulin-mediated capillary recruitment that accompanies approximately 50% loss of insulin-mediated glucose uptake.
[0013] Fifthly, voluntary exercise training of our local strain of rats for a period of two weeks significantly improves both insulin-mediated muscle glucose uptake and capillary recruitment.
[0014] Finally, when all of the data is pooled for the animal studies and muscle glucose uptake is plotted in relation to capillary recruitment a significant correlation is evident (FIG. 2). FIG. 2. Pooled data for in vivo clamps in rats showing correlation between leg glucose uptake and 1-MX disappearance (capillary recruitment).
R 2 =0.71
[0015] No significant correlation results when muscle glucose uptake is plotted in relation to total limb blood flow (FIG. 3). FIG. 3. Relationship between hindlimb FBF and glucose uptake.
R 2 =0.37
[0016] Accordingly, drugs targeted at increasing muscle capillary blood flow will increase muscle glucose uptake. Moreover, amelioration of an impaired ability of insulin to recruit capillary blood flow in muscle by a new drug will have a significant impact on reversing insulin resistance.
[0017] Mechanisms by Which Insulin Acts to Recruit Capillary Blood Flow in Muscle as Indicators to Possible New Drugs Intended to Manipulate This Process.
[0018] From present knowledge there would appear to be at least three possible mechanisms to account for insulin-mediated capillary recruitment in skeletal muscle. Firstly and most likely, insulin may act at insulin receptors on endothelial cells and an IRS-1/2, P13-K pathway to activate eNOS to produce NO, which in turn permeates adjacent vascular smooth muscle cells to activate soluble guanylyl cyclase and lower the vascular tone of pre-capillary sphincters. In favour of this mechanism is the fact that this process is NO-dependent and is thus consistent with our preliminary data (FIG. 4). There is compelling evidence that insulin acts directly through insulin receptors on endothelial cells to control nutritive capillary flow in skin. Secondly, insulin may act at insulin receptors on the vascular smooth muscle cells (22) via IRS-1/2, P13-K, NOS, cGMP, MBP (myosin bound phosphatase) sequence to cause vasorelaxation. This mechanism would be NO-dependent, free of endothelial cell involvement in signalling and attractive as TNFα is known to inhibit insulin signalling in vascular smooth muscle cells, although to date this has been restricted to the ERK1/2 activation step (23). This mechanism would also lead ultimately to the activation of guanylyl cyclase and the production of cyclic GMP. Thirdly, insulin may act at insulin receptors on skeletal muscle to activate glucose transport and metabolism by the IRS-1/2, P13-K, GLUT4 pathway to produce a metabolite (e.g. adenosine) that permeates adjacent tissue to react with appropriate receptors on endothelial/vascular smooth muscle cells to result in vasorelaxation. This need not involve NO and cyclic GMP, but the applicants have data to show that insulin-mediated capillary recruitment is NO-ependent (FIG. 4). FIG. 4. The effect of L-NAME on insulin mediated increases in hindleg glucose uptake (FIG. 4 a ) and 1-MX metabolism (FIG. 4 b ) was examined. Euglycemic clamp conditions (10 mU/min/kg) were conducted for 2h. Values are means±SEM for n=5 for each group. *, significantly different from SALINE. #, significantly different from insulin (INS)+L-NAME. L-NAME also blocked the increase in FBF and raised the mean arterial blood pressure from 100±4 to 125±5 mmHg. This latter mechanism would resemble that occurring in exercise where vasodilatory metabolite(s) are released locally by working muscle to facilitate local blood flow and would be inhibited by agents (e.g. glucosamine) that inhibit muscle glucose metabolism. All three mechanisms should be wortmannin sensitive as P13-K is expected to be involved. A variant of this third mechanism is where a form of NOS is activated in skeletal muscle independently of glucose metabolism. NO could then permeate neighbouring tissue as above. The terminal half of this fourth possible mechanism should be simulated by AMPK activation with AICAR addition (24). Overall, given that the mechanism of capillary recruitment by insulin in rat muscle is NO-dependent (FIG. 4) and that NO acts by producing cyclic GMP, agents that might enhance capillary recruitment by insulin should be targeted to enhance insulin's production of NO or cyclic GMP.
[0019] Thus the concept of a new drug(s) that targets muscle capillary blood flow, either acting directly or by enhancing the action of insulin in this respect, where this is impaired in insulin resistance, is the product of the results outlined above. However, there are also parallels to sildenafil (Viagra®), in its capacity to increase blood flow specifically to the corpus cavernosum, and to exercise in causing reactive hyperaemia in working muscles (FIG. 1). Research using the isolated perfused rat hindlimb indicates that when total blood flow does not change, capillary recruitment (or increased nutritive flow) can only occur as a result of flow being switched from the non-nutritive route. Thus the use of a blanket nitrovasodilator, such as nitrprusside etc. is inappropriate. All points in the two vascular routes where tone is maintained are dilated and invariably this favours flow in the route of least intrinsic resistance, which is non-nutritive. A number of research groups have shown that vasodilators (with the possible exception of methacholine), do not increase muscle glucose uptake even though they increase total limb blood flow in vivo, and they do not ameliorate insulin resistance. Novel drugs aimed at increasing nutritive capillary blood flow would act by specifically relaxing sites controlling entry to the nutritive route, and or maintaining or intensifying constriction at sites controlling entry to the non-nutritive route. Exercise is able to achieve this, sildenafil probably does not as a non-nutritive route probably does not contribute in a major way to the blood supply of the corpus cavernosum.
SUMMARY OF THE INVENTION
[0020] In a first aspect the invention provides a method of screening compounds for the ability to increase capillary blood flow, the method comprising:
[0021] (a) taking a first measurement of capillary blood flow in a subject;
[0022] (b) administering a compound to said subject;
[0023] (c) taking a second measurement of capillary blood flow in said subject, and
[0024] (d) comparing said first and second measurements,
[0025] wherein a positive difference between said first and second measurements indicate the ability of said compound to increase capillary blood flow.
[0026] The measurements of capillary blood flow preferably comprise:
[0027] administering an ultrasound contrast medium to said subject such that said contrast medium reaches the microvascular capillaries in said subject measuring microvascular capillary blood flow volumes and/or microvascular flow velocity index of said capillaries;
[0028] applying a defined signal to said subject;
[0029] measuring changes to said microvascular capillary flow where in the measurement is made by ultrasound imaging.
[0030] The administration step above may be preceded by administration of insulin.
[0031] The defined signal may include any signal potentially or actually capable of affecting microvascular capillary flow.
[0032] The screening, when applied to a human subject, may be preceded with a similar screening in another animal of similar biochemistry to the human, for example a rat, so as to minimise unnecessary testing on humans.
[0033] As an alternative to the above steps (a) to (d) a 1-MX assay could be used.
[0034] The compounds most useful is treating insulin resistance would form the basis of active ingredients in drugs for treating insulin resistance in patients.
[0035] In another aspect the invention provides a diagnostic method of tracing microvascular capillary flow response by using the above screening method or capillary flow method in steps (a) to (d) thereby allowing the impact of an agent or compound on said capillary flow to be determined.
[0036] In another aspect the invention provides a method of ameliorating the symptoms of insulin resistance in skeletal muscle comprising the administration to said muscle of a drug adapted to improve (increase) insulin—mediated capillary recruitment therein.
[0037] The drug may take any physiologically acceptable form and is most preferably administered in conjunction with insulin. The insulin may be derived endogenously or exogenously.
[0038] The drug may act acutely, that is within the same time course as insulin, to increase insulin access in real time along with an increase in access of nutrients to myocytes as a result of the recruitment of capillary blood flow.
[0039] The drug may act chronically to alter gene expression in a manner such that after several days or weeks of administration of the drug the subsequent ability of insulin to recruit capillary blood flow is improved.
[0040] The drug may also be adapted to inhibit cyclic GMP breakdown in terminal arterioles-controlling blood flow to nutritive capillaries.
[0041] The drug may also be adapted to enhance production of NO at the same sites as those stimulated by insulin, immediately proximal to the terminal arterioles controlling blood flow to the nutritive capillaries.
[0042] The drug may also be adapted to increase muscle glucose metabolism to provide vasodilators that increase NO to dilate the terminal arterioles controlling blood flow to the nutritive capillaries.
[0043] The drug may also be adapted to alter gene expression including induction and/or repression of enzyme systems involved with production of NO in endothelial cells.
[0044] The drug may also enhance focal production of NO and/or endogenous vasodilators.
[0045] The drug may also act on site-specific delivery of micro-encapsulated nitrovasodilator.
[0046] The drug may act by blocking blood substances affecting the ability of insulin to recruit capillary flow.
[0047] The drug may act via a central mechanism to modify vasomotor neural output.
[0048] In another aspect the invention provides a drug screened in accordance with the above method, particularly when used to ameliorate the symptoms of insulin resistance including diabetes, types 1 and 2 , hypertension, obesity and critical care patients.
[0049] In another aspect the invention provides the above drugs when used in conjunction with insulin.
DETAILED DESCRIPTION OF THE INVENTION
[0050] In order that the nature of the present invention may be more clearly understood preferred forms thereof will now be described with reference to the following non-limiting examples.
[0051] Methods for Detecting Insulin-Mediated Capillary Recruitment and Therefore the Means by Which the Present Invention Acts.
[0052] In laboratory rats three methods have been used by the applicants to demonstrate that insulin acts to recruit muscle capillary blood flow as part of its normal action in vivo. These are 1-MX (14), CEU/microbubbles (FIG. 1) and LDF (19). Only LDF has been used before by other researchers for this purpose but this has been to assess capillary blood flow changes in human skin. The other two methods 1-MX and CEU/microbubbles are unique to the applicants' and the subject of co-pending applications.
[0053] In humans, at this point in time, the CEU/microbubbles method can be used and approval has been granted for use of 1-MX in humans by the Danish authorities. The applicants and their collaborators are applying for wider approval to infuse 1-MX in humans so that the 1-MX method can be used generally.
[0054] The 1-MX Method
[0055] In principle, 1-methylxanthine (1-MX) is an exogenous substrate for an enzyme located predominantly in the nutritive capillary endothelial cells (much less so in the non-nutritive route and myocytes). Consequently, passage of blood borne 1-MX through the nutritive vascular route leads to its conversion to the product 1-methylurate (1-MU). Chromatographic analysis of arterial and venous samples for 1-MX and 1-MU together with the total blood flow rate over the muscle bed allows the calculation of 1-MX metabolism. A number of our studies using the perfused rat hindlimb have shown tight correlation between nutritive flow (or the proportion of nutritive/non-nutritive flow) and 1-MX metabolism (12,13).
[0056] From in vivo studies in rats using the hyperinsulinaemic euglycaemic clamp the applicants have shown that insulin acts to recruit capillary flow in muscle (14). Deliberate impairment of capillary recruitment in an animal model gives rise to insulin resistance (15). At least one model of muscle insulin resistance in animals shows impaired insulin-mediated capillary recruitment (Zucker rat, unpublished). Exercise-training which is beneficial in treating and preventing muscle insulin resistance leads to enhanced insulin-mediated capillary recruitment (unpublished).
[0057] Contrast Enhanced Ultrasound/Microbubbles (CEU) Method
[0058] The ultrasound method relies on the increased echogenicity of albumin microbubbles that are continuously infused intravenously during data acquisition. The acoustic signal that is generated from the microbubbles when exposed to ultrasound produces tissue opacification that is proportional to the number of microbubbles within the ultrasound beam. Using harmonic pulsing methods essentially all microbubbles within the ultrasound beam are destroyed in response to a single pulse of high-energy ultrasound and an image is obtained. In the time interval between subsequent pulsing episodes, microbubbles flowing into the tissue are replenished within the beam and affect the intensity of the signal from the next high-energy pulse. Repeating this process with pulse delays between 50 msec and 20 sec, the beam will be fully replenished and further increases in the time between each pulsing interval will not produce a change to tissue opacification. The rate of microbubble reappearance within the ultrasound beam provides an indication of capillary velocity and the degree of tissue opacification provides a measurement of capillary blood volume (CBV or MW).
[0059] Images are background-subtracted from images from a pulsing interval of 1000 ms which represents the replenishment of arteries and arterioles thus providing a measurement of capillary flow. The plateau tissue opacification (measured as videointensity) is the determination of capillary blood volume. Using this approach, changes in capillary blood volume in response to insulin and exercise have recently been assessed in the skeletal muscle of the rat hindlimb in vivo and compared to data obtained using 1-MX metabolism (16; FIG. 1). Compared to baseline values, saline-infusion resulted in little change in capillary blood volume whereas marked increases in capillary blood volume occurred during euglycemic insulin clamp (3 mU/min/kg). Recent studies have demonstrated that CEU data correlates well with 1-MX metabolism data, and that capillary blood volume increases-2-3 fold during these physiologic doses of insulin (16). A particular advantage of the ultrasound method is that it is relatively non-invasive and is suitable for human use (17).
[0060] Assay of new drugs acting to increase capillary recruitment in the presence of endogenous or exogenous insulin. This is done in an optional two tier manner, firstly in anaesthetized rats using the hyperinsulinaemic euglycaemic clamp (14) and secondly, in human forearm using a localized hyperinsulinaemic euglycaemic clamp (17). The initial testing in rats is optional, but allows rapid identification of those agents likely to be effective in humans. Typically the means of assay in rats would involve infusion of a physiological dose of insulin that is sub-maximal (e.g. 3 mU/min/kg body weight) in animals that are instrumented to allow continuous monitoring of blood pressure, heart rate and femoral arterial blood flow. The drug to be tested would be infused commencing 1 hour before the infusion of insulin. Arterial blood samples will be taken for glucose analyses in order to check that if the drug increases glucose disposal without insulin infusion. Either way and within 10 minutes of commencing the infusion of the insulin, glucose infusion would be commenced. By assaying arterial blood samples every 15 minutes, the glucose infusion is adjusted to maintain euglycaemia (i.e. 5 mM). In the second hour of the 2 hour clamp markers for muscle glucose uptake (radiolabelled 2-deoxyglucose) and capillary recruitment (1-MX) are infused. At the end of the clamp, arterial and femoral vein blood samples are taken from which capillary recruitment and leg glucose uptake can be calculated from glucose and 1-MX values respectively. Muscles of the lower leg are also removed and the radioactivity therein used to calculate muscle specific glucose uptake. A drug enhancing insulin's action to increase muscle glucose uptake would be expected to increase each of the following: glucose infusion to maintain euglycaemia, leg glucose uptake, muscle specific glucose uptake, and capillary recruitment as indicated by increased 1-MX metabolism (or disappearance). Data for two founder drugs, zaprinast [1,4-dihydro-5-(2-propoxyphenyl)-7H-1,2,3-triazolo(4,5-d)pyrimidin-7-one] and AICAR [5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside] are shown in FIGS. 5 and 6, respectively. Zaprinast significantly (P<0.05) enhanced insulin-mediated capillary recruitment (1-MX metabolism), glucose appearance (Ra) and glucose disposal (Rd) (FIG. 5). FIG. 5. In this study zaprinast is infused into anaesthetised rats in conjunction with a sub maximal physiologic dose of insulin. FIG. 5 a shows that zaprinast enhances insulin-mediated capillary recruitment as indicated by hindleg 1-MX metabolism. Zaprinast also enhanced insulin-mediated glucose appearance (Ra) and most importantly, glucose disposal (Rd). These changes were statistically significant with P<0.05.AICAR recruited capillary flow on its own and when added with insulin, markedly enhanced hindleg glucose uptake (FIG. 6). FIG. 6. In this study AICAR was infused into anaesthetised rats either alone (FIG. 6 a ) or with insulin (FIG. 6 b ). AICAR increased capillary recruitment as indicated by CEU and enhanced insulin-mediated hindleg glucose uptake (P<0.05). Drugs of greatest interest will be those that ameliorate insulin resistance in any one of a number of insulin resistant animal models. These might include the genetically obese Zucker rat, and the Intralipid®-infused rat.
[0061] Second tier testing of those drugs found to act by enhancing insulin-mediated capillary recruitment in rats are to be tested in humans using the forearm clamp and contrast enhanced ultrasound/microbubbles (CEU) (17). The drug, in a form suitable for oral administration, would be taken one to two hours prior to testing. The patient's response would be tested on two occasions, one with and one without drug administration and the two results compared. Typically, in response to low doses of insulin 0.01 to 0.05 mU/min/kg infused locally into the brachial artery, plasma insulin rises by 70-350 pM in blood perfusing forearm muscle with little or no effect on the systemic insulin, glucose, FFA, catecholamines or amino acid concentrations. As a result, the isolated effect of local insulin on total blood flow into the arm and glucose balance across the arm can be measured. In addition, capillary recruitment in the forearm flexor muscle can be measured using CEU. Total forearm blood flow is measured on the subject by two techniques: capacitance plethysmography and brachial artery ultrasound. For the Doppler flow measurements, an ultrasound system (Sonos 5500, Hewlett-Packard, Andover, Mass.) with a linear-array transducer is used with a transmit frequency of 7.5 MHz to allow 2-D imaging of the brachial artery in the long axis. Brachial artery diameter is measured 2 cm proximal to the tip of the arterial catheter at peak systole using online video calipers. A pulsed-wave Doppler sample blood volume is placed at the same location in the center of the vessel and the mean brachial artery blood velocity measured using on-line angle correction and analysis software. Brachial artery blood flow is calculated from 2-D Doppler ultrasound data using the equation: Q=v□·(d/2) 2
[0062] To measure capillary recruitment with CEU, a suspension of albumin microbubbles is infused intravenously in the contra-lateral arm while 2D imaging of the deep flexor muscles of the test forearm is performed. Measurement is made in a trans-axial plane 5 cm distal to be antecubital fossa, using an ultrasound system (Sonos 5500) capable of harmonic imaging. Intermittent imaging is performed with ultrasound transmitted at 1.8 MHz and received at 3.6 MHz. Once the systemic microbubble concentration reaches steady-state (1-1.5 min), intermittent imaging is begun, at pulse intervals ranging from 1 to 15 seconds, thus allowing progressively greater replenishment of the ultrasound beam elevation between destructive pulses. Three images are acquired at each pulse interval. Additional images are acquired with the same beam characteristics at a 30 Hz sampling rate, at which there is replenishment of microbubbles only in vessels with very rapid flow, and these were used as background images. Data are recorded digitally and analyzed using custom-designed software described elsewhere (25). Averaged background frames (acquired at a 30 Hz frame rate) are digitally subtracted from the averaged frames acquired at each pulsing interval. Mean video intensity in the region of interest is measured from the background-subtracted images. Pulsing interval vs. video intensity plots are generated and fitted to an exponential function: y=A(1-e □□t ). Where y is the video intensity at a pulsing interval t, A is the plateau video intensity representing microvascular blood volume, and □ is the rate constant reflecting the rate of rise of video intensity (and mean microbubble velocity, or microvascular flow velocity) (FIG. 7) (25,26). FIG. 7. This figure illustrates in more detail how the microvascular blood volume or capillary volume and microvascular flow velocity are determined using CEU. FIG. 7 a illustrates the successive filling of a capillary over time after all microbubbles in the capillary have been lysed by a high energy harmonic ultrasound pulse. As the delay time prior to signal detection increases (T0 through T5) the number of microbubbles and hence the videointensity increases. FIG. 7 b plots this data for typical signals collected over forearm muscle. The tangent to the upward sloping hyperbolic function is a measure of the rate of microvessel filling (MVFV) while the asymptote that intercepts the y-axis is a measure of the maximal signal seen when the vessels are filled and is determined by the microvascular volume (MW) i.e. capillary volume. In order to derive values for the MVFV and MW, the time versus video intensity plots are fitted to the function: Y=A(1-e −βt ), where Y is the video intensity at time t, A is the plateau intensity which represents MW, and p is the time constant of rise and reflects velocity. FIG. 7 c shows a typical experiment done before (open circles) and after (filled circles) infusing insulin (3 mU/min/kg) to an anesthetized rat. The plateau videointensity (A) is clearly higher, with no change in the rate of microvascular filling (β).
[0063] A positive effect of the drug would be seen as enhancing glucose uptake across the arm and enhanced capillary recruitment typified by an increase in the microvascular volume from CEU over insulin alone. As above, those drugs most useful in treating insulin resistance will be effective in insulin resistant subjects. A positive result in normal healthy individuals is not essential and probably not desirable.
[0064] Examples of Drugs Acting to Increase Capillary Recruitment Based on Mechanism.
[0065] These may act by inhibiting cyclic GMP degradation in those smooth muscle cells of the terminal arterioles controlling blood flow entry to the nutritive capillaries. As an example, the drug would be targeted to the specific isoenzyme form of cyclic GMP phosphodiesterase expressed in those same smooth muscle cells. The concept for this mechanism is analogous to that accounting for the action of Viagra®.
[0066] Alternatively, these drugs may act by altering gene expression over a period of time so that insulin's action to recruit capillary blood flow in muscle is enhanced. A mechanism envisaged here would encompass the induction of enzyme(s) responsible for the production of NO in endothelial cells of the terminal arterioles controlling blood flow entry to the nutritive capillary networks of muscle. Equally, repression of enzyme(s) responsible for NO destruction at these sites, is envisaged. Combined, or separate, such chronic effects of an administered drug would resemble the effects of exercise training as recently reported by us where both insulin-mediated capillary recruitment and muscle glucose uptake was increased (27).
[0067] Alternatively, these drugs may act by enhancing focal production of NO in the vicinity of the smooth muscle cells of the terminal arterioles controlling blood flow entry to the nutritive capillaries. The process of enhanced NO production is identical to that normally used by insulin. General or global production of NO in skeletal muscle is counter-productive and would very likely dilate arterioles controlling blood flow to the non-nutritive route.
[0068] As a further alternative, these drugs may act by enhancing the focal production of endogenous vasodilators from muscle glucose metabolism. As an example, adenosine is thought to be one of the vasodilators produced by exercising muscle and responsible for the reactive hyperaemia. A logical drug targeted at enhancing the effect of adenosine would act to block adenosine degradation; i.e. an inhibitor of adenosine deaminase.
[0069] As a further alternative, these drugs may act using site-specific delivery of a micro-encapsulated nitrovasodilator with the intention of releasing NO in the vicinity of the smooth muscle cells of the terminal arterioles controlling blood flow entry to the nutritive capillaries. There are several enzymes located in the aforementioned specific regions including angiotensin converting enzyme, alkaline phosphatase, and uridine diphosphatase that could be used to hydrolyse polymers constituting the micro-encapsulated nitrovasodilator.
[0070] As a further alternative, these drugs may act by blocking substance(s) in the blood that are preventing the normal effect of insulin to recruit capillary flow. For example, we have shown the inflammatory cytokine, TNFα to completely block insulin-mediated capillary recruitment and 50% of the insulin-mediated muscle glucose uptake. It follows that an agent that blocks TNFα would under these circumstances restore normal insulin responses.
[0071] Finally, these drugs may act through a central acting mechanism to modify vasomotor neural output thus increasing capillary recruitment by site-specific vasodilatation.
[0072] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.
[0073] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
REFERENCES
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[0075] 2. Baron A D, Steinberg H, Brechtel G, Johnson A: Skeletal muscle blood flow independently modulates insulin-mediated glucose uptake. Am J Physiol 266:E248-E253, 1994
[0076] 3. Baron A D: Insulin and the vasculature-old actors, new roles. J Investig. Med. 44:406A12, 1996
[0077] 4. Utriainen J, Malmstrom R, Makimattila S, Yki-Jarvinen H: Methodological aspects, dose-response characteristics and causes of interindividual variation in insulin stimulation of limb blood flow in normal subjects. Diabetologia 38:555-564, 1995
[0078] 5. Laine H, Yki-Jarvinen H, Kirvela O, Tolvanen J, Raitakari M, Solin O, Haaparanta M, Knnuti J, Nuutila P: Insulin resistance of glucose uptake in skeletal muscle cannot be ameliorated by enhancing endothelium-dependent blood flow in obesity. J. Clin. invest. 101: 1156-1162, 1998
[0079] 6. Yki-Jarvinen H, Utriainen T: Insulin-induced vasodilatation: physiology or pharmacology? Diabetologia 41:369-379, 1998
[0080] 7. Scherrer U, Randin D, Vollenweider P, Vollenweider L, Nicod, P: Nitric oxide release accounts for insulin's vascular effects in humans. J Clin. Invest. 94:2511-2515,1994
[0081] 8. Vollenweider L, Tappy L, Owlya R, Jequier E, Nicod P, Scherrer U: Insulin-induced sympathetic activation and vasodilation in skeletal muscle. Diabetes 44:641-645, 1995
[0082] 9. Natali A, Bonadonna R, Santoro D, Galvan A, Baldi S, Frascerra S, Palombo C, Ghione S, Ferrannini E. Insulin resistance and vasodilation in essential hypertension. J Clin Invest 94:1570-1576,1994
[0083] 10. Sarabi M, Lind L, Miligard J, Hanni A, Hagg A, Berne C, Lithell H: Local vasodilatation with metacholine, but not with nitroprusside, increases forearm glucose uptake. Physiol Res 48:291-295, 1999
[0084] 11. Jarasch E D, Bruder G, Heid H W: Significance of xanthine oxidase in capillary endothelial cells. Acta Physiol. Scand. Suppl. 548:39-46,1986.
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[0086] 13. Youd J M, Newman J M B, Clark M G, Appleby G J, Rattigan S, Tong A CY & Vincent M A. Increased metabolism of infused 1-methylxanthine by working muscle. Acta Physiol. Scand. 166: 301-308, 1999.
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[0088] 15. Rattigan S, Clark M G & Barrett E J. Acute vasoconstriction-induced insulin resistance in vivo in rat muscle. Diabetes, 48: 564-569,1999.
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[0098] 25. Wei K, Skyba D M, Firschke C, Jayaweera A R, Lindner J R, Kaul S. Interactions between microbubbles and ultrasound: in vitro and in vivo observations. Journal of the American College of Cardiology 29(5):1081-8,1997.
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[0100] 27. Rattigan S, Wallis M G, Youd J M & Clark M G. Exercise training improves insulin-mediated capillary recruitment in association with glucose uptake in rat hindlimb. Diabetes, 50: 2659-2665, 2001. | The present invention relates to methods and drugs for ameliorating insulin resistance in skeletal muscle, a major contributing abnormality to impaired glucose handling in such diseases as type 1 and type 2 diabetes, hypertension, obesity and critical care patients. This invention provides drugs, methods for screening those drugs and methods specifically targeted to ameliorating insulin resistance by increasing capillary blood flow in muscle. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for updating a geological reservoir model representative of the structure and of the behavior of a petroleum reservoir, by integration of dynamic data.
More particularly, the invention applies to the construction of a map associated with the geological reservoir model, representative of the static and dynamic petrophysical properties and of their spatial variabilities provides engineers a means allowing better estimation of the reserves of a petroleum reservoir and to optimize recovery by selecting a suitable production scheme.
2. Description of the Prior Art
Optimization and development of petroleum reservoirs is based on the most accurate possible description of the structure and of the behavior of the reservoir A tool is used which accounts for these two aspects in an approximate way: a geological reservoir model. A geological reservoir model best accounts for the structure and the behavior of the reservoir. The model includes a grid pattern that forms the frame of the reservoir and that has to be representative of the structure, and petrophysical property maps associated with this grid, that have to be representative of the behavior. This association assigns a petrophysical value obtained from maps to each grid cell of the model.
A petrophysical property map describes the spatial distribution or spatial structure, in an underground zone, of continuous or discrete petrophysical properties such as permeability, porosity, lithology type, . . . Conventionally, these maps are obtained from stochastic methods and are then referred to as stochastic models. In a stochastic context, the expression realization is used rather than numerical model.
The quality of the optimization and of the development of a petroleum reservoir thus directly depends on the accuracy of the stochastic realizations (petrophysical property maps). It is therefore advisable to work out stochastic realizations and therefore, more generally, reservoir models that are as coherent as possible with all the data collected (well, seismic, laboratory data, . . . ).
The data available for constraining stochastic realizations are referred to as static or dynamic. A datum is static if it corresponds to a measurement of the property modelled at a given point and if it is independent of time. Permeability measurements performed in the laboratory on rock samples or logs measured along wells are static data. A datum is dynamic if it depends on time, it is linked with the property modelled without being a direct measurement thereof. Production data and 4D seismic data, that vary with fluid flows, are dynamic data. Since the data are insufficient to allow deterministic description of the spatial distribution of the property considered, stochastic modelling techniques are most often based on geostatistical techniques, which provide a family of numerical stochastic models associated with the geological reservoir model and referred to as realizations.
In a stochastic context, data describing the geology of the medium define a random function. For a single random function, there is an infinity of possible realizations. All these realizations are however not compatible with dynamic data.
Static and dynamic data are not integrated in the same way in the stochastic realization. Integration of static data is carried out upon generation of the realization whereas integration of dynamic data goes through the solution of an inverse problem involving a flow simulator. Dealing with the inverse problem first requires defining a function referred to as objective function, or cost function, that measures the relevance of the realization or of the reservoir model proposed. In the first research work devoted to this subject, the objective function was a direct measurement of the difference between the dynamic data collected in the field and the corresponding responses obtained by simulation:
J ( y ) = ∑ i w i ( d sim i - d obs i ) 2
y is the realization considered and J(y) the value of the objective function for this realization. The w are weighting coefficients. The d obs are the dynamic data collected and the d sim are the simulated corresponding responses. The quantity g is the operator that goes from the space of the non-constrained realizations to the space of the dynamic data: d sim =g(y). Minimizing this objective function leads to determination of a realization y that reproduces all of the dynamic data as well as possible. Unfortunately, the spatial structure of realization y thus obtained is generally no longer coherent with that of the initial realization, that is with the geologic data.
A framework more suited to the definition of the objective function is provided by the Bayesian approach. A priori information is then added to the objective function. This approach is described in the document as follows:
Tarantola, A., 1987, “ Inverse Problem Theory—Methods for Data Fitting and Model Parameter Estimation”., Elsevier, Amsterdam, 613 p.
The objective function is then expressed as follows:
J
(
y
)
=
1
2
(
g
(
y
)
-
d
obs
)
t
C
D
-
1
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g
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y
)
-
d
obs
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1
2
(
y
-
y
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t
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Y
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1
(
y
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The first term of the objective function deals with the likelihood constraint: it measures the difference between the dynamic data observed in the field and the equivalent data obtained by numerical simulation. The second term corresponds to the a priori constraint: it quantifies the difference between the a priori reservoir model y o , deduced from the a priori geologic information, and the proposed reservoir model y. The covariance matrix C D characterizes the experimental and theoretical uncertainties, whereas C y concerns the uncertainty on the a priori model. Minimization of the objective function then provides a model y that is as close as possible to the a priori model and such that data d sim simulated for this model are close to the data measured in the field.
Calculation of the objective function can be difficult, notably on account of the two covariance matrices that have to be inverted. In general, the covariance matrix relative to the data is assumed to be diagonal and it is readily inverted. This hypothesis is most certainly questionable depending on the case considered, for example with the 4D seismic method, but it is not challenged here. The case of the covariance matrix relative to model y is more awkward. In fact, the dimension of a priori covariance matrix C y is the length of the vector y and calculation of its inverse is often impossible for models comprising a very large number of grid cells. To date, to simplify taking account of the a priori constraint, essentially three types of approach have been developed. The first type of approach is based on the division of covariance matrix C y into subspaces: the least influent components are disregarded, which allows the number of variables to be reduced. This technique is described in the document as follows:
Reynolds, A. C., He, N., Chu, L., and Oliver, D. S., 1995 , “Reparameterization Techniques for Generating Reservoir Descriptions Conditioned to Variograms and Well-Test Pressure Data .”, SPE Annual Technical Conference and Exhibition, Dallas, Tex., 22-25 October, SPE 30588, p. 609 -624.
The second type of approach is based on the mathematical modelling of errors in the parameters space by a Gaussian random function of mean zero and of exponential covariance along preferred directions. There are thus mathematical properties allowing to analytically calculate the inverse of the a priori covariance matrix. This method is described, for example, in French Patent 2,635,197 and corresponding U.S. Pat. No. 4,972,383.
Finally, the third type of approach involves geostatistical parameterization, with in particular the pilot point method introduced in the document as follows:
Marsily, G. de, 1978, “De I'identification desSystémes Hydrologiques”., Thése de Doctorat d'Etat, Université Paris VI, France.
and the gradual deformation method described in the document as follows:
Hu, L. Y., 2000, “Gradual Deformation and Iterative Calibration of Gaussian-Related Stochastic Models.”, Math. Geology, v. 32, no. 1, p. 87-108.
The pilot point method was first introduced within the context of estimation prior to being extended to the conditioning of stochastic realizations by dynamic data by:
RamaRao, B. S., LaVenue, A. M., de Marsilly, G., and Marietta, M. G., 1995, “Pilot Point Methodology for Automated Calibration of an Ensemble of Conditionally Simulated Transmissivity Fields. 1. Theory and Computational Experiments.”, Water Res. Res., 31(3), 475-493.
This technique allows local deformation of realizations from a reduced number of parameters while respecting the spatial variability of the property modelled (permeability, porosity, velocity, . . . ). In short, in order to modify the realization, a set of points (or cells) referred to as pilot points, whose values can be changed, is selected. The perturbation generated at these points spreads over the entire realization by kriging according to the expression:
y x ( x )= y dK ( x )+[ y ( x )− y k ( x )]
y is a non-constrained realization. The quantity y dK results from kriging of the static data and the values of the pilot points, and y K from kriging of the values of y at the same points. The quantity y c is a constrained realization that honors the spatial variability model and the values of the static data, as well as the values selected for the pilot points. In other words, the pilot points are regarded as static data that are used to constrain the realization. The values of the pilot points are the parameters of the optimization problem. These “pseudo”-data, unlike the real static data, are not stationary: they can vary during the optimization procedure so as to reduce the objective function. Since the modifications are propagated to the entire realization by kriging, conservation of the spatial variability model is ensured. Adding the term relative to the a priori constraint in the objective function is therefore considered to be redundant. This objective function then comes down to the single term measuring the difference between the real dynamic data and the corresponding responses obtained by simulation. It is no longer necessary to determine the inverse of the a priori covariance matrix. This property is fundamental and characteristic of the pilot point method.
However, the pilot point method can involve numerical artifacts. In some cases, minimization of the objective function goes through the assignment of extreme values to the pilot points. We can then have either too high values or too low values, which no longer make sense, physically speaking. To avoid these artifacts, constraints by inequalities can be integrated in the optimization procedure: the variations of the parameters are then bounded. This technique is described more precisely in the aforementioned document by RamaRao et al. (1995). Besides, the values of the pilot points are adjusted independently of one another. The pilot points therefore have to be separated by a distance that is greater than or equal to the correlation length. If this minimum distance is not respected, the pilot point method does not guarantee preservation of the spatial variability model.
The gradual deformation method was initially proposed to continuously modify Gaussian stochastic processes (random processes). It is a geostatistical parameterization technique allowing deformation of a realization of a reservoir, model comprising any number of grid cells from a reduced number of parameters, while respecting the spatial variability model. The basic idea is that the sum of Gaussian random functions is a Gaussian random function.
The simplest gradual deformation scheme adds up two multi-Gaussian random functions. Let Y 1 and Y 2 be two such functions, independent and stationary of order 2. They are also assumed to have the same mean (y o ), variance and covariance model. A new random function Y(t) is constructed by combining Y 1 and Y 2 according to the expression as follows:
Y ( t )−y o =└Y 1 −y o ┘cos( t )+└ Y 2 −y O ┘sin( t )
It can be shown that, for any deformation coefficient t, Y has the same mean, variance and spatial variability model as Y 1 and Y 2 . In fact, the sum of the coefficients squared, i.e. cos 2 (t)+sin 2 (t), is 1. According to this combination principle, construction, from two realizations independent of Y 1 and Y 2 , denoted by y 1 and y 2 , of a chain of realizations depending only on deformation parameter t is possible.
y ( t )− y o =└y 1 −y o ┘cos( t )+└ y 2 −y o ┘sin( t )
This chain of realizations goes through y 1 and y 2 . When t is 0, y is y 1 . When t is □/2, y is y 2 . By continuously varying the deformation coefficient t from 0, continuous deformation of realization y 1 is simulated. By varying continuously deformation coefficient t from 0, continuous deformation of realization y 1 , taken as the initial realization, is simulated. An essential point is that, for any value of t, realization y is multi-Gaussian and respects the mean, variance and spatial variability model of y 1 and y 2 .
When the gradual deformation method is integrated in an optimization process as a parameterization technique, the objective function to be minimized becomes:
J
(
t
)
=
1
2
[
g
(
t
)
-
d
obs
]
t
C
D
-
1
[
g
(
t
)
-
d
obs
]
.
In fact, as for the pilot point method, it seems redundant to add the a priori constraint in the objective function because parameterization intrinsically preserves the spatial variability model. Vector t combines the various deformation coefficients. These coefficients are the parameters of the optimization problem. These deformation parameters have to be identified so as to reduce the objective function as much as possible.
The gradual deformation method as presented here implies that the entire realization is deformed to minimize the objective function. However, the gradual deformation method can also be applied locally. In this case, instead of combining realizations with a given spatial variability model, the Gaussian white noises used to generate these structured realizations are combined. More precisely, when the deformation is to be located in a given zone, the components (random numbers) of the Gaussian white noise assigned to the cells included in the zone to be deformed are gradually deformed. This technique is described in the document as follows:
Le Ravalec, M., Noetinger, B., and Hu, L.-Y., 2000, “The FFT Moving Average (FFT-MA)Generator: An Efficient Numerical Method for Generating and Conditioning Gaussian Simulations.”, Math. Geol., 32(6), 701-723.
If necessary, the gradual deformation method can be applied to an isolated component of the Gaussian white noise. It then tends towards the pilot point method. An important difference has to be noted: the gradual deformation method prevents the modified point from taking extreme values. Furthermore, if several points are modified according to the gradual deformation method, the spatial correlations between the deformed points are taken into account. However, the gradual deformation method is negligible when it is applied to points. An optimization procedure involving this type of parameterization will therefore probably be much less efficient than the pilot point method.
SUMMARY OF THE INVENTION
The method according to the invention allows local deformation of a realization significantly while preserving the spatial variability model.
The invention relates to a method for updating a geological reservoir model representative of the behavior of a heterogeneous porous medium and discretized in space into a set of cells forming a grid representative of the structure of the medium, allowing accounting for the dynamic data (DD) acquired by measurements and varying in the course of time according to fluid flows in the medium, the method comprising:
A) constructing an initial map (y) of petrophysical properties by means of a geostatistical simulator and of static data (SD);
B) integrating the dynamic data (DD) by optimizing the initial map by:
a) constructing an initial set of gradual pilot points (PP i ); b) constructing at least one complementary set of gradual pilot points (PP c ); c) constructing a combined set of gradual pilot points (PP(t)) by combining the sets of gradual pilot points (PP i and PP c ) according to the gradual deformation method wherein at least one deformation parameter is a characteristic parameter of said pilot points; d) modifying the values of the petrophysical properties of the initial map (y) by constraining it by the combined set of gradual pilot points (PP(t)) and by the static data (SD); e) modifying the combined set (PP(t)) and resuming from c) until a stop criterion is reached; and
C) updating the geological reservoir model by associating the map optimized in B) with the grid of the model.
The initial and complementary sets of gradual pilot points can be constructed by means of random generations using distribution laws deduced from the values of the static data (SD).
The characteristic parameters of a pilot point can be selected from among the following parameters: its position and its associated petrophysical property value.
According to the invention, a flow simulator can be used to estimate dynamic data simulated from the petrophysical property values of the modified initial map (y). It is thus possible to compare, by means of an objective function, the simulated dynamic data and the dynamic data acquired by measurements, in order to modify the combined set and to define the stop criterion. In this embodiment, as long as the objective function is greater than a given threshold, if it does not converge, the deformation parameter can be modified and optimization can be continued in c) and, if it converges, the initial set of gradual pilot points (PP i ) can be replaced by the combined set of gradual pilot points (PP(t)), and the procedure can be repeated from b).
The static data can be logs and/or measurements on samples taken in wells and/or seismic data, and the dynamic data can be production data and/or well tests data and/or breakthrough time data.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the method according to the invention will be clear from reading the description hereafter of embodiments given by way of non limitative example, with reference to the accompanying figures wherein:
FIG. 1 diagrammatically shows the method according to the invention with deformation of a single parameter;
FIG. 2 diagrammatically shows the method according to the invention with deformation of several parameters;
FIG. 3 shows a reference permeability field and flow lines. The positions where permeability values are known are shown by circles with superposed crosses;
FIG. 4 illustrates a distribution function (CDF) of the times (T) taken by the particles to run through the medium;
FIG. 5A shows an initial realization;
FIG. 5B shows a realization constrained by the dynamic data from the pilot point method;
FIG. 5C shows a realization constrained by the dynamic data from the global gradual deformation method; and
FIG. 5D shows a realization constrained by the dynamic data from the gradual pilot point method. The position of the pilot points is shown by a square with a superposed cross.
DETAILED DESCRIPTION OF THE INVENTION
The method according to the invention updates a geological reservoir model representative of the structure and of the behavior of a heterogeneous porous medium, by integration of dynamic data. More particularly, the invention applies to the construction of a map associated with a geological reservoir model, representative of the static petrophysical properties and of the spatial variabilities thereof, coherent with the dynamic data collected in the field, such as production data or 4D seismic data.
A geological reservoir model has a grid discretizing the structure of a heterogeneous porous medium and of at least one map of petrophysical properties representative of the of this medium. A map is made up of a grid which is not necessarily the same as the grid of the geological reservoir model, each cell of which is associated with a petrophysical value. All of these values, connected by spatial relations, form a “realization”. This term is used because the petrophysical property is considered to be a random variable. Various realizations of this random variable provide as many petrophysical property maps.
According to the invention, construction of such maps comprises three main stages:
Stage E 1
First of all, static data (SD) such as logs, measurements on samples taken in wells, seismic data are measured in the field on the one hand and, on the other hand, dynamic data (DD) such as production data, well test data or breakthrough time data whose specific feature is to vary in the course of time according to fluid flows in the reservoir are collected in the field.
The spatial variabilities thereof are then analyzed by means of techniques known to specialists, such as variographic analysis. The general flowsheet of the method according to the invention is shown in FIG. 1 .
Stage E 2
Then, from the static data, a random function characterized by its covariance function (or similarly by its variogram), its variance and its mean is defined by means of known data analysis techniques.
Furthermore, a grid pattern and a set of random numbers drawn independently of one another are defined for each map: it can be, for example, a Gaussian white noise or uniform numbers. There is therefore an independent random number for each grid cell and for each map.
Finally, from a selected geostatistical simulator and from the set of random numbers, a random draw is carried out in the random function, which leads to a realization, continuous or discrete, representing a possible image of the petrophysical properties of the reservoir.
The associated random realization is denoted by y. It is constrained neither by the static data (SD) nor by the dynamic data (DD).
Stage E 3
At this stage, the dynamic data have not been considered. They are integrated in the geological reservoir models by means of an optimization or of a calibration of the maps. An objective function measuring the difference between the dynamic data measured in the field and the corresponding responses simulated for the realization considered is defined. The goal of the optimization procedure is to gradually modify this map so as to reduce the objective function. In the end, the modified maps are coherent in relation to the static data and to the dynamic data.
This stage of the method according to the invention can be referred to as “gradual pilot point method” because it is based on an integration of the pilot point method (Marsily, G., 1978) and of the gradual deformation method (Hu, L. Y., 2000). In fact, it allows modification of a realization locally and significantly like the pilot point technique while preserving the spatial variability model like the gradual deformation technique. In this context, “gradual pilot points” are pilot points to which a gradual deformation technique is applied.
This stage comprises the following stages E 4 to E 12 .
Stages E 4 and E 4 ′
In parallel with the generation of a realization y, an initial set of gradual pilot points denoted by PP i (stage E 4 ) and at least one complementary set of gradual pilot points denoted by PP c (stage E 4 ′) are constructed.
The position on the map of each point is first defined. Sensitivity studies can be envisaged from gradient calculations so as to best position the pilot points on the map. It is also possible to position these points in zones where a deformation is to be provided on the map. For example, when 4D seismic data are to be integrated, it is judicious to position the points at the level of the interfaces between the fluids saturating the reservoir.
Then a petrophysical property value is associated with each pilot point. For the complementary set, an initial set of values is generated randomly and independently by following the same random function as the one used to generate y. This initial set then forms a realization. This realization associated with the complementary set of gradual pilot points can for example be produced from Cholesky's method. This method is for example described in the document as follows:
Chilés, J. P., Delfiner, P., 1999, “Geostatistics—Modeling Spatial Uncertainty, Wiley Series in Probability and Statistics”, New York, USA.
Cholesky's method allows generation of multi-Gaussian realizations at points unevenly distributed in space. It is appropriate as long as the number of points is small. Beyond 1000 points, another simulation method such as the turning band method, the Gaussian sequential simulation method or the FFTMA method is preferably used.
The same methods can be used for the initial set, but it is also possible to directly use the values of initial map y.
Stage E 5
Gradual pilot points PP i and PP c are then combined according to the gradual deformation method to produce a set of gradual pilot points PP(t). The basic scheme combines two sets of gradual pilot points according to the expression:
y P ( t )− y o =└y P 1 −y o ┘cos( t )+└ y P 2 −y o ┘sin( t )
The quantities y P 1 and y P 2 are the two sets of gradual pilot points brought back by anamorphosis, if necessary, to a normal base. In this context, the inversion parameters are checked to not be the values of the gradual pilot points themselves, but the deformation coefficient t. This formulation reduced here to the combination of two sets of gradual pilot points can be extended to the combination of N sets of gradual pilot points. In the latter case, the number of deformation parameters is brought to N-1 as shown in the document as follows:
Roggero, F., and Hu, L.-Y., 1998 , “Gradual Deformation of Continuous Geostatistical Models for History Matching ”, SPE ATCE, 49004, New Orleans, La., USA.
The interest of combining a large number of sets of gradual pilot points is that it provides more flexibility for the optimization procedure. It is in fact easier to reduce an objective function where there are several levers for exploring the space of the sets of gradual pilot points.
The deformation parameters simultaneously affect all of the gradual pilot points. In this case, the gradual deformation is referred to as global and the spatial correlations between the pilot points are taken into account. In other words, the gradual pilot points obtained PP(t) honor the spatial variability model for any value of the deformation parameters (t).
Stage E 6
After the gradual combination stage, the kriging technique is used (stage E 6 ) to constrain realization y previously generated in stage E 2 , by the static data on the one hand (SD), and the set of pilot points from gradual deformation PP(t) on the other hand:
y csd ( u )= y dK ( u )+[ y ( u )− y K ( u )]
The quantity y is the initial realization from stage E 2 , y dK is the estimation of the kriging of the static data available and of the gradual pilot points, and y K is the estimation of the kriging of the values of y at the location of the measurements and of the pilot plants, the quantity y csd is the realization constrained by the static data (SD).
Stage E 7
Carrying out a flow simulation FS for this constrained realization y csd allows a set of dynamic data to be calculated.
Stage E 8
An objective function F (stage E 8 ) is calculated from the dynamic data calculated in stage E 7 and the measured dynamic data. This objective function measures the difference between the simulated data and the measured real data.
Stage E 9
The value of the objective function is compared with a fixed threshold ε. The quantity ε is a real number close to zero. If objective function F is small enough, that is, if F is less than the fixed value ε, the minimum seeking procedure stops (STOP). In the opposite case, two situations can be considered.
Stage E 10
These two situations depend on the convergence of objective function F. Thus, in stage E 10 , it is determined if the objective function converges towards a plateau value denoted by P or not. Thus, according to the convergence (C) or not of objective function F, stage E 11 or stage E 12 is carried out:
Stage E 11
If the objective function has not converged, the optimization O in progress is continued by varying the deformation parameters. The parameters of the successive optimizations O are the deformation parameters. Their number is equal to the number of sets of complementary pilot points. The number of parameters can thus be greatly reduced.
Stage E 12
Although the objective function F is still great (greater than ε), it has converged towards a plateau P. The deformation parameters such as parameter t determined so far are considered to be optimum parameters and they are used to update the initial set of initial gradual pilot points PP i . Then a new complementary set of pilot points PP c is drawn at random (stage E 4 ′). A new optimization O of the deformation parameters is then launched (stages E 5 to E 11 ).
Since the deformation of the gradual pilot points is global, that is the pilot points are simultaneously modified from the same deformation parameters, the deformed pilot points honour the spatial variability model. This property is important. It allows positioning of the gradual pilot points as one wishes to on the realization. It is not necessary to respect a minimum distance between these points.
In short, the parameters adjusted to minimize the objective function are the deformation parameters ensuring combination of the pilot points rather than the values of the pilot points themselves. In other words, the values of the pilot points are no longer directly governed by the optimizer. The gradual deformation method is used as an intermediary between the pilot points and the optimizer. Thus, during the optimization procedure, the optimizer modifies the gradual deformation coefficients which control the values of the pilot points.
Second Embodiment
According to a second embodiment, the method according to the invention can be extended by integrating in the objective function a gradual deformation parameter (p) controlling the position of the gradual pilot points. The position of the gradual pilot points is modified by varying this parameter.
In this embodiment, not only the values of the two sets of initial gradual pilot points (PP i and PP c ), but also their positions are considered. These positions correspond to uniform numbers that are converted to Gaussian numbers:
Y=G −1 ( x )
where G is the standard normal distribution function, x is the position vector of the pilot point and Y is its associate in the standard normal base. Two possible positions x 1 and x 2 of pilot points can be gradually combined according to the expression:
x ( p )= G[G −1 ( x 1 )cos( p )+ G −1 ( x 2 )sin( p )]
The quantity p is the deformation parameter. Variation of the deformation parameter modifies the position of the pilot point. This method was introduced in the document as follows:
Hu, L.-Y., 2000, Geostats 2000 Cape Town, W J Kleingeld and D G Krige (eds.), 1, 94-103.
Thus, during the optimization procedure, one can try to estimate optimum deformation parameter p, that is the position of the pilot points, by reducing the objective function as much as possible.
Other Embodiment
It is also possible, according to another embodiment of the invention, to try to simultaneously estimate optimum deformation parameters p and t as illustrated in FIG. 2 .
APPLICATION EXAMPLE
The following example illustrates the efficiency of the method developed. This example is limited to the deformation of the pilot point values (deformation parameter t, FIG. 1 ). FIG. 3 shows a synthetic permeability map (field) k discretized with a 30-cell grid in direction X and 20 cells in direction Z. The size of the cell is 1 m×1 m. The distribution is lognormal; the mean and the variance of In(k) are 3 and 1 respectively. The spatial variability of In(k) is apprehended by a spherical isotropic variogram of correlation length 10 m. For this reference synthetic map, a tracer injection experiment is numerically simulated: inert particles are injected on the left side of the map and produced on the right side. The dynamic data is obtained referred to as reference data, which are the distribution function (CDF) of the times (T) taken by the particles injected to flow through the medium, as illustrated in FIG. 4 , where the time T is given in days. The reference permeability map is now assumed not to be known. The only available information for characterizing the permeability map is given by the mean, the variance, the spatial variability model, the permeability measured at five points identified by circles on which crosses are superposed, and the distribution function of the travel times. The permeability map shown in FIG. 5A is now considered as the initial point of the investigation process. This map is coherent in relation to the statistical properties and the five permeability measurements, but not in relation to the travel times. It therefore has to be deformed to ensure also reproduction of the travel times. The pilot point method, the gradual deformation method and the method according to the invention (gradual pilot point method) are then applied to improve calibration of the travel times. Every time, the start point is from the same initial point. The permeability maps obtained at the end of the calibration, that is at the end of the optimization procedure, are shown in FIGS. 5B , 5 C and 5 D for each method. For the pilot point method ( FIG. 5B ), 6 pilot points are positioned; they are symbolized by squares with superposed crosses. It can be recalled that the pilot points must be separated by at least a correlation length, which limits the number of possible points. It can be seen that the constrained permeability map has been essentially modified at the top ( FIG. 5B ). Besides, within the context of the pilot point method, there is one parameter per pilot point. Six parameters are thus used here. For the gradual deformation method ( FIG. 5C ) and the method according to the invention ( FIG. 5D ), a single parameter is considered. The entire permeability map was modified during the optimization procedure. For the gradual deformation method ( FIG. 5C ), this result is natural because the deformation was of global type. For the method according to the invention ( FIG. 5D ), taking account of the spatial correlations between gradual pilot points allows positioning of as many such points as desired on the permeability map. Finally, the efficiency of the deformation techniques used is evaluated in terms of number of flow simulations for reducing the objective function by 95% (Table 1). The objective function is defined here as the difference squared between the simulated travel times and the reference travel times. For the pilot point method, the case studied requires carrying out about a hundred flow simulations to reduce the objective function by 95%. In parallel, the gradual deformation method involves carrying out about fifty flow simulations whereas the method according to the invention only requires about 20 such simulations.
TABLE 1
Number of flow simulations carried out to reduce the objective
function by 95%
Deformation method
Number of flow simulations
Pilot points
100
Gradual deformation
50
Gradual pilot points
20
The method according to the invention thus allows updating a geological reservoir model representative of the structure and of the behaviour of a heterogeneous porous medium, by integrating static and dynamic petrophysical properties in the definition of the associated maps. The method comprises parameterization which allows dynamic data to be integrated by deforming locally and efficiently an initial map so as to make it coherent in relation to a set of dynamic data while preserving the spatial structure of the realization. The spatial correlations between the gradual pilot points are taken into account. It is thus possible to position as many pilot points as desired on a petrophysical property map; it is not necessary to respect a minimum distance between the points. Furthermore, this method does not require constraining the values of the pilot points by inequalities.
Finally, the objective function variations are controlled from a small number of parameters (the number of parameters is not the number of pilot points). If necessary, the objective function is minimized by adjusting a single deformation parameter.
The method thus provides engineers with means for integrating dynamic data in order to predict the dynamic behavior of a petroleum reservoir. | A method for updating a geological reservoir model by integration of dynamic data having application, for example, to petroleum reservoir development. An initial map (y) of petrophysical properties is constructed by means of a geostatistical simulator and of static data. Then an initial set of gradual pilot points (PP i ) and at least one complementary set of gradual pilot points (PP c ) are constructed. A combined set of gradual pilot points (PP(t)) is then constructed by combining these sets of gradual pilot points according to the gradual deformation method wherein at least one deformation parameter is a characteristic parameter of said pilot points (position and/or value). The initial map (y) is then modified, the deformation parameters are modified according to the dynamic data and the procedure is repeated until a stop criterion is reached and the geological reservoir model is updated by associating the map thus optimized with the grid of the model. | 6 |
[0001] This application is a continuation-in-part of U.S. Ser. No. 08/787,967, filed Jan. 23, 1997.
BACKGROUND OF THE INVENTION
[0002] The subject invention is directed toward the art of tube fittings and, more particularly, to an improved phase controlled, sequential gripping tube fitting.
[0003] The general form of tube fitting with which this invention is concerned is described and claimed in the following series of U.S. Pat. Nos. which are incorporated herein by reference:
[0004] 2,484,815 issued Oct. 18, 1949
[0005] 3,075,793 issued Jun. 29, 1963
[0006] 3,103,373 issued Sep. 10, 1963
[0007] 4,826,218 issued May 2, 1989
[0008] 4,915,427 issued Apr. 10, 1990
[0009] U.S. Pat. No. 4,915,427 discloses and claims a phase controlled, sequential gripping tube fitting particularly suitable for use on heavy walled tubes. The arrangement disclosed in the patent obtains proper pull-up action in a two ferrule fitting for heavy walled tubes by using ferrules having a relatively heavy and substantial construction including heavily flanged rear end portions. In addition, the coupling nut portion surrounding the ferrules is arranged to closely enclose the flanged rear end portions of the ferrules.
[0010] While the described arrangement works very satisfactorily, it would be more desirable to obtain equivalent functioning with lighter weight ferrules without relying on the heavy rear flange design.
SUMMARY OF THE INVENTION
[0011] The subject invention provides an arrangement which overcomes the above-discussed disadvantage of the prior design and allows relatively light weight ferrules to perform satisfactorily with heavy walled tubing by controlling and containing the ferrule swaging action in a manner which prevents undesirable ferrule deformation. The design prevents excessive “bear claw” deformation of the rear ferrule and assures that the rear ferrule transmits the necessary driving forces to the front ferrule prior to full engagement of the rear ferrule with the tube.
[0012] In accordance with a preferred form of the invention, a phase controlled, sequential gripping tube fitting including a main body having a cylindrical tube end receiving opening with a tapered camming mouth forming the entry to the opening has a front ferrule with a tapered forward nose surface in engagement in the camming mouth and a rear surface with a conically tapered recess that extends forwardly toward the nose surface. A rear ferrule having a conically tapered nose is positioned so that the tapered nose extends into the conically tapered recess of the front ferrule. The rear ferrule further includes a rear force engaging surface. Threadedly connected to the main body is a coupling nut engaged with the rear force receiving surface of the rear ferrule to drive the rear ferrule axially forward into the conically tapered rear surface of the front ferrule and produce radial inward movement of the nose portion of the rear ferrule as well as radial inward movement of the nose portion of the front ferrule. The assembly includes an improved arrangement to control outward buckling of the rear ferrule. The arrangement includes a cylindrical central body on the rear ferrule with the central body located between the nose portion and the rear force receiving surface. Associated with the central body is a cylindrical flange portion formed on the front ferrule and extending axially rearwardly therefrom at a location radially outward of the rear recess of the front ferrule. The cylindrical flange has a cylindrical interior surface that closely surrounds the cylindrical central body of the rear ferrule to limit radial outward movement of the rear ferrule or portions thereof.
[0013] The arrangement between the nose and central body of the rear ferrule and its relationship to the axially rearward extending cylindrical flange on the front ferrule results in containment of the rear ferrule and anchors it against toroidal torsion which can produce the “bear claw” deformation. In addition, it is believed that by moving the contact and force transmission point forwardly into the body of the front ferrule, the front ferrule is driven move smoothly and with less radial deformation. This result can be further enhanced by closely containing the rear portion of the front ferrule by providing the coupling nut with an interior cylindrical surface which substantially engages and closely contains the front ferrule against outward radial deflection.
[0014] A principal object and primarily advantage of the invention is that it allows the use of lighter weight ferrules than was previously possible when engaging heavy weight tubing.
[0015] A further object of the invention is the provision of an arrangement for use in a phase controlled, sequential gripping tube fitting to eliminate undesired torsional rotation in the rear ferrule even when a relatively light weight ferrule is used.
[0016] Yet another object of the invention is the provision of a phase controlled sequential gripping tube fitting that is especially suited for heavy walled tubing but which can also be used for standard weight tubing.
[0017] Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment and method of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
[0019] [0019]FIG. 1 is a partial side elevational view in cross section of a coupling device which employs a female coupling nut;
[0020] [0020]FIG. 2 is a view similar to FIG. 1 with a tube member inserted into the coupling and the coupling components made up to a finger-tight relationship;
[0021] [0021]FIG. 3 is a view like FIG. 1 but showing the fitting in its made up condition with the ferrules in their tube gripping positions; and,
[0022] [0022]FIG. 4 is a greatly enlarged view of the circled portion of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring now to the drawings wherein the showings are for the purposes of illustrating the preferred embodiment of the invention only and not for purposes of limiting same, the FIGS. 2 and 3 generally show a coupling body 10 with a tubular member 12 associated therewith and received therein. Suitable gripping and sealing engagement between the body 10 and the tube member 12 is achieved through the use of a coupling nut 14 and a ferrule arrangement 16 .
[0024] In the subject arrangement, the coupling body 10 has a first end 20 and an associated second end (not shown). It should be understood that the coupling body could be associated with any type of second end or associated structure and could be formed directly on a fluid flow device, such as a valve or the like. As can be appreciated, however, the coupling body 10 includes an internal flow passage 22 that joins with a cylindrical bore 24 extending axially inward of the first end 20 . The bore 24 is preferably coaxial with the internal flow passage 22 and the juncture between bore 24 and flow passage 22 provides a radial end wall or shoulder 26 . The diameter of counterbore 24 is, as can be seen from FIGS. 2 and 3, sized so as to closely but slidably receive the end of the tube 12 . The shoulder 26 provides an inward limit stop for the tube 12 and locates the tube end relative to the ferrule arrangement 16 . An outer counterbore 28 extends from counterbore 24 to the outer end of the fitting body and has a generally conical shape expanding radially outwardly to define a tapered, conical camming mouth about the bore 24 .
[0025] The coupling nut 14 is preferably of hex-shaped exterior configuration and has a central bore that is threaded as illustrated at 30 and cooperates with external threads 32 formed about the exterior of the body 10 on the first end 20 . The coupling nut 14 acts to drive the ferrule arrangement 16 into its sealed and gripping relationship in a manner subsequently to be described. For the present, it should be noted that the axial outer end of the coupling nut 14 includes a central bore 34 that is sized so as to closely encircle the exterior of the tube 12 . Referring in particular to FIGS. 1 and 4, the details and preferred construction for the ferrule arrangement 16 can best be understood. In particular, the assembly includes a front ferrule 36 and a rear ferrule 38 . The front ferrule 36 has a central through opening 40 which is cylindrical in shape and sized so as to closely but slidably receive the tube 12 . The exterior of the ferrule 36 is of tapered configuration as shown and tapers at an angle α only slightly less than the taper angle of the camming mouth 28 . Preferably the angle α is in the range of about 10° to 30°. The corresponding angle of the camming mouth is generally slightly greater, as shown. The tapered outer surface 42 extends substantially the length of the ferrule from the nose 44 to adjacent the rear surface of the ferrule. The rear surface of the front ferrule 36 includes a conically tapered rear force receiving surface 46 that is inclined or tapered at an angle in the range of, for example, about 40° to 50° generally as shown.
[0026] Cooperating with the front ferrule is the second or rear ferrule 38 which has a central through opening 50 that generally corresponds in diameter to the central through opening 40 of the front ferrule 36 . This opening 50 is also arranged so as to closely but slidably receive the tube 12 . The forward or axial inner end 52 of the rear ferrule 38 is tapered so as to generally correspond to the taper of the force receiving recess 46 of the front ferrule. The rear ferrule 38 is preferably a unitary, annular ferrule, and does not have a split or a gap formed therein. Axially rearward of the inner or nose end 52 of ferrule 36 is a central body section 54 of cylindrical configuration. The axial outermost or right-hand end of the ferrule 38 is of slightly greater diameter as seen at 56 to define a radially extending end flange having a cylindrical radial outer side face 57 . A counterbore 58 within the coupling nut 14 is sized and arranged so as to enclose the flange defined by portion 56 of ferrule 38 . In addition, a slightly tapered or inclined end wall 60 on ferrule 38 is arranged to correspond with the angled inner shoulder 62 of the nut 14 and act as a force receiving surface when the nut 14 is tightened to body 10 to move the ferrules to their tube gripping and sealing position shown in FIG. 3.
[0027] Of particular importance to the invention is the relationship between the rear of the front ferrule and the forward, cylindrical body portion 54 of the rear ferrule 38 . In particular, it will be seen that the front ferrule 36 includes an axially rearwardly extending cylindrical flange portion 66 that defines a cylindrical bore 68 leading to the force receiving inclined surface 46 . This flange portion 66 preferably extends along a significant length of the rear ferrule, or the cylindrical body portion 54 , to radially constrain the rear ferrule. The flange portion 66 may extend less than half along the cylindrical body portion. However, other lengths of the flange 66 , such as greater than half the length of the cylindrical body portion, or about one fourth of the length of the rear ferrule 54 , or other varying lengths, may still be utilized. The flange portion 66 preferably has a thickness sufficient to prevent buckling of the central body portion 54 . Accordingly, the flange portion 66 is preferably thicker than the body portion 54 to prevent outward buckling of the central body portion, and in one embodiment the central body 54 is less than about two-thirds of the thickness of the flange portion 66 . As can be seen in FIG. 4, the outer diameter of the flange portion of the front ferrule 36 is radially outward of the rear ferrule. Thus in the illustrated embodiment the front ferrule 36 has an outer diameter greater than the rear ferrule 34 .
[0028] As best shown in FIG. 4, the flange portion 66 of the front ferrule 36 is radially spaced from the central body portion 54 of the rear ferrule 38 . A ferrule gap 77 is located therebetween. The ferrule gap 77 helps to prevent frictional forces and stresses from building up between the flange portion and the central body portion during makeup of the fitting. This enables the ferrules to slide relatively smoothly during make-up. Although the nose 52 of the rear ferrule 38 engages the force receiving surface 46 of the front ferrule 36 during make up, the spacing between the ferrules at the ferrule gap 77 is preferably maintained during makeup. If there is buckling of the rear ferrule, the rear ferrule may distort slightly into the ferrule gap 77 before the flange portion 66 arrests the buckling of the rear ferrule. However, when there is no buckling, during normal make up the gap 77 is maintained. It should be noted that the width of the ferrule gap 77 in FIG. 4 is exaggerated for ease of illustration.
[0029] Additionally, it should be noted that there is within the nut member 14 a second counterbore 70 that is sized and arranged so as to closely enclose the rear end diameter of the front ferrule and constrain its radial outward movement during the tightening of the nut member 14 to the tube gripping position. In this way, both the front ferrule and the rear ferrule are radially constrained by the nut member while the nose portion of the rear ferrule is further constrained and guided by the counterbore 68 in the rear of the front ferrule 36 . By so guiding and constraining the rear ferrule at both the axial inner and outer ends, it is caused to move progressively inward while it drives the front ferrule into its gripping position. This controlled movement prevents torsional twisting and constrains the gripping movement to avoid “bear clawing” or the over deflection or rolling of the nose portion of the rear ferrule. In addition, by so moving the force receiving surface of the front ferrule inwardly of the rear face, there appears to be a better ability of the rear ferrule to constrain and control the forces applied thereto.
[0030] [0030]FIG. 3 shows the components after the nut member 14 has been moved from the finger tight position of FIG. 2 to the “made-up,” fully engaged tube gripping position. It is important to note that the length of central section 54 of rear ferrule 38 is related to the counterbore 58 of the coupling nut 14 and the cylindrical bore 68 so as to prevent any possibility of engagement between the end face 66 a of flange portion 66 and end face 70 a of second counterbore 70 (see FIG. 4). This assures that gap G is maintained at all times, even after makeup of the fitting as seen in FIG. 3. By maintaining the gap G, a spring action is retained by the ferrules. This assures a seal is maintained throughout thermal cycling and vibration. Also, it permits subsequent remake of the fitting. The gap G in the disclosed embodiment is located between the end face 66 a of the front ferrule and the end face 70 a of the coupling nut 14 . However, the gap may be located between other elements, such as between the front ferrule and the rear ferrule, depending upon the particular arrangement and shapes of the components in the tube coupling. Although the components surrounding the gap may vary, it is preferable that the gap be sized and located so as to allow for deformation of the front ferrule 36 and rear ferrule 34 . As the fitting is repeatedly made up, the front ferrule 36 and/or the rear ferrule 34 may plastically deform such that the front ferrule moves into the gap G. The rear ferrule may be compressed, or the front ferrule may acted upon such that the flange portion 66 is urged into the gap. The gap G provides an axially-extending space into which the ferrule may deform to allow repeated make ups of the fitting. There may be deformation of the ferrules after each make-up of the fitting, and the gap G accommodates the accumulated deformations. The gap preferably is large enough to accommodate significant deformation of the ferrule, and preferably extends axially a significant distance relative the central body portion 56 of the rear ferrule 38 . In one embodiment, the gap extends about one-third the length of the central body portion 56 .
[0031] The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A phase controlled sequential gripping tube fitting for gripping a tube therein, the fitting comprising a rear ferrule shaped to receive the tube therein, the rear ferrule having a nose portion and a central body. The tube fitting further comprises a front ferrule having an axially-extending rear portion radially outwardly spaced from the rear ferrule, whereby when the rear ferrule is urged axially in a first direction the rear ferrule grips the tube, and whereby the rear portion of the front ferrule reduces buckling of the rear ferrule. | 5 |
This application is a continuation of application Ser. No. 777,759, filed Sept. 19, 1985, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle having steerable front wheels and steerable rear wheels, and more specifically to a rear wheel steering angle control system arranged to limit a swing motion of a rear end of the vehicle in a direction opposite to a turn direction of the vehicle.
2. Description of the Prior Art
Japanese Patent provisional publication No. 58-97566 shows a conventional steering system for steering both front and rear wheels of a vehicle. When an angular displacement of a steering wheel is greater than a predetermined angle (that is, a small turning radius is required), this steering system steers the rear wheels in a direction opposite to a steering direction of the front wheels in order to reduce the turning radius. If, for example, the driver of a vehicle 30 shown in FIG. 4 starts the vehicle and simultaneously turns front wheels 19 and 20 to the right to move the vehicle in a direction shown by an arrow "A" away from a parking place adjacent to a wall 40, then the steering system of this conventional example turns rear wheels 21 and 22 to the left, and causes a rear end of the vehicle to swing in a leftward direction shown by an arrow "B". Therefore, the rear end bumps against the wall 40.
3. Description of the Related Art
A related U.S. patent application, Ser. No. 703,593, filed on Feb. 20, 1985 shows a steering system arranged to prevent such a collision of a rear end of a four wheel steer vehicle. However, this steering system tends to needlessly deteriorate the steering response of the rear wheels.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a rear wheel steering control system for a four wheel steerable vehicle, arranged to avoid the possibility of a collision of the vehicle rear end against an adjacent obstruction on a side of the vehicle opposite to the turning direction of the vehicle caused by steering the rear wheels in a direction opposite to the steering direction of the front wheels, and to minimize the possibility of an unnecessary retardation of the steering response of the rear wheels.
As shown in FIG. 1, according to the present invention, a rear wheel steering control system for a vehicle having steerable front wheels and steerable rear wheels comprises a front wheel angle sensing means 103 for sensing an actual front wheel steering angle of the front wheels, a rear wheel actuating means 104 for steering the rear wheels in a direction represented by a control signal in such an amount that an actual rear wheel steering angle of the rear wheels is made equal to a steering angle represented by the control signal, and a rear wheel control means 105 for producing the control signal to control the rear wheels. The control means is connected with the front angle sensing means, and determines a desired rear wheel steering angle in accordance with the actual front wheel angle currently sensed by the front angle sensing means. The control means has at least a first control mode in which the control means produces the control signal so that the rear wheels are steered in an opposite direction to a steering direction of the front wheels and the actual rear wheel angle is maintained equal to the desired rear wheel angle. The control means determines whether the vehicle is in a predetermined condition. The control means controls the rear wheels by modifying the control signal so that the actual rear wheel angle approaches the desired rear wheel angle gradually if the control signal is produced in the first control mode and at the same time the vehicle is in the predetermined condition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a control system of the present invention,
FIG. 2 is a schematic view of a vehicle equipped with the control system of one embodiment of the present invention,
FIG. 3 is a flowchart of a control program used in a first embodiment of the present invention,
FIG. 4 is a view for showing an outward swing of a rear end of a vehicle,
FIG. 5 is a diagram showing a relation between the actual rear wheel steering angle and a distance traveled by the vehicle, obtained by a delayed rear wheel control of the first embodiment,
FIG. 6 is a schematic view for showing a movement of the vehicle controlled by the control system of the first embodiment,
FIG. 7 is a flowchart of a control program used in a second embodiment of the present invention,
FIG. 8 is a timing chart showing changes of actual front wheel steering angle θ F , vehicle speed V and actual rear wheel steering angle θ R when the vehicle is moved out of a parking place,
FIG. 9 is a flowchart of a control program used in a third embodiment of the present invention,
FIG. 10 is a view for showing a modification of the program of FIG. 9, and
FIG. 11 is a flowchart of a control program used in a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention is shown in FIGS. 2 and 3.
Front wheels 19 and 20 of a vehicle are steered by a front wheel steering mechanism 12 of a conventional mechanical linkage type or a type having a power steering. An actual front wheel steering angle through which the front wheels 19 and 20 are steered is proportional to an angular displacement of a steering wheel 14.
Rear wheels 21 and 22 are steered by a hydraulic actuator 7 which has a piston 7a and a piston rod 7b. Left and right ends of the piston rod 7b are connected with knuckle arms 23 and 24 of the rear wheels 22 and 21, respectively. The piston 7a is moved axially in accordance with a fluid pressure difference between left and right pressure chambers of the actuator 7.
An operating oil is supplied to the hydraulic actuator 7 from an oil pump 3 through an unloading valve 5, an accumulator 8, a supply passage 9 and a servo valve 6. The oil is returned to an oil tank 4 through a return passage 10. The oil pump 3 is driven by an engine 1 of the vehicle through a belt 2.
A controller 11 controls an actual rear wheel steering angle through which the rear wheels 21 and 22 are steered, by controlling a displacement of the piston 7a of the hydraulic actuator 7 through the servo valve 6. A servo amplifier 18 receives a control signal indicative of a desired rear wheel steering angle, produced by the controller 11, and drives the servo valve 6 in accordance with the control signal of the controller 11.
The controller 11 receives various signals from a vehicle speed sensor 13, a steering wheel angle sensor 16, a displacement sensor 17, a gear position sensor 25 and a selector switch 26.
The vehicle speed sensor 13 is provided in a transmission of the vehicle, and produces a pulse signal P whose pulse repetition frequency (rate) is proportional to a rotational speed of an output gear of the transmission.
The steering wheel angle sensor 16 may be in the form of an encoder or a potentiometer, and produces a signal θ 1 proportional to a steering angle of the steering wheel 14. The signal θ 1 corresponds to the actual front wheel steering angle. Therefore, the steering wheel angle sensor 16 serves as a sensor for sensing an actual front wheel steering angle.
The displacement sensor 17 produces a signal θ 2 proportional to a displacement of the piston rod 7b of the hydraulic actuator 7. Therefore, the signal θ 2 corresponds to the actual rear wheel steering angle. The displacement sensor 17 may be in the form of a potentiometer or an encoder.
The gear position sensor 25 detects whether the gear position of the transmission is a forward driving position.
The selector switch 26 is operated manually by the driver of the vehicle. The selector switch 26 has an off position, an on position and an automatic control position, and produces an output signal S.
FIG. 3 shows a control program of the first embodiment performed in the controller 11.
The control program is repeated at regular intervals of a predetermined time length. At a step 201, the controller 11 calculates a desired rear wheel steering angle θ R . The controller 11 reads the steering wheel angle θ 1 sensed by the steering wheel angle sensor 16. and determines the desired rear wheel angle θ R from the steering wheel angle θ 1 which corresonds to the actual front wheel steering angle θ F so that θ R is proportional to θ F . In this embodiment θ R =θ F (The steering direction of the rear wheels is opposite to the steering direction of the front wheels.).
At a step 202, the controller 11 determines whether the selector switch 26 is in its off position or not. If it is, the controller 1 proceeds to a step 209 and outputs a control signal indicative of the desired rear wheel angle θ R determined at the step 201 to the servo amplifier 18.
In this case, therefore. the rear wheels 21 and 22 are steered simultaneously with the front wheels 19 and 20 in such a manner that the actual rear wheel angle is equal to the actual front wheel angle θ F but the steering direction of the rear wheels is opposite to the steering direction of the front wheels.
If the selector switch 26 is in the on position, the controller 11 proceeds from the step 202 to a step 203 for further determining whether the selector switch 26 is in the on position, and in response to an affirmative answer of the step 203, the controller 11 proceeds from the step 203 to steps 204 and 205.
At the step 204, the controller 11 determines a delayed rear wheel steering angle θ R *. In this embodiment, the delayed rear wheel angle is determined from the actual front wheel angle θ F , an actual rear wheel steering angle θ R obtained from the output signal θ 2 of the displacement sensor 17, and the output signal P of the vehicle speed sensor 13. A travel distance L traveled by the vehicle is determined by counting the number of pulses of the signal P of the vehicle speed sensor 13. When the travel distance L reaches a predetermined distance l, the controller 11 determines the delayed rear wheel angle θ R * by the following equation (1).
θ.sub.R *=θ.sub.R +K(θ.sub.R -θ.sub.R) (1)
(0<K≦1)
Each time the total travel distance is increased by l, the controller 11 updates the delayed angle θ R * by substituting current values of θ R and θ R into the equation (1).
At the step 205, the controller 11 substitutes the thus-determined delayed rear wheel angle θ R * for the desired rear wheel steering angle θ R determined at the step 201. At the step 209, the controller 11 outputs the signal of the desired angle θ R which, in this case, is set equal to the delayed angle θ R *.
While the steering wheel 14 is held in a turned position away from the straight ahead, or neutral, position and at the same time the selector switch 26 is held in the on position, the controller 11 repeats the steps 201, 202, 203, 204, 205 and 209. Therefore, the actual rear wheel steering angle θ R approaches the desired angle θ R (θ R =θ F ) calculated at the step 201 gradually in a stepwise manner each time the vehicle travels the predetermined distance l, as shown in FIG. 5. In FIG. 5, the travel distance traveled by the vehicle until the actual rear wheel angle reaches the desired rear wheel angle is about 1 m, for example.
In this way, the control system of this embodiment steers the rear wheels gradually with a delay with respect to the front wheels, and by so doing causes the outside rear end of the vehicle (that is, the left rear end in the case of the right turn of the vehicle) to move along an arc C of a one dot chain line in FIG. 6. Therefore, the vehicle can go away from the initial position safely without a lateral collision even if there is an obstruction on one side of the vehicle.
If the selector switch 26 is in the AUTO position, the controller 11 proceeds to steps 206-208 and performs the delayed rear wheel angle control of the steps 204 and 205 only when predetermined conditions are fulfilled.
At the step 206, the controller 11 first determines whether the control is in an opposite phase mode in which the rear wheels are to be steered in the direction opposite to the steering direction of the front wheels.
At the next step 207, the controller 11 determines whether the vehicle is in a forward motion. When the vehicle is steered while moving backwardly, the front of the vehicle swings outwardly and tends to bump against a wall or other obstruction. In this case, however, the driver can avoid a collision of the front of the vehicle by turning the steering wheel easily.
At the step 208 the controller 11 determines whether the rear wheel steering angle is increasing or not. If the rear wheel steering angle is increased in the direction opposite to the front wheel angle, then the possibility of a lateral collision of the rear of the vehicle increases. If, on the other hand, the rear wheel steering angle is being reduced, the possibility of collision becomes sufficiently small.
It is possible to sufficiently avoid the possibility of a collision of the rear end of the vehicle against an object lying alongside the vehicle by imposing only one or the other of the two conditions of the step 207 to check if the vehicle is moving forwardly and the step 208 to check if the rear wheel angle is in an increasing state.
The control system of this embodiment, however, imposes both of the conditions of the steps 207 and 208 in order to reduce the probability of the delayed rear wheel control of the steps 204 and 205. Therefore, the control system of this embodiment can reduce the possibility of an unnecessary retardation of the steering response of the rear wheels. When the selector switch 26 is in the AUTO position, the controller 11 performs the steps 204 and 205 only if all of the answers of the steps 206, 207 and 208 are affirmative.
The controller 11 determines whether the rear wheel control is in the opposite phase mode or not, by checking the actual front wheel angle θ F and the actual rear wheel angle θ R , or by checking the desired rear wheel angle θ R determined at the step 201. The controller 11 determines whether the vehicle is in the forward driving condition or not, by checking the output signal of the gear position sensor 25. The controller 11 determines whether the rear wheel angle in the increasing condition or not, by checking a change (or time derivative) of the actual rear wheel angle θ R (or the desired rear wheel angle θ R ) or by checking if the desired angle θ R determined at the step 201 is greater than the currently sensed actual rear wheel angle.
In this way, the control system of this embodiment can automatically retard the steering response of the rear wheels 21 and 22 only when the rear end outward swing is undesired such as when the vehicle must go out of a parking position alongside the wall 40 by turning right or left as shown in FIG. 4. Under other circumstances, the control system of this embodiment maintains the good steering response.
In the delayed rear wheel angle control of this embodiment, the actual rear wheel angle θ R approaches the desired rear wheel angle θ R gradually each time the distance traveled by the vehicle increases by a predetermined amount. However, the delayed rear wheel angle control of the step 204 may be arranged so that the actual rear wheel angle θ R approaches the desired rear wheel angle θ R gradually each time a predetermined time interval elapses.
In the equation (1), the correction quantity K(θ R -θ R ) added to the currently sensed actual rear wheel angle θ R is decreased as the difference θ R -θ R decreases. However, it is optional to make the correction quantity constant. In this case, the actual rear wheel angle is increased gradually by a constant amount each time the vehicle travels the predetermined distance.
The rear wheel control system of the present invention may be arranged to determine the desired rear wheel angle so as to steer the rear wheels in the opposite direction in a low speed range and in the same direction as the front wheels in a high speed range. Furthermore, the desired rear wheel angle determined at the step 201 may be equal to a product of the actual front wheel angle and a predetermined ratio which is variable with the vehicle speed.
The U.S. patent application Ser. No. 703,593 mentioned above (which corresponds to a Japanese patent application appln. No. 59-30144 and a West German patent application No. P35 06 048.4) shows three examples of the delayed rear wheel steering control in FIGS. 3, 5 and 7. The delayed rear wheel control of the present invention may be arranged to perform one of these three examples.
A second embodiment of the present invention is shown in FIG. 7. A control system of the second embodiment has a construction which is identical to the construction of the first embodiment shown in FIG. 2. However, the control system of the second embodiment does not have the selector switch 26. A control program of the second embodiment is shown in FIG. 7.
The controller 11 of the second embodiment repeates the control program of FIG. 7 at regular time intervals.
A step 301 is similar to the step 201 of the first embodiment shown in FIG. 3. In the second embodiment too, the desired rear wheel angle θ R is determined as being equal to the actual front wheel angle (that is, θ R =θ F .).
At a step 302, the controller 11 determines whether the vehicle speed V obtained from the output signal P of the vehicle speed sensor 13 continues to be equal to or lower than a predetermined value V O (for example, V O =several km/h) during a predetermined time interval (or during the time that the vehicle travels a predetermined distance).
If the answer of the step 302 is affirmative, the controller proceeds to a step 303, at which the controller 11 clears the desired rear wheel angle θ R determined at the step 301 to zero.
Then, the controller sets a flag to one at a step 304, and outputs the desired rear wheel angle θ R which is cleared at the step 303, to the servo amplifier 18 at a step 305. Therefore, in this case. the rear wheels 21 and 22 are restored to a straight ahead position.
If the answer of the step 302 is negative, the controller 11 proceeds to a step 306, at which the controller 11 determines whether the flag is equal to one or not. If the flag is one, the controller 11 performs the delayed rear wheel angle control at steps 307 and 308 similar to the steps 204 and 205 of FIG. 3.
That is, at the step 307, the controller 11 updates the value of the delayed rear wheel angle θ R * by substituting the current values of θ R and θ R into the equation (1) each time the distance traveled by the vehicle increases by a predetermined amount, or each time a predetermined time interval elapses. At the step 308, the controller 11 replaces the value of the desired rear wheel angle θ R determined at the step 301 by the value of the delayed rear wheel angle θ R * determined at the step 307. Then at the step 305, the controller 11 outputs the desired angle θ R whose value is equal to the delayed angle θ R *.
At a step 309, the controller 11 determines whether a total travel distance L T traveled by the vehicle is equal to or greater than a predetermined value L O . If L T ≧L O , the controller 11 resets both of the flag and the total distance L T to zero at a step 310.
Therefore, after the flag is set at the step 304, the controller 11 repeates the steps 301, 302, and 306-309 until the total distance L t becomes equal to or greater than the predetermined value L O . However, if the answer of the step 302 becomes affirmative during this, the rear wheels are returned to the straight ahead position again.
Therefore, as shown in FIG. 5, the actual rear wheel angle θ R gradually approaches the desired rear wheel angle θ R determined at the step 301 (in this embodiment, θ R =θ F ) in a stepwise manner each time the vehicle travels the predetermined distance l (or each time the predetermined time interval elapses) as in the first embodiment.
If both answers of the steps 302 and 306 are NO, then the desired rear wheel angle θ R determined at the step 301 is outputted directly without being changed. In this case, the rear wheels are steered immediately without delay with respect to the front wheels in such a manner that the steering angle is equal but the steering direction is opposite.
FIG. 8 shows changes of the actual rear and front wheel angles and the vehicle speed obtained by the control system of the second embodiment when the vehicle is turned to right as shown by an arrow A in FIG. 4.
In the example shown in FIG. 8. at a point t 1 of time, the driver starts the vehicle and at the same time turns the steering wheel through a large angle of turn to the right. Accordingly, the front wheels are turned through a large angle to the right while the vehicle speed is almost zero. The rear wheels are turned in accordance with the delayed rear wheel angle θ R *, and the actual rear wheel angle θ R is increased gradually in the left direction.
Then, the driver stops the vehicle at a time point t 2 to ascertain safety. Therefore, the vehicle continues at rest, and the vehicle speed continues in a rest or slow condition that V≦V O from the time point t 2 to a time point t 4 . A time point t 3 lies between the time points t 2 and t 4 , and a time length between the points t 2 and t 3 is equal to the predetermined time interval T O . Therefore, the rear wheels are turned to the straight ahead position at the time point t 3 . From the time point t 4 , the vehicle starts moving again, and the rear wheels are turned again from the straight ahead position gradually.
If the vehicle is stopped again at a time point t 5 , the same steering actions are performed at time points t 6 and t 7 .
In this way, the control system of this embodiment can prevent an undesired rear end outward swing properly and avoid the possibility of a lateral collision of the vehicle rear end against an obstruction. If, for example, the vehicle stops at an intersection and a motorcycle stops closely on the left side of the controlled vehicle, the control system of this embodiment can permit the controlled vehicle to turn to the right safely without bumping the left rear end against the motorcycle.
A counter for measuring the travel distance by counting pulses of the signal P may be arranged to start counting when the vehicle starts moving, or when the answer of the step 302 is changed to the negative answer.
A third embodiment of the present invention is shown in FIG. 9. The steps 301, 303-310 are identical to the steps 301, and 303-310 of FIG. 7, respectively.
At a step 320, the controller 11 of the third embodiment determines whether the gear position of the transmission is maintained unchanged in the forward driving position or in the reverse position in the rest or slow condition in which the vehicle speed V is equal to or lower than the predetermined value V O . If the gear position is not changed between the forward and reverse positions while V≦V O , the flag is set to one, so that the delayed rear wheel control of the step 307 is performed thereafter.
The gear position is changed between the forward and reverse positions when it is required to place the vehicle in a narrow space between other vehicles parked one behind another. In such a situation, the good steering response is preferable to the delayed rear wheel control.
The third embodiment does not employ the selector switch 26 shown in FIG. 2. However, it is optical to substitute a step 330 shown in FIG. 10 for the step 320 in FIG. 9.
It is optional to remove the step 303 to return the rear wheels to the straight ahead position from the program of FIG. 7 or the program of FIG. 9.
A fourth embodiment of the present invention is shown in FIG. 11. The control system of the fourth embodiment has a construction identical to the construction shown in FIG. 2 except that the system of the fourth embodiment does not have the selector switch 26.
In the control program of FIG. 11, the controller 11 determines whether the actual rear wheel angle θ R is equal to or greater than a predetermined angle θ O at a step 311. When the actual rear wheel angle θ R is small enough, a rear end outward swing of the vehicle is not so harmful. Therefore, the control system of the fourth embodiment performs the delayed rear wheel control of the step 307 only when θ R is equal to or greater than θ O .
In the fourth embodiment, the controller 11 further determines whether the actual rear wheel angle θ R is equal to zero, at a step 312. In most cases, vehicles are parked with front and rear wheels in the straight ahead position. If the front and rear wheels remain in turned positions occupied when the vehicle was maneuvered into the parking place, it is considered that the vehicle can go out of this parking place safety with the front and rear wheels held in these turned positions, and accordingly the delayed rear wheel control is unnecessary. In view of this, the step 312 requires the controller to determine whether the vehicle is started in the state in which the rear wheel angle θ R is equal to zero. It is optional to substitutes the actual front wheel angle θ F for the rear wheel angle θ R in the step 312. In this case, the controller determines at the step 312 whether θ F is equal to zero.
It is optional to remove the step 302 from the program of FIG. 11 and to insert the step 320 of FIG. 9 or step 330 of FIG. 10 into the program of FIG. 11 in place of the step 302.
The rear wheel steering control system of the present invention may be arranged to determine the necessity of the delayed rear wheel control by detecting obstructions with an ultrasonic sensor system which transmits ultrasonic waves and receives waves reflected back from an obstruction. In this case, the controller commands the delayed rear wheel control, such as the steps 204 and 205 and the step 303, if the ultrasonic sensor system detects an objection within a predetermined range. | A rear wheel steering control system for a four wheel steerable vehicle has a controller such as a microcomputer for steering rear wheels through a hydraulic actuator. When a small turning radius is required, the controller steers the rear wheels in an opposite direction to a direction in which the front wheels are steered. The control system further has various sensors such as front wheel angle sensor, rear wheel angle sensor, vehicle speed sensor and gear position sensor for sensing a position of a transmission. From one or more of the sensor output signals, the controller determines whether the vehicle is in a predetermined condition in which the rear wheel steering action in the opposite direction should be restrained in order to prevent the rear end of the vehicle from swinging laterally in the opposite direction and bumping against an adjacent object. If it is determined that the vehicle is in the predetermined condition, the controller steers the rear wheels gradually in the opposite direction. | 1 |
RELATED APPLICATION
This is a division of application Ser. No. 08/930,777 filed Oct. 8, 1997 now U.S. Pat. No. 6,713,605, which is a National Phase application of Application Ser. No. PCT/US96/04674 filed Apr. 10, 1996, and a continuation-in-part of application Ser. No. 08/419,066 filed Apr. 10, 1995, now U.S. Pat. No. 5,830,993, all of which are incorporated by reference herein.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with government support under Grant No. 93-37206-9351 awarded by the USDA. The government has certain rights in the invention.
SEQUENCE LISTING
A Sequence Listing containing 9 sequences in the form of a computer readable ASCII file in connection with the present invention is incorporated herein by reference and appended hereto as one (1) original compact disk in accordance with 37 CFR 1.821(c), an identical copy thereof in accordance with 37 CFR 1.821(e), and one (1) identical copy thereof in accordance with 37 CFR 1.52(e).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with methods of inhibiting leukocyte superoxide anion (O 2 − ) production and methods of attracting a leukocyte to a location using peptides. More particularly, the invention relates to methods employing a naturally occurring proline-arginine (PR)-rich antimicrobial peptide known as PR-39 and analogs thereof; these peptides can be used as medicaments that fight infection by attracting leukocytes to a wound site, yet restrict tissue damage at the wound site caused by excessive oxygen radicals produced by these leukocytes.
2. Description of the Prior Art
Infectious diseases are a primary cause of morbidity and mortality in humans and animals. These maladies range from the troublesome, e.g., Escherichia coli diarrhea which is caused by the consumption of contaminated food and drinks, to the deadly, e.g., AIDS.
A variety of antimicrobial agents have been developed to combat infectious diseases. Recently, several types of antimicrobial peptides have been discovered. Such peptide antimicrobials are produced by many biological organisms and are important components of host defense mechanisms. (Boman, 1991; Zasloff, 1992; Gabay, 1994; Boman, 1995, Martin et al., 1995) For example, defensins are expressed in several mammalian species (Lehrer et al., 1993), magainins have been identified in the skin and intestine of frogs (Zasloff, 1987; Moore et al., 1992), and cecropins have been isolated from insects and pigs (Steiner et al., 1981; Lee et al., 1989). These natural antimicrobials are lytic peptides that kill microorganisms by pore-forming, membrane-damaging mechanisms (Boman et al., 1993; Maloy et al., 1995).
The patent art also discloses antimicrobial peptides. U.S. Pat. No. 5,234,716 describes broad spectrum tryptophan antimicrobial peptides, and U.S. Pat. No. 5,202,420 discloses tracheal antimicrobial peptides.
Recently, a group of PR-rich antibacterial peptides have been identified. Bactenecins 5 and 7 have been isolated from bovine neutrophils (Gennaro et al., 1989; Litteri et al., 1993), and PR-39 was first isolated from the porcine small intestine (Agerberth et al., 1991) and identified recently in porcine and human neutrophils (Shi et al., 1994b; Shi et al., 1995). Although these PR-rich antibacterial peptides share a similar high content of proline (47, 47, and 49%, respectively) and arginine (21, 29, and 26%, respectively), they possess different killing mechanisms.
Similar to other lytic peptides, bactenecins kill bacteria by a membrane-permeability-associated mechanism (Maloy et al., 1995); however, PR-39 was found to kill bacteria by interfering with DNA and/or protein synthesis (Boman et al., 1993). Furthermore, PR-39 has been isolated from wound fluid and was shown to induce syndecan expression on mesenchymal cells (Gallo, 1994). Because syndecans are important in wound repair, this finding suggests that PR-39, in addition to its antibacterial properties, may have a larger role in inflammatory processes and tissue repair.
Neutrophils represent a first line of defense against infections; they are the first white blood cells to arrive at sites of infection and are well-equipped to sequester and eliminate pathogens. These cells possess multiple antimicrobial defense mechanisms, including both oxidative and nonoxidative microbial killing processes (Klebanoff, 1992; Selsted et al., 1995). Nonoxidative neutrophil defense mechanisms include several antibacterial peptides including PR-39. Phagocyte oxidative defense mechanisms are initiated by a plasma membrane-bound enzyme complex called reduced nicotinamide dinucleotide phosphate (NADPH) oxidase (Rotrosen, 1992). This multicomponent enzyme catalyzes the reduction of molecular oxygen to O 2 − using NADPH as an electron donor. Although O 2 − and other reactive oxygen intermediates are important components of host defense, these highly toxic oxidants also cause significant tissue injury in inflammatory diseases and ischemia-reperfasion injury (Shasby et al., 1982; Malech, 1987; Demling, 1990; Martinez-Cayuela, 1995; Granger et al., 1995). Thus, their generation and inactivation must be tightly regulated.
At least five proteins comprise the NADPH oxidase complex; a membrane flavocytochrome b 558 , which is composed of two subunits (gp91 phox and p22 phox ); and three cytosolic components (p47 phox , p67 phox , and a GTP-binding protein named p21 Rac ) (Rotrosen et al., 1992; Abo et al., 1992). Although mechanisms for activation and assembly of NADPH oxidase have not been elucidated fully, it is clear that multiple protein-protein interactions among its components are regulated by a number of signaling intermediates (McPhail et al., 1993). The assembly of phagocyte NADPH oxidase requires protein-protein interactions between Src homology 3 (SH3) domains in cytosolic components and proline-rich regions in other components (Leto et al., 1994; Sumimoto et al., 1994; Finan et al., McPhail, 1994; de Mendez, 1996).
SUMMARY OF THE INVENTION
The present invention is predicated upon the discovery that specific peptides (e.g., PR-39) are capable of 1) inhibiting O 2 − synthesis by leukocyte enzymes (e.g., NADPH oxidase), and 2) attracting leukocytes (e.g., neutrophils). These peptides can be used as novel medicaments that fight infection by attracting leukocytes to a wound site, yet restrict tissue damage at the wound site caused by excessive oxygen radicals produced by these leukocytes. Preferably, these peptides have a sequence included in PR-39 (e.g., Sequence ID Nos. 1 and 2 for peptides capable of inhibiting O 2 − production, and Sequences ID Nos. 1, 2, 5, 6, and 7 for peptides capable of attracting leukocytes). Advantageously, these peptides are synthesized and have lengths of less than 60 amino acid residues, and the leucocytes upon which the peptides act are mammalian (e.g., porcine) leucocytes. This invention was made with government support under Grant 93-37206-9351 awarded by the United States Department of Agriculture. The government has certain rights in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the amino acid sequence of PR-39 and various truncated analogs thereof, wherein the single letter amino acid code is used and the left side of the sequence is the NH 2 -terminal end;
FIG. 2 is a protein hydrophilicity (solid line) and antigenicity (dashed line) plot for PR-39 wherein the hydrophilic and antigenic domains are above the horizontal line and the hydrophobic domains are below the horizontal line;
FIG. 3 is a photograph of an AU-PAGE analysis of synthetic peptides wherein each lane contains ten micrograms of peptide; lane 1=PR-14; lane 2=PR-15; lane 3=PR-16; lane 4=PR-26; lane 5=PR-39; and lane 6=neutrophil granule extract, with calculated molecular weights (MW cal ) over the experimental mass spectrometry data (MW exp ) listed above each lane for the respective synthetic peptides;
FIG. 4 is a photograph of the gel shown in FIG. 3 after being subjected to a gel-overlay assay, wherein the clear zones indicate antibacterial activity;
FIG. 5 is a photograph of an agar plate showing the results of an antibacterial “lawn-spotting” assay using Salmonella typhimurium wherein the spot positions are numbered on the left of the photograph; position 1=medium control (0.01% acetic acid); positions 2, 3, and 4=PR-14, PR-15, and PR-16, respectively, at 1 mg/ml in 0.01% acetic acid; positions 5 and 6=100 μmoles and 50 μmoles, respectively, of PR-26 in phosphate buffer saline, pH 7.4; positions 7, 8, 9, and 10=100, 50, 25, and 10 μmoles, respectively, of PR-26 in 0.01% acetic acid; and positions 11, 12, and 13=100 μmoles, 50 μmoles, and 25 μmoles, respectively, of PR-39 in 0.01% acetic acid;
FIG. 6 is a photograph of a 96-well microtiter plate used to determine the minimal inhibitory concentrations of PR-26 and PR-39 against enteric bacteria;
FIG. 7 is a graph illustrating the postantibiotic effect of PR-26 and PR-39 against S. typhimurium;
FIG. 8 is a graph illustrating the phagocytic susceptibility of S. choleraesuis after exposure to PR-26 and PR-39;
FIG. 9 is a graph illustrating the chemotaxis of porcine neutrophils by PR-39 and analogs thereof;
FIG. 10 is a graph illustrating a dose response of PR-39 for neutrophil chemotaxis;
FIG. 11 is a graph illustrating the cytotoxicity of PR-26 and PR-39 in intestinal epithelial cells;
FIG. 12 is a graph illustrating percent survival of A/J mice 15 days after an oral challenge with S. typhimurium followed with 0, 100, or 250 μg PR-26;
FIG. 13 is a graph illustrating survival of mice infected with S. typhimurium intraperitonealy (i.p.) followed with 0, 50, or 100 μg PR-26;
FIG. 14 is a graph illustrating survival of mice infected with S. typhimurium i.p. followed with 50 μg PR-26 at time 0, 24, 48, or 72 hours post-infection;
FIG. 15 is a graph illustrating that inhibition of whole-cell NADPH oxidase activity requires preincubation with PR-39;
FIG. 16 is a graph illustrating whole-cell NADPH oxidase inhibition by PR-39 and analogs thereof;
FIG. 17 is a graph illustrating cell-free NADPH oxidase inhibition by PR-39 and analogs thereof;
FIG. 18 is a photograph of blots illustrating the binding of biotinylated PR39 to a 47 kDa neutrophil cytosol protein;
FIG. 19 is a photograph of a blot and a corresponding graph illustrating the binding of PR-39 to recombinant p47 phox ;
FIG. 20 is a photograph of blots illustrating the degrees to which PR-26 and PR-39 block the interaction between GST-p47 phox and recombinant p22 phox ;
FIG. 21 is a photograph of a blot illustrating the degrees to which PR-19 and PR-23 block the interaction between GST-p47 phox and recombinant p22 phox ; and
FIG. 22 is a photograph of a blot illustrating the degrees to which PR-14, PR-15, PR-16, and PR-26 block the interaction between GST-p47 phox and recombinant p22 phox .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following example illustrates the preferred practice of the invention. It is to be understood, however, that this example is provided by way of illustration only and nothing therein should be taken as a limitation upon the overall scope of the invention.
EXAMPLE
Materials and Methods
Peptide design and synthesis. Theoretical predictions of peptide characteristics, relative to hydrophilicity, hydrophobicity, and antigenicity, were accomplished using a computer software program (Peptide Companion, Peptide International, Louisville, Ky.). The following peptides were synthesized: PR-39, PR-26, PR-23, PR-19, PR-16, PR-15, and PR-14; the sequences of these peptides appear in the Sequence Listing as Sequence ID Nos. 1 through 7, respectively. Peptides were synthesized by the solid-phase method using t-Boc chemistry with an Applied Biosystems Model 431 Peptide Synthesizer (ABI, Foster City, Calif.). Amino acid derivatives having the L-configuration were used. Peptide purification and characterization were conducted as described previously (Shi et al., 1994b; Shi et al., 1996). Briefly, the peptides were purified on a reversed-phase high-performance liquid chromatography (RP-HPLC) system (Beckman Instruments, Fullerton, Calif.) with a Vydac 218 TP C 18 column (0.46×25 cm), analyzed by fast-atom mass spectrometry (AUTOSPEC-Q; VG Analytical Ltd., Manchester, United Kingdom), and visualized by acid-urea polyacrylamide gel electrophoresis (AU-PAGE). In the AU-PAGE analysis, peptides (10 μg) were dissolved in 20 μl of sample buffer (3M urea with 5% acetic acid) and the gels were run at 150V for approximately 15 min. or until the dye front (methyl green) had migrated to the end of the gel. The gel was stained with 0.3% amido black.
Antibacterial activity assays. Synthetic peptides were evaluated for antibacterial activity by previously described gel-overlay and “lawn-spotting” assays (Shi et al., 1994b), by determination of the minimal inhibitory concentrations (MICs) and the minimal bactericidal concentrations (MBCs) of PR-26 and PR-39, and by determination of the postantibiotic effect (PAE) of PR-26 and PR-39 and the bacterial susceptibility to neutrophil phagocytosis by PR-26 and PR-39.
(i) Gel-overlay assay. Peptides were subjected to AU-PAGE as described previously (Shi et al., 1994b). The acid-urea gels were overlaid with 10 6 bacteria ( E. coli , ATCC 25922) in 3% trypticase soy broth (TSB) and 1% agarose medium, and the overlaid gels then were incubated at 37° C. for 18 hr. Bactericidal activity was indicated by clear zones on the agarose gels. (ii) Lawn-spotting assay. Lawns of bacteria ( E. coli , ATTC 25922, or S. typhimurium , KSU isolate 7) were made on sheep-blood or brain-heart-infusion agar plates. After drying at room temperature for 10 min, 5 μl of the various peptides (dissolved in 0.01% acetic acid or phosphate buffered saline (PBS), pH 7.4) and a medium control were spotted on the surface of the bacterial lawn. Plates were incubated at 37° C. for 18 hr. Bactericidal activity was indicated by a clear zone on the bacterial lawn (Shi et al., 1994b). (iii) MICs and MBCs. For peptides that showed antibacterial activity using the gel-overlay and lawn spotting assays, MICs and MBCs were determined by the microdilution broth method (NCCLS, 1990). Briefly, 50 μl of twofold serial dilutions (128 to 0.25 μM) of synthetic peptides were dispensed into wells of 96-well tissue culture plates. Bacteria ( E. coli , ATCC 25922; E. coli , K88; S. typhimurium , fresh isolate from a dog; Salmonella choleraesuis ATCC 6962; Streptococcus suis , fresh isolate from porcine spleen; and Staphylococcus aureus ) from sheep-blood or brain-heart-infusion agar plates were standardized to 0.5 McFarland in demineralized water using a radiometer/sensititre (Chelsea Instrument Ltd., England). The water/bacteria suspension (100 μl) was immediately transferred to 10 ml of cation-adjusted Muller-Hinton broth and 50 μl of the bacterial suspension then were added to each well of the microtiter plate. Plates were incubated for 20 hr. at 37° C. and MICs were determined. Ten microliters of bacterial suspensions in Muller-Hinton broth also were diluted to determine the actual bacterial concentration using standard colony forming unit (CFU) counting. After determination of the MICs, 10 μl of each bacteria-peptide suspension were plated on sheep-blood or brain-heart-infusion agar plates and incubated for 24 hr. at 37° C. to determine the MBCs. MBC was considered that peptide concentration that inhibited 99.9% of the original CFUs (NCCLS, 1990). (iv) PAE. S. typhimurium was used to evaluate the PAE of PR-26 and PR-39. Stationary phase bacteria were adjusted to 5×10 7 bacteria/ml in brain-heart-infusion agar and incubated with different concentrations of PR-26 or PR-39 at 37° C. for 2 hr. Control tubes without PR-peptides were treated in an identical manner to the experimental tubes. PR-26 and PR-39 were removed by centrifugation (13,600×g for 1 min.) and 100 μl of the bacteria were resuspended in 0.9 ml of PR-peptide-free brain-heart-infusion agar and incubated at 37° C. Bacteria (20 μl) were diluted in sterile saline immediately after removal of the PR-peptides and then at hourly intervals, and 20 μl aliquots were spread on nutrient agar plates. Viable bacteria were counted. Tests were repeated on three different days. PAE was determined by calculating the difference in time required for the number of test and control bacteria to increase 1 log 10 above the number present immediately after removal of PR-peptides from the test cultures. The results were expressed as the mean ± standard deviation. A PAE greater than 30 min. was considered significant (MacKenzie and Gould, 1993). (v) Susceptibility to neutrophil phagocytosis. Porcine neutrophils were isolated from 6 to 8 week-old-crossbred pigs by density-gradient centrifugation and hypotonic lysis as previously described (Shi et al., 1994a). S. choleraesuis , ATCC 6962 was used in this experiment. Bacteria were incubated with PR-26 or PR-39 for 10 min. at 37° C. Peptides were removed from the bacterial cultures by centrifugation at 13,600×g for 1 min. Bacteria were resuspended in 1 ml of PBS and 0.1 ml of bacteria was mixed with 2×10 6 porcine neutrophils. The final volume was adjusted to 0.5 ml, 15% porcine serum. Bacteria without neutrophils and neutrophils without bacteria were used as controls. Tubes were incubated at 37° C. in a reciprocating water bath at 110 oscillations/min. Aliquots of 50 μl from the experimental tubes were used to prepare slides using a Cytospin 2 centrifuge (Shandon Products Ltd., Pittsburgh, Pa.). Slides were stained with LeukoStat solutions (Fisher, Pittsburgh, Pa.). Phagocytosis was determined by light microscopy at a magnification of 1,000. At least 200 neutrophils were examined. The degree of phagocytosis was calculated according to the following formula: phagocytic index=(percentage of neutrophils containing at least one bacteria)×(mean number of bacteria per positive cell). Tests were repeated on three different days. Results were expressed as the mean±standard deviation.
Influence of PR-39 on neutrophil chemotaxis. Chemotaxis of porcine neutrophils was measured by the procedure of Salak et al. (1993). Briefly, PR-14, PR15, PR-16, PR-26, or PR-39 (30 μl in Dulbecco's Modified Eagle's medium) were placed in the bottom chamber of a modified Boyden chamber (Neuro Probe, Cabin John, Md.) and porcine neutrophils (50 μl at 5×10 6 cells/ml) were placed in the top chamber. The chambers were incubated at 37° C. for 30 min. Cells that migrated through the porous membrane (pore size 5 μm) were stained using LeukoStat solution and enumerated. Five microscope fields were counted and the cells that migrated through the membrane were standardized to the medium control and referred to as the migration index.
Influence of PR-26 and PR-39 on intestinal epithelial cells. A nonradioactive assay based on the cellular conversion by viable cells of a tetrazolium salt into a blue formazan product was used to determine if PR-26 or PR-39 were toxic to intestinal epithelial cells. Ninety-six-well microtiter plates were seeded with the rat intestinal epithelial cell line, IEC-6, (5×10 4 cells/well) in DMEM containing 10% fetal bovine serum, 1% antibiotic/antimycotic, and 0.1 bovine insulin, and incubated at 37° C. for three days to achieve confluency. Cells then were incubated with different concentrations of PR-26 or PR-39 in medium without antibiotic/antimycotic for three days. Well contents then were aspirated and monolayers were washed with medium. Medium (100 μl) and 15 μl of dye solution (Promega, Madison, Wis.) were added to each well and plates were incubated for 4 hr. at 37° C. Solubilization buffer (100 μl, Promega, Madison, Wis.) was added to each well and plates were incubated overnight to allow solubilization of the formazan crystals. Absorbance then was read at 570 nm using a microplate reader.
Effect of PR-26 on survival of mice challenged with S. typhimurium . Three separate S. typhimurium challenge studies were conducted with mice. In the first experiment, 45 A/J mice (Jackson Labs, Bar Harbor, Me.) were orally challenged with S. typhimurium . Feed was withdrawn 4 hrs. prior to an oral inoculation. Twenty min. prior to the inoculation with S. typhimurium mice were given a 30 μl dose of a 10% sodium bicarbonate solution in PBS. S. typhimurium , strain KSU007, was started in brain heart infusion broth overnight and then grown for 6 hrs. in Luria Broth Base (GIBCO, Gaithersburg, Md.). After centrifugation, bacteria were suspended in a 1% gelatin solution (final concentration 1.24×10 10 S. typhimurium /ml), and then 25 μl were given orally. Immediately following oral inoculation with S. typhimurium , mice were given 0, 100, or 250 μg of PR-26 in PBS. A second dose of PR-26 or PBS was given 4 hrs. later.
In the second experiment, 45 Balb/C ( Salmonella susceptible) mice were given i.p. injections of S. typhimurium (2×10 4 /ml) that had been grown as previously described, but resuspended in PBS. Mice then received either 0, 50, or 100 μg of PR-26 in 100 μl PBS i.p. immediately after the S. typhimurium.
In the third experiment, the efficacy of timing of delivery of PR-26 was evaluated. The protocol was the same as in the second experiment, except that only the 50 μg/mouse dose of PR-26 was used and the PR-26 was delivered immediately (time 0), or 24, 48, or 72 hrs. after the S. typhimurium injection. A control group received PBS at time 0. Fifteen mice were used in all treatments except the 72-hour treatment, which had 16.
Regulation of neutrophil O 2 − production by PR-26 and PR-39.
(i) O 2 − production assays. Whole-cell O 2 − production by por-cine peripheral blood neutrophils was determined by the superoxide dismutase-inhibitable reduction of ferricytochrome c as previously described (Shi et al., 1994a). Cell-free O 2 − production was measured as previously described (Leto et al., 1991) using 96-well plates and a Molecular Devices Thermomax microplate reader (Menlo Park, Calif.). Reactions (100 μl) contained 10 6 cell equivalents of human neutrophil cytosol and 5×10 5 cell equivalents of deoxycholate-solubilized membranes prepared from human peripheral blood neutrophils. Reaction mixtures contained 50 mM potassium phosphate (pH 7), 0.2 mM acetylated cytochrome c, 4 mM MgCl 2 , 1 mM EGTA, 10 μM FAD, 1 μM GTP-γS, and 200 μM NADPH. The reactions were initiated by addition of 40 μM arachidonic acid. Control reactions contained 5 μg of superoxide dismutase. Superoxide anion generation was calculated based on superoxide dismutase-inhibitable changes in cytochrome c absorbance observed at 551 nm. The reactions were followed for 20 min. after addition of arachidonic acid, with absorbance readings taken at 1-min. intervals. Maximum rates of superoxide generation were calculated from a linear least squares fit of 10 consecutive 1-min. data points. Determinations were based on reactions performed in duplicate. (ii) Binding assays. Neutrophils were disrupted by sonication, and unbroken cells, debris, and granules were removed by centrifuigation (13,000×g for 60 min.). Cytosol fractions were prepared by centrifugation (100,000 g for 45 min.) of the supernatants to remove residual membranes. Cytosolic proteins (15 μg in reducing buffer) were separated on a 7.5% SDS PAGE gel, transferred to PVDF membranes, and probed with biotinylated PR-39 (0.3 μM) for 2 hr. Binding between PR-39 and cytosolic proteins were visualized by a chemiluminescent streptavidin alkaline phosphatase system using an Epson scanner (Torrance, Calif.) and the NIH Image program. PR-39 was labeled with biotin hydrazide at the carboxy-terminus (Pierce Chemical Co., Rockford, Ill.) and purified by gel filtration chromatography.
Competitive ligand-blot assays were performed by incubating recombinant p47 phox (0.02 μM) with or without various concentrations (0.006, 0.06, and 0.6 μM) of PR-39 for 1 hr. at 37° C. and then with biotinylated PR-39 (0.06 μM) for an additional 1 hr. at 37° C. The solutions were dialyzed against ddH 2 O for 1 hr. at 4° C. before blotting to nitrocellulose (5 μl) and detection with a streptavidin alkaline-phosphatase detection system as described above.
Methods for production of the glutathione S-transferase (GST)-p47 phox -SH3 (residues 151–284) fusion protein have been previously described (Leto et al., 1994). For solution binding assays, lysates of recombinant p22 phox protein (residues 127–195) from baculovirus-infected cells (2.5×10 4 cell equivalents per assay) were mixed with peptides and incubated for 1 hr. at 20° C. with 100 μl of GST-p47 phox bound to glutathione-Sepharose beads (15% suspension). Bound proteins were washed three times in 15 volumes of ice-cold 100 mM KCl/3 mM NaCl/3.5 mM MgCl 2 /0.15 mM phenylmethanesulfonyl fluoride/10 mM Pipes (pH 7.5), eluted with 1% SDS, and analyzed by SDS-PAGE followed by immunoblotting with mouse anti-p22 phox antibody (mAb 449; A. Verhoeven, Central Laboratories of the Netherlands Red Cross). Controls included blotting of recombinant p22 phox lysate (5×10 3 cell equivalents) alone (p22) and bound complexes detected without competing PR peptides (−).
Results and Discussion
Peptide design and synthesis. PR-39 and six analogs were synthesized and named PR-39 (whole molecule), PR-26 (NH 2 -terminal segment 1 to 26), PR-23 (control segment 4 to 26), PR-19 (NH 2 -terminal segment 1 to 19), PR-16 (central segment 11 to 26), PR-15 (COOH-terminal segment 25 to 39), and PR-14 (NH 2 -terminal segment 1 to 14). Peptide sequences are illustrated in FIG. 1 . Rationale for design of the peptides was based on the graphic protein hydrophilicity scale ( FIG. 2 ), since the hydrophilicity profile indicates locations of important interaction sites such as antibody and receptor binding sites (Hopp, 1985). PR-26 was designed to mimic the hydrophilicity profile of PR-39 which has a hydrophilic NH 2 -terminus and a hydrophobic COOH-terminus. As most endogenous antibacterial peptides are cationic molecules, PR-14, the highest positively charged segment (43% vs. 25% of whole molecule), was designed to test if cationicity itself was enough for antibacterial activity. The central domain, PR-16, having the average positive charge intensity (25%) was synthesized as the control for PR-14. PR-15, the COOH-terminus of PR-39 was designed to determine if it was one of the functional domains of PR-39. PR-23 was designed to evaluated the importance of the first three arginine residues of PR-26. PR-19 was designed to assess the contribution of the COOH-terminus to the activity of PR-26.
Calculated molecular weights and experimental determinations of the mass of synthetic peptides suggested that these peptides possessed the designed sequences (1813, 1777, 1939, 3230, and 4720 calculated molecular weight vs 1812, 1777, 1941, 3230, and 4720 experimental determination of mass for PR-14, PR-15, PR-16, PR-26, and PR-39, respectively). Synthetic peptides (>95% purity in RP-HPLC) were subjected to AU-PAGE to further determine the purity and charge intensity. FIG. 3 shows the results of this analysis for PR-14, PR-15, PR-16, PR-26, and PR-39 (data not shown for PR-19 and PR-23). As expected, PR-14 migrated in the front since it has the highest positive charge intensity; PR-15, having the lowest positive charge intensity, migrated far behind PR-14 even though its mass is slightly less than PR-14. Because PR-16 and PR-26 are smaller molecules than PR-39, they migrated faster than the parent molecule. Native PR-39 and synthetic PR-39 behaved identically in AU-PAGE and RP-HPLC analyses (data not shown).
Antibacterial Activity Assays.
(i) Gel-overlay assay. In the gel-overlay bactericidal assay, only PR-26 and PR-39 were found to have antibacterial activity against E. coli . FIG. 4 shows the results of this assay for PR-14, PR-15, PR-16, PR-26, and PR-39 (data not shown for PR-19 and PR-23). (ii) Lawn-spotting assay. In the “lawn-spotting” antibacterial assay, PR-14, PR-15, PR-16, PR-19, PR-23, PR-26, and PR-39, and the combination of PR-14, PR-15, and PR-16, were tested. FIG. 5 shows the results of this assay for PR-14, PR-15, PR-16, PR-26, and PR-39 (data not shown for PR-19, PR-23, and the combination of PR-14, PR-15, and PR-16). Only PR-26 and PR-39 had antibacterial activity. All of the other segments and their mixtures showed no antibacterial activity even at 1 mg/ml.
These results suggest that: 1) the very cationic NH 2 -terminus of PR-39 is not sufficient for antibacterial activity; 2) the COOH-terminal segment 27 to 39 does not contribute to the antibacterial activity of PR-39; 3) PR-26, the NH 2 -terminal segment 1 to 26, contains the antibacterial domain of PR-39; 4) the NH 2 -terminal segment 1 to 3 is essential for antibacterial activity; (5) the COOH-terminal segment 20 to 26 is essential for antibacterial activity; and 6) certain secondary structure conformation is required for the antibacterial activity of PR-26 and PR-39 since segment mixtures did not have any antibacterial activity. The “lawn-spotting” assay also showed that PR-26 had greater antibacterial activity against E. coli and S. typhimurium than PR-39 ( FIG. 5 ).
(iii) MICs and MBCs. The MICs of PR-26 and PR-39 for E. coli, 25922; E. coli, K 88; S. typhimurium; S. choleraesuis; S. suis ; and S. aureus are shown in FIG. 6 and Table 1. For the enteric, Gram-negative bacteria, the MICs of PR-26 and PR-39 ranged from 1 to 4 μM; PR-26 had a lower MIC than PR-39. Similarly, the MBCs of PR-26 were the same or lower than the MBCs of PR-39 and ranged from 2 to 8 μM for the Gram-negative bacteria (Table 1). These findings suggest that PR-26 maybe an effective antibiotic against enteric, Gram-negative bacteria such as E. coli or Salmonella .
TABLE 1
MICs (μM) and MBCs (μM) of PR-39 and PR-26 against six strains of
bacteria.
MIC
MBC
Bacteria
PR-39
PR-26
PR-39
PR-26
Escherichia coli, 25922
4
2
8
8
Escherichia coli, K88
2
1
4
4
Salmonella typhimurium
4
2
4
2
Salmonella choleraesuis
2
1
4
2
Streptococcus suis
>64
16
>64
>64
Staphylococcus aureus
>250
>250
ND*
ND*
*Not determined
(iv) PAE. The relationship between peptide concentration and the duration of PAE of PR-26 and PR-39 is shown in FIG. 7 . Suboptimal peptide concentrations (0.1 MIC) only caused a slight growth delay in both PR-26- and PR-39-treated bacteria. However, at 1 and 8 MICs, PAEs against S. typhimurium were significantly increased. These findings agree with other antibacterial data and show clearly that PR-26 limits the growth of enteric bacteria.
(v) Susceptibility to neutrophil phagocytosis. Bacteria treated with PR-26 were more susceptible to neutrophil phagocytosis ( FIG. 8 ; PR-26 was different from control, P<0.05). A 10 min. exposure of S. choleraesuis to 2 MICs of PR-26 significantly increased the capability of porcine neutrophils to phagocytose the bacteria. Treatment of S. choleraesuis with PR-39 at 8 MICs did not increase the phagocytic index of porcine neutrophils. Neutrophils phagocytosed both single and filamentous bacteria. These data show that, in addition to the direct antibacterial activity of PR-26, this antibacterial peptide predisposes enteric bacteria to elimination by phagocytic cells. This property suggests that PR-26 works synergistically with the host's immune system to limit enteric bacterial growth.
Influence of PR-39 on neutrophil chemotaxis. Phagocytic cells migrate from the blood to areas of inflammation in response to chemotactic agents. FIG. 9 shows that PR-14, PR-15, PR-16, PR-26, and PR-39 are chemotactic agents for neutrophils (PR-14, PR-15, PR-16, and PR-26 are used at 1 μM, and PR-39 was used at 0.05 μM; the chemoattractant C5a, a positive control, was used at 1×10 −8 M; starred entries are different from the control, P<0.05). FIG. 10 shows a dose response of PR-39 for neutrophil chemotaxis. The ability of PR-39 to function as a chemotactic agent increases the probability that sufficient phagocytic cells are present at an inflammatory site to limit an infection.
Influence of PR-26 and PR-39 on intestinal epithelial cells. FIG. 11 shows the cytotoxic activity of PR-26 and PR-39 on rat small-intestine epithelial cells (IEC-6). PR-26 was not cytotoxic to IEC-6 cells even at concentrations (20 μM) much greater than the MIC for this peptide. However, IEC-6 cells were sensitive to PR-39 as cytotoxicity occurred at 0.5 μM, which is lower than the MIC for this peptide. These data show that PR-26 does not damage cells of the small intestine and should, therefore, be a safe oral antibiotic.
Effect of PR-26 on survival of mice challenged with S. typhimurium . In the first experiment, mice that received PR-26 were resistant to Salmonella (0 and 1 death for 250 and 100 μg/mouse, respectively), but the control group had a 27% mortality rate ( FIG. 12 ; both PR-26 treatments were significantly different from controls, P<0.05). Based on these data, PR-26 was effective in increasing the survival rates in this Salmonella -resistant strain of mice. There was no evidence of toxicity caused by PR-26. In the second experiment, both 50 and 100 μg PR-26 were sufficient to increase survival to more than 50% at 14 days post-infection ( FIG. 13 ; both PR-26 treatments were different from the PBS control at days 6 through 14, P<0.05, but not different from each other. In the third experiment, administration of PR-26 was most effective when given at time 0; however, the 24-hour post-infection treatment slightly improved the survival compared to the PBS treatment by day 14 ( FIG. 14 ; treatments at 0, 24, and 72 hrs. were different from PBS control at day 15, P<0.05 for treatments at 0 and 24 hrs., P<0.10 for treatment at 72 hrs.). The delivery of PR-26 at 48 hrs. post-infection was not different than the PBS control treatment. The rapidity of uptake of S. typhimurium and delivery to the liver and spleen during an i.p. infection maybe the cause of the reduced effectiveness of PR-26 by 48 hrs. post-infection.
Regulation of Neutrophil O 2 − Production by PR-26 and PR-39.
(i) O 2 − production assays. When PR-39 was incubated with neutrophils for at least 45 min. before simulation with phorbol myristate acetate (PMA), a significant reduction in O 2 − generation was observed ( FIG. 15 ; neutrophils (1×10 6 ) were incubated without (Control) or with PR-39 (5 μM) for the indicated times before stimulation with PMA; values are means ±SEM, n=2; starred entries are different from control, P<0.05). This effect was even more apparent with longer pre-incubation periods, approaching as much as 70% oxidase inhibition. PR-26 also significantly reduced O 2 − generation ( FIG. 16 ; neutrophils were incubated with PR-39 or derivatives for 150 min. before stimulation with PMA; results are reported as % relative to control (no peptides); however, the statistical analysis was based on nmoles of O 2 − produced; values are means, n=3; starred entries are different from control, P<0.05; this experiment was conducted twice with similar results). However, the shorter peptides, PR-14, PR-15, PR-16, PR-19, and PR-23, did not significantly reduce O 2 − generation by intact neutrophils. PR-39 (20 μM) added to neutrophils at the same time as PMA activities did not affect generation of O 2 − , while longer incubation periods with this peptide did not affect neutrophil viability, as judged by trypan blue dye exclusion.
To investigate the inhibition of neutrophil O 2 − generation by PR-39 and its fragments in more detail, a cell-free assay system of O 2 − generation was used. PR-26 and PR-39 were very potent inhibitors of O 2 − generation in the cell-free assay; concentrations that inhibited 50% (IC 50 ) of O 2 − generation were approximately 1 and 2 μM, respectively ( FIG. 17 ; data are the average of duplicate reactions and are representative of 3 to 4 independent experiments; control (100%) activities ranged from 0.9 to 2.4 nmol O 2 − /min/5×10 5 cell equi-valents of membrane). At concentrations greater than 5 μM, both proline-rich peptides completely inhibited the generation of O 2 − . PR-15 and PR-16 did not affect O 2 − generation; however, PR-14 did reduce O 2 − generation at concentrations greater than 25 μM.
PR-19 and PR-23 had some oxidase inhibitory activity; IC 50 's of PR-19 and PR-23 were approximately 5 μM and 25 μM, respectively ( FIG. 17 ). These findings suggest that both peptides contain the oxidase inhibitory domain, although the first three arginine residues of PR-26 contribute greatly to oxidase inhibitory activity.
(ii) Binding assays. The findings that PR-26 and PR-39 inhibited both cell-free and whole cell O 2 − production by neutrophils and that inhibition required preincubation of cells with peptides for at least 45 min. prior to PMA stimulation suggested that these peptides act through some intracellular target, such as the NADPH oxidase components themselves. To determine if PR-39 bound to specific neutrophil cytosol components, human and porcine cytosolic proteins were separated by SDS-PAGE, transferred to a PVDF membrane, and probed with biotinylated PR-39. Using this ligand-blot binding assay, it was found that PR-39 bound to a 47 kDa protein in both human and porcine cytosol preparations ( FIG. 18 ; cytosolic protein (50 μg) from human and porcine polymorphonuclear (hPMN and pPMN) leukocytes was subjected to SDS-PAGE, transferred to a PVDF membrane, and then probed with biotinylated PR-39; molecular masses of standards in kDa are shown on the left of the blots).
Competitive binding assays were conducted to determine if PR-39 bound to recombinant p47 phox . These solution binding experiments with pure recombinant p47 phox and PR-39 showed that increasing concentrations of nonbiotinylated PR-39 inhibited specific binding of biotinylated PR-39 to recombinant p47 phox ( FIG. 19 ; competitive binding analysis was conducted by incubating various concentrations of PR-39 with recombinant p47 phox and then with biotinylated PR-39; after dialysis, solutions were dot-blotted onto PVDF membranes and probed for bound biotinylated PR-39). Binding was inhibited 90% at equimolar concentrations of labeled and unlabeled peptide (0.06 μM) and was completely blocked by a tenfold excess of unlabeled peptide. This finding shows that PR-39 binds to p47 phox , that binding is specific, and implies that PR-39 decreases O 2 − generation by interferring with this cytosolic component of the NADPH oxidase complex.
At least two proline-rich sequences, the COOH-terminal region (residues 358–371) of p47 phox and the cytoplasmic region (residues 149–162) of p22 phox , are thought to bind to SH3 domains of p67 phox and p47 phox , respectively, and are essential for the activation of NADPH oxidase in vivo (Leto et al., 1994; Sumimoto et al., 1994; Finan et al., 1994; McPhail, 1994; de Mendex et al., 1996). Data obtained by probing neutrophil cytosolic proteins with biotinylated PR-39 suggested that PR-39 did not bind to p67 phox ( FIG. 18 ). Because PR-39 bound directly to p47 phox , it was reasoned that PR-39 could interfere with assembly of NADPH oxidase by blocking its interaction with p22 phox .
To examine this hypothesis, solution binding assays were conducted between GST-p47 phox SH3 domain fusion protein and a recombinant p22 phox cytoplasmic domain (residues 127–195) in the presence or absence of PR-39 or its derived fragments. PR-26 and PR-39 effectively blocked the inter-action between GST-p47 phox and recombinant p22 phox at concentrations close to their IC 50 's observed in the cell-free oxidase assay ( FIG. 20 ; PR-26 or PR-39 were mixed with recombinant p22 phox and incubated for 60 min. with GST-p47 phox -SH3 fusion proteins (0.5 μg) bound to glutathione-Sepharose beads and analyzed as described; after SDS-PAGE, Sepharose-bound proteins were analyzed by immunoblotting with anti-p22 phox antibody; controls included blotting of recombinant p22 phox lysate (5×10 3 cell equivalents) alone (p22) and bound complexes detected without competing PR-peptides (−); concentrations of competing peptides defined above each blot are indicated below the blots). Using this binding assay, analysis of the inhibition by PR-14, PR-15, PR-16, PR-19, and PR-23 revealed the importance of the COOH-terminal region of PR-26 in SH3 binding ( FIG. 21 ; inhibition by PR-19 or PR-23, conducted as in FIG. 20 ) ( FIG. 22 ; comparison of inhibitory activities of smaller peptides at 25 μM). These data not only supported the hypothesis that PR-39 blocks the interaction between p47 phox and p22 phox , but also indicated that the main structural motif involved in the interaction between PR39 and SH3 domains of p47 phox was in the central segment (PR-16) of PR-39. This 16-residue segment contains structural elements compatible with consensus features of both classes of SH3 peptide ligands (Feng et al., 1994; Lim et al.,1994).
Two sequences within PR-16, RPPPFFP (Sequence ID No.8) and PPRLPPRI (Sequence ID No. 9), conform to consensus sequences for either Class I (+) and Class II (−) binding orientations, X 1 pX 2 PpX 3 P and X 3′ PpX 2′ PpX 1′ , respectively (upper-case denotes critical contact residues, P denotes proline, and X 1 or X 1′ favor arginine residues). Since PR-23 inhibits better than PR-19, a Class II binding orientation appears likely. However, because PR-19 had greater inhibitory activity in the cell-free assay but was less potent in blocking the interaction of p47 phox SH3 domains with p22 phox when compared to PR-23, the polybasic motif of the amino-terminus of PR-26 also represents a separate important component of oxidase inhibition. This observation is supported by studies showing that several other cationic peptides effectively inhibit NADPH oxidase, including peptides derived from p47 phox (Joseph et al., 1994). Thus, critical regions at both ends of PR-26 have been defined based on dramatic losses of function seen with the deleted forms, PR-19 and PR-23.
The polybasic motif at the amino-terminus of PR-26 and PR-39, in addition to their overall amphiphatic character, may have a role in promoting internalization of these inhibitory peptides, since similar structural properties are thought to enable internalization of various synthetic peptides designed for intracellular targets (Derossi et al., 1994; Mann et al., 1994; Fawell et al., 1994; Vellette et al., 1994; Taffs et al., 1992). PR-39 uptake may involve an active endocytic process or direct membrane lipid interactions, since this peptide binds and induces conductance changes in pure lipid bilayers (Cabiaux et al., 1992).
PR-39 is the first naturally occurring down regulator of phagocyte NADPH oxidase identified that interferes with assembly of this enzyme by binding to p47 phox . Little is known about the mechanisms governing respiratory burst kinetics, although models based on a continuous cycling of cytosolic components are consistent with the direct inhibitory effects of PR-39 on oxidase component interactions. The paradoxical finding of a neutrophil peptide possessing both antibacterial and oxidase inhibitory activities is intriguing, since a switch from oxygen-dependent to oxygen-independent bactericidal mechanisms by an accumulation of this peptide within inflammatory sites could serve several important functions.
PR-39, which has a well-documented role as an antibacterial peptide, might have several roles in tissue repair by directly inhibiting NADPH oxidase activity and limiting related proinflammatory responses, while also affecting gene expression patterns that promote wound healing (Gallo et al., 1994). Furthermore, since reactive oxygen intermediates have also been shown to function as second messengers that can regulate gene expression (Schreck et al., 1991), PR-39 may indirectly influence gene expression patterns related to oxidative stress. These opposing activities of PR-39 illustrate a fine balance required in host defense mechanisms: antibacterial activity is necessary to control microbial pathogens and oxidase inhibitory activity is important for restricting tissue damage caused by excessive oxygen radicals generated by NADPH oxidase. In the case of PR-39, one peptide possesses both activities. These findings suggest a mechanism for interaction between oxidative and nonoxidative antimicrobial systems of neutrophils and may serve as a basis for design of drugs effective against production of oxidants in chronic or acute inflammatory disease states.
REFERENCES
The following references are incorporated by reference herein.
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This is a continuation of application Ser. No. 07/780,276 filed on Oct. 18, 1991, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a robot device for a piled-package type double twister and, more specifically, to a robot device for a piled-package type double twister capable of automatically carrying out operations for feed package changing, yarn end finding, threading, doffing and yarn fastening.
RELATED ART STATEMENT
A double twister has a plurality of twisting units arranged in a row. Each twisting unit has a spindle supporting a feed package. A yarn unwound from the feed package and threaded through the bore of the spindle is double-twisted and the double-twisted yarn is taken up on a bobbin supported on a cradle in a take-up package. When all the yarn of the feed package is taken up on the bobbin in a full take-up package and an empty bobbin is left on the spindle, a feed package changing procedure must be carried out, in which the empty bobbin is removed from the spindle and a full feed package is put on the spindle (package changing), the yarn end of the full feed package is pulled out from the full feed package (yarn end finding), the yarn is threaded through the spindle (threading), the full take-up package is removed from the cradle and an empty take-up bobbin is put on the cradle (doffing), and the leading end of the yarn unwound from the feed package is fastened to the take-up bobbin (yarn fastening).
The feed package changing procedure, however, is very troublesome. The applicant of the present application has previously proposed a robot device capable of automatically carrying out the feed package changing procedure in Japanese Patent Provisional Publication No. Hei 2-243470. This robot device travels along the row of the twisting units, stops at a position corresponding to a twisting unit indicated by lighting a pilot lamp, detects if the feed package has been exhausted, carries out the feed package changing procedure if the feed package has been exhausted or advances without carrying out the feed package changing procedure if the feed package has not been exhausted.
A double-package type double twister doubles and double-twists yarns unwound from two feed packages of the same size supported one over the other on a spindle. If the two yarns unwound from the two feed packages differ from each other in yarn tension during the doubling and double-twisting operation, it is possible that one of the two feed packages is exhausted before the other. If one of the feed packages is not exhausted, a predetermined quantity of yarn is wound on the take-up package and hence the feed package changing procedure may be carried out.
However, in applying the robot device to a double-package type double twister, it is difficult to detect the exhaustion of the feed packages supported one over the other on the spindle and hence it is impossible to carry out the feed package changing procedure efficiently.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a robot device capable of readily detecting the exhaustion of two feed packages supported one over the other on a spindle and of efficiently carrying out the feed package changing procedure.
It is another object of the present invention to provide a yarn end finding device for a double-twister robot device capable of avoiding pulling out excessive yarns in finding yarn ends from feed packages.
It is still another object of the present invention to provide a robot device for a double twister capable of threading of feed packages supported on a spindle provided with a tension ball.
Other objects of the present invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification.
To achieve the object, the present device provides a robot device for a piled-package type double twister, capable of detecting the condition of a pilot lamp for indicating yarn breakage, provided in a double-twisting unit which unwinds yarns from two feed packages placed one over the other, twist the yarns, winds the twisted yarn, of starting a feed package changing operation when the take-up package has a predetermined size, of continuing the feed package changing operation if a sensor for detecting the exhaustion of the feed packages detects yarn at least on one of the two feed packages, and of returning the feed packages to their positions and terminating the feed package changing operation if both the feed packages have yarns.
The robot device detects the lighted pilot lamp, and starts the feed package changing operation if the take-up package has a predetermined size. During the feed package changing operation, the sensor provides a signal indicating the condition of the feed packages. If the signal indicates that at least one of the feed packages has been exhausted, the feed package changing operation is continued. If the signal indicates that both the feed packages have yarns, the feed package is returned to their positions and the feed package changing operation is terminated.
The detection of the condition of the two feed packages during the feed package changing operation facilitates detecting the exhaustion of each of the two packages. Since the feed package changing operation is continued if at least one of the feed packages has been exhausted, and the feed packages are returned to their positions and the feed package changing operation is terminated if both the feed packages have yarns, the feed package changing operation can efficiently be carried out.
To achieve the another object, the present invention provides a yarn end finding device for a robot device of a double-twister, having a suction nozzle for sucking the leading ends of yarns of feed packages wound around a top cap provided on top of a tubular adapter supporting the feed packages, characterized in that the suction nozzle is provided with a sensor for detecting the yarns sucked into the suction nozzle, and a gripping device that is actuated to grip the yarns in response to a detection signal provided by the sensor upon the detection of the yarns.
To achieve the still another object the present invention provides a robot device for a double twister, having an operating arm for threading the yarns of feed packages supported on a spindle of the double twister, characterized in that the operating arm is provided with a ball holding unit for attracting a steel ball mounted on the upper end of a top cap for the feed packages during threading operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view of a robot device in a preferred embodiment according to the present invention;
FIG. 2 is a side view of assistance in explaining a manner of detecting the exhaustion of two piled feed packages;
FIG. 3 is another side view of the robot device shown in FIG. 2;
FIG. 4 is a side view showing a yarn end finding device of a robot device for a double-twister;
FIG. 5 is a flow chart of a yarn end finding procedure to be executed by the device shown in FIG. 4;
FIG. 6 is a sectional view of a double-twisting spindle unit;
FIG. 7 is a side view of a robot device in a preferred embodiment according to the present invention for a double-twister;
FIG. 8 is a side view of a ball holder located at the operating position;
FIG. 9 is a side view of the ball holder located at the standby position during the threading operation;
FIG. 10 is a side view of assistance in explaining an operation for returning a steel ball to a top cap;
FIG. 11 is a side view showing a bobbin stocker in an embodiment according to the present invention;
FIG. 12 is a front view of the bobbin stocker for illustrating a supporting state thereof;
FIG. 13 is a side view of a yarn end finding device in a preferred embodiment according to the present invention;
FIG. 14 is an enlarged plan view of the yarn end finding device of FIG. 13;
FIG. 15 is a side view of the yarn end finding device, in which a suction nozzle is advanced to an operating position;
FIG. 16 is a side view of the yarn end finding device, in which a take-up package is rotated in the reverse direction and the suction nozzle is in action; and
FIG. 17 is a side view of the yarn end finding device, in which the suction nozzle is returned to a standby position to complete the yarn end finding operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present device will be described hereinafter with reference to the accompanying drawings.
Referring to FIG. 1, indicated at 1 is one of a plurality of double-twisting units of a double twister. The double-twisting unit 1 has a spindle supporting two feed packages 2 (2a and 2b) one over the other, and a cradle 5 supporting a take-up bobbin 4 in a horizontal position. Yarns Y unwound from the feed packages 2 are threaded through the bore of the spindle 3 for double-twisting. The twisted yarn travels upward and is taken up in a take-up package 7 on the take-up bobbin 4 driven for rotation by a rotary drum 6. The two feed packages 2 are mounted one over the other on a tubular adapter 2c with a cuplike yarn guide 2d interposed therebetween to guide the yarn Y unwound from the lower feed package 2b. The yarn guide 2d is formed by bending fine resin wires.
A snail wire 8 for guiding the twisted yarn Y, a drop wire 9 for detecting yarn breakage, a yarn guide roller 10, and a feed roller 11 for delivering the twisted yarn Y to the take-up package 7 are arranged in that order above the feed packages 2. The drop wire 9 is set against the twisted yarn Y. If both the two feed packages 2 are exhausted or the twisted yarn Y is broken, the drop wire 9 drops to turn on a switch 12 disposed near the lower end thereof. Then, a cylinder actuator is actuated to raise the cradle 5 to a doffing position and a pilot lamp 14 disposed at an upper front position on the double-twisting unit 1 is turned on.
A feed package conveyor 16 for conveying sets of feed packages each of two feed packages put one over the other on a tray 15 is extended in front of the spindles 3 along the double-twisting units 1. A full package conveyor 17 for conveying full packages 7 removed from the cradles 5 is extended behind the rotary drums 6 along the double-twisting units 1. A bobbin stocker 18 is disposed at a front upper position on the double-twisting unit 1, and a plurality of take-up bobbins 4 are reserved in the bobbin stocker 18. A pedal 19 is disposed at a front lower position on the double-twisting unit 1. The spindle 3 is braked to a stop when the pedal 19 is depressed to a first position, and threading compressed air is supplied to the spindle 3 when the pedal 19 is depressed to a second position.
A robot device 20 for a feed package changing operation and the associated operations travels along the double-twisting units 1. Wheels 22 held on the robot device 20 roll along rails 21 extended along the front upper portions and the front lower portions of the double-twisting units 1.
The robot device 20 is provided at its upper portion with a sensor 23 for detecting the lighted pilot lamps 14 of the double-twisting units 1, and at a position below the sensor 23 with a sensor 24 for detecting the size of a take-up package 7 held at the doffing position. Upon the detection of the lighted pilot lamp 14, the robot device 20 stops at a position corresponding to the double-twisting unit 1 indicated by the lighted pilot lamp 14 and detects the size of the take-up package. The robot device starts the feed package changing procedure including a series of operations from a feed package changing operation to a yarn fastening operation if the take-up package 7 has a predetermined size. The robot device advances without carrying out the feed package changing procedure if the size of the take-up package 7 is smaller than the predetermined size.
The robot device 20 is provided with an operating lever 25, and a peg 26 for temporarily supporting two feed packages 2. The operating lever 25 is supported on a horizontal lifting shaft 27. A stopper 28 causes the operating lever 25 to turn counterclockwise, as viewed in FIG. 1, on the lifting shaft 27 as the lifting shaft 27 is lowered to retract the operating lever 25 into the robot device 20. When the lifting shaft 27 is raised, the operating lever 25 is allowed to turn clockwise, as viewed in FIG. 1 on the lifting shaft 27. When the lifting shaft 27 is raised beyond a level corresponding to the stopper 28, the operating lever 25 is held in a horizontal position as shown in FIG. 2. A gripper 29 for gripping the upper end of the adapter 2c supporting the feed packages 2 is supported for longitudinal reciprocation on the operating lever 25. A nozzle 39 for blowing compressed air to remove flies from a space in an inner cover 36 is held on the extremity of the operating lever 25 so as to be directed toward the spindle 3 as shown in FIG. 3 when the operating lever 25 is held in a horizontal position. The nozzle 39 blows compressed air after the empty feed packages 2 have been removed from the spindle 3 and the nozzle 39 has been lowered to its lowermost position as shown in FIG. 3 in transferring the empty feed packages 2 from the spindle 3 to the tray 15 during the execution of the feed package changing procedure. The nozzle 39 is connected by a supply line, not shown, to a compressed air source. A solenoid valve is provided on the supply line to control the supply of compressed air to the nozzle 39.
When it is decided that the take-up package 7 has the predetermined size, the robot device 20 depresses the pedal 19 to the first position with a pressing lever 30 to stop the spindle 3, pushes back the snail wire 8 with a pushing member, not shown, held on the front portion of the operating lever 25, pushes up the drop wire 9 so that the drop wire 9 is attracted to a magnet 31, and then operates the gripper 29 supported on the operating lever 25 for the feed package changing operation. In changing the feed package, two full feed packages 2 supported on the tray 15 placed on the feed package conveyor 16 is transferred from the tray 15 to the peg 26, the exhausted feed packages 2 are transferred from the spindle 3 to the tray 15, and then the full feed packages 2 are transferred from the peg 26 to the spindle 3. The robot device 20 is provided with two sensors 32a and 32b for detecting the exhaustion of the two feed packages 2 removed from the spindle 3 during the feed package changing operation. When the gripper 29 holding the feed packages 2 removed from the spindle 3 reaches a position above the tray 15, the feed packages 2 are disposed opposite to the detectors 32a and 32b, respectively. The leading ends of the yarns of the full feed packages 2a and 2b mounted on the tray 15 are picked up and inserted in the bore of the adapter 2c beforehand.
When the exhaustion of at least one of the feed packages 2a and 2b is detected during the feed package changing operation, the feed package changing operation is continued. After the feed package changing operation has been completed, the pedal 19 is depressed to the second position with the pressing lever 30 to supply compressed air to pass the leading ends of the yarns inserted in the bore of the adapter 2c through the bore of the spindle 3 for threading so that the leading ends of the yarns are blown upward outside the spindle 3. At the same time, the cradle 5 is expanded with an operating lever 33 to transfer the full take-up package 7 from the cradle 5 to the take-up package conveyor 17, a bobbin gripper 34 picks up one of the bobbins 4 from the bobbin stocker 18 and puts the bobbin 4 on the cradle 5 to complete the doffing operation. The operating lever 25 threads the leading ends of the yarns through the snail wire 8, the yarn guide roller 10 and the feed roller 11, and fastens the leading ends of the yarns to the bobbin 4 held on the cradle 5.
After the series of operations has been completed, the operating lever 33 lowers the cradle 5 to bring the bobbin 4 into contact with the rotary drum 6 to start winding the twisted yarn, the pressing lever 30 is retracted to release the pedal 19 so that the spindle 3 is able to rotate, the drop wire 9 is set against the twisted yarn, the operating lever 25 is retracted, and then the robot device 20 starts traveling.
On the other hand, if the sensors 32a and 32b detects that both the feed packages 2a and 2b have yarns, the robot device 20 returns the feed packages 2 onto the spindle 3, returns the full feed packages 2 supported on the peg 26 onto the tray 15, interrupts the feed package changing operation, retracts the operating lever 25, and then starts traveling. The operation of the robot 20 device is controlled by a controller included in the robot device 20.
The operation of the embodiment will be described hereinafter.
If the twisted yarn being taken up by the double-twisting unit 1 breaks, the drop wire 9 drops to turn on the switch 12 and, consequently, the cradle 5 is raised to the doffing position by the cylinder actuator 13 and the pilot lump 14 is lighted. Then, the robot device 20 traveling along the double-twisting units 1 detects the lighted pilot lamp 14 by the sensor 23 and stops at a position corresponding to the double-twisting unit 1 indicated by the lighted pilot lamp 14 and detects the size of the take-up package 7 by the sensor 24.
If the size of the take-up package 7 is smaller than the predetermined size, the robot device 20 advances without carrying out the feed package changing operation. If the size of the take-up package 7 is equal to the predetermined size, the robot starts the feed package changing operation.
First, the pressing lever 30 depresses the pedal 19 to the first position to stop the spindle 3, the lifting shaft 27 is raised to extend the operating lever 25 horizontally and the gripper 29 is moved along the operating lever 25 simultaneously, the gripper 29 transfers the full feed packages 2 from the tray 15 placed on the feed package conveyor 16 to the peg 26, and then the gripper 29 transfers the exhausted feed packages 2 from the spindle 3 to the tray 15.
After the exhausted feed packages 2 have been removed from the spindle 3, compressed air is blow from the nozzle 39 into the interior of the inner cover 36 toward the spindle 3 to blow out fly accumulated in the inner cover 36 through openings 40 formed in the inner cover 36 and an outer cover 38. Fly can effectively removed from the spindle 3 because compressed air is blown from the nozzle 39 when the spindle 3 is unloaded and the nozzle 39 is at its lowermost position, namely, at a position closest to the spindle 3.
When the exhausted feed packages 2 are positioned opposite to the sensors 32a and 32b, respectively, the sensors 32a and 32b detects the exhaustion of the feed packages 2a and 2b. If at least one of the feed packages 2a and 2b has been exhausted, the robot device 20 continues the feed package changing operation to place the feed packages 2a and 2b on the tray 15, and then transfers the full feed packages 2 from the peg 26 to the spindle 3.
After the feed package changing operation has thus been completed, the pressing lever 30 depresses the pedal 19 to the second position to blow compressed air for threading, the operating lever 33 expands the cradle 5 to deliver the full take-up package 7 to the conveyor 17, the bobbin gripper 34 takes out the bobbin 4 from the bobbin stocker 18 and puts the bobbin 4 on the cradle 5 to complete the doffing operation. The operating lever 25 passes the yarns through the snail wire 8 and fastens the leading ends of the yarns to the bobbin 4 held by the cradle 5 to complete the threading operation.
After the series of operations has been completed, the operating lever 25 of the robot device 20 lowers the cradle 5 to bring the bobbin 4 into contact with the rotary drum 6, the pressing lever 30 releases the pedal 19 to enable the spindle 3 to rotate, the drop wire 9 is set against the yarns Y, the operating lever 25 is retracted, and then the robot device 20 starts traveling again.
If the sensors 32a and 32b detect yarns on both the feed packages 2a and 2b during the feed package changing operation, the robot device 20 returns the feed packages 2 onto the spindle 3, returns the full feed packages 2 from the peg 26 to the tray 15, retracts the operating lever 25, and then starts traveling again omitting the following steps of the feed package changing operation.
The twisted yarn is broken in the double-twisting unit 1 indicated by the lighted pilot lamp 14 and for which the robot has not carried out the feed package changing operation, the operator pieces together the yarns unwound from the feed packages 2 and the twisted yarn unwound from the take-up package 7, and then starts the double-twisting and winding operation of the same double-twisting unit 1.
As is apparent from the foregoing description, according to the present device, the exhaustion of the feed packages can readily be detected because the exhaustion of the feed packages is detected during the feed package changing operation, and the feed package changing operation can efficiently be achieved because the feed package changing operation is continued if at least one of the feed packages has been exhausted, and the feed package changing operation is interrupted and the feed packages are returned onto the spindle if both the feed packages have yarns.
FIG. 4 shows the general construction of a yarn end finding device for a double-twisting robot device.
Feed packages Pu and Pd are put on an adapter 101 one over the other. The adapter 101 supporting the feed packages Pu and Pd is put on a peg 105 supported on a swing arm 104. The swing arm 104 swings to transport the adapter 101 supporting the feed packages Pu and Pd from a feed package supplying position to a yarn end finding position A shown in FIG. 4. A suction pipe 107 is set upright on a table 106 placed at the yarn end finding position A, a suction arm 108 is supported at one end for swing motion in a vertical plane on the upper end of the suction pipe 107, and a suction nozzle 103 is provided on the other end of the suction arm 108. The suction arm 108 is turned in a vertical plane by a cylinder actuator 109 supported on the suction pipe 107 between a working position indicated by continuous lines where the suction nozzle 103 is put on the top cap 102 provided on top of the adapter 101 and a standby position indicated by alternate long and short dash lines 103a. The feed packages Pu and Pd can be turned together with the peg 105 in a direction opposite the direction of winding of coils B of yarns wound around the top cap 102.
The suction nozzle 103 is provided with a sensor 110, such as a photoelectric sensor, for detecting yarns sucked into the suction nozzle 103, and a gripping device 111, which resembles a shutter, for closing the suction nozzle 103 and gripping the yarns upon the detection of the yarns by the sensor 110.
As soon as the feed packages Pu and Pd have been transported to the yarn end finding position A as shown in FIG. 4 by turning the swing arm 104, the suction arm 108 is turned from the position indicated by alternate long and short dash lines to the position indicated by continuous lines to put the suction nozzle 103 on the top cap 102 attached to the upper end of the adapter 101, and then the feed packages Pu and Pd are rotated. Then, the coils B wound around the top cap 102 are unwound and the yarns are sucked into the suction nozzle 103. Upon the detection of the yarns by the sensor 110, the gripping device 111 is actuated to grip the yarns, so that the yarns are not pulled any further.
In some cases, the coils B may not completely be unwound before the yarns are gripped by the gripping device 111. Therefore, a coil unwinding procedure is executed, in which the suction nozzle 103 is raised to the position indicated by the alternate long and short dash line 103a and, at the same time, the gripping device 111 releases the yarns, the suction nozzle 103 is put on the top cap 102 again, and then the yarns are gripped by the gripping device 111.
The yarn end finding procedure is repeated several times to unwind the coils B completely to extend the yarn ends Yu and Yd directly between the feed packages Pu and Pd, and the suction nozzle 103.
The foregoing yarn end finding operation will be described with reference to FIG. 5.
The yarn end finding operation is started in step 115. In step 116, the feed packages Pu and Pd are rotated, the gripping device 111 is opened and the suction nozzle starts sucking the yarn ends. In step 117, a query is made to see if the sensor 110 has detected the yarn ends. If the response in step 117 is affirmative, the gripping device 111 is actuated in step 118 to grip the yarn ends, and then the suction nozzle 103 is raised in step 119. After disengaging the gripping device 111 to release the yarn ends in step 120, the suction nozzle 103 is put on the top cap 120 again in step 121. Thus, the yarn ends pulled up as the suction nozzle 103 is raised is sucked into the suction nozzle 103, so that the coils B are unwound. A query is made in step 122 to see if the suction nozzle 103 has been raised predetermined times. If the response in step 122 is negative, the procedure returns to step 118. If the response in step 122 is affirmative, the yarn end pulling procedure is terminated. If the response in step 117 is negative, a query is made in step 124 to see if a time for yarn end pulling operation has elapsed. If the response in step 124 is affirmative, an alarm is given by appropriate means to inform the operator of failure in the yarn end finding operation in step 125.
Thus, the excessive unwinding of the yarns can be avoided by gripping the yarn ends upon the detection of the yarn ends.
After the completion of the yarn end finding operation, the feed packages Pu and Pd are transported to the double twister, not shown, the yarn ends Yu and Yd extending between the suction nozzle 103, and the feed packages Pu and Pd are cut, and then the yarn ends Yu and Yd are inserted in the bore of the adapter 101 for threading.
Although the device has been described as applied to finding the yarn ends of two feed packages supported one over the other on the adapter, the present device is applicable to finding the yarn end of a single feed package.
As is apparent from the foregoing description, the excessive unwinding of yarns from feed packages can be avoided by the cooperative operation of the sensor and the gripping device provided on the suction nozzle to grip the yarn ends upon the detection of the yarn ends by the sensor.
Incidentally, in some spindle unit, a conical recess 219 is formed in the upper end of the top cap 216, and a steel ball 220, i.e., a tension ball, is placed in the conical recess 219 as shown in FIG. 6 to suppress tension variation and to prevent kinking while the yarns are unwound from the feed packages. In threading the yarns of the feed packages 202 through the spindle of such a construction, the steel ball 220 hinders the movement of the yarns and hence it is difficult for the conventional robot to carry out the threading operation.
Accordingly, it is another object of the present invention to provide a robot device for a double twister capable of threading yarns of feed packages supported on a spindle provided with a tension ball.
To achieve the object provides a robot device for a double twister, having an operating arm for threading the yarns of feed packages supported on a spindle of the double twister, characterized in that the operating arm is provided with a ball holding unit for attracting a steel ball mounted on the upper end of a top cap for the feed packages during threading operation.
In the threading operation, the steel ball provided on the top cap is separated from the top cap and held by the ball holding unit of the operating arm to facilitate the threading operation.
A preferred embodiment of the robot device will be described hereinafter with reference to the accompanying drawings.
Referring to FIG. 7, in which parts like or corresponding to those described with reference to FIG. 6 are denoted by the same reference characters and the description thereof will be omitted, a double twister 221 is provided with a plurality of twisting and winding units arranged in a row. Each twisting and winding unit is provided with a spindle 201 similar to the foregoing spindle 201. A conveyor 223 for conveying feed packages 202 mounted on trays 222 is in front of the twisting and winding units along the same. A robot device 224 travels along the front side of the conveyor 223.
The robot device 224 has an elongate operating arm 226 pivotally supported on a lifting shaft 225. When the lifting shaft 225 is lowered to its lowermost position, the front portion of the operating arm 226 engages a stopper 227 and the operating arm 226 is retracted into the body of the robot 224 so that the operating arm 226 may not interfere with the double twister while the robot 224 travels along the double twister. When the front portion of the operating arm 226 is not in engagement with the stopper 227, the operating arm 226 is held in a horizontal position as shown in FIG. 7 and moves vertically together with the lifting shaft 225.
The robot 224 is provided with a storage peg 228 for temporarily storing full feed packages 202A conveyed to the robot device 224 by the conveyor 223, a suction nozzle 229 for unwinding yarn ends wound around the upper end of a top cap 216 combined with the full feed packages 202A by suction, and a cutter 230 for cutting the yarn ends YX extending between the full feed packages 202A put on the spindle 201 and the suction nozzle 229 in threading the yarns of the full feed packages 202A.
A gripper 231 for gripping the top cap 216 combined with feed packages (either full feed packages or exhausted feed packages) is supported on the operating arm 226 for longitudinal movement along the operating arm 226. As shown in FIGS. 7 and 8, a yarn holder 232 for holding part of the yarn ends YX extended between the full feed packages 202A and the suction nozzle 229 is provided above the gripper 231. A blowing nozzle 233 for blowing compressed air into the yarn passage 215 of the top cap 216 combined with the full feed packages 202A for threading is provided above the yarn holder 232. A ball holder 234 for attracting the steel ball 220, i.e., a tension ball, placed in a recess 219 formed in the upper end of the top cap 216 is provided under the yarn holder 232.
As shown in FIGS. 8, 9 and 10, the ball holder 234 comprises a frame 235 having an L-shaped cross section, and a permanent magnet 236 attached to the frame 235. A pneumatic actuator 237 is attached to the base end of the yarn holder 232 to slide the ball holder 234 along the lower surface of the yarn holder 232. When the ball holder 234 is moved to its operating position by the pneumatic actuator 237, the permanent magnet 236 is located directly below the blowing nozzle 233 as shown in FIG. 8. When the ball holder 234 is retracted to its standby position, the permanent magnet 236 is located at a position near the base end of the yarn holder 232 and separated from the blowing nozzle 233.
The operation of the embodiment will be described hereinafter.
In threading the yarns, the full feed packages 202A are transferred from the tray 222 placed on the conveyor 223 to the storage peg 228 of the robot 224 by the combination of the vertical movement of the operating arm 226, the movement of the gripper 231 along the operating arm 226 and gripping and releasing actions of the gripper 231, and then the suction nozzle 229 unwinds the yarn ends wound around the top cap 216 combined with the full feed packages 202A supported on the storage peg 228 by suction. While the yarn ends are being unwound from the top cap 216, exhausted feed packages 202B are transferred from the spindle 201 to the tray 222 by operations similar to those for transferring the full feed packages 202A from the tray 222 to the storage peg 228.
Then, the gripper 231 is moved to put part of the yarn ends YX extending between the full feed packages 202A and the suction nozzle 229 on the yarn holder 232 and to transfer the full feed packages 202A from the storage peg 228 to the spindle 201 as shown in FIG. 7.
Then, as shown in FIG. 8, the ball holder 234 is moved to the operating position by the pneumatic actuator 234 as shown in FIG. 8, and then the operating arm 226 is lowered to locate the ball holder 234 near the top cap 216 combined with the feed packages 202 so that the steel ball 220 is attracted to the permanent magnet 236. Subsequently, the operating arm 226 is raised to remove the steel ball 220 from the recess 219 of the top cap 216, the ball holder 234 is moved to the standby position by the pneumatic actuator 237 as shown in FIG. 9, and then the operating arm 226 is lowered to locate the blowing nozzle 233 near the top cap 216. Then, compressed air is blown into the air passage 209 of the spindle 201 to generate a suction air current in the yarn passage 208, compressed air is blown from the blowing nozzle 233 into the yarn passage 215 of the top cap 216 and, at the same time, the yarn ends YX extending between the full feed packages 202A and the suction nozzle 229 is cut by the cutter 230. Consequently, the yarn ends YX are blown through the upper end of the top cap 216 into the top cap 216, pass through the yarn passages 215, 210 and 208, are deflected upward by a deflecting plate 217 and are blown upward through the space 218 between the stationary cylinder 206 and the balloon control cylinder 207 to complete threading.
After the threading operation has thus been completed, the ball holder 234 is moved to the operating position as shown in FIG. 8, the operating arm 226 is lowered to put the steel ball 220 into the recess 219 of the top cap 216, and then the ball holder 234 is returned to the standby position as shown in FIG. 10, leaving the steel ball 220 in the recess 219 of the top cap 216.
The permanent magnet 236 employed in this embodiment for holding the steel ball 220 may be substituted by a suction cup.
As is apparent from the foregoing description, according to the present device, the steel ball provided in the top cap is held by the ball holder provided on the operating arm to remove the steel ball from the top cap during the threading operation and it is therefore possible to thread the yarns of the feed packages through the spindle even if the spindle is provided with a tension ball.
FIG. 11 shows a bobbin stocker 321 in a preferred embodiment according to the present invention.
The bobbin stocker 321 has stopping members 322 for holding a bobbin 309 at a predetermined position on a bobbin extracting unit 313 and capable of bending in a vertical plane.
The stopping member 322 comprises a round bar 323, and a coil spring 324 for supporting the bar 323 on a bottom plate 314.
The bar 323 is formed of an ABS resin by molding and has a round extremity. The length of the bar 323 is far greater than the diameter of the bobbin 309. The coil spring 324 has one end attached to the lower surface of the bottom plate 314 and the other end embedded in the bar 323 by a predetermined depth.
The bar 323 is extended along the extension of the inclined bottom plate 314 to hold the bobbin 309 to be extracted so as to extend across a path A along which a gripper moves. When the gripper moving upward or downward engages the bar 323, the coil spring 324 bends resiliently on its base end 325, and the coil spring 324 restores its bobbin supporting position indicated by continuous lines in FIG. 11 after the bar 323 has been disengaged from the gripper.
In this embodiment, the bobbin stockers 321 respectively for the spindles are fixed to a longitudinal frame 326 extended along the spindles arranged in a row as shown in FIG. 12 at predetermined intervals so that the middle of each bobbin stocker 321 is located at a position corresponding to the axis B of the corresponding spindle. The opposite ends of the longitudinal frame 326 are fastened to the main frames 327 of a double twister.
The operation of the bobbin stocker in this embodiment will be described hereinafter.
Empty bobbins 309 for take-up packages are arranged on the bottom plate 314 of the bobbin stocker 321. The endmost bobbin 309 is held between the stopping members 322 of the extracting unit 313, and the free ends 319 of side plates 318.
In supplying the bobbin 309 to the double twister by the robot device, the bobbin supply arm moves downward, the gripper provided on the extremity of the bobbin supply arm grips the endmost bobbin 309 and moves to the standby position. The stopping members 322 holding the bobbin 309 are bent downward by the gripper to enable the gripper to grip the bobbin 309.
When the bobbin supply arm returns to its upper position past the bobbin stocker 321 after supplying the bobbin 309 to the cradle, in some cases, the extremity of the bobbin supply arm collides against the bars 323. In such a case, the coil springs 324 are bent to allow the bars 323 to move upward, so that shocks of collision is reduced.
Even if the bars 323 are bent upward, the bars 323 are returned to the bobbin holding position by the resilience of the coil springs 342 to hold the bobbins 309 stored on the bottom plate 314 to prepare for the next bobbin transfer operation.
Since the bars 323 are held by the coil springs 324 on the bottom plate 314 so as to be turned upward and downward, the bars 323 are able to be turned upward by the gripper when the gripper collides against the bars 323 as it moves upward, so that the bars 323 are not damaged. Since the number of the components of the stopper is less than that of the components of the conventional stopper, the stopper can be manufactured at a reduced cost and requires less work for assembly.
Since the bobbin stockers 321 for the spindles, differing from the bobbin stockers of an automatic winder, are formed in an integral unit, the respective positions of the bobbin stockers 321 need not individually be adjusted and hence the frames of the double twister can readily be assembled.
Although the stopping member 322 employed in this embodiment comprises the bar 323 and the coil spring 324, the stopping member 322 may be a single member having a high resilience attached to the bottom plate 314 (bobbin extracting unit 313).
As is apparent from the foregoing description, the device has the following excellent effects.
Since the bobbin extracting unit is provided with the stopping members capable of holding bobbins at predetermined positions and of bending upward and downward, the bobbin extracting unit is never damaged even if the bobbin supply arm or the like comes into contact therewith from under the same, components can be reduced and the cost is reduced.
Next, other embodiment of the present invention will be described hereinafter.
If the yarn is broken while the same is being taken up on a double twister, the broken yarn end is wound around the surface of the yarn layers of the take-up package. Accordingly, the broken yarn end adhering to the surface of the yarn layers of the take-up package needs to be found out to piece together the broken yarn end taken out from the take-up package and the broken yarn end taken out from the feed package.
It has been a practice that the operator finds out the broken yarn end on the take-up package, which, however, require time and labor. The winder is provided with a yarn end finding device which reverses the rotary drum, which is driven individually, of each winding unit and picks up the yarn end from the surface of a take-up package by a suction nozzle by suction. However, the technique of finding a yarn end for the winder cannot be applied without modification to a double twister because the rotary drums of the winding units of the double twister are mounted fixedly to a common drive shaft and hence the rotary drums cannot individually be reversed. Accordingly, a special driving device is necessary for driving each take-up package in a direction reverse to the winding direction, namely, in an unwinding direction, which makes the construction of the double twister complicated and increases the cost of the same.
Accordingly, this embodiment provides a yarn end finding device for a double twister, simple in construction and capable of readily finding a yarn end from the surface of a take-up package.
The present invention provides a yarn end finding device for a double twister, comprising a suction nozzle capable of being moved toward and away from a take-up package on the double twister and of exerting suction on the surface yarn layer of the take-up package, and a roller supported on the suction nozzle, capable of being inserted between the take-up package and a rotary drum for driving the take-up package, and of being driven for rotation by the rotary drum to rotate the take-up package in a direction reverse to a winding direction.
In finding the yarn end, the suction nozzle is advanced toward the take-up package so that the roller is inserted between the take-up package and the rotary drum. Then the rotation of the rotary drum is transmitted through the roller to the take-up package, so that the take-up package is rotated in a direction reverse to the winding direction, namely, an unwinding direction to facilitate finding the yarn end by the suction nozzle. Since the take-up package is driven for rotation in the unwinding direction through the roller by the rotary drum, any special driving device is unnecessary, and the yarn end finding device is simple in construction and does not entail increase in the cost.
Referring to FIG. 13, A double twister 401 has a plurality of twisting and winding units 402 arranged in a row. Each twisting and winding unit 402 has a spindle 403 disposed in a vertical position in the lower section thereof, and a rotary drum 404 disposed in a horizontal position in the upper section thereof and driven for rotation by a common drive shaft.
A feed package 406 is placed within a stationary cylinder 405 supported stationarily on the spindle 403. A yarn Y unwound form the feed package 406 is guided through the upper end of the spindle 403 into the bore of the spindle 403 and is pulled out in a radial direction from the spindle 403. The yarn Y is twisted when the spindle 403 spins. The yarn Y form a balloon between the spindle 403 and a snail wire 407 disposed above the spindle 403. The yarn y travels upward through a guide roller 408 and a feed roller 409, and is taken-up on a take-up package 411 supported on a cradle 410, held in contact with the rotary drum 404 by gravity and driven for rotation by the rotary drum 404.
In case yarn breakage occurs in the twisting and winding unit 402 of the double twister 401, the broken yarn end on the side of the take-up package 411 is wound around the surface of the take-up package 411. In piecing together the yarn of the take-up package 411 and the yarn end of the feed package 406, a yarn end finding device 412 finds out the yarn end adhering to the surface of the take-up package 411.
Although the yarn end finding device 412 in this embodiment is incorporated into a robot device 413 for a double twister as shown in FIG. 1, each twisting and winding unit 402 may individually be provided with the yarn end finding device 412.
The robot 413 travels along the twisting and winding units 402. Upon the detection of lighted pilot lamp indicating yarn breakage, the robot 413 stops at a position corresponding to the twisting and winding unit indicated by the lighted pilot lamp. The robot 413 is provided with an operating arm for feed package changing operation. The operating arm has no direct relation with the present invention and hence the description of its construction will be omitted.
The robot 413 is provided with a cradle operating lever 414 for vertically turning, expanding and closing the cradle 410 for doffing. The cradle operating lever 414 is employed in the yarn end finding operation. The cradle operating lever 414 has one end pivotally supported on the side wall of the robot 413 and the other end provided with a projection 416 that engages the extremity of the cradle 410 from under the cradle 410.
The yarn end finding device 412 can be advanced toward and retracted away from the take-up package 411 supported by the cradle 410 on the double twister 401. The yarn end finding device 412 comprises, as principal components, a suction nozzle 417 for exerting suction on the surface of the take-up package 411, and a roller 418 supported on the suction nozzle 417 so as to be inserted between the take-up package 411 and the rotary drum 404 and to be driven for rotation by the rotary drum 404 to rotate the take-up package 411 in a direction reverse to a winding direction.
As shown in FIG. 14, the suction nozzle 417 comprises, as principal components, a hollow swing arm 419 pivotally supported on the robot 413, and a nozzle body 421 pivotally joined to the extremity of the swing arm 419 with a hollow joint. A hollow joint 422 connected to the base end of the swing arm 419 is connected to a vacuum source, not shown.
A pneumatic actuator 423 turns the swing arm 419 substantially in a horizontal plane between a standby position on the side of the robot 413, and an operating position near the rotary drum 404. The nozzle body 421 has a shape resembling a funnel expanding toward the free end thereof. The free end of the nozzle body 421 has a width approximately equal to the with of the yarn layer of the take-up package 411, and a suction opening 424 is formed in the free end of the nozzle body 421. In operation, the nozzle body 421 is located with its suction opening 424 under the yarn layer of the take-up package 411.
A frame 425 is attached to one side of the free end of the nozzle body 421, and a roller 418 is supported for rotation in a horizontal position on the frame 425. The nozzle body 421 is translated between the standby position and the operating position where the roller 418 is inserted between the take-up package 411 and the rotary drum 404 by a parallel motion mechanism, not shown.
The operation of the yarn end finding device will be described hereinafter.
When yarn breakage occurs in the twisting and winding unit 402 operating in a state as shown in FIG. 13, the broken end of the yarn on the side of the take-up package 411 is wound around the surface of the take-up package 411. Upon the detection of the lighted pilot lamp indicating the twisting and winding unit 402 in which yarn breakage has occurred, the robot 413 stops at a position corresponding to the same twisting and winding unit 402 to find the broken yarn end in the take-up package 411.
First, the cradle operating lever 414 raises the cradle 410 to separate the take-up package 411 from the rotary drum 404, and the swing arm 419 is turned to shift the suction nozzle 417 from the standby position to the operating position near the take-up package 411; consequently, the roller 418 supported on the frame 425 near the free end of the nozzle body 421 is put on the rotary drum 404 as shown in FIG. 15. Then, the cradle operating lever 414 lowers the cradle 410 to bring the take-up package 411 into contact with the roller 418 as shown in FIG. 16.
The take-up package 411 is rotated in a direction reverse to the winding direction for winding the yarn Y on the take-up package 411, namely, an unwinding direction, through the roller 418 by the rotary drum 404 and air is sucked through the suction opening 424 of the nozzle body 421 disposed near the surface of the take-up package 411, so that the broken yarn end adhering to the surface of the yarn layer of the take-up package 411 can readily be found out.
After the passage of a predetermined time or upon the detection of the broken yarn end by a sensor provided within the nozzle body 421, the cradle operating lever 414 raises the cradle 410. Then, the take-up package 411 stops naturally and the suction nozzle 417 is returned to the standby position together with the yarn end YZ as shown in FIG. 17.
Thus, the take-up package 411 can be rotated in the reverse direction by the rotary drum 404 simply by inserting the roller 418 between the rotary drum 404 and the take-up package 411, and hence any special driving device for rotating the take-up package 411 in the reverse direction is not necessary. Accordingly, the yarn end finding device is simple in construction and can be manufactured at a reduced cost. Since the take-up package 411 is put on the roller 418 provided on the free end of the nozzle body 421, the suction opening 424 can always be located at a predetermined distance from the surface of the take-up package 411 without requiring any locating mechanism regardless of the diameter of the yarn layer of the take-up package 411.
As is apparent from the foregoing description, according to this embodiment, the rotation of the rotary drum is transmitted through the roller to the take-up package to rotate the take-up package in the reverse direction, namely, the unwinding direction, to assist the suction nozzle in finding the yarn end, when the roller is inserted between the take-up package and the rotary drum by advancing the suction nozzle toward the take-up package. Accordingly, the yarn end can readily be found and pulled out from the surface of the yarn layer of the take-up package, any special driving mechanism for rotating the take-up package in the reverse direction is not necessary, and the yarn end finding device can be formed in a simple construction at a reduced cost. | A robot device for a piled-package type double twister, capable of detecting the condition of a pilot lamp for indicating yarn breakage, provided in a double-twisting unit which unwinds yarns from two feed packages placed one over the other, twist the yarns, winds the twisted yarn, of starting a feed package changing operation when the take-up package has a predetermined size, of continuing the feed package changing operation if a sensor for detecting the exhaustion of the feed packages detects yarn at least on one of the two feed packages, and of returning the feed packages to their positions and terminating the feed package changing operation if both the feed packages have yarns. | 3 |
This application claims the benefit of U.S. Provisional Application No. 60/903,699 filed on Feb. 27, 2007, and U.S. Provisional Application No. 60/903,721 filed on Feb. 27, 2007, both of which are incorporated herein by this reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for use with a shallow bore hole under the floor of a drilling rig in which sections of drill pipe are temporarily placed before being connected to the drill assembly, and more particularly to methods and apparatus for supporting drill pipe sections in a house hole adjacent to a drilling rig.
2. Description of the Prior Art
Drilling rigs are designed to drill wells deep into the earth's surface in order to extract materials such as oil, gas, etc. In order to drill effectively a great distance, the drill pipe consists of sections or “joints” of drill pipe or tubing which are continuously attached together at the drill assembly to obtain a pipe having a desired length. Such sections of drill pipe are typically 30 feet in length. In order to attach a new section of drill tubing to the existing pipe being used for the drill, the new section of drill pipe must be in a generally vertical position for attachment. Because of the weight and size of drill pipe sections, each such section of drill pipe requires support in order to be placed in a vertical orientation. In order to prepare a section of drill pipe for attachment, a common solution has been to provide a shallow bore hole adjacent to the much deeper drilling hole in the rig, into which such pipe sections are inserted in a generally vertical orientation prior to installation onto the main shaft of piping. Such shallow holes are commonly referred to as “mouse holes.”
A mouse hole is typically lined with wider piping and used as a convenient location to store the next section of drill pipe. A typical mouse-hole is usually just slightly shallower than a section of pipe. Thus, when a section of pipe is lowered into the mouse-hole, it can rest on the bottom and lean against the walls of the mouse-hole to stay in a generally vertical orientation, with the top portion of the pipe section extending above ground in order to be accessible for removal and attachment to the main drill pipe. Once the drill pipe section is placed in the mouse hole, its position is generally upright and stable, allowing the equipment used to insert pipe section to be allocated to other uses.
Generally pipe is unloaded from a truck or other delivery vehicle and placed on a pipe rack for storage. When a new section of pipe is needed, a crew brings pipe from the pipe rack using a cat line, air hoist or hydraulic winch up to the drilling floor and places it in the mouse-hole.
By placing the new drill pipe section in the mouse hole, it can be prepared for attachment to the main drill pipe while a prior section of pipe is being drilled. The prior section of pipe is drilled into the ground until it reaches a depth where it is ready for the new pipe section to be attached. While this drilling is taking place, the new pipe section is hoisted out of the mouse hole, and maneuvered near the main drill bore in a generally vertical orientation. When the prior pipe section is drilled in far enough, the vertically oriented new pipe section is attached to it, and drilling continues. Under this method, drilling must stop roughly every thirty feet (the length of a typical section of pipe) to allow for the time to add another drill pipe section.
In many cases, this process involves removing the kelley from the prior section chain of drill pipe, and moving the kelley into position over the new pipe section in the mouse-hole. The new pipe section is attached to the kelley, and raised out of the mouse-hole. The bottom of the new pipe section is attached to the end of the prior pipe section of the existing pipe chain. While drilling crews become very efficient in adding pipe sections, the process still takes considerable time, and when repeated multiple times for deep wells, this amount of non-drilling time is significant. Because of the time-consuming nature of adding drill pipe sections, it is desirable to provide methods and apparatus for more efficient and speedy attachment of drill pipe sections.
Existing mouse hole support units are generally designed to be permanently mounted into or below the floor of a drilling rig, above the mouse hole itself. They are not portable. For new installations, it is a simple matter to dig out the mouse hole itself and then install the support unit into the floor of the rig over the mouse hole as the floor and rig is constructed. However, installing such a support unit in an existing drill rig is expensive and cumbersome since it will generally involve partially demolishing or replacing the floor of the drill rig in order to provide proper support for the unit. It is therefore desirable to provide a portable mouse hole pipe support unit, and/or mouse hole pipe support units that may be installed above or on top of an existing floor of a drill rig.
Existing mouse hole support units also suffer from the drawback that they are provided in only one size, such that shims or slips are required in order for these support units to engage a given section of pipe. With these existing units, different shims or slips are required for engaging pipes having different diameters. Such mouse hole support units include a rotatable bowl surrounding an opening through which the pipe section is inserted. The circumference of the opening is designed to be larger than the largest pipe section to be used, and the circumference of the bowl is larger still. As a result, once a pipe section is inserted through the bowl and opening, it is necessary to insert a plurality of shims or slips between the pipe section and the bowl in order to hold the pipe section in place in the bowl before it can be rotated for attachment to the next pipe section.
A typical drill pipe section may have two different diameters: a larger diameter at the ends of the section, and a narrower diameter along the middle portion of the drill pipe. The larger diameter at the end of the drill pipe creates an annular shoulder which can be used to prevent it from moving. The shims or slips are typically inserted adjacent to this annular shoulder to hold the pipe section in place when attaching one section of pipe to another, as described in U.S. Pat. No. 5,351,767. Once this attachment is achieved, the plurality of shims or slips must then be removed from the bowl so that the pipe section(s) may be removed. The insertion and removal of the shims or slips must be repeated for each pipe section that is inserted into the bowl, a process which takes considerable time. Different sizes of slips may be required for pipe section of different diameters. In addition, the slips and the frictional surfaces thereon tend to wear out from being constantly inserted and removed. It is therefore desirable to provide methods and apparatus for securely engaging pipes of different diameters in a mouse hole without the need for separate support shims or slips.
SUMMARY OF THE INVENTION
The present invention provides improved methods and apparatus for supporting and engaging drill pipe in a mouse hole that allows for multiple drill pipe sections or joints to be attached together before being attached to an existing drill string. The present invention is designed to allow for engagement and disengagement of drill pipe sections of various diameters without the need for manually inserting or removing support shims or slips. These features allow for speedy set up and attachment of drill pipe sections during drilling operations. The support unit of the present invention is also portable, and may be retrofitted into an existing drill rig platform.
Embodiments of the present invention allow for the connection of multiple sections of drill pipe in a mouse hole by securing a given section of pipe in the hole and delivering a rotational force to secure that pipe section to another section of drill pipe placed above it over the mouse hole. In some embodiments, the rotational force may be provided by the support unit of the present invention. In alternative embodiments, the rotational force may be provided by an outside source such as an iron roughneck, with the support unit of the present invention holding the drill pipe section in a stationary position as such force is delivered. The unit then allows the connected pipe sections to be lowered and secured so the process can be repeated to connect multiple sections of drill pipe together in the mouse hole. The multiple sections of drill pipe may then be retrieved as a unit, and attached to the pipe string already being used to drill the well. This saves considerable time when extending the length of the main drill pipe string. Instead of attaching a single section of pipe to the main pipe string each time, the present invention allows for a pre-connected set of multiple pipe sections to be attached. Thus, for example, if the set in the mouse hole is made up of three attached pipe sections, the time for drilling the same depth may be speeded up by much as two thirds.
The mouse hole of the present invention is different from standard mouse hole designs. Typically the depth of a mouse hole is slightly shorter than that of one section of pipe. The mouse hole of the present invention is at least twice as deep as such a standard mouse hole, if not deeper, in order to allow enough depth for the insertion of multiple sections of pipe, and to not limit the number of pipe sections that can be connected with the device at one time. Accordingly, the mouse hole should be of a depth to accommodate at least two or more sections of drill pipe. In one embodiment, the mouse hole accommodates three sections of drill pipe. It is to be appreciated that this greater depth is desirable in order to accomplish the connection of multiple sections of pipe together before those sections are removed as a unit from the mouse hole for attachment to the main drill pipe chain.
The support units of the present invention are provided for installation over a mouse hole. A support unit may be mounted above or below the floor of the drill rig surrounding the mouse hole to prevent movement. Embodiments of the support unit include a frame which is positioned above the mouse hole, and an engagement/slip assembly. The engagement assembly is capable of securely engaging a pipe section so that it may be held in place by the support unit. A first pipe section is lowered into the mouse hole and engaged by the assembly, and a second pipe section is then placed adjacent to the first pipe section (end to end). The second pipe may then be rotated using an external source such as an iron roughneck or the like, in order to engage it with the first pipe being held by the support unit in the mouse hole. In some embodiments, the engagement/slip assembly is capable of rotational movement. In the embodiments having such a rotational assembly, this assembly acts to rotate the engagement/slip assembly, and hence rotate any pipe(s) held by that assembly to facilitate attachment to other sections of pipe.
A large cylindrical opening is provided through the center of the frame for receiving a section of pipe that will extend through the opening into the mouse hole. In several embodiments, a plurality of movable support slips are provided around the inside of this opening for engaging a section of pipe inserted into the opening. The slips are capable of generally radial movement toward or away from the center of the opening. The slips move inward in order to engage a pipe section, and outward to release a pipe section. Skid plates, teeth or other rough frictional surfaces may be provided on the inwardly facing surfaces of the slips where they touch the pipe section in order to more securely engage the pipe section and prevent slippage. In several embodiments, the slips may be arcuate members, which may form a sectioned generally cylindrical clamping system. The slips need not be arcuate, however, as any suitably shaped set of slips may be provided so long as firm releasable engagement of the pipe section may be achieved. Individual slips (or pairs or groups of slips) separate from each other when moved outward in order to increase the size of the central opening to receive (or release) a pipe section. These slips come together when moved inward to decrease the size of the central opening to engage a pipe section. This allows for engagement with pipe sections having a wide variety of different diameters. In alternative embodiments, removable extensions may be provided on the slips to provide for prolonged wear of the slips by allowing for replacement of the removable extensions. In other embodiments, removable extensions may be provided for engagement with particularly narrow drill pipe sections. In such embodiments, frictional surfaces may be provided on the interior surfaces of the extensions where they come into contact with the drill pipe section.
In several embodiments, the automated movement of the slips is controlled by lever assemblies or linkages which establish the radial paths along which the slip assemblies extend and retract in relation to the center of the mouse hole. In these embodiments, the extension and retraction (inward and outward movement) of the slips is imparted by the lever assemblies. In some embodiments, a first arm is provided that extends across and is pivotally attached to the top of a generally cylindrical wall that defines the large central opening of the support frame. One end of the first arm is pivotally attached to one or more of the slips, and the opposite end is pivotally attached directly or indirectly to a motion imparting member. Thus, as the opposite end of the first arm is pulled down, the first arm acts as a lever across the generally cylindrical wall, such that the other end of the first arm (attached to the slip(s)) is raised, thereby raising the slip(s) upward and outward from the center opening. This opens the central opening for receiving (or releasing) a pipe section. The downward motion of the opposite end of the first arm is accomplished by the motion imparting member pulling downward. The farther down this member pulls the first arm, the higher and farther the slips are raised upward and outward from the center of the opening. Force may be imparted to the movable members from any appropriate source such as electrical, hydraulic, pneumatic, or mechanical provided by motors, pistons, engines or the like. In some embodiments, a second arm is pivotally connected to the opposite end of the first arm forming an elbow. In these embodiments, the opposite end of the second arm is pivotally attached to a motion imparting member that is capable of moving up and down, thereby transferring this motion through the second arm to the first arm.
It is to be appreciated that reversing this motion will cause the slips to move downward and inward toward the center of the opening. In particular, as each movable member moves up, it raises the opposite (or elbow) end of each first arm. This causes the other end of each first arm to travel downward and inward towards the center of the opening, bringing the slip(s) with it. This motion may be continued until the slips engage a pipe section in the opening, or until the slips are fully extended (preferably, but not necessarily flush with the upper surface of the frame) if no pipe is present. The movable member(s) impart sufficient force to the first arm (through the second arm, if used) to the slips to hold not only the weight of the pipe section engaged by the slips, but also the weight of other pipe sections attached thereto.
In some embodiments, the upward and downward motion is imparted through a peripheral (sometimes annular) support structure surrounding a generally cylindrical support wall, to which each of the lever assemblies is pivotally connected, either directly or indirectly. The peripheral support structure rotates with the cylindrical support wall, lever assemblies and slips in order to allow the slips to be rotated as part of the pipe coupling process. In other embodiments, these structures do not rotate. As the peripheral support structure moves downward, it causes the slips to move upward and outward. This motion is accomplished through the lever action of the arms attached to the slips which govern their movement, pulling them up and away from the center, so that the slips move both outward and upward at the same time. Then, when the peripheral support structure moves upward, the lever action of the linkages moves the slips down causing the slips to extend toward the center so that they move downward and inward at the same time. In some embodiments, the peripheral (sometime annular) support structure is rotatable with the generally cylindrical support wall. In other embodiments, the peripheral structure is not capable of such rotation.
When the slips are retracted in an outward and upward direction, a section of pipe may be lowered through the central opening and into the mouse hole. Once the pipe section has been vertically lowered to a desired position into the mouse hole, the peripheral support structure or other motion imparting device(s) are activated to compress the slips against the surface of the pipe. The force of the compression of the slips against the pipe section holds it in place. In addition, if the pipe is positioned such that its larger-diameter end portion is above the slips, the annular shoulder on the pipe also helps serve to prevent the pipe from falling though the opening and into the mouse-hole. It is to be appreciated that slips of different sizes and shapes may be attached to the linkages so long as the chosen configuration allows for capture and release of the particular drill pipe sections in use.
In several embodiments, once a section of drill pipe is engaged by the slips, the slips are capable of rotating the pipe section to secure it to either the kelley or to another section of pipe while still in the mouse hole. In these embodiments, rotational movement is imparted to the peripheral structure which rotates with the central cylinder, thereby rotating the slips and the secured drill pipe section around a central axis. In some embodiments, the peripheral structure is attached directly or indirectly (e.g., to the cylindrical wall) to, or includes a large gear structure having a set of cogs or teeth around its circumference. In these embodiments, a motor or other rotational member having a smaller corresponding and interengaging gear is provided adjacent to the large gear, such that operation of the motor or other rotational member imparts motion from the smaller gear to the larger one, thereby rotating the entire support system, including the peripheral support structure, generally cylindrical support wall, lever assemblies and slips.
In other embodiments, the peripheral support structure is not capable of rotational movement, but merely imparts the upward/downward movement necessary to extend and retract the slips. In some embodiments, the peripheral support structure is replaced by separate fixed-position lifting structures that are provided for each lever assembly or linkage. In these non-rotational embodiments, the rotational movement of the pipe section is imparted from an external source such as an iron roughneck or the like.
In those embodiments using a peripheral support structure, it is important that upward and downward motion be imparted to the support structure evenly. In several embodiments, this is accomplished by means of lifting structures that are positioned around the peripheral support structure. At least two lift points should be used, and the lift points should preferably be equally spaced from each other. This allows for uniform upward and downward movement of the peripheral support structure. If two lifts are used, they should be positioned at opposite locations around the periphery of the support structure (i.e., about 180° apart); if three lifts are used, they should be equally spaced from each other (i.e., about 120° apart); if four are used, the equal spacing should be about 90° apart; etc. The lifting structures may be electrical, hydraulic, pneumatic, or mechanical with the lifting and lowering force provided by motors, pistons, engines or the like.
In the rotating embodiments and in other embodiments, each lifting structure may be provided with a follower that may be positioned adjacent to the peripheral support structure. In these embodiments, it is preferred that the outer edge of the support structure have an annular form. The follower may be raised and lowered by the lifting structure. In some embodiments, these followers are in the form of a slightly arcuate plate that conforms to the curvature of the annular support structure. In the rotating embodiments, one or more wheels extend out from each follower above the annular support structure; and one or more additional wheels extend out from each follower below the annular support structure. As a result, in these embodiments, the wheels of each follower are deployed both above and below the annular support structure, sandwiching the support structure between them. When the lifting structure raises the follower, the wheels that are located below the annular support structure come up underneath and make contact with the lower surface of the annular support structure, transferring the upward motion to the annular support structure thereby raising it upward. Similarly, when the lifting structure lowers the follower, the wheels that are located above the annular support structure come down and make contact with the upper surface of the annular support structure, transferring the downward motion to the annular support structure thereby lowering it. The wheels on the followers are spaced sufficiently to allow the annular support structure to rotate freely with the generally cylindrical support wall, while staying sandwiched between them. All of the components of the system are made of durable preferably metal materials in order to transfer sufficient force to hold and rotate the heavy pipe sections that are placed into the invention.
In the embodiments where the peripheral support structure is not capable of rotational movement, the lift(s) may be attached directly to the support structure. In alternative embodiments, follower(s) or linkage(s) may be provided with the lift(s) to attach the lifts to the peripheral support structure to permit raising and lowering of the support structure. In alternative embodiments, guides may be provided which extend out from each follower above and below the support structure, sandwiching the support structure between them. In these alternative embodiments, the guides may be attached to the peripheral support structure but this is not necessary. When the lifting structure raises the follower in the embodiments where the support structure is sandwiched between upper and lower guides, the guides located below the support structure transfer the upward motion to the support structure thereby raising it. Similarly, when the lifting structure lowers the follower, the guides located above the peripheral support structure come down transferring the downward motion to the support structure thereby lowering it.
It is to be appreciated that in the non-rotating embodiments, the peripheral support structure may be replaced by separate coordinated lifts or lifting structures for each linkage, which raise and lower all of the linkages at the same time for even movement. In these embodiments, followers may be employed, but are not necessary.
Once a subsequent section of pipe is properly secured to first pipe section in the mouse hole, the slips can be released, and the pipe chain lowered until the top of the uppermost pipe section is positioned for engagement by the slips. Then another pipe section may be attached, and so on, until the drill pipe chain has a desired length. At that time, these attached sections of pipe can be removed as a unit from the mouse hole and attached as a unit to the existing drill pipe string.
It is therefore an object of the present invention to provide methods and apparatus for improving the efficiency of drilling operations through improved mouse hole drill pipe support systems.
It is also an object of the present invention to provide methods and apparatus for reducing the time required to set up drill pipe sections or strings prior to installation into the main drill string.
It is also an object of the present invention to provide methods and apparatus for supporting and engaging drill pipe in a mouse hole that allows for multiple drill pipe sections or joints to be attached together before being attached to an existing drill string.
It is also an object of the present invention to provide methods and apparatus for securely engaging and disengaging drill pipe sections inserted into a mouse hole without having to manually insert or remove separate support shims or slips.
It is also an object of the present invention to provide apparatus for supporting and engaging drill pipe in a mouse hole that may be mounted above, below or into the floor of a drill rig.
It is another object of the present invention to provide portable apparatus for supporting and engaging drill pipe in a mouse hole that may be retrofitted onto an existing drill rig floor.
Additional objects of the invention will be apparent from the detailed descriptions and the claims herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective view of an embodiment of the apparatus of the present invention in a closed position.
FIG. 2 is a top plan view of the embodiment of FIG. 1 .
FIG. 3 is a side elevational view of the embodiment of FIG. 1 .
FIG. 4 is a side cross-sectional view along line A-A of FIG. 3 .
FIG. 5 is a perspective view of the embodiment of FIG. 1 with the support frame removed to show detail.
FIG. 5A is a partially cut-away perspective view of the embodiment of FIG. 5 .
FIG. 5B is a detail view of a portion of the embodiment of FIG. 5A .
FIG. 6 is a side perspective view of an embodiment of the apparatus of the present invention in an open position.
FIG. 7 is a top plan view of the embodiment of FIG. 6 .
FIG. 8 is a side elevational view of the embodiment of FIG. 6 .
FIG. 9 is a side cross-sectional view along line B-B of FIG. 8 .
FIG. 10 is a perspective view of the embodiment of FIG. 6 with the support frame removed to show detail.
FIG. 10A is a partially cut-away perspective view of the embodiment of FIG. 10 .
FIG. 10B is a detail view of a portion of the embodiment of FIG. 10A .
FIG. 11 is a rear perspective detail view of an embodiment of a lift and follower of the present invention.
FIG. 12 is a front perspective detail view of an embodiment of a follower of the present invention.
FIG. 13 is a side perspective detail view of an embodiment of a follower of the present invention.
FIG. 14 is a side perspective view of an alternate embodiment of the apparatus of the present invention in a closed position.
FIG. 15 is a side elevational view of the embodiment of FIG. 14 .
FIG. 16 is a side cross-sectional view along line A-A of FIG. 15 .
FIG. 17 is a top plan view of the embodiment of FIG. 14 .
FIG. 18 is a detailed perspective view of the embodiment of FIG. 14 in a partially opened position.
FIG. 19 is a detailed perspective view of the embodiment of FIG. 18 with the frame removed.
FIG. 20 is a cross-sectional view of a portion of FIG. 19 .
FIG. 21 is a detailed perspective view of the embodiment of FIG. 14 in a closed position with the frame removed.
FIG. 22 is a cross-sectional view of a portion of FIG. 21 .
DETAILED DESCRIPTION
Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to the illustrated embodiments of FIGS. 1-10 , it is seen that the illustrated embodiment of the present invention includes a frame 21 having an upper surface 23 and a lower surface 25 separated by a plurality of supports 27 . Frame 21 is designed for placement above a mouse hole of a drilling rig. The depth of the mouse hole should be sufficient to accommodate the desired number of pipe sections to be attached together as a unit prior to installation in the main pipe string of the drilling rig. Frame 21 may be installed such that the lower surface 25 rests upon the existing floor of a drill rig, or upon the floor surrounding the mouse hole. Alternatively, frame 21 may be installed such that upper surface 23 is flush with or below the floor of the drill rig or mouse hole. In several embodiments, frame 21 and the components provided therein (described more fully below) are portable and may be removed and transported as a unit.
At least one central opening is provided in upper surface 23 . In rotatable embodiments, such as those illustrated in FIGS. 1-2 , one or more plates 33 may be provided inside a larger opening 31 defining central opening 35 therein. In these rotatable embodiments, plates 33 preferably have an arcuate shape generally forming a circle so that plates 33 may rotate within opening 31 . In some non-rotatable embodiments, plates 33 need not rotate, so they may be of any suitable shape so as to define a central opening 35 . In some embodiments, larger opening 31 and plates 23 and/or 33 may be eliminated entirely as shown in FIGS. 14-22 .
A generally cylindrical support wall 39 defining a hollow interior is provided inside frame 21 around opening 35 . A plurality of slips 41 are deployed in the hollow interior area of wall 39 , leaving another smaller opening 37 in the center for receiving a section of pipe. The tops of slips 41 may have a shape that conforms to the shape of opening 35 . In alternative embodiments, slips 41 may be of any shape that fits inside opening 35 and cylindrical wall 39 while still providing a central opening 37 for receiving a pipe section. The number and spacing of slips 41 should be established so that they may engage and hold a section of pipe. The inwardly facing surfaces of slips 41 may be provided with frictional surfaces 43 such as skid plates or teeth, which come into direct contact with a drill pipe section when the slips are engaged (closed) around the pipe to hold it firmly in place. In alternative embodiments, removable extensions 42 may be provided on slips 41 that can more easily be removed and replaced when worn and at a lower cost than replacing the slips 41 themselves. In such embodiments, frictional surfaces 43 are provided on the interior surfaces of extensions 42 where they come into contact the drill pipe section.
It is to be appreciated that neither the support wall 39 nor the hollow interior thereof need be of uniform diameter over the length of their longitudinal axes, or that the hollow interior area itself be generally cylindrical. In some embodiments, the diameter of the support wall 39 will be greater in the area in which the slips are positioned than in other areas. It is also to be appreciated that the exterior of support wall 39 may be generally cylindrical as shown in the illustrated embodiments, but that any other suitable shape (square, rectangular, hexagonal, etc.) may alternatively be used.
A plurality of lever assemblies or linkages are provided in conjunction with slips 41 . In several embodiments, these assemblies include upper arms 51 that act as levers. One end of each upper arm 51 is pivotally attached to one or more slips 41 at pivot 56 . The opposite end of each arm 51 is attached directly or indirectly to an upward/downward motion imparting member. In the illustrated embodiment shown in FIGS. 9 and 10B , it is seen that the opposite end of arm 51 is pivotally attached at 52 to a second arm 53 , and second arm 53 is linked at pivot 58 to a movable structure 63 . In the illustrated exemplary embodiment, structure 63 is an annular ring that encircles support wall 39 ; however, it is to be appreciated that in other embodiments structure 63 may be provided in any shape extending around the periphery of wall 39 . Each upper arm 51 extends across and is pivotally attached to the top of support wall 39 at 54 forming a lever, with this pivotal attachment 54 at wall 39 acting as the fulcrum. In alternative embodiments, lower arm 53 may be eliminated, and one end of upper arm 51 may be attached directly to an upward/downward motion imparting member such as structure 63 . This direct attachment may or may not be pivotal, depending on the type of motion imparting structure used. Structure 63 , is moved up and down, either directly or indirectly, by a lift 71 or other device as described more fully below.
Comparing FIG. 5B with FIG. 10B , it is seen that as each upper arm 51 is pulled down at pivot 52 (either directly or through lower arm 53 or the like), arm 51 acts as a lever across pivot attachment 54 , such that the opposite end of upper arm 51 at pivot point 56 is raised, thereby raising the slip(s) 41 upward and outward from the central opening 37 . This opens the hollow interior of wall 39 for receiving (or releasing) a pipe section as shown in FIGS. 8-10 . As the motion imparting device(s) move downward, it forces slips 41 to move upward and outward. As this occurs, the lever assemblies govern the movement of slips 41 , pulling them up and away from the center, so that slips 41 move both outward and upward simultaneously. An example of this open position is illustrated in FIGS. 6-10 . The farther down the motion imparting member(s) pull upper arms 51 at pivot 52 , the higher and farther the opposite ends of upper arms 51 at pivot point 56 and slips 41 are raised upward and outward from the central opening 37 . The devices 71 that impart motion to structures such as 63 may be of any suitable form including without limitation electrical, hydraulic, pneumatic, or mechanical, such as motors, pistons, engines or the like.
It is to be appreciated that upward motion from the motion imparting devices at pivots 52 of arms 51 will cause the slips 41 to move downward and inward toward the center of opening 37 . In particular, as each motion imparting device moves up, it raises end 52 of upper arm 51 , either directly or through lower arm 53 or the like. This causes the other end 56 of the upper arm 51 to travel downward and inward towards the center of the opening 37 , bringing the attached slip(s) 41 with it. This motion is used to engage the slips 41 against a pipe section in opening 37 , or to bring the slips to a closed position if no pipe is present as shown in the exemplary embodiment of FIGS. 1-5 . The motion imparting device(s) impart sufficient force through the lever assemblies to the slips 41 to hold not only the weight of the pipe section engaged by the slips, but also the weight of other pipe sections that may be attached thereto.
It is to be appreciated that upward/downward motion imparting member(s) may be provided in numerous alternative embodiments. In the illustrated embodiments of FIGS. 1-10 , a single structure 63 is provided to which each of the lever assemblies is attached. Structure 63 in the form of a peripheral support member that conforms to the outer surface of wall 39 . As structure 63 moves downward, it forces the slips 41 to move upward and outward. As this occurs, the arms 51 (and/or linkages 53 ) attached to the slips govern their movement, pulling them up and away from the center, so that the slips 41 move both outward and upward at the same time. This open position is illustrated in FIGS. 6-10 . Then, when structure 63 moves upward, the lever action of the assemblies moves the slips 41 down causing the slips to extend toward the center so that they move downward and inward at the same time. This closed position is illustrated in FIGS. 1-5 .
It is to be appreciated that in some embodiments, separate up/down motion imparting members may be provided for each lever assembly (as shown in FIGS. 14-17 ), or that different groups of lever assemblies may be operated by different motion imparting members. It is to be appreciated that different combinations of motion imparting devices and lever assemblies may also be used, and different linkages or combinations of linkages may be employed between devices 71 and lever arms 51 . When multiple motion imparting devices are used, the motion of the lever assemblies should be coordinated in order to impart consistent motion to each linkage, in order to raise and lower the slips 41 in a uniform manner.
In the non-rotating embodiments, it is not necessary for slips 41 to rotate around opening 37 to rotate an engaged pipe section. Thus, the upward/downward motion may be imparted directly to each lever assemblies using its own lift 71 that may be more directly connected to the lever assembly, eliminating member 63 . An example of such lifting assemblies is shown in FIGS. 14-17 .
However, in the rotatable embodiments, such as that shown in FIGS. 1-10 , it is generally desirable to separate the upward/downward motion imparting members from the remaining rotatable parts of the invention so that the slips (and the structures associated with them—levers, cylindrical wall, etc.) may rotate freely and independently of the upward/downward motion imparting members. An example of how this separation is accomplished is illustrated in the embodiments of FIGS. 1-13 . In these illustrated embodiments, it is seen that upward and downward movement is imparted to the lever assemblies and structure 63 by a plurality of lifts 71 . Each lift 71 engages structure 63 in a way that allows structure 63 to rotate along with wall 39 , the lever assemblies, and slips 41 independent of the lifts 71 themselves. As shown in FIGS. 10 and 13 , each lift 71 is provided with a follower 73 that is positioned immediately adjacent to structure 63 . Followers 73 are raised and lowered by lifts 71 . As exemplified in FIGS. 11-13 , followers 73 are in the form of angled or slightly arcuate plate(s) that conform to the curvature of the annular support structure 63 . One or more rotatable members 75 extend out from each follower 73 below the annular support structure; and one or more additional rotatable members 77 extend out from each follower 73 above the annular support structure. As a result, the rotatable members of each follower are deployed both above 77 and below 75 the annular support structure 63 , sandwiching the support structure between them. Members 75 and 77 are rotatable in order to minimize friction while in contact with annular support structure 63 when it is rotated along with wall 39 , the lever assemblies and the slips. It is to be appreciated that the followers may be provided in different forms so as to impart raising and lowering movement to annular support structure 63 . For example and without limitation, followers may be in the form of posts, brackets, webbing or the like; and members 75 and 77 may be provided in the form of plates, bearings or even gears with teeth that intermesh with corresponding teeth on structure 63 . In other embodiments, a single hydraulic or pneumatic source may operate a plurality of lifts, each lift being connected to a follower adjacent to the annular support structure 63 .
In the exemplary illustrated embodiments of FIGS. 1-13 , when a lift or lifting structure 71 raises a follower 73 , the rotatable members 75 that are located below the annular support structure 63 come up underneath and make contact with the lower surface of the annular support structure 63 , transferring the upward motion to the annular support structure thereby raising it upward (and closing the slips 41 ), as shown in FIGS. 1-5 . Similarly, when the lifts or lifting structures 71 lower the followers 73 , the rotatable members 77 that are located above the annular support structure 63 come down and make contact with the upper surface of the annular support structure, transferring the downward motion to the annular support structure thereby lowering it (and raising the slips 41 ), as shown in FIGS. 6-10 . The rotatable members 75 , 77 on the followers 73 are spaced sufficiently to allow the annular support structure 63 to rotate freely with wall 39 , while staying sandwiched between them.
Upward and downward motion must be imparted to annular support structure 63 in a way that allows this structure to stay relatively level. This is important in order to cause uniform movement of the slips 41 resulting in firm, even engagement of a pipe section. In several embodiments, this is accomplished by means of one or more motion imparting devices or lifts 71 that are positioned around the annular support structure 63 . It is preferred that the annular support structure 63 be lifted from at least two different locations in order to keep structure 63 in a relatively level position as it is raised and lowered. This may be accomplished using a single lifting mechanism that operates two or more lifting structures to lift annular support structure 63 . In some embodiments, two lifting structures 71 may be used; in others, three such structures may be used. In the illustrated embodiments, four lifting structures 71 are shown, although any suitable number of lifting structures or lifting locations may be used. It is preferred that the lifting structures or locations be positioned relatively equidistant from each other around the support structure 63 to keep it relatively level. Motion imparting device(s) or lifts 71 may be of any suitable form including without limitation electrical, hydraulic, pneumatic, or mechanical, such as motors, pistons, engines or the like.
In the non-rotatable exemplary embodiment of FIGS. 14-22 , support structure 63 has been eliminated; however, it is to be appreciated that in other non-rotational embodiments, a peripheral support structure such as structure 63 may be used to assure uniform movement of the lever assemblies and slips. In rotational embodiments, support structure 63 is capable of rotating in conjunction with wall 39 in order to allow the slips and linkages to be rotated as part of the pipe coupling process.
In other embodiments, support structure 63 is eliminated and motion imparting device(s) 71 are attached or linked more directly to the lever assemblies. Like support structure 63 , the motion imparting device(s) will cause the slips 41 to move downward and inward toward the center of opening 37 . In particular, as each motion imparting device moves up, it raises upper arm 51 at pivot 52 with or without a lower arm 53 . This causes upper arm 51 at pivot point 56 to travel downward and inward towards the center of the central opening 37 , bringing slip(s) 41 with it. This motion is used to engage the slips 41 against a pipe section in the opening, or to bring the slips to a closed position if no pipe is present. The motion imparting device(s) 71 impart sufficient force to slips 41 to hold not only the weight of the pipe section engaged by slips 41 , but also the weight of other pipe sections attached thereto. It is to be appreciated that in rotatable embodiments of the invention, motion imparting devices 71 may be separated from the lever assemblies to allow rotation, while still providing the desired upward/downward motion.
In alternative embodiments, a separate motion imparting device 71 may be provided with each lever assembly, and/or with pairs of linkage assemblies, and/or in other combinations. The movement of these motion imparting devices 71 should be coordinated in order to impart consistent motion to all lever assemblies, in order to raise and lower the slips 41 in a uniform manner.
In other embodiments, lifts 71 are pivotally connected directly or indirectly to the lever assemblies or linkages, whichever is the case, so structure 63 and separate followers 73 are not required.
The rotatable embodiments of FIGS. 1-10 illustrate embodiments of the invention where the engagement/slip assembly rotates a first engaged drill pipe section to be joined with a second drill pipe section which is in a fixed position. In the rotational embodiments, rotational movement is imparted to the support structure 63 which rotates in conjunction with the support wall 39 , thereby rotating slips 41 and the engaged drill pipe section around the axis defined by the central opening 37 and wall 39 . In some of these rotatable embodiments, wall 39 and support structure 63 are attached directly or indirectly to a rotating mechanism, such as a gear. In the illustrated exemplary embodiment, a large gear structure 65 is attached to or incorporated into wall 39 having a set of cogs or teeth 66 around its circumference. In these embodiments, a motor or other rotational member 67 having a smaller corresponding and interengaging gear 68 is provided adjacent to the large gear 65 , such that operation of the motor or other rotational member imparts motion from the smaller gear to the larger one, thereby rotating support wall 39 , annular support structure 63 and everything attached to it, including the slips 41 and lever assemblies 51 and/or 53 . While a gear has been illustrated as a means of imparting rotation, other means may also be employed such as a belt system, chain driven sprockets, direct drive motor(s), or the like.
In use, the slips 41 are retracted to an outward and upward position, opening the central opening 37 so that a section of pipe may be lowered through the central opening and into the mouse hole below. Once the pipe section has been lowered to a desired position into the mouse hole, the annular support structure or other motion imparting device(s) or lifts are activated to compress the slips 41 and/or the frictional surfaces 43 against the surface of the pipe. The force of the compression of the slips against the pipe section holds it in place. Because of the generally radial inward-outward motion of the slips, generally any pipe section having a diameter that is smaller than the opening 37 provided by the retracted slips may be engaged. Slips of different sizes or shapes may be used to change the size and/or shape of this opening at setup, and/or extensions 42 may be attached to the slips. However, once the slips (with or without extensions) have been installed, it is generally not necessary to insert, remove or change them out during operations.
Once the first section of pipe has been grasped by the slips, another section of pipe is then positioned adjacent to the pipe being held by the slips. In the stationary embodiments of the invention, the slips hold the pipe section in a fixed position, and rotational movement is supplied from an external source to join the pipe sections together. In the rotational embodiments of the invention, the rotational movement is imparted to the support wall 39 and/or support structure 63 which rotates the linkages and slips. This causes the held section(s) of pipe to rotate relative to the new section, causing them to be joined together. The slips are then retracted by downward movement of the annular support structure or other motion imparting device(s) or lifts, allowing the pipe section to be removed, or lowered further into the mouse hole and engaged again. The process may then be repeated for subsequent pipe sections. When enough pipe sections are connected together in the mouse hole, the string of sections is removed and attached as a group to the main string of the drill rig.
It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof, and that different combinations of the various features identified herein are contemplated within the scope of the invention. It is also to be understood that the present invention is not to be limited by the particular embodiments described or illustrated herein, but only in accordance with the appended claims when read in light of the foregoing specification. | The present invention allows for the connection of multiple sections of drill pipe in a mouse hole by securing a given section of pipe in the hole and delivering a rotational force to secure that pipe section to another section of drill pipe placed above it over the mouse hole. In some embodiments, the rotational force may be provided by the support unit of the present invention. In alternative embodiments, the rotational force may be provided by an outside source such as an iron roughneck, with the support unit of the present invention holding the drill pipe section in a stationary position as such force is delivered. The unit then allows the connected pipe sections to be lowered and secured so the process can be repeated to connect multiple sections of drill pipe together in the mouse hole. The multiple sections of drill pipe may then be retrieved as a unit, and attached to the pipe string already being used to drill the well. | 4 |
REFERENCE TO RELATED APPLICATIONS
This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/780,157 filed Mar. 13, 2013.
TECHNICAL FIELD
The present invention relates to the field of cleaning aqueous waste streams, and more specifically, provides a processing unit for aqueous waste streams which improves the flocculation and separation of contaminants by increasing the amount and size of the floc, which provides for much improved separation and removal of contaminants from the aqueous waste stream.
BACKGROUND
The present invention is a processing unit for the electrolytic treatment of aqueous waste streams employing the effects of three technologies; electromagnetics, oxidation and electrolytics (EMOERU) taking place in the proper order in a single processing unit fabricated of materials which are chemically inert. The inventive processing unit treats aqueous solutions in the correct order specific to the contaminant to be removed, and if required for specific contaminants, an additional filter utilizing nanotechnology can be attached to the processing unit to further filter the aqueous stream as it exits the unit.
Electro-(coagulation, precipitation or flocculation) entered into commercial application with Cottrell's smoke stack dust precipitator in the late 1800's. One of the best representations of the art as applied to fluids is the Liggett patent, U.S. Pat. No. 4,293,400. All others are some variation of the basic concept. Some of the best documentation of the results of Electroflocculation was presented in U.S. Pat. No. 4,872,959 titled “Electrolytic Treatment of Liquids” as presented by Robert J. Herbst and Russell R. Renk with their patent of the “tube within a tube” configuration. However the time consuming maintenance required by this configuration, cost of special parts fabrication, difficulty locating close tolerance tubing and maintaining proper clearance between the inner and outer tubes necessitated that a better solution be found. In U.S. Pat. Nos. 4,293,400, 4,378,276 and 4,872,959 there are described devices for applying an electric field to a liquid flowing through the devices. These devices employ the tube within a tube configuration. In U.S. Pat. No. 5,043,050, which is by Robert J. Herbst, all of the many noted problems of cost, material acquisition and difficulties of maintenance of the tube within a tube device are quite well covered.
There have been many methods put forward for the removal of contaminants from aqueous waste streams. There exist many forms and shapes of electrocoagulators. Most electrocoagulation (Electroflocculation) units are quite difficult to maintain and clean out. This must be accomplished on a regular basis if the units are to perform correctly. As a solution to this, some have advocated using chemicals while others have added a fluidized bed of conductive particles to aid in eliminating this problem. This usually just introduces a new problem.
U.S. Pat. Nos. 4,053,378, 4,094,755 and 4,329,111 describe using flat plates and fluidized beds. The flat plate device patents discuss the need for caution due to maintenance problems encountered caused by buildup of solids from the waste stream on the carbon granules used in the fluidized bed. All of these devices are single technology treatment units.
The present invention not only helps to solve the flow problems present in the prior art but also greatly increases the overall contaminant removal rate. The electromagnetic ionic realignment improves flocculation and reduces scaling depositions on the charged treatment plates. The microscopically bubbled ozone aids in the turbulence and the rapid formation of hydroxyl radicals as a result of oxidation, which accelerates flocculation and chemical reduction of the contaminants. Polarity, anode and cathode, reversal reduces plating action on the charged treatment plates. The physical design of the inventive processing unit is such that visual inspection, maintenance and occasional plate replacement is quite easy and rapid.
SUMMARY OF THE INVENTION
The invention has been designed with the following principal advantages: improvement of processing, reduction of fouling, facilitation of visual inspection and simplification of maintenance by the utilization of the synergistic effects of the technologies of electromagnetics, oxidation and electrolysis, (EMOERU), while allowing more flexibility in processing different types of aqueous waste streams by employing multiple types of interchangeable treatment plates depending on the type of aqueous waste stream being processed. The physical design of the flow through horizontal maze processing unit is such that maintenance and occasional plate replacement is quite easy and rapid. The maze is designed to take full advantage of physical laws and physicochemical reactions by utilizing a series of horizontal maze flow channels constructed with a vertical descent to each succeeding flow channel to fully utilize the effect of the fluid flow against the natural rise of the extremely fine Venturi injected Ozone/Oxygen bubbles as required for a particular contaminant.
By utilizing a strong electromagnetic field along with saturating the fluid stream with microscopic ozone/oxygen bubbles, (the (EMO) section of (EMOERU)), combined with automatic and systematic polarity reversal of the treatment plates, it has been possible to dramatically reduce the major buildup problems. In addition, the ozone bubbles are in constant agitation of the fluid stream exposing more of the fluids to the treatment plates. The ozone also enhances the formation of the hydroxyl radicals and hydroperoxides, which accelerate and aid in the formation of floc and oxidation of almost all contaminants. All of this is accomplished by the synergistic interactions and reactions of the three technologies being applied simultaneously within the processing unit.
Reaction rates are influenced differently by AC or DC treatment depending on the type of contaminants present. It is important to supply an adequate power source to meet the demands of the waste stream. What will control the required current and voltage supplied to these plates is as follows: Voltage will have to be set at a sufficient level to drive the required current through the fluid stream. This is a function of the distance between the treatment plates. The current demand is the amount of Amps required to properly remove all contaminants from the fluid stream. This is a function of the conductivity of the contaminated stream itself, which is in turn the function of conductivity of the combination of types of contaminants (suspended and dissolved solids in the waste stream) and the quantity of the contaminants (concentrations). This will indicate the electron charge requirements to either change state or cause flocculation and sedimentation of the dissolved and suspended solids, which make up the contaminants of a particular fluid stream. In most cases the fluid stream will, due to its conductivity, draw the current required for proper processing.
The removal of contaminants is quite often directly affected or controlled by the pH of the stream. Before the contaminated stream is sent to the processing unit the pH, if need be, can be adjusted as required for the best removal by any of the commonly known methods of pH adjustment.
Actual physical dimensions of the processing unit will be dependent on the desired treatment flow as well as the number of treatment plates used in the unit. The plate thickness, width and length as well as space between plates, may be varied to meet specific removal requirements. The processing unit is designed with horizontal flow maze channels with a vertical descent between each succeeding maze flow channel, thus taking full physical advantage of the downward fluid flow against the natural rise of the Venturi-injected minute ozone bubbles to attain maximum ozone contact time within the unit. When used for a specific and constant waste stream, the unit can be specifically designed to be more efficient at removal of very specifically targeted contaminants.
The processing unit itself is constructed of non-conductive material that is resistant to acids, caustics, organic and inorganic chemicals and contaminants, solvents, chlorinated hydrocarbons and oxidation by ozone. The sidewalls are grooved, while the ends of the treatment plates engage the grooves and a highly conductive metal contact to hold the treatment plates in place. Every other channel and plate will nest in one end and stop short of other end, while the alternate plate and channel will nest in the other end and stop short of the other end to create the horizontal maze flow in the unit.
The aqueous waste stream is introduced into the top of the processing unit through an inlet conduit which communicates with the interior of the processing unit and allows flow through of the aqueous waste stream to a horizontal maze of treatment plates. A number of flow channels exist in the horizontal maze and flow proceeds from channel to channel falling vertically to the outflow point on bottom where an output conduit has been attached to receive the outflow. Attached to the output conduit is a U-shaped pipe which extends from tank side and rises to the top of the treatment area top level and in an inverted configuration, descends to connect just beyond where the bottom drain cut-off valve is attached. This allows the free flow output after the treatment unit is full and as long as fluid continues to enter the unit, when input fluid flow stops then the drain cut-off valve opens to allow the treatment unit to drain completely through the treatment outflow point.
On the end of the entry pipe a venturi injector is mounted to the unit entry to inject ozone/oxygen directly into the fluid flow as it enters into the process unit. Connected directly to the venturi injector, so as to accomplish ionic alignment before blending the ozone is an electromagnet sized to system flow. An electromagnet is utilized as it has proven to be more effective at ionic alignment than a permanent type magnet. Liquid flow pressure is monitored by pressure gauges.
The treatment plate maze arrangement is as follows: An aqueous waste stream enters the processing unit at its top. The maze is so arranged that the flow is lengthwise of the unit. Flowing from one end to the other end around the end of each treatment plate and downward into the next horizontal maze flow channel. This continues in a downward manner until the last flow channel is reached. The waste stream then exits out of an output pipe. The various flow channels are bordered by plates of opposite polarity, one plate being an anode and the other a cathode. In the center of each flow channel frames containing membranes can be installed as may be required for treatment of specific waste streams. These may be “doped” (chemically impregnated or other type of treatment but not limited to nanofiltration, nanoparticles or enhanced nanomagnetic particles) screens or other forms.
The method of plate installation allows the use of many types of anode and cathode plates. It is possible to use multiple treatment plate configurations to meet the removal parameters of the contaminants being treated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exterior side view of the inventive processing unit comprising the invention.
FIG. 2 is a perspective view of the inventive processing unit comprising the invention shown with its access lid removed so as to provide a full view of the maze unit.
FIG. 3 is a plan view of the inventive processing unit, shown with the access lid removed and looking downward at the various plates comprising the maze unit.
FIG. 4 is a perspective view of an electrical contact which is part of the invention.
FIG. 5 is an exterior side view of the inventive processing unit.
FIG. 6 is a plan view of an anode plate, a cathode plate and a membrane attached between the anode and cathode plates attached to various wiring and ammeter shunts which comprise the invention.
DETAILED DESCRIPTION OF THE INVENTION
This is a flow through processing unit apparatus, which consists of the following technologies: electromagnetics, oxidation and electrolytics, (EMOERU), arranged in such a manner to take full advantage of the synergistic physicochemical actions and reactions when these technologies are applied simultaneously in a confined environment in a specially designed processing unit.
Referring generally, to FIG. 1 , the processing unit 10 is comprised of a rectangular housing 12 made of non-conductive material resistant to acids, caustics, organic and inorganic chemicals and contaminants, solvents, chlorinated hydrocarbons and ozone oxidation. The housing 12 is preferably capable of handling pressures of at least 60 psi and the exact dimensions of the housing is dependent upon the use to which it is applied. The housing dimensions can be modified for a specific non-variable contaminant and gpm flow rate at a permanent site without being at variance to this patent. Other internal dimensions and exact number of plates for a particular application may vary. As shown in FIGS. 2 and 3 the housing 12 has sidewalls 14 , 16 which are grooved on their inner face where half of the grooves 24 contain treatment plates 68 which run from the inner face of a first sidewall 14 to within about a half-inch of and opposite, second sidewall 16 .
The other half of the grooves 25 will contain plates 69 which run from the inner face 22 of the second sidewall 16 to within about a half inch of the first sidewall 14 . These grooves 24 , 25 are staggered so that when treatment plates 68 , 69 are inserted into the grooves 24 , 25 a horizontal maze unit 28 is formed.
In FIGS. 2 and 3 the housing 12 with associated plates 68 , 69 is shown with its access lid (not shown) removed so that the plates can be seen in their horizontal orientation to form a horizontal maze unit 28 . The horizontal maze unit 28 shown in FIG. 2 also shows aqueous waste stream effluent (effluent stream flow indicated by arrows) entering at the inlet 29 at the top side 31 of the housing 12 , cycling across the various plates 68 , 69 via gravity feed until the effluent reaches the outlet 30 located at the bottom side 27 of the housing 12 .
Inlet 29 communicates with an input conduit 32 as shown in FIG. 1 . Along the input conduit 32 , processing apparatus can be included to act upon the aqueous waste stream prior to its entry into the maze unit 28 as shown in FIG. 1 . One such apparatus is an electromagnet 34 as shown in FIG. 1 . Another is a venturi injector 36 as shown in FIG. 1 to which oxidizing agents can be added to act upon the waste effluent stream. One such oxidizing agent would be ozone 33 as shown in FIG. 1 , which would be introduced at the venturi injector 36 as shown in FIG. 1 . Just after the venturi injector 36 is inlet 29 to the processing unit 10 , through which an effluent waste stream is introduced to the horizontal maze unit 28 of treatment plates 68 , 69 as shown in FIG. 2 .
Still referring to the FIGS. 1 and 2 the processing unit has an outlet 30 with a drain valve 40 on the bottom. An output conduit 46 extends from outlet 30 , which in turn connects to an inverted pipe configuration 44 . The inverted pipe configuration 44 keeps water filled to the top of the water level in the housing 12 to prevent the processing unit 10 from shorting out. Drain valve 40 is located on output conduit 46 . At the bottom 27 , there is an outflow arrangement. This will consist of a flat offset spacer block 48 that the output conduit 46 is attached to. The output conduit 46 is sized to the unit's maximum flow rate. The output conduit 46 extends to connect to a “T” junction 52 which is connected to riser 54 off of the top of the “T” junction 52 which rises to the top fluid level 56 of a full treatment unit. Pipe configuration 44 also allows an extension 58 for the installation of other equipment if necessary for further reduction of contaminants beyond acceptable levels. For example, as shown in FIG. 1 the free flow output can then connect to a filtration system 62 including but not limited to nanoparticles, enhanced nanomagnetic particles, biologically activated granulated charcoal, etc. Flow will be outward from the outlet 30 from the last horizontal flow channel 78 of the unit as shown in FIG. 2 .
Referring to FIGS. 2 and 3 the staggered arrangement of the treatment plates 68 , 69 which comprise the horizontal maze unit 28 is shown. Between each pair of treatment plates 68 , 69 is a channel 64 through which flows the effluent waste stream (arrows). Each channel 64 is bordered by two treatment plates 68 , 69 , one plate being an anode 68 and the other a cathode 69 . The sidewalls 14 , 16 of the housing 12 as shown on FIG. 1 have a slot (not shown) for the highly conductive metal contacts 71 as shown on FIG. 4 hold the anode or cathode treatment plates 68 , 69 in place. A plate 68 nests in a first sidewall groove 24 at the plate's first end 74 and stops short of an opposing second sidewall 16 at the second end 76 of the plate 68 , while the first end 74 of an alternate plate 69 nests in a groove 25 in the opposing second sidewall 16 and where the second end 76 of the alternate plate 69 stops short of the first sidewall 14 . This alternating plate arrangement combines in a plurality of alternating plates 68 , 69 to create the horizontal maze unit 28 . The waste stream effluent travels through the flow channels 64 and flows in a vertical manner through each flow channel from inlet 29 to outlet 30 . The plates are preferably at least ½-inch shorter than the distance between sidewalls 14 , 16 plus an allowance for insertion of contacts 71 . The material of the plates will and can be selected to meet the parameters of the waste stream. They can be mixed or matched. The plate's exact dimensions and number of plates will be dependent on the flow rate and the process time required. The aqueous waste stream, upon reaching the final channel 78 will leave the unit by the outlet 30 and the output conduit 46 as shown on FIG. 1 . The number of treatment plates and therefore, the number of flow channels in the maze unit can be modified depending on the type of aqueous waste stream being treated. For example, a particular contaminant may require the waste stream to remain in the maze using for a certain time “x” before it is adequately treated. This time “x” is called the residence time. The number of plates and flow channels can be increased or decreased to achieve the appropriate residence time for a particular waste stream.
Referring to FIG. 3 the grooves 24 , 25 imparted into the interior sidewalls 14 , 16 of the housing 12 for mounting the treatment plates 68 , 69 are shown. Grooves 24 are cut into the inner face 21 of a first sidewall 14 and grooves 25 are cut into the inner face 22 of a second sidewall 16 . A first subset of anode plates 68 are inserted into the first sidewall grooves 24 and a second subset of cathode plates 69 are inserted into the second sidewall grooves 25 . When the entire plurality of treatment plates 68 , 69 are inserted into their respective first and second sidewall grooves, the plates 68 , 69 comprise the maze unit 28 as shown on FIG. 2 and are positioned in a staggered relation. Both sidewalls 14 , 16 are provided with two holes (not shown) at each groove 24 , 25 for the mounting and securing of the contacts 71 as shown on FIG. 4 which are then connected to an power source 92 as shown on FIG. 6 to turn a plate into an anode plate 68 or a cathode plate 69 .
Referring to FIG. 4 , the contact 71 is shown. Contact 71 has a slot 108 into which is inserted a treatment plate 68 , 69 and contacts 71 are inserted into slots (not shown) located in sidewalls 14 , 16 . Stud bolts 110 extend protrudingly outward from contact 71 and extend through sidewalls 14 , 16 . As demonstrated in FIG. 5 , stud bolts 110 are protruding through sidewall 14 . The ends 74 of cathode plates 68 reside in grooves 24 and in slot 108 of contact 71 . Cables 72 as shown in FIG. 5 are attached to stud bolts 110 and to power source 92 (See FIG. 6 ).
As shown in FIGS. 5 and 6 the protruding portion of the stud bolts 110 on the outside of the side walls 14 , 16 will be the power connection points. At the positive sidewall 14 ammeter shunts 112 will connect to the stud bolts 110 and then the other end of the ammeter shunt 112 will connect to a power bus 106 . At the negative sidewall 16 the stud bolt 110 will connect directly to the other power bus 106 . The end of an anode plate 69 has all connections for one polarity while the other end has the cathode plate 68 connections. The shunts 112 are then connected to display ammeters 114 on the control panel 117 adjacent to the power unit's voltage 115 and current 116 controls. As there are two stud bolts 110 , one to each side, and due to close proximity of the plates, the shunts are connected alternately to one stud or the other to avoid close proximity problems with the shunt mounting. These shunts provide the ability to monitor the amperage drawn by each set of plates to determine efficiency of the process and will also indicate the status and condition of each set of plates.
The sidewall grooves 24 , 25 as shown on FIG. 3 are cut to a sufficient depth to hold the cathode and anode plates in place with approximately ⅜ inch spacing between plates. The sidewalls 14 , 16 are of non-conductive material. Also, while FIGS. 2 and 3 show a side removed so that access to the plates 68 , 69 can be gained, the housing 12 is entirely closed during operation and an access lid (not shown) is placed over the plates 68 , 69 and held in a fluid tight manner with a gasket and bolts. As shown in FIGS. 2 and 3 the plates 68 , 69 are removable once the cover is removed, thus allowing them to be serviced and inspected if necessary.
As shown in FIG. 6 , the processing unit 10 preferably allows for the insertion of membranes 94 between the anode and cathode plates 68 , 69 of each flow channel 64 in the horizontal maze unit 28 . The membranes can be comprised of different materials as may be required for treatment of specific waste streams. These may be “doped” membranes 94 (chemically impregnated or other type of treatment but not limited to nanofiltration, nanoparticles or enhanced nanomagnetic particles or other forms).
There are pressure gauges or sensors 102 as shown on FIG. 1 on the unit. One will be on the input conduit 32 and the other on output conduit 46 . This will indicate the pressure drop across the maze unit 28 and thus will be indicative of the unit flow status.
A volume control 103 allows the volume of influent aqueous waste stream to be regulated so as not to overwhelm the processing unit 10 .
The voltage 115 and current 116 controls of either the AC or DC power to the plates allows the operator to set and/or adjust these two parameters to meet the demands to treat a particular contaminant or group of contaminants. In the DC mode of operation there will be a time adjustable relay to reverse plate polarity as best fits contamination process.
While it has been attempted to illustrate a preferred embodiment of the inventive concept incorporating electromagnetics, oxidation and electrolytics in a specifically designed synergistic physicochemical reaction flow through unit, (EMOERU), to take full advantage of their synergistic physicochemical interactions and reactions when they are applied simultaneously within a confined processing unit, it is wished to be limited not by the specific embodiments illustrated but only by the scope of the appended claims. | An improved method and apparatus for the removal of both suspended and dissolved contaminants be they heavy metals, organics, inorganics, hydrocarbons and others from various types of waste stream, wash water, ground water, leach waters, process waters and etc. is illustrated. The method combines passing the aqueous waste stream through an electromagnetic field, an ozone/oxygen venturi injector for oxidation and then through a horizontal flow and vertical fall with a horizontal plate maze unit of alternately electrically charged plates, anode and cathode. The plates will be charged, selectively: by either DC or AC Voltage and Current. There will be provisions for installation of a framework to mount and support a polar/bi-polar membrane, divider or separator as may be required to enhance special treatment of particular aqueous waste streams. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a fluid control valve comprising a valve housing and a valve body having a peripheral surface slidably supported for movement in an axial direction in the valve housing. A feedback circuit duct is provided in the valve body and has a first end and a second end. The first end communicates with a flow port in the housing and the second end opens at the peripheral surface of the valve body and is capable of exposing a variable opening area to a control chamber in the housing and thereby subjecting the valve body to said movement by a resulting difference between pressure dependant forces acting on opposite surfaces of the valve body. The invention also relates to a valve body for such a fluid control valve.
BACKGROUND
[0002] A prior art valve of this type is the Valvistor® hydraulic feedback valve. The valve body of such valve is capable of amplifying a small pilot flow through the feedback duct that forms part of a pilot circuit. The second end of the feedback circuit duct comprises an axially extending constant-width slit through the peripheral surface of the valve body. In a prior art embodiment of a Valvistor® valve, the second end opening to the peripheral surface has shape of an inverted keyhole, i.e. a constant-width slit that has a downward widened portion of a circular shape. The circular widened portion does not, however, appear to participate in controlling the feedback flow, i.e. will not be exposed to the control chamber before the valve body engages a mechanical end stop in the valve housing, and is possibly a bore pre-drilled by manufacturing purposes to facilitate the subsequent shaping of the constant-width slit. If the widened end portion were exposed to the control chamber prior to end stop engagement it would possibly only have the function of retarding the valve body before said engagement, with no other specific control function.
[0003] The pilot flow may be controlled by a pilot valve in a manner that the valve body follows the movements of a pilot valve body in the pilot valve. In a basic configuration according to FIG. 1A of the accompanying drawing, the Valvistor® will usually have a proportional output to input characteristic as depicted by the full line 1 A in the diagram of FIG. 2 .
[0004] In many applications, however, for example when controlling heavy machinery such as excavator scoops with high precision by manual joy stick operation, it is desired to have a more progressive characteristic as depicted by the dotted line 1 B in FIG. 2 . This is made possible in a known manner by 1) modifying the poppet type valve to a combination of a poppet type and a spool type valve as shown in FIG. 1B , and 2) forming a saw-tooth pattern on the closing edge of the valve in order to control the flow initially very slowly in a progressive manner until the vertices of the saw-teeth leave the inlet opening in the valve housing. The jagged or saw-tooth edge of the valve body is, however, difficult to machine and therefore adds to the cost of the valve.
DISCLOSURE OF THE INVENTION
[0005] An object of the invention is to provide a fluid control valve of the Valvistor® type that can be implemented with a desired characteristic in a simplified manner.
[0006] This is obtained by the features of the appended claims.
[0007] In an aspect of the invention, the second end of the feedback circuit duct comprises an aperture having a peripheral width that varies at least over a portion proximate to the control chamber of an axial length of the aperture exposable to the control chamber. Thereby, the characteristic of the valve body can be governed by small, low cost measures of the metering aperture of the feedback duct. More precisely, the constant-width slit of the prior art that exposes the variable opening area to the control chamber may easily be replaced by an aperture formed to any shape that varies in the opening direction, for example by electro discharge machining. In the context of the following description and appended claims, the portion proximate to the control chamber may well be understood as to extend at least over the half of the axial length of the aperture exposable to the control chamber.
[0008] Specifically, the aperture width may start varying from an aperture end proximate to the control chamber.
[0009] In one embodiment of the invention, the width of the opening area is decreasing in an axial direction of the valve body opening the valve. In that case the valve will be capable of having, for example, a progressive output flow to input signal characteristic. For example, if the aperture is shaped as a triangle having an apex pointing away from the opening direction of the valve body, the characteristic will follow approximately a quadratic curvature, initially presenting a very small derivative, which may be of importance when controlling high loads with high precision. Generally, widening the aperture will decrease the derivative of the characteristic and vice versa.
[0010] In another embodiment, the width of the opening area is increasing in the axial direction of the valve body opening the valve, for example by using a triangular aperture where an apex is pointing in the opening direction of the valve body. This will give a regressive characteristic that may be useful in certain applications.
[0011] In applications with no specific requirements to desired output to input characteristics, the single aperture can have a circular shape. The aperture may then be formed by a low cost drilling operation.
[0012] In still another embodiment, the second end of the feedback circuit is composed of a plurality of apertures. In that case, the apertures can also be formed by drilling circular bores from the peripheral surface of the valve body into the adjoining remainder of the feedback duct of the valve body. The apertures may then also overlap each other in the axial direction.
[0013] The apertures can also be mutually spaced around the peripheral surface. This may have a balancing influence on the valve body from fluid pressure forces in the apertures.
[0014] Other features of the invention may be evident from the following detailed description and the claims.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIGS. 1A and 1B are diagrammatic sectional views with parts broken away of known embodiments of valves of the Valvistor® hydraulic feedback type;
[0016] FIG. 2 is a graph showing typical characteristics of the respective valves shown in FIGS. 1A and B;
[0017] FIG. 3 is a broken away view, partly in section, of a valve according to the invention;
[0018] FIG. 4 is a view corresponding to FIG. 3 of a modified valve according to the invention;
[0019] FIGS. 5 and 6 are side views from above and below of respective valve bodies according to the invention;
[0020] FIGS. 7 through 13 are broken away views showing different configurations of valve body feedback apertures; and
[0021] FIG. 14 is a spread-out view of a peripheral surface of a valve body having peripherally distributed feedback apertures according to the invention.
[0022] In the different embodiments of valves shown on the drawing, elements with similar functions are throughout designated by the same reference numerals.
DETAILED DESCRIPTION OF EMBODIMENTS
[0023] The fluid control valves 10 shown on the drawing are typically hydraulic power control valves comprising a valve housing 12 and a valve body 30 slidably received in the valve housing 12 for controlling a main flow Q of a pressurized fluid between an inlet port 14 and an outlet port 16 defined in the valve housing 12 . The flow closing and opening end of the valve body 30 may optionally and independent of the invention be of different types: In the prior art embodiment of FIG. 1A , the valve body 30 is of a poppet seat valve type having a frusto-conical closing end. In the prior art embodiment of FIG. 1B , the valve body 30 is of a combined poppet and spool type having a serrated or saw-tooth shaped closing end as mentioned in the foregoing. In the exemplary embodiment of FIGS. 3-6 according to the invention the valve body 30 is of the seat valve type, having a disc-shaped closing member 36 . Accordingly, embodiments of the valve body of the invention may have any suitable type of closing end for the main flow.
[0024] The valves are further of the Valvistor® hydraulic feedback type. In the exemplary embodiments of this type of valve, modified according to the invention and shown on FIGS. 3 and 4 , a small flow q of a feedback control circuit may be controlled by a pilot valve such as the pilot valve 50 shown on FIGS. 1A and 3 .
[0025] The feedback control circuit extends as follows from the inlet port 14 :
[0026] 1) into a feedback duct 38 in a first end 40 of the valve body 30 ;
[0027] 2) out of a second end of the feedback duct 38 , forming an aperture 42 in a peripheral surface 32 of the valve body 30 , wherein the aperture 42 has a variable opening area A ( FIGS. 3 , 4 and 7 ) presented above a metering edge 18 defined in a control chamber 20 of the valve housing 12 ;
[0028] 3) into the control chamber 20 ;
[0029] 4) from the control chamber 20 and into the pilot valve 50 ;
[0030] 5) out of the pilot valve 50 and into the outlet port 16 via a line 54 extending from the pilot valve 50 .
[0031] In the reversed-flow embodiment of FIG. 4 according to the invention, the inlet and outlet ports 14 , 16 are interchanged. The line 54 of the feedback control circuit will then open into the port 16 that is now located axially below the valve body 30 . In this case, the first end 40 of the valve body 30 opens at the valve stem 34 into inlet port 14 .
[0032] As indicated in FIGS. 3 and 4 , the valve stem 34 can have a relatively small diameter for allowing the bottom face of the disc-shaped closing member 36 to resiliently adapt to the opposite face of the valve housing 12 in the valve closing position. Thereby the closing faces need not be machined to perfect parallelism.
[0033] In the embodiments of FIGS. 3 and 4 the valve body 30 is also in a known manner received in a separate element 13 forming part of the valve housing 12 and in turn received in a main valve block of the valve housing 12 .
[0034] The operation of the valve 10 according to the embodiment shown on FIG. 3 is approximately as follows:
[0035] Initially, the valve body 30 closes the passage between the inlet and outlet ports 14 , 16 . The pressure in the outlet port 14 is communicated to the control chamber 20 via the feedback duct 38 and a small opening area A exposed over the metering edge 18 . As the cross sectional area of the valve body 30 presented to the pressure is larger in the control chamber 20 than in the inlet port, and the pressure acting on the remaining cross sectional area presented in the outlet port 16 of the valve body 30 is comparatively low, the valve body 30 remains seated in the closed state.
[0036] If needed, however, embodiments of the invention can be provided with one or more springs (not shown) such as helical compression springs in the control chamber 20 to assist movement of the valve body 30 in the closing direction. Recesses 48 ( FIG. 5 ) may then be provided in the valve body 30 to accommodate such springs.
[0037] To open the valve 10 , an input signal i, for example an electric current, moves a valve spool 52 via a solenoid in the pilot valve 50 from the closed position as shown in FIG. 1 to the right, into a gradually opened position. To this end, it is also possible to use an inverted pilot valve, i.e. a pilot valve that is normally open and closes gradually when influenced by the input signal (not shown).
[0038] The control chamber 20 is thereby opened to the outlet port 16 that has a lower pressure than that in the inlet port 14 . The pressure in the control chamber 20 then decreases resulting in the valve body 30 moving upwards into the control chamber 20 and opening the inlet port 14 to the outlet port 16 . The pressure in the control chamber 20 will then adjust to a level between the pressures in inlet 14 and outlet 16 , resulting in the valve body 30 being balanced by equal opposite forces. By appropriate design of the valve 10 , including the aperture 42 , the valve body 30 will thereby be capable of remaining in the degree of opening determined by the degree of opening of the pilot valve 50 .
[0039] If the pilot valve is further opened, the pressure again decreases in the control chamber 20 resulting in the valve body 30 moving further into the control chamber 20 . The aperture 42 will now present a larger opening area A that is capable of equalizing the forces acting at the opposite cross sections of the valve body 30 at a higher rate of the small feedback control flow q, resulting in that the valve body remains in its new position further into the control chamber 20 .
[0040] The operation described above is reversible so that the valve body 30 will invariably follow the movements of the pilot valve spool 52 in a master-slave manner.
[0041] As already mentioned in the foregoing, a basic embodiment of the prior art Valvistor® valve, as exemplified in FIG. 1A , is capable of performing a proportional input to output characteristic shown by line 1 A in FIG. 2 . This is because the slit 42 in this case by definition has a constant peripheral width, presenting an area over the metering edge 18 that varies proportionally to the movement of the valve body 30 . A prior art modified embodiment of the Valvistor® valve, as exemplified in FIG. 1B , is capable of performing a progressive output to input characteristic shown by curved line 1 B in FIG. 2 ; only, however, by modifying the main flow controlling end of the valve body 30 .
[0042] In the embodiments according to the invention shown on FIGS. 3-12 , the characteristic of the valve can be modified by giving the feedback aperture 42 of the valve body 30 a peripheral width w that varies in a desired manner in an axial direction of the valve body 30 .
[0043] Thereby the opening area A—as well as the resulting valve characteristic—presented over the metering edge 18 , does not vary in the proportional linear manner in response to the movement of the valve body 30 . For example, if the aperture 42 has the shape of a triangle having a base closest to the control chamber 20 and parallel to the metering edge, as shown in FIGS. 3 , 4 , and 7 , the opening area A will not increase proportionally to the opening movement of the valve body 30 but in a progressive manner corresponding to a square function as shown by the curved initial section of characteristic line 1 B of FIG. 2 .
[0044] The height or exposable length h ( FIG. 7 ) of the aperture 42 will determine the attainable movement or opening degree of the valve body 30 . The movement may also be delimited by a surface 21 opposing the valve body 30 in the valve housing 12 . In a manner not shown, this surface may alternatively be defined by the top end of the control chamber 20 . The aperture 42 may, however, for example by manufacturing purposes, also have an inoperative remaining, lower or bottom portion that is never exposed to the control chamber 20 and therefore may have any size or shape. In a modified embodiment of the valve shown in FIG. 4 the remaining lower portion of the aperture 42 may be formed as a slit (not shown) extending axially along the peripheral surface 32 and into communication with port 14 to thereby replace duct 38 .
[0045] The rate of progress of the valve characteristic curve may possibly be varied by varying the width to height ratio of the aperture. Specifically, by varying the apex angle of the triangle, a larger apex angle, for example, will extend the characteristic curve in the horizontal direction.
[0046] If the triangular aperture 42 is defined by convex opposite sides, as illustrated in FIG. 8 , the characteristic curve will be somewhat extended in the vertical direction as compared to the characteristic curve of a corresponding triangular aperture having linear opposite sides.
[0047] If the triangular aperture 42 is reversed, as illustrated in FIG. 9 , the characteristic curve will have a regressive characteristic, initially exhibiting a steep output to input valve characteristic curve.
[0048] Further, the width need not necessarily vary over the full height of the aperture: As indicated in phantom on FIG. 7 , a lower section 46 of the aperture 42 may alternatively still have a constant width in the different embodiments and may also extend downwards beyond the attainable height h as discussed above. The variation of width, however, is always present at an initial or control portion of an axial length of the aperture 42 exposable to the control chamber 20 .
[0049] In the embodiment of FIG. 10 the aperture 42 has a constant width that varies stepwise in the axial direction, and in the embodiment of FIG. 11 the aperture has a beginning short constant width and a following and ending linearly decreasing width. In these examples valve can have two modes: 1) An initial, flat characteristic, fine-tunable mode and 2) a remaining, steep characteristic mode responding fast to pilot valve operation.
[0050] In applications with no specific demands on output to input characteristic, the single aperture 42 can alternatively have a circular shape as shown on FIG. 12 . The aperture may then be formed by a low cost drilling operation.
[0051] As illustrated in FIGS. 5 , 6 , 13 and 14 , the feedback channel 38 can also have a plurality 42 of apertures 44 spaced in a manner over the peripheral surface for obtaining a desired valve characteristic. The apertures 44 can but need not necessarily be circular bores obtained, for example, by drilling. The apertures 44 may also overlap each other in the axial direction of the valve body 30 . If the apertures 44 are evenly distributed over the periphery, as indicated in FIG. 14 , they may assist in centering the valve body 30 in the supporting housing by balancing the radial offset forces resulting from fluid pressure in the apertures 44 .
[0052] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom. Modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention or the scope of the appended claims. | A fluid control valve ( 10 ) comprising a valve housing ( 12 ), a valve body ( 30 ) having a peripheral surface ( 32 ) slidably supported for movement in an axial direction in the valve housing and a feedback circuit duct ( 38 ) in the valve body. The feedback circuit duct has a first end ( 40 ) communicating with a flow port ( 14 ) in the housing and a second end ( 42 ) opening at the peripheral surface ( 32 ). The second end is capable of exposing a variable opening area (A) to a control chamber ( 20 ) in the housing and thereby subjecting the valve body to said movement by a resulting difference between pressure dependent forces acting on opposite surfaces of the valve body. According to the invention, the second end comprises an aperture ( 42 ) having a peripheral width (w) that varies at least over a portion proximate to the control chamber of an axial length of the aperture exposable to the control chamber. | 5 |
FIELD
[0001] The invention relates to methods to control the delivery of fluids for use in oilfield applications for subterranean formations. More particularly, the invention relates to controlling the fluid temperature.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] This invention relates to fluids used in treating a subterranean formation. The pumping of treatment fluids, such as acids or other types of fluids and chemicals is routinely conducted in oil and gas production wells and in water injection wells to enhance either hydrocarbon production or water injection. During the injection of the treatment, the fluids flow down the wellbore and reach the target geological zones at a certain downhole injection temperature which depends on many factors such as the surface temperature, the initial geothermal profile between the surface and downhole, the pump rate, the geometry of the wellbore and the thermal properties of the fluids, completion materials, and rocks in the subterranean formations. Control of the downhole injection temperature is desirable to efficiently tailor the effectiveness and other parameters of the treatment.
SUMMARY
[0004] Embodiments of the invention provide methods and apparatus for using a fluid within a subterranean formation comprising forming a fluid comprising a fluid additive, introducing the fluid to a formation, observing a temperature, and controlling a rate of fluid introduction using the observed temperature, wherein the observed temperature is lower than if no observing and controlling occurred. Embodiments of the invention provide methods and apparatus to deliver fluid to a subterranean formation comprising a pump configured to deliver fluid to a wellbore, a flow path configured to receive fluid from the pump, a bottom hole assembly comprising a fluid outlet and a temperature sensor and configured to receive fluid from the flow path, and a controller configured to accept information from the temperature sensor and to send a signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic diagram of surface equipment and a bottom hole assembly.
[0006] FIG. 2 is a schematic diagram of details of a bottom hole assembly.
[0007] FIG. 3 is a flow diagram of a process of embodiments of the invention.
[0008] FIG. 4 is a plot of the Joules Thompson coefficient as a function of pressure and temperature for carbon dioxide.
[0009] FIG. 5 is a plot of temperature variation in the gas phase as a function of pressure and temperature for carbon dioxide.
[0010] FIG. 6 is a plot of temperature variation of the mixture during the JT effect as a function of pressure and temperature for carbon dioxide.
[0011] FIG. 7 is a plot of the temperature in the gas phase as a function of pressure and temperature for carbon dioxide.
[0012] FIG. 8 is a plot of temperature variation of the mixture during the JT effect as a function of pressure and temperature for carbon dioxide.
[0013] FIG. 9 is a plot of the temperature in the gas phase as a function of pressure and temperature for carbon dioxide.
[0014] FIG. 10 is a plot of temperature variation of the mixture during the JT effect as a function of pressure and temperature for carbon dioxide.
DETAILED DESCRIPTION
[0015] The procedural techniques for pumping fluids down a wellbore to fracture a subterranean formation are well known. The person that designs such treatments is the person of ordinary skill to whom this disclosure is directed. That person has available many useful tools to help design and implement the treatments, including computer programs for simulation of treatments.
[0016] In the summary of the invention and this description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific numbers, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors have disclosed and enabled the entire range and all points within the range. All percents, parts, and ratios herein are by weight unless specifically noted otherwise.
[0017] Temperature control along a surface of a subterranean formation is important when acid is injected into the reservoir rock around the wellbore to increase production rate. The acid efficiency depends on the acid temperature and it may be desirable to decrease the downhole injection temperature to ensure better acid performance. Another example is the determination of the geological zones that are accepting the injected fluid and those that are not which may be achieved by using distributed temperature sensors (DTS). If the downhole injection temperature is sufficiently low/high, then zones of higher injectivity will show larger warmback/cooldown times if the well is shut in after the treatment. The warmback/cooldown time is the time it takes during the shut-in for the temperature of a given zone to come back to its original value before treatment. The measure of the warmback/cooldown time becomes more accurate if the downhole injection temperature is lower/higher than otherwise achieved.
[0018] One means of changing the downhole injection temperature is to expose the fluid to a pressure drop caused by fluid expansion. The laws of thermodynamics predict that, under such a process, fluids may either reduce or increase their temperature through an effect named the Joule Thomson (JT) effect. Embodiments of the invention relate to a method of controlling downhole injection temperature by taking advantage of this effect through the combined use of pump rate, a bottom hole assembly (BHA), additives to the fluids and downhole temperature sensors.
[0019] For certain types of applications, the functionality and the performance of the injected fluid may depend on the downhole injection temperature. In other types of applications, it may be desirable to modify the downhole injection temperature in such a way that some downhole measurements used for interpreting the treatment fluid performance may be optimized. The JT effect and its influence on the downhole temperature during the production of reservoir fluids have been investigated by many authors. However, the controlled use of the JT effect to accomplish the goal of changing the downhole injection temperature of the injected fluid for a given purpose has not been pursued historically.
[0020] Historically, a method changes the temperature of the fluid in the wellbore using the JT effect of a gas that would change the temperature of a heat exchanger. The wellbore fluid flowing in contact with the heat exchanger would have its temperature changed by heat transfer between the heat exchanger and the wellbore fluid. The method proposed here is significantly different as it uses the JT effect of the injected fluid itself and therefore does not require a heat exchanger. Historical methods do not deal with changing the downhole injection temperature to control the functionality of the injected fluid and only measure its properties.
[0021] The JT effect can occur during the production of a gas when the later experiences a significant pressure drop when going from the reservoir rock into the well. In most situations, the gas will experience a temperature drop during the pressure drop. This temperature drop may be detected by downhole temperature gages, such as those on production logging tools or distributed temperature sensors and may help an engineer identify the regions along the wellbore from which gas is being produced. Additionally, as the gas moves up to the surface production facility, its pressure will decrease and the JT effect will often result in a reduced gas temperature.
[0022] Additional embodiments of the invention control a temperature change during injection, into the well through the JT effect. Methods comprise using a tool and a control process which can be used for changing the downhole injection temperature through the JT effect during the pumping of a fluid treatment in a well.
[0023] If it is estimated or known by measurement that the fluid being pumped for a specific purpose, such as reservoir stimulation, chemical treatment, and enhanced oil recovery, does not have the required downhole injection temperature, either for its own performance or for the accuracy of the downhole temperature-based interpretation of the treatment performance, placing a device along its flow path will cause a pressure drop in the fluid. This pressure drop will change the downhole injection temperature through the JT effect. By being able to measure or predict the down hole injection temperature and to control the pump rate, the down hole injection temperature may be adjusted to the required temperature. The down hole injection temperature response to the pump rate may also be enhanced by introducing fluid additives, such as gases, to the pumped fluid.
[0024] The method has two parts:
1. The Tool: The physical device and products that cause a change in the down hole injection temperature 2. The Control Process: The methodology for optimizing the use of the tool
[0027] A down hole injection temperature change may be achieved by three means:
1. The characteristics of the bottom hole assembly 2. The value of the pump rate 3. The use of fluid additives
[0031] For instance, the fluid may be pumped from the surface through a tubing or coiled-tubing at the end of which a bottom hole assembly may be placed. On the bottom hole assembly, a temperature sensor may be mounted. The ensemble formed by the pump, the flow path, typically the drill pipe or coiled tubing, the bottom hole assembly, the temperature sensor, and the fluid additives, is referred as the tool and is used as part of the method. The bottom hole assembly of the tool may have some remotely controlled flow devices or orifices which, for a given pump rate, may control the pressure drop that the fluid will undergo when leaving the bottom hole assembly into the wellbore before flowing into the reservoir. The down hole injection temperature may also be monitored using downhole temperature sensors not mounted on the bottom hole assembly. For instance, the down hole injection temperature may be measured using down hole temperature sensors deployed in the wellbore before or during the pumping. Finally, if down hole temperature sensors are not available, the down hole injection temperature may be predicted using a mathematical model capable of solving the relevant thermodynamics problem for the treatment fluid undergoing expansion through the controlled flow devices or orifices.
[0032] Using the down hole injection temperature data measured by the temperature sensors on the bottom hole assembly, or measured with other down hole temperature sensors, or predicted by the model, some adjustment of the pump rate and of the tool may be decided during the pumping. This decision tree is referred as the control process and is the second part of the method. It is illustrated in FIG. 4 . For instance, the controlled flow devices may be valves which can be closed or open to increase or reduce the pressure drop. Additionally; the fluid additive may be a gas that is pumped with the fluid to optimize the value of the JT coefficient of the gas-fluid mixture. Alternatively, gas on its own may be pumped towards the end of the treatment for further control on the down hole injection temperature through increased JT effect.
[0033] A combined use of the tool and the control process will help engineers ensuring that the down hole injection temperature meets the requirements.
[0034] FIG. 21 illustrates one embodiment of the mechanical equipment that may be used. The pumping is performed using a fluid pump 101 on surface 102 . The treatment fluid and the fluid additive are stored in their own fluid tanks 103 and 104 and flow through the pump 101 at a rate and proportion controlled by the engineer. The mixture, formed by the treatment fluid and the fluid additive, then flows through surface lines 105 and then down into the wellbore 107 through a flow path 106 , typically production tubing, the casing, a drill pipe, or coiled tubing. At the end of the flow path 106 , the fluid enters the bottom hole assembly 108 . The bottom hole assembly 108 has multiple orifices 109 that may be closed or open remotely by the engineer. When flowing though an orifice, as represented in FIG. 3 , the fluid undergoes a pressure drop. The extent of the pressure drop is controlled by the following.
The pump rate The number of orifices open to flow The amount of fluid additive
[0038] The pressure drop causes the fluid to undergo a change in down hole injection temperature as it leaves the bottom hole assembly 108 and flows into the reservoir 111 . This change in down hole injection temperature may be monitored at the surface by using the temperature reading from temperature sensors 110 through wireline communication or fiber optic cable. Alternatively, the down hole injection temperature may be obtained by other down hole temperature sensors (not shown) such as a distributed temperature sensors or be predicted by a mathematical model. In any event, controller 112 may receive a signal from or send a signal to the bottom hole assembly, temperature sensor, pump, additive or fluid tanks, or lines connecting the tanks, pump, flow path, or assembly. Finally, the engineer may change some of the above three parameters to optimize the down hole injection temperature.
[0039] FIG. 2 is a schematic diagram of details of a bottom hole assembly 108 in a wellbore 107 . The fluid flows through the flow path 106 to the assembly 108 with a pressure drop illustrated by flow lines 201 . FIG. 2 shows flow lines 201 are present on open valves 202 , but not on closed valves 203 . Temperature sensors may also be placed across the surface of or embedded in or suspended near the assembly 108 .
[0040] In the case where the down hole injection temperature must be controlled for the accuracy of the down hole temperature-based interpretation of the treatment performance, it is also possible to pump another fluid than the treatment fluid, on its own, in order to achieve the required down hole injection temperature. For instance, if it is estimated that, under the conditions under consideration, the down hole injection temperature may not be controlled by pumping the treatment fluid, another fluid may be pumped at some stages in order to achieve the required down hole injection temperature for some time and to allow more accurate interpretation. For instance, at the end of an acid treatment, a gas may be pumped after the acids to achieve a larger change on the down hole injection temperature. This larger change on the down hole injection temperature will allow a more accurate interpretation concerning the event associated with the gas injection, which may be a direct consequence of the treatment performance. For instance, after having pumped the acid, the inflow profile along the well is what determines the acid treatment performance. Pumping a gas after the acid, with an optimum down hole injection temperature will reveal the inflow profile during gas injection. The inflow profile during gas injection being a consequence of the performance of the acid, the acid performance may be estimated. After pumping the gas, the pump rate is set to zero and the well is shut-in while a distributed temperature sensor is logged. Looking at how fast the down hole temperature at a given depth warms back to the temperature before the treatment reveals how much was injected. Alternatively, the position of a gas slug, with a lower down hole injection temperature along the well may be monitored by distributed temperature sensors revealing which zones are accepting fluid during the pumping. The use of temperature logging such as distributed temperature sensors or a down hole temperature on a moving tool as a means to identify injectivity profiles based on a down hole injection temperature significantly different from the reservoir temperature is important to some embodiments.
[0041] The following thermodynamic calculations may be performed to determine the down hole injection temperature as a function of the above three parameters. These calculations validate the concept of the use of the JT effect and may be used as a means of predicting the down hole injection temperature change with the pressure drop. The value of the pressure drop that the fluid will undergo when flowing through the orifices can be determined using Equation (1) and Equation (2):
[0000]
PD
=
1
2
c
2
(
1
-
β
4
)
ρ
F
(
V
)
2
(
1
)
β
=
d
u
d
o
,
V
=
PR
A
d
=
PR
1
4
n
o
π
d
0
2
(
2
)
PD is the Pressure prop (Pa)
V is the fluid flow velocity (m/s)
c is the dimensionless discharge coefficient
d u Is the upstream diameter (m)
d o is the orifice diameter (m)
ρ F is the fluid density (kg/m 3 )
A d is the surface flow area formed by all n o open orifices (m 2 )
n o is the number of orifices open to flow
[0050] If the fluid additive is a gas, the two fluids will undergo a different pressure drop, PD F for the treatment fluid and PD G for the gas, as described by Equation (3) and Equation
[0000]
PD
G
=
1
2
c
2
(
1
-
β
4
)
ρ
G
(
Vq
)
2
.
(
4
)
[0000]
PD
F
=
1
2
c
2
(
1
-
β
4
)
ρ
F
(
V
(
1
-
q
)
)
2
(
3
)
PD
G
=
1
2
c
2
(
1
-
β
4
)
ρ
G
(
Vq
)
2
(
4
)
q is the volume fraction of gas in the mixture formed by the fluid and the gas
ρ G is the gas density (kg/m 3 )
[0053] In the general case where the FA is a gas, both fluids phases will undergo a change in down hole injection temperature, denoted DT F for the treatment fluid and DT G for the gas additive, as given by Equation (5) and Equation (6).
[0000]
DT
F
=
∫
BHP
+
DP
F
BHP
η
F
(
p
,
T
F
)
p
(
5
)
DT
G
=
∫
BHP
+
DP
G
BHP
η
G
(
p
,
T
G
)
p
(
6
)
DT G is the temperature variation in the gas phase (K)
DT F is the temperature variation in the fluid phase (K)
η G is the gas Joule-Thomson coefficient (K/Pa)
η F is the treatment fluid Joule-Thomson coefficient (K/Pa)
BHP is the DH pressure in the wellbore (Pa)
T G is the temperature in the gas phase (K)
T F is the temperature in the fluid phase (K)
p is the pressure (Pa)
[0062] The final value of the down hole injection temperature of the mixture formed by the treatment fluid and the gas can be determined using Equation (7).
[0000]
DHIT
=
T
I
+
DT
GF
=
T
I
+
q
ρ
G
C
pG
(
T
I
+
DT
G
)
+
(
1
-
q
)
ρ
F
C
p
F
(
T
I
+
DT
F
)
q
ρ
G
C
pG
+
(
1
-
q
)
ρ
F
C
p
F
(
7
)
DHIT is the DH Injection Temperature (K)
DT GF is the temperature variation of the mixture during the JT effect (K)
C pG is the heat capacity of the gas (J/(kg K))
C pF is the heat capacity of the fluid (J/(kg K))
T I is the initial temperature of the mixture in the BHA, before flowing through the orifices (K)
[0068] The physical and thermodynamic properties of the treatment fluid and the gas, ρ F , ρ G , C pG , C pF , C pG , η F , η G , are functions of the temperature and pressure. It is possible to determine those properties from an equation of state. An equation of state links the value of the fluid density, fluid temperature and pressure together. The determination of an equation of state for a given fluid or gas has been the subject of a vast amount of literature. For instance, an equation of state such as the one from R. Span and W. Wagner, “A New Equation of State for carbon Dioxide Covering the Fluid Region from the Triple-Point to 1100K at Pressures up to 800 MPa”, J. Phys. Chem. Ref Data, 25(6), 1996 may be used for carbon dioxide.
[0069] It is also possible to determine physical and thermodynamic properties of the treatment fluid and the gas, η F , η G , C pG , C pF , C pG , η F , η G from experiments. Some of such experiments demonstrate the ability of certain fluids to undergo a temperature change during a JT effect. It is understood that during expansion, a fluid may experience heating, for a negative JT coefficient, or cooling for a positive one, and the scientific and technical literature provides numerous examples of the experimental values of the JT coefficient for numerous fluids. For instance, in J. R. Roebuck, H. Osterberg, “The Joule-Thomson Effect in Nitrogen”, Physical Review, 48, 1935, and J. R. Roebuck et al, “The Joule-Thomson Effect in Carbon Dioxide”, J. Am. Chem. Soc., 64, 1947, the values of the JT coefficient have been measured experimentally for nitrogen, and carbon dioxide, under various conditions in temperature and pressure, and the experimental data reported in these references, respectively, show that the JT coefficient may be positive or negative, highlighting zones of cooling and zones of heating respectively for these fluids.
[0070] The method is now illustrated in the case where the treatment fluid is an aqueous acid and the fluid additive is carbon dioxide (CO 2 ). Considering a 15 weight percent hydrochloric acid (15% HCl) solution being pumped with CO 2 with a down hole foam quality q equal to 0.5, the down hole injection temperature may be determined using Equations (1) to (7) and by using an equation of state for CO 2 as follows. First, and for the purpose of this example, the treatment fluid, 15% HCl, being a liquid, the variations of ρ F , C pF , and η F , during the flow through the orifices are negligible. The following values are reasonable approximations:
[0000]
ρ
F
=
1070
kg
/
m
3
,
C
p
F
=
4200
J
/
(
kg
F
)
,
η
F
=
-
1
ρ
F
C
p
F
=
-
2.23
×
10
-
7
K
/
Pa
(
8
)
[0071] For CO 2 , the determination of DT G requires computing Equation
[0000]
DT
G
=
∫
BHP
+
DP
G
BHP
η
G
(
p
,
T
G
)
p
(
6
)
[0000] along the expansion path experienced by the gas. This may be done using numerical approximations as described by Equations (9) to (13) as, typically, the equation of state is a too complex formula to allow the integration in Equation (6) to be done by hand.
[0000]
DT
G
=
lim
N
->
∞
[
∑
i
=
1
,
N
[
δ
p
N
C
pG
(
p
i
,
T
Gi
)
(
T
Gi
∂
v
∂
T
(
p
i
,
T
Gi
)
-
v
G
(
p
i
,
T
Gi
)
)
]
]
(
9
)
v
G
(
p
i
,
T
Gi
)
=
1
ρ
G
(
p
i
,
T
Gi
)
(
10
)
δ
p
N
=
PD
N
(
11
)
p
i
=
p
i
-
1
+
δ
p
N
(
12
)
T
Gi
=
T
Gi
-
1
+
[
δ
p
N
C
pG
(
p
i
-
1
,
T
Gi
-
1
)
(
T
Gi
-
1
∂
v
∂
T
(
p
i
-
1
,
T
Gi
-
1
)
-
v
G
(
p
i
-
1
,
T
Gi
-
1
)
)
]
(
13
)
[0072] Equations (9) to (13) can be solved using a large value for N. This large value N may be determined by solving Equations (9) to (13) with increasing values of N until the result does not change significantly when N becomes larger. To solve Equations (9) to (13), it is possible to specify the final value of the pressure during the expansion, bottom hole pressure and the initial temperature in the bottom hole assembly before the expansion, T I .
[0000] T G1 =T I (14)
[0000] P N =BHP (15)
[0073] Equations (9)-(15) solve the temperature evolution in the gas as it expands by expanding the gas by very small expansion steps and adding the effect of all the smaller steps until the final pressure drop is reached. To be able to do so, the determination of the specific volume ν G must be detailed. This requires the use of an equation of state for CO 2 . Typically, an equation of state provides an explicit expression of the pressure, given a value of the temperature and specific volume ν G :
[0000] p=EOS (ν G ,T G ) (16)
[0074] However, determining ν G from the values of p and T G requires solving a non-linear equation. This may be done easily by using conventional optimization algorithms such as the Newton method or the dichotomy method.
[0075] The problem consisting of solving Equations (9)-(16) has been solved using the equation of state from R. Span and W. Wagner [4]. FIG. 8 illustrate the values of DT G as a function of the final pressure after expansion (BHP) and the initial temperature before expansion T I . In FIG. 5 , the value of η G is plotted for various values of pressure and temperature. The fact that η G is positive over a wide range of pressure and temperature shows that CO 2 cools down under the JT effect. Solving Equations (9) to (16), the changes of temperature in the gas (DT G ) and in the mixture (DT GF ) are plotted in FIG. 6 and FIG. 7 , respectively, for a value of pressure drop of −1000 PSI. Increasing the pressure drop to −2000 PSI, the fluids cool down further as plotted in FIG. 8 and FIG. 9 but the area affected by the cooling does not vary significantly. It can also be seen that the cooling of the gas is larger than the cooling of the mixture. Depending on the situation, gas alone may therefore be pumped for maximum cooling. It may also be seen that the pressure drop must be large enough for significant cooling to occur. When pressure drop=−100 PSI, the temperature change is much smaller ( FIG. 10 and FIG. 11 ) and therefore, if the engineer aims at cooling down by 5K, the pump rate and the controlled flow device must be controlled in such a way the pressure drop is closer to −1000 PSI.
EXAMPLES
[0076] The following examples are presented to illustrate the preparation and properties of fluid systems, and should not be construed to limit the scope of the invention, unless otherwise expressly indicated in the appended claims. All percentages, concentrations, ratios, parts, etc. are by weight unless otherwise noted or apparent from the context of their use.
[0077] FIG. 4 plots the value of the JT coefficient η G for CO2 as a function of pressure and temperature.
[0078] FIG. 5 plots the DT G for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −1000 PSI. Data truncated between −5K and +5K.
[0079] FIG. 6 is a plot of DT GF for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −1000 PSI. Data truncated between −5K and +5K. FIG. 7 is a plot of DT G for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −2000 PSI. FIG. 8 is a plot of Data truncated between −5K and +5K. FIG. 8 plots DT GF for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −2000 PSI. Data truncated between −5K and +5K. FIG. 9 is a plot of DT G for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −100 PSI. Data truncated between −5K and +5K. FIG. 10 is a plot of DT GF for CO2 for various initial temperature T I and pressure after JT effect (BHP) with a PD equal to −100 PSI. Data truncated between −5K and +5K
[0080] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. | Methods and apparatus for using a fluid within a subterranean formation comprising forming a fluid comprising a fluid additive, introducing the fluid to a formation, observing a temperature, and controlling a rate of fluid introduction using the observed temperature, wherein the observed temperature is lower than if no observing and controlling occurred. A method and apparatus to deliver fluid to a subterranean formation comprising a pump configured to deliver fluid to a wellbore, a flow path configured to receive fluid from the pump, a bottom hole assembly comprising a fluid outlet and a temperature sensor and configured to receive fluid from the flow path, and a controller configured to accept information from the temperature sensor and to send a signal. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for training an animal, especially a dog, by providing a stimulus to discourage undesired behavior. The invention relates, more particularly, to providing an adjustable stimulus that trains the animal to limit its movement to a prescribed area.
One known technique to discourage a dog (or other animal) from leaving the confines of a yard or field is to attach a collar that delivers an aversive stimulus whenever the dog comes into range of a low-power radio signal broadcast along the perimeter of the yard. That signal can be generated, for example, by a wire "antenna" buried along the perimeter of the yard that is powered by a transmitter, e.g., in the owner's home. A receiver in the collar detects the signal as the dog approaches the perimeter wire and applies, e.g., a mild electric shock or olfactory irritant (such as ammonia gas) to discourage further progress. This can be preceded by a buzzing sound or other auditory warning. In time, the dog learns to turn back simply on hearing the auditory warning and without receiving other stimulus.
One difficulty encountered with the foregoing is radio frequency interference from other sources which may induce the aversive stimulus even when the dog is far from the perimeter, thereby confusing the animal and compromising the effectiveness of the technique. A solution to this problem involves transmitting a coded radio signal, as disclosed in commonly assigned U.S. Pat. No. 5,353,744, to Custer, incorporated by reference herein.
Another difficulty in the technique described above is controlling the parameters of delivery of the stimulus. For instance, it is known that providing different types of stimulus (e.g., shock and/or noise), different rates of stimulus (e.g., frequency of stimulus application) and different intensities of stimulus (e.g., voltage of the stimulus) enhances training efficiency and efficacy. It is likewise known that different animals respond differently to different stimulus types, rates and intensities. For example, a large dog or a dog with an unusual temperament may require a greater stimulus than a small dog or a dog with an average temperament.
Although a user can control certain stimulus parameters by altering the radio signal, this can be problematic since the transmitter is normally located in the owner's residence, some distance away from where the animal is being trained. The owner hardly wants to leave the animal to modify the stimulus parameters every time it is desirable to so. Besides the inconvenience, interrupting the training session may also confuse the animal and make training more difficult.
Environmental conditions present other difficulties. Because the animal may be out frolicking in rain or snow, the collar--and, particularly, its receiver unit--may be subjected to water, wind, mud, dirt, heat and cold. In addition, the receiver may be subjected to physical abuse, if the animal paws at it or rubs it against a tree or rock.
In view of the foregoing, an object of the invention is to provide improved apparatus and methods for training an animal and, more particularly, training a dog or other domesticated beast.
Yet another object of the invention is to provide such apparatus and methods as permit the ready adjustment of stimulus provided to an animal through a collar or other attached device.
Yet another object of the invention is to provide such apparatus and methods as improve the tailored delivery of stimulus to the animal.
Yet still another object of the invention is to provide such apparatus and methods as can be implemented inexpensively.
Yet still a further object of the invention is to provide such apparatus and methods as can be implemented in a rugged and waterproof housing.
SUMMARY OF THE INVENTION
The foregoing objects are among those attained by the invention, which provides in one aspect an apparatus to aid in training an animal. The apparatus includes a housing removably attached to the animal, a transducer mounted to the housing for delivering a stimulus to the animal, and a magnetically actuated switch disposed within the housing. The switch is coupled to the transducer and controls at least one of a type, a rate, and/or an intensity of stimulus delivered by the transducer to the animal.
In a further aspect of the invention, the apparatus also includes a magnet, external to the housing, for actuating the switch. A user actuates the switch by placing the magnet within a reaction zone of the switch and, thereby, generates a command.
A controller, coupled to the switch and to the transducer, interprets that command, e.g., based upon the time period that the switch is actuated. In an alternative aspect, the controller interprets the command based upon the number of times the user actuates the switch by repetitively disposing the magnet within, and removing the magnet from, the reaction zone.
In another aspect, the apparatus further includes a receiver coupled to the controller for receiving a coded radio signal. The radio signal activates delivery of the stimulus to the animal. The radio signal may include commands interpreted by the controller for further controlling any of the type, rate and intensity of stimulus delivered by the transducer to the animal. The controller may include adjustable sensitivity circuitry for defining a threshold strength of the coded radio signal below which delivery of the stimulus is prevented. A transmitter may be provided for generating the coded radio signal through an antenna defining a boundary over which the animal is trained not to cross.
The transducer may include, in still further aspects of the invention, a plurality of electrodes in contact with the animal and the type of stimulus includes an electric shock transmitted through the plurality of electrodes. The transducer also includes a speaker and the type of stimulus includes a noise transmitted through the speaker.
Another aspect of the invention provides an apparatus as described above that includes a watertight housing and a battery mounted to the housing and coupled to the controller for supplying power to the apparatus. The housing further includes a battery cavity and the cavity is sealed with a removable watertight battery cap.
Still further aspects of the invention provide methods for operating an apparatus of the type described above in order to train an animal.
These and other aspects of the invention are evident in the drawings and in the description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are drawings in perspective view of animal control apparatus including a transmitter and a receiver unit according to the present invention.
FIG. 2 is a graphical representation of electrical stimulation regimes according to the present invention.
FIG. 3 is a block diagram showing the electronic operation of the transmitter of the apparatus of FIG. 1A.
FIG. 4 is a block diagram showing the electronic operation of the receiver unit of the apparatus of FIG. IB.
FIGS. 5A and 5B are a schematic of electronic circuitry of the receiver unit.
FIG. 6 is a flow diagram of procedures executed by the electronic circuitry shown schematically in FIGS. 5A and 5B.
DETAILED DESCRIPTION
Introduction
The animal training apparatus of the present invention includes a receiver unit, carried by an animal, that delivers an aversive stimulus to the animal whenever the receiver unit detects a coded radio signal in a field surrounding a boundary wire extending from a transmitter. Signal generating circuitry of the transmitter sends a coded AM radio signal through the boundary wire which operates as a transmitting antenna.
As long as the transmitter power is on, the coded radio signal is continuously sent through the boundary wire setting up a continuous coded field in the vicinity of the wire. The system may thereafter be left unattended. The space established by the field within a threshold distance from the wire provides an avoidance zone for the animal. The receiver unit delivers the aversive stimulus to the animal whenever the animal is within the avoidance zone, and ceases delivering the aversive stimulus when the animal moves back within the prescribed space to escape the avoidance zone.
In the illustrated embodiment, as described in more detail below, certain operating parameters may be controllably selected by a user. These operating parameters include the type, rate and intensity of stimulus delivered to the animal. In these embodiments, the receiver unit is capable of delivering an audible signal alone, an electric shock alone, or an audible signal followed shortly by an electric shock. In other embodiments the rate and intensity of stimulus are controllable locally at the receiver unit. Also, the configuration of the signal sent by the transmitter circuitry through the boundary wire can be selected to provide the operating parameters of the receiver unit. The range of the field (and, hence the size of the avoidance zone) can be adjusted to increase or decrease the distance from the boundary wire at which a threshold for detection by the receiver unit is reached.
Local control of the receiver unit is provided via a switch or switches that allow the operating parameters to be selected proximate to the animal. Again, these operating parameters include type, rate and intensity of stimulus. Furthermore, the switch can be used to control the on/off status of the receiver unit. The switch is actuated when a user brings a magnet within a switch actuation zone outside the receiver unit. This prevents the waterproof housing and/or other environment-resistive features of the receiver unit from being compromised.
General
Referring to FIGS. 1A and 1B, the apparatus includes a transmitter, shown generally at 110 (FIG. 1A), and a receiver unit, shown generally at 120 (FIG. 1B).
As seen in FIG. 1A, transmitter 110 includes electronic circuitry contained in an enclosure 112, which supplies bursts of approximately 8 kHz pulses to a twisted wire, shown at 114 leading away from enclosure 112. The transmitter 110 is typically mounted on a wall indoors to protect it from the elements. The twisted wire 114 is fed through an outside wall 105 to a surge protector 106 which protects the transmitter from electrical surges, especially due to lightning. The surge protector 106 and the transmitter 110 are grounded by grounding wire 107.
The transmitter 110 is provided with a standard alternating current adapter 1 16 so that it can be powered by connection to a standard 110 volt outlet. The A/C adapter 116 is provided with a plug 101 for connection to a power supply jack on the transmitter enclosure 112. Twisted wire 114 is provided at its end with a plug 102 for connection to a wire jack on the transmitter enclosure. The twisted wire 114 leads from plug 102 to a boundary portion of the wire (shown figuratively at 302 in FIG. 1A). The boundary portion of the wire 302 is arranged on the periphery of the space within which the animal is to be confined (or from which the animal is to be excluded), establishing the boundary of the prescribed space.
The transmitter enclosure 112 is provided with a power source on/off switch 111; a shock stimulation rate selector switch 113, which provides for delivery to the animal of either slow or medium or fast shock rates; a type of stimulus selector switch 115, which provides for delivery to the animal (in the "audible-plus-shock" mode) of an audible warning followed by an electric shock stimulation or (in the "audible-only" mode) of an audible warning only; and a range adjuster 117, which provides for adjustment of the strength of the signal field, to increase or decrease the effective width of the avoidance zone.
The width of the avoidance zone can be readily adjusted to distances between about 3 and 12 feet by turning the range adjuster 117 in one direction ("+") to widen the signal field, and in another direction ("-") to narrow it. The range adjuster 117 basically increases the current in the wire 302.
A power indicator light 118 on the front panel of the transmitter enclosure lights when the transmitter is correctly connected to line current through the A/C adapter, the on/off switch is "on", and power is operational.
When the transmitter 110 is connected to a power source and the power source on/off switch 111 is "on", a signal consisting of a series of bursts of pulses, whose parameters can be set (as described below with reference to FIG. 2) using the selectors 113, 115, 117, is continually delivered through the boundary wire, which acts as a transmitting antenna to produce a continuously amplitude-modulated field about the boundary wire 302. Once the boundary wire has been properly installed and plugged into the transmitter, and so long as there is electrical continuity throughout the boundary wire, a loop indicator light 119 lights; if electrical continuity in the boundary wire is broken or if the signal is interrupted, the loop indicator light goes out and an audible alarm sounds.
Turning now to FIG. 1B, the receiver unit 120 includes electronic circuitry contained in a housing 122, which is affixed to a length-adjustable strap 124. The strap 124 is provided with a clasp or buckle 121, so that the receiver unit 120 can be removably mounted onto the animal by encircling the animal's neck with the strap, adjusting the length, and joining the clasp. Electrodes 128 protrude from receiver unit housing 122 so that when the receiver unit 120 is mounted on the animal, the electrodes 128 press against the animal's skin to deliver a shock stimulus to the animal upon activation by the circuitry. Electrodes 128 of different lengths which are readily interchangeable may be used to compensate for the thickness of the animal's fur. Receiver unit 120 is additionally provided with a small loudspeaker (not shown in FIG. 1B) to deliver an auditory stimulus to the animal. The receiver unit is powered by a replaceable battery pack 123, which is received in a battery compartment 126 and held in place by battery cap 125.
The receiver unit housing 122 is preferably watertight and made of material sufficiently rugged to withstand various outdoor environments. The battery cap 125 is threaded and may include a gasket or other sealant (not shown) to provide a watertight enclosure for the battery pack 123. The electrodes 128 are threadably mounted to the housing and include a washer 127 to keep moisture and dirt outside the housing 122.
The receiver unit 120 includes a magnetically actuated switch (not shown in FIG. 1B, but described in greater detail below), preferably located within the housing 122 near a side 129 of the housing.
An actuator 130 includes a magnet 132 at an end thereof and a test light 133 (the test light is more fully described below). When a user places the magnet 132 outside the housing 122 within an "actuation zone" (e.g., 0"-0.5" and, preferably, 0"-2") of the magnetic switch (located near side 129), the magnet 132 will actuate the switch. Thus, the user can locally and externally control operating parameters of the receiver unit 120 by giving commands to the receiver unit by actuating the switch. Furthermore, no additional waterproofing of the housing 122 is required to implement this local control feature.
A user enters commands into the receiver unit by moving the magnet 132 in and out of the actuation zone one or more successive times. As the magnet 132 is placed in that zone, circuitry within the receiver unit 120 measures the period of time during which it actuates the switch. Based upon this time period, certain operating parameters may be set. For example, by placing the magnet in the actuation zone for one second, the receiver unit enters an operational state wherein it will deliver a low intensity stimulus to the animal when it enters the avoidance zone. If the user keeps the magnet near the switch for another second, the receiver unit enters a state wherein a medium intensity level will be delivered to the animal. Another second of actuation will cause the receiver unit to enter a state wherein a high intensity level of stimulus will be delivered. Other series of commands are possible and described more fully below. The receiver unit emits a beep or series of beeps from a speaker to indicate to the user which particular operating parameters have been set.
As the animal enters the avoidance zone, a receiver within the receiver unit 120 detects the field generated about the boundary wire 302. Circuitry within the receiver unit processes the radio signal from the boundary wire to produce appropriate stimuli based upon the commands input from the magnetically actuated switch and the transmitter. For example, when the shock stimulation rate is adjusted to a higher setting using selector switch 113 on the transmitter, the animal receives a greater number of shocks per second. As explained below, the magnet and magnetically actuated switch can also be used to set the stimulation rate, as well as the intensity of stimulus, i.e., the voltage level.
The type selector switch 115 on the transmitter is used to set the type of stimulus, i.e., audible-only or audible-plus-shock. In preferred embodiments, the magnet and magnet switch can be used to set this as well.
A further feature of the receiver unit includes a warning zone before the avoidance zone.
Such a warning zone extends up to an additional five to ten feet from the avoidance zone. When the animal enters the warning zone, only an auditory signal is delivered. If the animal continues beyond the warning zone, however, and proceeds into the avoidance zone, a shock may be delivered. In order for the apparatus of the present invention to provide a warning zone, the controller unit includes circuitry that, upon initial detection of the radio signal, decreases the threshold sensitivity of the controller by some amount, preferably about 5-20%. If the threshold sensitivity reduction prevents the controller from subsequently detecting the radio signal, then the controller concludes that the animal is in the warning zone and provides a warning noise. If instead the controller still detects the radio signal even after the threshold is lowered, then the controller concludes that the animal is in the avoidance zone and provides a shock stimulus. The threshold is reset to normal after the stimulus is delivered.
Stimulus Parameters
Delivery of stimulatory impulses is according to three parameters referred to generally as type, rate and intensity. Preferred apparatus according to the invention delivers aversive stimulation to the animal in a series of stimulatory impulses (auditory "beeps" and/or electric shocks) that continue as long as the animal remains within the avoidance zone, and ceases when the animal leaves the avoidance zone.
The type of stimulus delivered to the animal can include electric shock, audible signals and/or an irritant such as ammonia gas. Preferred apparatus according to the invention is capable of delivering an auditory stimulation (a series of"beeps" audible to the animal) alone, or an auditory stimulation coupled with an electric shock stimulation, in which each of the series of audible beeps is followed by an electric shock.
The rate of stimulus delivered to the animal is the number of stimulatory impulses per second. The stimulus becomes more aversive as the rate of stimulus delivery is increased. A higher rate produces a "stronger" aversive stimulation, and delivery of stimulatory impulses at a lower rate produces a "weaker" aversive stimulation. Apparatus according to the present invention is capable of delivering any rate, but it is preferred to use three different rates of stimulation, low (about 10 bursts per second), medium (about 32 bursts per second) and high (about 56 bursts per second).
The intensity of stimulus delivered to the animal corresponds to the magnitude of the stimulus. In other words, and with respect to an electric shock type of stimulus, the intensity is directly related to the voltage of the shock delivered to the animal. Again, the apparatus of the present invention is capable of delivering virtually any intensity of stimulus, but three settings of electric shock are preferred, low (about 2000 volts), medium (about 3500 volts) and high (about 5000 volts).
Moreover, whatever the type, rate or intensity of aversive stimulus delivered, apparatus according to the invention is capable of arresting or interrupting the delivery of the stimulus whenever the receiver detects that an incoming signal is not a signal characteristic of the coded transmission signal. In particular, preferred apparatus disables delivery of the aversive stimulus after the first stimulatory burst whenever the incoming signal has a duration longer than a set maximum burst duration. Because most interfering radio frequency signals that are commonly encountered in the domestic setting are effectively continuous-wave, aversive stimulation (beyond the initial beep or shock) resulting from the animal's proximity to sources other than the boundary wire is thereby avoided.
FIG. 2 illustrates a coded radio signal that can be generated by the transmitter circuitry illustrated in FIG. 3, described in detail below. FIG. 2 shows, on a time line running from left to right, two successive bursts of pulses received at the receiver antenna above the threshold when the transmitter is set in an audible-plus-shock mode (bursts 202, 204) and in an audible-only mode (bursts 206, 208). Bursts 202 and 206 may be the initial bursts received above threshold; that is, they may be the first bursts received as the animal crosses into the avoidance zone, and further bursts above threshold beyond those shown here will be received until the animal leaves the avoidance zone and the signal falls below the threshold.
Each burst is an envelope of pulses having a period of about 122 μsec (in the circuitry shown in FIG. 3 the frequency is slightly higher than 8 kHz, as the oscillator divides a standard watch crystal oscillation (about 32.768 kHz) by four). In the embodiment shown, bursts 206, 208 have a length of about 7 msec in the audible-only mode; and bursts 202, 204 have a length of about 9 msec in the audible-plus-shock mode.
The burst frequency (which is directly related to the rate of stimulus delivery) may be set to send the bursts at intervals of about 100 msec (in the "slow" repetition rate setting), or about 31 msec (in the "medium" repetition rate setting), or about 18 msec (in the "fast" repetition rate setting). As the receiver unit detects the initiation of an incoming signal above threshold, the receiver unit circuitry causes an audible beep to be produced by the loudspeaker; thereafter, in the audible-only mode, the coded burst ceases at a burst length of about 7 msec, and no shock stimulation is delivered. After the repetition rate interval has passed (100 msec, 31 msec, or 18 msec), if the animal has not yet escaped the avoidance zone, a subsequent coded burst will be detected and the receiver circuitry will cause another audible beep. The receiver will in this way continue to deliver a series of audible beeps until the animal leaves the avoidance zone and the received signal falls below threshold, and then the stimulation will cease.
In the audible-plus-shock mode, each coded burst continues for about 9 msec, and the receiver responds to such longer bursts by delivering a shock to the animal following each audible beep. In one embodiment, the delivery of the shock will occur at every other coded burst (or 200 msec, 61 msec, or 36 msec (depending on the repetition rate setting)) until the animal leaves the avoidance zone.
If, on the other hand, a signal is received above threshold that substantially exceeds the audible-plus-shock mode burst length (as may occur when the animal approaches close enough to an interfering source that generates an effectively continuous-wave signal), an initial audible beep will be delivered as the signal first detected, followed (if the transmitter is set in audible-plus-shock mode) by an initial shock as the signal exceeds a duration of about 8 msec (initially seen by the receiver as an audible-plus-shock mode burst); but thereafter the receiver will recognize that the signal duration exceeds the maximum coded burst length (9 msec), and the circuitry will disable the stimulus delivery so that no further audible beep (or audible beep followed by shock) is delivered to the animal. Then, when the animal moves sufficiently far away from the interfering source that the signal falls below threshold, the system is reset, again enabled and ready to detect an incoming signal above threshold.
Illustrative circuitry that produces such stimulation regimes is described in further detail below, with reference to FIGS. 3-5B.
Transmitter Circuitry
Generally, the transmitter circuits send a coded AM signal through the boundary wire 302, generating a corresponding coded AM radio frequency field near the boundary wire. In preferred embodiments, the signal consists of a series of bursts of pulses; the rate of repetition of the bursts and the frequency of the pulses in the bursts (i.e. the frequency of the transmitted radio signal) and the length of the bursts can be selected, and the receiver delivers an aversive stimulus to the animal whose rate (frequency of stimulation) is related to the burst repetition rate and whose type (auditory or shock) is related to the burst length. The signal that is transmitted by the transmitter through the boundary wire 302 corresponds to the bursts of pulses (202 and 204, or 206 and 208) shown in FIG. 2.
Referring now to the block diagram of FIG. 3, the transmitter includes boundary wire 302, to be installed around the perimeter of the space within which the animal is to be confined, that acts as a transmitting antenna which is driven by circuitry that sends a coded signal through the wire. The transmitter circuitry includes an oscillator 304, burst control circuitry 306 controlled by burst repetition rate selector 308 (shown with three settings, 10 bursts per second ("bps"), 32 bps and 56 bps) and burst length selector 310 (as described above, may be either 7 msec for audible-only or 9 msec for audible-plus-shock); and field strength (wire current) adjustment means, indicated at 312.
Circuitry for generating the coded radio signal is known in the animal training industry. A detailed example of such circuitry is contained in U.S. Pat. No. 5,353,744 to Custer (see particularly FIGS. 5A, 5B and 5C and related text), which is incorporated herein by reference.
Receiver Circuitry
Generally, the receiver unit receives two inputs, one from the magnetically actuated switch and the other from the transmitter. The receiver unit includes receiver circuitry which detects and processes the commands provided by the magnetic switch and the radio signal.
Shown in the block diagram of FIG. 4 and the detailed schematic of FIGS. 5A and 5B, is the circuitry contained within the receiver unit housing. The circuitry includes a power supply 430, a controller 400 and a transducer 440. Operation of the receiver unit is governed by the controller 400 which executes instructions defining the order and conditions under which the receiver unit circuitry activates components of the receiver unit. The controller 400 is connected to and operates the transducer 440 for applying stimulus to the animal when the animal enters the avoidance zone created by the radio signal broadcast from the boundary wire. The controller 400 includes a processor 402 and instructions may be stored in processor 402 or in a separate memory device (not shown). The power supply 430 contained within the receiver unit provides power to the controller and to the transducer 440 for delivery of the stimulus to the animal.
The receiver unit circuitry receives input from a switch assembly 420 and a receiver 410, each of which delivers commands to the controller 400.
The receiver 410 includes three mutually orthogonal antennae L1, L2 and L3, each arranged within the receiver unit along an x, y and z-axis. The antennae are connected to the controller 400 which processes the signals received by the antennae. The controller 400 includes a selector switch 412 to selectively and individually activate each of the three antennae L1, L2 and L3. The controller 400 further includes a tuned circuit such as a resonant amplifier or filter 404 whereby the receiver 410 is tuned to the desired transmitter frequency (preferably the frequency of the coded radio signal).
An amplifier and comparator 406 is included in the controller to receive the signal, if any, from the filter 404. If the strength of the signal from the filter 404 is greater than a predetermined threshold, the amplifier and comparator 406 provide a conditioned signal 6 to the processor 402. When the processor 402 detects the signal from the amplifier and comparator 406, the signal is tested to determine whether the signal is the coded radio signal from the transmitter.
One source of commands to the controller 400 is the switch assembly 420 which includes magnetically actuated switch SW1. Preferably, the switch SW1 is oriented near a side of the housing to readily permit actuation by the magnet located outside the housing. As described above, a user actuates the magnetically actuated switch SW1 by placing the magnet 132 within a zone of actuation of the switch. The controller 400 is connected to the switch SW1 such that when the switch is actuated it delivers a signal 7 to the processor 402. The processor includes a clock circuit which measures the length of time that the switch SW1 is actuated by a user. The processor 402 interprets the command from the switch based upon the length of time that the switch SW1 is actuated. Thus, the switch SW1 delivers a first command when the switch is activated for a first length of time, a second command when the switch is activated for a second length of time and so forth. The commands delivered by the switch to the processor 402 may include the type, rate and/or intensity of stimulus to be delivered by transducer 440 to the animal. Furthermore, the processor may include on/off circuitry (not shown) which is controllable by a command from the switch. In a preferred embodiment, switch SW1 delivers a signal 7 to processor 402 and the signal 7 is interpreted as a command by the controller 400 to set the intensity of stimulus to one of three voltage settings low (about 2000 volts), medium (about 3500 volts) and high (about 5000 volts).
The other input to the receiver unit circuitry is the receiver 410 which receives the radio signal from the boundary wire. In a preferred embodiment, the received and processed signal 6 includes two commands, namely the length of each burst (indicating the type of stimulus, e.g., audio-only or audio-plus-shock) and the rate of the burst transmission (indicating the rate of stimulus, e.g. low shock rate or high shock rate).
In preferred embodiments the processor 402 is capable at any given time of delivering any of a variety of stimulus types, in any range of rates and at any level of intensity. Commands to set these parameters may be from either the switch SW1 or the receiver 410 or a combination thereof.
The signal amplitude from the boundary wire determines whether the controller 400 responds to the signal by delivering an aversive stimulus to the animal. The amplitude of the receiver signal depends upon the strength of the current in the boundary wire and the distance between the boundary wire and the receiver 410; for a given boundary wire current value, if the amplitude is less than the set threshold amount, the amplifier and comparator 406 will prevent the processor 402 from delivering any stimulus to the animal.
The transducer 440 includes a transformer T1 and a speaker SP1. The transformer T1 preferably has primary to secondary winding ratio of 1:100. The secondary side of the transformer delivers the shock to the animal via shock contacts SC1, SC2. The speaker SP1 is a piezoelectric speaker connected to speaker driver 409 that delivers both the audio-type stimulus to the animal and the "beeps" to the user to indicate the command given at the switch. More than one speaker may be used to provide stimulus noises to the animal and/or "beeps" to the user.
A shock driver 408 is connected between the processor 402 and the transformer T1. In this embodiment, the shock driver 408 receives a rate signal and an intensity signal 8 from the processor 402. The shock driver delivers current and voltage from the power supply 430 (which includes a capacitor) to the transformer T1 based upon the rate signal and the intensity signal 8.
The detailed schematic of FIGS. 5A and 5B shows the receiver unit circuitry including controller 400, receiver 410, switch assembly 420, power supply 430 and transducer 440. Particular portions of the receiver unit circuitry will be pointed out as follows.
The amplifier and comparator 406 includes a variable resistor RV1 which can be set at the end of the manufacturing process to ensure that each receiver unit will have approximately the same threshold sensitivity. RV1 is set to control the reference voltage input to comparator U1.
The switch assembly 420 is connected to the processor 402 and includes the magnetically actuated switch SW1, preferably a reed switch (e.g.,.5"-1.5" in length, with an actuation force of between 10-25 and, preferably, 15 ampere-turns) of the type commercially available in the marketplace, e.g., from the Hamlin Corporation, in series with R8 which is connected to voltage VDD2. When the switch SW1 is actuated, a signal is transmitted to the processor. In this example, the processor interprets the time period of the signal as a command for delivering either a low, medium or high shock intensity to the animal. Of course it should be readily appreciated that the switch SW1 could provide other commands by other methods to the processor. For instance, a command could be provided by repetitively moving the magnet in and out of the actuation range of the switch.
The processor 402 delivers five signals to the shock driver 408 indicated at 1, 2, 3, 4 and 5. Signals 1, 2 and 3 are low, medium and high shock signals, respectively, each of which initiates a correspondingly low, medium or high shock intensity at the shock driver 408 when delivered by processor 402. The command for the rate at which the shock is delivered is contained in signal 4. Signal 5 is an audio signal which is provided to both the shock driver 408 and the speaker driver 409 to control speaker SP1 output. The shock driver 408 can also deliver an audio signal to the speaker driver to provide the near simultaneous audible-plus-shock stimulus to the animal.
The remaining portions of the receiver unit circuitry include a supply isolation check valve 450 that isolates the power supply 430 from most of the circuitry in the receiver unit. Also included is a voltage reference circuit 460 which provides a reference voltage V/2 to other components in the receiver unit circuitry. A charge pump 470 converts the 3.6 volt power supply to about a 6.5 voltage source for the shock driver 408 and the speaker driver 409.
It will be apparent to those skilled in the art that a controller according to the present invention may have any of a number of different configurations. For example, the controller could be the processor alone which interprets commands from the switch and/or the receiver and then supplies signals to the transducer for delivery of stimulus based upon such commands. Also, the controller may include any or none of the remaining circuitry described above. By way of example, the shock driver could be included as part of the transducer or the antenna selector switch could be removed entirely from the apparatus.
Receiver Circuitry Flow Diagram
FIG. 6 depicts a flow diagram of certain procedures executed by the controller and related circuitry of FIGS. 5A and 5B. These procedures comprise software code contained within the controller and/or a connected memory device. Those skilled in the art, of course, will recognize that countless variations of the procedures described below are possible.
The controller includes a real time clock counter ("RTCC"). The controller increments the RTCC each time the controller receives signal 6 (a "pulse") from the comparator 406 and each pulse indicates that the receiver 410 has detected a sufficiently strong signal at the desired frequency (see FIG. 4). The RTCC is clocked at approximately 8.192 kHz (32.768 kHz divided by four), the same as the transmitter. The controller includes a programmable prescaler value. The prescaler functions as a divisor; i.e., if the prescaler is set to 1:8, the controller needs to "see" 8 pulses before RTCC is incremented by one.
With reference to FIG. 6, block 601 begins the reset mode of the controller with a time delay. The reset mode occurs when the receiver unit is first powered. The reset mode emits four beeps at 602 to indicate to the user that the receiver unit is on and powered. The reset mode initializes I/O and initializes registers (including RTCC) and sets the prescaler to 1:8 at reference numeral 503.
At block 604, the controller looks for the presence of the magnet (described above) by checking actuation of switch SW1 (again, see FIG. 4). If the magnet is not present, the controller proceeds with a default, medium voltage intensity setting and moves to the listen mode beginning at 611. If, however, the magnet is detected, the controller is set to the high voltage setting and the controller emits three beeps at 605; magnet detection is again checked at 606. If the magnet is again detected, the controller is set to the low voltage setting and the controller emits one beep. The controller iterates through this loop (steps 605, 606 and 607), changing from low to medium to high voltage (and emitting related beeps), until the magnet is not detected by the controller.
Once the magnet is not detected at 606, the controller saves the voltage setting at 608 and enters the zeroing mode at 609 which clears the RTCC. The controller then enters to the listen mode beginning at 611.
The listen mode begins with a time delay at 611. At 612 the RTCC is checked to see if it is empty. If it is empty, then the coded radio signal was not detected by the receiver unit. The listen mode loops iteratively checking the RTCC for a value greater than 0. After a certain iteration time, at 613 the controller turns to a different one of the three mutually orthogonal antennas L1, L2, L3 (see FIG. 4) and again checks for magnet detection at 615. The magnet detection routine proceeds as described above.
If, at 612, the RTCC is not empty then the burst discrimination mode begins at 621. The burst discrimination mode verifies that the burst of pulses has the correct frequency and the correct length. The discrimination mode also determines whether the burst of pulses length corresponds to the audio-only or the audio-plus-shock stimulus.
At 621 the controller waits an period of time (preferably about 977 μsec) and at 622 the RTCC is checked to see if it has been incremented to "2". Steps 623 and 624 similarly wait and then check RTCC for the value "3". If these are the RTCC values, then the controller concludes that the pulses are occurring at the correct frequency, and proceeds to determine the length of the burst.
At 625 the controller repetitively checks to see if the RTCC has changed. If so, a pulse has been received (and thus the burst is continuing). Step 625a shows a blow-up of each 625 step. Upon eight consecutive 625 steps, the controller registers that the burst is greater than the "audible-only" burst length and sets a flag to "audible-plus-shock" at 626. If the RTCC is incremented four more consecutive times after the flag is set, then the burst is too long and the controller recognizes that the signal is not the desired signal and the system enters the zero mode at 609.
If the RTCC count does not change at any one of the 625 blocks, the controller enters the quiet-check mode at 631. This mode looks for the expected quiet time in the signal. If the expected quiet time is not present, no stimulus is delivered, the flags and RTCC are cleared beginning at 641, and the listening mode is reentered at 611.
At block 651 the controller looks to see if the next burst has started. If so, the controller enters the stimulus delivery mode at 661 and checks the flag to determine whether to deliver an audible-only (at 662) or and audible-plus-shock (at 663) stimulus. Thus, in this embodiment, the controller delivers the stimulus after every other detected burst.
After delivering the stimulus, the controller enters the wait-for mode at 671 and waits until the current burst of pulses is over before clearing the registers beginning at 681, and then returns to the listen mode at 611.
The flow diagram in FIG. 6 further provides for a warning zone before the avoidance zone. Such a warning zone extends an additional five to ten feet from the avoidance zone. When the animal enters the avoidance zone, only an auditory signal is delivered. If the animal continues beyond the warning zone, however, and proceeds into the avoidance zone, a shock is delivered. This is accomplished by decreasing the threshold sensitivity of the controller after initial detection of the radio signal. The sensitivity is decreased by some set amount, preferably about 5-20%, and more preferably about 10%.
Implementation of the warning zone is illustrated in FIG. 6 at block 691. Block 691 reduces the gain of the signal at the comparator 406 (see FIG. 4; see also R4 in FIG. 5A). If pulses are no longer detected (RTCC doesn't change) after the gain is reduced, only an audible stimulus will be delivered because the animal is in the warning zone. If pulses are still detected after the gain is reduced at 691, and provided that the audible-plus-shock burst length is detected, then an audible-plus-shock stimulus will be delivered because the animal is in the avoidance zone. The gain is restored to the original amount before reentering the listen mode.
Protection logic is provided to guard against over-stimulating the animal. After a certain number of shocks (preferably between 100 and 200 shocks), shock delivery is disabled until the signal is undetected for a given period of time (not shown). Thus, if the animal becomes trapped in the avoidance zone, the animal will not be over-stimulated with shocks (and instead only an audible signal is emitted which may be heard by the trainer who can free the animal). The logic in the controller further includes a routine to provide the animal with a shock after a certain number of consecutive audible-only stimuli. Thus, if the animal becomes calloused to the audible-only stimulus a shock may provide sufficient incentive to leave the avoidance and/or warning zone. Again, the routine to provide this shock stops shock delivery after a certain number of shocks.
Power Supply
The receiver unit, including the controller and the shock driver, is powered by the power supply, preferably a long-life battery pack. In one embodiment the power supply is one 3.6V lithium battery, though other power supplies may be used instead. Preferably, the battery life in a no signal environment is as long as the greater part of two year's time; a lithium battery has a life in this system of approximately 24 months in a no signal environment, an approximately 25 μAmp drain.
If the receiver unit is in a field, whether produced by the system transmitter or by an interfering source, the battery drain increases; however, it is desirable to restrict the increase in current to as low a value as practical especially in an interfering field.
Preferably the receiver is electronically disabled when an interfering signal is detected, so that current drain is diminished while the animal is in an interfering field. When the animal carries the receiver beyond the detectable range of the interfering signal, it becomes re-enabled and resumes operation.
Avoidance Zone Test
In preferred embodiments, a continuity tester such as a test light is provided for testing the receiver's capacity to deliver an adequate shock stimulus. The test light 133 is provided on the actuator 130 as shown in FIG. 1B. The user holds contact points on the actuator on the contact posts, and then carries the receiver unit 120 into the avoidance zone. When the receiver picks up the signal from the boundary wire, the audible warning sounds at the receiver loudspeaker SP1 and the test light 133 lights.
The system can be tested after installation and before use as follows. The power switch is turned to "on", whereupon the red power indicator light and the green loop indicator light on the transmitter enclosure will come on. The radio signal can be tested by holding the test light pressed across the electrodes on the receiver and carrying the receiver towards the boundary wire at numerous places along the boundary.
Other Embodiments
Numerous other embodiments are within the following claims.
For example, the stimulation regime can be varied. The regime described above, includes two types (audible-only and audible-plus shock), three rates (low, medium and high) and three intensities (low, medium and high) of stimulus. Other combinations can be used and different types, rates and/or intensities of stimulus may be delivered. Alternative stimulation types include, a release of a rapidly dispersing temporarily irritating substance such as, for example, ammonia, as a gas or aerosol.
Numerous other configurations of the magnetically actuated switch may be utilized. For example, more than one switch can used to deliver commands to the controller. A first switch could vary the intensity of stimulus and a second switch could vary the rate of stimulus delivered to the animal. Each switch could be connected to the speaker to indicate the command that was delivered, and the speaker may produce different sounds corresponding to the commands delivered by the two switches. The switch may provide an on/off command to the receiver unit which prevents the receiver unit from delivering the stimulus. Additionally, a light or LED in the housing or the actuator could indicate the various commands input at the switch.
Other configurations may be used for the coded transmitter signal. The pulse rate can be other than the approximately 8 kHz rate described in the examples. Burst repetition rates (and, hence, the rate of stimulus) other than those illustrated can be used, and others may prove more effective for different breeds and types of animals; rates as low as about 3 bursts per second and as high as about 300 bursts per second have been shown to be effective. A different range of selectable repetition rates can be provided.
The intensity of each shock in the stimulus series can be different from that shown, although shocks at approximately 2000, 3500 or 5000 volts, delivering approximately 5 mA, appear to be effective for canines; currents in the range between about 1 mA and about 30 mA also appear effective. The shock energy and shock pulse shape can differ, particularly for different types and breeds of animal. Burst lengths other than those illustrated can be used to encode the audible-plus-shock mode and the audible-only mode, and maximum length for non-pulse (interfering, effectively continuous-wave) signals.
It is possible that an animal may under some circumstances (for example, illness, or imperfect training) respond to the aversive shock stimulus by assuming a submissive posture, and remaining within the avoidance zone; or the animal may become trapped in the avoidance zone. Because the illustrative embodiment provides for continuous stimulation for as long as the animal remains within the avoidance zone, the animal under these circumstances will not leave the avoidance zone, and if unattended in these circumstances will be overstimulated. The stimulation regime can be altered to avoid such overstimulation by automatically switching from the audible-plus-shock mode to an audible mode (or turn all stimulation off) after some period of continuous electrical shock stimulation, thereby allowing the animal relief from long term repeated shock or other aversive stimulus.
It should be understood that the preceding is merely a detailed description of certain preferred embodiments. It therefore should be apparent to those skilled in the art that various modifications and equivalents can be made without departing from the spirit or scope of the invention. | An apparatus and method for training an animal and confining the animal to a defined area includes a magnetically actuated switch. The apparatus further includes a housing removably attached to the animal and a transducer mounted to the housing for delivering a stimulus to the animal. The magnetically actuated switch is disposed within the housing and is coupled to the transducer. The magnetically actuated switch is used for controlling at least one of a type of stimulus delivered by the transducer to the animal, a rate of stimulus delivered by the transducer to the animal, and an intensity of stimulus delivered by the transducer to the animal. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional patent application entitled “Swimmer Safety Tags”, Ser. No. 60/951,243 filed on Jul. 23, 2007. Said provisional application is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention is in the field of swimmer safety.
COPYRIGHT AND TRADEMARK NOTICE
A portion of the disclosure of this patent document contains material to which a claim for copyright is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but reserves all other copyright rights whatsoever.
The word “WAHOOO” and fish logo as shown, inter alia, as item 1116 in FIG. 11A are trademarks of Aquatic Safety Concepts LLC.
BACKGROUND
Drowning is the second leading cause of accidental death in children in the United States. Adults are present in ninety percent of those incidents, intending to monitor the children to prevent drowning, yet the children all too often drown in silence, as their instantaneous peril readily escapes notice. Adult drownings in supervised settings are sadly common for the same reason.
SUMMARY OF THE INVENTION
The Summary of the Invention is provided as a guide to understanding the invention. It does not necessarily describe the most generic embodiment of the invention or all species of the invention disclosed herein.
The systems and methods of the present invention are designed to assist supervisory personnel to monitor people to reduce the risk of dangerous submersions. The invention advances the art by providing effective and commercially economical means to automate prompt notice of supervisory personnel of a person in potential distress.
The systems and methods of the present invention comprise equipping each person to be monitored in an aquatic environment with an electronic Tag worn on the body at a position from which immersion of the nose and mouth can be inferred, together with means for timing the immersion of the Tag in water for one or more periods of time associated with possible risk of drowning, and means for communicating between the Tag and electronic monitoring equipment, including alarms, and devices for system control and communications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of the entrance to a pool area where swimmers place Swimmer Safety Tags on their persons.
FIG. 2 is a view of swimmers wearing Tags entering the water.
FIG. 3 is a view of swimmers being monitored by a Swim Monitor Unit.
FIG. 4 is a view of a swimmer setting off a Yellow Alert.
FIG. 5 is a view of lifeguard and Control Unit being notified of a Yellow Alert.
FIG. 6 is a view of a swimmer setting off a Red Alarm.
FIG. 7 is a view of a lifeguard responding to a Red Alarm.
FIG. 8 is a view of a lifeguard rescuing a swimmer who triggered a Red Alarm.
FIG. 9 is a view of a pool with exemplary hydrophone placement.
FIG. 10 is a view of a pool with alternative exemplary hydrophone placement.
FIGS. 11A-11D are views of an exemplary Swimmer Safety Tag (“Tag”).
FIG. 12 is an exploded perspective view of a Tag.
FIG. 12 is a top view of an alternative Tag design.
FIGS. 14A-14D are cross sectional views of an exemplary means for packaging and dispensing Tags.
FIG. 15 is a perspective view of an exemplary means for packaging Tags for retail sale.
FIG. 16 is a top view of an alternative exemplary means for packaging Tags for retail sale.
FIG. 17 illustrates a method for refurbishing Tags.
FIG. 18 illustrates a means for mounting Tags on a swimmer's head using an elastic band.
FIG. 19 illustrates a means for mounting Tags on a swimmer's head using adhesive “wings”.
FIG. 20 is an illustration of an alternative means for determining how long a swimmer's head has been below water using the blockage of radio transmissions.
FIGS. 21A-21C are illustrations of a hip mounted Tag.
FIG. 22 illustrates the functionality of a hip mounted Tag.
FIGS. 23A-23C illustrate an exemplary annunciation unit portion of a Swim Monitor Unit.
FIG. 24 illustrates means for recharging the battery of an annunciation unit and alternative means for storing a connecting cable.
FIGS. 25A-25B illustrate an exemplary hydrophone unit portion of a Swim Monitor Unit.
FIG. 26 illustrates alternative positioning of an annunciation unit.
FIG. 27 illustrates an exemplary Control Unit.
FIG. 28 illustrates means for an annunciation unit to communicate with supervisory units as well as the Control Unit.
FIG. 29 is an illustration of a neck mounted Tag.
FIG. 30 is an illustration of an ear mounted Tag.
FIG. 31 is an illustration of a neck mounted Tag.
FIG. 32 is an illustration of an alternative ear mounted Tag.
DETAILED DESCRIPTION
The following detailed description discloses various embodiments and features of the invention. These embodiments and features are meant to be exemplary and not limiting.
As used herein, the term “about” means within +/−20% of a given value unless specifically indicated otherwise.
Method for Increasing the Safety of Swimmers
FIGS. 1 to 8 illustrate an exemplary method for increasing the safety of swimmers as applied to a pool area. Similar methods can be applied to open water swimming areas, such a lake or ocean.
Referring to FIG. 1 , a pool area 100 is surrounded by a perimeter fence 120 with an opening 122 therein. Swimmers, such as children 102 , or adults 108 , pass through said opening on their way to the pool area. Each swimmer is provided with a Swimmer Safety Tag 104 that is affixed to a position on his or her head. Suitable positions include the forehead 106 or behind an ear. The Tags are provided with an adhesive so that they will remain affixed even in water, but can be removed without undue force or discomfort. Hence said Tags are said to be “removably mountable”. The adhesive used in water-proof bandages is suitable.
The Tags may be stored in a locker 112 . A supervisor 110 may be present to provide assistance with putting a Tag on and/or to make sure that all persons entering the pool area are “Tagged”.
Referring to FIG. 2 , the Tags 202 are electronic devices which will determine, inter alia, how long a person's head has been underwater and hence, by implication, how long both their nose and mouth are underwater. If a person's head has been underwater longer than a predetermined safe period, such as 30 seconds, an alarm will be triggered. Different alarm levels may be set at different time periods. A “Yellow Alert” may be set in the range of 20-30 seconds. A “Red Alarm” may be set in the range of 30-45 seconds. A preferred range for Yellow Alerts is 20 to 25 seconds. This will provide adequate warning to a lifeguard to identify, rescue and administer first aid to a distressed swimmer. A 20-25 second delay to Yellow Alert may be particularly suitable for young children, such as those six years old and under. These children would be less likely swim underwater for 25 seconds as part of their normal play the way older or more skilled children can.
An alternative alarm is simply a Red Alarm that is triggered by a Tag being underwater for 25 seconds or longer.
The Tags are activated when a person's head 204 enters the water 210 . The alarm signal may be an ultrasonic signal transmitted through the water.
Referring to FIG. 3 , the pool water is monitored by one or more Swim Monitor Units (SMU) 302 . A Swim Monitor Unit comprises an annunciation unit 310 , a connector cable 320 and a hydrophone unit 330 . The annunciation unit may comprise a strobe light 312 . They hydrophone unit may be placed near the bottom of the pool.
Referring to FIG. 4 , the hydrophone unit 430 listens for ultrasonic signals from the Tags. If a swimmer's head had been below the water for more than the Yellow Alert period, for example, then that swimmer's Tag gives off the ultrasonic Yellow Alert 402 . The signal is received 404 by the hydrophone unit and is transmitted (e.g. electrically) along the connector cable to the annunciation unit and the annunciation unit takes appropriate action, such as flashing the strobe 412 .
Referring to FIG. 5 , in addition to flashing the strobe, the annunciation unit 502 may also transmit a radio signal 504 to a nearby Supervisory Control Unit 510 . The radio transmission may be at typical frequency bands allocated to alarms, such 433 MHz The Control Unit, in turn, may also take appropriate action, such as flashing its strobe 512 and activating 514 other visual or audio alarms 520 .
Alternatively or in addition, the annunciation unit may communicate 506 an alarm signal directly to a portable reception unit 540 worn by a lifeguard 530 . Communication may be via suitable portable unit communications means, such as digital signals utilizing Bluetooth® technology or Bluetooth® Version 2 technology (collectively “Bluetooth” herein). The portable reception unit may notify the life guard that there is an alert via light, noise and/or vibration 542 .
Upon activation of a Yellow Alert, a lifeguard may take appropriate action, such as to call for a “buddy check” where all swimmers grab their buddy's hand and hold it up. This way the lifeguard can quickly confirm and identify which swimmer is in distress.
Referring to FIG. 6 , if a swimmer's head is underwater for more than the Red Alarm period (e.g. 45 seconds), then the Swimmer Safety Tag may transmit 602 a Red Alarm. The hydrophone will receive the Red Alarm and the annunciation unit and other components of the system may take appropriate action, such as sounding an audio alarm or notifying local emergency medical personnel. The lifeguard, in turn, may take appropriate action, such as clearing the pool of all swimmers and searching for the swimmer in distress.
Referring to FIGS. 7 and 8 , once the swimmer in distress is located, the lifeguard 702 can retrieve the swimmer and apply appropriate first aid if needed. The life guard may also reset the alarm system to the standby state and silence the alarms.
In an alternative embodiment, the Red Alarm automatically resets after a certain period of time. 1 to 2 minutes is an appropriate period of time. The benefit of a Red Alarm automatically resetting after 1 to 2 minutes is that by that time, it is likely that a lifeguard is applying first aid to the distressed swimmer. A continuous alarm would otherwise distract the lifeguard during the administration of first aid when the lifeguard must pay particular attention to, for example, the proper administration of artificial respiration.
System for Increasing the Safety of Swimmers
It will be appreciated by a person of ordinary skill in the art of water safety, that a practical system implementing the methods describe herein must simultaneously meet a number of demanding criteria. These criteria include, but are not limited to:
Acceptably low number of “false positives”. Similar to the “Boy who Cried Wolf”, If the system constantly indicates that a swimmer is in distress when, in fact, that isn't the case, then personnel will learn to ignore the system and thus not respond appropriately when a swimmer really is in peril. Very low number of false negatives. The system must be very reliable in terms of identifying swimmers that really are in distress. Acceptable to users. The system, and in particular the Swimmer Safety Tags, must be acceptable to the users. Otherwise they will resist using them, their enjoyment will be degraded and their safety compromised. Similarly, the supervisory personnel, such as lifeguards, must find the system easy to use and understand. Cost effective. The cost of the system must be commensurate with the benefits provided, competitive with alternatives, and encourage its use. Safe to use. The system should not introduce new safety hazards that negate the overall benefit provided to the users. Similarly, the system should be environmentally compatible.
FIGS. 9 and 10 illustrate an embodiment of the present invention that has improved reliability in terms of picking up a swimmer's ultrasonic distress signal (i.e. lower false negatives). It is common for splashing, bubbles and clusters of swimmers 910 to exist from time to time in a pool. These effects can collectively block a distress signal 912 from reaching a given hydrophone 902 . With at least a second hydrophone 904 mounted in the pool, the probability of a distress signal 914 reaching at least one unit is significantly increased. Suitable positioning of four hydrophones 1002 is illustrated in FIG. 10 .
Referring back to FIG. 9 , in addition to normal duties, a lifeguard 920 may be responsible for observing all swimmers and insisting that any swimmer 930 without a Tag either get a Tag or leave the pool area. This task can be facilitated by providing Tags with a light so that they can be more easily seen.
FIGS. 11A-11 D illustrate embodiments of the Tags that have improved user acceptability and reduced numbers of false positives. FIG. 11A illustrates a top perspective view of a Tag; FIG. 11B illustrates a bottom perspective view of a Tag; FIG. 11C illustrates the size scale of a Tag; and FIG. 11D illustrates the mounting of a Tag on a swimmer.
Referring to FIGS. 11A and 11C , a Tag 1100 may have a diameter 1112 in the range of 5 to 30 mm, and a thickness 1114 in the range of 1 to 10 mm. A preferred range for diameters is 10 to 20 mm. A preferred range of thicknesses is 3 to 5 mm. These dimensions give the Tag a size, shape and heft (i.e. perceived weight in the hand) comparable to that of common coins (e.g. US pennies, dimes, nickels and quarters 1130 ). An exemplary Tag, for example, would have a diameter of 20 mm, a thickness of 5 mm and a weight of 3 gm in air. The maximum suitable weight would be 10 gm in air. Thus mounting a Tag on a swimmer's head ( FIG. 11D ) would not be perceived as an undue burden. Furthermore, Tags could be effectively manipulated by persons of ordinary physical skill and dexterity. Supervisory personnel could place Tags on persons with physical handicaps.
The top surface of a Tag could be provided with a logo 1116 or other suitable indicia such as a decoration (e.g. flower) or affinity brand (e.g. sports logo). A light source, such as an LED 1118 , can be provided for easy identification as well as providing an indication that the Tag is functioning properly. The LED may blink at a frequency of no less than once every 10 seconds. This will help conserve battery life. The Tag may also be programmed to flash the LED or multiple LEDs very brightly or frequently in the event of a Yellow or Red Alarm. This will help a lifeguard identify which swimmer is in distress. The LEDs may also change color in response to a Yellow or Red Alarm.
Electrical contacts 1110 may be provided on opposite sides of a Tag to sense immersion in water. The water acts as a conductor and closes a circuit between the contacts when the Tag is immersed. An internal timer then initiates. If the Tag is removed from water, the circuit is open and the timer stops and resets.
Referring to FIG. 11B , an adhesive 1112 may be provided on the bottom of a Tag. The adhesive should be medical grade, hypo-allergenic and non-irritating. It should be able to adhere the Tag to a swimmer's head for not less than 10 hours.
A sensor 1114 may also be provided on the bottom of the Tag to confirm that the Tag is mounted on a person. The sensor may be an optical switch that opens when illuminated. Thus when the Tag is mounted on a person, the switch is dark and closed and the internal circuitry functions normally. If the Tag is removed or falls off, then the switch is illuminated and opens. The Tag may either then stop functioning, or may issue a signal indicating that it is no longer mounted on a person. If the Tag is made more dense than water, it will sink and can be retrieved by a vacuum. If a Tag is less dense than water, it will float and can be retrieved by skimming.
An alternative sensor is one that optically measures oxygen in the blood directly below the Tag. This can be used to confirm mounting on the person as well as provide an alternative measure of the distress of a person. If the oxygen is low, then the person is in distress. Similarly, the pulse can be measured and interpreted accordingly.
Another alternative sensor comprises a pair of electrical contacts 1117 on the bottom of a Tag. They are normally dry as long as the Tag is mounted on a person. If the Tag falls off in the water, however, then the contacts are connected electrically through the conductivity of the water and the Tag has an indication that it is no longer mounted on a person.
FIG. 12 illustrates an exploded perspective view of the Tag of FIGS. 11A-11D . The Tag 1200 comprises a top encapsulating layer 1210 , a battery 1220 , electronic circuitry 1230 , a piezoelectric transducer 1240 , a bottom encapsulating layer 1250 and an adhesive layer 1260 .
The top encapsulating layer may be a waterproof, two-part epoxy designed to protect electronics that are submerged in water. The Tag should be water proof to a depth of 300 meters. The epoxy may be cast over the electronics and underneath and allowed to harden. Alternatively, the top encapsulating layer may be a cover that is bonded to the bottom encapsulating layer.
Openings 1214 may be milled in the top encapsulating layer after it hardens to expose electrical contacts 1232 on the circuit board of the electronic circuitry. This would allow the circuit between the electrical contacts to close when the Tag was immersed in water and thus begin a timer. Alternatively, a conductor 1212 may pass through the top of the encapsulating layer as one contact, and one or more opening 1252 may be milled in the bottom encapsulating layer to expose the piezoelectric layer. The piezoelectric layer, therefore, acts as the second contact. The circuit between the top conductor and piezoelectric layer then is closed when the Tag is immersed in water. Four openings 1252 may be milled at four compass points to reduce the chance that a swimmer's skin blocks all of the openings to the piezoelectric contact.
Both the electrical circuit components and programming logic are chosen to give reliable performance with minimized power draw. This improves the reliability and lifetime of the Tag. The Tag may have an operating lifetime of at least 30 days, and a storage shelf-life of at least 2 years. The Tag may further comprise an activation means, such as a pull tab, which turns the Tag on.
The electrical circuit comprises a micro processor 1234 , amplifier 1238 and optional LED 1239 .
A suitable micro processor is a PIC10F220, 6 pin, 8 bit flash microcontroller by Microchip Technology Inc. Said microprocessor is more fully described in PIC10F220/22 Data Sheet, publication number DS41270A by Microchip Technology Inc, 2005. Said publication is incorporated herein by reference. Other microprocessors with similar performance, power draws, cost and size characteristics may also be suitable.
The microprocessor may be programmed to have different outputs in different states. The states and outputs are presented in Table 1.
TABLE 1
Duty Cycle
(Duration per 1.1 or
State
Output
2.2 second cycles)
Resting
71.4 kHz square wave
15 ms
(ultrasonic)
Yellow Alert
71.4 kHz square wave
300 ms
Red Alarm
71.4 kHz square wave
700 ms
Low battery (<20%
1.2 kHz square wave
750 ms
remaining power) or
(audible)
detached Tag
The output of the microprocessor is amplified by the amplifier and then used to drive the piezoelectric layer to give the ultrasonic or audible signal. An inductor may be placed in series with the piezoelectric layer. The inductance is selected based on the effective capacitance of the piezoelectric layer to give a resonance frequency of the circuit about that of the desired ultrasonic frequency. This improves the power efficiency of the circuit.
A suitable piezoelectric layer is a CEB-20D64 piezoelectric diaphragm made by CUI Inc. The technical specifications of said diaphragm are described more fully in the CUI spec sheet for the CEB-20D64 dated Jul. 28, 2006. Said spec sheet is incorporated herein by reference. This diaphragm is disk shaped and has a suitable diameter (20 mm), material of construction (brass) and cost ($0.75 ea) for this application. It is surprising that it provides adequate ultrasonic emissions, however, given that the mechanical resonance frequency is 6.5+/−0.5 KHz.
The resting state is the normal default state of the system. The microprocessor is normally in a very low current “sleep” mode. Every 1.1 or 2.2 seconds (selectable by the user), it “wakes up” and determines the state that it is in. If the clock timer indicating submersion is less than the Yellow Alert level (e.g. less than 30 seconds) then it gives a 15 ms ultrasonic “ping” at 71.4 kHz. Ultrasonic frequencies in the range of 30 kHz to 100 kHz may also be used. At lower frequencies, naturally occurring ambient noise causes interferences. At higher frequencies, more expensive and different shaped (e.g. cylindrical) ultrasonic transducers must be used. 71.4 kHz was selected in this particular application since it represents an even multiple of the clock speed of the microprocessor. Thus, generating the square wave comprises counting clock cycles. It also gives a wavelength of the ultrasonic transmissions in water of about 2 cm. This wavelength is suitable in pools. Longer wavelengths, such as 10 cm, can lead to “dead spots” in the pool where the emitted ultrasonic waves destructively interfere with each other might not be heard by a hydrophone if said hydrophone were located in said dead spot.
The ping can be received by the hydrophones and might serve, for example, for counting the number of swimmers in the water in any given time. Ideally the ping should be as short as possible to minimize resting state power draw on the battery. Ping durations in the range of 5 ms to 30 ms are acceptable. The ping should have a large enough amplitude or power so that it is detectible by a hydrophone no less than 50 meters away.
If the microprocessor wakes up and determines that the submersion timer has exceeded the Yellow Alert level, then it gives a Yellow Alert signal of 300 ms at 71.4 kHz. This is immediately picked up by one or more hydrophones and a Yellow Alert is initiated. The nearest hydrophone to the signal may have an appropriate indication to assist the lifeguard in locating the distressed swimmer. The microprocessor may also simultaneously drive the piezoelectric layer to emit a loud sonic signal. This will help a lifeguard identify which swimmer is in distress.
If the microprocessor determines that the submersion timer has exceeded the Red Alarm level, then a Red Alarm signal of 700 ms is given. The hydrophones then react accordingly.
The relative and absolute length and frequency of the Yellow Alert and Red Alarm signals can be varied so long as they are readily discriminated by the hydrophones. An advantage of selecting a Red Alarm duration that is more than twice the duration of a Yellow Alert signal is that the system can discriminate between two simultaneous Yellow Alerts and a single Red Alarm. An advantage of having a pause between Red Alarm signals is that the system can discriminate between a single Red Alarm signal and multiple Red+Red or Red+Yellow signals. Multiple Red+Red or Red+Yellow signals would indicate that more than one swimmer was at risk.
An advantage of having each tag broadcast a similar signal is that the Yellow Alert or Red Alarm message will get through even if there is significant echoing within the pool.
The system can be designed to provide digital information encoded in the ultrasonic carrier wave. This has the advantage of being able to directly identify which tag is emitting a distress signal.
The low battery and/or detached Tag signal can be initiated when the battery voltage indicates that less than 20% of the battery life is remaining or when a sensor indicating that a Tag is immersed but not attached to a swimmer is indicated. The signal can be an audible 1.2 kHz signal pulsed for 750 ms per cycle. 0.5 to 2.0 kHz are also acceptable. The audible signal has the advantage of making it readily apparent to persons nearby that a Tag has a low battery or is off of a person.
A suitable battery is a CR1616 2, 3V, Lithium Coin Cell battery made by Panasonic. The technical specifications of these batteries are described more fully in the Panasonic Lithium Handbook, August 2005. Said handbook is incorporated herein by reference. The batteries are rechargeable, have a size that is suitable for this application and have a power rating of 50 milliamp hours at 3V when fully charged. A power rating of 25 to 74 milliamp-hours is suitable in this application.
The above described system has a current draw of 2 micro amps when it is in storage. That gives an estimated battery shelf life of about 3 years. The Resting state current draw is 65 micro amps. That corresponds to a 30 day life of submersions. There is enough power to give a Red Alarm for 16 hours. The low battery signal will last 8 days.
The order of the layers in FIG. 12 can be varied. The battery, for example, can be below the electronic circuit.
FIG. 13 shows a top view of an alternative Tag design 1300 for detecting submersion. The circuitry is sealed within a water tight enclosure 1306 . Electrical contacts 1304 protrude into a porous protective enclosure 1302 . When water penetrates the enclosure, the circuit is closed.
Packaging of Tags
FIGS. 14A-14D illustrate cross sections of a suitable packaging method for the Tags.
Referring to FIG. 14 A, a packaging card 1410 comprises a substrate layer 1412 , and adhesive layer 1414 and a backing layer 1416 . The substrate and backing layers may be made of cardboard. The adhesive layer may be a double stick tape with hypoallergenic, waterproof bandage adhesive. A round opening 1418 is provided to receive a Tag 1400 . The Tag has rounded edges 1401 to facilitate handling. The opening may comprise a protective bumper 1420 . The Tag is pressed onto the exposed adhesive layer 1406 which, in turn, is backed by a disk 1402 . The disk is made of a material that the adhesive does not stick well to.
FIG. 14B shows how the assembly looks for shipping.
FIG. 14C shows how a Tab would be pushed out of the packaging card by an end user.
FIG. 14D shows how the backing disk would be removed leaving behind the adhesive layer 1406 .
The adhesive should stick more strongly to the Tab than it would to a person's skin so that the adhesive is removed from said person's skin when the Tab is removed.
FIG. 15 shows how a packaging card 1506 would be incorporated into a commercial retail package 1500 . Wings 1508 may be attached to the packaging card with appropriate information and indicia printed thereupon. The assembly may be folded 1504 and inserted into a sleeve 1502 .
FIG. 16 illustrates alternative packaging for a single Tag 1604 . The single Tag is packaged in a hinged container 1602 and the hinged container is mounted on a retailing card 1600 .
Refurbishing Tags
The Tags may be recycled. FIG. 17 illustrates a suitable refurbishing process. Used Tags are collected 1702 and shipped 1704 to a refurbishing facility 1706 . The Tags are cleaned, tested 1708 , recharged 1710 , and inspected 1712 . New adhesive 1715 is applied 1714 to the Tags 1713 and the Tags are packaged 1716 , crated 1718 and shipped 1720 to an end user 1722 .
Alternative Tag Technologies
FIG. 18 illustrates an alternative mounting technology for a Tag. The Tag 1802 is provides with an adjustable elastic strap 1804 . The assembly 1800 is then worn around the head of a swimmer.
FIGS. 19A to 19D illustrates an adhesive bandage type of mounting. A Tag 1900 is provided with flexible adhesive wings 1902 . The assembly is then adhered to the head of a swimmer. FIG. 19A shows a top view; FIG. 19B shows a side view; FIG. 19C shows a size comparison with a US quarter; and FIG. 19D shows the Tag mounted on a swimmer's head.
This configuration has the advantage of providing a convenient means for mounting a radio antenna 1904 on a Tag. The antenna facilitates an alternative means for determining how long a person's head has been underwater.
FIG. 20 shows a radio means for determining how long a person's head has been in water. A swimmer 2002 has a Tag mounted on his or her head. The Tag emits a constant or pulsed radio signal 2004 , along with identifying information to a control station 2006 . The control station keeps track of all Tags. When a person goes swimming and their head goes below water, the signal is blocked 2012 by water. The control station determines that a particular Tag is no longer above water and a timer 2008 is started. If the timer reaches a certain threshold, then a Yellow Alert or a Red Alarm may be signaled.
This system is advantageous at beaches where large distances can separate swimmers and where mounting and positioning of sonar based Swim Monitor Units may be difficult.
FIGS. 21A-21C illustrate a hip mounted Tag design 2100 . FIG. 21A shows a top view; FIG. 21B shows a bottom view; and FIG. 21C shows a perspective view with a size comparison to a US quarter 2110 .
This Tag is larger than the coin size sonar based Tag discussed with reference to FIG. 11C . The size may be 6 cm ( 2102 ) by 7 cm ( 2104 ). The maximum dimension may be 10 cm. The corners may be rounded 2106 to avoid snagging on clothes. The larger size facilitates the incorporation of larger indicia 2108 and strobe lights 2112 . Mounting means, such as a safety pin 2114 may be provided to removably attach the Tag to clothes and a pressure sensor 2116 may be provided.
FIG. 22 shows how a hip mounted Tag would work. The Tag 2206 is mounted on a swimmer 2202 . When the swimmer's hips are more than one meter 2204 below the surface of the water, a sensor of depth, such as a water pressure sensor, triggers a timer. If the timer runs for the duration of a Yellow Alert or a Red Alarm, the Tag sends a sonar signal to a Swim Monitor Unit. They system is functional for both tall persons and short persons 2208 .
Skipping ahead to FIG. 29 , FIG. 29 illustrates a Tag 2900 mounted on a necklace 2910 . The Tag comprises a magnetic latch or mechanical latch 2904 to allow it to be easily put on and removed. The Tag may comprise a water emersion sensor and/or a water depth sensor. The Tag may, for example be set to sound an alarm when the depth is more than 30 cm for a given period of time.
FIG. 30 illustrates a Tag 3000 that can be mounted on a swimmer's ear 3020 . The Tag comprises a sensing unit 3002 and a band 3012 . The sensing unit may comprise electrical contacts 3004 for sensing immersion in water and/or a pressure sensor for detecting immersion at depths greater than a predetermined amount, such as 30 cm. The sensing unit may also comprise LEDs 3006 .
The band 3012 may comprise a cushion 3014 as well as a means 3016 to adjust the length.
A similar Tag without the band may also be mounted in the hollow 3022 behind a swimmer's ear by using a moldable waxy mounting compound.
FIG. 31 illustrates a Tag 3100 that is in the form of a stiff but flexible open neck band. The Tag comprises a strap 3102 and pads 3104 . The electronics of the Tag can be built into the strap. Electrical contacts 3106 are built in to each end of the strap. Thus, both sides of a swimmers head must be underwater to start the submersion timer. The strap is stiff enough to hold the band onto a swimmer's head 3110 , but flexible enough to be removed by a person of ordinary strength. The Tag may further comprise one or more LEDs 3108 .
FIG. 32 illustrates a Tag 3200 that is mounted on an ear plug. The electronics 3202 are mounted on an elastomeric (e.g. silicone rubber) ear plug 3204 to form a final assembly 3206 . This is then mounted in a swimmer's ear 3210 . The ear plug may be disposable and the mounting may be mechanical by, for example, a lip (not shown) built into the plug.
Swim Monitor Unit
Referring back to FIG. 23 , a swim monitor unit comprises an annunciation unit, connector cable and hydrophone unit. FIGS. 23A , 23 B and 23 C illustrate a side, top, and bottom view of an exemplary annunciation unit 2300 . Referring to FIG. 23A , the annunciation unit comprises a strobe light 2302 for indicating alarm status, a connector cable 2304 for connecting to the submerged hydrophone, and associated electronics 2306 for amplifying and processing the ultrasonic signals received from the Tags.
Referring to FIG. 23B , the annunciation unit further comprises a removable rechargeable battery 2312 , and an LED 2314 , to indicate that it is working.
Referring to FIG. 23C , the annunciation unit further comprises mounting means 2322 , a locking cover 2324 and indicia 2326 indicating product information.
FIG. 24 illustrates other features of an annunciation unit 2400 . The rechargeable battery 2402 is removable and may be placed in a recharger 2404 to recharge. The connector cable may be stored in a retractable reel 2406 or expandable coil 2408 .
FIGS. 25A-25B illustrate an exemplary hydrophone unit. FIG. 25A shows a perspective top view of the hydrophone unit 2500 ; and FIG. 25B shows a side view of the hydrophone unit.
Referring to FIG. 25B , the hydrophone unit comprises a hydrophone 2512 for receiving ultrasonic signals from Tags; a protective cage 2514 to protect the hydrophone unit from, inter alia, swimmers hands and feet, a retractable coil 2516 for storing excess connector cable, and mounting means, such as suction cups 2518 for adhering the hydrophone unit to the wall of a pool.
Suitable hydrophone units, such as an SUR-1 Submersible Ultrasonic Receiver, may be obtained from Sonotronics Inc. of Tucson Ariz. The SUR-1 is more fully described on web page “SUR-1 Submersible Ultrasonic Receiver”, www.sonotronics.com/html/products/receivers/sur.html. Said web page is incorporated herein by reference.
Suitable hydrophone units may have a bandpass of +/−6 kHz of the designed ultrasonic signal of the Tags. Thus if the Tags are designed to broadcast at about 70 kHz (e.g. 71.4 kHz), then the hydrophone would have a bandpass of 64 to 76 kHz. This relatively narrow bandpass helps filter out background noise.
FIG. 26 illustrates alternative mounting configurations for an annunciation unit. The annunciation unit may be mounted horizontally 2602 on the side of the pool. This has the advantage of having the strobe light entirely out of the water. Alternatively, the annunciation unit may be mounted vertically 2602 on the wall of the pool. This has the advantage of providing strobe light to the occupants of the pool that may be underwater at the time of an alarm. Alternatively, the annunciation unit may be mounted on the deck of the pool 2606 . This has the advantage of being relatively easy to install.
Supervisory Control Unit
FIG. 27 illustrates a face view of an exemplary Supervisory Control Unit 2700 . The control unit comprises a power supply and electronics suitable for receiving signals from annunciation units and transmitting signals to alarms if necessary. The control unit further comprises a locking cover 2702 , indicator LED 2704 , strobe alarm light 2706 , informational screen 2708 and touchpad 2712 for entering data and commands. A US quarter and Tags 2720 are shown to indicate scale.
Portable Reception Units
FIG. 28 illustrates a number of alternative embodiments of portable reception units that may be worn by a lifeguard or other supervisory personnel. These include ear pieces 2826 , bracelets 2828 and necklace tokens 2832 . These designs may be both functional and have a certain aesthetic appeal.
As discussed above, the portable reception units would receive alarms 2824 from annunciation units 2812 after said alarms were received from Tags 2802 worn by swimmers. Communications may be by Bluetooth protocol.
Portable Family Systems
A completely portable embodiment is suitable for families visiting a body of water. It can consist of Tags, one or more portable battery powered SMU units, a battery powered Supervisory Control Unit and/or one or more Portable Reception Units. The Supervisory Control Unit may be configured like a briefcase or “boom box.”
EXAMPLES
Example 1
A 25 meter long by 6 meter wide indoor pool was equipped with a swim monitor unit. The pool had a shallow end 1 meter in depth, and a deep end 3 meters in depth. The swim monitor unit was mounted at the middle of the wall of the deep end. The hydrophone rested on the bottom of the pool at a depth of 3 meters. The annunciation unit rested on the edge of the wall of the pool and communicated with a Supervisory Control Unit by radio transmission. The supervisory control unit was 3 meters from the annunciation unit.
A test swimmer entered the water at the midpoint of the pool and submersed a Tag in the water. The Tag was programmed to emit an ultrasonic Yellow Alert signal at 30 seconds and an ultrasonic Red Alarm signal at 45 seconds. After the Tag had been submersed for 30 seconds, the supervisory control unit sounded a Yellow Alert. The test swimmer then removed the Tag from the water and the Yellow Alert ceased.
The test swimmer then put the Tag in the water again. At 30 seconds, the Yellow Alert sounded. At 45 seconds the Red Alarm sounded. The test swimmer removed the Tag from the water and a supervisory person reset the control unit to silence the Red Alarm.
10 “interference swimmers” then entered the deep end of the pool, clung to the side walls of the pool and kicked the surface of the water vigorously to produce both bubbles and splashes. The interference swimmers were located between the test swimmer and the swim monitor unit. The test swimmer placed the Tag below the water, but at 30 seconds, no Yellow Alert sounded. The interference swimmers then stopped kicking and the Yellow Alert sounded.
A second swim monitor unit was then placed at the midpoint of the wall of the shallow end of the pool behind the test swimmer. The hydrophone was placed on the bottom of the pool at 1 meter depth. The annunciation unit was placed on the wall of the pool. The annunciation unit was about 28 meters from the control unit.
There were no interference swimmers between the test swimmer and the shallow end hydrophone. The interference swimmers then began kicking in the deep end and the test swimmer again placed the Tag below the surface of the water. A Yellow Alert sounded after the Tag had been submersed for 30 seconds.
Example 2
11 swimmers were equipped with Tags placed on their heads. The Tags were 20 mm in diameter, 5 mm thick and weighed about 3.3 gm each. Some Tags were mounted directly onto swimmers' heads using a removable waterproof medical-grade adhesive. They were positioned either on a forehead or behind an ear. Other Tags were mounted on swim goggles or held onto a forehead by an elastic band. The swimmers included children, teenagers and adults of both genders. The swimmers engaged in normal water activities at their own discretion for thirty minutes. All of the Tags stayed on the swimmers. None of swimmers expressed any discomfort with the Tags or expressed a desire to remove a Tag. The only unintentional Yellow Alert that sounded was when an adult swimmer with a Tag mounted behind her ear was resting against the side of the pool with her head inclined back. She was readily identified when the Yellow Alert sounded.
CONCLUSION
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Any of the aspects of the invention of the present invention found to offer advantages over the state of the art may be used separately or in any suitable combination to achieve some or all of the benefits of the invention disclosed herein. | Electronic Tags are mounted on swimmers to reduce their risk of drowning by identifying when their heads are underwater for periods of time which may indicate a dangerous submersion situation, and for triggering corresponding alerts and alarms. In this method, each monitored person is equipped with a lightweight electronic Tag worn on the body that communicates with monitors that issue the alerts and alarms, including audible and visible distress signals. The monitors, in turn, communicate the alarms to receivers used by supervisory personnel, such as lifeguards or parents. The invention may be used in aquatic environments, such as public recreation facilities, pools, waterfronts, and water parks, as well as in more private settings, such as homes, apartment buildings or hotels. | 4 |
FIELD OF THE INVENTION
This invention relates to a bait container or bucket in which water is aerated to keep bait, such as minnows and shrimp, alive and swimming normally until one of the bait is to be selected for use, typically to be hooked on a line of a fishing rod or pole being used by a person, whether a fisherman or fisherwoman.
BACKGROUND OF THE INVENTION
The purpose of a live bait “well”, container or bucket is not only to maintain the bait in good, lively condition, but also to ensure that the bait can be readily, easily and speedily retrieved under exigent conditions encountered when fishing with a fishing rod in one's hands and fish suddenly exhibiting a feeding frenzy. To meet the demands of such conditions, it is critical that the structural components of the “live well”, container or bucket and the manner in which they interact are so designed as to allow a fisherman to choose a bait from those swimming around in the well, container or bucket, under conditions which require that only one of his hands is used to pick out a bait, whether a small fish such as a minnow or a shrimp for use, while holding his fishing rod in the other. It is well known that, when fishing, it is inconvenient and impractical to lay down the rod while attending to retrieving bait from the bait bucket.
A live well for bait is typically substantially larger than a more commonly used container such as a bucket. Whether a live well, a bucket or other container, each may be used in a wide variety of sizes and each may have an arbitrary cross-section chosen for convenience in the particular environment in which the bait is to be used. Commonly used bait containers have cross-sections which are either polygonal or circular; the polygonal ones are typically either rectangular or square; and the ones with a circular cross-section may be either cylindrical or tapered. Most preferred and commonly used is a bait bucket having a cross-section which is either square, rectangular or circular, and one with a circular cross-section may be tapered from top to bottom, the area of the bottom being substantially smaller than the area at the top of the bucket. In the following description, the term “bucket” is used simply because a bucket is commonly used.
A commonly used bait bucket comprises a bucket in which a perforated or porous bowl-shaped container, referred to herein as a colander or perforated basket (hereafter “colander”), is removably, slidably inserted. By “bowl-shaped” is meant that the bowl is approximately concavo-convex. The bucket, in use, is filled with water to a desired level, sufficient to keep the bait alive and in good health for as long as the water is adequately aerated. The bucket is usually covered with a close-fitting substantially rigid lid which is provided with a central opening, at least large enough to allow a person's closed hand or fist to go through the opening to pick out a bait. The opening in the lid is provided with a hinged, perforated or porous flap which allows free flow of air into and out of the bucket while keeping the bait caged in the bucket. A combination of an aerator or “air-pump” powered by a battery is positioned at a convenient location outside the bucket, and an air-hose from the air pump is immersed in the water so as to bubble air under pressure through the water.
An additional feature in a preferred live bait bucket is a drain through which used or stale water can be drained out of the bucket either before it is replenished, or while it is being replenished with water, whether the water is salt water, brackish water or fresh water, and whether the bucket is to be drained on land, or in a boat on the water. Moreover, it is desirable that the drain be opened and closed, with one hand, conveniently, even when the bucket is being drained in a moving boat.
Given the basically simple requirements of an easy-to-use bait bucket, it is to be expected that the ultimate, well-designed, practical, reliable and convenient-to-use bucket would have been marketed and used for a long time. That there have been so many attempts to construct a bait bucket which addresses the problems inherent in the use of prior art bait buckets is evidence that providing the most practical and economical bait bucket for live bait is a difficult challenge.
As will be evident, the difficulty of catching one of only three or four remaining minnows or shrimp in a typical 5 gallon (18.9 liters) bucket, is substantially more difficult than catching one of several dozen swimming in the same bucket. The use of a colander which could be raised and lowered in an aerated bait bucket was disclosed more than a half century ago in U.S. Pat. No. 2,663,115. This construction addressed the requirement that the bait be separated from the water in which they were swimming to afford the fisherman a better chance of catching and using a single bait. However, it is readily apparent that retrieving a single minnow from the water in the minnow bucket disclosed in this '115 patent, necessitates the use of two hands; this requires that the fisherman either put down his rod, or have a second person help.
Comparably old disclosures in U.S. Pat. Nos. 3,039,225 and 3,319,372 use a flexible net as a scoop, which again requires the use of both hands. Still other live bait buckets use complicated gating devices to control the flow of water so as to allow the bait to be separated from the water in which they were swimming.
The problems to be solved:
1. It is critical that all operations on the bucket are able to be executed by a fisherman using only one hand. 2. A single minnow or shrimp is to be retrieved from all the bait in the bucket, and all the bait in the bucket is to be presented out of the water, that is, above or near the surface of the water in the bucket. Therefore, all the bait is to be concentrated in the colander, above or near the surface of the water, when a single bait is to be retrieved. In addition to allowing a single minnow or shrimp to be retrieved from the multiplicity of live minnows and shrimp, retrieving all bait from the water at one time, allows a dead minnow to be singled out and discarded as soon as it is discovered, so that it does not foul the water. 3. Where a colander is to be used, retrieval of the live bait from the water is to be accomplished without allowing any of the bait to escape from the colander, for example, by jumping through the annular space between its periphery and the inner wall of the bucket. 4. The colander, is to be raised with one hand, and once raised, with no continued manual force being exerted to maintain its position, its position above or near the surface of the water is maintained, and the colander is not lowered back into the water due to the weight of the bait in the colander. 5. As is often done in premium bait buckets, a drain is provided to permit water from the bucket to be drained, when desired. This is done with a pet-cock which typically protrudes more than 1 inch (2.54 cm) from the outer surface of the bucket; alternatively, instead of opening a valve, a cap is removed by unscrewing it from the surface of an exteriorly threaded nozzle which projects more than 1″ (2.54 cm) from the outer surface of the bucket. Though either the valve can be opened with one hand, or the cap can be removed with one hand, the location of the exteriorly protruding drain requires that a person bend all the way down to the surface on which the bucket rests, to open the drain. Further, it is easy to damage the exteriorly protruding drain or valve when the bucket is inadvertently banged against the inside of the boat; and it is also easy to lose the cap after it is removed. The seriousness of this problem has, to date, not been recognized. No disclosure in prior art bait buckets suggests how to solve this problem.
Commonly used, aerated live bait buckets which use a colander suffer from one or more disadvantages caused by one or more of the foregoing problems but the buckets are nevertheless in general use. The novel live bait bucket of this invention provides a solution to all the foregoing problems.
SUMMARY OF THE INVENTION
A live bait “well” or container (hereafter “bucket” for convenience) of arbitrary internal cross-section, closed with a substantially rigid lid, is provided with a bait-retrieval assembly constructed with commonly available structural elements so as to provide an unexpectedly functional and reliable bait bucket from which a bait of choice is readily accessed using one hand only. The retrieval assembly comprises a colander supported on an L-shaped frame with twin rectilinear members, laterally spaced-apart in the same plane, which in operation of the retrieval assembly, are near-vertical but critically non-parallel. The colander may be raised with the L-shaped frame and temporarily locked in position, above or near the surface of the water in the bucket, because the lateral distance between the vertical members adjacent the colander near the bottom of the L is less than the lateral distance between them near the top of the L where the vertical members are spaced-apart by a removable cross member. A hinged flap in the lid, is openable with one hand, before or after raising the L-shaped frame, to provide manual access to the bait, all of which is concentrated in the colander. If desired, the flap may be opened concurrently with raising the colander. A single live bait may be retrieved, and the colander returned to the bottom of the bucket by pushing down on the L-frame with one hand only, concurrently closing the flap on the lid of the bucket.
More particularly, a colander having a periphery adapted to be closely adjacent the periphery of the internal walls of the bait container, to preclude a bait from escaping through the peripheral space between the periphery of the colander and the walls of the container, is supported and immovably secured to the lower portion of the L-frame, the members of which are preferably of the same stock, whether rods, struts or tubes. By “a colander having a periphery closely adjacent the periphery of the internal walls of the bait container” is meant that the width of the space between the periphery of the colander and the internal surfaces of the walls of the container is so small that bait cannot escape through the space. When the internal cross-section near the top of the container is greater than the cross-section near the bottom, the diameter of the colander is chosen so as to effectively seal the varying width of the annular or peripheral space, from bottom to top of the container, with a peripheral skirt. Accordingly, the periphery of the colander is provided with a flexible skirt projecting outwardly, and having a radial width sufficient to be closely adjacent, and preferably engage, the inner walls of the container from near its bottom to near its top.
The L-frame is slidably vertically reciprocable through a pair of laterally spaced apart through-apertures in the lid fitted on the bucket. Raising the L-shaped frame, using one hand only on an upper cross-member of the L-shaped frame, raises the colander from a lowered to an elevated position above or near the surface of the water in the bucket. Preferably, a flexible connection such as a cord, connecting the top of the L-shaped handle to a foraminous flap in the lid, raises the flap when the L-shaped handle is raised; the colander, with bait in it, is maintained in the elevated position because the vertical members of the L-shaped frame which are secured in the lid by the bias and friction generated by the “taper” or “wedge-shaped” orientation of the vertical members; when the upper cross-member is pushed downwards, again using one hand only, the colander with live unused bait, is lowered into the water and the flap is automatically closed.
A drain valve is preferably positioned within the bucket, on or near its bottom, and the valve is openable and closable from above the lid of the bucket, using a removable stub handle on a vertical valve stem extending through and above the lid of the bucket. Removing the stub handle permits the lid of the bucket and the retrieval assembly to be withdrawn from the bucket.
In one preferred embodiment of the container is a tapered insulated bucket in which the retrieval assembly is raised and lowered by using the upper cross-tube of the L-shaped frame; the cross-tube connects the upper ends of the frame's pair of spaced-apart rectilinear vertical members; having upper ends and lower ends, and a lower cross-tube connects the ends of a pair of spaced-apart horizontal rectilinear members attached to the lower ends of the vertical members, so that the horizontal members are substantially orthogonal relative to the vertical members; to retrieve a bait, only one hand is used to raise the L-shaped frame and the colander; if the flap on the lid is not connected with a string or cord to the cross-member of the L-shaped frame, the same hand (since the other hand may be holding a fishing rod) lifts the flap to expose the opening in the lid; the same hand retrieves a bait and then pushes down on the upper cross-tube to lower the colander into the water; the colander is supported on the horizontal members of the frame; the vertical members are in mirror image relationship with one another, and spaced so that the distance between the longitudinal center lines of the lower ends is less than the distance between longitudinal center lines of the upper ends; the apertures in the lid are spaced-apart corresponding to the distance between the upper ends so that the upper portions of the vertical members are slidable downwards in the apertures; but the spacing of the apertures is less than the distance between the lower ends so that when the vertical members are raised, they are wedged near their lower ends in the apertures of the lid; the colander is provided with a peripheral skirt which preferably engages the inner surface of the tapered bucket. To keep the water cool, the bucket is insulated.
In another preferred embodiment the bucket is cylindrical, and the colander has a peripheral diameter such that the colander is slidable within the bucket from a position near its bottom to a position above or near the surface of the water in which the bait is kept alive. The L-shaped frame is substantially the same as the one used for a tapered bucket; and to keep the water cool, the bucket is insulated.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and additional objects and advantages of the invention will best be understood by reference to the following detailed description, accompanied with schematic illustrations of preferred embodiments of the invention, in which illustrations like reference numerals refer to like elements, and in which:
FIG. 1 is a perspective view of a tapered bait bucket in which the L-shaped frame of the retrieval assembly is in the “down” position and the opening (for access with one's hand) in the lid is closed by a flap.
FIG. 2 is a perspective view of the bait bucket shown in FIG. 1 , in which bucket the L-shaped frame is in the “up” position and the opening in the lid is open because the flap is raised. An “air-pump” is shown clipped or otherwise removably mounted on the bucket, preferably to a bracket molded into, and forming an integral portion of the periphery of the lid.
FIG. 3 is a perspective view of the bait-retrieval assembly of FIG. 2 showing the positioning of the tapered, wedge-shaped vertical members relative to the open flap, the diameter of which flap is preferably slightly greater than the spacing between the vertical members when a colander is in the “up” position.
FIG. 4 is a perspective view of a bait-retrieval assembly for a cylindrical bucket, showing a colander having a periphery without a skirt, allowing the periphery of the colander to be slidably disposed within the cylindrical walls of the bucket so as to seal off the annular space between the periphery of the colander and the walls of the bucket, and prevent bait from escaping out of the colander into the water beneath.
FIG. 5 is a bottom perspective view of the bait-retrieval assembly of FIG. 2 showing the positioning of the colander supported between spaced-apart horizontal rods or tubular members of the L-shaped frame; the slot in the colander is for passage of a vertical valve stem to open or close a drain valve in the bottom of the bucket.
FIG. 6 is a top perspective view of the bucket in which the bait-retrieval assembly has been removed to show the drain valve in the bottom of the bucket and the vertical valve stem to operate the valve.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the various Figures in the drawing, and more particularly to FIGS. 1 and 2 , it is seen that a commonly commercially available, “standard” tapered 5 gallon (18.9 liters) bucket is preferably used to provide the bait bucket designated generally by reference numeral 10 in which a bucket 11 contains a retrieval assembly “RA” slidably inserted into the bucket. The bucket is preferably provided with a handle 12 for easy portability and a substantially rigid lid 40 with a peripheral flange 41 adapted to snap over and removably lock onto the upper periphery of the bucket. Such tapered 5 gal buckets have an inner diameter near the base (at the bottom) of about 10.25 ins. (26.0 cm) and an inner diameter near the top of about 11.25 ins. (28.57 cm) and are readily available commercially. Smaller or larger buckets may be used, if desired. The bucket 11 and lid 40 may be of metal or a synthetic resinous material (“plastic”), but is preferably of high density polyethylene (HDPE) or some other readily available thermoformable synthetic resinous material which is not susceptible to corrosion and can be readily cleaned so as to provide an environment in which the bait will happily survive.
The lid 40 is preferably provided with a central access opening 42 having a diameter in the range from about 4 ins (10.16 cm)-7 ins (17.78 cm) to allow a person to thrust his/her hand into the otherwise closed bucket 11 . The central access opening 42 is closed with the flap 43 pivotally connected to the lid 40 by a hinge 44 (see FIG. 3 ) which has a bias such that the weight of the open flap 43 is sufficient to urge the flap into the closed position. The lid 40 is also provided with an opening 47 for passage of vertical valve stem 61 .
If the bait is to live and be used over an extended period of time, or even several hours, and is to remain healthy, the bait bucket is additionally provided with an “air-pump” or aerator 70 to aerate the water placed in the bucket 11 . The air pump 70 comprises in combination (i) a battery 73 to power the air-pump; (ii) an air-tube 71 inserted through an access opening 46 in the lid 40 and (iii) an air-dispersing means or bubbler 72 immersed in water in the bucket, to which bubbler the air-tube is connected at one end, the other end being connected at with the output of the air pump. The bubbler 72 is used to create air bubbles that are bubbled through the water to provide better contact of the air with the water, thus increasing the efficiency of getting oxygen absorbed into the air.
Referring particularly to FIG. 2 , the flap 43 is in the open position. Though it is not necessary to lock the flap, in the closed position, to the lid, it is desirable to do so. To this end, the periphery of the flap 43 is provided with a flexible V-shaped projection 48 having a detent (not visible) on the outer surface of the distal arm (relative to the periphery of the flap) of the V-shaped projection. A slot 49 is provided in the lid 40 at a location in registry with the V-shaped projection 48 when the flap 43 is in the closed position, and the flap may be locked into the closed position by pressing the V-shaped projection into the slot 49 .
Retrieval assembly RA (shown in FIG. 3 ) includes an L-shaped frame 21 , the upper portion 22 of which frame is shown in the “up” position, wedged between apertures in the lid 40 , to raise colander 50 . The upper portion 22 includes spaced-apart vertical tubular members (“tubes”) 23 and 24 , preferred for convenience and economy, which are slidably disposed in correspondingly spaced-apart openings 45 in the lid 40 , and the tubes are preferably connected at their upper ends by cross-tubular member (“cross-tube”) 25 to provide a convenient gripping handle to raise and lower the L-shaped frame. The rigidity (referred to herein) of the lid is such that the through-apertures or openings 45 in the lid are not distensible by up-and-down movement of vertical members 23 and 24 of the L-shaped frame 21 in the lid. Though each of the tubes may be replaced with a solid rod, whether of metal or plastic, all tubes shown herein are of either polyethylene (PE), or chlorinated polyvinylchloride (CPVC) or polyvinylchloride (PVC). The cross-tube 25 is connected to tubes 23 and 24 with right angle ells 26 and 27 in which the ends of the cross-tube are adhesively secured. The ells 26 and 27 are removably secured to the upper ends of the vertical tubes 23 and 24 respectively, with spring clips 28 so that, when the cross-tube and ells are removed, the upper ends of the vertical tubes will, when pulled downwards through the lid, pass through the spaced-apart apertures in the lid 40 , to permit disassembly of the retrieval assembly.
Referring further to FIG. 3 there is shown the retrieval assembly RA with the flap 43 in the open position, preferably openable concurrently with raising of the L-shaped frame because the flap 43 is connected with a flexible connection “FC” to the L-shaped frame. The lid 40 is shown as being temporarily locked in position on the vertical tubes 23 and 24 , near the lower portion 29 of the L-shaped frame 21 . The spacing between the vertical tubes 23 and 24 near the upper portion 30 of the frame is such as to afford slidable movement of the upper portions of the tubes in the their respective spaced-apart openings 45 in the lid 40 . However, the spacing between the vertical tubes 23 and 24 near the bottom of the frame is less than that in the upper portion, and so chosen as to frictionally bind the vertical tubes in their openings 45 since the openings 45 are spaced apart from each other at a distance which is greater than the spacing between the vertical tubes 23 and 24 near the lower portion 29 of the L-shaped frame 21 .
For example, in an L-shaped frame adapted for use in a “standard” 5 gal bucket, the members are cut from 0.5″ CPVC pipe which has a nominal outside diameter of about 0.625″ (15.875 mm). The vertical members are spaced apart such that the distance between their longitudinal center lines at the top is about 5.375″ (13.65 cm); and the distance between their longitudinal center lines at the bottom is about 5.25″ (13.335 cm) so that the vertical tubes are positioned in mirror-image relationship with each other.
The vertical tubes 23 , 24 are spaced-apart in one half of the area of the lid, and the tubes are symmetrically disposed relative to the central access opening 43 . The lower ends of the vertical tubes 23 and 24 are connected to spaced-apart horizontal tubes 31 and 32 (see FIG. 5 ) between which is positioned a colander 50 having a bowl with a diameter, measured across the periphery of its opening, which diameter closely matches, but is slightly less, from about 10 mils (254 micrometers) to 50 mils (1270 micrometers) than the inside diameter of the bottom of the bucket, so as to be snugly slidable into the bottom of the bucket 11 . The colander 50 may be made of a non-corroding metal such as aluminum or copper, but for economy, is preferably of a synthetic resinous material, typically polyethylene, and relatively thin, preferably in the range from about 10 mils (254 μm) to 50 mils (1270 μm) thick, to save on weight and material, yet adequately support the weight of the bait to be kept in the bucket.
The colander 50 is preferably bowl-shaped, having a depth in the range from about 2″ (5.08 cm)-6″ (15.24 cm) is provided with perforations 51 small enough, that is, less than 0.25″ wide, so as to preclude a bait from passing through one of the perforations. In addition, the colander is provided with three relatively larger openings. Two of the three openings (not numerically identified) are slightly, that is, in the range from 5 mils-10 mils wider, than the diameter of each vertical tube 23 and 24 , and the openings are spaced-apart so as to correspond to the distance between the lower portions of the vertical tubes 23 and 24 . The vertical tubes are inserted through the two openings and the colander is fixedly secured to these tubes, preferably adhesively, so as to locate the colander and have it rest between and be supported by horizontal tubes 31 and 32 , centrally in the bucket.
For additional support and to strengthen the L-shaped frame 21 , the horizontal tubes 31 and 32 are interconnected by a cross-tube 33 , each end of which is securely fixed in right angle ells 34 and 35 respectively, which are also securely fixed to the ends of the horizontal tubes 31 , 32 .
As a result of the lateral spacing between the lower portions of the vertical tubes 23 and 24 being less than the spacing between their upper portions, an upward thrust of the assembly caused by pulling up on the upper portion of the L-shaped frame, causes the lower portions of the tubes 23 and 24 to become wedged in the lid 40 until the bait is chosen and the L-shaped frame is forced down through the lid 40 .
As mentioned hereinabove, a commercially available “standard” bucket 11 is tapered so that there is a difference of about 1 inch (2.54 cm) between the diameters near the top and the bottom of the bucket. It will now be evident that, when the colander is raised into the upper portion of the bucket to be able to choose a bait, the annular space between the periphery of the colander and the inner surface of the upper portion of the bucket will be about 0.5″ (1.27 cm), and large enough to permit a bait to jump out of the colander and into the water below the colander. To avoid losing a bait from the colander in such a manner, the periphery of the colander is provided with a continuous flexible skirt 52 fixedly secured to the periphery of the colander so that the skirt is outwardly, generally radially directed, and having a width sufficient to seal the annular space because the skirt is biased against the inner walls of the bucket. When the L-shaped frame is raised and lowered, the outwardly, generally radially projecting skirt 52 engages the cylindrical inner surface of the bucket so that the periphery of the skirt is biased against the inner surface sufficiently to seal the annular escape path of the bait. Alternatively, the periphery of the skirt is so closely adjacent the inner surface of the inner wall of the container as to seal the annular escape path of the bait. By “closely adjacent” is meant that the width of the annular or peripheral escape path depends upon the size of the bait being used, this width being not greater than the width of the body of the shrimp or minnow being used. Typically this width is less than 6.35 mm (0.25 in), but may be larger if larger bait having a body width of 12.7 mm (0.5 in) is to be used. When this width is reduced to zero, the periphery of the skirt engages the surface of the inner walls of the container irrespective of its cross-section.
Referring to FIG. 4 there is shown a retrieval assembly RA′ for a common, “standard” cylindrical 5 gal bucket (not shown) 11 ′ which is also commercially available. The retrieval assembly RA′ is similar to the retrieval assembly RA described hereinabove except that the colander 50 is not provided with a skirt because the bucket is cylindrical and the diameter of the periphery of the colander which closely matches, but is slightly less than that of the inner diameter of the bucket near the bottom, also closely matches the inner diameter at the top, precluding the escape of bait. The bucket 11 ′ is provided with insulation means 13 , shown in FIG. 4 , such as a synthetic resinous foam, preferably polystyrene foam, which covers the exterior circumferential surface of the bucket to keep the water in the bucket cool. Such insulation may also be provided for the tapered bucket 11 . Alternatively, the bucket may be molded as an insulated bucket with a continuous internal skin of polymer, a continuous outer skin of polymer and foamed polymer sandwiched in between the inner and outer layers, as is well known in the art.
In both RA and RA′, the colander 50 is provided with a vertical slot 53 having a width (measured laterally) sufficient to slidably closely accommodate vertical valve stem 61 of a drain assembly 60 which is essentially completely contained within the bucket 11 (see FIG. 6 ). Though a drain assembly is not essential, it is highly desirable, periodically, to drain “stale” water and replace it with “fresh” water, if the bait bucket 10 is to be used for more than several hours.
The drain assembly 60 includes an on/off rotary or ball valve 62 one end of which is in open fluid communication with water in the bucket; the other end of the ball valve is connected to one arm of a right angle ell 63 . The other arm of the ell 63 is connected to one end of a stub end 64 . The other end of the stub end 64 , which is threaded on its surface, protrudes through an aperture in the sidewall of the bucket for a distance of about 0.5″ (1.27 cm), just sufficient to permit the threaded end to be locked against the outer surface of the bucket with a locking ring (not shown). Vertical valve stem 61 , when rotated, opens and shuts the valve 62 . The upper end of the vertical valve stem 61 is securely fixed in a right angle ell 65 preferably extended with a stub end 66 to provide a handle for easily turning the valve from a closed to an open position, and vice versa, with one hand, leaning over only sufficiently to reach the top of the bucket.
For use at night, a light 80 is preferably removably mounted on the cross-tube 25 of the L-shaped frame 21 so as to shine onto the flap 43 . When the flap is opened, the light shines directly onto the bait concentrated in the colander.
The tapered bucket 11 is readied for use by filling it with water to a level in the upper portion of the bucket so as to have an acceptably large volume of water in which to hold live bait to be introduced into the bucket. The right angle ell 63 and the stub end 64 are removed from the lower end of the vertical valve stem 61 . The cross-tube 25 and right angle ells 26 and 27 are removed form the retrieval assembly RA and the vertical valve stem 61 is passed through the vertical slot 53 in the colander 50 . The vertical tubes 23 and 24 , are inserted through spaced-apart access openings for the tubes in the lid 40 , and the vertical valve stem 61 is inserted through passage 47 in the lid. With the colander 50 in the bottom of the bucket, the lid 40 is snapped shut over the periphery of the bucket 11 and the right angle ell 63 with stub end 64 is replaced and locked in place on the bottom of vertical valve stem 61 ; and the cross-tube 25 and right angle ells 26 , 27 are replaced and locked into place on the protruding upper ends of vertical tubes 23 and 24 . The live bait is now introduced through the central access opening 42 and the battery switched on to start the aerator and bubble air through the water.
To retrieve a bait while still holding his fishing rod in one hand, the cross-tube 25 is raised with his free hand until the taper causes the vertical tubes to bind in their openings in the lid 40 bringing the colander 50 to a height above or near the surface of the water, with the bait concentrated in the colander and out of the water. The cross-tube 25 is released and the flap 43 is raised with the free hand, diametrically opposite ends of the flap coming to rest against the vertical tubes 23 and 24 . If provided with a flexible connection, such as a piece of cord or string, between the flap 43 and the upper portion of the L-shaped frame 21 , preferably by attaching one end of the cord to the cross-tube 25 , the flap 43 is concurrently raised when the cross-tube is raised. With the same free hand he chooses a bait, and with the bait still in his hand, pushes down on the cross-tube 25 to thrust the colander 50 back to the bottom of the bucket. The flap closes automatically when the L-shaped frame is lowered.
Having thus provided a general discussion, described the overall live bait bucket in detail and illustrated it with specific illustrations of the best mode of making and using it, it will be evident that the invention has provided an effective solution to an age-old problem. It is therefore to be understood that no undue restrictions are to be imposed by reason of the specific embodiments illustrated and discussed, and particularly that the invention is not restricted to a slavish adherence to the details set forth herein. | A container for live bait is provided with a bait retrieval assembly of readily available structural components which are combined in an unexpectedly useful manner to allow all operations to be carried out using one hand only. The container, which is closed with a substantially rigid lid, may be of arbitrary cross-section but is preferably either cylindrical or tapered. The bait retrieval assembly includes an L-shaped frame comprising a pair of vertical members and a pair of horizontal members on which a bowl-shaped colander is supported. The vertical members are reciprocable through openings in the lid. The vertical members are required to be in mirror image relationship with one another, and laterally spaced-apart so that the distance between the longitudinal center lines of the members in the bottom portion of the L is less than the distance between longitudinal center lines of the members in the upper portion of the L. The critical wedge-shaped configuration of the vertical members of the L-shaped frame allows the colander, with the bait in it, to be temporarily locked in position, above or near the surface of the water for easy access with one hand. The container is preferably provided with an internal drain assembly and an aerator. | 0 |
TECHNICAL FIELD
This invention has particular use in the mining, road planing and earth digging fields. More specifically, the invention relates to arrangements by which a bit lug having a socket therein to receive a bit is located in a base member. The bit lug is provided with a retainer for releasably securing it within the base member. The instant invention resides in a relationship among the bit lug, base member and retainer such that when these parts are in their assembled, operative condition the retainer is protected from damage and from accidental removal by the forces and abrasive conditions encountered during a mining, road planing or earth moving operation.
BACKGROUND ART
The present invention is especially applicable to mining machines and the like of the type having a primary drive member to which is affixed one or more base members each adapted to receive a bit lug which in turn receives a bit or cutting tool. The drive member, which in turn is driven by appropriate mechanisms, may take a number of forms such as a chain, a rotating wheel, a rotating drum, or a rotating arm and the like. The bits or cutting tools, which may also be those found in machinery other than mining, such as road working and earth moving equipment, may also take various forms such as mining machine cutter bits, road ripping elements, digger teeth and the like.
The bit lug, also known in the trade as a bit block or bit holder, may receive various kinds of bits or cutting elements. To this end the lug is provided with a perforation designed to receive the shank of the particular style of bit for the particular work to be performed. The precise relationship between the bit lug and bit does not constitute a direct part of the instant invention. Various means may be provided for retaining the bit or cutting element within the lug; again these do not constitute a direct part of the instant invention. By the same token the invention is not directly concerned with the particular kind of equipment to which the base member, that which receives the bit lug, is affixed. The invention is primarily concerned with the manner by which the bit lug is secured within a cavity provided for it in the base member. As indicated herein, means are provided to retain the bit lug within the base member and the invention is directly concerned with protecting these latter means.
No search of the prior United States patent art has been made in connection with this invention. It is known, however, that there are many patents which show various relationships between bit lugs and base members. Prior art workers recognized the importance of providing arrangments by means of which the bit lug itself, as distinguished from the bit per se, could be easily and readily removed from the respective base member in which it was mounted. A number of "pin-on", "wedge-on" and other arrangements were developed for accomplishing such result. U.S. Pat. No. Re. 28,310 discloses a popular "pin-on" arrangement for securing a bit lug to a base member. Various "wedge-on" arrangements are shown in U.S. Pat. Nos. 3,342,531; 3,834,764; 4,057,294; 4,275,929 and 4,337,980. (Patents such as U.S. Pat. Nos. 3,397,012 and 3,622,206 disclose various means and arrangements for enabling quick and easy removal of a bit from a bit lug. Other such means and arrangements are shown in U.S. Pat. Nos. 2,965,365 and 3,114,537.)
There is other art which is at least indirectly pertinent. U.S. Pat. Nos. 3,679,265 and 3,888,133, for example, show chains made up of various interdigitated bit-carrying links, connecting links, spacers, connecting pins and retaining means. U.S. Pat. No. 3,888,133 is of interest in that it does disclose an arrangement by which the means to retain a connecting pin within a number of connecting links, bit-carrying links and spacers is prevented from being accidentally dislodged and is protected from wear. Some of the principles of this latter patent are adopted for use in the instant invention. In this connection, U.S. Pat. No. 3,397,012 (FIG. 12) is also of interest.
DISCLOSURE OF THE INVENTION
The combined base member and bit holder with protected retainer which comprises this invention includes a relationship between the base member and bit holder such that the bit holder may be inserted within the perforation provided for it in the base member and moved to an initial position wherein the retainer may be placed on an end of the bit holder which protrudes outside of the base member, whereafter the bit holder is moved axially so as to bring the retainer at least partially within the base member, and then a spacer is mounted between the head of the bit holder and the front of the base member to maintain the bit holder and base member in proper relationship. In one embodiment of the invention a boss is provided on the base member and the spacer comprises a split ring the ends of which will engage about the sides of the boss. In other embodiments of the invention means are provided to capture the ends of the spacer so as to prevent the spacer from being spread by the forces encountered during the mining or other operation, thereby ensuring that the spacer will stay in place and the bit holder and base member remain in operative condition with the retainer held in a protected position. In some embodiments of the invention the bit holder is provided with a flat to enable it to clear the boss. In other embodiments of the invention the head of the bit holder is provided with a notch to receive the boss when the bit holder is moved to its initial position for insertion of the retainer. Some embodiments also include another notch to enable a drift or the like to be inserted between the spacer and bit holder so as to enable the spacer to be removed when it is necessary to replace the bit holder.
In all of the embodiments the arrangement is such that when the bit holder and base member are in their operative position the means which retains the bit holder within the base member is at least partly protected by the base member. This protects the retainer from damage by the conditions encountered during the working operation and it also prevents inadvertent removal of the retainer whereby to ensure that the bit holder is securely held within the base member at all times.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the main portion of a base member comprising a part of the invention.
FIG. 2 is an auxiliary view of the base member of FIG. 1 and taken from the right side thereof, looking along the axis of the perforation which will receive a bit holder.
FIG. 3 is a side elevation of a bit holder used in this invention.
FIG. 4 is an end view of the bit holder of FIG. 3 taken from the right side thereof.
FIG. 5 is a plan view of a spacer which may be used with this invention.
FIG. 6 is a plan view of one type of retainer which may be used with this invention.
FIG. 7 is an assembly view, partly in section, showing the bit holder of FIG. 3 located in its initial position within the base member of FIG. 1.
FIG. 8 is an assembly view showing the bit holder of FIG. 3 located within its final position in the base member of FIG. 1, the retainer having been placed on the bit holder when in the FIG. 7 position and the spacer having been driven home in the FIG. 8 position.
FIG. 9 is a cross-section taken on the line 9--9 of FIG. 8.
FIG. 10 is a view similar to FIG. 9 but showing a modified spacer and boss.
FIG. 11 is a view similar to FIG. 8 but showing a different type of retainer.
FIG. 12 is an exploded assembly view, partly in section, of a somewhat different type of bit holder along with the base member, retainer and spacer comprising one modification of the invention.
FIG. 13 is a plan view of a modified spacer.
FIG. 14 is a view, partly in section, showing the bit holder, base member, retainer and spacer of FIGS. 12 and 13 in their assembled condition.
FIG. 15 is a sectioned side view of a modified bit holder, base member assembled combination.
FIG. 16 is a view taken on the line 16--16 of FIG. 15.
FIG. 17 is a sectioned side view of a modified assembled bit holder, base member combination.
FIG. 18 is a view taken on the line 18--18 of FIG. 17.
FIG. 19 is a sectioned side view of another modification of assembled bit holder and base member.
FIG. 20 is a view taken on the line 20--20 of FIG. 19.
FIG. 21 is a sectioned side view of another modification of assembled bit holder and base member.
FIG. 22 is a view taken on the line 22--22 of FIG. 21.
FIG. 23 is a perspective view of another embodiment of a bit holder which may comprise a part of the invention.
FIG. 24 is a sectioned side view showing the initial position of the modified bit holder of FIG. 23 located within a base member generally like that of FIG. 1.
FIG. 25 is a sectioned side view showing the combination of FIG. 24 in its completely assembled condition following placement of the retainer on the bit holder and the driving home of the spacer.
FIG. 26 is a plan view of a modified boss.
FIG. 27 is a plan view of a modified spacer.
FIG. 28 is a plan view of a modified spacer.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIGS. 12-14, the basic invention is disclosed. A base member 35 is depicted as adapted to receive therein a bit holder 36. To this end the base member 35 is provided with a perforation having diameters 37 and 38 adapted to receive the corresponding portions 39 and 40 of the bit holder 36. The bit holder 36 also has an annular head 41 adapted to overlie the perforation 37. The bit holder also has an annular groove 42, in this instance, adapted to receive an annular retainer 43 which may be resilient in nature. The base member 35, in this instance, is provided with an annular undercut or notch 44 adapted to receive the retainer 43.
To assemble the bit holder within the base member, the bit holder is inserted through the perforations 37 and 38 to a position where the rear face 45 of the annular head 41 may abut the front face 46 of the base member 35 at which point the notch 42 in the bit holder 36 will project beyond the rear face 47 of the base member 35 so that the retainer 43 may be located directly in the groove 42. The bit holder 36 is then moved axially in the opposite direction within the base member 35 so as to create a space between the bit holder head rear face 45 and the base member front face 46 so that a spacer 48 can then be engaged about the bit holder portion 39 between the two faces 45 and 46. The relationship is such as to ensure that this brings the retainer 43 at least partially within the notch 44 whereby the retainer is protected from the forces and fines encountered during a mining operation, for example, and the retainer is also prevented from being inadvertently dislodged.
From the foregoing, therefore, it will be observed that the bit holder 36 is first placed within the base member 35 so that the groove 42 is accessible from the rear face 47 of the base member 35, the retainer 43 is then installed in the bit holder groove 42, and after this the spacer 48 is installed between the faces 45 and 46. In this manner the retainer 43 is brought into the base member and at least partially received in the base member notch 44 for restraint and protection. It should be observed that this relationship is such that the bit holder may also rotate within the perforation provided for it in the base member.
The spacer 48 may have any appropriate cross-section. The inner curvature 48a of the retainer is such that the ends 48b will have to be spread apart in order to pass around the bit holder portion 39 and in order that the spacer 48 will be arranged about such portion 39 when it is driven home. The distance between the ends of the legs 48b will be somewhat less than the outer diameter of the bit holder portion 39. The inner diameter 48a of the spacer 48, however, is preferably slightly greater than the outer diameter of the bit holder portion 39. The spacer 48 will have spring tension built into it due to its shape and/or the material from which it is made.
The arrangement of FIGS. 12-14 demonstrates the basic invention of providing a relationship among the base member 35, bit holder 36, retainer 43 and spacer 48 such that the retainer is drawn at least partly within the base member so as to be protected from undue wear and dislodgment. That particular arrangement, however, while generally satisfactory, does present some problems. Except for its frictional engagement with the bit holder face 45 and base member face 46, and with the bit holder portion 39 via the leg ends 48b, there is nothing to prevent the spacer 48 from rotating and this could cause undue wear. Additionally, fines and the like may accumulate between the leg ends 48b and the open overhang of the bit holder face 45 in the region of such ends. Furthermore, there is less bearing area for the underface 45 of the bit holder head 41. These possible shortcomings, however, may be overcome in various ways as will now be discussed.
In the various figures like reference numerals will be used to designate like parts. Thus, referring now to FIGS. 1-9, a base member 35 is again illustrated as having coaxial perforations 37 and 38 designed to receive the portions 39 and 40 of a bit holder 36. The retainer to be received within the annular groove 42 is shown in this instance as comprising a split ring 43 (FIG. 6). This retainer 43 will eventually be received within the annular groove 44 provided in the base member 35. The spacer is also indicated in this instance as comprising a split ring 48 (FIG. 5).
The arrangement of FIGS. 1-9 so far described is like that of FIGS. 12-14 but modifications have been made. First, the base member 35 has been provided with a boss 50 on its front face 46 adjacent the perforation 37 and having its major thickness being substantially the same as the thickness of the spacer 48, see FIG. 8. This boss 50 provides additional bearing area for the rear face 45 of the bit holder head 41; it also serves to prevent rotation of the spacer 48 by reason of the fact that the ends 48b of the spacer are adapted to straddle the sides of the boss 50, see FIG. 9.
Second, the bit holder of FIGS. 1-9 has also been modified. The head 41 of the bit holder 36 has been provided with a flat 41a substantially in line with the outer diameter of the bit holder portion 39. This enables the head 41 to clear the boss 50 when the bit holder is inserted within the base member for installation of the retainer 43, see FIG. 7. Preferably at this point, with head face 45 abutting the base member front face 46, there is a small clearance between the shoulders 37a and 39a.
Third, the relationship among the parts has also been modified somewhat in that, in this particular embodiment, when the spacer 48 is installed the retainer 43 is drawn completely within the base member 35 as permitted by the annular notch or groove 44, see FIG. 8.
In all of the depictions so far discussed the bit holder 36 has been illustrated as provided with a shank receiving perforation 51 to receive the shank of a cutting bit (not shown) and an annular notch or groove 52 to receive some sort resilient retainer (also not shown) to maintain the bit shank within the perforation 51. As noted earlier, however, the exact nature of the bit and the manner in which it is held within the bit holder do not constitute a limitation on this invention.
FIG. 10 depicts a slightly different arrangement and relationship between the spacer 48 and boss 50. The side walls of the boss 50 are shown as slightly tapered towards the perforation 37 which receives the bit holder portion 39, and the ends 48b of the spacer 48 are slightly curved. This makes the spacer easier to install. This also depicts the type of clearance fit preferred between the inner diameter 48a of the spacer 48 and the outer diameter of the bit holder portion 39.
FIG. 11 is generally similar to FIG. 8 but it illustrates the use of a roll pin 53 in place of the retainer 43; this roll pin will be press fitted into a hole provided for it towards the end of the bit holder 36 when that end extends beyond the rear face 47 and the exposed ends of this pin will eventually be received within the groove 44 as shown in this FIG. 11.
The various arrangements of FIGS. 1-11 do prevent the spacer 48 from shifting position once it is installed between the head 41 of the bit holder 36 and the front face 46 of the base member 35, and its free ends 48b brought into engagement with the sides of the boss 50. In some instances, however, the forces and fines encountered during mining operations, for example, are so severe as to cause the spacer legs to be spread apart whereupon the spacer may be lost and eventually even the bit holder. Various structures for preventing this are illustrated in FIGS. 15-22. Again, like reference numerals are used to designate like parts throughout the figures.
In the arrangement of FIGS. 15-20 the boss 50 has been illustrated as extending clear across the base member 35. In FIGS. 15 and 16 the boss 50 is depicted as provided with a pair of arcuate indentations 54 into which the free leg ends 48b of the spacer 40 are forced when the spacer 48 is driven home. In FIG. 16 the ends 48b do not contact the side walls of the boss extension 55 although this could be arranged if desired. It will be apparent, however, that by locating the spacer ends 48b within the arcuate indentations 54 it will make it very difficult for the forces encountered to spread the spacer legs 48 enough to permit the spacer 48 to be lost.
The arrangment of FIGS. 17 and 18 is generally similar to that of FIGS. 15 and 16 differing primarily in the type of notch 54a provided in the boss 50. The side walls of the boss extension 55 are tapered so as to direct the curved ends 48b of the spacer 48 into the arcuate socket-like notches 54a. This is generally like the arrangement of FIG. 10 but with the enlarged boss 50 modified to provide the additional notches 54a. When the spacer 48 is driven home the curved leg ends 48b will pass into the notches 54a and engage the notch overhang 54b. This prevents the legs from being spread and maintains the spacer 48 in desired position whereby to retain the bit holder 36 within the base member 35. The arrangement is again such that the retainer 43 is completely located within the arcuate groove or notch 44.
The arrangement of FIGS. 19 and 20 is generally similar to that shown in FIGS. 17 and 18 except that the legs 48b do not contact the tapered sides of the boss extension 55 and the boss, notch overhang 54b is more pronounced.
The arrangement of FIGS. 21 and 22 is somewhat different in that the kind of boss illustrated in FIGS. 15-20 has been eliminated and replaced by a pair of members 56. These members 56 have an inwardly protruding surface 56a past which the ends 48b of the spacer 48 are forced when the spacer is driven home between the face 45 of the head 41 of the bit holder 36 and the front face 46 of the base member 35. When the leg ends 48b snap into place beneath the overhang 56a, such overhang will resist spreading of the spacer and thereby prevent its accidental dislodgement from the combination of bit holder, base member, retainer and spacer. A modified boss-like member 55a may also be utilized.
FIGS. 23-25 illustrate an embodiment of the invention which incorporates a full-headed bit holder similar to that shown in FIG. 12, (i.e., one without a flat therein such as the flat indicated at 41a in FIG. 7), with a base member 35 having the boss 50 thereon. To this end the bit holder 35 has the head 41 thereof provided with a transverse notch 41b. The notch 41b is sufficient to accommodate the boss 50. The bit holder 36 is first placed within the base member 35 so that the boss 50 is received in the notch 41b; at this point the lower face 45 of the bit holder head 41 will abut the front face 46 of the base member and the retainer groove 42 will project beyond the bottom or rear face 47 of the base member so that the retainer 43 may be installed in the groove 42. At that point the bit holder may be pulled outwardly so that the retainer 43 is received within the groove 44 and then the bit holder 36 may be rotated so that the bit holder head face 45 rests on the boss 50. This simplifies the installation of the spacer 48 since the operator does not have to hold the bit holder 36 in position; the boss 50 and face 45 do this for him as is also true in other embodiments, e.g., that of FIGS. 7 and 8. The spacer 48 is then driven home and the arrangement of spacer 48 and boss 50 may be like that shown in various of the other figures, e.g., FIGS. 12-14.
FIGS. 23-25 also illustrate another feature of the invention, namely, the provision of a second, vertical notch 41c which may be used should it become necessary to withdraw the spacer 48 so as to change bit holders 36. The notch 41c has been illustrated in the FIGS. as located centrally of the notch 41b but this is not a fixed requirement. The notch 41c may be located anywhere around the periphery of the head 41 of the bit holder 36. The purpose of the notch 41c is to permit insertion of a drift or the like to be engaged between the spacer 48 and bit holder body portion 39. The notch 41c could, of course, also be incorporated in others of the various bit holder heads 41 illustrated throughout these drawings.
The arrangement of FIGS. 26 through 28 discloses other modifications of the invention. The boss 50 is generally like that shown in FIG. 20. The spacer 48 of FIG. 28 is similar to the other spacers illustrated in that the distance between those leg ends 48c which are closest to each other is less than the outer diameter of the bit holder portion which they will have to pass while the inner curvature 48a is greater than such outer diameter. During installation, the leg ends 48c will first be forced about the bit holder portion 39 and then guided by the slanted boss surface 54c to a position where they will snap into position beneath the boss abutment surface 54b and thus secured within the boss 50.
In FIG. 27, the shortest distance 48d between the leg ends is slightly greater than the outer diameter of the bit holder portion about which they will pass during installation. These leg ends, however, will be moved toward one another as the end portions 48b pass by the boss portions 54c whereafter those end portions 48b will snap into position beneath such boss portions 54c as permitted by the boss notches 54a. This arrangement makes it possible for the installer to first move one leg end 48b into a notch 54a beneath a boss portion 54c and then to drive the other leg end home. This requires less alignment effort by the installer than do others of the modifications of this invention.
It will be apparent to those skilled in the art that modifications may be made in this invention without departing from the scope thereof. It is to be further understood, therefore, that while this invention has been described in connection with certain particular structures and arrangements, the invention is not to be limited to those particular structures and arrangements except insofar as they are specifically set forth in the subjoined claims. | The combined base member and bit holder with protected retainer which comprises this invention includes a bit holder adapted to receive the shank of a suitable cutting bit. The bit holder has a head which permits movement of the bit holder within the base member so as to expose means to receive a retaining member while that portion of the bit holder protrudes beyond the base member. The base member is provided with an opening or recess to receive the retainer so as to prevent accidental dislodgement. After installation of the retainer the bit holder is moved within the base member so as to engage the retainer at least partly in the recess provided in the base member for it, whereafter a spacer is driven between the head of the bit holder and body of the base member to hold the bit holder in place. A boss may be provided on the base member to prevent undue movement of the spacer. Means may also be provided in conjunction with the boss and/or base member to prevent the legs of the spacer from being spread so that the spacer also is prevented from accidental dislodgement. The bit holder may be provided with a flat to let it pass by the boss or it may be provided with a notch to receive the boss when the bit holder is moved to its initial position for installation of the retainer. | 4 |
FIELD OF THE INVENTION
[0001] The invention relates to an apparatus and method which allows the user of a microscope to automatically detect and quantify particle distributions in biological and medical microscopic specimens.
INTRODUCTION TO THE INVENTION
[0002] In order to visualize and identify the location of specific antibody-antigen complexes, researchers use known methods.
[0003] When working with a light microscope, it is possible to associate the antibody with fluorescent markers that, with correct illumination, reveal the position of the desired complex. Unfortunately, the maximum resolution of the light microscope is not sufficient to permit the detailed identification of the sites where the antibody-antigen complex is located.
[0004] In order to have more information, researchers need to use an electron microscope (EM) which is capable of revealing image details up to a few nanometers (10 −9 m) in size. However, electron microscopes are incapable of presenting color images, as they use electrons and not photons. So, in order to visualize the antibody-antigen complex, researchers have to substitute the fluorescent marker, used in light microscopes by electron-dense particles. The most common of such electron-dense particles used are the gold particles. The fact that one needs to use electron-dense particles and observe a gray scale image in the EM can, however, become a problem, because the contrast of the gold particles is very close to that of the background structures. In other words, it becomes very difficult to identify the gold particles against a background that sometimes presents, for our eyes, almost the same gray values.
[0005] This problem is even more complicated, when one wants to observe multiple labeling. In the light microscope it is easy to identify different antibody-antigen complexes using fluorescent markers that display different colors. In the same image one can see very clearly the position of several of the fluorescent markers. This is not so easy to do in electron microscopy images. When working with gold particles, the researchers can use different particle sizes. It happens often that small particles form clusters which can be confused with a big particle by a human operator of the electron microscope. As one of the aims of the use of markers is to comparatively evaluate the number and positions of such elements in a multiple labeling experiment, the false identification or the lack of identification of particles will lead to completely wrong conclusions. A further complication is the necessity to use a higher magnification, in order to view the very small particles for example 3, 6, 10 nm in diameter, restricting the microscope field of view to very small regions of the sample.
[0006] These are the reasons why the researchers are looking for new methods and techniques that could permit a precise identification of particles over a large field of view. This possibility became real with the development of high-quality digital cameras, such as the slow-scan-cooled charge coupled device (CCD). With these new digital cameras it is possible to see in detail the microscopic images and to discriminate between very tiny contrast differences which had previously been impossible to observe. The development of digital microscopes allows the controlled movement of the field of view and the acquisition of image sequences in an oriented manner. These image sequences allow the creation of image montages that simultaneously offer an enlarged field of view and a high resolution.
[0007] Previous attempts have been made to establish automated methods of gold particle detection in electron microscopy. The prior art tools developed failed probably because they were not reliable and were incapable of multiple localization.
OBJECTS OF THE INVENTION
[0008] It is therefore an object of the present invention to provide researchers with an apparatus and method for the fast and reliable particle detection, counting and pseudo-color overlay.
[0009] A further object of the present invention is to provide a versatile module adapted to both single and double antigen detection of 3/10 nm, 6/15 nm and 10/25 nm gold particle pairs whereby the smaller particle type of every pair can be identified as both a singular particle and as a cluster of particles. A still further object of the present invention is to provide images as a montage to allow the analysis of particles in large field images.
DESCRIPTION OF THE FIGURES
[0010] FIG. 1 shows an overview of the electron microscope image capturing system of the invention.
[0011] FIG. 2 shows a flow diagram of sample preparation.
[0012] FIG. 3 shows a diagram of sample preparation.
[0013] FIG. 4 shows the construction of photo-montage.
[0014] FIG. 5 shows a further example of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention discloses a method and apparatus for double gold labeling and large field image. FIG. 1 shows an electron microscope LEO EM 912 Omega (LEO, Oberkochen, Germany) with the 2k−2k pixel array slow-scan cooled charge coupled device camera of Pro scan (SCC-CCD camera; supplied by Proscan Elektronische Systeme, Scheuring, Germany; abbreviated as “SSC-Camera” in FIG. 1 ). The electron microscope is used to obtain the images that are processed by the invention. The inventive module was embedded in the analysis 3.1 PRO software (SIS-Soft Imaging System, Münster, Germany) on the PC (Pentium III with 512 MB RAM). The use of the imaging equipment allows high-resolution, high-dynamic range images to be obtained that were aligned in order to produce wide-field presentations of specimen areas. After image acquisition and creation of the wide-field presentation, a user-controlled segmentation of gold particles and consequently separation from other specimen structures was performed. Following image binarization, identification and classification of the particle types is achieved through the comparison of shape and size by the inventive module according to the present invention. Afterwards, false colors were assigned to each particle group or size class.
[0016] The method described here presented several advantages. The high-dynamic range of the SSC CCD images allows the reliable separation of the gold particles from the background disregarding the contrast. Detection by means of the shape and size parameters and an evaluation for different gold particle pairs is possible using the present invention. The use of wide-field frames after multiple image alignment of high-magnification images enables the user to selectively show particle distributions in overview. Finally, the classification module allows the identification of particles that are either singular or clustered. By “clustered” is meant a very close association or agglomeration of single particles. This offers fast and reliable particle detection and evaluation of the results in research processes. An evaluation of particle distributions can be performed by the selection of a region of interest (ROI). Further, a visualization and evaluation of particle pairs in wide-field images is provided. Finally, an analysis of complete cell and tissue regions in immunocytochemical specimens at high spatial resolution becomes possible without the need for additional magnification processes.
[0017] Since gold particles or gold particle pairs of different sizes are very interesting for the purposes of microchip producing companies in their efforts to produce nanowires, it is possible that the present invention might be useful for applications in that field. In a field closer to immunocytochemistry, researchers presently working with in-situ hybridization and antigen localization mediated by antibody application or with microarrays for rapid screenings (and applying gold particles) could use the method as well. In general, the method according to the present invention helps to discriminate structures of a certain contrast and a defined size from a heterogeneous background, which, in part, exhibits comparable contrast to the target structure. The invention may be implemented as an add-on in an already existing software package. As a result the available software needs not to be changed completely but only be extended to include the modules according to the present invention.
[0018] Sample preparation for observation in the microscope will now be explained with reference to FIGS. 2 and 3 .
[0019] Preparation of microscopic sections.
[0020] Cells grown for 36 h were centrifuged (1500 rpm/10 min) and the pellet was directly fixed for 2 h at room temperature (or alternatively overnight at 4° C.) without washing, with a solution containing 0.1% glutaraldehyde (50% solution, grade 1; Sigma-Aldrich), 4% parafornaldehyde, 4% sucrose, 0.1% picric acid, 5 mM calcium chloride in PEM buffer (0.1 M Pipes, 2 mM EGTA, 1 mM MgSO4, pH 6.8 (Ogbadoyi et al., 2000)). After having been washed with PEM buffer, the cells were dehydrated in increasing concentrations of ethanol from 30% to 100% and embedded in the hydrophilic resin LR-White (hard grade; Agar Scientific, distributed by Plano, Wetzlar, Germany). The polymerization of LR-White blocks was performed for 48 h at 4 C under UV light irradiation. The sections (steps 300 , 310 ) were made using a Reichert-Jung Ultracut E (Leica Mikrosysteme, Bensheim, Germany) ultramicrotome and collected on nickel grids (step 210 ).
[0021] The antibodies used for immunolocalization are available from commercial sources. The primary antibodies were tested by fluorescence microscopy. These were: monoclonal anti-a-tubulin from mouse, clone B 5.1.2, IgG (Sigma-Aldrich, No. T5168) used at a dilution of 1:1000; and mouse anti-actin, clone JLA 20, IgM (Oncogene, Boston, MA, USA, No. CP01), used at a dilution of 1:100. The gold-conjugated secondary antibodies used were from Aurion (distributed by Biotrend, Cologne, Germany), with different particle sizes (in this case 6 and 15 mn): goat antimouse IgG (6-nm) and goat anti-mouse IgM (15 nm), both diluted 1:40. For the 10 nm/25 nm experiments the following conjugates were used: goat anti-mouse IgG/25-nm gold and goat anti-mouse IgM/10 nm (diluted 1:40). The immunolocalization procedure was done following directions from the supplier (Aurion), with some modifications. Briefly, the sections 310 were incubated with 50 mM glycine in PBS for 15 min and nonspecific binding was prevented by incubation in 5% bovine serum albumin (BSA) plus 1% normal goat serum (NGS) for 30 min. After being washed three times in BSA-c buffer (PBS, pH 7.4, p0:1% BSA-c; Aurion, distributed by Biotrend, Cologne, Germany), the sections 310 were incubated in the primary antibody (which contained a mixture of the two antibodies) for 1 to 2 h at room temperature (step 220 ) as can be seen in 320 . The sections 320 were then washed with BSA-c (3-10 min) and incubated with secondary antibodies (also a mixture of both gold conjugated particles, room temperature) for 1 h (step 230 ) as can be seen in 330 . After this incubation the sections 330 were washed thoroughly with BSA-c buffer. The sections (step 330 ) were contrasted with an aqueous solution (5%) of uranyl acetate for 10 min, after which the grids were washed by submerging them into distilled water. The use of lead citrate was omitted. The sample was then imaged using the electron microscope 340 with the slow-scan cooled charge coupled device camera of Proscan (SCC-CCD camera (step 240 )). Image acquisition and creation of the wide-field presentation was carried out in step 250 . A user-controlled segmentation 360 of gold particles and consequently separation from other specimen structures was performed (step 260 ). Following image binarization (step 260 ), identification and classification 370 of the particle types are achieved through the comparison of shape and size by the present invention (step 270 ). Afterwards, false colors were assigned to each particle group or size class (step 280 ) and added as an overlay 380 .
[0022] The software used to implement the invention is designed such that different windows open automatically once the previous step in the procedure was completed. The image processing will now be explained in more detail.
[0023] After the image has been acquired, the operator of the electron microscope selects a region of interest.
[0024] The image imperfections in the stored images of the selected region of interest such as uneven background are corrected by the subtraction of the original image from a background image which has been previously stored. This subtraction function uses two different reference images: a gain image and an offset image. The subtraction is carried out frame by frame. This function is to be found in the 3.1 PRO software package.
[0025] A step of improving the contrast is then carried out. This is done to ensure that the contrast and brightness of the original image is digitally increased. The stored images use a contrast histogram which is “stretched”. This function is available in the 3.1 PRO software package.
[0026] The operator can now interactively identify the range of gray scales that represents the objects of interest (i.e. the gold particle) and separates them from other background structures. The input image represents 2 14 (14 bit) gray scales. The operator must teach the computer which gray scales represent the contrast of the gold particles. In order to do this, it is necessary to adjust the lower and the upper threshold values of the histogram to obtain a contrast window. With the use of a contrast window, the operator can teach the computer in what range of gray values the gold particles are included. The threshold window represents a histogram with all the gray values of an image and two vertical lines representing the upper and the lower threshold value of the grey value which limit the contrast window chosen by the operator to identify the gold particles.
[0027] It is possible on a computer screen to follow the changes in the definition of the contrast window performed by the operator. The computer creates a binary image displayed on the computer screen in which the objects of interest (gold particles) having contrast values between the threshold values will be assigned white values and the background or the other objects not of interest (i.e. not gold particles) a black value.
[0028] The original image is thus segmented into two parts: the objects of interest that appear white in the resultant image and the background and the other objects appear in black. The operator can move the contrast window and watch the target structures in the images appearing in white or vanishing, depending on the selected threshold values. When the window is set such that only the target structures (gold particles) are visible as white dots, the segmentation was complete and the subsequent steps carried out. This segmentation is necessary to ensure reliable evaluation of gold particle detection and counting. The segmentation step is provided by analysis 3.1 PRO software package (SIS-Soft Imaging System, Münster, Germany) and is shown as block 360 in FIG. 3 .
[0029] The shape of the particle is now defined. This is done using the following definition of the ratio of the maximum measured diameter of the particle to the minimum measured diameter.
[0030] Sphere=Maximum diameter/minimum diameter>=0.7
[0031] Clusters=Maximum diameter/minimum diameter<0.7
[0032] In this step the computer will analyze the shape of the particles. Gold particles are usually produced with a shape substantially close to a sphere; the isolated gold particles will present a ratio of their largest to the smallest diameter of approximately 1. The particle clusters will display irregular shapes.
[0033] A step of identifying the size of the particle is then carried out. This will be explained by reference to an example working with 6 and 15 nm particle pairs.
[0034] The surface area of particles that have to be identified as gold particles by the method has to be defined. According to measurements performed prior to the invention, the limits of cross-section areas of particles for this example could be set to be
[0000] Small particles (6 nm):10 nm 2 <Area<60 nm 2
[0035] Big particles (15 nm):40 nm 2 <Area<90 nm 2
TABLE 1 shows a particle classification scheme developed for this example: Class Area Correction Type Size* Shape** Factor (CF) Result Label Class 1 10 < Shape > 1 NX1 Particle size ≦ 60 0.7 Type 1 Small Class 2 40 < Shape < 2 NX2 Particle size ≦ 90 0.7 Type 1 Small Class Increment Shape < 3-20 NXCF 3-20 Particle 3-20 of 50 nm 0.7 Type 1 Small Class 90 < size Shape > 1 NX1 Particle 21 0.7 Type 2 Big The final number of classes depends on the number of particle clusters. *The Area size means cross-section area of particles and is given in nm 2 . The microscope system must be well calibrated. **The object shape was calculated according to the following formula: 4π (area/perimeter 2 ); CF 3-20 = Correction factor of classes 3-20; N = number of objects encountered.
[0036] As a single particle or example of 6 nm diameter could have cross-sectioned area ranging from 10 to 60 nm 2 a range of classes was established using an increment of 50 nm 2 in each different class, beginning with 40 nm 2 . If a specific object presents an area of 45 nm 2 , it could be one single particle or a cluster of two small single particles. The method will correctly identify the object based on the shape.
[0037] These classifications are necessary because particles are produced in fact with a range of sizes near the assigned diameter, but with differences, as shown in defined Table 1 . The whole range of particles is grouped according to this classification defined in the Table 1 . This classification is necessary because the gold particles, especially the small ones, were not always placed as singular particles on the sample section but could be located in such a close association to one or more neighbors of gold particles that a cluster of small particles with a gold particle—like contrast but without the sphere—like shape was found. In order not to omit these and to be able to count the number of gold particles in such a cluster, the method had to be designed in such a way that these clusters could be divided up into the single particles that would be otherwise hidden in the cluster. This was again done by defining the different cross-section areas that cover a group of 2 (class 2), 3 (class 3) or more small gold particles. At the same time the shape parameter had to be defined to be different from the shape parameter of single small gold particle because the overall shape of a cluster of small particles could not be sphere-like. Therefore the definition of the shape parameter had to change from class 1 to class 2 and all the higher classes (shape>0.7 in class 1; shape<0.7; see Table 1 ).
[0038] In the last step the method discriminates the small particles, either as single particles or as a cluster of small particles, from the large particles. The large particles in the same specimens were observed not to cluster with each other. Therefore, in this case, it was sufficient to identify the large particles according to their cross-sectional area and having their shape close to a sphere (class 21). The number of classes, 21 in this case for the differentiation of 6 and 15 nm particles, was decided according to the observations and experience that were made during the handling of the gold particles. It was sufficient in this example for the differentiation of this pair of gold particles ( 6/15 nm) to define 21 classes of particles using the parameters as explained above.
[0039] After the identification of the particles and separation of the single particles from the clusters of small particles, and small particles from big particles, the system is able to count the total number of particles in a predetermined area. This is done by defining a correction factor for each class that was not identifying single particles. The correction factor had to be defined because the cluster of particles (i.e. classes 2 to 20) creating an area with a gold-like contrast but with irregular shape was initially identified as a single area. The correction had to be made because in the area of irregular shape a certain number of gold particles would be hidden. The number of the hidden gold particles depends on the size of the cross-section area. The total number of particles is therefore given below:
N T =NS+N C2−20 X CF 2−20
N T =Total number of particles
N S =Total number of single particles
N C2−20 =Total number of clusters from classes 2 to 20
CF 2−20 =Correction factors applied to corresponding cluster classes
CF 2−20 =Correction factor for cluster evaluation
[0040] The particles separated by the method described are colorized and a final image with the original frame plus colorized particles is displayed to the operator on the computer screen as shown in block 380 on FIG. 3 . A different color is used for the different particle sizes. The false colors are assigned to specific gray scale values by the image processing software. These colors are overlaid over the particles in a graphic plane and are not added permanently to the image. This result is the colorization of the particles from the gray scale image.
[0041] The number of single and cluster particle of a specific size can be summarized in the defined region of interest. In other words, depending on the region of interest selected, the system will display the total number of particles of different sizes, as well as the number of single particles and the number of cluster particles observed in the region of interest. The total number of particles in a cluster will be defined by the total area of the cluster divided by the single area of the particle, as described below.
Total Number of Particles = The Area of the Cluster The Area of a Single Particle
[0042] FIG. 4 shows a further embodiment of the invention which allows the composition of a wide-field image 420 from a plurality of single, highly magnified electron microscopic images 410 adjacent to each other as a photo-montage. The option to perform image montages is a function of the software analysis package 3.1 PRO. The same particle analysis as described above resulting in a false color overlay view can be carried out. The composed image 420 still has the quality and the spatial resolution of the original images 420 .
[0043] The invention was designed to count and overlay particle pairs of different sizes depending on the type of double labeling experiment performed. The invention has been described with respect to particles of sizes 6 nm and 15 mn, but could also be used with 3/10 nm, and 10/25 nm particle size pairs. The difference in size between the particles belonging to a labeling pair should be at least above 100%. This is due to a greater variability in the sizes of the colloidal gold particles. As can be seen from Table 1 , the area of a single small particle of a mean diameter of 6 nm can indeed extend from 10 to 60 nm 2 . A similar variability in size can be found for larger particles. The single particles were identified by the computer taking into account both size and shape.
[0044] Furthermore in the illustrated example, one particle with 30 nm 2 area and with a spherical or almost spherical shape will be classified by the method as a single small particle, whereas a particle of 120 nm 2 area and round shape will be identified as a big single particle. If, in this example, an object covers an area of 90 nm 2 and exhibits an irregular shape after the segmentation step, the computer will identify this element as a cluster of particles and assign it to the object class 2.
[0045] Should two particles be clustered together, the shape will not be spherical and the object will be identified as being composed of two small particles.
[0046] The invention also works with only one type of label in a specimen. Therefore the method is also useful for single label detection on the basis of gold particles.
[0047] The invention can also be used for any automatic label structure detection in electron microscopy. This includes wide-field detection of elemental markers that are useful for labeling on the basis of energy-filtering transmission electron microscopy (EFTEM). EFTEM allows the selective presentation of certain chemical elements in specimens. If labels are available that are designed like gold particles (spherical) and are composed of a defined chemical element, these labels can be separated and selectively displayed by the method presented here, comparable to what was described here for gold particle detection.
EXAMPLE
[0048] For the sake of clarity the invention was described herein using a single sample image. The following FIG. 5 . 1 to 5 . 6 display an actual example of the invention in which the image montage on the computer screen is constructed.
[0049] FIG. 5 . 1 shows the invention having three options. Processing the image from an image store or gallery (labeled G), acquiring the image from the microscope (L) or first creating a montage (M) of several images and then proceeding with the analysis.
[0050] FIG. 5 . 2 shows the first step within the montage option, the acquisition and alignment of several high resolution (2048 square pixel size) and high dynamic range (14 bit) images.
[0051] In FIG. 5 . 3 , after the automatic conclusion of the montage, the method allows the operator to define one region of interest (ROI—defined by a frame). In this example the whole image is selected.
[0052] In FIG. 5 . 4 the contrast window is established. The thin line in the contrast window should only reach the beginning of the histogram in the image, i.e. the initial planar region (left part in the contrast window, at the crossing point to the left black peak).
[0053] FIG. 5 . 5 shows the selection of the particle size and the classification mode. In this step the operator decides the size of the particle pair used ( 3/10 nm, 6/15 nm or 6/25 nm) and a if the detection will be limited to single particles or to single cluster particle detection. In the latter case, the computer will estimate the number of particles belonging to a cluster depending on the total cluster area.
[0054] In FIG. 5 . 6 , the number of particles is counted and an overlay image created. | The invention relates to a transmission electron microscope equipped with a 2k−2k pixel area Slow Scan Cooled Charge Coupled Device Camera connected to an image processing software for generating an image of a sample. A segmentation of gold particles in the sample is achieved by the separation from specimen structure and background noise. An identification and classification of particle types is carried out according to the shape and size of the detected particles or particle pairs and finally, the gold particle distribution is visualized by the generation of false color overlay images as well as the indication of the numbers in the image. | 6 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to amorphous metallic alloys, commonly referred to as metallic glasses, which are mostly formed by solidification of alloy melts by cooling the alloy to a temperature below its glass transition temperature before appreciable crystallization or nucleation of crystals can occur.
[0002] Metallic alloys having an amorphous or glassy phase are useful for several industrial applications. Normally, metals and intermetallic alloys crystallize during solidification from the liquid phase. Some metals and intermetallic alloys may be undercooled and remain as a viscous liquid phase or amorphous phase or glass at ambient temperatures when cooled rapidly. Typical cooling rates are about 1,000 to 1,000,000° K/sec.
[0003] To achieve rapid cooling rates of 10,000° K/sec or greater, a very thin layer (e.g., less than 100 micrometers) or small droplets of molten metal are brought into contact with a conductive substrate maintained at near ambient temperature. The small dimension of the amorphous material is a consequence of the need to extract heat at a sufficient rate to suppress crystallization. Thus, previously developed amorphous alloys have only been available as thin ribbons or sheets or as powders. Such ribbons, sheets or powders may be made by melt-spinning onto a cooled substrate, such as a spinning copper wheel, or by thin layer casting on a cooled substrate moving past a narrow nozzle.
[0004] Many efforts have been directed to searching for amorphous alloys with greater resistance to crystallization for achieving lower cooling rates and hence thicker metallic glasses, often also called bulk metallic glasses. The further crystallization may be suppressed at lower cooling rates, and thicker bodies of amorphous alloys may be obtained.
[0005] During formation of amorphous metallic alloys, undercooled alloy melt may crystallize.
[0006] Crystallization occurs by a process of nucleation and growth of crystals driven by the energetically optimum structure and thereby setting the crystallization energy free. To form an amorphous solid intermetallic alloy, the melt has to be cooled from or above the melting temperature (Tm) to below the glass transition temperature (Tg), without the occurrence or with only minor occurrence of crystallization. Tx is the temperature at which crystallization occurs upon heating the amorphous alloy above the glass transition temperature. Crystallization of the metallic glass occurs at temperatures below crystallization temperature Tx but at a lower rate. The crystallization temperature Tx is not a sharply defined first order phase transition.
[0007] The metallic glasses are brought into the desired form by heating the metallic glass to a temperature above the glass transition temperature Tg and then forming the metallic glass. For forming the metallic glass, it is therefore desirable to find a system where the difference DT between the glass transition temperature Tg and the crystallization temperature Tx is substantial. A substantial difference in temperature DT allows the metallic glass to be formed without crystallization or, more precisely, without creating high amounts of unwanted crystalline phase in the metallic glass.
[0008] For bulk metallic glasses, it is therefore desirable to use an alloy having a substantial temperature difference (DT) between the crystallization temperature (Tx) and the glass transition temperature (Tg).
[0009] Intermetallic alloys that form bulk metallic glasses include zirconium-based alloys. One group of such Zr-based alloys is the Zr—Ti/Nb—Cu—Ni—Al alloys, which are known for example from X. H. Lin et al., “Effect of Oxygen Impurity on Crystallization of an Undercooled Bulk Glass Forming Zr—Ti—Cu—Ni—Al Alloy,” Materials Transactions, Vol. 38, No. 5 (1997), pages 473 to 477; U.S. Pat. No. 5,735,975; U.S. Patent Application Publication 2004/238,077; European Patent Application Publication EP 2 597 166 A1; X. Zeng et al., “Influence of melt temperature on the compressive plasticity of a Zr—Cu—Ni—Al—Nb bulk metallic glass,” Journal of Materials Science 46 (2011), pages 951-956; Z. Evenson et al., “High temperature melt viscosity and fragile to strong transition in Zr—Cu—Ni—Al—Nb(Ti) and Cu 47 Ti 34 Zr 11 Ni 8 bulk metallic glasses,” Acta Materialia 60 (2012), pages 4712 to 4719; Y. F. Sun et al., “Effect of Nb content on the microstructure and mechanical properties of Zr—Cu—Ni—Al—Nb glass forming alloys,” Journal of Alloys and Compounds 403 (2005), pages 239-244.
[0010] Another group of Zr-base alloys forming bulk metallic glasses is the Zr—Ti—Nb—Cu—Ni—Be alloy known for example from C. Hays et al., “Improved mechanical behavior of bulk metallic glasses containing in situ formed ductile phase dendrite dispersions,” Materials Science and Engineering: A, Volumes 304-306, (2001), pages 650-655; or F. Szuecs et al., “Mechanical properties of Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 ductile phase reinforced bulk metallic glass composite,” Acta Materialia, Volume 49, Issue 9, (2001), pages 1507-1513. A further group of Zr-based alloys forming bulk metallic glasses and bearing beryllium is Zr—Ti—Cu—Ni—Be, known from U.S. Pat. No. 5,288,344 and U.S. Pat. No. 5,368,659.
[0011] In some of the above mentioned systems, the temperature difference DT between the crystallization temperature Tx and the glass transition temperature Tg is less than 70° K, causing difficulties when forming these metallic glasses. A further drawback of some metallic glasses may be found in the difficulties to obtain the metallic glass from the melt. When the melting temperature Tm of the alloy is high compared to the glass transition temperature Tg, a higher amount of energy has to be extracted from the alloy to create the metallic glass. If the activation energy to form crystal nuclei in the alloy is low, seed crystals will form during the cooling of the alloy. Both problems may be encountered with a higher cooling rate. As thermal energy has to be conducted from the cooling metal alloy melt, a higher cooling rate results in unfavorably thinner metallic glass samples. The obtainable critical thickness of about 5 mm is still not sufficient for many technical applications, e.g., parts of clocks, springs, elastic contacts for electronic devices, etc.
BRIEF SUMMARY OF THE INVENTION
[0012] A task of this invention particularly is to overcome these problems. Even though some of the above mentioned metallic glasses show a rather high temperature difference DT of up to 100° K between the crystallization temperature Tx and the glass transition temperature Tg, there is the need and wish to get to even higher temperature differences DT to make thermoplastic forming of the bulk metallic glass even easier. Furthermore, it is desirable to find a mixture of chemical elements, wherein the melting temperature Tm is low and close to the glass transition temperature and wherein the activation energy to form crystal nuclei is as high as possible. It is a further task of the invention to obtain semifinished products having a thickness above 5 mm.
[0013] The invention provides a class of alloys that form metallic glass upon cooling to below the glass transition temperature Tg at a rate of 100° K/sec or lower and having a DT value of at least 70° K. Such alloys comprise zirconium in the range of 70 to 80 weight percent, beryllium in the range of 0.8 to 5 weight percent, copper in the range of 1 to 15 weight percent, nickel in the range of 1 to 15 weight percent, aluminum in the range of 1 to 5 weight percent, and niobium in the range of 0.5 to 3 weight percent, or narrower ranges depending on other alloying elements and the critical cooling rate and value of DT desired.
[0014] The compositions of the alloys may comprise inevitable trace impurities which are not considered. Other elements in the metallic glass are, preferably, less than two weight percent.
[0015] The composition of the intermetallic alloy according to the invention may be solidified with relatively low cooling rates of 100° K/sec or lower and create a metallic glass, which can easily be formed above the glass transition temperature Tg, because the crystallization temperature Tx is at least 70° K higher than the glass transition temperature Tg without creating more than 50% by volume (vol %) of crystalline phase in the metallic glass.
[0016] The mixtures of large atoms or ions, such as zirconium and niobium, medium sized atoms or ions, such as copper or nickel, and small atoms or ions, such as beryllium, prevent the melt from establishing a short range order easily. Therefore, the intermetallic alloys according to the invention have a higher activation potential to create crystal seeds or nuclei. Because of this, the intermetallic alloy may be cooled at lower cooling rates without formation of greater than 50 vol % crystalline phase and/or crystalline seeds in the metallic glass. This results in the possibility to prepare thicker samples of the intermetallic glass.
[0017] Aluminum binds oxygen from the melt, which otherwise serves as a seed for crystal formation. Therefore, the aluminum works as an oxygen getter, which further reduces the formation of crystalline phases in the metallic glass and thereby improves the obtainable thickness of the bulk metallic glass product.
[0018] These and other features and advantages of the invention will be appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying tables.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The tasks of the invention are solved by a metallic glass formed of a zirconium-based alloy having about a Zr, b Be, c Cu, d Ni, e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
[0020] a is in the range of 70 wt % to 80 wt %,
[0021] b is in the range of 0.8 wt % to 5 wt %,
[0022] c is in the range of 1 wt % to 15 wt %,
[0023] d is in the range of 1 wt % to 15 wt %,
[0024] e is in the range of 1 wt % to 5 wt %, and
[0025] f is in the range of 0.5 wt % to 3 wt %.
[0026] The tasks of the invention are also solved by a metallic glass formed of a zirconium-based alloy having about a Zr, b Be, c (Cu x Ni 1-x ), e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
[0027] a is in the range of 70 wt % to 80 wt %,
[0028] b is in the range of 0.8 wt % to 5 wt %,
[0029] c is in the range of 10 wt % to 25 wt %,
[0030] e is in the range of 1 wt % to 5 wt %,
[0031] f is in the range of 0.5 wt % to 3 wt %, and
[0032] x is an atomic fraction and in the range of 0.1 to 0.9.
[0033] In one embodiment of the invention, a is in the range of 74 wt % to 78 wt %. This composition range leads to the best results concerning DT.
[0034] More precisely, the tasks of the invention are solved by a metallic glass formed of a zirconium-based alloy having about a Zr, b Be, c Cu, d Ni, e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
[0035] a is in the range of 74 wt % to 76 wt %,
[0036] b is in the range of 1 wt % to 3 wt %,
[0037] c is in the range of 9 wt % to 12 wt %,
[0038] d is in the range of 6 wt % to 8 wt %,
[0039] e is in the range of 2 wt % to 4 wt % and
[0040] f is in the range of 1 wt % to 2 wt %.
[0041] For all these metallic glass alloys, the temperature difference DT between the crystallization temperature Tx and the glass transition temperature Tg of the metallic glass is greater than 70° K, preferably greater than 100° K, and more preferably greater than 120° K.
[0042] Further, in one embodiment, a part of the Nb is substituted by Ti. In this case, the metallic glass has 0.5 wt % to 3 wt % (Nb y Ti 1-y ), wherein y is an atomic fraction in the range of 0.1 to 1.
[0043] The tasks of the invention are also solved by a method for making a metallic glass product having at least 50 vol % amorphous phase comprising the steps of:
[0044] forming a melt of an alloy having the formula: a Zr, b Be, c Cu, d Ni, e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
a is in the range of 70 wt % to 80 wt %, b is in the range of 0.8 wt % to 5 wt %, c is in the range of 6 wt % to 15 wt %, d is in the range of 4 wt % to 10 wt %, e is in the range of 1 wt % to 5 wt %, and f is in the range of 1 wt % to 3 wt %, and
[0051] cooling the melt to a temperature below its glass transition temperature at a sufficient cooling rate to prevent formation of more than 50 vol % crystalline phase in the product.
[0052] The tasks of the invention are further solved by a method for making a metallic glass product having at least 50 vol % amorphous phase comprising the steps of:
[0053] forming a melt of an alloy having the formula a Zr, b Be, c (Cu x Ni 1-x ), e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
a is in the range of 70 wt % to 80 wt %, b is in the range of 0.8 wt % to 5 wt %, c is in the range of 10 wt % to 25 wt %, e is in the range of 1 wt % to 5 wt %, f is in the range of 0.5 wt % to 3 wt %, and x is an atomic fraction and in the range of 0.1 to 0.9, and
[0060] cooling the melt to a temperature below its glass transition temperature at a sufficient cooling rate to prevent formation of more than 50 vol % crystalline phase in the product.
[0061] The tasks of the invention are also solved by a method for making a metallic glass product having at least 50 vol % amorphous phase comprising the steps of:
[0062] forming a melt of an alloy having the formula a Zr, b Be, c Cu, d Ni, e Al, and f Nb, where a, b, c, d, e, and f are weight percentages wherein:
a is in the range of 74 wt % to 76 wt %, b is in the range of 1 wt % to 3 wt %, c is in the range of 9 wt % to 12 wt %, d is in the range of 6 wt % to 8 wt %, e is in the range of 2 wt % to 4 wt %, and f is in the range of 1 wt % to 2 wt %, and
[0069] cooling the melt to a temperature below its glass transition temperature at a sufficient cooling rate to prevent formation of more than 50 vol % crystalline phase in the product.
[0070] In one embodiment of the method, the cooling rate is 100° K/sec or lower and preferably 10° K/sec or lower.
[0071] Additionally or alternatively, the thickness of the prepared metallic glass product may be between 8 mm and 20 mm.
[0072] The metallic glass is thermoplastically formed by heating the obtained metallic glass to above the glass transition temperature Tg but below the crystallization temperature Tx, forming the obtained metallic glass to a desired shape or product, and cooling the formed metallic glass to below the glass transition temperature Tg. It is preferred that the obtained metallic glass be heated to 1° K to 30° K above the glass transition temperature Tg prior to the thermoplastic forming.
[0073] For purposes of this invention, a metallic glass product is defined as a material that contains at least 50 vol % of the glassy or amorphous phase. To obtain the bulk metallic glasses of zirconium-based alloys at cooling rates of 100° K/sec or lower, the intermetallic melt is cast into cooled metal molds, preferably copper molds. As a result, rods or plates of up to 20 mm wall thickness are obtained. Alternatively, the melt may also be cast in silica or other glass containers.
[0074] A variety of new glass-forming intermetallic alloys have been identified to practice this invention. The ranges of alloys suitable for forming amorphous metal alloys may be defined in various ways. Some of the composition ranges are formed into metallic glasses with relatively higher cooling rates, whereas preferred compositions form metallic glasses with appreciably lower cooling rates.
[0075] The following is a table of alloys that can be cast as a rod at least ten millimeters thick, of which some have at least about 50 vol % amorphous phase. The exact quantity of the amorphous phase in the rod is difficult to measure. Hence, only three different quantities of amorphous phase in the sample rod are distinguished—about 100 vol % are of amorphous phase, at least about 50 vol % are of amorphous phase and no (0%) or clearly less than 50 vol % amorphous phase could be found in the amorphous phase of the sample rod. The amount of amorphous phase is determined by thermal analysis. The amount of amorphous phase may be calculated from the amount of exothermic energy when the complete amorphous phase is crystallized. The energy can be measured by differential scanning calorimetry (DSC) or differential thermal analysis (DTA). Furthermore or alternatively, the amount may be determined by a x-ray diffraction method or structural analysis.
[0000]
Be
Al
Cu
Ni
Nb
Zr
Amorphous
(wt %)
(wt %)
(wt %)
(wt %)
(wt %)
(wt %)
phase (vol %)
3.32
3.14
9.84
7.29
1.45
74.97
100%
3.32
3.11
9.77
7.25
1.45
75.11
100%
3.29
3.04
9.51
7.01
1.52
75.63
100%
3.29
3.03
9.54
7.03
1.51
75.61
100%
0.00
6.32
9.57
7.00
1.54
75.58
0%
0.00
6.31
9.58
7.01
1.55
75.55
0%
1.06
3.13
11.33
7.06
1.56
75.86
50%
1.05
3.14
11.23
7.05
1.60
75.94
50%
0.00
3.09
12.82
7.02
1.51
75.56
0%
0.00
3.05
12.84
7.08
1.48
75.55
0%
3.35
0
12.22
7.15
1.55
75.62
0%
1.80
3.14
9.41
7.10
3.01
75.54
0%
1.80
3.13
9.40
7.11
3.02
75.54
0%
[0076] The values of Tg and Tx are measured by differential scanning calorimetry (DSC), but may also be determined by differential thermal analysis (DTA). A higher DT allows for a lower minimum cooling rate for obtaining an amorphous alloy and for a longer time available for processing (thermoplastic forming) the amorphous alloy above the glass transition temperature. A DT of more than 100° K indicates a particularly desirable glass-forming alloy.
[0077] The positively tested alloys have at least 50 vol % amorphous phase, and preferably about 100 vol % amorphous phase. The glass transition temperature Tg is about 380° C. while the crystallization temperature Tx is about 510° C. for the alloys with about 100 vol % amorphous phase. Therefore, DT is about 130° K or even slightly more, which is clearly greater than the DT of other zirconium-based metallic glasses known in the art.
[0078] A further advantage of the positively tested alloys is the thickness with which the metallic glass may be produced. The metallic glass containing at least 50 vol % or about 100 vol % amorphous phase may be produced with a thickness of up to 20 millimeters.
[0079] A number of specific examples of glass-forming alloy compositions having a wide temperature range of amorphous solidification are described herein. It will be apparent to those skilled in the art that the boundaries of these regions described are approximate, that compositions somewhat outside these precise boundaries may be good glass-forming materials, and that compositions slightly inside these boundaries may not be glass-forming materials at cooling rates that are too low. Thus, within the scope of the following claims, this invention may be practiced with some variation from the precise compositions described. | A class of alloys is provided that form metallic glass upon cooling below the glass transition temperature Tg at a rate below 100° K/sec. The alloys have a high value of temperature difference (DT) between the crystallization temperature (Tx) and the glass transition temperature (Tg) of the intermetallic alloy. Such alloys comprise zirconium in the range of 70 to 80 weight percent, beryllium in the range of 0.8 to 5 weight percent, copper in the range of 1 to 15 weight percent, nickel in the range of 1 to 15 weight percent, aluminum in the range of 1 to 5 weight percent and niobium in the range of 0.5 to 3 weight percent, or narrower ranges depending on other alloying elements and the critical cooling rate and value of DT desired. Furthermore, methods are provided for making such metallic glasses. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to mine roof support systems and more particularly, it concerns improvements in mine roof support systems of the type including a plurality of telescopically interconnected support units arranged to provide transverse parallel lines of roof support over a work area and capable of being self-advanced during mining operations.
As exemplified in U.S. Pat. No. 2,795,935-Fitzgerald, No. 2,795,936-Blower et al and No. 4,143,991-Stafford, mine roof support systems are known to be available for continuous mining operations in which a plurality of inverted U-shaped units are capable of self-advancement with mining operations to protect the working area between the mining face and the area under a roof which has been permanently reinforced such as by timber and/or roof bolting. In contradistinction to well-known roof jacks used in long-wall mining operations, the units of the systems disclosed in these patents are arranged in tandem and each include a transverse beam or truss supported at opposite ends by a pair of extensible props so that the units lie perpendicular to the direction of advance rather than parallel to the direction of advance as in the case of long-wall jacks. In a manner common to most self-advancing roof support systems used in mining operations, these systems employ telescopic struts between successive units so that as one unit is retracted away from the mine roof, it may be pushed or pulled by extension or contraction of the struts reacting with another unit which is fixed as a result of it being forcibly retained between the mine floor and the mine roof.
To facilitate an understanding of component orientation in mine roof support systems of the type under discussion, the term "unit plane" will be used hereinafter to designate a plane containing the central axes of the transverse roof engaging beam and of the extensible props supporting opposite ends of the beam for each inverted U-shaped unit of the system. In light of basic system geometry, therefore, each unit plane will be generally vertical and perpendicular to the direction of system advance with mining operations as well as generally perpendicular to the struts extending between and interconnecting successive units of the system. Also, it will be appreciated that maximum roof support capability will be obtained when the unit plane and the axes of both unit props in that plane are truely vertical irrespective of undulations in the mine floor or roof, relative inclination of the mine floor or roof in the unit plane and the like.
Maximum roof supporting capacity has been achieved in such systems by appropriate pivotal interconnection of the props with the beams in each unit as well as of the struts with the props between successive units. To retain each unit in an essentially erect condition when the beam thereof is retracted away from the roof for longitudinal advance of the unit, however, provision must be made for stabilizing the pivotal connection of components. For example, the props and beam of each unit must be restored and retained in an essentially perpendicular relationship and also the connection of the longitudinal struts with the props of a retracted unit must be maintained near perpendicular to assure that the unit plane of a unit being advanced relative to another unit will remain essentially vertical while at the same time accommodate undulations in the mine floor. In the past, these requirements have involved design compromise between structural integrity and ruggedness required by the mining environment on the one hand and, on the other hand, a kind of simplicity important to such factors as cost and weight reduction as well as efficient and safe mining conditions which necessitate a minimum of interference by the support system with maneuverability of mining equipment and personnel.
SUMMARY OF THE INVENTION
In accordance with the present invention, an improved stabilizing arrangement and structure is provided for mine roof support system of the type including a series of support units interconnected by extensible struts and each having a transverse beam supported at opposite ends by extensible props. The connection of each prop to the beam of a unit is through a coupling sleeve and spherical bearing pad to permit at least limited pivotal movement of the prop and beam in all directions. A stabilizing bracket extends between the upper end of each prop and the beam to impose a yieldable bias on this connection so that in the absence of a roof supporting load on each unit, the props and beam will be retained in a true perpendicular orientation in relation to each other.
The struts interconnecting successive units of the system are established by a pair of telescopic, hydraulically actuated, piston/cylinder assemblies. The opposite ends of each strut thus constituted are pivotally connected to the props of successive units by a loose clevis-type coupling to permit unrestricted pivotal movement on a vertical axis and limited movement about a horizontal coupling axis. A vertical prop engaging bracket is secured at at least one end of each strut and positively restricts pivotal movement of the prop, and thus of the unit plane containing the prop, to limited angular movement with respect to the strut. In this way, each support unit is maintained in a generally vertical unit plane while at the same time permitted limited canting movement at the strut connection. Accordingly, successive support units may move up and down in relation to each other as a result of undulations in the mine floor over which each unit is advanced by telescopic actuation of the struts.
Among the objects of the present invention are, therefore: the provision of an improved self-advancing mine roof support system of the type in which a series of inverted U-shaped supporting units are sequentially advanced by telescopic actuation of struts interconnecting the respective units; the provision of an improved stabilized pivotal connection of load bearing components of such a system; the provision of such a system which is adaptable to diverse heights of mine roofs; and the provision of an improved bracket structure for maintaining a generally vertical orientation of each support unit during advancing movement thereof.
Other objects and further scope of applicability will become apparent from the detailed description to follow taken in conjunction with the accompanying drawings in which like parts are designated by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation illustrating the mine roof support system of the invention;
FIG. 2 is an enlarged fragmentary elevation similar to FIG. 1.
FIG. 3 is an enlarged fragmentary cross-section on line 3--3 of FIG. 2;
FIG. 4 is a front elevation of the system illustrated in FIGS. 1 and 2;
FIG. 5 is a perspective view of a stabilizing bracket structure incorporated in the invention;
FIG. 6 is a fragmentary cross-section illustrating details of the beam and prop connection of the invention; and
FIG. 7 is a fragmentary cross-section similar to FIG. 6 but illustrating a modified embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1, 2 and 4 of the drawings, the mine roof supporting system of the present invention is shown to include a plurality of roof supporting units 10a-10g in position on a mine floor F to support a mine roof R. In FIG. 1, seven such units are illustrated though it will be understood that in practice, the specific number of units 10 may vary in number from two to seven or more without departure from the basic system concept. Each unit 10 may be considered as lying in a unit plane P which, as shown, is generally vertical and transverse to the direction of mining operation and to the direction of system advance. For purposes of orientation, it may be assumed that the direction of system advance is from left to right in FIG. 1 as depicted by the arrow A. In this respect also, however, the particular direction of system advance is not critical.
As shown most clearly in FIGS. 2 and 4, each of the units 10 include a horizontal roof supporting beam 12 which in the disclosed embodiment, is a tubular box-beam having top, bottom and side webs 14, 16 and 18, respectively, joined to provide a rectangular cross-section. Opposite ends of the beam 12 are supported by a pair of props, each designated generally by the reference numeral 20. All of the props 20 are of identical construction and as such, each includes a mine floor engaging shoe 22 and a telescopically extensible hydraulic jack defined by a cylinder 24 and a vertically moving piston rod 26. The lower end of each cylinder 24 is pivotally connected to the shoe 22 through a clevis connection 28 including a pin 30 lying on an axis parallel to the unit plane P and, as such, perpendicular to the direction of system advance. A pair of ears 32 secured to the shoe 22 and forming part of the clevis connection 28, extend from the shoe 22 up to the base of the cylinder 24 so that compressive loading between the base or lower end of the cylinder 24 and the shoe 22 will be borne by the ears 32 as distinguished from the pin 30. Also it will be seen that the configuraion of the shoe 22 enables it to be advanced in the manner of a skid over the mine floor F.
As shown most clearly in FIGS. 4 and 6 of the drawings, the upper end of each prop 20 is connected to one or the other of the opposite ends of the beam 12 by an assembly including a coupling sleeve 34. The lower end portion of the coupling sleeve overlaps the upper end of the piston rod 26 and contains a bearing pad or plate 36 to receive the lower spherical end 40 of a depending bearing post 42 secured rigidly to the beam 12 such as by welding to the top and bottom webs 14 and 16 thereof as shown in FIG. 6. Because the bearing pad 36 extends between the upper end of the piston rod 26 and the lower end 40 of the depending bearing post 42, it will be appreciated that the coupling sleeve 34 carries little or none of the compressive loading which, in practice, will be transmitted from the beam 12 to the piston rod 26 and the prop 20 in general. The sleeve 34 does, however, retain the connection between the beam 12 and the upper end of each prop as a result of upper and lower coupling pins 44 and 46, respectively. As shown in FIG. 6, the upper pin 44 extends through appropriate apertures in the sleeve 34 as well as through an oppositely tapered bore 48 in the post 42 so that it will not impede swiveling movement of the post 42 in the pad 36 at least within the design limits of the beam/prop connection.
To retain the beam 12 and the props 20 of each unit 10 normally in a mutually perpendicular orientation, a stabilizing bracket, generally designated by the reference numeral 50, extends between the coupling sleeve 34 of each prop 20 and the underside of the beam 12. As shown most clearly in FIG. 5, the stabilizing bracket includes a semi-cylindrical mount 52 adapted to be nested against the exterior of the coupling sleeve 34. The mount 52 includes a pair of diametrically opposite openings 54 through which the pin 46 extends. By reference to FIGS. 2 and 6, it will be seen, therefore, that the pin 46 extends through the openings 54, through aligned openings in the coupling sleeve 34 and through the upper end portion of the piston rod 26. The bracket 50 further includes a pair of upwardly extending trapezoidal gusset plates 56 and 58 welded at their lower ends to the semicylindrical mount 52 and joined at their upper ends by an abutment plate 60. As shown in the drawings, the plane of the abutment plate 60 lies perpendicular to the axis of the semicylindrical mount 52 and thus perpendicular to the axis of each prop 20. A tension spring 62 extends from a plate 64 secured such as by welding between the gusset plates 56 and 58, and a bale 66 secured to the lower web 16 of the beam 12.
The stabilizing brackets 50 as thus constructed, each provide a rigid angular member with mutually perpendicular abutment surfaces defined, respectively, by the internal nesting surface of the mount 52 and the upper planar surface of the abutment plate 60. In the system, the brackets 50 function to retain the mutually perpendicular relationship of the beam 12 and the two props 20 of each unit 10 while at the same time permitting the beam and props to assume a condition under loading in which they may be pivoted out of such a perpendicular relationship. In particular, the connection of the mount 52 by the pin 46 to the coupling sleeve 34 in combination with the alignment of each prop 20 with each coupling sleeve as a result of the overlapping condition thereof will prevent relative movement between the mount 52 and each prop 20. In mining conditions where the roof R and floor F diverge in relation to each other in a given unit plane P, upward extension of each prop 20 on opposite ends of a beam 12 will result in deflection of the beam from a perpendicular orientation to the props 20. Because the plate 60 abuts the lower web 16 of the beam under the force of the tension spring 62, such deflection of the beam and prop from a perpendicular relationship will result in elongation of the spring and pivotal separation of the plate 60 from the lower web 16 of the beam. When, however, the props 20 are retracted to lower the beam 12 away from the mine roof R, the beam 12 and props 20 will once again assume a truely perpendicular relationship as a result of the tension springs 62 forcing the abutment 60 firmly against the lower web 16 of the beam and the internal surface of the mount 52 against the sleeve 34.
In FIG. 7 of the drawings, an alternative embodiment of the coupling sleeve assembly is shown. In FIG. 7, previously identified and identical parts are identified by the same reference numerals. The only modification in the structure illustrated in FIG. 7 from that shown in FIG. 6 is that the coupling sleeve 34a is elongated to increase the overall height of each prop 20 as may be required for mines of differing roof heights. A filler block 68 is contained within the elongated coupling sleeve 34a so that compressive loading from the bearing block 36 will again be transmitted through the filler block 68 to the upper end of the piston rod 26. The filler block 68 is provided with an oversized transverse bore 70 to accommodate the pin 46 with adequate clearance. An additional pin 72 is provided to couple the lower end of the sleeve 34a to the upper end of the piston rod 26.
With reference again to FIGS. 1 and 2 of the drawings, it will be noted that the successive units 10a-10g are interconnected longitudinally by a pair of struts 74. The struts 74, like the props 20, are in the nature of hydraulic jacks and, as such, include an outer cylinder 76 and a telescopic piston rod 78. The cylinder 76 carries an ear 79 at its base end for securement to a prop 20 through a loose clevis connection 80 having a vertically oriented pin 82. The piston rod 78 is similarly connected through a loose clevis connection 84 to a unit 10. The term "loose clevis connection" is intended to denote a clevis connection which will provide relatively unrestricted pivotal movement about the axis of the pin 82 and, in addition, permit at least limited pivotal movement about an axis transverse to the pin without stressing or otherwise imposing a bending load on the pin 82. The clevis connections 80 and 84 at opposite ends of each strut 74 are so constituted.
To retain the respective props 20 of each unit 10a-10g in a generally perpendicular relationship with the struts 74 in a manner permitting limited canting movement of the props 20 from a truely perpendicular relationship with the struts 74, a prop supporting bracket 86 is connected to each strut and positioned adjacent each prop 20. Specifically, each of the brackets 86 includes upper and lower semicylindrical prop bearing supports 88 and 90 secured by a pair of converging gusset plates 92 and 94 welded or otherwise secured to the end of either the piston rod 78 or the ear 79 at the base end of the cylinder 76 in each strut 74. The prop engaging semicylindrical members 88 and 90 diverge from the axis of the prop 20 as they progress from the strut 74 in a manner such that limited angular movement of the prop relative to the strut will be permitted but only such limited movement. The brackets 88 will function, therefore, to retain the props of each supporting unit 10 in a generally upright or vertical orientation while at the same time permit sufficient limited angular movement between the props and the struts 74 so that the props 20 of any given unit 10a-10g may be elevated with respect to an adjacent unit as may be required as a result of an undulating mine floor F.
Because of the series connection of all support units 10 by the struts 74 and because also of the intradependent connection of all struts 74 and props 20 of the system, only one prop supporting bracket 88 is required for each strut except in one instance. Specifically, the pair of struts 74 connecting the end unit 10g and the props of the unit 10f carry brackets 88 on both ends. By appropriate series relationship, any one set of struts 74 may be so equipped with two brackets 88 in order for the brackets to provide support for all props 20 in the system.
In practice, the system disclosed will be equipped with an appropriate hydraulic actuating system with controls (not shown) by which the respective props 20 as well as the struts 74 may be telescopically extended or retracted under power. In a manner described fully in the prior patents identified above, the system may be advanced under such a controlled hydraulic system by retracting the props of one or more of the units 10a-10g so that the beams 12 thereof are lowered away from the mine roof while the props of at least one or more of the units 10a-10g are extended to force the beam 12 thereof into supporting engagement with the roof R. The retracted units may then be advanced by telescopic extension of the struts 74 using the supporting units for a reaction. Thereafter the previously positioned units will be extended into roof supporting engagement whereas the units previously used for strut reaction will be advanced by telescopic retraction of the appropriate struts 74.
Thus it will be appreciated that as a result of the present invention an improved mine roof supporting system is provided by which the above mentioned objects are fulfilled. Also, it will be apparent to those skilled in the art from the preceding description that modifications and/or changes may be made in the illustrated embodiment without departure from the inventive concept manifested by the disclosed embodiment. Accordingly, it is expressly intended that the foregoing description and accompanying drawings are illustrative of a preferred embodiment only, not limiting, and that the true spirit and scope of the present invention be determined by reference to the appended claims. | A stabilizing arrangement for mine roof support systems of the type in which a series of support units, each including a transverse beam supported at opposite ends by extensible props, are interconnected by extensible struts in a manner to be self-advancing by alternate retraction of support units from a roof supporting condition and extension of the struts to advance such retracted units relative to others of such units which are in an extended roof engaging condition. The connection of each prop to the beam in a given unit is pivotal to allow deflection of the beam and props of a supporting unit from a normal perpendicular relationship under load. The stabilizing means restores the props and beam to a normal perpendicular relationship for advancing movement of each support unit. The supporting units are further stabilized relative to the struts by prop supporting brackets permitting canting movement of the props from a perpendicular relationship with respect to the struts but maintaining the props in a generally upright position for unit advance. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a radio, apparatus used in radio communication systems in which both talking and listening, or transmission and reception, of speech signals are simultaneously performed by using a single frequency.
The definitions of terms used in this specification will be given prior to the description of the invention. A "radio apparatus," as used in this specification, means either an apparatus with an integrated function of both a transmitter and a receiver or an apparatus with a single function of a receiver. A "transceiver" used in this specification means an apparatus with an integrated function of both a transmitter and a receiver, unless it is defined differently in some part of this specification.
Two frequencies for the two directions are generally required for duplex radio communication of transmission and reception. Needless to say, it is preferable that duplex communication is realized by using one frequency for the efficient use of frequency bands
In some fields of applications, the high quality of sounds is not necessarily important. In such cases, the following conventional method has been used for duplex radio communication with a single frequency.
A synchronizing signal generator at an originating call station generates a synchronizing signal for informing another station of switch timing between transmission and reception. A synchronizing signal detector at the incoming call station detects the synchronizing signal contained in a received signal.
The incoming call station has a transmission/reception switching unit for switching between transmission and reception in response to a timing signal generated by the incoming call station itself or the received synchronizing signal, thereby alternately performing synchronous transmission and reception. Specifically, at the originating call station, a voice signal to be transmitted is A/D converted at a predetermined time interval and stored in a memory. The stored data is read at one half the predetermined time interval, D/A converted, and supplied to a modulator during a transmission period to thus transmit the voice signal compressed in one half the actual time period. On the other hand, at the incoming call station, the received voice signal compressed in one half the actual time period is A/D converted at a predetermined time interval and stored in a memory. The stored data is read at twice the predetermined time interval, and D/A converted to obtain a voice signal expanded to the original voice signal. In this way, simultaneous transmission and reception are performed using a single frequency.
When two transceivers are operating in such a simultaneous transmission and reception with a single frequency, a third party station can monitor only voice signals transmitted from only one transceiver which is generating a synchronizing signals in addition to the voice signals, and cannot monitor voice signals transmitted from the other transceiver which operates to receive synchronizing signals. The third party station cannot grasp therefore the full communication between the two transceivers.
One example of the simultaneous transmission and reception communication system is shown in the paper titled "Simultaneous Transmitting and Receiving Method Mobile Radio Using Only One Frequency Channel", Proceedings of the 1992 IEICE (Institute of Electronics, Information & Communication Engineers) Spring Conference, Paper No. B-769, page 3-336, Mar. 15, 1992.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a radio apparatus capable of monitoring the full communication between two transceivers in the simultaneous transmission and reception with a single frequency.
It is a second object of the present invention to provide a radio apparatus capable of switching between the simultaneous transmission and reception communication mode and a monitoring mode.
It is a third object of the present invention to provide a radio apparatus capable of monitoring the contents of communication of either one of two transceivers simultaneous transmission and reception with a single frequency.
According to an embodiment of the present invention, a radio apparatus has a controller which selects either the simultaneous transmission and reception operation or a monitoring operation. In monitoring the contents of communication between the first and second transceivers, the radio apparatus receives voice signals from the first and second transceivers, the first voice signals from the first transceiver are expanded and output from a first D/A converter, and the second voice signals from the second transceiver are expanded and output from a second D/A converter. The two voice signals are added together and reproduced by a loudspeaker of the radio apparatus.
When the controller selects the monitoring operation, this radio apparatus can monitor the voices from both the first and second transceivers operating in simultaneous transmission and reception wherein the originating call transceiver is transmitting synchronizing signals and the incoming call transceiver detecting them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit block diagram of a radio apparatus according to an embodiment of the present invention;
FIG. 2 is a timing chart showing timing of waveforms at various circuit portions, explaining the operation of the radio apparatus of the embodiment;
FIG. 3 is a timing chart showing timing of waveforms at circuit portions, explaining the operation of the radio apparatus of the embodiment;
FIG. 4 is a circuit block diagram of a radio apparatus according to another embodiment of the present invention;
FIG. 5 is a circuit block diagram of a radio apparatus capable of selecting either a simplex voice communication operation or a simultaneous transmission and reception operation with a single frequency;
FIG. 6 is a timing chart showing timings of waveforms at various circuit portions, explaining the operation of the radio apparatus shown in FIG. 5;
FIG. 7 is a schematic diagram showing a communication system which can use the radio apparatus of the present invention; and
FIG. 8 is a circuit block diagram of a radio apparatus according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Prior to the description of the embodiments of the present invention, an example of a radio communication system capable of selecting either a simplex voice communication operation or a simultaneous transmission and reception with a single frequency, will be described with reference to FIGS. 5 and 6. FIG. 5 is a circuit block diagram of a radio apparatus incorporating both a press-to-talk method and a method of the simultaneous transmission and reception with a single frequency. The circuit shown in FIG. 5 is disclosed in the specification of Japanese Patent Application No. 4-269132 (still not laid open) filed on Sept. 14, 1992 and assigned to the same assignee of the present invention.
Referring to FIG. 5, reference numeral 1 represents a voice input unit such as a microphone for inputting voices to be transmitted, reference numeral 2 represents an A/D converter for converting a voice signal to be transmitted into digital data, reference numeral 3 represents a memory for storing digital data, and reference numeral 4 represents a D/A converter for converting digital data read from the memory 3 into analog signals. Reference numeral 7 represents a compression/expansion controller for controlling reading of digital data output from the A/D converter 2 and stored in the memory 3 and to supply the read digital data to the D/A converter 4. For example, the controller 7 controls reading of digital data as data compressed in time by 1/2.
Reference numeral 5 represents an A/D converter for converting a received voice signal into digital data, reference numeral 6 represents a D/A converter for converting digital data read from the memory 3 into analog signals. The compression/expansion controller 7 controls reading of compressed data written in the memory 3 and supplying of the read data to the D/A converter 6 For example, the controller 7 controls reading of digital data as data expanded two-fold, to thereby reproduce original voices.
Reference numeral 8 represents a synchronizing signal detector for detecting a predetermined synchronizing signal contained in a received voice signal, reference numeral 9 represents a transmission/reception switching unit for switching the operation of the radio apparatus to either a transmission mode or a reception mode, reference numeral 10 represents a synchronizing signal generator for generating a synchronizing signal in response to transmission/reception switching and for supplying the synchronizing signal to a modulator 11 which modulates a voice signal to be transmitted, reference numeral 12 represents a demodulator for demodulating a received voice signal, reference numeral 13 represents a transceiver unit, and reference numeral 14 represents a voice output unit such as a loudspeaker from which voices for a received signal are output.
Reference numeral 15 represents a press-to-talk switch used for switching between reception and transmission when the communication apparatus is used as a press-to-talk transceiver. Reference numeral 16 represents a calling switch for starting the simultaneous transmission and reception with a single frequency in synchronism with a synchronizing signal generated by its own radio apparatus. Reference numeral 17 represents a switch for selecting either an ordinary voice signal used for a press-to-talk radio apparatus or a compressed voice signal used for a radio apparatus in the simultaneous transmission and reception with a single frequency. Reference numeral 18 represents a switch for selecting as an input to the loudspeaker 14 either an ordinary voice signal or an expanded voice signal. Reference numeral 19 represents a controller made of a microcomputer and the like. This controller 19 controls the apparatus either as a press-to-talk radio apparatus or a radio apparatus in the simultaneous transmission and reception with a single frequency, depending upon the depression of the switches 15 and 16, and controls the switches 17 and 18, compression/expansion controller 7, transmission/reception unit 9, transceiver unit 13, and other circuits. Reference numeral 29 represents an incoming call switch for starting the simultaneous transmission and reception synchronously with a detected synchronizing signal. If this switch 29 is not being depressed when the synchronizing signal is detected, the radio apparatus continues a reception state. In this case, although the received compressed voice signal is expanded and output, a compressed voice signal is not transmitted. When this switch 29 is depressed, duplex voice communication starts.
The operation of the radio apparatus shown in FIG. 5 will be described. The operation under the conditions wherein no synchronizing signal is being detected and neither the calling switch 16 nor the incoming call switch 29 is depressed, is the same as that of an ordinary simplex radio apparatus, i.e., a press-to-talk transceiver. In this operation, the controller 19 turns the switch 18 to contact a so that an output of the demodulator 12 is directly supplied to the loudspeaker 14. When the contact of the press-to-talk switch 15 is closed, the controller 19 makes the transceiver unit 13 enter a transmission state, and turns the switch 17 to contact a so that voices entered from the microphone 1 are input directly to the modulator 11 and transmitted via the transceiver unit 13.
The timing chart of Fig.6 explains the operation when a synchronizing signal is detected (hereinafter this operation is called an incoming call mode). In FIGS. 5 and 6, reference numeral 23 represents an output from the demodulator 12, reference numeral 24 represents a synchronizing signal detection signal output from the synchronizing signal detector 8, reference numeral 25 represents a transmission/reception switching signal output from the transmission/reception switching unit 9, reference numeral 26 represents an output from the D/A converter 6, reference numeral 27 represents a voice signal output from the microphone 1, and reference numeral 28 represents an output from the D/A converter 4. Reference numeral 30 represents a signal indicating the status of the incoming call switch 29, this signal 30 taking a low (L) level while it is depressed. The controller 19 controls to turn the switch 18 to contact b so that demodulated outputs 23 labeled by A1, A2, and A3 compressed in time by 1/2 and transmitted from the originating call station are passed through a circuitry of A/D converter 5, memory 3, and D/A converter 6 to expand them to original voices under the control of the compression/expansion controller 7, the expanded voices being output from the loudspeaker 14. The level of the transmission/reception switching signal 25 takes the L level until the called switch 29 is depressed, maintaining the transceiver unit 13 in a reception state.
When the incoming call switch 29 is depressed, the controller 19 controls the transmission/reception switching unit 9 to make it deliver the transmission/ reception signal synchronously with the synchronizing signal detection signal. The transmission/reception switching unit 9 makes the transceiver unit 13 alternately switch between the transmission and reception states. The "High" and "Low" level periods of the transmission/reception switching signal 25 indicated at (d) in FIG. 6 correspond to the transmission and reception periods, respectively.
The controller 19 controls to turn the switch 17 to contact b so that a sound signal indicated at (f) in FIG. 6 is passed through a circuitry of the A/D converter 2, memory 3, and D/A converter 4 to compress it by 1/2 under the control of the compression/expansion controller 7, the compressed voice signals labeled by B1 and B2 indicated at (g) in FIG. 6 being supplied to the modulator 11 and transmitted from the transceiver unit 13 during the transmission periods.
The embodiments of the radio apparatus of the present invention will be described with reference to FIG. 1. Prior to giving the description of the radio apparatus shown in FIG. 1, an example of using the radio apparatus shown in FIG. 1 will be explained with reference to FIG. 7. The radio apparatus shown in FIG. 1 corresponds to transceiver C shown in FIG. 7 in which transceiver A as an originating call station and transceiver B as an incoming call station are communicating in the simultaneous transmission and reception with a single frequency. Transceiver C monitors the communication between transceivers A and B. It is obvious that the functions of the transceiver C may be provided to the transceivers A and B.
Referring to FIG. 1, like elements to those explained with FIG. 5 are represented by using identical reference numerals, and the description thereof is omitted. Reference numeral 40 represents a controller for controlling the overall operation of the radio. The controller 40 has a monitoring function specific to the present invention, as well as the functions of the controller 19 shown in FIG. 5, i.e., the function of operating the transceiver either as a press-to-talk simplex voice communication transceiver or as a transceiver of simultaneous transmission and reception. Reference numeral 41 represents a D/A converter which converts digital data from the A/D converter 5 stored in the memory 3 and expanded by the compression/expansion controller 7 into original analog voice signals. Reference numeral 42 represents an adder for adding together a voice signal from the D/A converter 6 and a voice signal from the D/A converter 41.
The operation of monitoring the contents of communication between the transceivers A and B by the radio apparatus of FIG. 1 corresponding to the transceiver C will be described with reference to the timing chart shown in FIG. 2. Consider now the case wherein the switches 15, 16, and 29 are not depressed and the transmission/reception switching signal 25 indicated at (c) in FIG. 2 of the transmission/reception switching unit 9 takes the L level and the transceiver unit 13 is set to a reception mode.
During the simultaneous transmission and reception communication with a single frequency between the transceivers A and B, compressed signals from the transceivers A and B are input via an antenna of the transceiver unit 13 of the transceiver C shown in FIG. 1, and demodulated by the demodulator 12 so as to obtain demodulated signals 23 indicated at (a) in FIG. 2.
A1, A2, . . . , A4 represent compressed signals transmitted from the transceiver A, e.g., signals compressed in time by 1/2, B1, B2, . . . , B4 represent compressed signals transmitted from the transceiver B, e.g., signals compressed in time by 1/2, and S1, S2, . . . , S4 represent synchronizing signals. The synchronizing signal detector 8 receives these compressed signals and generates synchronizing signal detection signals 24 indicated at (b) in FIG. 2 which are then supplied to the controller 40. In order to prevent malfunction of the synchronizing signal detector 8, the controller 40 may be adapted to operate upon reception of, for example, two or more synchronizing signal detection signals 24. When a synchronizing signal detection signal 24 is input to the controller 40, the controller 40 turns the switch 18 to the contact b and controls the compression/expansion controller 7 in the following manner. The controller 40 and compression/expansion controller 7 may be realized by using well known circuit components such as microcomputers.
Under the control by the controller 40, the demodulated signal 23 indicated at (a) in FIG. 2 is stored in the memory 3 via the A/D converter 5 and compression/expansion controller 7. Next, the demodulated signal 23 is read from the memory 3 under the control of the controller 40 while expanding it, for example, substantially doubling the signal. This expanded signal from the transceiver A is supplied to the D/A converter 6 which supplies a signal indicated at (d) in FIG. 2 such as a voice signal (which may be a data signal other than voice signal such as medical data signal from a cardiogram) to the adder 42. On the other hand, the signal from the transceiver B is supplied to the D/A converter 41 which supplies a signal indicated at (e) in FIG. 2 to the adder 42. An output of the adder 42 is supplied to the loudspeaker 14 to reproduce audible sounds such as voices of the signals transmitted from the transceivers A and B.
During the above operation, the transceiver C does not transmit signals and the switch 17 is maintained open.
When the detection of the synchronizing signal detection signal 24 is stopped, the controller 40 turns the switch 18 to the contact a so that an output of the demodulator 12 is directly supplied to the loudspeaker 14. The controller 40 also turns the switch 17 to the contact a to allow a voice signal from the microphone to be directly supplied to the modulator 11. Switching between transmission and reception is effected by the press-to-talk switch 15. In this manner, the operation returns to the simplex communication mode.
The operation in which the switch 29 is depressed while the synchronizing signal 24 is detected, will be described with reference to FIG. 3. This operation is the same as a conventional incoming call mode. Specifically, under the control by the controller 40, the transmission/reception switching unit 9 sends the transmission/reception switching signal 25 indicated at (c) in FIG. 3 to the transceiver unit 13 to control it. The H level corresponds to the transmission period, and the L level corresponds to the reception period. Reference numeral 23 represents an output from the demodulator 12, reference numeral 24 represents the synchronizing signal detection signal, reference numeral 26 represents an output from the D/A converter, reference numeral 27 represents a signal, e.g., a voice signal from the microphone 1, and reference numeral 28 represents an output from the D/A converter 4.
The controller 40 enables the operation of the transmission/reception switching unit 9. This unit 9 then outputs transmission/reception switching signals synchronously with synchronizing signal detection signals, to thereby switch the transceiver unit 13 between transmission and reception.
The compression/expansion controller 7 performs the following operations under the control of the controller 40. In these operations, the transceivers A and C perform the simultaneous transmission and reception using a single frequency.
(1) During the reception period, voice signals 23 labeled by A1, A2, . . . , A in FIG. 3 are input to the A/D converter 5, and their expanded signals 26 shown in FIG. 3 are output from the D/A converter 6. Therefore, signals such as voice signals from the transceiver A are output from the loudspeaker 14 as audible signals.
(2) During the transmission period, signals 27 such as voice signals shown in FIG. 3 input from the microphone 1 to the A/D converter 2 are compressed and output as signals 28 shown in FIG. 3 from the D/A converter 4. The controller 40 turns the switch 17 to the contact b so that the output of the D/A converter 4 is supplied to the modulator 11 and the transceiver unit 13 transmits the compressed signal.
In this manner, the simultaneous transmission and reception with a single frequency is performed synchronously with the synchronizing signal detection signal 24 received from the partner transceiver. When the detection of the synchronizing signal detection signal from the partner receiver is stopped, the controller 40 disables the operation of the transmission/reception switching unit 9. Thereafter, switching between transmission and reception follows the operation of the press-to-talk switch 15. In this case, the controller 40 turns the switch 18 to the contact a so that an output of the demodulator 12 is directly supplied to the loudspeaker 14. The controller 40 turns also the switch 17 to the contact a to allow a signal such as a voice signal from the microphone 1 to be directly supplied to the modulator 11. In this manner, the operation returns to the simplex communication mode.
FIG. 4 shows another embodiment of the present invention. In the embodiment shown in FIG. 1, compressed signals transmitted from the transceivers A and B are stored in the memory. The compressed signals stored in the memory 3 are thereafter read and expanded under the control by the compression/expansion controller 7. The signals from the transceivers A and B are distributed to the D/A converters 6 and 41, respectively, to convert them into analog signals. Therefore, the embodiment shown in FIG. 1 requires expensive two D/A converters and a room for installing them. The embodiment shown in FIG. 4 solves these issues. Specifically, since the D/A converter 4 is not used when the transceiver C monitors the contents of communication between the transceivers A and B, this D/A converter may be used during the monitoring mode in this embodiment. To this end, a switch 44 is provided at the output side of the D/A converter 4. The controller 40 of this embodiment performs the following operations.
Referring to FIG. 4, in the monitoring mode, the switch 44 is turned to contact b. The transmission/reception switching signal 25 from the transmission/reception switching unit 9 takes the "L" level as indicated at (c) in FIG. 2. Signals received by the transceiver unit 13 and output from the A/D converter 5 are signals 23 indicated at (a) in FIG. 2. These signals 23 are stored via the compression/expansion controller 7 into memory 3. The stored signals are read and expanded under the control of the compression/expansion controller 7. In reading and expanding these signals, the controller 40 controls supply of the signals from the transceiver A to the D/A converter 6 which converts the signals into original signals such as voice signals indicated at (d) in FIG. 2. The converted original signals are applied to the adder 42. Signals from the transceiver B are applied to the D/A converter 4 which converts the signals into an original signal such as voice signals like those indicated at (e) in FIG. 2. The converted original signals are applied via the switch 44 to the adder 42. As a result, both signals from the transceivers A and B are supplied from the adder 42 to the loudspeaker 14. In this manner, without using an additional expensive D/A converter, the transceiver having the same functions as the embodiment shown in FIG. 1 can be realized. The other functions not described in this embodiment are similar to the embodiment shown in FIG. 1.
FIG. 8 shows another embodiment of the present invention in which a switch 45 and a switch 44 are provided, the switch 45 being inserted between the switch 40 and the adder 42, and the switch 44 designating whether the switch 45 is to be turned on or off in the monitoring mode.
If the switch 44 is depressed in the monitoring mode, the controller 40 turns on the switch 45. In this case, similar to the embodiment shown in FIG. 4, outputs from the D/A converters 4 and 6 are added by the adder 42 and original signals are reproduced by the loudspeaker 14.
If the switch 44 is not depressed in the monitoring mode, the controller 40 turns off the switch 45 so that an output from the D/A converter 4 is not supplied to the adder 42. In this case, only an output from the D/A converter 6 is reproduced by the loudspeaker 14.
With this embodiment, the transceiver C can receive both voices from the transceiver A which generates synchronizing signals and from the transceiver B which performs the simultaneous transmission and reception communication synchronously with received synchronizing signals, or only the voice from the transceiver A.
The radio apparatus of the embodiments has both the transmission and reception functions. If only the monitoring function is required, the radio apparatus may have only the reception function.
According to the present invention, in the communication area where two transceivers operate, the radio apparatus of the invention can receive both voices from one transceiver (originating call station) which generates synchronizing signals and from another transceiver (incoming call station) which performs the simultaneous transmission and reception communication synchronously with received synchronizing signals, or only the voice from the transceiver (originating call station). It is therefore possible to provide the simultaneous transmission and reception with a single frequency communication apparatus which is excellent in practical use.
Many different embodiments of the present invention may be constructed without departing from the spirit and scope of the invention. It should be understood that the present invention is not limited to the specific embodiments described in this specification. To the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims. | A radio apparatus having a unit for receiving a first signal from a first transceiver compressed in time by a predetermined rate, a unit for reproducing a first original signal from the first signal, a unit for receiving a second signal from a second transceiver compressed by the predetermined rate during the reception period of the first transceiver, a unit for reproducing a second original signal from the second signal, and a unit for adding the first and second original signals and outputting the added signal. | 7 |
This application is a division of application Ser. No. 325,059, filed Nov. 25, 1981, U.S. Pat. No. 4,440,808.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for uniformly applying liquid treating media to workpiece webs. The liquid treating media are to be foamed and applied to the workpiece in foamed condition.
A basic apparatus and method for this purpose have been disclosed in German Published Application DE-OS 2,523,062 which makes the advantages of applying the treating media in foamed state very clear. The known apparatus has a container above the workpiece, and the foam is deposited within this container, and is then squeezed through a wall of the container into the workpiece.
A problem with this approach is that the direct application of the foamed medium to the workpiece does not necessarily result in proper entry of the medium into the workpiece surface; depending upon the physical surface characteristics of the workpiece, surface differences from location to location, the chemical condition of the workpiece surface and the uniformity of any chemical application (or even the condition within the confines of the workpiece), the foam bubbles will burst at different rates of speed so that different quantities of released treating liquid are available for different surface areas. In other words: application of the foam to the workpiece and squeezing of the foam into the workpiece through a side edge of the application chamber does not assure uniform entry of the foam into the workpiece.
On the other hand, it is desired that foam carrying e.g. liquid ink particles or other substances transport liquid only in minimum quantities and that this liquid be completely yielded up to (absorbed by) the workpiece.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the invention is to provide an improved apparatus for treating a workpiece web with foamed treating medium.
Another object of the invention is to ensure that the foam is deeply transported into the structure of the workpiece and that the surface of the workpiece is also provided with released (by the foam) liquid treating medium.
A concomitant object of the invention is to deposit the foam over a very small surface area of the workpiece at any one time.
In the apparatus according to the invention, the foamed treating medium is applied to the workpiece within a four-sidedly delimited area, whereupon it is first drawn into the workpiece by suction and subsequently pressed in by squeezing. An advantage of this procedure is that the liquid carried by the sucked-in foam reaches deep into the workpiece (possibly as deep as the substrate) whereas the surface of the workpiece receives liquid foam bubbles which burst when squeezed into the surface. This eliminates the soaked "grey-veil" effect, which is especially important in the case of napped fabrics, for example carpeting or the like.
It is well known that napped textiles come in various degrees of hardness. According to the invention it has now been found that especially in the harder qualities of such textiles the surface structure of the workpiece acts in effect as a sieve or screen. This means that the workpiece surface structure destroys the foam bubbles, causing them to release their contained liquid; the application of this liquid is completely uniform over the entire area of application. The quantity of foam supplied per unit time is adjustable, and the vacuum used to draw it into the workpiece is also variable. This means that the quantity of liquid entering the workpiece per unit time can be maintained within a desired tolerance range of 1 to 5% in relationship to the liquid which it is desired to apply per surface area. This very exact result cannot be achieved with the prior art, since the angle of the side edge of the prior-art box is not variable; even if a doctor blade were used at this point, this could not change the quantity of liquid entering the workpiece.
The apparatus for carrying out the invention comprises a container defining above the workpiece a space which is closed at four sides, at one side by an applicator device such as a squeegee. Below the plane of passage of the workpiece, there is arranged a suction generating device; as considered in the direction of workpiece movement, the application device is arranged downstream of the suction generating device.
A supply device may be provided which feeds the foamed treating medium into the container, one wall of which is wholly or in part constituted by the applicator device. The suction generating device may be a suction box with a suction slot. The applicator device downstream of the suction generating device may be a roller squeegee which may or may not be separately driven. The suction of the suction generating device is variable and the suction generating device may be located immediately upstream of the roller squeegee. Both the applicator device and the suction generating device preferably extend all the way across the working width of the apparatus.
When the foam is applied to the workpiece, it is destroyed (the bubbles burst) and a minimum but adequate amount of released treating liquid is then available uniformly over the entire surface area of the workpiece, since such uniformity is ensured by the applied suction which also determines the amount of liquid that is allowed to remain at the surface of the workpiece (instead of being drawn in).
A further advantage of using relatively low-grade adjustable suction resides in the fact that air is withdrawn from the interstices of the workpiece, thus allowing the liquid released by bursting of the foam bubbles to enter the workpiece much more easily. Also, mechanical resistance at the workpiece surface is thereby eliminated.
On the other hand, the additional mechanical squeegeeing of the foam, preferably but not necessarily by a roller squeegee, at a location downstream of the suction application, has the advantage that any not already burst bubbles are now definitely burst and made to release their liquid; further, it removes residual foam and liquid from the workpiece surface.
The invention is particularly suited for continuous operation. However, discontinuous operation is certainly possible. It would then only be necessary to make the suction device (and preferably the squeegee) movable backwards and forwards in direction of workpiece movement.
The invention will hereafter be described with reference to examplary embodiments. These, however, are merely for the purpose of explanation.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic side elevational view of one embodiment of an apparatus according to the invention;
FIG. 2 is a similar view, but of a different apparatus for discontinuous operation;
FIG. 3 is a view analogous to that of FIG. 1, but illustrating a further apparatus; and
FIG. 4 is a diagrammatic side elevational view, illustrating an apparatus according to the invention and a foam generator therefor.
DESCRIPTION OF PREFERRED EMBODIMENTS
Common to the apparatus of all embodiments is that they serve for the uniform application of liquid but foamed treating media to any kind of textile workpieces, especially workpiece webs. The invention is especially useful in napped workpieces, such as carpeting or the like, but is not limited thereto. The method will be explained in conjunction with the operation of the apparatus.
In FIG. 1, reference numeral 2 identifies the foam supply device which may be a hose, pipe or duct provided with outlets 20 which are uniformly spaced over the width of the workpiece. The foam generator will be described with reference to FIG. 4.
The workpiece 1 can--and, in view of the application of suction, as a rule will--rest on an air-permeable printing blanket 3. This may be endless, as shown in FIG. 2. However, instead of a printing blanket the workpiece may pass over a known-per-se screen drum in which the suction device 4 is then arranged. In the embodiments of FIGS. 1, 2 and 3 (in all embodiments like reference numerals identify like elements) the suction device is a suction box which extends over the entire working width of the apparatus and is provided with a suction slot 40. If a screen drum is used (not shown) the suction device will be of segmental shape.
FIG. 1 shows that atop the textile workpiece 1 there is arranged a space--e.g. the interior of a container 5--bounded on four sides but open to the workpiece. The foamed medium is deposited in this space by the device 2. In place of a container 5, sidewalls 50 could be used which could be adjustable relative to one another, and a front wall 55 be provided at the side at which the workpiece is incoming (as considered in the direction of workpiece movement).
Arranged below the container 5 or its substitute is the suction device 4 with its suction slot 40. Device 4 is connected with vacuum pump 41. The suction regulation is effected via a valve 141 or the like. Pump 41 can be connected with the suction device 4 via a hose (FIG. 4) or a stationary pipe 42'. What type of known-per-se vacuum pump or producer is used, is immaterial. Suction device 4 should be adjustable in its position (in the movement direction of the workpiece), but should preferably be fixed once it is set to a selected spot.
The rear wall 52 (as considered in the direction of workpiece movement) is partly formed by the applicator device 6. In FIG. 1 this is a doctor blade whose angle in relation to the movement of the workpiece is adjustable. The workpiece 1 on the printing blanket thus passes under the container 5 and over the suction device 4, whereupon it travels under the mechanical doctor blade so that the foam, after being sucked into the workpiece, is also pressed into the surface layer of the same. The wall 52 above device 6 prevents overflowing of the foam.
FIG. 2 shows a somewhat similar apparatus with an applicator device 6 which this time is constructed as a roller squeegee. The front wall 55 is supported on a traverse member 51 which can be secured in the machine frame at opposite sides of the apparatus; it is adjustable in the indicated arrow directions and can be arrested at any desired distance from the applicator device 6. Wall 55 may be specially profiled to form a channel 53 through which the foam can most expeditiously flow downwards.
Rear wall 52 is supported via a sealing strip 152 on the surface of the roller squeegee 6; the seal is adjustable to keep it tight. This wall, also, is supported on a traverse member which can be secured to the left and right of the workpiece in the machine frame. Suction device 4 is similar to the one in FIG. 1.
The embodiment of FIG. 3 has another roller squeegee as the applicator device 6; but it has a stationary container 5 and therebelow a suction device 4.
The Figures all show that the printing blanket 3 can be guided over rollers 30, 31. Evidently, it is both air and liquid-permeable. The rollers for it can be driven continuously or discontinuously; the former is generally preferred.
The low-grade vacuum, whose strength can be controlled, removes air from the workpiece so that a uniform, resistance-free entry of the liquid into the workpiece is obtained.
All embodiments show a napped workpiece, because the invention is particularly advantageous for such material. The suction generating device may also be an area-spanning box.
Due to the adjustability of the portion of the suction device 4 relative to applicator device 6 (e.g. roller squeegee) the effect of the suction device can be further selected. If it is desired to first remove air from the workpiece, the suction slot is located further away from device 6. If an effect is to be obtained on the already mechanically pressurized foam, the suction slot 40 is located close to the applicator device 6 (e.g. roller squeegee) under the wedge 60 located ahead of the applicator device 6.
FIG. 4, finally, shows one embodiment of a foam generator for the apparatus in FIGS. 1-4. the liquid treating agent (of any kind that can be foamed) is contained in a reservoir 90. Compressed air is supplied from a compressor 91 or analogous device. The two are connected with a mixing head 94 via conduits 190, 191 in which quantity-measuring devices (known-per-se) 290 and 291 are installed. Control valves are also provided; only the valve 92 for conduit 191 is shown.
Liquid is pumped from reservoir 90 via a pump 93 which is driven by a motor 193 via a transmission 293. Thus, both liquid and compressed air enter the mixing head 94 which has a mixing chamber 194 containing glass beads, granulate or the like to aid in the foam formation. The compressed air is admitted into an annular space 294 surrounding chamber 194 and enters the same from below via appropriate openings. The thus created foam is then passed via a conduit, pipe, hose or the like 95 in a precisely set mixing ratio to the device 2, and from there onto the workpiece. A main shut-off valve 96 is interposed in air line 191.
The stream of foam flowing towards the point of application should be continuous and the rate of feeding the foam should match the consumption.
The squeegee device and the suction generating device can be built as a compact unit. The device 4 can be built so that the suction generating device and squeegee device work upon the opposite sides of the same portion of the substrate.
While the invention has been described with reference to exemplary embodiments, these are not intended to be limiting. Rather, the concept of the invention is expressed exclusively in the appended claims. | Apparatus is used to uniformly apply liquid treating medium to a textile workpiece by foaming it, depositing the foam in a confined space atop the workpiece, applying suction to the workpiece from below and then, at a location downstream of the suction, squeegeeing additional foam into the surface layer of the workpiece. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 11/479,847 filed on Jun. 30, 2006, which claims priority to European Patent Application No. 050105995.4, filed Jan. 7, 2005, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method, a system, and a computer program product for managing virtual instances of a physical port attached to a network.
2. Background Art
More specifically, the invention relates to a network, in which each connected computer or device has a unique identifier. As an example, a network with Fibre Channel connections is described.
Functionally, the Fibre Channel (FC) is a bi-directional, full-duplex, point-to-point, serial data channel structured for high performance data communication. The FC provides a generalized transport mechanism that has no protocol of its own or a native input/output command set, but can transport any existing Upper Level Protocols (ULPs) such as FCP, the “Fibre Channel Protocol for SCSI (Small Computer System Interface)”, and IP, the Internet Protocol.
The smallest, indivisible unit of information transfer used by FC is called a frame. Frames are used for transferring data. The frame size depends on the hardware implementation and is independent of the ULP or the application software. These frames are aggregated to form messages called sequences. The frames of a sequence can be received out of order. One or more sequences form an exchange, which is a basic transaction. The frames are divided in two categories: link control frames without data payloads, which are used for the flow control, and data frames with data payloads such as encapsulated ULP data.
Various FC standards exist, for example the following references:
1. Information Technology—Fibre Channel Protocol for SCSI, 2 nd Version (FCP-2), ANSI/INCITS 350 2. Information Technology—Fibre Channel Framing and Signalling Interface (FC-FS), ANSI/INCITS 373.
Further details about FC can be found for example in Robert W. Kembel, “The Fibre Channel Consultant—A Comprehensive Introduction”, 1998.
Connecting a computer or other device to a FC requires specific hardware. FC hardware is usually provided in the form of FC adapter cards which are plugged in existing input/output (I/O) hardware such as PCI/PCI-X/PCI-Express slots of a computer system. Every FC adapter contains at least one N_Port, a FC hardware entity which performs the actual data communication over the FC link.
An N_Port is identifiable by a unique Worldwide Port Name (WWPN) implemented as a 64-bit value. This WWPN is normally assigned at manufacturing time of the FC hardware, but may also be assigned by other means, provided that the port name can be guaranteed to be unique worldwide. An N_Port can act as an originator or a responder.
FC connections may be implemented as a point-to-point link, or an arbitrated loop or a switching network, called a fabric.
A FC fabric is an interconnection network that allows multiple N_Ports to intercommunicate. The entry/exit ports on a fabric are called F_Ports, and each N_Port has to connect to one F_Port. The fabric allows each connected N_Port to communicate with any other N_Port that is attached to the fabric.
The FC fabric assigns to each attached N_Port an identifier, which is an address by which an N_Port is uniquely known for the fabric. Since the N_Port identifier is a 24-bit value, a FC fabric can support up to 16.7 million N_Ports. The N_Port identifier consists of a Domain (most significant byte), an Area, and a Port, each 1 byte long. The N_Port identifier is used in the Source Identifier (S_ID) and Destination Identifier (D_ID) fields of the header of a FC frame.
Initiating communications in a fabric requires a multistage login process in which communications are first established between an N-port and an F-port in the fabric and then with the destination N-port. In the first step, the fabric login of the N_Port establishes the classes of service to be used within the fabric and other communications parameters including flow control information. After the fabric login of the N_Port completes, the initiating and recipient N-ports in the network establish communications with each other through a second login process called node logic Several communication parameters are exchanged and the transmission starts. As FC can be used to connect systems with multiple types of internal resources and processes within, an additional login called a process login is used. For example, the process login is used to select parameters related to an ULP supported by processes within two communicating N_Ports.
The vast majority of today's FC adapters provide one N_Port only. In a computer executing multiple operating system (OS) instances, the problem occurs how to share such an N_Port among these instances. Such sharing would be advantageous to minimize the number of FC adapters, to reduce cost and to maximize adapter utilization, especially for large scale virtualisation environments. The problem exists even when using FC adapters providing multiple N_Ports since the number of processes needing to be supported often exceeds the number of N_Ports provided by the FC adapters.
The capability to execute multiple OS instances is usually provided by a software layer called (execution) hypervisor that encapsulates the underlying hardware and provides virtual hardware interfaces either for the underlying hardware or for different hardware architectures. For example, a hypervisor can be part of the firmware of a computer system, it can be part of an operating system, or it can be a regular program running as a process within an OS instance. The work of the hypervisor is often supported by additional hardware features, for example special processor instructions or firmware layers.
Some hypervisors can effectively create multiple virtual images of a computer system, giving an OS instance executing in such a virtual computer system almost the illusion as if it was running exclusively on the real server. These OS instances access real I/O entities (like adapters) via I/O ports, which can be defined and assigned to a virtual computer system in a configuration step. An OS instance may only perform I/O operations using I/O ports assigned to the particular virtual server on which it is running.
The U.S. patent applications No. 2003/0200247A1 and No. 2004/0025166A1 describe a method for the concurrent sharing of a FC adapter among multiple OS instances in a computer system. However, this sharing capability has various deficiencies caused by the fact that the same N_Port identifier is used for all FC frames sent from or destined to a particular FC adapter. Consequently, this N_Port identifier cannot be used to distinguish multiple OS instances: All of the frames seem to come from the same initiator, and responses are accordingly sent back to the same address. The solution proposed in the above patent applications is to intercept, analyse, and modify the FC frame traffic between the multiple OS instances and the physical N_Port.
A major disadvantage is that this solution is host-based, which means that the approach needs to be performed on a host computer system that is attached to a FC fabric. Since FC is a technology used mainly for Storage Area Networks (SAN), and the usual method for access control in the SAN and its attached storage devices is managed by the SAN itself (using databases stored in the fabric), this adds additional complexity to the SAN management and administration.
Another disadvantage is that it is not possible to initiate a FC transaction to a particular OS instance from outside of the computer system executing the multiple OS instances. This limitation is caused by the need for the unequivocal response identifier that gets added to the frame header when it gets intercepted. There is only one response identifier to be used for frames that will be sent to a particular OS instance. Without being able to identify the specific OS instance, any incoming frame has to be forwarded to every OS instance. An OS instance needs to decide then if it will accept and process the frame.
Other deficiencies that exist in such a shared adapter environment are related to ULPs such as FCP; for example, SCSI reservations do not work properly, correct SCSI status and sense data handling cannot be guaranteed, SCSI task management functions do not work properly, and vendor-unique SCSI commands might not work at all.
SAN access control for the connected storage controllers of a fabric is typically implemented by methods like zoning and SCSI Logical Unit (LUN) masking. Zoning and LUN masking rely on WWPNs to identify users of controlled assets. Using a LUN and FCP as the ULP, a FC host can address multiple peripheral devices that may share a common controller. Zoning allows partitioning the N_Ports of a fabric into N_Port groups, called zones. The N_Port within a zone can only communicate with other N_Ports in the same zone.
One way to solve the FC adapter sharing problem was disclosed in the U.S. patent application No. 2003/0103504A1 and later on incorporated in the INCITS/ANSI FC Framing and Signalling (FC-FS) standard 1.6, which describes how a fabric needs to handle N_Port identifier virtualisation. The application describes a method to obtain multiple N_Port identifiers (N_Port IDs) for a single physical N_Port.
In order to obtain an N_Port identifier, the N_Port first logs in with the fabric by sending a “Fabric Login” (FLOGI) extended link service (ELS) command (a special link control frame) to the attached F_Port. In this step additional service parameters will be transferred, and the first N_Port identifier is assigned. After FLOGI is complete, the fabric prepares itself to assign additional N_Port identifiers. In order to obtain another N_Port identifier, the N_Port sends a “Fabric Discover” (FDISC) ELS command using an S_ID of zero. The FDISC ELS is used instead of additional FLOGI commands to avoid disruption of the operating environment. When the N_Port sends the FDISC ELS to the fabric, it provides the following functions:
1. It provides the means for the physical N_Port to transfer a WWPN to the fabric. 2. It provides a signal to the fabric to validate and assign an additional N_Port identifier for the physical N_Port, and allows both the fabric and the physical N_Port to begin normal frame reception and transmission using the new N_Port identifier. 3. It provides a signal which causes the fabric to update databases maintained within the fabric.
When the new N_Port ID has been assigned, the physical N_Port can associate the new N_Port ID with a virtual adapter, which is an entity behind the physical N_Port that generates and receives frames using the new N_Port ID on behalf of an OS instance. Therefore, multiple virtual adapters can be associated with a physical adapter and its N_Port, where each virtual adapter uses a unique N_Port ID.
The assignment of new N_Port IDs requires the availability of unique WWPNs and means for the automatic and persistent assignment of these WWPNs to virtual adapters, where persistent can mean surviving e.g. a reboot of an OS instance, a power-off/power-on cycle of the computer system, or a reboot of a FC adapter. In large scale computer centres with complex SAN installations it can become therefore a very complex task to ensure that every WWPN in use is really unique.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention, to provide a method for managing virtual instances of a physical port attached to a network that is improved over the prior art and a corresponding computer system and a computer program product.
This object is achieved by the invention as defined in the accompanying claims 1 , 9 , 10 and 12 .
The present invention proposes a FC adapter virtualisation entity that can be used to provide multiple virtual FC adapters for a single physical FC adapter as a way to share this FC adapter among multiple OS instances. Each virtual adapter has a single N_Port ID. If the physical FC adapter has multiple physical N_Ports, then independent sets of virtual adapters can be associated with each of the N_Ports of that physical adapter.
The FC adapter virtualisation entity obtains a WWPN for each I/O port that is defined in a hypervisor system configuration from a FC virtual adapter name controller entity. This entity may create a WWPN using a scheme or just take it from a pool of WWPNs. It is possible that the WWPN of a physical N_Port of the physical FC adapter is used for a virtual FC adapter. The FC virtual adapter name controller ensures the worldwide uniqueness for a WWPN that it provides.
A virtual FC adapter may be created when an OS instance activates an I/O port, or it maybe created in advance in order to save the time for its initialisation, and be associated to the I/O port when that I/O port is activated. In any case, when the virtual adapter is associated to an I/O port, it uses the WWPN of that I/O port in order to perform a fabric login using the FDISC ELS command and to acquire a corresponding FC N_Port ID. The WWPN remains associated with the virtual adapter as long as the virtual adapter is tied to that particular I/O port.
The association of an I/O port and its WWPN can be made persistent by storing related tables on a storage device coupled to the computer system. This way a power-off/power-on cycle of the computer system or a restart of the hypervisor has no influence to the mapping of a WWPN to an I/O port. The WWPN, through the issuance of FDISC and the assignment of an N_Port ID for the WWPN, ensures that only properly authorized virtual servers and operating system instances can reach their assigned resources.
The present invention allows sharing a single physical FC adapter among multiple OS instances transparently. The adapter is shared automatically without any special commands required by the OS instances.
A further important aspect of the invention is that it supports the regular SAN management and administration models such as zoning and LUN masking transparently. This avoids host-based SAN management and administration steps and the attendant problems previously described. This also reduces the SAN management and administration complexity significantly. This eliminates restrictions for ULPs such as FCP.
Another aspect of the invention is that a FC transaction using a virtual adapter can get initiated from outside of the computer system and directed to a particular OS instance.
The invention allows defining virtual adapter characteristics, for example performance characteristics such as adapter bandwidth. This allows balancing between the virtual adapters that share the same physical N_Port based on the performance needs of each virtual adapter.
BRIEF DESCRIPTION OF THE DRAWINGS
For the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.
FIG. 1 : Is a block diagram of a computer system into which the invention can be implemented;
FIG. 2 : Is a block diagram of the encapsulation of a FC adapter by a hypervisor that controls multiple OS instances;
FIG. 3 : Is a block diagram of a hypervisor embodiment in accordance with the invention;
FIG. 4 : Is an illustrative flow chart of an embodiment of a method in accordance with the invention;
FIG. 5 : Is an illustrative flow chart of an embodiment of a method in accordance with the invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a computer system 10 in which the present invention can be used. A shared memory 11 is coupled to one or more Central Processing Units (CPUs) 12 . These CPUs 12 are also coupled to an I/O subsystem 13 . A separate storage device 14 can also be accessed by the CPUs 12 . The content of the storage device 14 is persistent: It survives a power off/power-on cycle. A FC adapter 15 is accessible for the CPUs 12 via the I/O subsystem 13 , and this FC adapter 15 is connected to a FC fabric 16 . The FC adapter 15 has a physical N_Port 17 that is connected to an F_Port 18 of the fabric 16 .
As shown in FIG. 2 , the computer system is running a hypervisor 20 on the CPUs 12 , which controls multiple OS instances 21 that are executed concurrently. The hypervisor 20 emulates the FC adapter 15 ; the OS instances 21 perceive the normal FC adapter interface, but in fact have I/O requests processed through the hypervisor 20 in order to access the FC adapter 15 . The component of the hypervisor that is responsible for the interface to the OS instances 21 is called the virtual machine interface (VMI) 22 . The VMI 22 can be any kind of computer interface usable by software. In the preferred embodiment of the invention the storage device 14 is used to store internal data of the hypervisor 20 and not directly accessible by the OS instances 21 .
A FC Adapter Virtualisation Entity (AVE) 30 is now implemented as a component of the hypervisor 20 shown in FIG. 3 . Its purpose is to intercept I/O requests from the OS instances 21 accessing the FC adapter 15 . Typically, an OS instance 21 a makes I/O requests in a communication unit 31 . Such a communication unit 31 can be implemented as a device driver for example.
The communication unit 31 uses an I/O port 32 to communicate with a FC adapter 15 . For the purposes of the present invention it is sufficient that the I/O port 32 comprises a request queue and a response queue. These queues will be used by the AVE 30 and the communication unit 31 . The communication unit places requests for the FC adapter 15 in the request queue. A request contains addresses of the memory 11 that allow the AVE 30 to access data stored in the memory 11 that can be associated with such a request. This data comprises FC frames that will be forwarded by the AVE 30 to the FC adapter 15 . The hypervisor 20 places responses from the FC adapter 15 in the response queue. A response contains addresses of the memory 11 that allow the communication unit to access data stored in the memory 11 by the hypervisor 20 . The data in the memory 11 also comprises FC frames that have been received by the FC adapter 15 .
In order to use an I/O port 32 it needs to be activated by a communication unit 31 as it would without the present invention. For every activated I/O port 32 , the AVE 30 creates special data structures in the memory 11 . These data structures are called a virtual FC adapter. Among associated interfaces of the hypervisor 20 are interfaces that allow an OS instance 21 a to send and receive FC frames. The special data structures are used for the implementation of these interfaces.
During the I/O port activation, the AVE 30 obtains a new N_Port identifier from the fabric 16 (as described earlier) that is associated with the I/O port 32 and stored in the corresponding virtual adapter. For each frame that is sent from a communication unit 31 using this I/O port 32 the AVE 30 puts the N_Port ID associated with this I/O port 32 in the S_ID field of the FC frame header. Accordingly, all FC frames received by the AVE 30 from the fabric 16 that carry this N_Port ID in the D_ID field of the frame header are forwarded via this I/O port 32 to the corresponding OS instance 21 a.
An I/O port 32 is generated by the hypervisor 20 in a special system configuration step. In this step, the AVE 30 uses a Virtual Adapter Name Controller (VA-NC) 33 entity to assign a WWPN to the I/O port 32 . The VA-NC 33 maintains a pool 34 of WWPNs, from which it takes one WWPN that is assigned to the I/O port 32 and removed from the pool 34 . WWPNs that have been assigned to an I/O port 32 are maintained by the VA-NC 33 in a table 35 called the Virtual Adapter Name Assignment Table (VA-NAT), which is stored on the persistent storage device 14 . In the system configuration step the association of an I/O port 32 to an OS instance 21 a is also defined. There is no restriction that a communication unit 31 can use one I/O port only.
The steps for the I/O port 32 activation are shown in FIG. 4 . The communication unit 31 triggers the activation of the I/O port 32 (step 40 ). If (step 41 ) the I/O port 32 is already activated, then (step 42 ) the AVE 30 presents an error to the communication unit 31 . Otherwise the WWPN of the I/O port 32 will be used to log in the fabric 16 using the FDISC ELS command (step 43 ). If (step 44 ) the login is not successful, then (step 45 ) the AVE 30 presents an error to the communication unit. Otherwise the AVE 30 marks the I/O port 32 as activated, stores the N_Port ID provided by the fabric 16 in the virtual adapter (step 46 ), and returns to the communication unit 31 (step 47 ).
FIG. 5 shows the steps for the I/O port 32 deactivation. The communication unit 31 triggers the deactivation of an I/O port 32 (step 50 ). If (step 51 ) the I/O port 32 is not activated, the AVE presents an error to the communication unit 31 (step 52 ). Otherwise the N_Port ID associated to the I/O port 32 will be logged out of the fabric 16 (step 53 ) using well-known methods described in reference 2 . If (step 54 ) the logout is not successful, then the AVE 30 presents an error to the communication unit 31 (step 55 ). Otherwise (step 56 ) the I/O port 32 will be marked as deactivated, and the associated N_Port ID entry for the WWPN will be deleted in the virtual adapter. Afterwards the AVE 30 finishes the deactivation successfully (step 57 ).
I/O ports that have been generated in a configuration step of the hypervisor 20 can be removed from the system configuration. If an I/O port is removed from the system configuration, the corresponding WWPN is added to the pool of WWPNs 34 again and marked as “locked”. The VA-NC 33 will not use a WWPN that is marked “locked” for the assignment to a newly created I/O port 32 , i.e. I/O ports that are subsequently added to the system configuration.
The locking of a WWPN when its associated I/O port 32 has been removed from the system configuration of the hypervisor 20 has to be done in order to avoid that this WWPN could be assigned again to another I/O port 32 that gets added to the system configuration of the hypervisor 20 . This would be the case if access rules are still established in the SAN for this WWPN, for example a LUN mask setting granting this WWPN access to certain devices (LUNs). But often such a re-use of a WWPN with a new I/O port is not intended, as only certain OS instances are meant to use certain resources in the SAN.
Therefore, to recover these locked WWPNs, and to prevent the situations where no WWPN can be assigned to an I/O port because all available WWPNs are either locked or in use, the VA-NC 33 adds an interface to the hypervisor 20 that allows unlocking a WWPN. So for example a system administrator can unlock a WWPN for which it was verified that no unintended access rights are in place, and therefore it is safe to reassign this WWPN to an I/O port 32 that can be assigned to any operating system instance 21 a.
In an embodiment of the invention, WWPNs that were associated to I/O ports that have been removed from the system configuration of the hypervisor 20 are added to a least-recently-used list 36 stored in the memory 11 (or on the persistent storage device 14 ).
This least-recently-used list 36 is implemented as a first-in first-out list. An entry of this list 36 contains a WWPN together with an identifier for the I/O port 32 to which the WWPN was assigned. Should the same I/O port 32 (as indicated by the identifier) be redefined again while the corresponding WWPN is still in the least-recently-used list 36 , then the same WWPN will be assigned to that I/O port 32 again. This way there is no need to reconfigure the SAN as would be the case when an I/O port 32 is temporarily removed from the system configuration of the hypervisor 20 , and another WWPN would be assigned to the I/O port 32 when the I/O port 32 gets added to the system configuration of the hypervisor 20 again.
The length of the least-recently-used list 36 may be limited such that not all possible WWPNs that fall out of the AV-NAT 35 can be kept in this table. If a WWPN falls out of the least-recently-used list, it will be added to the pool of WWPNs 34 again and still remain marked as “locked”. Instead of maintaining the least-recently-used list 36 as a first-in first-out list, various other strategies are possible for the decision to remove an entry from the list 36 .
The use of the least-recently-used list 36 may save a considerable amount of the memory 11 for large and dynamically changing system configurations of the hypervisor 20 as all the memory allocated for the special data structures of the virtual adapters associated with the locked WWPNs can be released. Otherwise it would be required to keep the I/O ports and their associated virtual adapters in order to avoid the SAN reconfiguration.
The WWPNs stored in the pool 34 are assigned to the computer system 10 and the pool 34 is stored on the persistent storage device 14 . If the WWPNs do not need to be worldwide unique because they will be used in a configuration that is completely isolated from all other SANs, the VA-NC 33 can also use a scheme to generate a WWPN for a new I/O port definition instead of taking it out of the pool 34 of WWPNs. A possible scheme is to use a common prefix that will be combined with an identifier for the I/O port 32 .
A scheme can also be used to generate WWPNs that are really unique worldwide. For this scheme a worldwide unique prefix would be assigned to the computer system 10 , and this prefix would be combined with the identifier for the I/O port 32 for example. In yet another embodiment, the physical N_Port and its associated WWPN is used in shared mode as described in the U.S. patent application No. 2003/0200247A1, using the access control mechanism as described in the U.S. patent application No. 2004/0025166A1. This can be exploited if the number of OS instances 21 that need to concurrently share a physical N_Port is larger than the number of virtual adapters that can be supported on the physical N_Port. In another embodiment, also one or more virtual adapters with their associated configured WWPNs can be used as shared virtual adapters in the same way.
In one embodiment of the present invention the VA-NC 32 adds an interface to the hypervisor 20 that allows querying for the WWPN and the N_Port ID currently assigned to an I/O port. This can be used by an OS instance 21 a for SAN management and administration purposes.
The first login from a physical N_Port 17 to the fabric 16 must always be done using the FLOGI ELS command. In one embodiment, the WWPN assigned to the physical N_Port 17 is used for this FLOGI-type login. Although the FC-FS standard (see reference 1 ) would allow the logout of the N_Port 17 , which did the FLOGI login from the fabric 16 while other fabric 16 logins from virtual adapters associated with the N_Port 17 are still active, it may cause problems when the N_Port 17 is logged in the fabric 16 again. The reason is that the WWPN specified with the FLOGI is used as a permanent port name for the physical N_Port, and remains associated with this N_Port and maintained by the fabric 16 as long as any login for this physical N_Port is still active. Specifically, if the FLOGI login is revoked by a corresponding logout while an FDISC login is still active, and now the WWPN used previously for the FLOGI login is used for another login into the fabric 16 , the fabric 16 may see the same WWPN twice, which may cause disturbances to SAN management applications.
Therefore, in an embodiment of the invention the N_Port ID assigned by the fabric 16 for the WWPN of the N_Port 17 used for the FLOGI-type login is not logged out (see step 54 ) during the deactivation of an I/O port 32 associated to this N_Port ID when additional N_Port IDs for this physical N_Port are still logged in the fabric 16 , which means that I/O ports 32 associated to these N_Port IDs are still active.
It is possible that an N_Port can become disconnected from the fabric 16 . If this occurs all the FC frames for incomplete exchanges using the N_Port are invalidated and all the N_Port IDs are automatically logged out of the fabric 16 . Depending on its type, a disconnection is indicated by the FC adapter 15 by either sending a FC frame indicating unsolicited status to the AVE 30 or by storing a special value in a register of the FC adapter 15 that is accessible for the AVE 30 . The AVE 30 informs an affected OS instance 21 b that its virtual adapters have been logged out. For each N_Port ID that was logged out as a result of the disconnection, the affected communication units 31 need to deactivate their affected I/O ports 32 and activate them again.
In order to minimize the impact of an N_Port disconnection to application programs in an OS instance 21 b affected by that disconnection, I/O ports 32 can be prioritized for re-activation. A simple prioritisation solution is that the AVE 30 uses a priority list of I/O ports in the memory 11 that were active before. For every I/O port 32 activation, the AVE 30 searches this priority list and if it finds the I/O port in the priority list (that is, the activation is a re-activation of a disconnected I/O port), the activation continues immediately. Otherwise the AVE 30 waits a certain amount of time before it continues the activation so as to not consume an N_Port ID before a previously-active I/O port can be re-activated. An entry in the priority list is deleted when it is found during I/O port activation, and it is removed after some expiration time.
Further, it is possible to define characteristics for a virtual adapter. For example, it is possible to define certain performance characteristics in order to balance between the virtual adapters that share the same physical N_Port 17 based on the performance needs of each OS instance 21 a using the virtual adapters; e.g. a “high bandwidth” could define the use of bigger memory buffers by the AVE 30 in order to increase the bandwidth for a virtual adapter; “low bandwidth” could define the use of small memory buffers by the AVE 30 in order to decrease the bandwidth for a virtual adapter.
The separate storage device 14 does not need to be directly attached to the computer system 10 . It can also be attached to another computer system that provides indirect access to this storage device 14 via a network service for example.
This invention is preferably implemented as software, a sequence of machine-readable instructions, especially as so-called firmware executing on one or more hardware machines that controls and monitors these hardware machines and is often used to implement well-defined interfaces to the hardware, which other programs (especially operating systems) can use.
While a particular embodiment has been shown and described, various modifications of the present invention will be apparent to those skilled in the art. | The present invention relates to a method, a computer program product and a system for managing virtual instances of a physical port attached to a network. The method is based on the Fiber Channel N_Port virtualization for a physical Fiber Channel N_Port. Multiple virtual Fiber Channel adapters share a single physical N_Port among multiple operating system instances. The invention discloses means for the automatic and persistent generation and administration of unique Worldwide Port Names needed for the N_Port virtualization. | 7 |
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever.
1. Field of Invention
The present invention is directed to a computer-based method and apparatus for performing symbolic calculations, and in particular, for performing symbolic calculations in real-time.
2. Background of the Invention
Present computer controlled systems allow users to enter equations, including symbolic equations, in documents on a computer system and to perform calculations using these equations. Specialized computer systems exist for performing mathematical and statistical calculations. In these systems, the document on which the equations are entered can be considered to be a white board. The equations are entered by a user on the white board (i.e., the open document displayed on the computer screen), using known graphical user interfaces, such as, for example, the user interface of Microsoft, Inc's Windows operating system. A user can enter equations in the form that the user would write such equations on the white board, using common mathematical notations, rather than in the form of equations in programing languages or spreadsheets.
A system illustrative of current computerized mathematical symbolic programs is the Mathcad system, version 3.1 for Windows, by MathSoft, Inc., of Cambridge, Mass.
Prior art computerized mathematical systems allow entry and editing of equations in documents displayed on a computer screen. These documents can be displayed, printed and saved as files in a computer memory. It is known in such systems to automatically link and interpret related equations. The intelligent editor provided by current systems can understand and interpret equations as if a human mathematician, for example, by reading and interpreting a series of equations displayed on the screen from left to right and then top to bottom. The system links related equations. For example, if the user enters the equation
x:=5 (1)
on a document on a screen and then enters the equations
y:=x-1 (2)
2*y= (3)
the system would automatically display the result for equation (3), i.e., "8", by determining that equation (3) needs the value of y, which is calculated at equation (2), which in turn needs the value of x, calculated at equation (1). Accordingly, the system understands the mathematical relationships between equations (1) to It is known in existing systems to provide "live" document capabilities. When a change is made to a variable in a live document, all related equations are also updated in real-time. For example, if the user edits equation (1) above, using graphical user interface techniques, so that equation (1) now reads
x:=4 (1)
then equations (2) and (3) are automatically recalculated in real-time, and an new result for equation (3) is automatically displayed in the document. A document that allows for real-time recalculation of related equations in a document is known as a live document. The module of existing systems that links related equations can be called an expression compiler.
It is noted for clarity that the equation reference numbers, e.g., "(1)" are not displayed in the live document and are included in this patent application for ease of reference to equations. In a live document, the computer system "knows" the relationship between related equations. A user reads the equations on a live document as the user would read equations written on a white board. When a user updates an equation, the user can, for example, place the cursor on the part of the equation that the user wishes to update, and add and delete variables, expressions and values in the equation. Live documents, and editing thereof, are explained in detail in the Mathcad 3.1 User's Guide Windows Version, published by Mathsoft, Inc. of Cambridge, Mass., and which is expressly incorporated herein.
Existing systems also include a symbolic algebra engine ("SAE"), also known as a symbolic processor. A SAE allows a user to undertake symbolic manipulation of equations. For example, if the user enters onto the live document the equation
(x+1).sup.3 ( 4)
and then actives the SAE, for example, by selecting the "evaluate symbolically" command from the "Symbolic" menu of commands, then the system will display immediately underneath the above equation the expanded equation
x.sup.3 +3x.sup.2 +3x+1 (5)
Other symbolic calculations that can be performed on equations include solving an equation for a variable, integrating and equation, simplifying an equation, factoring an expression and the like. However, present systems do not perform "live" document functions on symbolic equations.
For example, in existing systems, equations are passed to the SAE as text, are processed by the SAE, and the results are returned for display on the document. If an equation on which a symbolic function has taken place is modified, then the result of the symbolic function performed on that equation is not modified. Thus, in the above example, if equation (4) is changed to read
(x+1).sup.4 ( 4)
then equation (5), the result of the expansion of equation (4), is not changed. A user must reactivate the SAE, and request that the SAE expand equation (4) again. the document will then display the expansion under equation (4). However, the previous expansion of equation (4), i.e., equation (5), will still be displayed in the document as shown above, unchanged.
Moreover, existing systems do not allow symbolic manipulation of equations where relevant and needed information to the symbolic manipulation is contained in other related equations. For example, suppose the user enters the equations
n:=2 (5)
(y.sup.n -1) (6)
and then the user requests that the SAE factorize equation (6), the SAE of existing systems will not be able to do so--the SAE does not know that n was given a value in equation (5). Accordingly, existing systems do not allow the "live" document features to be used when performing symbolic manipulation of equations.
In existing systems, the SAE is separate from the editor that allows entry of equations and the expression compiler that creates linkages between related expressions. Accordingly, the SAEs of existing systems can merely take expressions out of the document in use (and accordingly, out of the context in which the expression is placed), perform the symbolic manipulation, and return the result to the document. There are no dynamic links between an expression and the result of the symbolic manipulation of the expression--when the subject expression is modified, the resultant symbolically manipulated expression is not automatically symbolically recalculated.
Accordingly, there is a need for computerized systems that can perform symbolic manipulations in realtime in a live document.
SUMMARY OF THE INVENTION
The present invention provides for real-time symbolic manipulation of equations and expressions in computerized mathematics document system.
A user can enter expressions and equations into a processor controlled by means of a computer program. The expressions and equations can be displayed on a computer screen, or other output device, as if the computer screen was a white board, and the expressions and equations can be manipulated using graphical user interface commands. By using a specially designated symbolic equal sign as part of an equation, the present invention can perform symbolic manipulation on the equations and expressions that have been entered by the user.
According to the present invention, when required by a user, equations are manipulated symbolically rather than numerically. Related equations are linked so that the symbolic relationship between expressions and variables in an equation can be taken into account in the symbolic manipulation of an equation. When an equation or expression is updated or modified by the user, all equations that include the specially designated symbolic equal sign, together with all related equations to which they are linked, are automatically re-calculated (i.e., symbolically manipulated again) in real-time.
Thus, the present invention provides for live symbolics in a computerized mathematical document system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram on exemplary hardware for the present invention.
FIG. 2 is diagram of the structure of the modules of the present invention.
FIGS. 3a and 3b are representations of data structures of the present invention.
FIGS. 4 to 8 are example screen displays produced by the present invention.
DETAILED DESCRIPTION
Turning now to the drawings, and initially FIG. 1, there is illustrated in block diagram form exemplary hardware that can be used in conjunction with the present invention. A processor 2, such as, for example, an IBM brand compatible personal computer with a 486 Intel chip. The processor 2 is coupled to a memory 4, such as a hard disk drive, that stores a computer program that is executed by the processor 2 to control and coordinate the method of the present invention. Data that is manipulated by the processor 2 can be stored in the memory 4. According to the present invention, the data is stored as a document. An input device 6, such as a keyboard and a mouse, are coupled to the processor 2 for receiving instructions and equations from a user. An output device 8, typically a computer monitor or CRT, is coupled to the processor 2 for displaying the document that the user is currently creating and editing.
Turning now to FIG. 2, there is illustrated in block diagram form the main components of the present invention. A user enters an expression via the input device 6 to the smart editor 10 of the present invention. Assuming that the live symbolics feature of the present invention is not turned on, the following takes place. The editor 10 creates an expression based upon the user's input and places the expression in the open document 12. Typically, the expression is placed in the document 12 at the point identified by the user's cursor position. The document 12 is displayed to the user on an output device 8. (The instructions entered by the user to create and edit expressions are fully set forth in Mathcad 3.1 User's Guide Windows Version, published by Mathsoft, Inc. of Cambridge, Mass.
The expression entered by the user is sent by the editor 10 to an expression compiler 14. The expression compiler determines if this is a new expression or an update of an existing expression. If it is a new expression, the expression compiler 14 creates a new node in a numerical dependency graph 16. The numerical dependency graph 16 is a linked list data structure (coded in the "C" programming language) that stores all entered expressions and the relationship between expressions. The numerical dependency graph 16 can be thought of as a directed acyclic graph where the nodes represent expressions and the arcs represent variables that are numeric. For example, if the expression entered was "n:=2", then the expression compiler 14 calculates, in conjunction with a numerical computational engine 18, the value of the expression (in this case, "n=2"), and creates a node in the numerical dependency graph 16, where the node has the value 2, and the arc coming from the node as a value of "n". If the expression entered was "y:=2+3", then the value of y is calculated as 5 and substituted in the expression.
When the user enters a new expression, the expression compiler 14 looks up the numerical dependency graph 16 for other expressions that may give numerical values to variables or expressions used in the new expression. If so, the expression compiler 14 imports, into the new expression, that value from the corresponding node(s) in the graph 16 and calculates (as best as possible) the value for the new expression. Where the newly entered expression relies on values from other expressions, the expression compiler 14 generates a node for the new expression that depends from the nodes representing the expressions relied upon. When the user edits (or modifies) an expression that has been previously entered, the editor 10 modifies the expression and places the modified expression in the correct location in the document 12. The expression compiler 14 generates a new value of the modified expression. Next, the expression compiler 14 automatically goes down the linked list that represents the numerical dependency graph and marks as "out of date" all expressions that depend on the modified expression. Next, each node that has been marked out of date in turn recalculates itself (with the assistance of the numerical computational engine 18). In performing each recalculation, the node looks up the graph 16 to find the new values of an recalculated nodes (i.e., expressions). When a node is recalculated, the editor automatically updates the document 12. Accordingly, the document 12 is always the most current representation of the nodes of the numerical dependency graph 16. The numerical computational engine 18 has access to a numerical library 20 that is a library of subroutines for performing numerical computations.
In further detail, when an expression is entered by a user that requires calculation, the expression compiler 14 generates a "program" that determines how the expression is to be calculated to give a result. Where variables in the expression have been previously calculated, reference is made to these expressions. The numerical computational engine 18 executes such programs to evaluate expressions. If the user enters an equal sign (i.e. "=") after an expression, then the expression compiler generates a display "function" that specifies that the result of the expression is to be displayed alongside the expression on the document 12. These programs and functions can be stored in the link list of the numerical dependency graph 16. When an expression is modified, the expression compiler 14 will re-generate a new program for that expression, have the numerical computational engine 18 recalculate the result of the expression, and mark and have updated all expressions that reference the modified expression. For expressions that are updated because they depend upon changed expressions in the graph 16, a new program expressing the expression is generated. Thus, to be precise, it is programs representing expressions (not expressions) that are generated, re-generated and executed.
Accordingly, the document of the present invention can be regarded as a "live document".
In the representative embodiment of the present invention, the editor 10, expression compiler 14, numerical dependency graph 16 and numerical computational engine 18 are implemented in the "C" programming language.
Coupled to the editor 10 of the present invention, and operating independently from the expression compiler 14, is a symbolic algebra engine ("SAE") 22. In the representative embodiment of the present invention, the SAE is a version of the Maple symbolic engine developed by Waterloo Maple Software, Inc. of Ontario, Canada. The user can mark an expression in the document 12, for example, by placing the cursor on the expression and clicking a button on the mouse 6. The user can then turn on the SAE, and enter a symbolic command. Examples of symbolic commands include EVALUATE SYMBOLICALLY, SIMPLIFY, EXPAND EXPRESSION, FACTOR EXPRESSION, SOLVE FOR VARIABLE, INTEGRATE ON VARIABLE, DIFFERENTIATE ON VARIABLE, CONVERT TO PARTIAL FRACTION, TRANSPOSE MATRIX, INVERT MATRIX, DETERMINATE OF MATRIX. The editor 10 takes the expression selected by the user, passes it to the SAE 22, which performs the requested symbolic command. The result is returned to the editor 10 for insertion into the document 12. However, because the SAE 22 is independent from the expression compiler for the reason that the expression compiler 14 can only handle numerical (not symbolic) expressions, the SAE 22 cannot perform live symbolic functions. An expression returned to editor 10 by the SAE 22 and inserted in the document 12 is not automatically updated when the expression that was selected by the user and was passed to the SAE 22 is later modified.
The live symbolics feature of the present invention in implemented by means of a symbolic dependency graph ("SDG") 26 and a live symbolic interpreter 24. The user must activate the live symbolics feature of the present invention by entering a command to do so. Once the live symbolics feature is activated, each expression that is entered by the user is passed by the editor 10 to both the expression compiler 14 (for numerical calculations) and to the SDG 26 (for symbolic processing).
Conceptually, each time a new expression is entered, a node is created in the SDG 26. This node represents the expression, as an expression. No calculation step takes place, and there is no substitution of values for variables. Each expression is treated as an symbolic expression, not a numerical expression. Where dependencies exist between expressions, this is reflected in the structure of the SDG 26.
When requested by the user, the live symbolic interpreter 24 will take an expression nominated by the user and perform a symbolic command specified by the user. The symbolic command is specified by the user in the representative embodiment by placing a designated symbolic equals sign (e.g., →) after an expression that the user wishes to have symbolically processed. It is at this stage that the live symbolic interpreter 24 analyzes the meaning of each expression, substitutes values, variable, and other expressions in dependent expressions (as specified by the SDG 26). This step can be regarded as assembling definitions for the variables and expressions in the selected expression. The live symbolic interpreter 24 will then take the selected expression and pass the selected expression to the SAE 22 for processing. The resultant expression is returned via the live symbolic interpreter 24 to the SDG 26, which is updated by adding the returned expression to the SDG 26. The returned expression is then forwarded to the editor 10 so that the document can be updated by including the returned expression.
Because the expression that is the result of the symbolic interpretation is inserted in the SDG 26, each time an expression in the SDG 26 ms modified or updated, the live symbolic interpreter 24 determines if any expression that relies upon the modified/updated expression is affected, and if so, passes the expression to the SAE 22 for processing as above.
In contrast to the numerical dependency graph 16, where the nodes represent programs that calculate numerical values for entered expressions and where the arcs are variable names that represent the corresponding numerical variables, the nodes of the SDG 26 represent expressions qua expressions and the arcs represent variable names that represent the corresponding expressions. For example, if the user enters the following expressions:
x:=5;
y:=x-1;
and then entered the expression
(x+1).y=
(the "="sign in the representative embodiment of the present invention signifying that this is to be evaluated as a numerical expression,) then the numerical dependency graph 16 of FIG. 3a would be produced. The result 24 would be displayed However, if the user instead entered the expression
(x+1).y→
(the "→" sign signifying that the expression is to be evaluated symbolically), then the SDG 26 of FIG. 3b would also be produced. It is noted that it is not the order that the expressions are entered by the user that determines the hierarchy of graphs, but rather, the mathematical meaning as to where the expressions are placed in the document. In FIG. 3b, if the node representing the expression (y:=x-1) is edited by the user to read (y:=x-2), node 50 would change, but would not look up the graph and regenerate unless requested to do so by node 52. It is further noted that the arcs in FIG. 3b pass expressions, not numerical results. Accordingly, arc 49 passes the expression "5", not the numerical value 5. In contrast, if the same modification was made to the graph of FIG. 3a, then the expression therein would be immediately numerically recalculated.
In the representative embodiment of the present invention, the SDG 26 and the live symbolic interpreter 24 are implemented using the expert system shell known as CLIPS (C Language Integrated Production Systems), developed by NASA's artificial intelligence section. CLIPS acts like a separate and independent processor. The live symbolic interpreter 24 is implemented as a set of expert system rules according to CLIPS notation. These rules are set forth in Appendix A attached hereto and are expressly incorporated herein by reference. The expressions of the SDG 26 are facts (or tokens) that can be processed by the rules of the live symbolic interpreter 24. An example of a fact may be
(NODE AT 527 607234)
(607234 defs "x")
which states that the node for expression "x" is at line 527, having a generated identification number of 607234. This notion is easily understood by those familiar with the CLIPS notation. CLIPS is a public domain program.
Accordingly, when an expression is entered by the user, the editor 10 places the expression in the SDG 22 in the form of a complex CLIPS fact. The editor 10 includes code programmed in the C programming language to perform this function. If the expression includes a "→" sign, the live symbolic interpreter 24 causes a symbolic evaluation of the expression to be performed. In doing so, the live symbolic interpreter 24 examines the SDG 22 to determine on what expressions the subject expression depends. For example, if the subject expression is "x=y→", then the live symbolic interpreter 24 determines, by examining the SDG 22, what are the symbolic values of "x" and of "y". The live symbolic interpreter 24 takes the symbolic definitions of x and y and the subject expression, a passes them to the SAE for evaluation. The resultant expression is displayed as an expression.
Of course, the dependencies of expressions can be very complex, and the general principals discussed above are able to take into account the complexity of the mathematics.
Turning now to FIG. 4, there is illustrated at screen display of an example document 12 generated by the present invention. Because the document 12 is to represent a white board, both expressions and text can be included in the document. Parts of the document that comprise expressions are known as "math regions." Here, the text is included for explanatory purposes. FIG.4 shows examples of how a user may use the "→" symbolic operator of the present invention, which, in the representative embodiment, is entered by the user by pressing the "control" key and the "period" key. The "→" operator applies to the whole of the expression of its left hand side, and the result of the symbolic manipulation is on the right hand side.
FIG. 5 is another example, showing the use of keywords. Keywords modify the operation of the "→" operator. In the representative embodiment, there are five keywords. The keyword "simplify" simplifies the expression, performing arithmetic, canceling common factors and using basic trigonometric and inverse function identifiers. The keyword "expand" expands all powers and products of sums in the selected expression. The keyword "factor" factors the selected expression into a product, if the entire expression can be written as a product. The keyword "assume" causes the present invention to treat the variable which follows as a variable even though it may have numerical values assigned to it. It can also be used to specify constraints to be used in evaluation of the expression. The keyword "complex" causes the present invention to carry out symbolic evaluation in the complex domain. The result will usually be in the form a+i.b.
It is noted that in the representative embodiment that keywords can be entered directly on a document, as if writing on a white board, or can be selected from a "Symbolic" menu on the menu bar of the graphical user interface of the present invention. FIG. 6 shows use of the "Assume" keyword. FIG. 7 shows use of the "complex" keyword.
FIG. 8 illustrates creating expressions that depend upon a symbolic result. By using the symbolic equals sign in definitions, the user can create other definitions that depend on a symbolic result. The additional definitions will change whenever the symbolic result changes. Thus, the changing of a function definition changes the result of all expressions that use that function. | A mathematical document editor that can perform live symbolic calculations. The mathematical document editor is capable of placing mathematical expressions at any position on a computer screen, that represents a printed document. A symbolic dependency graph is maintained such that it always reflects the mathematical dependencies on the computer screen. Any expression which includes a symbolic evaluation operator is evaluated by a symbolic algebra engine, taking into account all the definitions and constraints upon which the expression depends. If an expression is modified, introduced or deleted, the symbolic dependency graph is used to determine which expression containing the symbolic evaluation operator need to be modified. The present invention ensures that the document is `up to date` in the sense that all expressions, including those requiring symbolic calculations, are consistent with all antecedent expressions upon which they depend. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a control system for an automatic clutch interposed between an engine and a transmission of a motor vehicle, and particularly to a system for controlling the clutch at engine braking.
Recently, the automatic clutch is employed in the motor vehicle for smoothly transmitting power of the engine to an automatic transmission. The automatic transmission is controlled by a control system for controlling clutch torque.
There is provided an automatic transmission having a high reduction ratio range (Ds-range) for effecting the engine braking at any speed of the transmission. When the Ds-range is selected during down-hill driving, engine braking is effected by the high reduction ratio of the transmission. Thus, safe driving is insured. However, it is necessary that the vehicle is on a road having as a high a friction coefficient μ as a dry road for the engine braking.
If the Ds-range is selected during driving on such a slippery surface of the road as a snowy road having a low friction coefficient μ, the large engine braking force becomes larger than the gripping force of the tires for the road surfaces so that the corresponding vehicle wheel is locked. Since the wheel skids, the wheel speed is rapidly reduced, resulting in a loss of steering the vehicle.
In the transmission having the automatic clutch, the clutch is temporarily disengaged to reduce the engine braking force. Thereafter, when the vehicle enters a dry road zone, the gripping force of the tires is restored. However, since the clutch is disengaged, the engine braking is not effected. Therefore, it is necessary to quickly control the clutch in dependency on the gripping force.
Japanese Patent Application Laid-Open 61-129330 discloses an automatic transmission system in which if the difference between the rotating speeds of the driving wheels exceeds a predetermined value, the clutch torque of a clutch is reduced.
In the system, the clutch is controlled when the wheels slip at starting or at acceleration. Therefore, the system is not available for control at the engine braking.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system for an automatic clutch which is properly controlled in dependency on gripping conditions of tires at the engine braking, thereby insuring safe driving and steerability of the vehicle as well as the engine braking effect.
According to the present invention, there is provided a control system of an automatic clutch for transmitting power of an engine to a driving wheel of a motor vehicle, comprising a continuously variable transmission interposed between the clutch and the driving wheel, a throttle sensor for detecting an opening degree of a throttle valve and for generating a throttle opening degree signal, a select position sensor provided on the transmission for detecting a select position of a driving range and for producing a select position signal, an engine speed sensor mounted on the engine for detecting an engine speed and for producing an engine speed signal, an accelerator switch for detecting an accelerator position and for generating an accelerator signal, a vehicle speed sensor for sensing a driven pulley speed of the continuously variable transmission and for generating a vehicle speed signal and, clutch control means responsive to the vehicle speed signal, the select position signal and the accelerator signal for controlling the clutch.
The system comprises tire grip determining means responsive to the vehicle speed signal for determining whether the wheel is holding road surface without slipping or not and for producing a grip signal, engine brake detecting means responsive to the accelerator signal and the select position signal for detecting an engine brake condition and for generating an engine brake signal, and correcting means responsive to the grip signal and the engine brake signal for correcting clutch current in the control means so as to maintain an optimum control of the clutch in dependency on holding condition of the road surface.
In an aspect of the invention, the correcting means operates to disengage the clutch when the holding condition decreases, and to engage the clutch when the holding condition increases.
The other objects and features of the present invention will become understood from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic illustration of a system for controlling an electromagnetic clutch of a motor vehicle according to the present invention;
FIGS. 2a and 2b show a block diagram of a control unit of the system;
FIG. 3 is a flowchart showing an operation of the system at engine braking;
FIG. 4 shows graphs showing a time chart of an operation for rapidly restoring a wheel speed;
FIG. 5 shows the graphs showing the time chart of the operation for slowly restoring the wheel speed;
FIG. 6 is a schematic illustration showing a second embodiment having a system for controlling an electromagnetic clutch with a hydromechanically controlled continuously valuable transmission;
FIG. 7 shows a block diagram of a control unit of the second embodiment;
FIG. 8 is a schematic illustration showing a third embodiment having the system for controlling a friction clutch; and
FIGS. 9a and 9b show a block diagram of a control unit of the third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, showing a control system for an electromagnetic clutch for a continuously variable transmission, a crankshaft 2 of an engine 1 is operatively connected to an electromagnetic powder clutch 3 for transmitting power of the engine 1 to an electrohydrostatic controlled continuously variable transmission 10 through a selector mechanism 9. Output of the transmission 10 is transmitted to axles 18 of vehicle driving wheels 19 through an output shaft 13, a pair of intermediate reduction gears 16, an intermediate shaft 13a, and a differential 17.
The electromagnetic power clutch 3 comprises an annular drive member 3a connected to the crankshaft 2 of the engine 1, a driven member 3b secured to an input shaft 11a of the transmission 10, and a magnetizing coil 3c provided in the driven member 3b. Powdered magnetic material is provided in a gap between the drive member 3a and the driven member 3b. When the magnetizing coil 3c is excited by the clutch current, the driven member 3b is magnetized to produce a magnetic flux passing through the drive member 3a. The magnetic powder is aggregated in the gap by the magnetic flux and the driven member 3b is engaged with the drive member 3a by the powder. On the other hand, when the clutch current is cut off, the drive and driven members 3a and 3b are disengaged from one another.
In the transmission 10, the selector mechanism 9 is provided between the input shaft 11a and a main shaft 11. The selector mechanism 9 is provided with a synchromesh mechanism comprising gears, a hub, and a sleeve for connecting the input shaft 11a and the main shaft 11.
The continuously variable transmission 10 has the main shaft 11 and the output shaft 13 provided in parallel with the main shaft 11. A drive pulley 12 provided with a hydraulic cylinder 12a is mounted on the main shaft 11. A driven pulley 14 provided with a hydraulic cylinder 14a is mounted on the output shaft 13. A drive belt 15 engages with the drive pulley 12 and the driven pulley 14. Hydraulic cylinders 12a and 14a are communicated with an oil hydraulic control circuit 28 through passages 28b and 28a, respectively. The cylinder 12a is supplied with a primary pressure Pp by an oil pump P from an oil reservoir through a line pressure control valve LC and a transmission ratio control valve TR. The cylinder 14a is applied with a line pressure Ps from the pump P through the control valve LC. The hydraulic control circuit 28 is responsive to vehicle speed, engine speed and a throttle valve position for controlling the amount of oil supplied to the cylinders 12a and 14a. The pulleys 12 and 14 are operated by the cylinders 12a and 14a so that running diameter of the belt 15 is varied to infinitely change the transmission ratio (i).
An electronic control system for the electromagnetic clutch 3 and the transmission 10 has an engine speed sensor 22, and rotating speed sensors 24 and 25 for respectively sensing rotating speeds of the drive pulley 12 and the driven pulley 14. A selector lever connected to the selector mechanism 9 is provided with a select position sensor 20 for sensing operational positions of the transmission 10. An accelerator pedal switch 21 is provided for sensing depression of an accelerator pedal, and a throttle position sensor 23 is provided.
Output signals of the sensors 22-25 and pulses of the switches are applied to an electronic control unit 27 which produces a clutch current control signal supplied to the clutch 3 and a control signal for controlling the transmission ratio (i) and a line pressure control signal supplied to the control circuit 28.
Referring to FIGS. 2a and 2b showing the control unit 27 of FIG. 1, a transmission ratio changing speed control section 30 comprises an actual transmission ratio calculator 32 to which output signals N P and N S of the sensors 24, 25 are fed to produce an actual transmission ratio i in accordance with i=N P /N S . The transmission changing speed control section 30 further has a desired transmission ratio calculator 33 where a desired transmission ratio id is calculated in accordance with a desired drive pulley speed Npd, which is derived from a table, and the driven pulley speed N S . The actual transmission ratio i and the desired transmission ratio id are fed to a transmission ratio changing speed calculator 34 in which a desired transmission ratio changing speed (rate) di/it is obtained in accordance with the difference between the actual transmission ratio i and the desired transmission ratio id. The actual transmission ratio i is controlled to converge to the desired transmission ratio id. A duty ratio signal dependent on the desired transmission ratio changing speed di/dt is applied to a solenoid operated valve 35. The valve 35 is provided in the hydraulic circuit, for shifting a spool of the transmission ratio control valve TR to control the transmission ratio i.
The transmission 10 has a driving position (D-range), a high engine speed driving position (Ds-range), a neutral position (N-range), a reverse driving position (R-range), and a parking position (P-range). The select position sensor 20 detects these positions and produces a select position signal which is supplied to the desired transmission ratio calculator 33. When a Ds-range select signal is supplied to the calculator 33, the desired transmission ratio id is set to a lower speed state than a predetermined transmission ratio.
A line pressure control section 31 is applied with an engine speed signal Ne from the sensor 22 and throttle opening degree θ from the sensor 23 to obtain an engine torque Te. A desired line pressure Psd is obtained in accordance with the engine torque Te and the actual transmission ratio i. A duty ratio signal corresponding to the desired line pressure Psd is applied to a solenoid operated valve 36. The valve 36 is provided in the hydraulic circuit, for shifting a spool of the line pressure control valve LC to control the line pressure.
A system for controlling the electromagnetic clutch 3 is described with reference to FIG. 2b. The control unit comprises a clutch control section 40 applied with signals from the select position sensor 20, accelerator pedal switch 21, engine speed sensor 22, throttle position sensor 23, and a vehicle speed V obtained in accordance with the driven pulley speed N S . The clutch control section 40 has a reverse excitation mode determining section 41 applied with the engine speed signal Ne of the sensor 22 and drive position signals of the select position sensor 20. When the engine speed Ne is at an idling speed, or the selector lever is at the neutral position (N-range) or the parking position (P-range), the reverse excitation mode determining section 41 produces a reverse excitation signal which is applied to an output determining section 44, so that a small reverse current flows in the coil 3c of the clutch 3 through a clutch current control section 45 to release the clutch completely.
A clutch current mode determining section 42 is applied with the signals from the reverse excitation mode determining section 41 and the accelerator pedal switch 21, and a vehicle speed signal V from driven pulley speed sensor 25 for determining driving conditions such as starting mode to produce output signals. The output signals are applied to a start mode providing section 43a, a drag mode providing section 43b, and a clutch lock-up engage mode providing section 43c.
The start mode providing section 43a decides the clutch current of starting characteristics dependent on the engine speed Ne at ordinary start or at closing of a choke valve or at the operation of an air conditioner. The starting characteristics are corrected by the signals, i.e., the throttle valve opening degree θ, the vehicle speed V, and the driving positions of D-range, Ds-range and R-range.
The drag mode providing section 43b decides a small drag current when the accelerator pedal is released at a low speed in each drive position for providing a drag torque to the clutch 3 for reducing clearance formed in the transmission 10 and for smoothly starting the vehicle. At the D-range, the clutch current is set to zero until a time immediately before the vehicle stops, thereby insuring a coasting effect of for the vehicle.
The clutch lock-up engage mode providing section 43c decides a lock-up current in response to the vehicle speed V and the throttle opening degree θ at each drive position for entirely engaging the clutch 3. The output signal of the sections 43a, 43b and 43c are applied to the clutch current control section 45 through the output determining section 44 to control the clutch current.
The control unit 27 has a system for controlling the electromagnetic clutch 3 in the Ds-range at engine braking.
The control unit has an engine braking mode detector 47 applied with output signals from the select position sensor 20 and the accelerator pedal switch 21. The detector 47 detects the engine braking mode and produces an engine braking mode signal, when the accelerator pedal is released in Ds-range driving. The engine braking mode signal is supplied to a clutch engagement and disengagement correcting section 50.
The control unit further has a tire grip reduction determining section 48 and a tire grip restoration determining section 49 to which a wheel speed Vw represented by the driven pulley speed Ns is applied. The tire grip reduction determining section 48 calculates an acceleration dVw/dt of the wheel speed Vw and detects a deceleration -dVw/dt when the acceleration dVw/dt is smaller than zero (dVw/dt<0) and compares the deceleration -dVw/dt with a predetermined set value a. When the deceleration -dVw/dt is larger than the set value a (-dVw/dt≧a), the determining section 48 determines that the grip of the tire is reduced. The tire grip restoration determining section 49 calculates an acceleration dVw/dt of the wheel speed Vw which is compared with a predetermined set value b. The determining section 49 determines that the grip of tire is restored when the acceleration dVw/dt is larger than the set value b (dVw/dt≧b). The respective determining signals are supplied to the correcting section 50.
When the grip reduction determining signal from the section 48 is supplied to the correcting section 50 in the engine braking mode, the section 50 operates a timer 51 to set a predetermined clutch disengagement time Toff and produces a clutch disengagement signal which is supplied to the clutch current control section 45. On the other hand, when the grip restoration determining signal from the section 49 is supplied to the correcting section 50, the section 50 produces a clutch engagement signal which is supplied to the control section 45.
The operation of the system will be described hereinafter.
When the accelerator pedal is depressed at the D-range, the clutch current mode determining section 42 applies a signal to the start mode providing section 43a. A start mode control signal is fed to the clutch current driving section 45 through the output determining section 44 so that a clutch current suitable for starting the vehicle flows in the coil 3c of the clutch 3. When the vehicle speed V reaches a predetermined speed, a signal is supplied to the lock-up engage mode providing section 43c so that a large lock-up current for completely engaging the clutch flows to lock up the clutch 3. When the accelerator pedal is released at a predetermined low vehicle speed, a signal is supplied to the drag mode providing section 43b so that a small drag current flows in the coil 3c to disengage the clutch 3, thereby preventing the engine from stalling. The small drag torque is produced to reduce mechanical play formed in the transmission. When the P-range or N-range is selected at a low engine speed, the reverse excitation mode determining section 41 produces a reverse excitation signal which is applied to the output determining section 44 so that a small reverse current flows in the coil 3c to excite the coil in reverse. The residual magnet of the clutch 3 is accordingly removed to completely disengaged the clutch 3.
When the clutch 3 is engaged, the power of the engine 1 is transmitted to the driving wheels 19 through the continuously variable transmission 10 controlled by the transmission changing speed control section 30 and the line pressure control section 31 to start the vehicle.
The line pressure control section 31 produces the duty ratio signal corresponding to the desired line pressure which is applied to the solenoid operated valve 36 for controlling the line pressure.
The transmission ratio changing speed control section 30 controls the desired transmission ratio id in the entire range of the transmission at the D-range. At the stop and the starting of the engine, the desired transmission ratio id is determined at the maximum transmission ratio (low speed state). As the vehicle speed increases with increase of the primary pulley speed Np, the desired transmission ratio id reduces. The transmission ratio changing speed signal di/dt obtained in accordance with the desired transmission ratio id and the actual transmission ratio i is supplied to the solenoid operated valve 35 for increasing the primary pressure Pp exerted on the primary pulley 12. The belt 15 is shifted to the side of the primary pulley 12 to increase the diameter of the pulley 12, thereby upshifting the transmission to a smaller transmission ratio (high speed state). When the vehicle speed is reduced at deceleration, the desired transmission ratio id is set to a low speed, thereby downshifting the transmission.
When the vehicle is driven down a slope at the Ds-range by releasing the accelerator pedal, the desired transmission ratio id is controlled to a lower speed than a previous transmission ratio. Thus, the primary pressure Pp is lowered to forcibly downshift the transmission, so that the engine braking is effected.
In this state, the control of the clutch 3 is corrected in dependency on the wheel speed Vw. The correcting operation of the clutch will be described hereinafter with reference to the flowchart of FIG. 3.
At a step S2, it is determined whether the drive position is shifted to the Ds-range from the D-range or not. If there is no shift operation, the program goes to a step S3 where it is determined whether the drive position is at the Ds-range or not. If the D-range is selected, the program proceeds to a step S4 where it is determined whether the clutch 3 is disengaged or not. If not, the program proceeds to a step S5 where the clutch is normally operated. At a step S6, the timer is cleared.
To the contrary, when the Ds-range is selected at the step S2 or step S3, the program proceeds to a step S7 where it is determined whether the deceleration -dVw/dt at engine braking is higher than the set value a or not. When the vehicle is driven on the dry road, the grip of the tires is sufficiently larger than the engine braking force. Therefore, the wheel speed Vw is decelerated at a deceleration -dVw/dt lower than the set value a. Thus, the engine brake is normally effected. The program goes to the step S5 through the step S4.
However, if the road changes to a slippery road, the grip of tires reduces. Accordingly the speed of the wheels largely reduce or the wheels are locked by the engine braking. The wheel speed Vw is rapidly lowered compared with a vehicle body speed Vb at a deceleration -dVw/dt higher than the set value a as shown in FIG. 4. If -dVw/dt≧a at the step S7, the program goes to a step S8 where the clutch 3 is immediately disengaged in accordance with the clutch disengagement signal as shown in FIG. 4. Thus, the power of the engine 1 is not transmitted to the wheels 19 so that engine braking on the wheels does not take place. Accordingly, the grip of the tires is restored, thereby insuring the driving stability and steerability of the vehicle. At a step S9, the timer is set to a predetermined period Toff for disengaging the clutch. The program returns to a step S1.
When the clutch is disengaged, the wheel speed Vw is increased to lower the deceleration dVw/dt. The program goes to a step S10 from the step S7 through the step S4. At the step S10, the acceleration dVw/dt is determined in accordance with the set value b. When the vehicle is driven on the dry road from the slippery road, the grip of the tire is restored. If acceleration dVw/dt≧b, the program goes to s step S11 where the clutch is immediately engaged in accordance with the engagement signal. At a step S12, the timer is cleared. The engine 1 is connected to the wheels 19 so that the engine braking acts on the wheels at the Ds-range.
When the vehicle is still driven on the slippery road and the acceleration dVw/dt is lower than the set value b at the step S10 as shown in FIG. 5, the program proceeds to a step S13. At the step S13, it is determined whether the set time Toff has passed or not (T=0). If not, the program goes to a step S14 where the clutch is held in the disengagement state. If the set time passes, the program goes to the step S11 and the step S12. Thus, the clutch 3 is engaged to effect the engine braking as shown in FIG. 5.
Referring to FIG. 6 and FIG. 7 showing the second embodiment of the present invention, the clutch control system of the present invention is applied to a hydromechanically controlled continuously variable transmission. A detail of the hydromechanically controlled continuously valuable transmission is described in U.S. Pat. No. 4,948,370 which is hereby incorporated by reference by the applicant of the present invention. In the second embodiment, the control system is applied with a vehicle speed sensor 29 instead of the driven pulley speed sensor 25 and substitutes the output of the accelerator pedal switch 21 for the output of the throttle position sensor 23. The vehicle speed sensor detects the wheel speed Vw and supplies the wheel speed Vw to the tire grip reduction determining section 48 and the tire grip determining section 49. After that, the operation of the second embodiment proceeds in the same manner as the operation of the first embodiment.
Referring to FIG. 8 showing the third embodiment, a control system of the third embodiment has a dry-plate friction clutch 29 which is operatively connected to the crankshaft 2 of the engine 1 for transmitting the power of the engine 1 to the continuously variable transmission 10 through the selector mechanism 9.
The dry-plate friction clutch 29 comprises a flywheel 4 connected to the crankshaft 2 of the engine 1, a pressure plate 6 opposed to the flywheel 4 and secured to an input shaft 11a of the transmission 10, and a diaphragm spring 5. The diaphragm spring 5 is operated by a release lever 7 connected with a DC motor 8 as an actuator. The DC motor 8 is actuated by drive pulses, and the rotation thereof is converted into a rectilinear motion by a converting device so as to lineally shift the release lever 7. When the drive pulses are cutoff, the rotation of the DC motor 8 is stopped by a braking device provided therein to hold the release lever 7 at the position. For example, when the DC motor 8 is rotated in one direction, the diaphragm spring 5 is actuated by the release lever 7 to push the pressure plate 6 against the flywheel 4. Thus, the clutch 29 is mechanically engaged by a frictional force, thereby transmitting the output of the crankshaft 2 to the input shaft 11a. On the other hand, when the DC motor 8 is rotated in the opposite direction, the clutch 29 is disengaged. The duty ratio of the drive pulses applied to the motor 8 is variable so as to control the shifting speed.
An electronic control system for controlling the clutch 29 is described with reference to FIG. 9. The system further has a clutch position sensor 26 for detecting the position of the clutch 29 in dependency on the operation of the DC motor 8. A control unit 27' comprises a clutch control section 60 for controlling the DC motor 8 of the clutch 29. The clutch control section 60 has a clutch disengagement mode determining section 61, a clutch partial engagement mode determining section 62, and a clutch engagement mode determining section 63 which are respectively applied with signals from the select position sensor 20 and the accelerator pedal switch 21, and the vehicle speed signal from the driven pulley speed sensor 25. In the control section 60, the disengagement mode, the partial engagement mode, and the engagement mode of the clutch 29 are determined in accordance with the operations of the select lever and the accelerator pedal by the driver and the driving conditions. The respective mode signals are supplied to a desired clutch position determining section 64 where a desired clutch position Sd is determined based on the input mode signals. A desired position signal Sd is fed to a motor control section 65.
The control unit 27' is provided with an actual clutch position detector 46 to which a clutch position signal from the clutch position sensor 26 is supplied for detecting an actual clutch position S. An actual position signal S is supplied to the motor control section 65. The motor control section 65 calculates the difference ΔS between the desired clutch position Sd and the actual clutch positions S and produces a motor control signal of a duty ratio corresponding to the difference ΔS. The motor control signal is supplied to the DC motor 8 for operating the clutch 29.
The other structures are the same as the first embodiment and the same parts thereof are identified with the same reference numerals as FIGS. 1 and 2.
In the control unit 27', the signal from the clutch correcting section 50 is supplied to the motor control section 65.
Describing the operation of controlling the clutch 29, when the D-range is selected and the accelerator pedal is depressed, the clutch partial engagement mode determining section 62 determines the partial engagement mode of the clutch. The desired clutch position determining section 64 calculates the clutch position Sd in the partial engagement which is supplied to the motor control section 65. Thus, the DC motor 8 is gradually rotated in a direction to partially engage the clutch.
When the vehicle speed reaches a predetermined speed, the clutch engagement mode determining section 63 determines that the clutch 29 is to be entirely engaged.
When the clutch engagement mode is determined, the desired clutch position Sd is set at the maximum value at the section 64. Thus, the motor is further rotated and the clutch 29 is entirely engaged and held in the engagement state thereafter.
When the accelerator pedal is released at deceleration at a predetermined vehicle speed, the clutch disengagement mode is determined at the clutch disengagement mode determining section 61. The clutch desired position Sd is set at the minimum value so that the motor 8 is rotated in the reverse direction to disengage the clutch, thereby preventing the engine from stalling.
The operation of the clutch 29 at engine braking is the same as the first embodiment.
In accordance with the present invention, if the wheel speed is rapidly lowered in the engine braking effect mode, the clutch is disengaged so as to prevent the wheel speed from decreasing. Thus, driving stability and steerability are insured, thereby improving safe driving of the vehicle. When the grip of the tire is restored, the clutch is immediately engaged to effect the engine braking. Furthermore, if the wheel speed is not sufficiently restored, the clutch is operated to be engaged after a predetermined time passes. Thus, the engine braking is properly effected.
While the presently preferred embodiments of the present invention have been shown and described, it is to be understood that these disclosures are for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | A control system of an automatic clutch for a motor vehicle has a continuously variable transmission interposed between the clutch and driving wheels, a select position sensor provided on the transmission for detecting a select position of a large reduction range and for producing a select position signal, an accelerator switch for detecting an accelerator position and for generating an accelerator signal, and a vehicle speed sensor for generating a vehicle speed signal. Tire grip condition is determined in accordance with the vehicle speed signal that wheels grip a road surface without slipping. Engine braking is detected by the accelerator signal and the select position signal. The engagement of the clutch is controlled in accordance with the grip condition and the engine braking so as to maintain an optimum control of the clutch. | 5 |
This invention relates to catalyzed oxidation and reduction reactions. More particularly, this invention is directed to improved oxidation and hydrogenation reactions based upon the discovery of exceptional catalytic properties of certain solid solutions of lanthanum, strontium and chromium oxides.
Over the last two decades there has been a significant research and development effort directed to the advancement of technology for facilitating air pollution abatement. One area of focus by scientists both in industry and in educational institutions has been development of catalysts for use in catalytic converters for automotive exhaust systems. Noble metal catalysts, because of their unrivaled catalytic activity, and in spite of their high cost, have enjoyed wide commercial use in pollution abatement systems in the automotive industry. Notwithstanding significant research expenditures, there has been little success toward the development of catalysts or catalyst systems that can compete with noble metal catalyst with respect to specific activity and resistance to sulfur poisoning. There is a continuing need for the development of alternative catalysts and catalytic systems for applications where catalysts of high specific activity are desirable to promote oxidation or hydrogenation reactions.
The use of metal oxides as catalysts for oxidation and reduction reactions are known in the art. However, metal oxide catalysts are very susceptible to sulfur poisoning. Moreover, they are susceptible to sintering at elevated temperatures. Prior to the discovery underlying the present invention, no metal oxide catalyst was recognized to have specific activity and sulfur poisoning resistance comparable to that exhibited by noble metal-based catalyst systems.
Therefore, it is one object of this invention to provide lanthanum strontium chromite compositions adapted for use as catalysts for oxidation and hydrogenation reactions at elevated temperature.
Another object of this invention is to provide a non-sintering metal oxide catalyst which not only has a specific activity comparable to noble metal catalysts, but also has exhibited good resistance to sulfur poisoning.
It is another object of this invention to provide an improvement in metal oxide catalyzed oxidation reactions.
One further object of this invention is to provide an improvement in metal oxide catalyzed hydrogenation reactions.
It is still another object of this invention to provide a process for treating exhaust gases from combustion systems by utilizing lanthanum strontium chromites to catalyze reactions of said gases to reduce levels of air polluting components.
It has been discovered that solid oxide solutions of the formula La 1-x Sr x CrO 3- ∂ (where ∂ is a deviation from stoichiometry and x is greater than zero and less than 0.5), have been found to have high specific activity as catalysts for oxidation reactions. Those same lanthanum strontium chromites have also been found to serve as effective catalysts for hydrogenation reactions, for example, hydrogenation of propylene at >200° C. Solid solutions of the composition La 0 .8 Sr 0 .2 CrO 3- ∂ and La 0 .7 Sr 0 .3 CrO 3- ∂ have been found to have a superior resistance to sintering. Further, they rival the noble metal catalysts in terms of specific activity and immunity to sulfur poisoning. The above defined lanthanum strontium chromites are used in accordance with the improvement of this invention as substitutes for noble metal catalysts for oxidation and hydrogenation reactions, particularly in applications requiring high specific catalyst activity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents light-off temperature curves of carbon monoxide oxidation for four catalyst compositions.
FIG. 2 presents light-off temperature curves of propylene hydrogenation for three catalyst compositions.
DETAILED DESCRIPTION OF THE INVENTION
There is provided an improved method for conducting oxidation and hydrogenation reactions in the presence of a metal oxide catalyst. Solid oxide solutions of the formula La 1-x Sr x CrO 3- ∂, wherein x is greater than zero and less than about 0.5, exhibit specific catalyst activities comparable to those exhibited by noble metal catalysts. The terms "specific activity" or "specific catalyst activity" as used in this description refers to moles reacted per unit time per exposed surface area. Preferred solid oxide solutions in accordance with the present invention have a stoichiometry represented by the above formula wherein x is about 0.1 to about 0.4.
The lanthanum strontium chromite catalysts useful in accordance with this invention can be prepared by any of a wide variety of art-recognized techniques for forming solid metal oxide solutions. Thus, for example, the component metal oxides can be combined in the desired stoichiometric proPortions, pelletized and sintered at temperatures ranging between about 900° C. to about 1100° C., optionally followed by cycles of grinding, pelletizing and sintering to ensure complete reaction and solid solution homogeneity.
The present lanthanum strontium chromite catalysts can also be prepared as a coating or film on refractory substrates, preferably refractory substrates exhibiting a surface area of greater than 0.5 m 2 /gram. Exemplary of refractory substrates suitable as carriers for films or coatings of the lanthanum strontium chromite useful in accordance with the present invention include quartz, porcelain, silicon carbide, crystallized glasses, alumina and the like. Films of the present oxide solutions can be applied to the surface of such substrates utilizing art-recognized plasma deposition technology or by so-called metal organic decomposition techniques, such as those described in U.S. Pat. No. 3,658,568, issued Apr. 25, 1972 and U.S. Pat. No. 4,485,094, issued Nov. 27, 1984, the disclosures of which patents are expressly incorporated herein by reference. Generally lanthanum strontium chromites for use in accordance with this invention can be applied as thin films to refractory materials by first applying a solution of a mixture of soluble metal salts or metal complexes to the surface of said substrates followed by oxide-forming pyrolysis. The stoichiometry of the resulting solid oxide solution film corresponds to the stoichiometry of the metal organic components of the precursor solutions. It is anticipated that the refractory substrates for deposition of lanthanum strontium chromites for use in accordance with this invention can have similar structure/geometry to those substrates used heretofore for support of noble metal catalysts intended for use in similar applications.
In a preferred embodiment of this invention, lanthanum strontium chromites of the above defined stoichiometry can be used as an effective catalyst for treatment of automotive exhaust and allied pollution abatement processes. Thus the solid metal oxide solutions can be utilized as sintered pellets or as films or coatings on conventional refractory substrates in the same manner as noble metal catalysts are presented in the commercial catalytic converters now enjoying wide use in the automotive industry. The present lanthanum strontium chromites can be used as a cost effective alternative to art-recognized noble metal reforming catalysts and other hydrotreating catalytic agents.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Solid solutions of the general formula La 2-x Sr x CuO 4- ∂ and La 1-x Sr x CrO 3- ∂ were prepared by conventional ceramic techniques. The constituent metal oxides were quantitatively mixed in the desired stoichiometric ratio and pelletized. Each pellet was sintered in an alumina crucible in air for 12 hours at the appropriate temperature. The sintering temperature for the cuprates was 1050° C. to 1100° C., while the sintering temperature for the chromites was 900°-920° C. Cycles of grinding, pelletizing and heating were repeated three times on each sample to ensure complete reaction and solution homogeneity. X-ray diffraction, SEM and EDX showed that each sample was a homogeneous single phase. The component oxides used to prepare the solid solutions were high purity (99.99%) from Puratronic Specialty Products from AESAR (Johnson Mathey). In each instance the final pellets were ground and a sieve fraction between 10 μm and 35 μm was used for the catalytic studies. Surface area of the solid solutions was measured by the BET N 2 adsorption technique.
For the catalytic studies, 0.5% platinum on γ- alumina, supplied by Englehart Industries, Inc., was utilized as a control catalyst. Platinum site counting on the catalyst was accomplished utilizing carbon monoxide chemisorption as well as hydrogen-oxygen titration.
Temperature programmed catalytic studies were carried out in a multi-functional in situ catalyst characterization unit at the University of Notre Dame. The tests were made utilizing a fixed feed concentration of gas mixtures (1% CO in oxygen) through a fixed amount of powdered catalyst (0.25 g) to maintain constant contact time. The conversion of carbon monoxide was determined as a function of temperature while the catalyst was programmably heated at a rate of 2° C. per minute. The effluent from the gradientless recycling reactor was sampled using a zero volume sampling valve at different time intervals, and was analyzed by means of a gas liquid chromatograph interfaced with an automatic integrator.
TABLE 1______________________________________Activity of the oxidation catalysts for CO oxidation* Activity (Temperature for 50% CO conversion)Catalyst** La/(La + Sr) (°C.)______________________________________CuSrO.sub.2 0 227LaSrCuO.sub.4-∂ *** 0.5 212La.sub.1.6 Sr.sub.0.4 CuO.sub.4-∂ 0.8 192La.sub.1.8 Sr.sub.0.2 CuO.sub.4-∂ 0.9 202La.sub.1.9 Sr.sub.0.1 CuO.sub.4-∂ 0.95 201La.sub.2 CuO.sub.4-∂ 1.0 240CuO -- 146La.sub.2 O.sub.3 -- 192SrO -- 244ND1 (La.sub.0.8 Sr.sub.0.2 CrO.sub.3-∂) -- 122ND2 (La.sub.0.7 Sr.sub.0.3 CrO.sub.3-∂) -- 1390.5% Pt/Alumina -- 98______________________________________ *Flow rate 100 ml/min of a 1% CO in oxygen at normal temperature and pressure **Weight of the catalyst = 0.25 g. ***∂ is an index of deviation from stoichiometry.
The measured activity of the various metal oxide catalysts are reported in Table 1 as the temperature at which 50% conversion of carbon monoxide was reached for a constant amount of catalyst (0.25 g). Generally, solid solutions of La 2-x Sr x CuO 4- ∂ were determined to be less reactive than those of La 1-x Sr x CrO 3- ∂. Further, the solid solution exhibited a significant difference in catalytic activity from the tested component metal oxides and that generally the lanthanum strontium chromites were found to be more active than the corresponding cuprates for carbon monoxide oxidation. Indeed, the activity of the solid solutions of the general formula La 1-x Sr x CrO 3- ∂ was found to be comparable to that of platinum/alumina catalysts. Two of the lanthanum strontium chromites, ND1 (x=0.2) and ND2 (x =0.3) were synthesized and the catalytic kinetics of carbon monoxide oxidation on these compositions were evaluated. The results of that study are summarized in FIG. 1 which illustrates the light-off temperature curves of carbon monoxide oxidation for ND1(a); ND2(b); La 1 ·6 Sr 0 ·4 CuO 4- ∂ (c), and platinum/alumina catalyst(d) . The reported values were obtained for a 1% carbon monoxide concentration. The activity period of the lanthanum strontium chromites ND1 and ND2 is shown in FIG. 1 to be very similar to that of the platinum/alumina catalyst. Further, the kinetic studies of carbon monoxide oxidation on these solid solutions appear to follow the same Langmuir-Hinshelwood model as that of the platinum/alumina catalyst. It is noted that the upper limit of the light-off temperature curves for solid solution ND1 evidences a carbon monoxide conversion superior to that of the platinum catalyst.
Additional data were obtained for comparison of the specific activity of ND1 and ND2 relative to that of the platinum/alumina catalyst. The results of those additional studies are summarized in Table 2. In the case of the metal oxide catalysts, the BET area was used to calculate the specific activity, as it was not possible to find a suitable probe to count the active sites specifically.
It is noted that the BET area can be controlled by time and temperature of catalyst preparation. Higher BET areas can be realized by using lower catalyst preparation temperatures with longer heating periods. Elevated BET areas should reduce temperatures required for effective catalyst activity for both oxidation and hydrogenation reactions.
One problem suffered by many catalysts is their susceptibility to sulfur poisoning in oxidizing atmospheres. Testing performed on metal oxide solution catalysts ND1 has shown that its exposure to hydrogen sulfide at room temperature for 12 hours resulted in no loss of carbon monoxide oxidation activity.
The activity of the lanthanum strontium chromite ND1 (x=0.2) was also compared with platinum/alumina catalysts for propylene hydrogenation. FIG. 2 illustrates the results of that evaluation for a system in which the feed contained 3.8% propylene. The light-off temperature curve for ND1 [(a) in FIG. 2] indicates that metal oxide solid solution has a kinetic catalytic activity very similar to both fresh 0.5% Pt/Alumina (b) and a Pt/Alumina catalyst sintered at 600° C. (c).
TABLE 2__________________________________________________________________________Specific activity of the oxidation catalysts Wt. of the Specific.sup.+ catalyst BET Area Exposed area activityCatalyst (g) (m.sup.2 /g) (m.sup.2) (moles of CO/m.sup.2 h)__________________________________________________________________________Pt/Alumina 0.12 249 0.27@ 0.04 0.47* 0.02ND1 (La.sub.0.8 Sr.sub.0.2 CrO.sub.3-∂) 0.25 0.33 0.08** 0.02ND2 (La.sub.0.7 Sr.sub.0.3 CrO.sub.3-∂) 0.25 0.35 0.09** 0.02__________________________________________________________________________ .sup.+ Specific rate is moles of CO reacted per unit contact time per exposed area. As the difference in the temperature range for 50% conversion is very close, the conversion was compared at different temperatures, the error involved is very slight compared to the magnitude @Specific surface area of Pt measured by CO chemisorption technique *Specific surface area of Pt measured by hydrogenoxygen titration technique **BET Area X g | Solid oxide solutions of the formula La 1-x Sr x CrO 3- ∂ have been found to exhibit suprisingly high specific activity as catalysts for oxidation and hydrogenation reactions. The oxide solutions can be utilized in particulate form or applied as films to the surfaces of refractory substrates. The oxide solution catalysts are expected to be a viable alternative to the noble metal catalysts now used commercially for treatment of combustion chamber exhaust gases to reduce environmental pollutants. | 8 |
THE FIELD OF THE INVENTION
The present invention relates to an interconnected lock assembly of the type in which an inside handle, either knob or lever, simultaneously retracts both a deadlatch and a deadbolt. Such a lock assembly is commonly found in public accommodations such as hotels and motels in which, for security purposes, the occupant wishes to set both a deadlatch and a deadbolt. The same type of lock assembly may also be found in a residential environment. It is particularly important that both locks be retracted by the turning of a single inside operating member as it has been found that in the event of a fire or other panic situation it is desirable that the occupant only need turn a single knob or lever to operate all of the lock mechanisms in a particular door.
Such interconnected lock assemblies have been on the market for a number of years. The principal disadvantage of currently available products of this type is that there is a fixed distance relationship between the two latch assemblies with the result that door preparation can be difficult if there is a slight misalignment of the latch assembly bores. Further, it is difficult to retrofit an existing door if the distance between bore centerlines is not the same as the distance between the latch assemblies of the interconnected lock. The present invention addresses this problem by providing an interconnected lock assembly in which the distance between the two latch mechanisms comprising the lock assembly is variable and easily adjustable. The increments of adjustment are fine to accommodate slight variation caused by imperfect boring on the part of the installer. Also, the lock mechanism has the ability to provide a very substantial range of adjustment to accommodate a variety of pre-bored door applications.
SUMMARY OF THE INVENTION
The present invention relates to interconnected lock assemblies of the type in which one handle may retract two spaced locks in a single door, and has particular relation to such a lock assembly providing for adjustable spacing between the lock assemblies.
A primary purpose of the invention is to provide an interconnected lock assembly which is simple in construction, reliably operable and provides for a substantial range of adjustment between the spacing of the two lock mechanisms.
Another purpose is an interconnected lock assembly of the type described which provides for fine increments of adjustment to accommodate slight variation caused by imperfect boring in door installation.
Another purpose is to provide an adjustable interconnected lockset to accommodate differences in center-to-center distance between the upper and lower lock assemblies.
Another purpose is an interconnected lock assembly providing for adjustment between the spacing of the lock mechanisms which is easy to install and reliable in operation.
Other purposes will appear in the ensuing specification, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated diagrammatically in the following drawings wherein:
FIG. 1 is an exploded perspective illustrating the interconnected lock assembly of my invention;
FIG. 2 is an enlarged exploded perspective of the lower interconnected unit;
FIG. 3 is an enlarged exploded perspective of one side of the upper interconnected unit;
FIG. 4 is an enlarged exploded perspective of the opposite side of the upper interconnected unit;
FIG. 5 is a plan view of the interconnected unit in an inoperative position; and
FIG. 6 is a plan view of the interconnected unit in an operative position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The interconnected lock assembly of the present invention consists of certain basic elements. There is an inside knob 10 which, although shown as a knob may also be a lever, a decorative escutcheon 12, which masks the interconnecting assembly comprising the lower interconnected unit 14 and the upper interconnected unit 16. There is an upper unit latch 18 which in conventional practice will be a typical deadbolt latch. There is an outside upper unit 20 which may either function as a means for mounting the upper interconnected unit 16 or may itself include a standard locking unit such as a cylinder lock or it may be a locking arrangement which is operable by other means, for example, an electrically operated remote control. There is a lower unit latch 22 which may be a conventional deadlatch operated through a spindle 24 extending outwardly from an outside lock assembly 26 which may include a conventional cylinder lock. In normal operation, turning of the inside knob 10 will retract the lower deadlatch 22 and through the interconnecting assembly made up of lower unit 14 and upper unit 16, will also retract the deadbolt 18. The outside knob assembly 26 may similarly turn and retract or lock both the deadlatch and the deadbolt.
The inside knob 10 may have a thumb button assembly 28 extending through an opening thereof to set the lock mechanism. Rotation of knob 10 will turn an inside sleeve 30 which in turn will rotate an inside spring driver 32, a lower unit cam 34, an inside torsion spring 36 and a spindle driver 38. Sleeve 30 has a plurality of axially extending projections 40 separated by axial slots 42. Spring driver 32 has diametrically opposed inwardly directed projections 44 which are positioned in slots 42 to provide the driving connection between the sleeve and the inside spring driver. The spring driver in turn has two axially extending projections 46 which pass through aligned openings 48 in the lower unit cam. The projections 46 also interact with the ends 50 of torsion spring 36 to the end that when the sleeve, spring driver and lower unit cam are turned by knob 10, the torsion spring will return these elements to their original position when the knob is released.
The lower interconnected unit includes a frame 52 comprising a pair of spaced rails 54 and cross members 56. At the lower end of frame 52 there is a cylindrical boss 58 which is effective to mount torsion spring 36, cam 34, spring driver 32 and sleeve 30. The spindle driver 38 has four spaced openings 60 which will receive the axial projections 40 of inside sleeve 30 with the projections being staked to the spindle driver to form a completely factory assembled unit. The spindle driver has a central opening 62 which will receive the spindle 24 so that rotation of the spindle driver by knob 10 will turn the spindle as will rotation of the outside knob assembly 26.
The frame 52 has a slideway 64 within which is positioned a lower unit slide 66. The longitudinal interior edges of slide 66 have a plurality of uniform and closely spaced teeth 68 which will form the driving connection with the upper unit slide to be described.
The upper interconnected unit 16 includes a housing 70 which through the use of an upper unit mounting plate 72 will be fastened to the door. The outside upper unit 20 will receive the fastening members such as screws which will pass through the openings 74 in mounting plate 72 to thereby position and fasten the upper interconnected unit 16 to the door. Both the upper unit 16 and the lower unit 14 will be mounted on the inside of the door and will be covered by the escutcheon plate 12. The spacing between these units is determined by the spacing of the bores which mount the deadbolt 18 and the deadlatch 22. The upper unit housing 70, which will be mounted above the lower unit 14, interconnects with the lower unit through the upper unit slide 76.
Slide 76 has outer edges with a plurality of uniformly and closely spaced teeth 78 which will mesh with the teeth 68 on the lower unit slide 66. Because the teeth are small in dimension they provide for fine adjustment between the upper and lower unit spacing and thus fine adjustment to accommodate slight variance in spacing between the bores for the deadbolt 18 and the deadlatch 22. The distance spanned by the teeth on the upper and lower slides may, for example, provide for a range of adjustment of approximately 31/2 to 61/2 inches.
The slide 76 will be driven by the slide 66 which in turn will be driven by the cam 34. There are a pair of return springs 80 each of which are mounted on a ledge 82 on the upper unit slide 76 and are each positioned between the ledge and a shoulder 84 at the top of a spring opening 86 formed in the upper unit housing 70. Springs 80 normally urge both slides to the down position which is the position when both of the locks are operated. The slides move up to retract the locks and latches.
The upper unit housing 70 has a central opening 88 which mounts the cylindrical portion 90 of an upper unit pinion gear 92. The cylindrical portion 90 extends through opening 88 and through a similar opening 91 in the mounting plate 72 and the pinion is held in position by a snap ring 94. There is a hands-free spring clip 96 which also snaps into upper unit housing 70 in an opening 98. The spring clip will attach to the outside upper unit 20 to hold these elements together during mounting.
The upper unit pinion gear 92 has an opening 100 which mounts a tail piece 102 which in turn functions as the spindle for operating the deadbolt 18. Rotation of the pinion gear turns the tail piece which in turn retracts or locks the deadbolt. The exterior of the pinion gear 92 has a plurality of gear teeth 104 which mesh with similar size gear teeth 106 on upper unit multiplier gear 108. The multiplier gear rotates on a boss 110 formed on the upper unit housing 70 and will be driven by movement of the upper unit slide and particularly the inwardly directed arms 112 formed on the upper surface thereof. An assembly pin 114 extends through a central opening 116 in the upper unit slide 76 and fits within a central bore 118 in boss 110. The pin 114 provides guidance for slide movement and prevents disassembly of the upper unit slide from the upper unit housing.
As indicated above, the interconnecting mechanism may be operated by either the inside or the outside knob. When operated by the outside knob, the spindle 24 will turn the spindle driver which in turn will cause cam 34 and sleeve 30 to turn. When the unit is operated from the inside, rotation of knob 10 turns sleeve 30 turning the inside spring driver 32, cam 34, torsion spring 36 and the spindle driver 38.
In either instance, rotation of cam 34 causes one of its shoulders 120 to contact the underside of lower unit slide 66. This moves the slide in an upward direction causing slide 76 to move with it. As slide 76 moves in an upward direction, one of the in-turned arms 112 will cause rotation of the upper unit multiplier gear 108 about boss 110. As this gear rotates it turns pinion gear 92 with the result that tail piece 102 will turn causing retraction of the deadbolt. Thus, both the deadlatch and the deadbolt are operated by turning either the inside or the outside knob.
To assemble the interconnected lock assembly, after the bores for the deadbolt and deadlatch have been formed, these units are placed in position. Next, the upper interconnected unit 16 and the outside upper unit 20 are assembled to the door and secured with tie screws through the openings 74. The lower interconnected unit 14 and the outside knob chassis 26 are then installed. The upper unit may pivot to allow for imperfect alignment between the teeth of the two slides. The installer must make sure that the upper and lower slide teeth mesh properly for consistent and reliable operation. After alignment is completed the lower tie screws in the lower unit mounting plate are positioned and screwed home. The decorative cover or escutcheon is then snapped onto the unit and the inside knob or lever is slipped onto the sleeve 30.
Of importance in the invention is the ability to account for variant spacing between the bores for the deadbolt and the deadlatch. The use of a plurality of fine teeth on two interconnected slides provides not only the ability to accommodate variation in bore spacing but also provides the drive mechanism between the handle that turns the deadlatch and the mechanism that operates the deadbolt. The invention should not be limited to this particular configuration for providing for variant spacing between the deadbolt and deadlatch bores. Other constructions may be equally satisfactory. What is important is to provide for such adjustment and to provide a reliable drive between the mechanism which operates the deadlatch and the mechanism which operates the deadbolt.
Alternate means for adjusting the center to center distance between the upper and lower units include a worm screw which may be turned in the appropriate direction at installation to increase the distance between such units, the distance being maintained by the friction preventing undesirable rotation of the worm screw or through a secondary fastening means; a rack and pinion may be used in which at installation the pinion is turned which has the effect of moving one slide with respect to another, thus changing the effective center to center distance between the upper and lower units, the pinion may be spring loaded to maintain the slides in a locked position during operation of the locks; a set screw may be utilized to hold the upper and lower units in any adjusted position, with the screw being threaded through a tapped hole in the upper slide into a slot in the lower unit slide. The above are merely exemplary of possible alternate means to provide for adjustment of the upper and lower units to account for variant spacing between the bores in a door.
Whereas the preferred form of the invention has been shown and described herein, it should be realized that there are many modifications, alterations and substitutions thereto within the scope of the following claims. | An interconnected lock assembly for use on a door includes a first latch adapted to be positioned in a first bore in the door and a second latch adapted to be positioned in a second bore in the door, spaced from the first bore. There is an outside operating member operably connected to the first latch for causing operation thereof and there is an inside operating member operably connected to the first latch for also causing operation thereof. There is an interconnecting mechanism operably connected to the inside operating member and to the second latch. The interconnecting mechanism is effective to cause operation of the second latch when the first latch is operated by the inside operating member. The interconnecting mechanism is adjustable as to length to accommodate variant spacing between the first and second bores. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/911,852, filed Dec. 4, 2013, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Various blood pumps are known for pumping the blood of a patient to provide assistance to his/her ailing heart. Particularly, implantable, magnetically driven, rotary ventricular assist devices (VADs) are blood pumps which may, if desired, be implanted in the patient to provide assistance in pumping blood for hearts that are afflicted with congestive heart failure or the like.
[0003] Axial flow pumps for blood have the advantage of narrow width, as compared to radial flow pumps. Typically, an axial flow pump has a cylindrical housing with an inlet, an outlet, and a rotor within the housing having impeller blades attached to the rotor. A set of electrical coils is disposed around the housing to provide a rotating magnetic field which spins the rotor. As the rotor rotates, the impeller blades propel the fluid (e.g., blood) through the inlet of the pump and out of the outlet. Radial flow pumps, such as the HVAD® pump of HeartWare, Inc., the Applicant, also have applicability in pumping blood for patients afflicted with congestive heart failure or the like.
[0004] Known axial flow pumps for blood have typically been made of suitable biocompatible metals, such as titanium. Generally, the pump is not inherently sealed. Stated another way, pumps of the prior art typically include separate components that require sealing (e.g., through the use of O-rings or other sealing devices) to attempt to establish a sealed environment around the coils. An example of such a prior art pump is shown in FIGS. 5A-C . Joining of components is not always fully effective and is, in some cases, subject to failure. In addition, the multitude of components makes for a difficult and expensive assembly of the pump since there are multiple seal points to establish.
[0005] In particular reference to the pump 120 of FIGS. 5A-C , as can be seen the pump includes a variety of components that require assembly. For instance, as shown in FIG. 5C , the pump includes upper and lower volute portions 130 , 132 , a metal casing 134 , a tubular housing 136 , a stator 138 , and a rotor 140 . Various sealing rings 142 are also provided. In its assembled form as shown in FIGS. 5A-B , the various parts mentioned above must be pieced together and, in many cases, certain parts are adhered or connected together in some manner. For instance, stator 138 is adhered to tubular housing 136 and an epoxy backfill is used to secure stator 138 to metal casing 134 during assembly. Further, sealing rings 142 are utilized in an effort to create a sealed environment for pump 120 . Assembly of pump 120 therefore requires a number of pieces and occupies time and effort to ensure pump 120 operates in a sealed environment.
BRIEF SUMMARY OF THE INVENTION
[0006] A first aspect of the present invention includes a blood pump comprising a pump housing having a chamber with an inlet and an outlet, a rotor within the chamber of the pump housing, the rotor having an impeller for pumping blood through the blood pump, a motor including a plurality of magnetic poles carried by the rotor, and a stator including a plurality of electrically conductive coils adjacent to and at least partially surrounding the pump housing. The blood pump includes an over-molded monolithic enclosure covering the stator, the enclosure and the pump housing cooperatively sealingly enclosing the stator. In some embodiments, the enclosure directly contacts the pump housing at various contact points, thereby securing the pump housing relative to the enclosure. Also, the enclosure may be composed of a biocompatible polymer.
[0007] A second aspect of the present invention includes a method of manufacturing a blood pump comprising the steps of positioning a stator within a mold, the stator including a plurality of electrically conductive coils for interacting with a rotor, and molding an enclosure around the stator while in the mold so that the enclosure at least partially sealingly encloses the stator and borders a blood-flow lumen of the pump. As with above, the enclosure may be composed of a biocompatible polymer. In embodiments of this second aspect, the stator is sealed off from the flow of blood through the blood pump by molding the enclosure around the stator in the manner described. Thus, the stator can operate freely without contact from possibly harmful fluids that might damage the stator. In an embodiment, the step of molding the enclosure includes molding the enclosure around the stator so that the enclosure forms a unitary part with the stator.
[0008] A third aspect of the present invention includes a blood pump comprising a structure having a monolithic molded enclosure, the structure defining a blood-flow lumen having an inlet and an outlet, a rotor within the blood-flow lumen, the rotor having an impeller for pumping blood through the blood pump, a motor including a plurality of magnetic poles carried by the rotor, and a stator including a plurality of electrically conductive coils adjacent to and at least partially surrounding the blood-flow lumen, wherein the molded monolithic enclosure covers the stator, the enclosure at least partially sealingly enclosing the stator and encasing the blood-flow lumen. In an embodiment, the enclosure defines the blood-flow lumen. In another embodiment, however, the structure includes a pump housing formed separately from the enclosure, the blood-flow lumen being at least partially defined by the pump housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more complete appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description, in which reference is made to the accompanying drawings:
[0010] FIG. 1 is an exploded perspective view of a blood pump, according to an embodiment of the present invention;
[0011] FIG. 2 is a perspective view of a top part of the blood pump of FIG. 1 ;
[0012] FIGS. 3A-B are cross-sectional views of the top part of FIG. 2 ;
[0013] FIGS. 4A-B are cross-sectional views of the blood pump of FIG. 1 , fully assembled;
[0014] FIGS. 5A-C are cross-sectional and exploded views of a prior art blood pump of the type described above; and
[0015] FIGS. 6A-C are various exploded, perspective, and cross-sectional views of an existing HVAD® pump, while FIG. 6D is a chart detailing the components thereof.
DETAILED DESCRIPTION
[0016] In describing certain features of the present invention, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to any specific terms used herein.
[0017] FIG. 1 depicts a blood pump 18 according to an embodiment of the present invention. Blood pump 18 includes a pump housing 60 . Housing 60 is a generally tubular structure formed from a non-magnetic material as, for example, a ceramic. The housing 60 has an inner chamber 66 for carrying blood or other fluid through pump 18 , an inlet 62 for accepting the blood, and an outlet 64 for discharging the blood. A rotor 70 is positioned in pump housing 60 for pumping blood or other fluids through pump 18 . A stator 40 ( FIG. 4A ) incorporating a plurality of electrical coils (not shown) surrounds pump housing 60 . The coil arrangement itself may be conventional. For example, the stator may include three sets of coils. Each such set may include two coils disposed on opposite sides of the housing. The sets may be arrayed at equal spacings around the circumference of the housing. The coils are connected to an electrical cable 90 , commonly referred to as a driveline, incorporating electrical leads 90 A ( FIG. 4A ).
[0018] A monolithic enclosure 20 is, in one embodiment, formed from a biocompatible polymer that is over molded onto pump housing 60 and stator 40 to assist in creating a fully fluid-tight (in some cases hermetic) enclosure, which encompasses the exterior of pump housing 20 , the stator 40 , and the leads 90 A of driveline 90 . Blood pump 18 is therefore operable in a fluid-filled environment, such as the interior of a human or other mammalian body, to pump blood.
[0019] In one embodiment, upstream and downstream sections 24 , 26 of pump housing 60 are in direct contact with enclosure to establish a seal at sections 24 , 26 (e.g., a hermetic seal). For instance, enclosure 20 may be molded around pump housing 60 , as described in more detail below, so that enclosure directly contacts sections 24 , 26 of pump housing 60 to establish an immediate seal with pump housing 60 at sections 24 , 26 . Pump housing 60 also includes an inner chamber 66 for carrying blood or other fluid through pump 18 , an inlet 62 for accepting the blood, and an outlet 64 for discharging the blood. In addition, since enclosure 20 contacts pump housing 60 (e.g., at upstream and downstream sections 24 , 26 ), it is stabilized in the upstream-to-downstream direction relative to enclosure 20 .
[0020] As shown in FIGS. 3A-B and 4 A-B, enclosure 20 defines an inlet 22 . An upper lip 38 may be formed on enclosure 20 for overlying an upstream edge of pump housing 60 (e.g., the edge of its inlet 62 ) so that a seamless transition is provided between inlet 22 of enclosure 20 and inlet 62 of pump housing 60 . Likewise, a lower lip 39 may be formed on enclosure 20 for overlying a downstream edge of pump housing 60 (e.g., the edge of its outlet 64 ) so that a seamless transition is provided between outlet 64 of pump housing 60 and a downstream portion of enclosure 20 . In one embodiment, inlet 62 of pump housing 60 is also reduced in diameter as compared to its outlet 64 , as shown. Although enclosure 20 may be formed with upper and lower lips 38 , 39 providing seamless transitions, it is also contemplated that pump housing 60 may provide the sole inlet to pump 18 and enclosure 20 may, for example, be molded about a middle section of pump housing 60 . Thus, in this embodiment, the ends of pump housing 60 may protrude somewhat from the ends of enclosure 20 .
[0021] As shown in FIGS. 3A-4B , an annular cavity 28 is formed between pump housing 60 and enclosure 20 for housing stator 40 . Cavity 28 circumferentially surrounds pump housing 60 and receives stator 40 . In one embodiment, enclosure 20 is molded around pump housing 60 (e.g., injection molded) while stator 40 is positioned on housing 60 so that molded enclosure 20 contacts stator 40 and precisely forms cavity 28 to conform to the shape of stator 40 . In this manner, stator 40 is secured relative to enclosure 20 and pump housing 60 by virtue of over molding. Stated another way, when enclosure 20 is molded around pump housing 60 and stator 40 , it forms a unitary part with pump housing 60 and stator 40 and secures such components relative to each other. The enclosure also encompasses leads 90 A of drive line 90 . The enclosure defines a driveline conduit 30 projecting away from the housing. The driveline 90 extends out of the enclosure through conduit 30 . Desirably, conduit 30 is formed in the same molding operation used to form the remainder of enclosure 20 . Thus, the material of the enclosure bonds to the exterior of the driveline and forms a seal. Thus, without additional seals or other components, stator 40 and its cavity 28 are effectively sealed from chamber 66 of pump housing 60 and the flow of blood therethrough. A long-lasting fully-sealed environment is therefore established in which pump 18 can operate without the worry of leaking or failure of the sealed environment. Fewer components are also used to establish the sealed environment. As mentioned above, in one embodiment the environment is hermetic. In addition, enclosure 20 may be molded over pump housing 60 and stator 40 so that enclosure 20 contacts other points besides upstream and downstream sections 24 , 26 , and establishes a seal at those points.
[0022] In a particular embodiment, enclosure 20 is molded over stator 40 in such a way as to form a cavity 28 with surfaces 29 transverse to an upstream-to-downstream direction ( FIGS. 3A-B ). Surfaces 29 abut the ends of stator 40 , as shown in FIGS. 4A-B , so that stator 40 is secured in the upstream-to-downstream direction. In other words, surfaces 29 are separated by a distance that is approximately equal to or only insignificantly greater than a distance between the ends of stator 40 so that stator 40 is secured in the upstream-to-downstream direction. Because of this, stator 40 does not need to be secured to pump housing 60 , as is the case in certain prior art pumps. For example, certain prior art pumps include a pump housing that is adhered to the stator (e.g., through adhesion/cure techniques) to further secure it in position. This is the case with pump 120 of FIGS. 5A-C . With blood pump 18 , no such step is needed. Instead, stator 40 is secured in the upstream-to-downstream direction relative to pump housing 60 by way of molding enclosure 20 over stator 40 and housing 60 . Cavity 28 is likewise formed to facilitate securing stator 40 relative to pump housing 60 and to conform to the shape of stator 40 . Thus, stator 40 remains in position relative to pump housing 60 during operation so that rotor 70 can be appropriately positioned, and remain in position, in chamber 66 of pump housing 60 .
[0023] As shown in FIGS. 1 and 4 A-B, drive line wires 90 may be connected to stator 40 to control the operation thereof, either prior to or after the molding process for enclosure 20 . Wires 90 may be connected to terminals on stator 40 , for example three ( 3 ) terminals for three-phase operation of stator 40 , and wrapped around stator 40 exiting through cable conduit 30 of enclosure 20 . Wires 90 may also be wrapped about a section of pump housing 60 for strain relief purposes. Drive line 90 extends from stator 40 to a controller (not shown), which provides power for operating stator 40 and blood pump 18 . The controller may be outside of the patient's body, or may be an internal implantable controller. If an internal controller is used, it may be associated with a battery having inductive charging capabilities for charging the battery for pump 18 .
[0024] Referring now to FIGS. 1-2 , enclosure 20 is also molded so as to have an upper volute portion 36 defining part of an outlet of pump 18 . In particular, as shown in FIGS. 3A-B , upper volute portion 36 is unitary with the rest of enclosure 20 , it being a unitary molded part, and includes a disc-like chamber that is arranged to accept blood or other fluid from outlet 64 of pump housing 60 . Upper volute portion 36 also includes outlet portion 32 , which is roughly semi-tubular in shape.
[0025] One or more openings 34 is provided in enclosure 20 adjacent upper volute portion 36 so as to connect upper volute portion 36 with a lower volute portion 100 , as shown in FIGS. 1 and 4A . In particular, one or more rivets, screws, or other fixation mechanisms 110 are inserted through opening(s) 34 to secure upper volute portion 36 to a lower volute portion 100 and form a complete volute having an outlet. Referring to FIGS. 1 and 4 A-B, lower volute portion 100 includes an annular chamber 106 defined by a center post 104 (in some cases domed), and an outlet portion 102 for interacting with outlet portion 32 of upper volute portion 36 . Once lower volute portion 100 is connected to upper volute portion 32 via fixation mechanism(s) 110 , as shown in FIGS. 4A-B , a complete volute with an outlet for discharging blood is formed. Blood can therefore travel through pump 18 , in particular chamber 66 of pump housing 60 , and exit into the volute to be driven into circumferential flow by center post 104 and subsequently out of the outlet defined by outlet portions 32 , 102 . In other words, counter pressure generated by rotor 70 may cause blood or other fluid to interact with center post 104 and move circumferentially within the volute and out of its outlet.
[0026] Rotor 70 may be any suitable rotor for fitting within chamber 66 of pump housing 60 and driving blood through pump 18 . In one embodiment, rotor 70 includes an impeller defining various blades 74 used to impel blood through pump 18 . The blades may have spaces or channels 76 between them for channeling blood through rotor 70 . In addition, one or more hydrodynamic surfaces 72 may be included on rotor 70 for creating a frictionless operation within pump 18 . Stated another way, hydrodynamic surfaces 72 may be included with rotor 70 so that a layer of blood forms a barrier between rotor 70 and pump housing 60 and rotor 70 can rotate within pump housing 60 against the layer of blood in a frictionless or near-frictionless environment. Hydrodynamic surfaces 72 may also act to cause rotation of rotor 70 . Hydrodynamic surfaces of the type disclosed herein are described in detail in U.S. Pat. No. 8,007,254, assigned to the Applicant, HeartWare, Inc., the disclosure of which is incorporated by reference herein. Any of the rotors of the '254 patent may be utilized with blood pump 18 , if desired. Likewise, any of the disclosed stators of the '254 patent could be utilized with blood pump 18 as well.
[0027] Rotor 70 may be composed of a magnetic alloy, such as platinum cobalt, and may include a plurality of permanent drive magnets for interacting with stator 40 . Again, such drive magnets are described in the '254 patent. Rotor 70 is hydrodynamically and/or magnetically suspended in pump housing 60 by virtue of its interaction with stator 40 , and is operable to rotate within chamber 66 once stator 40 is activator to drive blood through pump 18 . As stator 40 is secured relative to pump housing 60 in the manner described above (e.g., through molding), rotor 70 is also stabilized within chamber 66 during operation. In other words, since stator 40 is secure in the upstream-to-downstream direction, the position of rotor 70 will not be affected by any unintended movement of stator 40 .
[0028] In use, blood pump 18 is implanted within a patient suffering from, for example, congestive heart failure to assist in pumping of blood from the heart. Blood pump 18 may be positioned to support either a left ventricle of the heart (LVAD) or a right ventricle (RVAD). In some cases, blood pump 18 is implanted into the pericardial space directly adjacent to the heart (e.g., with inlet 22 in either the right or left ventricle at the respective apex). The outlet defined by outlet portions 32 , 102 is positioned outside of the heart and is attached to a tubular conduit (not shown), referred to as a graft. Where the inlet is positioned in a ventricle, the graft is in turn connected to the aorta to establish blood flow through pump 18 and to the aorta. In some cases, a sewing ring is utilized to mount pump 18 on the heart, and an apical coring tool is used to establish access to the heart.
[0029] The molding process for pump 18 uses an appropriate biocompatible material, for instance a thermoplastic such as polyether ether ketone (PEEK), a PEEK composite, or any other suitable implantable grade polymer, optionally having one or more of the following properties: rigid, good electrical insulation properties, chemical resistance, and able to withstand sterilization processes (e.g., ETO). While the use of an injection-molding system is described below, it is recognized that any suitable molding system may be used (e.g., transfer molding), and that the description of injection molding herein is only exemplary. In a particular embodiment, after selecting the appropriate material, an injection mold (not shown) shaped to produce the desired exterior shape of enclosure 20 is provided. Pump housing 60 with a stator 40 surrounding it is then inserted into the mold. The mold may have a highly-polished surface finish so as to achieve a smooth exterior surface for pump 18 via the molding process. Proper equipment is used to stabilize pump housing 60 and stator 40 within mold so that such components are not mistakenly moved during the injection molding process. In one embodiment, drive line 90 is also connected to stator 40 while in the mold, and leads 90 A extend out of the mold by some distance so that the entirety of line 90 is not over molded (e.g., to allow for later connection to other components). An alternate embodiment allows for drive line 90 to be connected after the molding process.
[0030] A shot of the biocompatible material is then heated and forced under pressure into the mold where it surrounds pump housing 60 , stator 40 , and drive line 90 to form enclosure 20 . A unitary part is therefore established comprising pump housing 60 , stator 40 , and enclosure 20 . As described previously, during the molding process enclosure 20 directly contacts and bonds to upstream and downstream sections 24 , 26 of pump housing 60 , effectively establishing a seal (e.g., hermetic) at those sections 24 , 26 to seal off stator 40 (and its cavity 28 ) from the rest of pump 18 . The unitary part comprising pump housing 60 , stator 40 , and enclosure 20 can then be attached with the other components of pump 18 (e.g., lower volute 100 , rotor 70 , a controller, etc.) for implantation and use within the patient.
[0031] Although the foregoing embodiments are described as utilizing certain structures, others may also be employed and are equally contemplated within the scope of the invention. For example, although a separately-formed pump housing 60 is utilized with blood pump 18 , it is not a necessary component and may be omitted, in one embodiment. In this case, stator 40 may be positioned in a mold and a biocompatible material of the type discussed above (or another material) may be molded over stator so as to establish an enclosure 20 that has a continuous lumen through it from an inlet side 22 to an outlet. Thus, instead of supplying pump housing 60 and enclosure 20 to establish a blood-flow lumen, it is contemplated that enclosure itself may be molded over stator 40 in such a way to establish a blood-flow lumen without pump housing 60 . Stated another way, in this embodiment the material of the enclosure also forms the pump housing, and the pump housing is part of the same monolithic element as the enclosure. In certain embodiments, the flow lumen of such an enclosure 20 may also be surface treated or hardened to provide for improved characteristics in the flow-lumen area. Thus, in this embodiment, stator 40 is sealed from the blood-flow lumen (e.g., hermetically), but enclosure 20 itself defines the lumen via the molding process.
[0032] As another option, while rotor 70 is disclosed as being composed of platinum cobalt, it may alternatively be injection molded (or ceramic injection molded—CIM) out of a biocompatible material. In this instance, a series of permanent magnets may be molded into rotor 70 (e.g., on surfaces of the impeller blades) so that rotor 70 can interact properly with stator 40 and rotate to drive blood through blood pump 18 . In another example, the molded rotor may have a slot(s) in the blades to allow the insertion of a permanent magnet(s) after molding.
[0033] In a variant of the process discussed above, the enclosure may be formed from a thermosetting polymeric material such as an epoxy, which cures by chemical reaction in the mold.
[0034] In yet another variant, lower volute 100 may be composed of a metal material (e.g., titanium), any of the biocompatible polymer materials discussed above, or a combination thereof. Indeed, lower volute 100 (or a portion thereof, for instance its center post 104 ) is composed of titanium or another suitable metal in one embodiment to improve the durability of lower volute 100 (and/or the portion made of metal). In particular, center post 104 may be composed of titanium or another suitable metal to increase its durability while the reminder of lower volute 100 may be composed of any of the biocompatible polymer materials noted above. In such an embodiment, center post 104 may be insert molded with the remainder of polymer lower volute 100 . Alternatively, the entirety of lower volute 100 may be metal.
[0035] Further, while the above-described molding process is disclosed as being usable with an axial flow pump, it is equally usable with a radial flow pump having, for example, a centrifugal pump. Such a pump is offered by the Applicant, HeartWare, Inc., as its HVAD® pump. An existing HVAD® pump of the type described is shown in detail in FIGS. 6A-C , with the components thereof designated in the chart shown in FIG. 6D . In one embodiment, it is contemplated that parts 10, 12, 4, 7, 8, and 9 may be molded as a first unitary piece using any of the aforementioned molding processes, and that parts 2, 1, 4, 3, 5, and 6 may be molded as a second unitary/composite piece. Further, the first and second unitary pieces may then be joined together to form the HVAD® device. In addition, although not shown, a centrifugal impeller of the type used in the HVAD® pump may be fitted around center post 11 to pump blood within the cavity created by the first and second unitary pieces ( FIG. 6C ). The centrifugal impeller is operated by front and rear motors 12 , 3 . In these embodiments, the molding of the first and second unitary pieces can sealingly enclose front and rear motors 12 , 3 (e.g., without additional parts and/or seals) so that such are isolated from the flow of blood through the HVAD® pump. Other molded combinations beyond that discussed above are also contemplated, of course.
[0036] In yet another variant, a sensor may be embedded into a portion of enclosure 20 of pump 18 during the molding process. For instance, a sensor capable of taking diagnostic measurements concerning the operation of pump 18 and/or the patient may be embedded into enclosure 20 . In one embodiment, an accelerometer may be embedded in enclosure 20 for determining the positioning of pump 18 . The sensor may be connected to an electrical lead, fiber optic cable, or other suitable connection for conveying the information gleaned via the sensor to the pump 18 's controller, or to an external system. The sensor alternatively could have wireless capabilities for transmitting such information. Thus, the sensor could allow for ascertaining significant information concerning pump 18 's operation, its position, or the condition of the patient.
[0037] While the pump of this invention is also described in terms of a blood pump, it is contemplated that the pump might be used for pumping other fluids as well.
[0038] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
[0039] It will also be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims, and that the features described in connection with individual embodiments may be shared with others of the described embodiments. In particular, as understood by one of skill in the art, the features of any dependent claim may be shared with a separate independent or dependent claim, to the extent feasible. | Various blood pumps and methods of manufacture therefor are disclosed. An embodiment of a blood pump comprises a blood-flow lumen having an inlet and an outlet, and a rotor within the blood-flow lumen, the rotor having an impeller for pumping blood through the blood pump. A motor is also provided including a plurality of magnetic poles carried by the rotor, and a stator including a plurality of electrically conductive coils adjacent to and at least partially surrounding the blood-flow lumen. An over-molded monolithic enclosure covers the stator, the enclosure at least partially sealingly enclosing the stator and encasing the blood-flow lumen. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 13/604,363 filed Sep. 5, 2012, which is a divisional of U.S. application Ser. No. 12/614,224, filed Nov. 6, 2009.
[0002] This application is related to the following commonly-owned, co-pending United States patent application filed on even date herewith, the entire contents and disclosure of which is expressly incorporated by reference herein in its entirety: U.S. patent application Serial No. (24626), for “METALLURGICAL CLAMSHELL METHODS FOR MICRO LAND GRID ARRAY FABRICATION”.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT
[0003] This invention was made with Government support under Contract No.: HR0011-07-9-0002 awarded by (DARPA) Defense Advanced Research Projects Agency. The Government has certain rights in this invention.
BACKGROUND
[0004] The present invention relates generally to the electrical contact structures in the field of microelectronics, and more particularly, relates to electrical contact structures and a method for manufacturing the same for microelectronics and semiconductor manufacturing.
[0005] Typical Land Grid Array (LGA) interconnects are 2-dimensional arrays of compliant electrical contacts that are sandwiched between two electrical devices, and pressed together to establish electrical contact. The application of force using hardware which surrounds both electrical devices provides the pressing together of the electrical devices. Primarily, varieties of LGAs include: 1. the geometry and constituent materials of the individual contacts; 2. the method of fabrication. The method of fabrication typically includes: 2a. one-shot array formation, i.e., molded or sheet stamped; and 2b. sequential placement of individual contacts to form an array. Example of known LGA fabrication techniques are disclosed in U.S. Pat. Nos. 7,331,796. 7,137,827, and 7,452,212, all of which are commonly assigned with the instant application, and the subject matter of which are hereby incorporated by reference in their entirety.
[0006] However, decreasing the size of contact structures negatively affects mating of electrical contacts on each of the electrical devices being pressed together.
[0007] It would be desirable to provide an electrical contact structure and method for manufacturing the same which provides smaller scaling of the contact structure with increased contact between electrical contact structures.
BRIEF SUMMARY
[0008] In an aspect of the present invention, a contact structure for microelectronics includes first and second electrically conductive contacts having defined lengths, both the first and second contacts being helically shaped; and a carrier element attached to and positioned between the first and second contacts, the first and second contacts being in electrical communication with each other, and the first and second contacts being in a mirror image relationship with each other.
[0009] In a related aspect, the first contact is a right handed helix and the second contact is a left handed helix. In another related aspect, a pair of insulating substrates including electrically conductive members, and at least one contact point on each of the first and second contacts are attached to respective electrically conductive members. The first and second contacts may be symmetrical about a vertical axis bisecting the first and second contacts. The first and second contacts may be symmetrical about a horizontal axis bisecting the first and second contacts. A metal layer ma be on the carrier element providing electrical conductivity through a first opening defined by the carrier element between the first and second portions of the helix shaped contact. A second opening may be defined by the carrier element provides electrical conductivity through the second opening between the first and second portions of the helix shaped contact. In a further aspect, a pair of insulating substrates may include electrically conductive members, and at least one contact point on each of the first and second contacts are attached and electrically communicating to respective electrically conductive members such that the first and second electrically conductive contacts between the pair of insulating substrates form an electrically conductive package; and a metal layer on the carrier element provides electrical conductivity through a first opening defined by the carrier element between the first and second portions of the helix shaped contact; the first and second electrically conductive contacts between the pair of insulating substrates being in a compressed state relative to an at rest state; and a rotational displacement of the first and second contacts on the electrically conductive members between the compressed state and the at rest state.
[0010] In another aspect of the invention, a method for manufacturing a contact structure for microelectronics manufacturing comprises: providing a carrier element defining a first opening therethrough; positioning a molded element on opposite sides of the carrier element by passing the molded element partially through the first opening; coating the molded element with an electrically conductive material; fabricating a helix shaped contact from the electrically conductive material on the opposite sides of the carrier element, the helix shaped contact being positioned over the molded element, the helix shaped contact having a first portion and a second portion on the opposing sides of the carrier element, respectively, and the first and second portions being in mirror image relationship to each other; heating the combined helix shaped contact and the molded element such that the molded element is ablated and the helix shaped contact substantially retains the shape of the molded element.
[0011] In a related aspect, the helix shaped contact is a metal alloy; and the step of heating further includes: annealing the helix shaped contact; and quenching the helix shaped contact. The method may include the molded element as a molded sacrificial polymer element. The molded element may be cone shaped. The method may include: applying a plurality of conductive metal coatings to the conductive element. The step of fabricating the helix shaped contact may include using photolithography. A metal layer on the carrier element may provide electrical conductivity through the first opening between the first and second portions of the helix shaped contact. The method may include a second opening defined by the carrier element, and a metal layer on the carrier element providing electrical conductivity through the second opening between the first and second portions of the helix shaped contact. The method may include: positioning at least one contact point on each of the first and second contacts between a pair of insulating substrates including electrically conductive members; and positioning the at least one contact point on each of the first and second contacts to electrically communicate with respective electrically conductive members to form an electrically conductive package. The method may further comprise: compressing the first and second contacts between the insulating substrates such that the first and second contacts twist on the electrically conductive members during the compression.
[0012] In another aspect of the invention, a contact assembly for a microelectronics device, comprises: first and second electrically conductive contacts having defined lengths, both the first and second contacts being helically shaped; a carrier element attached to and positioned between the first and second contacts, the first and second contacts being in electrical communication with each other, and the first and second contacts being in a mirror image relationship with each other; a pair of insulating substrates each including electrically conductive members, and at least one contact point on each of the first and second contacts are attached and electrically communicating to respective electrically conductive members such that the first and second electrically conductive contacts between the pair of insulating substrates form an electrically conductive package; and a metal layer on the carrier element provides electrical conductivity through a first opening defined by the carrier element between the first and second portions of the helix shaped contact.
[0013] In a related aspect, a second opening defined by the carrier element provides electrical conductivity through the second opening between the first and second portions of the helix shaped contact. The assembly may further comprise: the first and second electrically conductive contacts between the pair of insulating substrates being in a compressed state relative to and at rest state; and a rotational displacement of the first and second contacts on the electrically conductive members between the compressed state and the at rest state.
[0014] In another aspect of the invention, a process for manufacturing a contact structure for microelectronics manufacturing, comprises: positioning a molded element having a specified geometric shape on a carrier element; sequentially coating the molded element with a plurality of electrically conductive materials; coating the molded element with a layer of photoresist; fabricating a contact from the electrically conductive materials on the carrier element using photolithography and etching, the contact being positioned over the molded element; and heating the contact and the molded element such that the molded element is ablated and the contact retains the shape of the molded element. The contact may be a helix shaped contact.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. The various features of the drawings are not to scale as the illustrations are for clarity in facilitating one skilled in the art in understanding the invention in conjunction with the detailed description. In the drawings:
[0016] FIG. 1 is flow chart of a method of the invention according to one embodiment of the invention;
[0017] FIGS. 2A-2I are diagrammatic view of process steps depicting the process for manufacturing a hollow LGA array according to an embodiment of the invention;
[0018] FIGS. 3A-3B are perspective views of helical contacts in reverse directions;
[0019] FIG. 3C is a side elevational view of a contact assembly having helical contact in mirror image relation separated by a carrier element;
[0020] FIG. 3D is a perspective view of the contact assembly in FIG. 3C ;
[0021] FIG. 4 is a perspective view of a plurality of helical contacts used in high frequency electrical simulation;
[0022] FIG. 5 is a perspective view of an illustrative metal and photo resist coated molded polymer bump sitting within a form fitting cavity;
[0023] FIG. 6 is a plan view of a mask pattern shaped as a four leg helix;
[0024] FIG. 7 is a isometric bottom view of the mask pattern shown in FIG. 6 ;
[0025] FIG. 8 is an isometric view of a single side of a molded sacrificial polymer element;
[0026] FIG. 9 is an isometric view of the element shown in FIG. 8 , having a metal helix spring contact formed over the element;
[0027] FIG. 10 is an isometric view of the spring contact of FIG. 9 after the sacrificial polymer element shown in FIGS. 8 and 9 has been ablated;
[0028] FIG. 11 is a plan view of a group of four mask pattern openings in a helix pattern;
[0029] FIG. 12 is a graph of a return loss in dB (reflected energy) for right hand-left hand (RH-LH) and right hand-right hand (RH-RH) spring contact types; and
[0030] FIG. 13 is a graph of effects of spring contact leg rotation on electrical transmissive loss performance.
DETAILED DESCRIPTION
[0031] Referring to FIG. 1 , a method 10 according to one embodiment of the present invention includes the general steps below including step 14 forming a substrate with a 2d array of vias (for example, conducting vias) as a first step to forming a 2d array of contacts. Two different alternatives can be pursued after step 14 , a first path is to manufacture contacts shaped from thermally decomposable polymers in step 40 . Contact elements are shaped from thermally decomposable polymers, and the sacrificial polymers are molded into a carrier plane with vias. The plurality of contact may be formed in an array of contacts having a pattern.
[0032] A second path is to mold elastomeric contact elements into a carrier plane in step 20 . After either steps 20 or 40 , the contact elements are metalized using known methods in step 44 . Both paths continue in step 48 wherein the protruding contact elements are coated with metal layers and photo resist. A conformally coating resist such as electrophoretically deposited photo resist is used to coat the protruding contacts.
[0033] A metal mask for positioning over both sides of the LGA protrusions includes cavities of complementary shape to the protrusions and is placed over an array of protrusions in step 52 . The cavities are of similar shape to a desired contacts, but slightly larger to account for the photo resist thickness and any tolerance. The masks have patterns in the top formed as slots by wire electric discharge machining (EDM), laser, and other techniques. The patterns transmit light into a pattern onto the photo resist covered contacts or LGA protrusions, without allowing for significant reflections from one contact to another because they are nestled into individual cavities. Then the metal mask is clamped together, e.g., top and bottom portions of the metal mask can be clamped together.
[0034] Referring to FIG. 2 , a process 100 for manufacturing hollow LGA array using a mold includes a perforated insulator 104 as shown in FIG. 2A . The perforated insulator 104 includes a large hole 106 and a small hole 108 . A polymer element 112 shown in FIG. 2B is oval shaped, however, other shapes may be used. A desired radius lip 620 shown in FIGS. 5 and 8 transitions from the polymer element to the substrate surface and is formed where the polymer contacts the substrate 408 in FIG. 5 . The polymer element 112 is molded into the perforation or hole 106 . A metal layer 120 is formed over the insulator 104 as shown in FIG. 2C , metalizing, for example, with copper (for example, 12.5 micrometers (um) thick). Another layer 124 is added over the metal layer 120 . The layer 124 , for example, can be beryllium about 2.5 microns thick. Another metal layer 128 , for instance a copper layer of about 12.5 um, is formed over the Be layer 124 in FIG. 2E . Onto this metal stack is deposited a photo resist 132 shown in FIG. 2F . The photoresist may be a conformal coating obtainable with electrophoretic resist. The metal stack with photo resist is referred to as a sample 136 , and is inserted between a form fitting top layer mask 140 and a form fitting bottom layer mask 142 as shown in FIG. 2G . Machined fine slots shown as curved and straight thin lines 148 in the body of masks 140 and 142 of FIG. 2G are cut into the masks 140 , 142 to define the pattern of light that will be able to penetrate to the metal stack with photo resist. A helical pattern is projected onto the metal stack with photo resist, and a linear strip is patterned leading to a via to the right of the polymer bump 112 which will act as an electrical conduit through the hole 108 to connect the final product of contact structure embodied as top and bottom helical springs 160 shown in FIG. 2I . After the sample 136 has been removed from the mask 140 , 142 , the resist 132 developed, and the exposed metal etched away the pre-finished part 150 includes metal remaining only where it is desired for manufacturing the final part. The pre-finished part 150 includes the polymer bump 112 , and the metal coating remaining in discrete layers 120 , 124 , 128 . Fabricating the 3D masks 140 , 142 utilized in process step 2 G may use fine wire EDM, laser cutting, plasma cutting, water jet cutting, all in combination with any standard machining that may also be required.
[0035] Referring to FIG. 2I , a high temperature bake out and anneal is performed in inert or chemically reducing gas environment during which the polymer 112 is decomposed and the metal layers 120 , 124 , 128 diffuse into one another forming a single metal alloy layer 164 . Upon cooling or quenching at a speed chosen to give the desired metallurgical microstructure (which varies from a sudden liquid nitrogen quench 10 deg.C/second, to a slow cool of 1 deg.C/day) the final contact structure 170 is formed as shown in FIG. 31 . The contact structure 170 includes the original insulator 104 and the double sided spring contact 160 which is electrically connected through the central plane by the single metal allow layer 164 via the small hole 108 .
[0036] Referring to FIGS. 3A and 3B , two LGA helical spring contacts are shown. A right handed helical contact 204 extending in the clockwise direction is shown in FIG. 3A . A left handed helical contact 208 extending in the counter clockwise direction is shown in FIG. 3B . Referring to FIGS. 3C and 3D , a contact assembly 212 includes a right handed helical contact 204 in mirror image relation with a left handed helical contact 208 having a carrier element 216 therebetween. The mirror image relation of the right handed and left handed helical contacts 204 , 208 , respectively, or helix reversal, imparts to a signal performance enhancements of the contacts at high frequencies.
[0037] Referring to FIG. 4 , a plurality of helical contact assemblies 212 (as shown in FIG. 3 C,) including right hand and left hand wind directions as described regarding FIG. 3C , are used in a package 300 . The package 300 includes the contact assemblies 212 between upper and lower substrates 304 , 308 , respectively. The package 300 provides helical contact assemblies 212 for a high frequency electrical applications.
[0038] Referring to FIG. 5 , an illustrative mask and polymer bump combination 400 includes a metal and photo resist coated molded polymer bump having a top portion 404 and a bottom portion 406 separated by a substrate 408 . The bump sits within a form fitting cavity 412 of a top portion of a mask solid 410 . The mask solid 410 includes a pattern 416 open to the outside. This example shows a slot pattern 416 , however, other patterns including multileg helix patterns can be used. A bottom portion of the mask (not shown) typically is clamped together with the top portion 410 . The closed mask solid is rotated and illuminated to provide light access through the slot pattern 416 , producing the desired image on the bump 404 , 406 .
[0039] Referring to FIGS. 6 and 7 , a mask 500 , is cut out of metal, and the pattern is cut out from the mask 500 as a four legged 504 helix pattern 502 . The helix pattern 502 allows light to pass through the cut away portions as shown in FIG. 6 . The helix pattern 502 includes the four legs 502 having circular pads 508 .
[0040] Referring to FIG. 8 , a single side of a molded sacrificial polymer element 600 is frustoconically shaped. The element, as used in the embodiments of the invention depicted herein, are two sided, i.e., having two elements 600 in opposing relation such that the element 600 is joined through a perforation in a center carrier.
[0041] Referring to FIG. 9 , an intermediate fabrication step includes molded polymer element 600 under a lithographically formed metal helix spring contact 610 . The helix spring contact 610 comprises different layers of metal (not shown) that will ultimately form an alloy after heat treatment and quenching in later processing.
[0042] Referring to FIG. 10 , the spring contact 610 shown in FIG. 9 is shown after a fabrication heating step wherein the sacrificial polymer element has been ablated (burned out or vaporized or other wise decomposed) and metal layers have been annealed to form alloy, and then the contact 610 is quenched to achieve the final metallurgy. Also shown is a conducting metal baseplate 620 which may be used in some instances to form mechanical anchoring of the helix legs and to electrically connect top and bottom sides of the contact 610 . The baseplate 620 may be use instead of, or in addition to, a conductive element connecting the contact through a separate via as shown in FIG. 2 .
[0043] Referring to FIG. 11 , a metal mask 650 includes a plurality of metal helix spring contacts 502 in a pattern on the metal mask 650 . In an alternative embodiment, a large plurality of contact 502 may be patterned on a metal mask, for example, hundreds or thousands of contacts to form a desired array of contacts
[0044] Referring to FIG. 12 , a graph 700 of return loss in dB (reflected energy) for right handed-right handed (RH-RH) 704 and right handed-left handed (RH-LH) 708 spring contacts is shown. The graph 700 shows much lower reflective losses for RH-LH spring contacts even at relatively low frequencies. Referring to FIG. 13 , a graph 750 of effects of spring contact leg rotation on electrical transmissive insertion loss performance is shown. RH-RH 758 is shown to have a more severe insertion loss than RH-LH 754 . This becomes especially pronounced above frequency of 5 GHz.
[0045] More specifically, the electrical performance of the helical contacts are illustrated in terms of their scattering parameters up to 20 GHz with ports defined at the top and the bottom of the contact. The reflection (referred as return) shown in FIG. 12 of the RH-LH type of contact is smaller than the RH-RH type, meaning less energy gets reflected when the signal propagates vertically through the contact. On the other hand, the transmission (referred as insertion), shown in FIG. 13 , of the RH-LH type of contact is larger than the RH-RH type, indicating more energy gets transmitted through the contact. Both graphs/plots 700 , 750 consistently demonstrate that the RH-LH type of contact has superior electrical performance to the RH-RH type in terms of signal integrity for high-speed signals.
[0046] Thereby the present invention provides helical spring positioned in mirror image relation to each other. For example, a contact structure comprised of two helical springs that are mirror images of each other across the plane defined by a central carrier. Further, referring to FIGS. 2A-2I , the present invention provides a process including the steps of: molding polymer template of LGA contacts into the top and bottom of an insulating carrier plane; metalizing over the polymer; coating with photo resist, preferably electrophoretic or other type of conformal coating method; sandwiching the metalized molded polymer LGA within a carrier between top and bottom 3D masks; photoexposing; removing LGA from mask, and completing the lithography; and heat treating the sample to burn away (cleanly vaporize) polymer template leaving hollow contact and complete the alloying of constituent metals.
[0047] In another embodiment of the invention similar to the process shown in FIGS. 2A-2I , however, the process uses elastomeric molded contacts instead of polymers meant to decompose, and eliminates the high temperature burn out step.
[0048] The present invention achieves a rotational or twisting effect of the helical contacts. This rotation upon compression is desirable to achieve scrubbing through oxide and other thin contaminant layers normally present on electronic contacts. A feature of these helical electrical contact structures is that the direction of helicity reverses as it passes through the central carrier plane, i.e. that the top and bottom helix structures are mirror images with respect to the carrier plane. This preserves the signal integrity of a computer signal at high frequencies by causing significant cancellation of electromagnetic induction.
[0049] The advantage of having a rotational scrubbing over typical lateral scrubbing is that as xy dimensions of LGA arrays are decreased, traditional lateral scrubbing increases the chance of the contact moving off the mating contact pad and resulting in an open circuit. Rotational scrubbing of an axiosymmetric contact does not move the contact relative to the position of the mating surface pad, and thus reduces the chances of a contact moving off a mating contact pad.
[0050] Additionally, metalization over a polymer, may include the methods for metalizing including electroplating, electro less plating, physical vapor deposition such as meal evaporation or sputtering, chemical vapor deposition, plasma spray, powder coating, etc. The metalizing could be a single layer or multiple layers of different metals.
[0051] In addition, coating with a photo resist, may include electrophoretic or other type of conformal coating method. The extreme z-dimension of LGA contacts complicates photolithography processes in several ways. In order to apply photo resist uniformly, one alternative is to use electrophoretic type photo resists. Electrophoretic resist may be used to provide uniform coverage of photo resist. Other methods of photo resist coating include spraying, spinning and liquid dipping.
[0052] 3D Masks are used to expose all coated surface with a uniform dose of light using the photo resist coated LGA pre-contacts inserted into form fitting cavities on the underside of a mask. The desired contact pattern is then cut into the top of the mask using a very fine resolution machining technique called wire EDM (electro discharge machining). The LGA precontact protrusions on both sides of a carrier plane are accordingly inserted into masks in a sandwich form. Thus, the part can be illuminated and photo lithographically defined from both sides. 3D masks include a plate of metal where the bottom has machined cavities that are form fitting to the metalized and photo resist coated LGA contact arrays. In practical application the cavities need to be a little bigger in dimension than the coated LGA contacts to account for any fabrication tolerances etc.
[0053] The final desired contact pattern is imparted to the mask by cutting or etching light pathways, or slots by wire EDM (wire electrodeposition machining) using very fine cutting wires. Alternatively, slots can be made by laser cutting, chemical etching, plasma etching etc. This slotting is expected to be most practically exercised cutting at right angle to the plane of the mask, i.e., through the z-direction of the mask metal. However, it can be advantageous to cut in a direction at right angles (normal) to the surface of the contact at any given location along the contact. Such normal-to-surface (NTS) slotting allow superior lithographic resolution and superior illumination uniformity. This process may be combined with chemical etching to achieve slot cuts of desired geometry.
[0054] During photoexposure the entire part and mask sandwich assembly is tilted and rotated to affect as uniform a photoexposure as possible. This is most easily accomplished by moving the assembly with rotation and tilt stages programmed to move through a path optimal for a given contact pattern. Alternatively, the light source can be made to move around the part. Alternatively, the light source can be shaped by holographic and other types of lenses to provide a uniform distribution of light from many directions at once. Once the lithography is completed, the LGA can be removed from the mask sandwich, and lithography steps of developing resist and etching metal into desired pattern are completed.
[0055] To obtain hollow contacts by cleanly burning or vaporizing away the polymer protrusions, e.g., the sacrificial polymer, heat is used, and also causes diffusion of multi layers of deposited metal into one another so they form alloys. Other methods of removing the temporary polymer bump, such as by chemical dissolving may be use.
[0056] In an alternative embodiment of the present invention, metal on elastomer contacts are formed using steps of 2 A- 2 E shown in FIG. 2 on molded elastomeric protrusions (bumps) rather than those made with sacrificial polymer. In this case, the metal will be left on the elastomer bump and used as part of the final contact.
[0057] In an alternative embodiment, a process includes depositing constituent metal layers over the sacrificial polymer protrusions. For instance, to make a thin film copper beryllium contact the contact may consist of variable Cu to Be ratios depending on the final properties desired. Alternatively, for example, electroplating 12.50 μm copper, then sputter deposit 2.5 μm of Beryllium, followed by the deposition of a second layer of 12.5 μm copper. This metal deposition would be followed by coating with photo resist (e.g. electrophoretic photo resist) and would be sandwiched into 3D egg carton like mask and exposed to light (e.g. Ultraviolet). The part would then be removed from the mask, the photo resist developed to remove protection from any metal desired to be removed. The unprotected areas of the metal would then be etched away. The part is then heated in an oven at sufficiently high temperatures and long enough period of time for the metals to diffuse together to form the alloy of interest after cooling at appropriate rates to obtain the temper of interest by controlled quenching. In this example, Cu and Be would need temperatures of 850 degrees C. for about an hour to diffuse (see Table 1 below). In the heating process the sacrificial polymer protrusions would have burned away and the remaining photo resist will have burned away (or could be removed chemically after the etching).
[0058] Table 1 shows the calculated time for a three-layer thin film (12.5 micron Cu/2.5 micron Be/12.5 micron Cu) to completely diffuse into one another. This informs us that if these three materials were sequentially deposited onto the sacrificial polymer, that heating to 850 deg. C would be required to achieve diffusion within one hour in a furnace, and that a temperature of 1000 deg. C would be required to shorten the time to 6 minutes. Once homogeneously dispersed, the attainment of desired mechanical properties requires controlled cooling to facilitate desired precipitation and achieve desired metallurgical microstructure.
[0000]
TABLE 1
Temp C.
time (h)*
400
1040042.8
425
296942.0
450
92456.9
475
31122.9
500
11241.0
525
4327.6
550
1765.5
575
759.4
600
342.8
625
161.7
650
79.5
675
40.6
700
21.4
750
6.6
800
2.2
850
0.8
900
0.3
950
0.2
1000
0.1
[0059] Further, alloys other than BeCu can be made using the above technique, such as Ni into Copper, which would take 3.3 hours at 1000 C. Other varieties of metal combinations of two or more constituent metals could be achieved in this way in the desired contoured shape.
[0060] The methods according to the present invention are applicable to any combination of metals including bi-metal alloys, ternary alloys, as well as any number of metals together to create an alloy. Other metals may be present, incidentally, for example, from adding adhesions layers, such as titanium and chromium.
[0061] While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated herein, but falls within the scope of the appended claims. | A contact structure and assembly for a microelectronics device includes first and second electrically conductive contacts being helically shaped. A carrier element is attached to and positioned between the first and second contacts. The first and second contacts are in electrical communication with each other, and the first and second contacts are in a mirror image relationship with each other. A pair of insulating substrates each include electrically conductive members. A contact point on each of the first and second contacts is attached and electrically communicating to respective electrically conductive members such that the first and second electrically conductive contacts between the pair of insulating substrates form an electrically conductive package. A metal layer on the carrier element provides electrical conductivity through a first opening defined by the carrier element between the first and second portions of the helix shaped contact. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No. 10/292,887 filed Nov. 12, 2002, now allowed, which claims benefit of priority from U.S. provisional application No. 60/336,781 filed Nov. 12, 2001.
FIELD OF THE INVENTION
The present invention relates to novel benzamide, heteroarylamide and reverse amide, processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them, and their use in therapy. The active compounds of the present invention are useful in the treatment of inflammatory diseases such as osteoarthritis and rheumatoid arthritis; allergies, asthma, COPD, cancer, reperfusion or ischemia in stroke or heart attack, autoimmune diseases and other disorders. The active compounds are also antagonists of the P2X 7 receptor.
The P2X 7 receptor (previously known as P2Z receptor), which is ligand-gated ion channel, is present on a variety of cell types, largely those known to be involved in the inflammatory/immune process, specifically, macrophages, mast cells and lymphocytes (T and B). Activation of the P2X 7 receptor by extracellular nucleotides, in particular adenosine triphosphate, leads to the release of interleukin-1β (IL-1β) and giant cell formation (macrophages/microglial cells), degranulation (mast cells) and proliferation (T cells), apoptosis and L-selectin shedding (lymphocytes). P2X 7 receptors are also located on antigen-presenting cells (APC), keratinocytes, salivary acinar cells (parotid cells), hepatocytes and mesangial cells.
P2X 7 antagonists are known in the art, such as International Patent Publications WO 01/46200, WO 01/42194, WO 01/44213, WO 99/29660, WO 00/61569, WO 99/29661, WO 99/29686, WO 00/71529, and WO 01/44170.
Benzamides, heteroarylamides and reverse amides for uses other than inhibition of P2X 7 have been published, such as International Patent Publications WO 97/22600, EP 138,527, WO 00/71509, WO 98/28269, WO 99/17777 and WO 01 58883.
SUMMARY OF THE INVENTION
The present invention relates to a compound of the formula
wherein A is —(C═O)NH— or —NH(C═O)—;
X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═(CR 8 )—; or ═N—, ═(CR 7 )—, and ═(CR 8 )—; or ═(CR 6 )—, ═N—, and ═(CR 8 )—; or ═(CR 6 )—, ═(CR 7 )—, and ═N—; or ═N—, ═(CR 7 )—, and ═N—; or ═(CR 6 )—, ═N—, and ═N—; or ═N—, ═N— and ═(CR 8 )—; respectively;
R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl containing one to six heteroatoms independently selected from —N═, —N<, —NH—, —O— and —S(O) n —; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl is substituted by at least one oxo group or one of said heteroatoms is —S(O) n —, wherein n is one or two; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any carbon atom able to support additional substituents, by one R 9 (preferably 1–8 R 9 groups per ring, more preferably 1–3 R 9 groups per ring), each R 9 is independently selected from the group of suitable substituents, such as hydrogen, halo, hydroxy, —CN, HO—(C 1 –C 4 )alkyl, (C 1 –C 4 )alkyl optionally substituted with one to three fluoro, (C 1 –C 4 )alkoxy optionally substituted with one to three fluoro, HO 2 C—, (C 1 –C 6 )alkyl-O—(C═O)—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(C═O)—, R 4 R 5 N(CH 2 ) t —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any ring nitrogen atom able to support an additional substituent by one to two R 10 groups per ring, each R 10 is independently selected from the group of suitable substituents such as hydrogen, (C 1 –C 4 )alkyl optionally substituted with one to three fluoro, (C 1 –C 4 )alkyl-(C═O)—, (C 1 –C 4 )alkyl-SO 2 —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 9 and R 10 substituents may optionally be substituted on any ring carbon atom by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
n is an integer from zero to two;
q is an integer one or two;
s is an integer from one to three;
t is an integer from zero to three;
R 2 is chloro, bromo, (C 1 –C 4 )alkyl, —CF 3 or —CN;
R 3 is selected from the group consisting of (C 4 –C 10 )alkyl, (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —, (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s —; wherein said (C 4 –C 10 )alkyl may optionally be independently substituted with one to three suitable substituents such as halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of said R 3 group members (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — contain one to three heteroatoms independently selected from —O— and —S(O) n —; wherein each of said R 3 group members (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —, (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—, (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — may optionally be substituted on any carbon atom able to support an additional independent suitable substituent, by one to four substituents per ring, such as halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, benzyl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said R 3 group members (C 3 –C 8 )cycloalkyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — may also optionally be substituted by oxo; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 3 substituents may optionally be substituted on any ring carbon atom by one to three independent suitable moieties per ring, such as halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle;
R 6 , R 7 and R 8 are each independently selected from the group consisting of hydrogen, halogen, cyano, hydroxyl, (C 1 –C 6 )alkyl optionally substituted by one to four chloro or fluoro, and (C 1 –C 6 )alkyloxy optionally substituted by one to four chloro or fluoro;
R 11 and R 12 are each independently selected from the group consisting of hydrogen, fluoro, cyano, hydroxyl, —CF 3 , CF 3 O—, (C 1 –C 6 )alkyl, (C 3 –C 8 )cycloalkyl, (C 1 –C 6 )alkyloxy, (C 3 –C 8 )cycloalkyloxy, phenyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein said (C 1 –C 6 )alkyl, (C 3 –C 8 )cycloalkyl, (C 1 –C 6 )alkyloxy, (C 3 –C 8 )cycloalkyloxy, phenyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl may optionally be substituted by one to three suitable substituents such as independently selected from chloro, fluoro, cyano, hydroxyl, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, or (C 1 –C 4 )alkyl-(C═O)—,
with the proviso that when said R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) 5 —; R 1 and R 2 are each hydrogen; and s is one or two; then said (C 3 –C 12 )cycloalkyl must be other than optionally substituted adamantyl;
or the pharmaceutically acceptable salts or solvates or prodrugs thereof.
The present invention also relates to the pharmaceutically acceptable acid addition salts of compounds of the formula I. The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as the chloride, bromide, iodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, acetate, lactate, citrate, acid citrate, tartrate, bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate [i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)]salts.
The invention also relates to base addition salts of formula I. The chemical bases that may be used as reagents to prepare pharmaceutically acceptable base salts of those compounds of formula I that are acidic in nature are those that form non-toxic base salts with such compounds. Such non-toxic base salts include, but are not limited to those derived from such pharmacologically acceptable cations such as alkali metal cations (e.g., potassium and sodium) and alkaline earth metal cations (e.g., calcium and magnesium), ammonium or water-soluble amine addition salts such as N-methylglucamine-(meglumine), and the lower alkanolammonium and other base salts of pharmaceutically acceptable organic amines.
This invention also encompasses pharmaceutical compositions containing prodrugs of compounds of the formula I. Compounds of formula I having free amino, amido, hydroxy or carboxylic groups can be converted into prodrugs. Prodrugs include compounds wherein an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues which are covalently joined through peptide bonds to free amino, hydroxy or carboxylic acid groups of compounds of formula I. The amino acid residues include the 20 naturally occurring amino acids commonly designated by three letter symbols and also include, 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline, homocysteine, homoserine, ornithine and methionine sulfone. Prodrugs also include compounds wherein carbonates, carbamates, amides and alkyl esters which are covalently bonded to the above substituents of formula I through the carbonyl carbon prodrug sidechain.
This invention also encompasses compounds of formula I containing protective groups. One skilled in the art will also appreciate that compounds of the invention can also be prepared with certain protecting groups that are useful for purification or storage and can be removed before administration to a patient. The protection and deprotection of functional groups is described in “Protective Groups in Organic Chemistry”, edited by J. W. F. McOmie, Plenum Press (1973) and “Protective Groups in Organic Synthesis”, 2nd edition, T. W. Greene and P. G. M. Wuts, Wiley-Interscience (1991).
The compounds of this invention include all stereoisomers (e.g., cis and trans isomers) and all optical isomers of compounds of the formula I (e.g., R and S enantiomers), as well as racemic, diastereomeric and other mixtures of such isomers.
The compounds, salts and prodrugs of the present invention can exist in several tautomeric forms, including the enol and imine form, and the keto and enamine form and geometric isomers and mixtures thereof. All such tautomeric forms are included within the scope of the present invention. Tautomers exist as mixtures of a tautomeric set in solution. In solid form, usually one tautomer predominates. Even though one tautomer may be described, the present invention includes all tautomers of the present compounds. One example of a tautomeric structure is when R 1 is a group of the formula
One skilled in the art will appreciate that this group can also be drawn as its tautomer
The present invention also includes atropisomers of the present invention. Atropisomers refer to compounds of formula I that can be separated into rotationally restricted isomers.
The compounds of this invention may contain olefin-like double bonds. When such bonds are present, the compounds of the invention exist as cis and trans configurations and as mixtures thereof.
A “suitable substituent” is intended to mean a chemically and pharmaceutically acceptable functional group i.e., a moiety that does not negate the inhibitory activity of the inventive compounds. Such suitable substituents may be routinely selected by those skilled in the art. Illustrative examples of suitable substituents include, but are not limited to halo groups, perfluoroalkyl groups, perfluoroalkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, hydroxy groups, oxo groups, mercapto groups, alkylthio groups, alkoxy groups, aryl or heteroaryl groups, aryloxy or heteroaryloxy groups, aralkyl or heteroaralkyl groups, aralkoxy or heteroaralkoxy groups, HO—(C═O)— groups, amino groups, alkyl- and dialkylamino groups, carbamoyl groups, alkylcarbonyl groups, alkoxycarbonyl groups, alkylaminocarbonyl groups dialkylamino carbonyl groups, arylcarbonyl groups, aryloxycarbonyl groups, alkylsulfonyl groups, arylsulfonyl groups and the like. Those skilled in the art will appreciate that many substituents can be substituted by additional substituents.
As used herein, the term “spiro” refers to a connection between two groups, substituents etc., wherein the connection can be depicted according to the following formula
As used herein, the term “alkyl,” as well as the alkyl moieties of other groups referred to herein (e.g., alkoxy), may be linear or branched (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, secondary-butyl, tertiary-butyl); optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. The phrase “each of said alkyl” as used herein refers to any of the preceding alkyl moieties within a group such alkoxy, alkenyl or alkylamino. Preferred alkyls include (C 1 –C 4 )alkyl, most preferably methyl and ethyl.
As used herein, the term “cycloalkyl” refers to a mono, bicyclic or tricyclic carbocyclic ring (e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclopentenyl, cyclohexenyl, bicyclo[2.2.1]heptanyl, bicyclo[3.2.1]octanyl and bicyclo[5.2.0]nonanyl, etc.); optionally containing 1 or 2 double bonds and optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “halogen” includes fluoro, chloro, bromo or iodo or fluoride, chloride, bromide or iodide.
As used herein, the term “halo-substituted alkyl” refers to an alkyl radical as described above substituted with one or more halogens included, but not limited to, chloromethyl, dichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trichloroethyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “alkenyl” means straight or branched chain unsaturated radicals of 2 to 6 carbon atoms, including, but not limited to ethenyl, 1-propenyl, 2-propenyl (allyl), iso-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “(C 2 –C 6 )alkynyl” is used herein to mean straight or branched hydrocarbon chain radicals having one triple bond including, but not limited to, ethynyl, propynyl, butynyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “carbonyl” or “(C═O)” (as used in phrases such as alkylcarbonyl, alkyl-(C═O)— or alkoxycarbonyl) refers to the joinder of the >C═O moiety to a second moiety such as an alkyl or amino group (i.e., an amido group). Alkoxycarbonylamino (i.e. alkoxy(C═O)—NH—) refers to an alkyl carbamate group. The carbonyl group is also equivalently defined herein as (C═O). Alkylcarbonylamino refers to groups such as acetamide.
As used herein, the term “oxo” is used herein to mean a double bonded oxygen (═O) radical wherein the bond partner is a carbon atom. Such a radical can also be thought as a carbonyl group.
As used herein, the term “(C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—” is used herein to mean a radical of the formula
As used herein, the term “aryl” means aromatic radicals such as phenyl, naphthyl, tetrahydronaphthyl, indanyl and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “heteroaryl” refers to an aromatic heterocyclic group usually with one heteroatom selected from O, S and N in the ring. In addition to said heteroatom, the aromatic group may optionally have up to four N atoms in the ring. For example, heteroaryl group includes pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, imidazolyl, pyrrolyl, oxazolyl (e.g., 1,3-oxazolyl, 1,2-oxazolyl), thiazolyl (e.g., 1,2-thiazolyl, 1,3-thiazolyl), pyrazolyl, tetrazolyl, triazolyl (e.g., 1,2,3-triazolyl, 1,2,4-triazolyl), oxadiazolyl (e.g., 1,2,3-oxadiazolyl), thiadiazolyl (e.g., 1,3,4-thiadiazolyl), quinolyl, isoquinolyl, benzothienyl, benzofuryl, indolyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. Particularly preferred heteroaryl groups include oxazolyl, imidazolyl, pyridyl, thienyl, furyl, thiazolyl and pyrazolyl. Most preferred R 3 heteroaryls are thienyl and furyl.
The term “heterocyclic” as used herein refers to a cyclic group containing 1–9 carbon atoms and 1 to 4 hetero atoms selected from N, O, S(O) n or NR′. Examples of such rings include azetidinyl, tetrahydrofuranyl, imidazolidinyl, pyrrolidinyl, piperidinyl, piperazinyl, oxazolidinyl, thiazolidinyl, pyrazolidinyl, thiomorpholinyl, tetrahydrothiazinyl, tetrahydrothiadiazinyl, morpholinyl, oxetanyl, tetrahydrodiazinyl, oxazinyl, oxathiazinyl, indolinyl, isoindolinyl, quinuclidinyl, chromanyl, isochromanyl, benzoxazinyl, and the like. Examples of said monocyclic saturated or partially saturated ring systems are tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, imidazolidin-1-yl, imidazolidin-2-yl, imidazolidin-4-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, piperidin-1-yl, piperidin-2-yl, piperidin-3-yl, piperazin-1-yl, piperazin-2-yl, piperazin-3-yl, 1,3-oxazolidin-3-yl, isothiazolidine, 1,3-thiazolidin-3-yl, 1,2-pyrazolidin-2-yl, 1,3-pyrazolidin-1-yl, thiomorpholin-yl, 1,2-tetrahydrothiazin-2-yl, 1,3-tetrahydrothiazin-3-yl, tetrahydrothiadiazin-yl, morpholin-yl, 1,2-tetrahydrodiazin-2-yl, 1,3-tetrahydrodiazin-1-yl, 1,4-oxazin-2-yl, 1,2,5-oxathiazin-4-yl and the like; optionally containing 1 or 2 double bonds and optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. Preferred heterocyclics include tetrahydrofuranyl, pyrrolidinyl, piperidinyl, piperazinyl and morpholinyl. A group of R 1 heterocycles of particular interest are those heterocycles with 2 or more oxo substituents. Another group of R 1 heterocycles of particular interest are those heterocycles with three or more heteroatoms. Another group of R 1 heterocycles include 2-oxazepinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxopyridyl and 2-oxoquinolinyl. Preferred R 1 heterocycles include 6-azauracil, uracil, 2-oxo-piperidine, 2,3-dioxo-piperazine, 2-oxo-oxazole and 2-oxo-benzthiazine, most preferably 6-azauracil. Preferred R 3 heterocyclics include tetrahydrofuranyl, dioxanyl, tetrahydrothiophenyl, chromanyl, isochromanyl and sulfolanyl.
Nitrogen heteroatoms as used herein refers to N═, >N and —NH; wherein —N═ refers to a nitrogen double bond; >N refers to a nitrogen containing two bond connections and —N refers to a nitrogen containing one bond.
“Embodiment” as used herein refers to specific groupings of compounds or uses into discrete subgenera. Such subgenera may be cognizable according to one particular substituent such as a specific R 1 or R 3 group. Other subgenera are cognizable according to combinations of various substituents, such as all compounds wherein R 2 is chloro and R 3 is optionally substituted phenethyl. The phrase “in combination with each of the aforementioned embodiments” refers to combinations of the identified embodiment with each embodiment previously identified in the specification. Thus an embodiment of compounds wherein R 3 is optionally substituted phenethyl “in combination with each of the aforementioned embodiments” refers to additional embodiments comprising combinations of the R 3 is optionally substituted phenethyl embodiment with each embodiment previously identified in the specification.
A preferred embodiment of the invention is that group of phenyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═(CR 8 )— respectively, more preferably wherein each of R 6 , R 7 , and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═N—, ═(CR 7 )—, and ═(CR 8 )— respectively, more preferably wherein each of R 7 and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═N—, and ═(CR 8 )— respectively, more preferably wherein each of R 6 and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═N— respectively, more preferably wherein each of R 6 and R 7 is hydrogen.
Another embodiment of the invention is that group of pyridazine compounds of formula I wherein X, Y and Z are ═N—, ═(CR 7 )—, and ═N— respectively, more preferably wherein R 7 is hydrogen.
Another embodiment of the invention is that group of pyrimidine compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═N—, and ═N— respectively, more preferably wherein R 6 is hydrogen.
Another embodiment of the invention is that group of pyrazine compounds of formula I wherein X, Y and Z are ═N—, ═N—, and ═(CR 8 )— respectively, more preferably wherein R 8 is hydrogen.
Another more preferred embodiment of the invention is that group of amide compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds) wherein A is —(C═O)NH— and are known as the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups, respectively.
Another embodiment of the invention is that group of reverse amide compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds) wherein A is —NH(C═O)— and are known as the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups, respectively.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 4 –C 10 )alkyl, more preferably substituted with one to three substituents independently selected from hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl or wherein at least one of R 11 and R 12 is other than hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); more preferably wherein said substituents include one to three substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said substituents are independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted by at least one substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted by at least one spiro substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl spiro substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —;
wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen);
wherein said (C 3 –C 12 )cycloalkyl of said (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — is substituted by one substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—; and
wherein said (C 3 –C 12 )cycloalkyl of said (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — is substituted by one or two substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said substituents are independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); more preferably wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by one to three substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, formyl, benzyloxy and (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by one to three substituents independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, benzyloxy and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); and wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by at least one substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); and wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by at least one spiro substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid spiro substituent may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on any ring carbon atom able to support an additional substituent by one to three substituents per ring independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)— (more preferably wherein said substituents are independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, formyl, and (C 1 –C 4 )alkyl-(C═O)—).
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on at least one ring carbon atom able to support an additional substituent by a substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O— substituent may optionally be substituted on any ring carbon atom by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on any ring carbon atom (more preferably one carbon atom) able to support an additional substituent by one to three substituents per ring independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—(more preferably wherein said substituents are independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, formyl, and (C 1 –C 4 )alkyl-(C═O)—).
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on at least one ring carbon atom (more preferably one carbon atom) able to support an additional substituent by a substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O— substituent may optionally be substituted on any ring carbon atom by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds wherein R 2 is chloro or bromo, more preferably wherein R 2 is chloro.
Another embodiment of the invention is that group of compounds wherein R 2 is (C 1 –C 4 )alkyl or —CN, more preferably wherein R 2 is methyl.
Another embodiment of the invention is that group of compounds wherein R 2 is hydroxy.
Another embodiment of the invention is that group of compounds wherein R 7 is other than hydrogen.
Another embodiment of the invention is that group of compounds of formula I wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
for simplicity, in the aforementioned examples of R 1 the substituents R 9 and R 10 have not been shown.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
for simplicity, in the aforementioned examples of R 1 the substituents R 9 and R 10 have not been shown.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 9 is selected from the group consisting of hydrogen, —CF 3 , (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group;
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group.
Another embodiment of the invention is that group of compounds wherein R 9 is independently selected from the group of substituents selected from hydrogen, halo, —CN, and (C 1 –C 4 )alkyl optionally substituted with one to three fluoro; more preferably hydrogen or methyl.
Another embodiment of the invention is that group of compounds wherein R 9 is independently selected from the group of substituents selected from hydroxy, amino, (C 1 –C 4 )alkoxy optionally substituted with one to three fluoro, HO 2 C—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(O═C)—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N— and R 4 R 5 N(CH 2 ) t —.
Another embodiment of the invention is that group of compounds wherein each R 9 is independently selected from the group of substituents selected from (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—.
Another embodiment of the invention is that group of compounds wherein R 10 is independently selected from the group of substituents consisting of hydrogen and (C 1 –C 4 )alkyl optionally substituted with one to three fluoro; more preferably hydrogen or methyl.
Another embodiment of the invention is that group of compounds wherein each R 10 is independently selected from the group of substituents consisting of (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, wherein each of the aforesaid (C 6 –C 10 )aryl and (C 3 –C 8 )cycloalkyl, anywhere on said R 10 substituents may optionally be substituted by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
Another embodiment of the invention is that group of compounds wherein each R 10 is independently selected from the group of substituents consisting of (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 10 substituents may optionally be substituted by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 —CH 2 —, CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another preferred embodiment of the invention is that group of compounds wherein R 1 is selected from the group
wherein R 9 is selected from the group consisting of hydrogen, —CF 3 , (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl or (C 3 –C 8 )cycloalkyl group.
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, CF 3 —CH 2 —, HO—(C 2 –C 6 )alkyl or (C 3 –C 8 )cycloalkyl group.
A preferred embodiment of the invention relates to compounds of formula I wherein R 1 is
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group.
A more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is (C 4 –C 10 )alkyl; wherein said (C 4 –C 10 )alkyl may optionally be substituted by one to four substituents independently selected from chloro, fluoro, (C 6 –C 10 )aryl, (C 3 –C 6 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of said (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl or (C 1 –C 10 )heterocyclyl may optionally be substituted on any carbon atom able to support an additional moiety, by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said (C 3 –C 8 )cycloalkyl and (C 1 –C 10 )heterocyclyl substituents may also optionally be substituted by oxo; and
R 10 is hydrogen or (C 1 –C 4 )alkyl;
or a pharmaceutically acceptable salt or solvate thereof.
Another more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein said (C 6 –C 10 )aryl may optionally be substituted by one to two substituents independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
or a pharmaceutically acceptable salt or solvate thereof.
Another more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl or wherein at least one of R 11 and R 12 is other than hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 ) heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—.
Examples of specific preferred compounds of the formula I are the following:
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2,2-diphenyl-ethyl)-benzamide; N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-benzamide; N-[2-(2-Benzyloxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-benzamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-benzamide; and 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide. Examples of other compounds of the formula I are the following: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-butyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(4-phenyl-butyl)-benzamide; 2-Chloro-N-[2-(4-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-phenethyl-benzamide; N-[2-(4-Bromo-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-fluoro-phenyl)-ethyl]-benzamide; 2-Chloro-N-[2-(2,6-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-methoxy-phenyl)-ethyl]-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-pentyl-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-ethoxy-phenyl)-ethyl]-benzamide; N-[2-(5-Bromo-2-methoxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-octyl-benzamide; 2-Chloro-N-[2-(3-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-N-[2-(2,4-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-hexyl-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(4-fluoro-phenyl)-ethyl]-benzamide; 2-Chloro-N-cyclohexylmethyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-N-[2-(3,4-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-phenyl-propyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-thiophen-2-yl-ethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-methoxy-phenyl)-ethyl]-benzamide; N-[2-(2-Bromo-4-methoxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-N-[2-(4-chloro-phenyl)-propyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cyclohexylmethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(5-hydroxy-1,3,3-trimethyl-cyclohexylmethyl)-benzamide; N-Bicyclo[2.2.1]hept-2-ylmethyl-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 3-{[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoylamino]-methyl}-cyclohexanecarboxylic acid methyl ester; N-Bicyclo[2.2.1]hept-2-ylmethyl-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-m-tolyl-ethyl)-benzamide; 2-Chloro-N-[2-(3-chloro-phenyl)-2-hydroxy-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-fluoro-phenyl)-2-hydroxy-ethyl]-benzamide; 3-{2-[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoylamino]-ethyl}-benzoic acid methyl ester; 2-Chloro-N-(6,6-dimethyl-bicyclo[3.1.1]hept-2-ylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-hydroxy-2-phenyl-ethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-isochroman-1-ylmethyl-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-methylsulfanyl-phenyl)-ethyl]-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-methoxy-2-phenyl-ethyl)-benzamide; 2-Chloro-N-(6,6-dimethyl-bicyclo[3.1.1]hept-2-ylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclopentylmethyl)-benzamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-methoxy-2-oxo-2H-pyridin-1-yl)-benzamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-ethyl-2,3-dioxo-piperazin-1-y)-benzamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-oxazolidin-3-yl)-benzamide; 2-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-benzamide; 2-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide; N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-methyl-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide; N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-methyl-5-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-benzamide; 5-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-2-methyl-benzamide; N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-methyl-benzamide; N-[2-Chloro-5-(3-methyl-2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-phenyl]-3-(2-chloro-phenyl)-butyramide; N-[2-Chloro-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-phenyl]-3-(2-chloro-phenyl)-3-methyl-butyramide; 2-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-benzamide; 2-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide; N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-2-methyl-5-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide; 2-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-5-(3-oxo-2,3-dihydro-[1,4]thiazin-4-yl)-benzamide; 2-Chloro-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-benzamide; 2-Chloro-5-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-4-yl)-N-(1-hydroxy-cycloheptylmethyl)-benzamide; 2-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-benzamide; 2-Chloro-N-(1-hydroxy-cycloheptylmethyl)-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide; 2-Chloro-N-cycloheptylmethyl-5-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide; 2-Chloro-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-benzamide; 2-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide; 2-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-benzamide; N-[2-Chloro-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-phenyl]-3-[2-(1-hydroxy-1-methyl-ethyl)-phenyl]-propionamide; and N-[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-phenyl]-3-[2-(1-hydroxy-1-methyl-ethyl)-phenyl]-propionamide.
Examples of specific nicotinamides of the invention include:
2-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-nicotinamide; 2-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide; N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-methyl-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide; N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-methyl-5-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-nicotinamide; 5-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-2-methyl-nicotinamide; N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-methyl-nicotinamide; 2-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-nicotinamide; 2-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide; N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-2-methyl-5-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide; 2-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-5-(3-oxo-2,3-dihydro-[1,4]thiazin-4-yl)-nicotinamide; 2-Chloro-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-4-yl)-N-(1-hydroxy-cycloheptylmethyl)-nicotinamide; 2-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-nicotinamide; 2-Chloro-N-(1-hydroxy-cycloheptylmethyl)-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide; 2-Chloro-N-cycloheptylmethyl-5-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide; 2-Chloro-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-nicotinamide; 2-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide; 2-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-nicotinamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2,2-diphenyl-ethyl)-nicotinamide; N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-nicotinamide; N-[2-(2-Benzyloxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-nicotinamide; 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide; 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-nicotinamide; and 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide.
Examples of specific isonicotinamides of the invention include:
5-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-2-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-isonicotinamide; 5-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide; N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-methyl-2-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide; N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-methyl-2-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-isonicotinamide; 2-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-5-methyl-isonicotinamide; N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-5-methyl-isonicotinamide; 5-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-isonicotinamide; 5-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide; N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-5-methyl-2-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide; 5-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-2-(3-oxo-2,3-dihydro-[1,4]thiazin-4-yl)-isonicotinamide; 5-Chloro-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-4-yl)-N-(1-hydroxy-cycloheptylmethyl)-isonicotinamide; 5-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-isonicotinamide; 5-Chloro-N-(1-hydroxy-cycloheptylmethyl)-2-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide; 5-Chloro-N-cycloheptylmethyl-2-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide; 5-Chloro-2-(3-methyl-5-oxo-1 ,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-isonicotinamide; 5-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide; 5-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-2-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-isonicotinamide; 5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2,2-diphenyl-ethyl)-isonicotinamide; N-[2-(2-Chloro-phenyl)-ethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-5-methyl-isonicotinamide; N-[2-(2-Benzyloxy-phenyl)-ethyl]-5-chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-isonicotinamide; 5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide; 5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-isonicotinamide; and 5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide.
Specific examples of other pyridine-2-carboxamides include:
3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide 3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (2,2-diphenyl-ethyl)-amide; 6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-3-methyl-pyridine-2-carboxylic acid [2-(2-Chloro-phenyl)-ethyl]-amide; 3-chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-Benzyloxy-phenyl)-ethyl]-amide; 3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (1-phenyl-cyclohexylmethyl)-amide; 3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (1-p-tolyl-cyclohexylmethyl)-amide; 3-Chloro-6-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide; 3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-trifluoromethyl-phenyl)-ethyl]-amide; and 3-Chloro-6-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide.
The present invention also includes isotopically-labelled compounds, which are identical to those recited in Formula I, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine, such as 2 H, 3 H, 13 C, 14 C, 15 N, 18 O, 17 O, 31 P, 32 P, 35 S, 18 F, and 36 Cl, respectively. Compounds of the present invention, prodrugs thereof, and pharmaceutically acceptable salts of said compounds or of said prodrugs which contain the aforementioned isotopes and/or other isotopes of other atoms are within the scope of this invention. Certain isotopically-labelled compounds of the present invention, for example those into which radioactive isotopes such as 3 H and 14 C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e., 3 H, and carbon-14, i.e., 14 C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium, i.e., 2 H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically-labelled compounds of Formula I of this invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the Schemes and/or in the Examples and Preparations below, by substituting a readily available isotopically-labelled reagent for a non-isotopically-labelled reagent.
The compounds of Formula I or a pharmaceutically acceptable salt thereof can be used in the manufacture of a medicament for the prophylactic or therapeutic treatment of any disease state in a human, or other mammal, which is exacerbated or caused by excessive or unregulated cytokine production by such mammal's cells, such as but not limited to monocytes and/or macrophages.
The present invention relates to a method for treating a P2X 7 mediated disease in a mammal in need thereof, which comprises administering to said mammal an effective amount of a compound of formula I.
The present invention also relates to a method for treating a condition selected from the group consisting of arthritis (including psoriatic arthritis, Reiter's syndrome, rheumatoid arthritis, gout, traumatic arthritis, rubella arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and acute synovitis), inflammatory bowel disease, Crohn's disease, emphysema, acute respiratory distress syndrome, adult respiratory distress syndrome, asthma, bronchitis chronic obstructive pulmonary disease, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoidosis, allergic reactions, allergic contact hypersensitivity, eczema, contact dermatitis, psoriasis, sunburn, cancer, tissue ulceration, restenosis, periodontal disease, epidermolysis bullosa, osteoporosis, bone resorption disease, loosening of artificial joint implants, atherosclerosis, aortic aneurysm, congestive heart failure, myocardial infarction, stroke, cerebral ischemia, head trauma, neurotrauma, spinal cord injury, neuro-degenerative disorders, Alzheimer's disease, Parkinson's disease, migraine, depression, peripheral neuropathy, pain, cerebral amyloid angiopathy, nootropic or cognition enhancement, amyotrophic lateral sclerosis, multiple sclerosis, ocular angiogenesis, corneal injury, macular degeneration, corneal scarring, scleritis, abnormal wound healing, burns, autoimmune disorders, Huntington's disease, diabetes, AIDS, cachexia, sepsis, septic shock, endotoxic shock, conjunctivitis shock, gram negative sepsis, toxic shock syndrome, cerebral malaria, cardiac and renal reperfusion injury, thrombosis, glomerularonephritis, graft vs. host reaction, allograft rejection, organ transplant toxicity, ulcerative colitis, or muscle degeneration, in a mammal, including a human, comprising administering to said mammal an amount of a compound to formula I, effective in treating such a condition.
The present invention relates to a pharmaceutical composition for the treatment of a P2X 7 mediated disease in a mammal which comprises an effective amount of a compound according to formula I and a pharmaceutically acceptable carrier.
The present invention relates to a pharmaceutical composition for the treatment of a condition selected from the group consisting of arthritis (including psoriatic arthritis, Reiter's syndrome, rheumatoid arthritis, gout, traumatic arthritis, rubella arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and acute synovitis), inflammatory bowel disease, Crohn's disease, emphysema, acute respiratory distress syndrome, adult respiratory distress syndrome, asthma, bronchitis, chronic obstructive pulmonary disease, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoidosis, allergic reactions, allergic contact hypersensitivity, eczema, contact dermatitis, psoriasis, sunburn, cancer, tissue ulceration, restenosis, periodontal disease, epidermolysis bullosa, osteoporosis, bone resorption disease, loosening of artificial joint implants, atherosclerosis, aortic aneurysm, congestive heart failure, myocardial infarction, stroke, cerebral ischemia, head trauma, neurotrauma, spinal cord injury, neuro-degenerative disorders, Alzheimer's disease, Parkinson's disease, migraine, depression, peripheral neuropathy, pain, cerebral amyloid angiopathy, nootropic or cognition enhancement, amyotrophic lateral sclerosis, multiple sclerosis, ocular angiogenesis, corneal injury, macular degeneration, corneal scarring, scleritis, abnormal wound healing, burns, autoimmune disorders, Huntington's disease, diabetes, AIDS, cachexia, sepsis, septic shock, endotoxic shock, conjunctivitis shock, gram negative sepsis, toxic shock syndrome, cerebral malaria, cardiac and renal reperfusion injury, thrombosis, glomerularonephritis, graft vs. host reaction, allograft rejection, organ transplant toxicity, ulcerative colitis, or muscle degeneration in a mammal, including a human, comprising an amount of a compound to formula I, effective in treating such a condition and a pharmaceutically acceptable carrier.
Preferably, the compounds of the invention are useful for the treatment of rheumatoid arthritis, osteoarthritis, psoriasis, allergic dermatitis, asthma, chronic obstructive pulmonary disease (COPD), hyperresponsiveness of the airway, septic shock, glomerulonephritis, irritable bowel disease, Crohn's disease, ulcerative colitis, atherosclerosis, growth and metastases of malignant cells, myoblastic leukemia, diabetes, Alzheimer's disease, meningitis, osteoporosis, burn injury, ischemic heart disease, stroke and varicose veins.
The present invention also provides a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined in the manufacture of a medicament for use in therapy.
The invention further provides a method of treating osteoarthritis which comprises administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The invention further provides a method of effecting immunosuppression (e.g. in the treatment of rheumatoid arthritis, irritable bowel disease, atherosclerosis or psoriasis) which comprises administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The invention also provides a method of treating an obstructive airways disease (e.g. asthma or COPD) which comprises administering to a patient a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The term “treating”, as used herein, refers to reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition. The term “treatment”, as used herein, refers to the act of treating, as “treating” is defined immediately above.
The present invention also provides a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined in association with a pharmaceutically acceptable adjuvant, diluent or carrier.
The invention further provides a process for the preparation of a pharmaceutical composition of the invention which comprises mixing a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined with a pharmaceutically acceptable adjuvant, diluent or carrier.
For the above-mentioned therapeutic uses the dosage administered will, of course, vary with the compound employed, the mode of administration, the treatment desired and the disorder indicated. The daily dosage of the compound of formula (I)/salt/solvate (active ingredient) may be in the range from 1 mg to 1 gram, preferably 1 mg to 250 mg, more preferably 10 mg to 100 mg.
The present invention also encompasses sustained release compositions.
The present invention also relates to processes of preparing the compounds of formula I and intermediates used in such processes.
One embodiment of the processes of the invention relates to the preparation of compounds of formula
wherein A, X, Y, Z, R 1 , R 2 and R 3 are as described above (including all embodiments and preferences of formula I described above); comprising reacting:
a) a compound of formula
wherein X, Y, Z, R 1 and R 2 are as defined above; L is halo or anhydro, with a compound of the formula
H 2 N—R 3 III
wherein R 3 is as defined above; and a base; or
b) a compound of the formula
wherein X, Y, Z, R 1 and R 2 are as described above; with a compound of formula
H 2 N—R 3 III
wherein R 3 is as defined above; in the presence of a coupling reagent, a base and a solvent; or
c) a compound of the formula
wherein X, Y, Z, R 1 and R 2 are as defined above; with a compound of the formula
wherein L 1 is a leaving group selected from the group consisting of chloro, fluoro, bromo, iodo or anhydro, and a base and a solvent.
Another embodiment of the present invention are intermediates of the formula
wherein X, Y, Z, R 1 , R 2 and L are described as above (including all embodiments and preferences for X, Y, Z, R 1 and R 2 described above).
Another embodiment of the present invention are intermediates of the formula
wherein X, Y, Z, R 1 and R 2 are as described above (including all embodiments and preferences for X, Y, Z, R 1 and R 2 described above).
One of ordinary skill in the art will appreciate that the compounds of the invention are useful in treating a diverse array of diseases. One of ordinary skill in the art will also appreciate that when using the compounds of the invention in the treatment of a specific disease that the compounds of the invention may be combined with various existing therapeutic agents used for that disease.
For the treatment of rheumatoid arthritis, the compounds of the invention may be combined with agents such as TNF-α inhibitors such as anti-TNF monoclonal antibodies (such as Remicade, CDP-870 and D 2 E 7 ) and TNF receptor immunoglobulin molecules (such as Enbrel®), COX-2 inhibitors (such as meloxicam, celecoxib, rofecoxib, valdecoxib and etoricoxib) low dose methotrexate, lefunomide; ciclesonide; hydroxychloroquine, d-penicillamine, auranofin or parenteral or oral gold.
The present invention still further relates to the combination of a compound of the invention together with a leukotriene biosynthesis inhibitor, 5-lipoxygenase (5-LO) inhibitor or 5-lipoxygenase activating protein (FLAP) antagonist selected from the group consisting of zileuton; ABT-761; fenleuton; tepoxalin; Abbott-79175; Abbott-85761; N-(5-substituted)-thiophene-2-alkylsulfonamides; 2,6-di-tert-butylphenol hydrazones; methoxytetrahydropyrans such as Zeneca ZD-2138; the compound SB-210661; pyridinyl-substituted 2-cyanonaphthalene compounds such as L-739,010; 2-cyanoquinoline compounds such as L-746,530; indole and quinoline compounds such as MK-591, MK-886, and BAY x 1005.
The present invention still further relates to the combination of a compound of the invention together with a receptor antagonists for leukotrienes LTB 4 , LTC 4 , LTD 4 , and LTE 4 selected from the group consisting of the phenothiazin-3-ones such as L-651,392; amidino compounds such as CGS-25019c; benzoxalamines such as ontazolast; benzenecarboximidamides such as BIIL 284/260; and compounds such as zafirlukast, ablukast, montelukast, pranlukast, verlukast (MK-679), RG-12525, Ro-245913, iralukast (CGP 45715A), and BAY x 7195.
The present invention still further relates to the combination of a compound of the invention together with a PDE4 inhibitor including inhibitors of the isoform PDE4D.
The present invention still further relates to the combination of a compound of the invention together with a antihistaminic H 1 receptor antagonists including cetirizine, loratadine, desloratadine, fexofenadine, astemizole, azelastine, and chlorpheniramine.
The present invention still further relates to the combination of a compound of the invention together with a gastroprotective H 2 receptor antagonist.
The present invention still further relates to the combination of a compound of the invention together with an α 1 - and α 2 -adrenoceptor agonist vasoconstrictor sympathomimetic agent, including propylhexedrine, phenylephrine, phenylpropanolamine, pseudoephedrine, naphazoline hydrochloride, oxymetazoline hydrochloride, tetrahydrozoline hydrochloride, xylometazoline hydrochloride, and ethylnorepinephrine hydrochloride.
The present invention still further relates to the combination of a compound of the invention together with anticholinergic agents including ipratropium bromide; tiotropium bromide; oxitropium bromide; pirenzepine; and telenzepine.
The present invention still further relates to the combination of a compound of the invention together with a β 1 - to β 4 -adrenoceptor agonists including metaproterenol, isoproterenol, isoprenaline, albuterol, salbutamol, formoterol, salmeterol, terbutaline, orciprenaline, bitolterol mesylate, and pirbuterol; or methylxanthanines including theophylline and aminophylline; sodium cromoglycate; or muscarinic receptor (M1, M2, and M3) antagonist.
The present invention still further relates to the combination of a compound of the invention together with an insulin-like growth factor type I (IGF-1) mimetic.
The present invention still further relates to the combination of a compound of the invention together with an inhaled glucocorticoid with reduced systemic side effects, including prednisone, prednisolone, flunisolide, triamcinolone acetonide, beclomethasone dipropionate, budesonide, fluticasone propionate, and mometasone furoate.
The present invention still further relates to the combination of a compound of the invention together with (a) tryptase inhibitors; (b) platelet activating factor (PAF) antagonists; (c) interleukin converting enzyme (ICE) inhibitors; (d) IMPDH inhibitors; (e) adhesion molecule inhibitors including VLA-4 antagonists; (f) cathepsins; (g) MAP kinase inhibitors; (h) glucose-6 phosphate dehydrogenase inhibitors; (i) kinin-B 1 - and B 2 -receptor antagonists; (j) anti-gout agents, e.g., colchicine; (k) xanthine oxidase inhibitors, e.g., allopurinol; (l) uricosuric agents, e.g., probenecid, sulfinpyrazone, and benzbromarone; (m) growth hormone secretagogues; (n) transforming growth factor (TGFβ); (o) platelet-derived growth factor (PDGF); (p) fibroblast growth factor, e.g., basic fibroblast growth factor (bFGF); (q) granulocyte macrophage colony stimulating factor (GM-CSF); (r) capsaicin cream; (s) Tachykinin NK 1 and NK 3 receptor antagonists selected from the group consisting of NKP-608C; SB-233412 (talnetant); and D-4418; and (t) elastase inhibitors selected from the group consisting of UT-77 and ZD-0892.
The present invention still further relates to the combination of a compound of the invention together with an inhibitor of matrix metalloproteases (MMPs), i.e., the stromelysins, the collagenases, and the gelatinases, as well as aggrecanase; especially collagenase-1 (MMP-1), collagenase-2 (MMP-8), collagenase-3 (MMP-13), stromelysin-1 (MMP-3), stromelysin-2 (MMP-10), and stromelysin-3 (MMP-11).
The compounds of the invention can also be used in combination with existing therapeutic agents for the treatment of osteoarthritis. Suitable agents to be used in combination include standard non-steroidal anti-inflammatory agents (hereinafter NSAID's) such as piroxicam, diclofenac, propionic acids such as naproxen, flubiprofen, fenoprofen, ketoprofen and ibuprofen, fenamates such as mefenamic acid, indomethacin, sulindac, apazone, pyrazolones such as phenylbutazone, salicylates such as aspirin, COX-2 inhibitors such as celecoxib, valdecoxib, rofecoxib and etoricoxib, analgesics and intraarticular therapies such as corticosteroids and hyaluronic acids such as hyalgan and synvisc.
The compounds of the present invention may also be used in combination with anticancer agents such as endostatin and angiostatin or cytotoxic drugs such as adriamycin, daunomycin, cis-platinum, etoposide, taxol, taxotere and farnesyl transferase inhibitors, VegF inhibitors, COX-2 inhibitors and antimetabolites such as methotrexate antineoplastic agents, especially antimitotic drugs including the vinca alkaloids such as vinblastine and vincristine.
The compounds of the invention may also be used in combination with antiviral agents such as Viracept, AZT, aciclovir and famciclovir, and antisepsis compounds such as Valant.
The compounds of the present invention may also be used in combination with cardiovascular agents such as calcium channel blockers, lipid lowering agents such as statins, fibrates, beta-blockers, Ace inhibitors, Angiotensin-2 receptor antagonists and platelet aggregation inhibitors.
The compounds of the present invention may also be used in combination with CNS agents such as antidepressants (such as sertraline), anti-Parkinsonian drugs (such as deprenyl, L-dopa, Requip, Mirapex, MAOB inhibitors such as selegine and rasagiline, comP inhibitors such as Tasmar, A-2 inhibitors, dopamine reuptake inhibitors, NMDA antagonists, Nicotine agonists, Dopamine agonists and inhibitors of neuronal nitric oxide synthase), and anti-Alzheimer's drugs such as donepezil, tacrine, COX-2 inhibitors, propentofylline or metryfonate.
The compounds of the present invention may also be used in combination with osteoporosis agents such as roloxifene, droloxifene, lasofoxifene or fosomax and immunosuppressant agents such as FK-506, rapamycin, cyclosporine, azathioprine, and methotrexate.
DETAILED DESCRIPTION OF THE INVENTION
Compounds of the formula I may be prepared according to the following reaction schemes and discussion. Unless otherwise indicated A, X, Y, Z, n, q, s, t, and R 1 through R 12 and structural formula I in the reaction schemes and discussion that follow are as defined above.
Scheme 1 refers to the preparation of compounds of formula I. Compounds of formula I, wherein A is —(C═O)—NH—, can be prepared from compounds of formula II, wherein L is a halo or an anhydride leaving group of the formula R—(C═O)—O— wherein R is optionally substituted alkyl or aryl, by reaction with a compound of formula III
H 2 N—R 3 III
in the presence of a base. Suitable bases include an excess of compound of formula III as well as triethylamine, dimethylaminopyridine, sodium carbonate, pyridine, and Hünigs base, preferably triethylamine. The aforesaid reaction may be performed neat or in the presence of a solvent. Suitable solvents include methylene chloride, tetrahydrofuran, and toluene, preferably methylene chloride.
Alternatively, compounds of formula I, wherein A is —C═ONH—, can be prepared from compounds of formula IV, by reaction with a compound of formula III in the presence of a coupling reagent, such as 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide (EDC) or dicyclohexyl carbodiimide (DCC) and hydroxybenzotriazole hydrate (HOBt), and a base, such as diisopropylethylamine (DIEA) or triethylamine, in an aprotic solvent, such as methylene chloride. Suitable solvents include methylene chloride and dimethyl formamide, preferably methylene chloride. The aforesaid reaction may be run at a temperature from about 0° C. to about 50° C., for a period from about 1 hour to about 16 hours (as illustrated in Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc. (1989) pp. 972–976).
Compounds of formula I, wherein A is —NH—(C═O)—, may be prepared from compounds of formula V by reaction with a compound of the formula VI
wherein L′ is a leaving group such as chloro, fluoro, bromo, iodo or an anhydride leaving group of the formula R—(C═O)—O—, wherein R is optionally substituted alkyl or aryl. The aforesaid reaction may be conducted in the presence of a suitable base. Suitable bases include an excess of compound of formula V as well as triethylamine, dimethylaminopyridine, sodium carbonate, pyridine, and Hünigs base, preferably triethylamine. The aforesaid reaction may be performed neat or in the presence of a solvent at a temperature from about 0° C. to about 50° C., for a period from about 10 minutes to about 16 hours. Suitable solvents include methylene chloride, tetrahydrofuran, and toluene, preferably methylene chloride.
Compounds of formula II and IV can be made according to the methods of Scheme 2.
Compounds of formula V can be made according to the methods of Scheme 3.
Scheme 2 refers to the preparation of compounds of formulae IV and II, wherein L is a leaving group and R 1 is nitrogen linked (C 1 –C 10 )heterocyclyl. Compounds of formulae II and IV can be converted into compounds of formula I according to the methods of Scheme 1.
Referring to Scheme 2, a compound of the formula IV can be prepared from a compound of the formula II, wherein L is a leaving group such as a methyl or ethyl ester, by reaction with a saponification reagent such as with an aqueous base, such as sodium hydroxide in an alcoholic solvent such as methanol, ethanol or tert.-butanol. The aforesaid reaction may be run at a temperature from about 0° C. to about 100° C., for a period from about 1 hour to about 24 hours. When L is a leaving group such as tert.-butyl ester, a compound of the formula IV can be prepared by the reaction of a compound of formula II with an acid such as hydrochloric acid in a solvent such as dioxane at a temperature between 25° C. to about 80° C., for a period from about 10 minutes to about 6 hours.
A compound of the formula II, wherein L is a leaving group such as alkoxy, and R 1 is nitrogen linked (C 1 –C 10 )heterocyclyl, can be prepared from a compound of the formula VII by reaction with a compound of the formula
wherein d is 1 to 8 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond; W is >C═O or >SO 2 ; and each L 2 is independently hydrogen, (C 1 –C 6 )alkyl or halo; under reductive amination conditions. The reductive amination is typically carried out with a reducing agent, such as sodium cyanoborohydride or sodium triacetoxyborohydride, preferably at a pH of between 6 and 8. The reaction is normally performed in a protic solvent, such as methanol or ethanol, or in a mixture of solvents, such as dichloroethane/methanol, at temperature of about −78° C. to about 40° C. for a period from about 1 hour to about 24 hours. (See A. Abdel-Magid, C. Maryanoff, K. Carson, Tetrahedron Lett ., Vol. 34, Issue 31, 5595–98, 1990). Other conditions involve the use of titanium isopropoxide and sodium cyanoborohydride (R. J. Mattson et al., J. Org. Chem., 1990, 55, 2552–4) or involve the formation of the imine under dehydrating conditions followed by reduction ( Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc (1989) pp. 421–425).
Alternatively, a compound of the formula II, wherein L is a leaving group such as alkoxy, and R 1 is (C 1 –C 10 )heterocyclyl wherein the bridgehead atom is nitrogen, can be prepared from the diazonium intermediate derived from a compound of the formula VII. The diazonium intermediate is prepared by reaction of a compound of the formula VII with an acid such as hydrochloric acid followed by treatment with sodium nitrite in a solvent such as glacial acetic acid at a temperature from about 0° C. to about 30° C., and the reaction is generally run for a period of about 30 min to about 3 hours. The compound of the formula II is prepared by the reaction of the above diazonium intermediate with a compound of the formula VIII wherein d is 1 to 8 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with either an oxo group or a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond; W is >C═O or >SO 2 ; and each L 2 is independently alkoxy or halo; under basic conditions. The reaction is typically carried out with sodium acetate as base at a temperature from about 0° C. to about 120° C., and the reaction is generally run for a period of about 1 hour to about 24 hours. (For example, see R. D. Carroll et al., J. Med. Chem., 1983, 26, 96–100).
Alternatively, one skilled in the art will also appreciate that a compound of formula II wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocycle, can be prepared by standard synthetic methods from a compound of the formula VII, wherein L is a protecting group such as alkoxy, by reaction with a bidentate reagent wherein two different transformable groups exist, such as an alkylating and acylating group of the formula
wherein L is a leaving group such as halo, L 2 is hydrogen, (C 1 –C 6 )alkyl, hydroxy, (C 1 –C 6 )alkoxy or halo; W is >C═O or >SO 2 ; d is 1 to 9 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond.
Alternatively, one skilled in the art will also appreciate that a compound of formula II wherein R 1 is an nitrogen linked (C 1 –C 10 )heterocycle, can be prepared by standard synthetic methods from a compound of the formula VII, wherein L is a protecting group such as alkoxy, by reaction with an anhydride reagent of the formula
wherein d is 1 to 9 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond.
Compounds of the formula VII can be prepared from compounds of the formula XI by reaction with an alcohol of the formula ROH, wherein R is optionally substituted (C 1 –C 4 )alkyl or (C 6 –C 10 )aryl, in the presence of an acid (a so called Fischer esterification) or a coupling reagent, such as 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide (EDC) or dicyclohexyl carbodiimide (DCC) and hydroxybenzotriazole hydrate (HOBt), and a base, such as diisopropylethylamine (DIEA) or triethylamine, in an aprotic solvent, such as methylene chloride. Suitable solvents include methylene chloride and dimethyl formamide, preferably methylene chloride. The aforesaid reaction may be run at a temperature from about 0° C. to about 50° C., for a period from about 1 hour to about 16 hours (as illustrated in Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc. (1989) pp. 972–976).
Compounds of the formulae VIII, IX, X and XI are commercially available or can be made by methods well known to those of ordinary skill in the art.
Scheme 3 refers to the preparation of the compounds of formula V which are intermediates useful in the preparation of compound of formula I, in Scheme 1. Referring to Scheme 3, a compound of formula V is prepared by reduction of a compound of the formula XII. Reduction may be effected with hydrogen gas (H 2 ), using catalysts such as palladium on carbon (Pd/C), palladium on barium sulfate (Pd/BaSO 4 ), platinum on carbon (Pt/C), or tris(triphenylphosphine) rhodium chloride (Wilkinson's catalyst), in an appropriate solvent such as methanol, ethanol, THF, dioxane or ethyl acetate, at a pressure from about 1 to about 5 atmospheres and a temperature from about 10° C. to about 60° C., as described in Catalytic Hydrogenation in Organic Synthesis , Paul Rylander, Academic Press Inc., San Diego, 31–63 (1979). The following conditions are preferred: Pd on carbon, methanol at 25° C. and 50 psi of hydrogen gas pressure.
An alternative procedure employing the use of reagents such as ammonium formate and Pd/C in methanol at the reflux temperature under an inert atmosphere (e.g., nitrogen or argon gas) is also effective.
Another alternative reduction procedure, for use when R 1 contains a group incompatible with the above hydrogenation conditions (e.g., an olefin or halide group), is a dissolving metal reduction wherein the compound of formula XII is treated with a metal, such as zinc, tin or iron, in the presence of an acid such as hydrochloric or sulfuric acid. The aforesaid reaction may be run at a temperature from about 0° C. to about 100° C., for a period from about 1 hour to about 16 hours.
Compounds of the formula XII can be prepared from compounds of formula XIII by reaction with reagents of the formulae VIII, IX and X as described previously in Scheme 2 for the conversion of a compound of formula VII to II.
The starting materials of the formula XIII are either commercially available or known in the art.
Scheme 4 refers to alternate preparations of compounds of formula I.
Referring to Scheme 4, compounds of the formula I, wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl, can be prepared by an aryl palladium coupling reaction. Aryl palladium coupling reactions are well known to those skilled in the art. One well known coupling method, so called Buchwald and Hartwig conditions, involves the coupling of a compound of formula XIV, wherein L 2 is Cl, Br, I or triflate (TfO), with a compound of the formula R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, in the presence of a palladium (0) catalyst and a base. Palladium (0) catalysts include tris(dibenzylidene acetone)dipalladium(O) (Pd 2 (dba) 3 ), di(dibenzylidene acetone) palladium(O) (Pd(dba) 2 ), palladium acetate (Pd(OAc) 2 , and a suitable ligand, such as a triaryl phosphine ligand, tri(t-butyl)phosphine, 1,1′-bis(diphenylphosphanyl)ferrocene (DPPF), 2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl (BINAP), or PHANEPHOS, preferably tri(ortho-tolyl)phosphine. Suitable bases include K 2 CO 3 , K 2 PO 4 , CsCO 3 , LiN(TMS) 2 or an alkoxide base such as sodium methoxide, sodium ethoxide, potassium t-butoxide, preferably sodium tert-butoxide. Suitable solvents include toluene or an ethereal solvent, preferably dioxane. The aforesaid reaction may be run at a temperature of about 40° C. to 110° C. for about 1 to 48 hours. Such conditions are reviewed in Angew. Chem. Int. Ed. Engl. 1998, 37, 2046–2067 and are well known to those of ordinary skill in the art. Preferred Buchwald conditions use palladium acetate (Pd(OAc) 2 ) or palladium tetra-triphenylphosphine (Pd(PPh 3 ) 4 ) as the source of the palladium. Suitable solvents include THF, toluene or ethereal solvents. The aforesaid reaction may be run at a temperature of about 25° C. to 110° C. for about 1 to 4 hours, preferably 2 hours. Nickel catalysts, such as Ni(cod) (nickel 1,5-cyclooctadiene), are also well known.
Alternatively, compounds of formula I, can be prepared according to a so called Ullmann reaction by reaction of a compound of the formula XIV, wherein L 2 is a halide, with a compound of the formula R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, in the presence of a suitable base and a suitable catalyst. Suitable bases include alkali metal carbonates or hydroxide bases, preferably potassium carbonate. Suitable catalysts include copper (0) catalyst, preferably finely powdered copper bronze. Suitable solvents for the aforesaid reaction include neat or polar aprotic solvents, such as dimethylformamide (DMF), N,N dimethylacetamide or N-methylpyrrolidinone (NMP). The aforesaid reaction may be run at a temperature between about 80° C. and 180° C. for about 6 to 24 hours.
Alternatively, coupling can be carried out by a so called Suzuki coupling reaction of said compound of formula XIV, wherein L 2 is borate or boronic acid, with an R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, a catalyst, a base and a dehydrating agent. Suitable borates include (HO) 2 B—, 9-BBN, and alkylboranes. Suitable catalysts include copper or palladium (such as palladium acetate (Pd(OAc) 2 ), palladium triphenylphosphine or Pd(dppf)Cl 2 ), preferably copper (II) acetate. Suitable dehydrating agents include 4 angstrom molecular sieves. Suitable bases include tertiary amine bases, such as triethylamine or pyridine, Na 2 CO 3 , sodium ethoxide, and K 3 PO 4 . Suitable solvents include methylene chloride, dimethyl sulfoxide (DMSO) or tetrahydrofuran (THF). The aforesaid reaction is typically performed under an atmosphere of oxygen gas at a temperature of about 10° C. to 50° C., preferably about 23° C. for about 6 to 72 hours. Palladium-catalyzed boronic acid couplings are described in Miyaura, N., Yanagi, T., Suzuki, A. Syn. Comm. 1981, 11, 7, p. 513.
Alternatively, compounds of formula I can also be prepared from compounds of formula XV or XVI via intermediates of the formula II and XII. The intermediates of the formula II and XII can be converted to compounds of formula I according to the methods of Schemes 1 and 3 respectively. The compounds of formulae II and XII can be prepared from compounds of the formulae XV and XVI, respectively, by coupling reactions analogous to those described above for the conversion of compounds of formula XIV to formula I.
Compounds of formula XIV can be prepared from compounds of formula XV or XVI by methods analogous to the conversion of compounds of formula II to I and XII to I.
Compounds of the formula XV and XVI are commercially available or can be made by methods well known to those skilled in the art.
Scheme 5 refers to an alternate preparation of compounds of formula I. Referring to Scheme 5, a compound of formula I is prepared from a compound of formula XVII by reduction with tin in the presence of an acid such as hydrochloric acid followed by a so called Sandmeyer reaction wherein a diazonium intermediate is prepared by treatment with sodium nitrite followed by cuprous halide quench such as cuprous chloride or cuprous bromide. Suitable solvents include alcohols such as methanol and ethanol. The aforesaid reaction is conducted at a temperature from about −20° C. to about 0° C., and the reaction is generally run for a period of about 1 to 48 hours.
The compound of formula XVII, wherein R 1 is a standard transformable group, such a —NH 2 , or a heterocycle can be prepared from a compound of the formula XVIII by reaction with a nucleophile according to standard chemical methods well known to those skilled in the art. Methods for nucleophilic aromatic substitution are reviewed in Belfield et al., Tetrahedron, 55, 11399–11428 (1999) and in March, Advanced Organic Chemistry, 641–676 (John Wiley & Sons, Inc., Fourth Edition, 1992).
Other compounds of formula XVII, wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl containing one to six heteroatoms independently selected from —N═, —N<, —NH—, —O— and —S(O) n —; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl is substituted by at least one oxo substituent; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any carbon atom able to support an additional substituent, by one to three R 9 substituents per ring, each R 9 is independently selected from the group consisting of hydrogen, halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, HO 2 C—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(O═C)—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, R 4 R 5 N(CH 2 ) t —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said (C 1 –C 10 )heterocyclyl may also optionally be substituted on any ring nitrogen atom able to support an additional substituent by one to two R 10 substituents per ring, each R 10 is independently selected from the group consisting of hydrogen, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 9 and R 10 group members or substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, —(C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—; can be prepared by standard conversion methods from compounds of formula XVII, wherein R 1 is a standard transformable group.
Compounds of formula XVIII are commercially available or can be made by methods known to those skilled in the art.
Alternatively, compounds of formula I and II can be prepared from compounds of formula XX by analogous Sandmeyer methods as described above.
Compounds of formula XX can be prepared from compounds of formula XXI by methods analogous to the conversion of compounds of formula XVIII to XVII described above.
Compounds of formula XXI are commercially available or can be made by methods well known to those skilled in the art.
The compounds of the formula I which are basic in nature are capable of forming a wide variety of different salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to initially isolate a compound of the formula I from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert the latter back to the free base compound by treatment with an alkaline reagent, and subsequently convert the free base to a pharmaceutically acceptable acid addition salt. The acid addition salts of the base compounds of this invention are readily prepared by treating the base compound with a substantially equivalent amount of the chosen mineral or organic acid in an aqueous solvent medium or in a suitable organic solvent such as methanol or ethanol. Upon careful evaporation of the solvent, the desired solid salt is obtained.
The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as chloride, bromide, iodide, nitrate, sulfate or bisulfate, phosphate or acid phosphate, acetate, lactate, citrate or acid citrate, tartrate or bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate and pamoate [i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)] salts.
Those compounds of the formula I which are also acidic in nature, e.g., where R 4 includes a 6-azauracil or barbituric acid moiety, are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include the alkali metal or alkaline-earth metal salts and particularly, the sodium and potassium salts. These salts are all prepared by conventional techniques. The chemical bases which are used as reagents to prepare the pharmaceutically acceptable base salts of this invention are those which form non-toxic base salts with the herein described acidic compounds of formula I. These non-toxic base salts include those derived from such pharmacologically acceptable cations as sodium, potassium, calcium and magnesium, etc. These salts can easily be prepared by treating the corresponding acidic compounds with an aqueous solution containing the desired pharmacologically acceptable cations, and then evaporating the resulting solution to dryness, preferably under reduced pressure. Alternatively, they may also be prepared by mixing lower alkanolic solutions of the acidic compounds and the desired alkali metal alkoxide together, and then evaporating the resulting solution to dryness in the same manner as before. In either case, stoichiometric quantities of reagents are preferably employed in order to ensure completeness of reaction and maximum product yields.
The activity of the compounds of the invention for the various disorders described above can be determined according to one or more of the following assays. All of the compounds of the invention, that were tested, had an IC 50 of less than 1 μM in the in vitro assay described below.
Pharmacological Analysis
Certain compounds such as benzoylbenzoyl adenosine triphosphate (bbATP) are known to be agonists of the P2X 7 receptor, effecting the formation of pores in the plasma membrane (Drug Development Research (1996), 37(3), p. 126). Consequently, when the receptor is activated using bbATP in the presence of ethidium bromide (a fluorescent DNA probe), an increase in the fluorescence of intracellular DNA-bound ethidium bromide is observed. Alternatively, the propidium dye YOPRO-1 can be substituted for ethidium bromide so as to detect uptake of the dye. The increase in fluorescence can be used as a measure of P2X 7 receptor activation and therefore to quantify the effect of a compound on the P2X 7 receptor.
In this manner, the compounds of the invention can be tested for antagonist activity at the P2X 7 receptor. 96-Well flat bottomed microtitre plates are filled with 250 μl of test solution comprising 200 μl of a suspension of THP-1 cells (2.5×10 6 cells/ml, more preferably prestimulated as described in the literature with a combination of LPS and TNF to promote receptor expression) containing 10 −4 M ethidium bromide, 25 μl of a high potassium, Low Sodium Buffer Solution (10 mM Hepes, 150 mM KCl, 5 mM D-glucose and 1.0% FBS at pH 7.5) containing 10 −5 M bbATM, and 25 μl of the high potassium buffer solution containing 3×10 −5 M test compound (more preferably 5×10 −4 M, more preferably 1×10 −4 M, more preferably 1×10 −3 M). The plate is covered with a plastic sheet and incubated at 37° C. for one hour. The plate is then read in a Perkin-Elmer fluorescent plate reader, excitation 520 nm, emission 595 nm, slit widths: Ex 15 nm, Em 20 nm. For the purposes of comparison, bbATP (a P2X 7 receptor agonist) and pyridoxal 5-phosphate (a P2X 7 receptor antagonist) can be used separately in the test as controls. From the readings obtained, a pIC 50 figure can be calculated for each test compound, this figure being the negative logarithm of the concentration of test compound necessary to reduce the bbATP agonist activity by 50%.
In like manner, the compounds of the invention can be tested for antagonist activity at the P2X 7 receptor using the cytokine IL-1 β as the readout. Blood collected from normal volunteers in the presence of heparin is fractionated using lymphocyte separation medium obtained from Organon Technica (Westchester, Pa.). The region of the resulting gradient containing banded mononuclear cells is harvested, diluted with 10 ml of Maintenance Medium (RPMI 1640, 5% FBS, 25 mM Hepes, pH 7.2, 1% penicillin/streptomycin), and cells are collected by centrifugation. The resulting cell pellet was suspended in 10 ml of Maintenance Medium and a cell count was performed. In an average experiment, 2×10 5 mononuclear cells are seeded into each well of 96-well plates in a total volume of 0.1 ml. Monocytes are allowed to adhere for 2 hours, after which the supernatants are discarded and the attached cells are rinsed twice and then incubated in Maintenance Medium overnight at 37° C. in a 5% CO 2 environment.
The cultured monocytes can be activated with 10 ng/ml LPS ( E. coli serotype 055:B5; Sigma Chemicals, St. Louis, Mo.). Following a 2-hour incubation, the activation medium is removed, the cells are rinsed twice with 0.1 ml of Chase Medium (RPMI 1640, 1% FBS, 20 mM Hepes, 5 mM NaHCO 3 , pH 6.9), and then 0.1 ml of Chase Medium containing a test agent is added and the plate is incubated for 30 minutes; each test agent concentration can be evaluated in triplicate wells. ATP then is introduced (from a 100 mM stock solution, pH 7) to achieve a final concentration of 2 mM and the plate is incubated at 37° C. for an additional 3 hours. Media were harvested and clarified by centrifugation, and their IL-1β content was determined by ELISA (R&D Systems; Minneapolis, Minn.).
The compositions of the present invention may be formulated in a conventional manner using one or more pharmaceutically acceptable carriers. Thus, the active compounds of the invention may be formulated for oral, buccal, intranasal, parenteral (e.g., intravenous, intramuscular or subcutaneous), topical or rectal administration or in a form suitable for administration by inhalation or insufflation.
For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinized maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolate); or wetting agents (e.g., sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters or ethyl alcohol); and preservatives (e.g., methyl or propyl p-hydroxybenzoates or sorbic acid).
For buccal administration, the composition may take the form of tablets or lozenges formulated in conventional manner.
The compounds of formula I can also be formulated for sustained delivery according to methods well known to those of ordinary skill in the art. Examples of such formulations can be found in U.S. Pat. Nos. 3,538,214, 4,060,598, 4,173,626, 3,119,742, and 3,492,397, which are herein incorporated by reference in their entirety.
The active compounds of the invention may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.
The active compounds of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
For intranasal administration or administration by inhalation, the active compounds of the invention are conveniently delivered in the form of a solution, dry powder formulation or suspension from a pump spray container that is squeezed or pumped by the patient or as an aerosol spray presentation from a pressurized container or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, heptafluoroalkanes, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container or nebulizer may contain a solution or suspension of the active compound. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.
A proposed dose of the active compounds of the invention for oral, parenteral or buccal administration to the average adult human for the treatment of the conditions referred to above (inflammation) is 0.1 to 200 mg of the active ingredient per unit dose which could be administered, for example, 1 to 4 times per day.
The compound of formula (I) and pharmaceutically acceptable salts and solvates thereof may be used on their own but will generally be administered in the form of a pharmaceutical composition in which the formula (I) compound/salt/solvate (active ingredient) is in association with a pharmaceutically acceptable adjuvant, diluent or carrier. Depending on the mode of administration, the pharmaceutical composition will preferably comprise from 0.05 to 99% w (percent by weight), more preferably from 0.10 to 70% w, of active ingredient, and, from 1 to 99.95% w, more preferably from 30 to 99.90% w, of a pharmaceutically acceptable adjuvant, diluent or carrier, all percentages by weight being based on total composition.
Aerosol formulations for treatment of the conditions referred to above in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains 20 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
Aerosol combination formulations for treatment of the conditions referred to above (e.g., adult respiratory distress syndrome) in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains from about 1 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
Aerosol formulations for treatment of the conditions referred to above (e.g., adult respiratory distress syndrome) in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains from about 20 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg of the p38 kinase inhibitor. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
This invention also encompasses pharmaceutical compositions containing and methods of treating or preventing comprising administering prodrugs of compounds of the formula I. Compounds of formula I having free amino, amido, hydroxy or carboxylic groups can be converted into prodrugs. Prodrugs include compounds wherein an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues which are covalently joined through peptide bonds to free amino, hydroxy or carboxylic acid groups of compounds of formula I. The amino acid residues include the 20 naturally occurring amino acids commonly designated by three letter symbols and also include, 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline homocysteine, homoserine, ornithine and methionine sulfone. Prodrugs also include compounds wherein carbonates, carbamates, amides and alkyl esters which are covalently bonded to the above substituents of formula I through the carbonyl carbon prodrug sidechain.
The following Examples illustrate the preparation of the compounds of the present invention. Melting points are uncorrected. NMR data are reported in parts per million (d) and are referenced to the deuterium lock signal from the sample solvent (deuteriochloroform unless otherwise specified). Mass Spectral data were obtained using a Micromass ZMD APCI Mass Spectrometer equipped with a Gilson gradient high performance liquid chromatograph. The following solvents and gradients were used for the analysis. Solvent A; 98% water/2% acetonitrile/0.01% formic acid and solvent B; acetonitrile containing 0.005% formic acid. Typically, a gradient was run over a period of about 4 minutes starting at 95% solvent A and ending with 100% solvent B. The mass spectrum of the major eluting component was then obtained in positive or negative ion mode scanning a molecular weight range from 165 AMU to 1100 AMU. Specific rotations were measured at room temperature using the sodium D line (589 nm). Commercial reagents were utilized without further purification. THF refers to tetrahydrofuran. DMF refers to N,N-dimethylformamide. Chromatography refers to column chromatography performed using 32–63 mm silica gel and executed under nitrogen pressure (flash chromatography) conditions. Room or ambient temperature refers to 20–25° C. All non-aqueous reactions were run under a nitrogen atmosphere for convenience and to maximize yields. Concentration at reduced pressure means that a rotary evaporator was used.
One of ordinary skill in the art will appreciate that in some cases protecting groups may be required during preparation. After the target molecule is made, the protecting group can be removed by methods well known to those of ordinary skill in the art, such as described in Greene and Wuts, “Protective Groups in Organic Synthesis” (2 nd Ed, John Wiley & Sons 1991).
EXAMPLE 1
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-hexyl)-benzamide
A: 2-(3-Carboxy-4-chloro-phenyl)-3,5-dioxo-2,3,4,5-tetrahydro-[1,2,4]triazine-6-carboxylic acid
To a mechanically stirred solution of 5-amino-2-chloro-benzoic acid methyl ester (5.0 g, 26.9 mmol) in glacial acetic acid (100 ml) was added 12 N hydrochloric acid (7.5 ml). After 30 minutes at room temperature the reaction mixture was cooled to 10° C. and a solution of NaNO 2 in water (5 ml) was added dropwise at a rate that kept the reaction temperature between 10° and 15° C. During this time it was observed that the reaction went from purple to light brown. After stirring for 30 minutes at 10° C. sodium acetate (5.4 g) followed by (3-ethoxycarbonylamino-3-oxo-propionyl)-carbamic acid ethyl ester (7.2 g) were added at once. After stirring for 20 minutes at 10° C. followed by 1 hour at room temperature an additional 2.2 g of sodium acetate was added. After stirring at reflux for 6 hours the reaction mixture was cooled to room temperature and 50% aqueous sulfuric acid (29 ml) was added. After stirring the resulting mixture at reflux for 2 hours the mixture was cooled to room temperature, diluted with water (135 ml) and filtered. The precipitate was washed with water and dried under vacuum. The crude solid was recrystallized from isopropyl ether to give 3.8 g (46%) of the title intermediate as an orange solid. Mass spec [M−1] 3:1 ratio of 310.1 and 312.1; 1 H nmr (500 MHz, CD 3 OD) δ 7.64 (d, J=8.8 Hz, 1H), 7.75 (d, J=8.8 Hz, 1H), 8.14 (d, J=2.6 Hz, 1H).
B: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid
A suspension of 2-(3-carboxy-4-chloro-phenyl)-3,5-dioxo-2,3,4,5-tetrahydro-[1,2,4]triazine-6-carboxylic acid (3.4 g) in mercaptoacetic acid (2 ml) was stirred at 175° C. After 20 h the resulting solution was cooled to room temperature during which time a precipitate formed. The mixture was dumped into ice-water, stirred for 30 minutes and filtered to give a yellow solid. The solid was dried under vacuum for 24 hours to give 2.1 g of the title intermediate. Mass spectrum [M−1] 3:1 ratio of 266.1 and 268.1; 1 H nmr (500 MHz, CD 3 OD) δ 7.58 (s, 1H), 7.60 (d, J=8.8 Hz, 1H), 7.72 (dd, J=2.6 and 8.8 Hz), 8.09 (d, J=2.6 Hz).
C: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoyl chloride
A mixture of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid (50 mg) in thionyl chloride (1 ml) was stirred at reflux for 1 hour. The mixture was concentrated under vacuum to provide 50 mg of the title intermediate as an amorphous amber solid that was used immediately in the next step.
D: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-hexyl)-benzamide
To a solution of 2-ethylhexylamine (15 mg, 0.125 mmol) in dichloroethane (1 ml) was added diisopropylethylamine resin (60 mg, 0.225 mmol) followed by a solution of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoyl chloride (21 mg, 0.075 mmol) in a 3:1 mixture of dichloroethane and THF (15 ml). The reaction mixture was shaken for 16 hours and filtered. The filtrate was treated with MP-carbonate resin (75 mg, 0.225 mmol) and the resulting mixture was shaken for 3 hours. The mixture was filtered and the resin washed with dichloromethane followed by 9:1 methanol/acetic acid. The combined filtrates were concentrated under reduced pressure to give the title compound as an amorphous solid. Mass spec [M−1] 3:1 ratio of 377.2 and 379.2; 1 H nmr (500 MHz, CDCl 3 ) δ 0.92 (t, 3H), 0.96 (t, 3H), 1.26–1.66 (m, 9H), 3.46 (m, 2H), 6.26 (broad s, 1H), 7.51 (d, 1H), 7.59–7.62 (m, 2H), 7.94 (s, 1H), 8.72 (broad s, 1H).
Examples 2–44 are presented in Table 1 and were prepared analogously to the synthesis outlined in Example 1D, coupling the appropriate amine to 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoyl chloride. In some examples the product was purified by preparative HPLC using a Shimadsu LC-8A preparative liquid chromatograph. All final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A = 98% Water + 2% Acetonitrile + 0.01% Formic Acid
Solvent B = Acetonitrile + 0.005% Formic Acid
TABLE 1
Mass Spectra
Mass Spectra
LC Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
2
351.2
349.2
2.2
3
399.1
397.0
2.4
4
405.0
403.0
2.3
5
371.1
369.0
2.0
6
451.0
448.9
2.3
7
389.1
387.0
2.1
8
441.0
436.9
2.3
9
401.1
399.0
2.2
10
405.0
403.0
2.2
11
337.1
335.1
2.1
12
389.1
387.0
2.0
13
447.1
445.0
2.4
14
415.1
413.0
2.3
15
481.0
479.0
2.3
16
379.2
377.1
2.7
17
405.0
403.0
2.2
18
439.0
438.9
2.5
19
351.2
349.1
2.3
20
389.1
387.0
2.1
21
363.2
361.1
2.2
22
441.0
439.0
2.4
23
385.1
383.0
2.3
24
377.1
375.0
1.9
25
421.7
419.8
2.0
26
375.6
373.7
2.4
27
421.9
419.6
2.1
28
375.8
373.8
2.4
29
385.2
383.1
2.2
30
421.1
419.1
1.9
31
405.2
403.1
1.7
32
429.2
427.1
2.0
33
477.2
475.2
2.6
34
403.3
401.2
2.6
35
387.2
385.1
1.5
36
413.2
411.1
2.0
37
417.2
415.1
2.2
38
401.2
399.1
2.0
39
403.3
401.2
2.6
40
439.3
437.2
2.6
41
401.5
399.6
2.1
42
481.5
479.5
2.2
43
453.3
451.2
2.8
44
425.3
423.2
2.5
45
510.1
508.1
2.4
46
475.2
473.2
2.2
47
429.5
427.5
2.7
EXAMPLE 48
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-benzamide
To a stirred solution of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid (75 mg, 0.3 mmol), EDCI (60 mg) and HOBT (50 mg) in DMF (3 ml) was added 2-(2-trifluoromethylphenyl)ethylamine (53 mg, 0.3 mmol). After 30 minutes triethylamine (45 μl) was added. After 3 hours the reaction mixture was diluted with ethyl acetate (75 ml) and washed sequentially with water and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated under vacuum to give 73 mg of an amorphous solid. The solid was purified by silica gel chromatography eluting with 1:1 ethylacetate/hexanes, followed by crystallization from isopropyl ether to give 36 mg of the title compound as a white solid.
Melting Point=148–150° C.; Mass spectra [M−1] 437.6; Mass spectra [M+1] 439.9.
Examples 49–50 are presented in Table 2 and were prepared analogously to the synthesis outlined in Example 48, coupling the appropriate amine to 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid. Final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A = 98% Water + 2% Acetonitrile + 0.01% Formic Acid
Solvent B = Acetonitrile + 0.005% Formic Acid
TABLE 2
Mass Spectra
Mass Spectra
LC Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
49
419.5
417.5
2.4
50
379.4
377.4
1.6
EXAMPLE 51
N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-benzamide
A: 2-Methyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid
5-Amino-2-chloro-benzoic acid methyl ester (3.5 g, 21.2 mmol) was dissolved in glacial acetic acid (80 ml) and 5.5 ml of concentrated HCl was added. After stirring with an overhead stirrer for 30 minutes at ambient temperature the mixture was cooled to 10° C. and a solution of NaNO 2 (1.6 g) in water (4 ml) was added dropwise, keeping the internal temperature below 15° C. During this addition the reaction mixture changed from amber to a cloudy orange. After 30 minutes sodium acetate (3.8 g, 46.6 mmol) and (3-ethoxycarbonylamino-3-oxo-propionyl)-carbamic acid ethyl ester (5.7 g, 23.3 mmol) were added at once. After 10 minutes the reaction was warmed to ambient temperature. After 1 hour additional sodium acetate (1.7 g, 21.2 mmol) was added and the reaction mixture was heated at reflux. After 3 hours the deep red-brown mixture was treated with 50% sulfuric acid (23 ml) and heated again at reflux. After 2 hours the mixture was concentrated under reduced pressure and then water (200 ml) was added. After stirring for 30 minutes the gold precipitate (3.5 g) was collected by filtration. The resulting solid was suspended in 3 ml of mercaptoacetic acid and stirred at 175° C. After 4 hours the mixture was allowed to cool and sit for 16 hours. The mixture was diluted with water (100 ml) and stirred for 1 hour. The resulting brown solid (2.1 g) was collected by filtration. Mass spectrum [M−1] 246.4.
B: N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,-dihyro-3H-[1,2,4]triazin-2-yl)-2-methyl-benzamide
The title compound was prepared using the method outlined in Example 48, coupling 2-methyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid with 2-(ortho-chlorophenyl)ethylamine. The product was a colorless oil. MS (ES+) 385.2; (ES−) 383.2; LC retention time=2.1 min (using the LC/MS and method outlined for the examples in Table 1).
EXAMPLE 52
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide
To a stirred solution of 2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide (70 mg, 0.173 mmol) in dioxane (1.5 ml) was added methanol (0.36 ml) followed by a 2.0 M solution of (trimethylsilyl)diazomethane (0.35 ml). After stirring for 16 hours at ambient temperature the mixture was concentrated under reduced pressure to give 75 mg of a white amorphous solid. Purification by silica gel chromatography eluting with 2:1 hexaned/ethyl acetate provided 39 mg of the title compound as a white amorphous solid. Melting Point 157–161° C.;
Mass Spectrum (ES+) 419.2; (ES−) 417.1; LC retention time=2.4 minutes (using the LC/MS and method outlined for the examples in Table 1).
EXAMPLE 53
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide
A: 5-Bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide
To a stirred solution of 2-chloro-5-bromobenzoic acid (1.5 g, 6.3 mmol), EDCI (1.63 g, 8.5 mmol), and HOBT (1.15 g, 8.5 mmol) in DMF (20 ml) was added 2-(2-chlorophenyl)ethylamine (1.06 ml, 7.5 mmol). After 15 minutes triethylamine (1.18 ml, 8.5 mmol) and DMF (5 ml) was added. After 2 hours at ambient temperature the mixture was diluted with ethyl acetate (50 ml) and washed with 1 N HCl followed by a saturated solution of sodium bicarbonate, followed by water, and then brine. The organic layer was separated and dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 2.12 g of an amorphous solid. Mass Spectrum (ES+) 374.6, (ES−) 372.2.
B: 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide
A mixture of 5-bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide (200 mg, 0.536 mmol), δ-valerolactam (106 mg, 1.07 mmol), potassium carbonate (156 mg, 1.13 mmol), dioxane (1 ml, purged with nitrogen), and copper (I) iodide (5 mg) in an oven-dried round bottom flask equipped with a reflux condenser under a nitrogen atmosphere was heated in an oil bath at 120–125° C. After 21 hours the mixture was cooled to room temperature, filtered through a pad of silica gel and concentrated under reduced pressure to give 50 mg of crude product. Purification by preparative HPLC (Shimadsu LC-8A preparative liquid chromatograph) eluting with a gradient of 0.1% aqueous formic acid in acetonitrile provided 2.5 mg of the title compound as a colorless amorphous solid. Mass Spectrum (ES+) 391.6; LC retention time=2.3 minutes (using the LC/MS and method outlined for the examples in Table 1).
Examples 54–57 are presented in Table 3 and were prepared analogously to the synthesis outlined in Example 53, coupling the appropriate lactam to 5-bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide. In some examples the product was purified by preparative HPLC using a Shimadsu LC-8A preparative liquid chromatograph. All final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A = 98% Water + 2% Acetonitrile + 0.01% Formic Acid
Solvent B = Acetonitrile + 0.005% Formic Acid
TABLE 3
Mass Spectra
Mass Spectra
LC Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
54
417.7
—
2.3
55
434.3
—
2.1
56
379.8
—
2.4
57
457.1
—
2.8
EXAMPLE 58
2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide
A: 2-Chloro-5-phenoxycarbonylamino-benzoic acid methyl ester
To a stirred mixture of 5-amino-2-chloro-benzoic acid methyl ester hydrochloride (1.110 g, 5.0 mmol) and pyridine (0.79 g, 10.0 mmol) in anhydrous THF (15 mL) at 0° C. was added phenylchloroformate (0.95 g, 6.0 mmol). After warming to room temperature, the reaction mixture was diluted with ethylacetate (50 mL), washed sequentially with 10% HCl, water and brine and dried over sodium sulfate. Removal of solvent under vacuum and purification of the product by flash chromatography (10% ethyl acetate in hexanes) yielded 0.8 g (53%) of a colorless solid. 1 H NMR (300 MHz, DMSO-d6) δ3.9 (s, 3H), 7.0 (br s, 1H), 7.18 (m, 2H), 7.4 (m, 3H), 7.6 (m, 1H), 7.9 (d, J=2.5 Hz, 1H). Mass Spectrum (M−H): 3:1 ratio of 304 and 306.
B: 1-Formyl-4-(2-Chloro-5-carbomethoxyphenyl)semicarbazide
To a solution of 2-chloro-5-phenoxycarbonylamino-benzoic acid methyl ester (0.22 g, 0.72 mmol) in dimethyl sulfoxide (1.4 mL) was added formic hydrazide (0.135 g, 3.15 mmol). After stirring at room temperature for 20 hours, the reaction mixture was partitioned between ethyl acetate and 1.0 N HCl. The organic phase was washed with brine, dried and concentrated in vacuo. The residue was purified on silica gel (30% methanol in ethyl acetate) to yield 0.03 g (17%) of a colorless solid: Mass Spectrum: (M+H ) 3:1 ratio of 272 and 274.
C: 2-Chloro-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid
A solution of 1-formyl-4-(2-chloro-5-carbomethoxyphenyl)semicarbazide (0.03 g, 0.11 mmol) in 1.0 M KOH in methanol (MeOH) (0.44 mL) was heated at 80° C. for 72 hours and cooled to room temperature. 1.0 N HCl (0.8 mL) was added and the mixture evaporated to dryness in vacuo. The residue was taken up in MeOH (1.5 mL) and filtered. The filtrate was concentrated in vacuo to yield 0.028 g (100%) of the title intermediate as an amorphous solid. Mass Spectrum (M−H): 3:1 ratio of 238 and 240.
D: 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide
To a solution of 2-chloro-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid (0.028 g, 0.117 mmol) in anhydrous dimethyl formamide (DMF) (4 mL) was added 1-hydroxybenzotriazole (0.018 g, 0.14 mmol). After stirring at room temperature for 10 minutes, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (0.025 g, 0.13 mmol) was added. After stirring at room temperature for 30 minutes, 2-chlorophenethylamine (0.018 g, 0.12 mmol) and triethylamine (0.012 g, 0.12 mmol) were added and the mixture stirred at room temperature overnight. The reaction mixture was diluted with EtOAc, washed sequentially with water and brine, and dried over sodium sulfate. Removal of solvent in vacuo followed by purification by reverse phase HPLC yielded 0.042 g (10%) of the title compound as a colorless solid. 1 H NMR (300 MHz, CDCl 3 ) δ (m, 2H), 3.45 (m, 2H), 7.25 (m, 2H), 7.35 (m, 2H), 7.60 (d, J=7.9 Hz, 1H), 7.76 (s, 1H), 7.78 (s, 1H), 8.43 (s, 1H) and 8.64 (m, 1H). Mass Spectrum (M−H) 3:1 Ratio of 375 and 377. | The present invention relates to novel to P2X 7 inhibitors of formula I
and to processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them, and their use in therapy. The active compounds of the present invention are potent inhibitors of P2X 7 and as such are useful in the treatment of inflammation, osteoarthritis, rheumatoid arthritis, cancer, reperfusion or ischemia in stroke or heart attack, autoimmune diseases and other disorders. | 2 |
RELATED APPLICATIONS
[0001] This application is a divisional application to U.S. application Ser. No. 15/197,919 filed Jun. 30, 2016 which in turn claims priority to U.S. Provisional Application 62/275,921 filed Jan. 7, 2016, all incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] A. Field of Invention
[0003] This invention pertains to a modular system that can be assembled to form multi-level lights of various sizes, shapes and configurations and the components of this system. The main elements are canopies supporting the system, hangers, power bars, and pendants, preferably including light engines driving LED bulbs. More particularly, the present invention pertains to a support for a plurality of pendants arranged in a cluster that may be used in the modular lighting system.
[0004] B. Description of the Prior Art
[0005] Designing lighting for a space has always been an interesting challenge because the lighting equipment has to meet utilitarian, technical and esthetic needs. Thus, any such endeavor is successful only if combining technical, architectural and artistic skills.
[0006] Several different types of ceiling lights are presently available, including surface mounted lights, recessed lights and hanging lights disposed on tracks either attached to the ceiling or suspended below the ceiling. The first two light categories are very conventional and are disadvantageous because the positions of the lights are fixed and the configurations available for each light are very limited. Conventional track lighting provides a little more flexibility especially as far as the positions of the lights are concerned. However, because of power requirements and other factors, the number, size and shape of light fixtures that can be used in such systems is fairly limited.
[0007] In some instances it is advantageous to have a plurality of pendants grouped together for esthetic purposes and/or to provide more light for a particular space. However conventional track systems could accommodate such clusters only if they were factory assembled. It would be very helpful to have a support for a light cluster that could accommodate several pendants and that could be assembled in the field.
SUMMARY OF THE INVENTION
[0008] Briefly, a modular lighting system for providing light in a space includes canopies connectable to a power source; a plurality of horizontal bars; a plurality of hangers, including a first set of hangers supporting bars from said canopy and a second set of hangers, each said hangers including a first end disposed between and engaging said bar segment. The system further includes a plurality of pendants supported by the second set of hangers from the bars. The hangers and bars cooperate to provide electric power to said pendants from said canopy.
[0009] Preferably, each bar includes two bar segments facing each other and being made of a non-conductive material. Conductive rails are provided on the inner surface of each bar segment. The hangers include a base configured to form an interference fit with the bar segments. In one embodiment, the hangers are made of conductive rods or cables that are in electrical contact with the rails through the respective bases.
[0010] Preferably, at least one of the canopies is connected to a line voltage and transformer is used to step down the line voltage to a lower voltage such as 24 vac which is then distributed to the pendants through the hangers and bars.
[0011] The pendants include light emitting elements such as LEDs, electronic circuitry for driving the LEDs, and are preferably shaped for heat dissipation. Since the LEDs have a long life, they are not replaceable but instead the whole pendant is replaced as needed.
[0012] In one embodiment, a cluster of pendants is provided. Preferably, the cluster is hung from the bars described above. The cluster includes a plurality of pendants and a distributor. The pendants may be identical or may be different and all include a pendant body and a pair or rods extending in parallel away from the body and having free rod ends. The distributor is formed with a plurality of sockets. One socket is used to connect the distributor to a power supply such as a hanger connected to a power bar. The remaining sockets include holes for receiving the rod ends from the pendants. The sockets are used to engage and support the pendants as well as to provide power to the same. The rod ends are selectively inserted into the sockets and secured by set screws.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows an isometric view a modular lighting system constructed in accordance with this invention with two parallel bars suspended from a single canopy;
[0014] FIG. 2 shows an isometric view of another embodiment with bars disposed at an angle with each other in a single tier and suspended from a single canopy;
[0015] FIG. 3 shows an isometric view of another embodiment of the invention in which six bars disposed at various tiers and angles are suspended from a single canopy;
[0016] FIG. 4 shows an isometric view of another embodiment of the invention in which several different bars are disposed at right angle and are supported by a canopy and other ceiling supports;
[0017] FIG. 5 shows an isometric view another embodiment of the invention in which two circular bars are disposed at different tiers and supported by a single canopy;
[0018] FIG. 6 shows another embodiment of the invention in which a single bar disposed at a right angle with respect to wall and supported by a wall-mounted canopy;
[0019] FIGS. 7A-7K show an isometric and a cross-sectional view of a bar used in the embodiments of FIGS. 1-6 ;
[0020] FIG. 7L shows an isometric view of a connector used to connect three bars in the embodiments of FIGS. 2 and 3 ;
[0021] FIGS. 8A-8E show details of a canopy used in the embodiments of FIGS. 1-6 ;
[0022] FIG. 9A-9J show details of a bar hanger used for interconnecting two bars in the embodiments of FIGS. 1-6 ;
[0023] FIG. 10 shows a front view of a hanger used for connecting a bar to a pendant or a canopy in the embodiments of FIGS. 1-6 ;
[0024] FIG. 11 shows an isometric view of a hanger with a single rod for the embodiment of FIG. 4 ;
[0025] FIGS. 12A-12C show views of a non-conductive hanger with a single rod for the embodiment of FIG. 4 ;
[0026] FIGS. 13A-13C show a top, front and isometric view of a pendant cluster used in the embodiment of FIG. 1 ;
[0027] FIGS. 14A-14P show details of a bayonet-type hanger and a pendant that is mounted using a twisting of the hanger and is used in the embodiment of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention pertains to a modular lighting system having a plurality of interchangeable elements that can be combined in many different ways to obtain a large variety of configurations. FIGS. 1-6 show four such systems identified respectively as 10 A, 10 B, 10 C, 10 D, 10 E and 10 F. Generally speaking, each system includes one or more canopies 100 , a plurality of hangers 200 , a plurality of power bars 300 and a plurality of pendants 400 . In addition, some systems may also include optional connectors 500 . Unless otherwise noted, all the hangers and all power bars consist of two elements that have dual functions, they support the pendants 400 and they provide power to the pendants, with one elements forming the positive or hot power connection and the other element defining the negative or ground power connection.
[0029] For example, system 10 in the FIG. 1 , system 10 A includes a canopy 100 that supports the system from a ceiling or other similar architectural member in a conventional manner. In this case, the canopy also provides power to the system. Canopy 100 includes a conventional power supply connected to standard AC lines for providing power to the LED tubes in the pendants as discussed below. The power supply is hidden within the canopy.
[0030] Two hangers 202 , 204 extend downwardly from the canopy. In one embodiment, each hanger discussed hereinafter consists of two solid bars or rods. These hangers are termed the power feed hangers. In an alternate embodiment the hangers are replaced by multi-strand twisted cables. As explained above, each hanger is formed of two elements (e.g., rods or cables). Preferably only two of the four elements (e.g., the rods of hanger 202 ) carry power and the other two elements are used for support.
[0031] The hangers 202 , 204 are used to support a power bar 302 . Two hangers 206 , 208 are used to support a second power bar 304 and are termed bar hangers.
[0032] Another set of hangers 210 - 218 are used to support a plurality of pendants 402 - 410 . These hangers are termed pendant hangers. The pendants 402 - 410 preferably include LED.
[0033] Included in canopy 100 is a transformer steps down the line voltage from a standard power line to 24 VAC for the pendants 402 - 410 . The other hanger 204 may be electrically floating. The power from the hanger 202 flows through the bar segments of bar 302 , hanger 206 , bar 304 and hangers 210 - 212 to the pendants. Thus, in this embodiment, only some of the pendants carry power but all the power bars do.
[0034] FIG. 2 shows a system 10 B in which three bars 306 are connected at a common connector 308 that keeps the bars at a specific angle with respect to each other to form a Y-shaped arrangement. This angle could be 120°, 45°, 135°, etc. and the bars may but need not be disposed at a constant angle between each other. Bars 306 are supported by respective hangers 202 , 204 , 206 from the canopy 102 as shown. The pendants and hangers supporting them have been omitted in this figure for the sake of simplicity.
[0035] FIG. 3 shows a system 100 with pendants arranged at several levels and extending in different directions from a central point below the canopy 102 . This is achieved by starting with a Y-shaped bar arrangement of FIG. 2 formed again of three bars 306 supported by hangers 202 , 204 , 206 and joined by a connector 308 . However, in this case, each bar 306 is used to support another bar 310 , each bar 310 being supported by a pair of hangers 208 , 210 . Hanging from each bar 310 are a plurality of pendants 410 supported by hangers 212 . All of pendants 410 supported by the same bar 310 can be disposed at different height, or different hangers may be disposed at different heights.
[0036] FIG. 4 shows yet another system 10 D. This system 10 D includes a canopy 104 with a transformer 106 . Attached to the canopy 104 is a first bar 302 A using two hangers 214 . As opposed to the hangers discussed previously, hangers 214 have a single extended element, such as bar, as described in more detail later. Each of the hangers 214 provides power to one of the elements of bar 302 A. However because the bar 302 A is not centered below the canopy 104 but extends in one direction away therefrom, another hanger 216 , which may be referred to as a ceiling hanger, is used to support a distal end 314 of bar 302 . At its top, hanger 216 is attached to a sleeve 106 secured to the ceiling in a conventional manner.
[0037] Hangers 218 are used to attach respective pendants 402 from bus 302 . Another hanger 220 is used to support a cluster of pendants 410 .
[0038] A second bar 304 A is also provided. This bar 304 A is supported at one end by a hanger 222 from bar 302 A. This hanger 222 also provides power to bar 304 A. A third bar 306 is also provided that is supported from the ceiling by ceiling hangers 216 (only one such ceiling hanger is being shown for the sake of clarity). Bar 306 supports the second end of bar 304 A and receives power from said bus 304 through hanger 224 . Each of the bars 302 A, 304 A, 306 can be used to hang pendants of various sizes and shapes and arranged in different configurations as desired.
[0039] FIG. 5 shows another system 10 E having a canopy 100 E supporting two ring-shaped, rather than rectilinear bars 330 , 332 arranged at two levels and with various shapes and types of pendants 420 extending downwardly from the respective bars 330 , 332 , each being supported and powered by a respective hanger 218 . Since the diameters of the ring-shaped bars 330 , 332 are larger than the diameter of the canopy 100 E, rods or cables 221 .
[0040] FIG. 6 shows a wall-mounted system 10 F with a wall mounted canopy 112 . A horizontal bar 321 attached directly to and extending away from the canopy 112 provides power and supports a pendant 402 via a hanger 221 . Alternately, other horizontal bars may be supported from bar 321 for hanging various pendants (not shown).
[0041] Details of a generic bar 300 are shown in FIGS. 7A-7K . Unless otherwise noted, all the bars discussed here have the same configuration. In this Figure, bar 300 is shown as being straight however, it can be circular ellipsoid or can have other geometric shape. The bar 300 includes two identical longitudinal segments 352 , 354 facing each other. A cross-sectional view of segment 354 is seen in FIG. 7B . Segment 354 is formed of a C-shaped main body 355 made of a non-conductive material, such as a plastic material that is light weight but strong so that it can support various pendants, other bars, etc. Imbedded in this main body 355 is a rail 356 made of a light weight conductive material such as aluminum. Preferably rail 356 is formed with a rectangular channel 360 . The two segments 352 , 354 are joined together at the two ends by end connectors 362 . The connectors 362 are attached to the bars by conventional means, such as screws 364 , by an adhesive or other means.
[0042] Preferably, the two segments 352 , 354 have inner surfaces spaced at a nominal distance d throughout the length of the bar 300 . The bar 300 is made in standard lengths ranging from to 12 to 48 inches. For very long bars, for example in excess of 24 inches, a spacer 366 is placed between the segments. The spacer 366 may be held in place by screws or other means.
[0043] FIG. 7C shows details of a connector 370 used to connect three bars, for example for the systems of FIGS. 2 and 3 . The connector 370 is formed of three arms 372 disposed at an angle of 120 degrees. The inner surfaces of the arms 372 are provided with rails 374 having the size and shape to fit into the channels of the rails of bars 300 . Three bars having the same, or different length are attached telescopically to the connector 370 .
[0044] Details of a typical canopy 100 are shown in FIGS. 8A-8C . Each canopy 100 includes a cup-shaped housing 120 that can be cylindrical, square, rectangular, etc. The housing 120 holds a transformer 122 receiving power from line wires 124 and outputting power at a lower voltage on output wires 126 . The output wires 126 are connected to a terminal strip 127 used to distributed the low ac voltage power through a plurality of lines 129 . As will be discussed in more detail below, preferably transformer 122 outputs power at about 24 vac. On its bottom surface 128 , the housing 120 is provided with a plurality of ferrules 130 . Depending on the exact required configuration, these ferrules 130 may be arranged single or in pairs, and a canopy may be provided with two four, six, eight ferrules, etc. Some of the ferrules provide power to the respective hangers or cables and also provide structural support. Other ferrules do not provide power but merely provide structural support.
[0045] As shown in FIGS. 8C and 8E , each conducting ferrule 130 terminates in a threaded bolt 132 . An eyelet 134 is attached to each bolt 132 using a threaded nut 133 or other conventional means. Each eyelet is connected to one of the output wires 129 .
[0046] As seen in FIGS. 8C, 8D and 8E , each ferule 130 further includes cylindrical sleeve 140 with a ferule body 147 attached to bolt 132 and extending through the housing 120 and below surface 128 . The sleeve 140 is electrically insulated from the housing 120 and receives the conductive end of a rod 142 forming a part of a hanger as described below or a cable. A set screw 144 is used to secure the rod 142 in the sleeve 140 . A washer 139 is disposed below nut 133 and is insulated from the housing 120 by an insulating disc 143 . A second insulating disc 145 is disposed above the ferule body 147 to insulate it from the housing 120 as well. The rod 142 is preferably covered with an insulator 149 .
[0047] The non-conductive ferrules have a similar configuration but are not connected to any output wires 126 . The ferrules receive rods similar to rod 142 but these latter rods do not provide power.
[0048] There are several different types of bar hangers are provided: hangers for supporting bars from canopies, hangers for supporting bars from ceilings (without a power connection), hangers for supporting one bar from another bar and hangers for supporting pendants. All these hangers have must be able to interface with a bar at least at one end as described below.
[0049] There are two types bar-to-bar hangers: parallel hangers for connecting two parallel bars and perpendicular hangers connecting two bars running perpendicular two each other.
[0050] FIGS. 9A-9G show details of parallel bar hanger such as hanger 206 supporting bar 304 from bar 302 in FIG. 1 . The hanger 206 includes two vertical segments 230 A, 230 B. At the top and the bottom, the two segments 230 A, 230 B have their ends imbedded in identical W-shaped bases 232 , shown in more detail in FIGS. 9B-9E . The base 232 forms two channels 234 , 236 with a wall 238 separating the two channels. The base 232 is further formed with two metallic springs or clips 240 , 242 . Clip 240 is electrically attached to segment 230 A within the base 232 , and clip 242 is connected to segment 230 B. Preferably, base 232 is made of a non-conductive material and is overmolded to cover portions of the clips 240 , 242 and segments 230 A, 230 B. In one embodiment, the two bases 232 have a single, unitary structure. In another embodiment, at least the top base is made of two sections 232 A, 232 B that snap together along line 232 forming an interference fit therebetween.
[0051] As can be seen in FIGS. 9F and 9G , the bases 232 as sized and shaped so that they fit over and engage the bars 302 , 304 . Importantly, the clips 240 , 242 are sized and shaped so that they engage the rails 356 , 358 . The clips 240 , 242 have a flat section 244 sized and shaped to snap into the channels 356 , 358 of the bars 302 , 304 . In this manner not only do the clips 240 , 242 provide a solid electrical contact with the rails 356 , 358 but they also stabilize the hangers on the bars and insure that the lower bar 304 remains stiff and does move around in use. The clips may be made from beryllium copper.
[0052] Hanger 208 has a similar configuration however the clips need not be connected electrically to the hanger segments. In other cases, for example, in the configuration shown in FIG. 4 , hangers 222 do provide electrical connection to bars 304 A and 306 .
[0053] The hanger segments 230 A, 230 B are provided in various lengths as required to obtain the various systems described above, and they are preferably made in the shape of rods of a stiff but somewhat springy material having shape memory such as a phosphor/bronze alloy. Preferably except where an electrical contact is required, the rods are covered or painted with with a thin electrically insulating material.
[0054] The hangers can be installed by separating the two segments 230 A, 230 B, passing the ends of the respective bars 302 , 304 . . . between the segments, then lowering or raising the bars toward the respective bases 232 and then snapping the bases onto the bars into the configurations shown in FIGS. 9F and 9G .
[0055] As discussed above, and illustrated in more detail below, in some instances, the power bars extend perpendicularly to each other. For example, in FIG. 4 , bars 302 and 304 are perpendicular to each other. These bars are interconnected using a hanger 222 shown in FIGS. 9H-9J . This hanger 222 has two segments 272 A, 272 B and a base 232 similar to the base 232 in FIGS. 9A-9G . However, at the bottom hanger 222 is provided with a different base 274 . This base 274 is formed with two side wings 274 A, 274 B and a center wall 274 C. Clips 276 , 278 are provided on the center wall 274 C and are connected electrically with segments 272 A, 272 B, respectively as show in FIG. 9J . The center wall 274 C is made with two holes 280 A, 280 B with the lower ends of segments 272 A, 272 B extending into the holes and being secured to the base 222 . The base 270 is sized and shaped to engage and support the power bar segments 304 A, 304 B of a bar 304 A with the segments 272 A, 272 B providing power to these power bar segments. The base 232 engages the segments of the bar 302 in the manner discussed above.
[0056] In addition to the bar hangers, other types of hangers are used in the system as well. FIG. 10 shows a side view of a hanger having a base 232 and two segments 252 A, 252 B. The difference between this hanger and the hanger in FIG. 9A is that the ends of segments 252 A, 252 B are straight bare ends of the conductive rods. This bare ends are then inserted into the ferrules 130 as shown in FIG. 8D . (Of course, for this use, the hanger is turned upside down). Alternatively, the hanger is used a pendant cluster such as cluster 410 in FIG. 4 or other pendants.
[0057] FIG. 11 shows a single rod hanger 214 . This hanger 214 includes a base 274 A similar to base 274 shown in FIGS. 9H, 9J . The base 274 A has two clips 276 , 278 . When the base 274 is mounted on a bar (such as bar 302 A), the clips 276 , 278 engage the rail within the bar 302 A as discussed above. However only one of the clips (say clip 276 ) is connected to rod 272 C. The free end 272 D of the rod 272 C is attached to the ferrule of a canopy. Two such hangers 214 are used to support bar 302 A (as seen in FIG. 4 ), with each of the hangers feeding power to one of the rails of the bar.
[0058] FIG. 12A-12C show a nonconductive hanger 216 used for supporting a bar, such as bar 304 A in FIG. 4 from a ceiling. This hanger 216 provides only support and therefore it can have an elongated member 272 D which may but need not be identical to the rod 272 C in FIG. 11 . The member 272 D ends in a base 274 B that is similar to the base 274 but need not have any clips since there is no need to connect to the rails of the bus 304 A. Since there are no clips provided for the base 274 B, a cover 274 C is attached to the body 274 D of the base 274 B to insure that the bar does not slip out. The cover 274 C is attached to the body 274 D by screws 274 E or other conventional means. The other end of the elongated member 272 D is attached to a sleeve 277 via a set screw 277 A. Preferably, the ferrule 277 is similar to the ferrules of the canopy 100 in that it has a similar sleeve for capturing the end of the member 272 D. A small screw (not shown) is used as an attachment means. A large screw 279 or other conventional means may be used to attach the sleeve 277 directly to the ceiling or other architectural surface. Alternatively, the screw 279 is attached to a mounting post 281 and an anchor 283 ( FIG. 12C ).
[0059] FIGS. 13A-13C show a top, plan and isometric view of lamp cluster 410 . The cluster 410 includes a distributor 430 , and three pairs of connectors 432 connecting the distributor 430 to three pendants 402 A, 402 B, 402 C. The pendants can have the same or different shapes. Importantly, the distributor has to top holes 434 , 436 . The ends of the rods shown in FIG. 9 are inserted into the holes 434 , 436 and then set screws on the sides of the distributor, such as at 438 are tightened thereby attaching and mechanically securing the pendant cluster 410 to the hanger. The hanger and the cluster can now be hanged from a bar 300 .
[0060] Other structures may be used for attaching pendants to the hangers. One such structure is shown in FIGS. 14A-140 . FIG. 14A shows an orthogonal view of hanger 210 being inserted into pendant 402 . As shown in FIGS. 14A, 14B 14 C and 14 D, the hanger 210 includes two vertical segments 602 A, 602 B joined by standard base 232 . The segment 602 A is terminated at the bottom with a connecting spade 604 that has a generally flat, rectangular cross section (as seen in FIG. 14D ) of thickness t 1 . Spade 604 includes a narrow shank 606 having a height h 1 and a generally square tip having a width w 1 . Segment 602 B has the same shape as segment 602 A and the two spades 604 are normally aligned in parallel to each other and perpendicular to the plane formed by the two parallel segments 602 A, 602 B, as seen in FIG. 14A .
[0061] Pendant 410 is formed with an upper and a lower section 610 , 612 (see FIG. 14L ). The upper section 610 contains a light engine (not shown) that is powered by the 24 vac source provided by the segments 602 A, 602 B and generates appropriate power to light generators (such as LEDs—not shown) disposed in the lower section 612 . The walls of the lower section are translucent or transparent to allow the light from the light sources to be projected outwardly and provide space illumination. Various pendants may have sections of different shapes and sizes. In one embodiment, the upper section 610 includes a cavity 620 with two holes 622 , 624 .
[0062] The cavity 620 holds two contacts 630 , 640 (see FIGS. 14E, 14F ). Each contact is connected to the light engine (not shown). Contact 630 is formed with two facing blades having flat portions 632 , 634 . The distance between the blade portions 632 , 634 is t 2 which is preferably equal or slightly larger than t 1 but smaller than w. Contact 640 has two similar blades with flat portions 642 , 644 . The blade portions 632 , 634 , 642 , 644 have a height h 2 that is slightly smaller than height h 1 .
[0063] The pendant 410 is attached to the hanger 210 as follows. First, the hanger 210 is positioned on top of pendant 410 with the tips of spades 604 inserted into holes 622 , 624 as seen in FIG. 14A, 14G . In this orientation, the spades 604 come into contact with the top pf respective blades 630 , 640 , as shown in FIG. 14H and stop because they can go no further.
[0064] Next, the pendant 610 and top of the hanger 210 is rotated in direction A by a quarter turn (90 degrees). This rotation causes the spades 604 to turn by the same angle so that they are now in parallel with the blade sections 632 , 634 , or 642 , 644 respectively, as seen in FIGS. 14I and 14J . At this point, the hanger 210 can be and is pushed further downward so that the spades 604 enter into cavity 620 between the blades. This motion downward can continue until the tips 608 pass the blade sections 632 , 634 , 642 , 644 ( FIG. 14K ).
[0065] Now the hanger 210 is released and the spring action of the two segments 602 A, 602 B cause the top of the hanger 210 to rotate back in direction B ( FIG. 14L ) toward its natural or rest configuration. This action causes the spades 604 to rotate as well. As this action is completed, the tips 608 become trapped under the blade sections (see FIGS. 14M-140 ). In this manner the hanger 210 and pendant 410 become interlocked. The hanger 210 and pendant 410 can be attached to any bus 300 as required. If necessary, the pendant 410 can be separated from the hanger 210 by twisting it by a quarter turn and reversing the sequence discussed above.
[0066] As discussed above, and illustrated in the drawings, the various components or elements described above can be combined into numerous different kinds of configurations. The figures show some systems that include several subsystems that are attached so that they can be extend in three dimensions, to create a linear or circular configurations, or combinations thereof. Moreover, while the systems discussed above are all suspended from a ceiling, other systems are shown and described (together with any special components, if any) that are attached to vertical walls—e.g. sconce-type systems.
[0067] Electrically, all these systems have one or more canopies, buses, and hangers that provide a power supply for the canopies. As discussed above, preferably power within the system is distributed at 24 vac to the individual pendants. Light engines within the pendants the use this source to generate light via LEDs or other similar efficient, long life light elements. The systems do not use any conventional bulbs that need replacement. It is presently estimated that the linear distance between a canopy and the furthest pendant can be up to about 30 feet. For larger systems, it is advisable to use two or more canopies. As indicated above, for two or more source-systems, the bars can be interconnected mechanically but isolated electrically as needed. As discussed above, in conjunction with FIG. 3 , one bar of a system, for example bar 306 can have two sections 306 A, 306 B that are electrically insulated from each other with the rails of each section being fed and electrically connected to a different canopy 100 .
[0068] In this manner, the modular presented herein can be used to make systems having different configurations. Because the hangers can be attached easily in the field to the canopies, the bars and the pendants, each system can be assembled very quickly and efficiently using the various components described above. Moreover, many different kinds of pendants can be used with the system. As long as each pendant is capable of being connected to any of the hangers described above, it can be incorporated into a system without any changes to any of its other components.
[0069] Obviously numerous modifications may be made to the invention without departing from its scope as defined in the appended claims. | A plurality of lighting pendants and a distributor are arranged in a cluster and hung vertically. The distributor includes a plurality of sockets, one socket being connected to a hanger for receiving power and the remaining sockets being connected to the pendants to support the pendants and to provide power thereto. The pendants include parallel rods terminating in rod ends that slide into the respective sockets and then are attached to the distributor using set screws. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a double-cylinder pump especially for the conveying of cement from an input feed container with two openings each leading to a respective one of two conveying cylinders, in front of which openings one end of a driven distribution pipe is pivotable, said one end being sealed with the aid of a fixed spectacles-shaped plate and an axially arranged, preferably adjustable, wearing ring.
With pumps of this kind which are used generally for the conveying of viscous porridge-like masses, in practice mainly cement, the cement which is to be conveyed flows into one conveyor cylinder from the input feed container whilst the other conveyor cylinder which has been filled by the previous stroke, delivers its contents through the distribution pipe into a conveyor conduit connected to the input feed container.
The drive serves for delivering the necessary movement energy for the swivelling movement of the distribution pipe corresponding to the respective strokes of the pump. The end of the distribution pipe nearer to the conveyor cylinder must be sealed so that on pressure strokes of the conveyor cylinder, leakage, particularly of liquid and fine grained components of the conveyed medium, between the cylinder opening and the distribution pipe is prevented. With the conveying of cement, there exists the danger that such leakage could cause weakening of the cement mix. On the one hand, the seal must withstand the pressures which result from the considerable conveying heights over which modern cement pumps must operate. On the other hand the seal must permit the assimilation of the wear which occurs between the movable and fixed parts of the seal.
It is known to install the wearing ring in a spectacles-shaped plate (i.e. a plate containing two apertures side by side) for each conveyor cylinder opening, and to install the shaft of the distribution pipe drive so that it can be adjusted axially, thereby allowing the end of the distribution pipe on the side of the conveyor cylinder to be displaced to assimilate the wear between the wearing ring and the openings of the spectacles-shaped plate in the preliminary feed container U.S. Pat. No. 3,726,614. Whilst, in this known device, the shaft of the distribution pipe drive can be adjusted with a screwed-on nut, there can, with a further, also previously known, device of this kind, also be provided an additional pressure screw which acts between the distribution pipe and a swivel lever connected to the shaft (German Offenlegungsschrift No. 2362670).
It is furthermore known, to mount the wearing ring so that it is slightly displaceable axially on the end of the distribution pipe nearer to the conveyor cylinder and to leave a groove between the end of the distribution pipe and the ring, in which groove the hydrostatic pressure of the conveyed medium acts on the one face, on one side of the ring, and on the other face on, the end side of the distribution pipe. By this, the distribution ring should be automatically pressed on to the spectacles-shaped plate, and thus be adjusted in accordance with the wear with the aid of the hydrostatic pressure. (Zeitschrift Baumaschinendienst, issue May 5, 1976, page 234).
Practical experience with seals of this kind shows that cement pumps thus installed do not function satisfactorily. On the one hand, the wear is uneven in so far as the path lengths traversed by the different paths during swivelling of the distribution pipe differ appreciably from each other. For this reason, increased wear occurs with increases in the distance from the pivot shaft. This uneven wear occurs after a relatively short time of operation because the distance between the pivot axis and the cylinder openings is kept as small as possible. The wear can however not be completely assimilated by axial adjustment of the wearing ring. Apart from this, the distributor pipe is pivoted out of the plane of the spectacles-shaped plate by the hydrostatic pressure of the conveyor medium because of the elastic deformation of the body of the pipe, and/or because of the necessary play in the mounting of the distribution pipe. In this manner a gap occurs which is largest in the areas furthest, removed from the pivoting shaft of the drive. If however the task of pressing the wearing ring is left to the hydrostatic pressure alone, then the wearing ring can, when operating against a low conveying resistance, be moved away from the spectacles-shaped plate by the entry of sand or foreign bodies between the two elements, which effect can lead to jamming of the distribution pipe.
The essential task of the invention is to form the seal at the end of the distribution pipe nearer to the conveyor cylinder in such a manner that deterioration of the seal owing to the influence of distortion and displacement because of the hydrostatic pressure can not occur. In a preferred embodiment of the invention uneven wear can be compensated in a pump which has a relatively short distance between the pivot shaft and the cylinder openings.
According to the invention this task is resolved in that the wearing ring is located on a clamping or pressing device and the pipe end and the wearing ring are arranged to be movable with respect to each other and sealed off against each other.
Thus the invention provides a double-cylinder pump, comprising an input container with two openings, two conveyor cylinders each in communication with a respective one of said openings, a driven distribution pipe with one end pivotally movable between the two openings which end is sealed with the aid of a fixed spectacles-shaped plate surrounding said openings an axially arranged wearing ring for sealing said pipe end to the spectacles-shaped plate and a clamping device on which the wearing ring is positioned, the end of the distribution pipe and the wearing ring being arranged to be movable with respect to each other and sealed off one against the other.
For preference, the clamping device is coupled to a drive for the pivotal movement of the distribution pipe and furthermore the wearing ring for its part is located so that it can be pivoted.
In that the wearing ring is connected to a clamping device not influenced by the distribution pipe, and that the end of the distribution pipe nearer to the conveyor cylinder is sealed so as to be movable relative to the wearing ring, the condition is created that unavoidable movements of the distribution pipe and the action of the conveying pressure have no unfavourable influence on the tightness of the metallic seal between cylinder openings and the wearing ring. On the other hand, the movable locating of the end of the distribution pipe in the wearing ring permits pivotal movement of the wearing ring with respect to the end of the pipe which, for its part, permits the seating of the wearing ring on the spectacles-shaped plate, even after uneven wear, for example by the known axial displacement, of the pivot shaft. Under these conditions, the wearing ring engages with the spectacles-shaped plate over its entire periphery because the wearing ring correspondingly pivots and, by this, makes possible an overall assimilation of varying wear. The sealing of the end of the pipe to wearing ring does not present a problem. The advantages which can be achieved by the invention lie principally in that, with considerable conveying heights, and correspondingly high pressures, absolutely tight connections of the distribution pipe to the cylinder openings can be attained and that if need be, by using known auxiliary arrangements, the varying wear can be compensated and the appearance of additional spaces in the sealing, which can lead to lack of tightness, can be prevented.
Preferably, pivot pins are used for the pivotable positioning of the wearing ring through which pivot pins runs the pivot axis of the wearing ring. According to an embodiment of the invention the pivot pins are located directly on a lever, which forms part of the distributor pipe drive. In another embodiment of the invention bearings are used which consist of convex and concave segments.
In a further embodiment of the invention a frame is provided which is adjustably mounted with respect to the spectacles-shaped plate, and which serves for the guiding of the moving part of the seal. The end of the pipe can be movably positioned and sealed in the wearing ring and/or a guide ring can be connected to the wearing ring. Other embodiments of the invention provide for the positioning and sealing of the wearing ring in the end of the pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
Details, further characteristics and other advantages of the invention will be apparent from the following description of several embodiments thereof, with reference to the accompanying drawings, in which:
FIG. 1 is a longitudinal section of a preferred embodiment of the invention shown in part representation,
FIG. 2 is an end view of the embodiment according to FIG. 1 partly in cross-section,
FIG. 3 shows the seal of the embodiment shown in FIGS. 1 and 2 after it has been subject to wear,
FIG. 4 a plan view corresponding to FIG. 3, the positioning of bearings being shown partly in section,
FIG. 5 shows an embodiment of the invention with a modified form of distribution pipe,
FIG. 6 shows an embodiment of the invention with a further modified distribution pipe,
FIG. 7 shows a modified embodiment of the invention in which a frame is used for the pressing of the wearing ring, shown in section,
FIG. 8 is an end view, corresponding to FIG. 2, of the embodiment shown in FIG. 7,
FIG. 9 shows a modified embodiment of the object of the invention in a view corresponding to FIG. 3,
FIG. 10 shows a modification of the embodiment of FIG. 9,
FIG. 11 shows a modified embodiment of the invention in a view corresponding to FIG. 3,
FIG. 12 shows a further modified embodiment of the invention in a view corresponding to FIG. 3, and
FIG. 13 shows a further embodiment of the invention with the means for positioning of the wearing ring modified as compared to FIG. 5.
In the various illustrated embodiments, the same reference numbers refer to the corresponding parts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 and 2 part of one of two conveyor cylinders 1 is shown in section. In the conveyor cylinder 1, a piston 2 moves with a piston rod 3 in such a manner that, on the retraction of the piston 2 cement is sucked from an input container 4, and, on the piston moving forward, the cement can be pressed out of the cylinder 1. The input container has two openings 5 and 6, each corresponding to a respective cylinder as can be seen from FIG. 2. The input container has, in the embodiment illustrated, a filling funnel 7 and an opening which can be closed with a lid 8 at its lowest part. The two openings 5 and 6 are alternatively connected to the end of a pipe 9, located outside the input container 4, through which pipe the cement sucked from the conveyor cylinder is conveyed.
The necessary distribution of the cement for this purpose is effected by means of an S-shaped distribution pipe 10, one end 11 of which is pivotally connected and sealed to the conduit 9. For this purpose the end 11 is welded to a hollow cylinder 12, which is fitted into a sleeve 14 screwed to an outer part 13 and supported therein by a ring 14a. Furthermore a seal 15 is provided between the cylinder 12 and the sleeve 14. The end of the pipe 9 is fastened in position by a sleeve 16 and a correspondingly formed seal 17. A hollow body 22 is welded to the end of the distributor pipe 10 nearer to the cylinders. The hollow body 22 has two cams 18 and 19 respectively, off-set at 180°, which, together with slots 20 and/or 21 in a guide ring 23, provide for movable positioning of the end of the pipe 22. Furthermore, the end of the pipe 22 is sealed off in the guide ring 23 by means of a sealing ring 24.
The one side of the guide ring 23 carries a wearing ring 26 which is supported, on the one side, on said side of the guide ring 23 and, on the other side, on a spectacles-shaped plate 27. Because the guide ring 23 is provided with two pivot pins 28 and 29 off-set with respect to each other by 180°, the wearing ring 26 can also pivot so that it, can align itself with the surface of the spectacles-shaped plate 27 independently of the amount of wear over its surface. For this purpose, the pivot pins 28 and 29 are located in respective pivot bearings 30 and 31 of a fork-shaped lever 32 which is fastened by a lug to the end of a pivot shaft 33 within the input container 4. The pivot shaft 33 is connected by a spline and groove connection 34 to a drive lever 35 which is movable reciprocably by a motor 36 which is not shown in detail.
The spectacles-shaped plate 27 abuts against a reinforced wall 39 of the input container, which for its part has a respective recess for the connection of a connecting piece 40 to each conveyor cylinder. Initially, the parts assume the relative positions shown in FIGS. 1, 2 and 4. However, as soon as wear occurs, the sealing arrangement must be adjusted. In the embodiment illustrated, a nut 42, screwed on to the outer end 44 of the pivot shaft 33 serves for this purpose. On tightening the nut 42, the pivot shaft 33 moves axially, so that, by means of the pivot lever 32 and the pin positioning means 28 to 31, the guide ring 23, and with it also the wearing ring 26 are similarly moved. Because of the pin positioning means, the guide ring 23 can be swivelled together with the wearing ring 26 about a swivelling axis passing through the pins 28 and 29. Consequently the plane of the wearing ring 26 allows itself to be changed with respect to the plane of the spectacles-shaped plate 27. In this way, it is possible to assimilate the more severe wear which occurs, at the lower end of the wearing ring in the illustrated embodiment, even if, the pipe end 22 has retained its original position and/or has swivelled under the influence of the hydrostatic pressure in the opposite direction. The illustrated mechanical adjustment means, employing the nut 42, can, of course, be replaced by an automatic arrangement employing a hydraulic tightening cylinder or spring clamping elements.
In the embodiment shown in FIG. 5, the shape of the distribution pipe has been changed from an S shape to a U shape. The lower bend 45 of the distribution pipe 10 carries a support 46 for engagement with an abutment 47, which is mounted on the lower part 13 of the input container 4. In this way, the hydrostatic forces which act on the U-shaped distribution pipe 10 are balanced. The remaining parts correspond to the arrangement which are shown in FIGS. 1 to 4 and have been explained as above. The only thing that is omitted is the tightening device.
The embodiment shown in FIG. 6 differs from the embodiment according to FIGS. 1 to 4 in that, although an S-shaped distributor pipe 10 is used, it is arranged not horizontally but vertically in the input container 4. For this reason, the connecting piece 40 is bent through more than 90°.
In the embodiment shown in FIG. 7, the arrangement used for the sealing of the pipe end 22, at the conveyor cylinder side of the swivel pipe 10, differs from the embodiments shown in FIGS. 1 to 6. Here, the guide ring 23 sits in a frame 50, but again carried on its end side 51, the wearing ring 26. The apparatus illustrated in FIG. 7, has already been subject to uneven wear and the drawing corresponds to this extent to FIG. 3. As can be seen from FIG. 8, the frame 50 in the embodiment shown in FIG. 7 can be adjusted with the aid of several adjustment screws 50a to 50d to compensate for the wear with respect to the spectacles-shaped plate shown in FIG. 7. In a corresponding manner, the guide ring 23 adjusts itself to the plane of the spectacles-shaped plate, and the wearing ring 26 can follow the uneven wear. On the other hand, the distribution pipe is directly attached to the pivot shaft. A swinging positioning of the distribution pipe relative to the pivot shaft is not necessary. Tightening up takes place with the aid of the adjustment screws 50a to 50d over the frame 50.
In the embodiments shown in FIGS. 9 and 10 the arrangement of the swivel pins is modified. For this purpose, the lever 32 has a bearing which consists of concave segements 56 for respective convex cams 57 provided on the guide ring 23, the wearing ring 26 being positioned once again on the end side of the guide ring 23.
The embodiment according to FIG. 10 differs from the embodiment according to FIG. 9 in that, the wearing ring 26 is disposed within the interior of the end 22 of the swivel pipe 10 and sealed thereto by an annular seal 24a, which is supported on a hollow cylindrical extended end 58 of the wearing ring 26 and contained in a groove 59 in the inner side of the pipe end 22. This arrangement has the advantage that, as compared with the embodiment according to FIGS. 1 to 9 a smaller number of individual parts are required.
The embodiments shown in FIGS. 11 and 12 are modified with respect to the embodiments of the FIGS. 9 and 10 in that in these cases the concave segments 56 are formed on the guide ring 23 (FIG. 11) or directly on the wearing ring 26 (FIG. 12) instead of at the end of the fork prongs of the lever 32. For this reason, the cam 57 in these embodiments is on the arms of the fork of the lever 32.
The embodiment shown in FIG. 13 differs from the embodiment shown in FIG. 5 in that, the guide ring 23 in the lever 32 can no longer be swivelled but is firmly fixed. This is acceptable because of the relatively larger distance of the swivel shaft from the conveyor cylinder 1 so that the uneven wear of the wearing ring 26 is negligible with the result that it is possible in spite of omitted constructive links, to apply the wearing ring 26 to the spectacles-shaped plate 27 over its entire surface.
In all the embodiments of the invention, the pipe end 22 which provides for a positioning of the end of the pipe 10 in the guide ring 23 is bell-shaped. The sealing ring 24 is made from elastic material. | In a double-cylinder pump for conveying cement, a distribution pipe is pivotally driven into alignment with each of the cylinders in turn. A wearing ring, which provides a seal between the end of the pipe and the cylinders, is mounted so as to be movable with respect to the end of the pipe so as to be able to assimilate wear. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a (1) divisional of U.S. patent application Ser. No. 09/489,640 filed on Jan. 24, 2000 now U.S. Pat. No. 6,780,505, which itself is a (2) continuation of U.S. patent application Ser. No. 09/093,406, filed Jun. 8, 1998 now U.S. Pat. No. 6,037,032, which is itself a continuation-in-part of U.S. patent application Ser. No. 08/921,875 filed Sep. 2, 1997 now U.S. Pat. No. 6,033,506 and is a continuation-in-part of U.S. patent application Ser. No. 08/923,877 filed on Sep. 2, 1997 now abandoned, (3) which is a continuation-in-part of U.S. patent application Ser. No. 09/337,027 filed Jun. 25, 1999 now U.S. Pat. No. 6,261,485, which itself is a continuation of U.S. patent application Ser. No. 08/921,875 filed Sep. 2, 1997, now U.S. Pat. No. 6,033,506 and (4) a continuation-in-part of U.S. patent application Ser. No. 09/136,596 filed Aug. 19, 1998 now U.S. Pat. No. 6,387,343, which itself is a divisional of U.S. patent application Ser. No. 08/921,875 filed Sep. 2, 1997 now U.S. Pat. No. 6,033,506.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
The United States Government has rights in this invention pursuant to contract No. DE-AC05-960R22464 between the United States Department of Energy and Lockheed Martin Energy Research Corporation.
BACKGROUND OF THE INVENTION
The present invention relates to porous carbon foam filled with phase change materials and encased to form a heat sink product, and more particularly to a process for producing them.
There are currently many applications that require the storage of large quantities of heat for either cooling or heating an object. Typically these applications produce heat so rapidly that normal dissipation through cooling fins, natural convection, or radiation cannot dissipate the heat quickly enough and, thus, the object over heats. To alleviate this problem, a material with a large specific heat capacity, such as a heat sink, is placed in contact with the object as it heats. During the heating process, heat is transferred to the heat sink from the hot object, and as the heat sink's temperature rises, it “stores” the heat more rapidly than can be dissipated to the environment through convection. Unfortunately, as the temperature of the heat sink rises the heat flux from the hot object decreases, due to a smaller temperature difference between the two objects. Therefore, although this method of energy storage can absorb large quantities of heat in some applications, it is not sufficient for all applications
Another method of absorbing heat is through a change of phase of the material, rather than a change in temperature. Typically, the phase transformation of a material absorbs two orders of magnitude greater thermal energy than the heat capacity of the material. For example, the vaporization of 1 gram of water at 100° C. absorbs 2,439 joules of energy, whereas changing the temperature of water from 99° C. to 100° C. only absorbs 4.21 Joules of energy. In other words, raising the temperature of 579 grams of water from 99° C. to 100° C. absorbs the same amount of heat as evaporating 1 gram of water at 100° C. The same trend is found at the melting point of the material. This phenomenon has been utilized in some applications to either absorb or evolve tremendous amounts of energy in situations where heat sinks will not work.
Although a solid block of phase change material has a very large theoretical capacity to absorb heat, the process is not a rapid one because of the difficulties of heat transfer and thus it cannot be utilized in certain applications. However, the utilization of the high thermal conductivity foam will overcome the shortcomings described above. If the high conductivity foam is filled with the phase change material, the process can become very rapid. Because of the extremely high conductivity in the struts of the foam, as heat contacts the surface of the foam, it is rapidly transmitted throughout the foam to a very large surface area of the phase change material. Thus, heat is very quickly distributed throughout the phase change material, allowing it to absorb or emit thermal energy extremely quickly without changing temperature, thus keeping the driving force for heat transfer at its maximum.
Heat sinks have been utilized in the aerospace community to absorb energy in applications such as missiles and aircraft where rapid heat generation is found. A material that has a high heat of melting is encased in a graphite or metallic case, typically aluminum, and placed in contact with the object creating the heat. Since most phase change materials have a low thermal conductivity, the rate of heat transfer through the material is limited, but this is offset by the high energy absorbing capability of the phase change. As heat is transmitted through the metallic or graphite case to the phase change material, the phase change material closest to the heat source begins to melt. Since the temperature of the phase change material does not change until all the material melts, the flux from the heat source to the phase change material remains relatively constant. However, as the heat continues to melt more phase change material, more liquid is formed. Unfortunately, the liquid has a much lower thermal conductivity, thus hampering heat flow further. In fact, the overall low thermal conductivity of the solid and liquid phase change materials limits the rate of heat absorption and, thus, reduces the efficiency of the system.
Recent developments of fiber-reinforced composites, including carbon foams, have been driven by requirements for improved strength, stiffness, creep resistance, and toughness in structural engineering materials. Carbon fibers have led to significant advancements in these properties in composites of various polymeric, metal, and ceramic matrices.
However, current applications of carbon fibers have evolved from structural reinforcement to thermal management in application ranging from high-density electronic modules to communication satellites. This has stimulated research into novel reinforcements and composite processing methods. High thermal conductivity, low weight, and low coefficient of thermal expansion are the primary concerns in thermal management applications. See Shih, Wei, “Development of Carbon—Carbon Composites for Electronic Thermal Management Applications,” IDA Workshop, May 3–5, 1994, supported by A F Wright Laboratory under Contract Number F33615-93-C-2363 and A R Phillips Laboratory Contract Number F29601-93-C-0165 and Engle, G. B., “High Thermal Conductivity C/C Composites for Thermal Management,” IDA Workshop, May 3–5, 1994, supported by A F Wright Laboratory under Contract F33615-93-C-2363 and A R Phillips Laboratory Contract Number F29601-93-C-0165. Such applications are striving towards a sandwich type approach in which a low-density structural core material (i.e. honeycomb or foam) is sandwiched between a high thermal conductivity facesheet. Structural cores are limited to low density materials to ensure that the weight limits are not exceeded. Unfortunately, carbon foams and carbon honeycomb materials are the only available materials for use in high temperature applications (>1600° C.). High thermal conductivity carbon honeycomb materials are extremely expensive to manufacture compared to low conductivity honeycombs, therefore, a performance penalty is paid for low cost materials. High conductivity carbon foams are also more expensive to manufacture than low conductivity carbon foams, in part, due to the starting materials.
In order to produce high stiffness and high conductivity carbon foams, invariably, a pitch must be used as the precursor. This is because pitch is the only precursor which forms a highly aligned graphitic structure which is a requirement for high conductivity. Typical processes utilize a blowing technique to produce a foam of the pitch precursor in which the pitch is melted and passed from a high pressure region to a Low pressure region. Thermodynamically, this produces a “Flash,” thereby causing the low molecular weight compounds in the pitch to vaporize (the pitch boils), resulting in a pitch foam. See Hagar, Joseph W. and Max L. Lake, “Novel Hybrid Composites Based on Carbon Foams,” Mat. Res. Soc. Symp ., Materials Research Society, 270:29–34 (1992); Hagar, Joseph W. and Max L. Lake, “Formulation of a Mathematical Process Model Process Model for the Foaming of a Mesophase Carbon Precursor,” Mat. Res. Soc. Symp., Materials Research Society, 270:35–40 (1992); Gibson, L. J. and M. F. Ashby, Cellular Solids: Structures & Properties , Pergamon Press, New York (1988); Gibson, L. J., Mat. Sci. and Eng A110, 1 (1989); Knippenberg and B. Lersmacher, Phillips Tech. Rev., 36(4), (1976); and Bonzom, A., P. Crepaux and E. J. Moutard, U.S. Pat. No. 4,276,246, (1981). Then, the pitch foam must be oxidatively stabilized by heating in air (or oxygen) for many hours, thereby, crosslinking the structure and “stabilizing” the pitch so it does not melt during carbonization. See Hagar, Joseph W. and Max L. Lake, “Formulation of a Mathematical Process Model Process Model for the Foaming of a Mesophase Carbon Precursor, Mat. Res. Soc. Symp ., Materials Research Society, 270:35–40 (1992); and White, J. L., and P. M. Shaeffer. Carbon, 27:697 (1989). This is a time consuming step and can be an expensive step depending on the part size and equipment required. The “stabilized” or oxidized pitch is then carbonized in an inert atmosphere to temperatures as high as 1100° C. Then, graphitization is performed at temperatures as high as 3000° C. to produce a high thermal conductivity graphitic structure, resulting in a stiff and very thermally conductive foam.
Other techniques utilize a polymeric precursor, such as phenolic, urethane, or blends of these with pitch. See Hagar, Joseph W. and Max L. Lake, “Idealized Strut Geometries for Open-Celled Foams,” Mat. Res. Soc. Symp ., Materials Research Society, 270:41–46 (1992); Aubert, J. W., MRS Symposium Proceedings, 207:117–127 (1990); Cowlard, F. C. and J. C. Lewis, J. of Mat. Sci., 2:507–512 (1967); and Noda, T., Inagaki and S. Yamada, J. of Non-Crystalline Solids, 1:285–302, (1969). High pressure is applied and the sample is heated. At a specified temperature, the pressure is released, thus causing the liquid to foam as volatile compounds are released. The polymeric precursors are cured and then carbonized without a stabilization step. However, these precursors produce a “glassy” or vitreous carbon which does not exhibit graphitic structure and, thus, has low thermal conductivity and low stiffness. See Hagar, Joseph W. and Max L. Lake, “Idealized Strut Geometries for Open-Celled Foams,” Mat. Res. Soc. Symp ., Materials Research Society, 270:41–46 (1992).
In either case, once the foam is formed, it is then bonded in a separate step to the facesheet used in the composite. This can be an expensive step in the utilization of the foam.
The extraordinary mechanical properties of commercial carbon fibers are due to the unique graphitic morphology of the extruded filaments. See Edie, D. D., “Pitch and Mesophase Fibers,” in Carbon Fibers, Filaments and Composites , Figueiredo (editor), Kluwer Academic Publishers, Boston, pp. 43–72 (1990). Contemporary advanced structural composites exploit these properties by creating a disconnected network of graphitic filaments held together by an appropriate matrix. Carbon foam derived from a pitch precursor can be considered to be an interconnected network of graphitic ligaments or struts, as shown in FIG. 1 . As such interconnected networks, they represent a potential alternative as reinforcement in structural composite materials.
The process of this invention overcomes current manufacturing limitations by avoiding a “blowing” or “pressure release” technique to produce the foam. Furthermore, an oxidation stabilization step is not required, as in other methods used to produce pitch based carbon foams with a highly aligned graphitic structure. This process is less time consuming, and therefore, will be lower in cost and easier to fabricate. The foam can be produced with an integrated sheet of high thermal conductivity carbon on the surface of the foam, thereby producing a carbon foam with a smooth sheet on the surface to improve heat transfer.
SUMMARY OF THE INVENTION
An object of the present invention is production of encased high thermal conductivity porous carbon foam filled with a phase change material wherein tremendous amounts of thermal energy are stored and emitted very rapidly. The porous foam is filled with a phase change material (PCM) at a temperature close to the operating temperature of the device. As heat is added to the surface, from a heat source such as a computer chip, friction due to re-entry through the atmosphere, or radiation such as sunlight, it is transmitted rapidly and uniformly throughout the foam and then to the phase change material. As the material changes phase, it absorbs orders of magnitude more energy than non-PCM material due to transfer of the latent heat of fusion or vaporization. Conversely, the filled foam can be utilized to emit energy rapidly when placed in contact with a cold object.
Non-limiting embodiments disclosed herein are a device to rapidly thaw frozen foods or freeze thawed foods, a design to prevent overheating of satellites or store thermal energy as they experience cyclic heating during orbit, and a design to cool leading edges during hypersonic flight or re-entry from space.
Another object of the present invention is to provide carbon foam and a composite from a mesophase or isotropic pitch such as synthetic, petroleum or coal-tar based pitch. Another object is to provide a carbon foam and a composite from pitch which does not require an oxidative stabilization step.
These and other objectives are accomplished by a method of producing carbon foam heat sink wherein an appropriate mold shape is selected and preferably an appropriate mold release agent is applied to walls of the mold. Pitch is introduced to an appropriate level in the mold, and the mold is purged of air by applying a vacuum, for example. Alternatively, an inert fluid could be employed. The pitch is heated to a temperature sufficient to coalesce the pitch into a liquid which preferably is of about 50° C. to about 100° C. above the softening point of the pitch. The vacuum is released and an inert fluid applied at a static pressure up to about 1000 psi. The pitch is heated to a temperature sufficient to cause gases to evolve and foam the pitch. The pitch is further heated to a temperature sufficient to coke the pitch and the pitch is cooled to room temperature with a simultaneous and gradual release of pressure. The foam is then filled with a phase change material and encased to produce an efficient heat storage product.
In another aspect, the previously described steps are employed in a mold composed of a material such that the molten pitch does not adhere to the surface of the mold.
In yet another aspect, the objectives are accomplished by the carbon foam product produced by the methods disclosed herein including a foam product with a smooth integral facesheet.
In still another aspect a carbon foam composite product is produced by adhering facesheets to the carbon foam produced by the process of this invention.
FIG. 1 is section cut of a heat sink device for thawing food using acetic acid as the phase change material.
FIG. 2 is a section cut of a heat sink to prevent overheating of satellites during cyclic orbits.
FIG. 3 is a section cut of a heat sink used on the leading edge of a shuttle orbiter.
FIG. 4 is a micrograph illustrating typical carbon foam with interconnected carbon ligaments and open porosity.
FIG. 5–9 are micrographs of pitch-derived carbon foam graphitized at 2500° C. and at various magnifications.
FIG. 10 is a SEM micrograph of carbon foam produced by the process of this invention.
FIG. 11 is a chart illustrating cumulative intrusion volume versus pore diameter.
FIG. 12 is a chart illustrating log differential intrusion volume versus pore diameter.
FIG. 13 is a graph illustrating the temperatures at which volatiles are given off from raw pitch.
FIG. 14 is an X-ray analysis of the graphitized foam produced by the process of this invention.
FIGS. 15A–C are photographs illustrating foam produced with aluminum crucibles and the smooth structure or face sheet that develops.
FIG. 16A is a schematic view illustrating the production of a carbon foam composite made in accordance with this invention.
FIG. 16B is a perspective view of the carbon foam composite of this invention.
DETAILED DESCRIPTION OF THE INVENTION
In order to illustrate the carbon foam heat sink product of this invention, the following examples are set forth. They are not intended to limit the invention in any way.
EXAMPLE 1
Device for Thawing Food
Acetic acid has a heat of melting of 45 J/g at a melting point of 11° C. The heat of melting of food, primarily ice, is roughly 79 J/g at 0° C. Therefore, take a block of foam and fill it with liquid acetic acid at room temp. The foam will be encased in a box made from an insulating polymer such as polyethylene on all sides except the top. The top of the foam/acetic acid block will be capped with a high thermal conductivity aluminum plate that snaps into place thus sealing the foam/acetic acid inside the polymer case (illustrated in FIG. 1 ). If the foam block is 10-in.×15-in.×0.5-in. thick, the mass of foam is 614 grams. The mass of acetic acid that fills the foam is roughly 921 grams. Therefore, when a piece of frozen meat is placed in contact with the top of the aluminum block, the foam will cool to the freezing point of the acetic acid (11° C.). At this point, the heat given off from the acetic acid as it freezes (it also remains at 11° C.) will be equivalent to 49 KJ. This heat is rapidly transferred to the frozen meat as it thaws (it also remains at 0° C.). This amount of heat is sufficient to melt roughly 500 grams (1 lb.) of meat.
EXAMPLE 2
Heat Sink to Prevent Overheating of Satellites During Cyclic Orbits
Produce a carbon—carbon composite with the foam in which the foam is a core material with carbon—carbon face sheets ( FIG. 2 ). Fill the foam core with a suitable phase change material, such as a paraffin wax, that melts around the maximum operating temperature of the satellite components. One method to perform this would be to drill a hole in one surface of the carbon—carbon face sheets and vacuum fill the phase change material in the liquid state into the porous foam. Once filled, the sample can be cooled (the phase change material solidifies) and the hole can be plugged with an epoxy or screw-type cap. The epoxy and any other sealant must be able to withstand the operating temperature of the application. The foam-core composite will then be mounted on the side of the satellite that is exposed to the sun during orbit. As the satellite orbits the earth and is exposed to the sun, the radiant energy from the sun will begin to heat the composite panel to the melting point of the phase change material. At this point, the panel will not increase in temperature as the phase change material melts. The amount of radiant energy the panel can absorb will be dependent on the thickness and outer dimensions of the panel. This can be easily calculated and designed through knowledge of the orbit times of the satellite such that the material never completely melts and, thus, never exceeds the melt temperature. Then, when the satellite leaves the view of the sun, it will begin to radiate heat to space and the phase change material will begin to freeze. The cycle will repeat itself once the satellite comes into view of the sun once again.
EXAMPLE 3
Heat Sink for Leading Edges
Currently, the shuttle orbiter experiences extreme heats during reentry. Specifically, the leading edges of the craft can reach 1800° C. and the belly of the craft can reach temperatures as high as 1200° C. If a foam core composite panel is placed at the surface of the leading edges and at the surface of the belly ( FIG. 3 ), it would be able to absorb enough energy to dramatically reduce the maximum temperature of the hot areas. This also would permit a faster re-entry or (steeper glide slope) and maintain the current maximum temperatures. In this case the phase change material would most likely be an alloy, e.g. germanium-silicon, which melts around 800–900C and does not vaporize until much higher than the maximum temperature of the craft.
For example, Germanium has a heat of formation (heat of melting) of 488 J/g. This would require 1.0 Kg of Germanium to reduce the temperature of 1 Kg of existing carbon/carbon heat-shield by 668° C. In other words, if the existing carbon—carbon were replaced pound-for-pound with germanium filled foam, the maximum temperature of the heat shield would only be about 1131° C. instead of about 1800° C. during re-entry, depending on the duration of thermal loading.
EXAMPLE 4
Pitch powder, granules, or pellets are placed in a mold with the desired final shape of the foam. These pitch materials can be solvated if desired. In this example, Mitsubishi ARA-24 mesophase pitch was utilized. A proper mold release agent or film is applied to the sides of the mold to allow removal of the part. In this case, Boron Nitride spray and Dry Graphite Lubricant were separately used as a mold release agent. If the mold is made from pure aluminum, no mold release agent is necessary since the molten pitch does not adhere to the aluminum and, thus, will not stick to the mold. Similar mold materials may be found that the pitch does not adhere and, thus, they will not need mold release. The sample is evacuated to less than 1 torr and then heated to a temperature approximately 50 to 100° C. above the softening point. In this case where Mitsubishi ARA24 mesophase pitch was used, 300° C. was sufficient. At this point, the vacuum is released to a nitrogen blanket and then a pressure of up to 1000 psi is applied. The temperature of the system is then raised to 800° C., or a temperature sufficient to coke the pitch which is 500° C. to 1000° C. This is performed at a rate of no greater than 5° C./min. and preferably at about 2° C./min. The temperature is held for at least 15 minutes to achieve an assured soak and then the furnace power is turned off and cooled to room temperature. Preferably the foam was cooled at a rate of approximately 1.5° C./min. with release of pressure at a rate of approximately 2 psi/min. Final foam temperatures for three product runs were 500° C., 630° C. and 800° C. During the cooling cycle, pressure is released gradually to atmospheric conditions. The foam was then heat treated to 1050° C. (carbonized) under a nitrogen blanket and then heat treated in separate runs to 2500° C. and 2800° C. (graphitized) in Argon.
Carbon foam produced with this technique was examined with photomicrography, scanning electron microscopy (SEM), X-ray analysis, and mercury porisimetry. As can be seen in the FIGS. 5–10 , the isochromatic regions under cross-polarized light indicate that the struts of the foam are completely graphitic. That is, all of the pitch was converted to graphite and aligned along the axis of the struts. These struts are also similar in size and are interconnected throughout the foam. This would indicate that the foam would have high stiffness and good strength. As seen in FIG. 10 by the SEM micrograph of the foam, the foam is open cellular meaning that the porosity is not closed. FIGS. 11 and 12 are results of the mercury porisimetry tests. These tests indicate that the pore sizes are in the range of 90–200 microns.
A thermogravimetric study of the raw pitch was performed to determine the temperature at which the volatiles are evolved. As can be seen in FIG. 14 , the pitch loses nearly 20% of its mass fairly rapidly in the temperature range between about 420° C. and about 480° C. Although this was performed at atmospheric pressure, the addition of 1000 psi pressure will not shift this effect significantly. Therefore, while the pressure is at 1000 psi, gases rapidly evolved during heating through the temperature range of 420° C. to 480° C. The gases produce a foaming effect (like boiling) on the molten pitch. As the temperature is increased further to temperatures ranging from 500° C. to 1000° C. (depending on the specific pitch), the foamed pitch becomes coked (or rigid), thus producing a solid foam derived from pitch. Hence, the foaming has occurred before the release of pressure and, therefore, this process is very different from previous art.
Samples from the foam were machined into specimens for measuring the thermal conductivity. The bulk thermal conductivity ranged from 58 W/m·K to 106 W/m·K. The average density of the samples was 0.53 g/cm 3 . When weight is taken into account, the specific thermal conductivity of the pitch derived from foam is over 4 times greater than that of copper. Further derivations can be utilized to estimate the thermal conductivity of the struts themselves to be nearly 700 W/m·K. This is comparable to high thermal conductivity carbon fibers produced from this same ARA24 mesophase pitch.
X-ray analysis of the foam was performed to determine the crystalline structure of the material. The x-ray results are shown in FIG. 14 . From this data, the graphene layer spacing (d 002 ) was determined to be 0.336 nm. The coherence length (L a,100 ) was determined to be 203.3 nm and the stacking height was determined to be 442.3 nm.
The compression strength of the samples were measured to be 3.4 MPa and the compression modulus was measured to be 73.4 MPa. The foam sample was easily machined and could be handled readily without fear of damage, indicating good strength.
It is important to note that when this pitch is heated in a similar manner, but only under atmospheric pressure, the pitch foams dramatically more than when under pressure. In fact, the resulting foam is so fragile that it could not even be handled to perform tests. Molding under pressure serves to limit the growth of the cells and produces a usable material.
EXAMPLE 5
An alternative to the method of Example 4 is to utilize a mold made from aluminum. In this case two molds were used, an aluminum weighing dish and a sectioned soda can. The same process as set forth in Example 4 is employed except that the final coking temperature was only 630° C., so as to prevent the aluminum from melting.
FIGS. 15A–C illustrate the ability to utilized complex shaped molds for producing complex shaped foam. In one case, shown in FIG. 15A , the top of a soda can was removed and the remaining can used as a mold. No release agent was utilized. Note that the shape of the resulting part conforms to the shape of the soda can, even after graphitization to 2800° C. This demonstrates the dimensional stability of the foam and the ability to produce near net shaped parts.
In the second case, as shown in FIGS. 15B and C employing an aluminum weight dish, a very smooth surface was formed on the surface contacting the aluminum. This is directly attributable to the fact that the molten pitch does not adhere to the surface of the aluminum. This would allow one to produce complex shaped parts with smooth surfaces so as to improve contact area for bonding or improving heat transfer. This smooth surface will act as a face sheet and, thus, a foam-core composite can be fabricated in-situ with the fabrication of the face sheet. Since it is fabricated together and an integral material no interface joints result, thermal stresses will be less, resulting in a stronger material.
The following examples illustrate the production of a composite material employing the foam of this invention.
EXAMPLE 6
Pitch derived carbon foam was produced with the method described in Example 4. Referring to FIG. 16A the carbon foam 10 was then machined into a block 2″×2″×½″. Two pieces 12 and 14 of a prepeg comprised of Hercules AS4 carbon fibers and ICI Fibirite Polyetheretherkeytone thermoplastic resin also of 2″×2″×½″ size were placed on the top and bottom of the foam sample, and all was placed in a matched graphite mold 16 for compression by graphite plunger 18 . The composite sample was heated under an applied pressure of 100 psi to a temperature of 380° C. at a rate of 5° C./min. The composite was then heated under a pressure of 100 psi to a temperature of 650° C. The foam core sandwich panel generally 20 was then removed from the mold and carbonized under nitrogen to 1050° C. and then graphitized to 2800° C., resulting in a foam with carbon-carbon facesheets bonded to the surface. The composite generally 30 is shown in FIG. 16B .
EXAMPLE 7
Pitch derived carbon foam was produced with the method described in Example 4. It was then machined into a block 2″×2″×½″. Two pieces of carbon-carbon material, 2″×2″×½, were coated lightly with a mixture of 50% ethanol, 50% phenolic Durez© Resin available from Occidental Chemical Co. The foam block and carbon-carbon material were positioned together and placed in a mold as indicated in Example 6. The sample was heated to a temperature of 150° C. at a rate of 5° C./min and soaked at temperature for 14 hours. The sample was then carbonized under nitrogen to 1050° C. and then graphitized to 2800° C., resulting in a foam with carbon-carbon facesheets bonded to the surface. This is also shown generally at 30 in FIG. 16B .
EXAMPLE 8
Pitch derived carbon foam was produced with the method described in Example 4. The foam sample was then densified with carbon by the method of chemical vapor infiltration for 100 hours. The density increased to 1.4 g/cm 3 , the flexural strength was 19.5 MPa and the flexural modulus was 2300 MPa. The thermal conductivity of the raw foam was 58 W/m·K and the thermal conductivity of the densified foam was 94 W/m·K.
EXAMPLE 9
Pitch derived carbon foam was produced with the method described in Example 4. The foam sample was then densified with epoxy by the method of vacuum impregnation. The epoxy was cured at 150° C. for 5 hours. The density increased to 1.37 g/cm 3 and the flexural strength was measured to be 19.3 MPa.
Other possible embodiments may include materials, such as metals, ceramics, plastics, or fiber-reinforced plastics bonded to the surface of the foam of this invention to produce a foam core composite material with acceptable properties. Additional possible embodiments include ceramics, glass, or other materials impregnated into the foam for densification.
Based on the data taken to date from the carbon foam material, several observations can be made outlining important features of the invention that include:
1. Pitch-based carbon foam can be produced without an oxidative stabilization step, thus saving time and costs.
2. High graphitic alignment in the struts of the foam is achieved upon graphitization to 2500° C., and thus high thermal conductivity and stiffness will be exhibited by the foam, making them suitable as a core material for thermal-applications.
3. High compressive strengths should be achieved with mesophase pitch-based carbon foams, making them suitable as a core material for structural applications.
4. Foam core composites can be fabricated at the same time as the foam is generated, thus saving time and costs.
5. Rigid monolithic preforms can be made with significant open porosity suitable for densification by the Chemical Vapor Infiltration method of ceramic and carbon infiltrants.
6. Rigid monolithic preforms can be made with significant open porosity suitable for activation, producing a monolithic activated carbon.
7. It is obvious that by varying the pressure applied, the size of the bubbles formed during the foaming will change and, thus, the density, strength, and other properties can be affected.
The following alternative procedures and products can also be effected by the process of this invention:
1. Fabrication of preforms with complex shapes for densification by CVI or Melt Impregnation.
2. Activated carbon monoliths with high thermal conductivity.
3. Optical absorbent.
4. Low density heating elements.
5. Firewall Material
6. Low secondary electron emission targets for high-energy physics applications.
The present invention provides for the manufacture of pitch-based carbon foam heat sink for structural and thermal composites. The process involves the fabrication of a graphitic foam from a mesophase or isotropic pitch which can be synthetic, petroleum, or coal-tar based. A blend of these pitches can also be employed. The simplified process utilizes a high pressure high temperature furnace and thereby, does not require and oxidative stabilization step. The foam has a relatively uniform distribution of pore sizes (−100 microns), very little closed porosity, and density of approximately 0.53 g/cm 3 . The mesophase pitch is stretched alone the struts of the foam structure and thereby produces a highly aligned graphitic structure in the struts These struts will exhibit thermal conductivities and stiffness similar to the very expensive high performance carbon fibers (such as P-120 and K1100). Thus, the foam will exhibit high stiffness and thermal conductivity at a very low density (−0.5 g/cc). This foam can be formed in place as a core material for high temperature sandwich panels for both thermal and structural applications, thus reducing fabrication time. By utilizing an isotropic pitch, the resulting foam can be easily activated to produce a high surface area activated carbon. The activated carbon foam will not experience the problems associated with granules such as attrition, channeling, and large pressure drops. | A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to flow control valves, and particularly to the type of valve responsive to displacement thereof from an upright orientation to shut off flow.
A valve of the type under consideration may be employed as a safety device to prevent flow of a hazardous fluid in the event of an abnormal physical disturbance of a system in which such a valve is employed. More specifically, such valve, hereinafter termed "tilt-responsive valve," may be used to eliminate leakage of gasoline or other flammable fluid fuels in a motor vehicle in the event of an upset or rollover of the vehicle resulting from a collision or other circumstances.
A tilt-responsive valve may be provided in a fuel supply circuit between the supply tank and engine. For example, in a conventional passenger car, aspirated through a carburetor, the tilt valve may be arranged between a fuel pump and the carburetor to prevent leakage from the carburetor. Generally, a tilt-responsive valve includes means operative in response to overturning of the vehicle, and therefore the valve itself, to shut off a flow passage through the valve. Examples of valves in which operative means include a pendulum structure are disclosed in U.S. Pat. Nos. 2,082,723 to Seward, Jr.; 2,194,348 to Zoder; 2,258,323 to Gray; and 2,343,663 to Gregory. An additional disclosure of a tilt-responsive valve is shown in U.S. Pat. No. 535,556 to Robinson.
SUMMARY OF THE INVENTION
The invention provides a tilt-responsive valve in which a valve closure member is spring-biased to a closed position and a pendulum operator prevents closure of the valving member when the valve body is in a vertical or near-vertical orientation. When the valve is rotationally displaced beyond a normal tilt angle, the closure member is released by the pendulum operator to reach its closed position. The spring-biasing force on the closure member advantageously damps movement of the valve elements during normal operation, eliminates random movement of otherwise loose elements, and prevents severe impact loading of the sealing surfaces during sudden extremes of full displacement of the pendulum operator.
The elements of the valve, in accordance with the invention, are arranged in such a manner that the sealing force on the closure member, upon closure, is augmented in direct relation to the pressure of the fluid being checked. This feature permits the valve elements to be relatively light in construction and the normal operating forces to be correspondingly low, thereby allowing the valve to be economically produced and characterized by a relatively long service life.
In a preferred embodiment, the tilt valve closure member and pendulum operator are arranged along a common vertical axis, with the closure member and pendulum on opposite sides of a valve seat. A spring integrally formed with the closure member biases the latter towards a closed position on the seat while an extension of the pendulum above its pivot point normally engages the closure member and prevents it from sealing the valve seat. When the body of the valve is tilted beyond a critical angle, as when the vehicle to which it is attached overturns, the pendulum extension swings out of an interference path with the closure member, allowing it to close.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic perspective view of a motor vehicle, including a fuel supply system, on which a tilt-responsive valve is provided in accordance with the present invention;
FIG. 2 is a cross sectional view of an enlarged scale of the tilt-responsive valve of the invention;
FIG. 3 is a view similar to FIG. 2, illustrating the valve in a tilted and closed position;
FIG. 4 is a perspective view of a valve closure member and integral spring-biasing element;
FIG. 5 is a fragmentary view of a modified pendulum pivot point, integral with the valve body, used where it is desired to limit pivotal movement of the pendulum to a single plane;
FIG. 6 is a fragmentary view of the modified pivot point of FIG. 4 in its relationship with an associated area of the pendulum; and
FIGS. 7 and 8 are fragmentary views of a modified valve closure and pendulum extension for maintaining substantially full flow through the valve until the actual point of valve closure upon reaching a critical tilt angle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a conventional passenger car or other motor vehicle 10 having a fuel supply system including a supply tank 11 and a fuel line 12 extending from the tank to a carburetor 13 or other device for distributing fuel to the combustion area of the vehicle's engine (not shown). The supply system may include a fuel pump 14 driven directly by the engine or an auxiliary electric motor according to conventional practice. In the fuel supply system, preferably between the fuel pump 14 and carburetor 13, a tilt-responsive valve 15 is provided.
A body of the tilt valve 15 includes a lower housing section 17, an intermediate valving section 18, and an upper end cap section 19. The various sections 17, 18, and 19 are molded or otherwise formed of suitable material compatible with each other and suitable for containing hydrocarbon fuel such as gasoline. The sections 17, 18, and 19 may be of plastic, for example, and are welded, adhesively secured, or otherwise joined in fluidtight relation. The upper end cap 19 includes an inlet nipple 22 adapted to be received in a hose forming a portion of the supply line 12. The lower housing section 17 provides a similar nipple 23 adapted to be similarly connected to a hose portion of the line leading to the carburetor 13. The end cap 19 forms a wall closure for a generally cylindrical operating chamber 24 for a valve closure member 27. A passage 28 of the nipple 22 conducts fluid into the operating chamber 24.
At a lower end of the chamber 24, there is provided a conical valve seat surface 29 defining a central, vertical axis through the valve 15. It will be understood that various other annular valve seat surfaces may be employed, such as a spherical surface or an edge surface formed by intersecting surface planes. A peripheral ledge 30 extends radially outwardly from the seat 29 to a cylindrical wall surface 31 defining the cylindrical chamber 24.
The valving member 27 (FIG. 4) is molded or otherwise formed of elastomeric material suitable for use with hydrocarbon fuel. The closure member 27 includes a lower spherical portion 34 dimensioned to seal against the conical seat 29 in the manner of a check valve. Immediately adjacent the spherical closure portion 34 is an integral radial flange or shoulder 35 adapted to rest on the adjacent body ledge 30 when the valving member 27 assumes a cocked orientation within the valve body, as shown in FIG. 2.
Integral with the closure member 27 is a columnar spring element 37 which extends upwardly into a receiving pocket 38 in the end wall 19. The pocket 38 centers the distal end of the spring element 37 on the axis of the valve. The spring element 37 is dimensioned with sufficient length to be deflected when assembled into a buckling mode to resiliently bias the closure member 27 axially towards the seat 29 and maintain a slight biasing force on the closure member when it is seated on this surface, as illustrated in FIG. 3. Where desired, various other structural arrangements for the spring element 37 may be employed, including helical configurations and/or elements which are nonintegral with the valving member 27.
The valve seat 29 communicates with a hemispherical cavity 41 in the lower housing 17. A passage 42 in the outlet nipple 23 exhausts fluid from this cavity 41. An integral post 43 extends axially upwardly from a lower side of the housing section 17 and includes at its distal end a spherical or ball segment 44 for pivotally supporting a hollow, conical pendulum 46. The underside of the apex of the cone 46 includes an integral spherical socket 47 in which the ball segment 44 is pivotally received. The pendulum 46 is molded or cast of suitable material for service with hydrocarbon fuels. The pendulum 46 has embedded within a lower end of its conical skirt a ring 48 of high density material, such as lead, which comprises a majority of the mass of the pendulum. This skirt may be apertured as at 45.
Above the pivot socket 47 and along the axis of the pendulum 46, defined by its conical skirt portion, is an integral camming finger 49 which is adapted to engage a lower camming surface 51 of the valving member 27. The pendulum camming finger 49 is arranged to control the valving member 27 by holding it open or out of sealing contact with the seat 29 when the body of the valve 15 is in the upright position of FIG. 2 and within an angle of tilt within a normal operational range from the vertical. As shown in FIG. 3, when the body of the valve 15 has been rotated through an angle greater than a critical angle, the camming finger is displaced radially and axially, by rocking movement, from the path of the valving or closure member 27 by the influence of gravity on the pendulum 46. A clearance angle 53 within the pendulum 46, reduced by an angle 54 defined by the post 43, is at least twice as wide as the critical tilt angle to permit full pivotal displacement of the pendulum and release of the valving member 27.
The body of the valve 15 is suitably fixed relative to the body of the vehicle 10 such that the valve assumes the attitude of the vehicle. In the event of an upset of the vehicle 10, as by collision or other mishap, the pendulum 46 of the valve will assume the valve closing position of FIG. 3 relative to the valve body, including situations where the valve body is tilted in excess of the critical angle, for example, where the valve body is rotated 90 degrees as where the vehicle comes to rest on its side or end, and 180 degrees where the vehicle comes to rest on its top. The universal mounting provided by the ball and socket elements 44 and 47 allows the valve 15 to be responsive to upsets of the vehicle about a longitudinal axis, i.e., side-over-side and/or about a lateral axis, i.e., end-over-end. Since the valving closure member 27 is arranged on the upstream side of the valve seat 29 with respect to the normal direction of fluid flow through the valve 15, the closing force on it, upon seating, is augmented in direct relation to the pressure of the fluid being checked.
FIGS. 5 and 6 illustrate a modification of the pivot area of the post, designated 43a, and the pendulum designated 46a. The post 43a includes a cylindrical support surface 58 on a triangular, planar tab 59 formed at its top. Concentric with the cylindrical surface 58 is a bore 61 transverse through the body of the tab 59. The pendulum 46a has a blind slot 62 formed in the underside of its apex and dimensioned to fit over the triangular tab 59, as indicated in FIG. 6. A retaining pin 63 is inserted through the pivot tab hole 61 and suitable holes in the pendulum to lock these members together while allowing pivotal movement in the plane of the tab 59. The structure of FIGS. 5 and 6 is employed where it is desired to limit the sensitivity and operation of the pendulum 46a and valve 15 to only one plane.
FIGS. 7 and 8 illustrate a modified arrangement of the pendulum and valving members designated 46b and 27b, respectively. As shown, a pendulum camming finger 49b includes a spherical camming surface 71 at its upper or distal end. This surface 71 is arranged to engage a mating surface 72 on the underside of the valving member 27b. The arcuate length of the spherical surface 71 is arranged to maintain the valve closure member 27b in a normally and fully open position until a critical angle, shown in FIG. 8, is reached and the surface slips out from under the surface 72.
The disclosed valve structure when empoyed in series in the fuel supply line of a motor vehicle is adapted to prevent flow through the line upon upset of such vehicle. In both of the embodiments of FIGS. 2, 3, and 7,8, the mass of the pendulum 46,46b is arranged to reopen the valving member 27,27b when the vehicle is uprighted. The disclosed valve 15 is adapted for use with various types of hydrocarbon fuels other than conventional gasoline, both liquid and gaseous, and in systems other than a motor vehicle. In such instances, the materials chosen for the various valve elements are selected in accordance with their intended use. The spring-biasing force on the valving members 27,27b provided by the biasing spring element 37 maintains contact between the valving member and pendulum during normal operation, and thereby tends to advantageously damp motion of the elements and avoid vibration-induced impacts between elements of the valve.
While the invention has been described in connection with specific embodiments thereof, it is to be clearly understood that this is done only by way of example, and not as a limitation to the scope of the invention as set forth in the objects thereof and in the appended claims. | A tilt-responsive valve particularly suited for use in a fuel supply system in a motor vehicle for preventing leakage of fuel in the event of upset of the vehicle. The valve includes a closure member biased to a closed position and a pendulum control member for preventing sealing of the closure member when the valve is in a normal range of inclination from the vertical and permitting the closure member to check flow through the valve when the valve is tilted beyond a critical angle. | 8 |
TECHNICAL FIELD
The present invention relates to an extracting device supplying fixed quantity of exhaust gas for industrial facility, and more particularly, to an extracting device supplying fixed quantity of exhaust gas for industrial facility which supplies a certain amount of exhaust gas by installing a gas supply pipe, in which two blowers are arranged in a line, at a stack and operating each blower in accordance with a predetermined input value.
BACKGROUND ART
Due to emission of greenhouse gas caused by the use of fossil fuels, global warming has resulted in changes in climate and global environment, thereby threatening the survival of all living things on earth including human beings. Accordingly, various researches and developments for reducing carbon dioxide are now in progress. As one of efforts, study on the way of capturing and biologically converting carbon dioxide is actively underway.
As a green plant which performs photosynthesis for biologically converting carbon dioxide, microalgae have been actively studied. In common with other green plants in photosynthetic process, microalgae, phytoplankton, use sun as an energy source and grow up with photosynthesis for biofixation of carbon dioxide.
The first reason for recognizing microalgae as a means of biofixation of carbon dioxide is very low amount of energy to be injected for capturing carbon dioxide, because solar energy may be the main energy source as the same with absorption of carbon dioxide. Thus, since there is less amount of generating carbon dioxide for operation of biofixation of carbon dioxide, removal efficiency is high in terms of profit balance of carbon dioxide.
Secondly, required size of site is small because of very high speed of fixation of carbon dioxide as compared to green plants. According to results from study conducted at Tokyo Electric Power Research Institute, it is revealed that the speed of fixation of carbon dioxide of microalgae is more than 8 times higher than that of macroalgae and more than 16 times higher than that of pine trees, the most common tree in Korea.
Besides, there is an advantage in that processes for separating and concentrating carbon dioxide are not required due to direct fixation of carbon dioxide from combustion gas. Moreover, microalgae, generated from carbon dioxide fixation, contain numerous useful materials, thereby being utilized for manufacture of expensive bioproducts.
However, if the carbon dioxide fixation process using microalgae is conducted by bioreactors applied to industries, it takes too much electric energy. Thus, it is not easy to supply light energy which is necessarily required for energy saving and microalgae growth.
To solve a problem, Korean Patent Registration no. 10-1072844 (DEVICE FOR CULTIVATING MICROALGAE BY USING EMITTED GAS FROM POWER PLANT) was filed and published.
As illustrated in FIG. 1 , the device for cultivating microalgae by using emitted gas from power plant includes a cultivation area ( 10 ), an exhaust gas supply area ( 20 ) and a microalgae extraction area ( 30 ).
The cultivation area ( 10 ) consists of a photosynthesis reactor ( 11 ) for cultivating microalgae, which is microbial, and a light emitting member ( 13 ) for shining light on the photosynthesis reactor ( 11 ). Installed to the inside of a greenhouse for maintaining optimal temperature, the cultivation area ( 10 ) is provided with exhaust gas from a power plant ( 1 ) through the exhaust gas supply area ( 20 ).
Specifically, the photosynthesis reactor ( 11 ) has a plurality of exhaust gas supply lines ( 15 ) for effectively supplying exhaust gas, coming from the exhaust gas supply area ( 20 ), and a shut-off valve ( 15 a ) in each exhaust gas supply line ( 15 ). Also, the photosynthesis reactor ( 11 ) has a drain line ( 17 ) for emitting microalgae, which stays inside, and a water supply line ( 19 ) for adding water toward the inside.
The photosynthesis reactor ( 11 ) not only balances cultivation environment of microalgae by means of carbon dioxide (CO 2 ) and heat in exhaust gas, but increases the amount of cultivated microalgae.
The light emitting member ( 13 ) is used for stimulating cultivation of microalgae at night or a cloudy day.
The exhaust gas supply area ( 20 ) connects the power plant ( 1 ) and the cultivation area ( 10 ) for supplying exhaust gas, generated from the power plant ( 1 ), to the cultivation area ( 10 ).
The exhaust gas supply area ( 20 ) consists of a vent fan ( 21 ), a filter member ( 23 ) and a heat exchanging area ( 25 ).
Connected to a vent line ( 3 ) of the power plant ( 1 ), the vent fan ( 21 ) compulsorily draws in part of exhaust gas emitted to a stack ( 5 ) throughout the vent line ( 3 ) and then, delivers to the photosynthesis reactor ( 11 ).
The filter member ( 23 ) eliminates foreign substances contained in exhaust gas which is discharged by the vent fan ( 21 ).
The heat exchanging area ( 25 ) performs heat exchange of exhaust gas to reduce temperature of exhaust gas which passes through the filter member ( 23 ).
Property reduced temperature in the heat exchanging area ( 25 ), exhaust gas is supplied to the photosynthesis reactor ( 11 ) throughout a supply line ( 15 ), thereby making carbon dioxide eliminated.
The microalgae extraction area ( 30 ) is comprised of a drainage pump ( 31 ), installed in the drain line ( 17 ) of the photosynthesis reactor ( 11 ); a storage tank ( 33 ) for storing water discharged from the drain line ( 17 ); and a separation member ( 35 ) for separating water and microalgae.
The drainage pump ( 31 ) compulsorily discharges microalgae, cultivated in the photosynthesis reactor ( 11 ), to the storage tank ( 33 ). When microalgae is compulsorily discharged by the drainage pump ( 31 ), water in the photosynthesis reactor ( 11 ) is discharged together.
The storage tank ( 33 ) is connected to the separation member ( 35 ), and water, contained inside, is supplied to the separation member ( 35 ).
The separation member ( 35 ) consists of a centrifuge ( 35 a ) for separating water and microalgae by means of turning force and water of the storage tank ( 35 ); and a storage tank ( 35 b ) for storing water, discharged from the centrifuge ( 35 a ).
There are a plurality of centrifuges ( 35 a ) for optimizing efficiency in microalgae separation, and water, coming from microalgae separation, is discharged to the storage tank ( 35 b ). Although two centrifuges ( 35 a ) are illustrated in the present embodiment, the number of centrifuges ( 35 a ) may be one or more than three in accordance with a need of a user.
Discharged to the storage tank ( 35 b ) and fed to the heat exchanging area ( 25 ) by means of a drain water supply area ( 40 ), water is used as a medium of heat exchange of the heat exchanging area ( 25 ).
The drain water supply area ( 40 ) comprises a connection line ( 41 ) for connecting the storage tank ( 35 b ) and the heat exchanging area ( 25 ) in order to transfer water of the storage tank ( 35 b ) to the heat exchanging area ( 25 ); and a feed pump ( 43 ) installed on the connection line ( 41 ).
However, the traditional device for cultivating microalgae by using emitted gas from power plant includes the vent fan in the vent line. Thus, emitted gas is not actively supplied by differential gas pressure, and the photosynthesis reactor of the cultivation area is damaged by pressure or water is overflowed because of pulsatory supply.
In addition, in the traditional device for cultivating microalgae by using emitted gas from power plant, moisture in emitted gas makes the vent line full of water. Thus, it causes breakdown of the vent fan and gives a bad influence on microalgae growth due to water inflow into a photosynthesis cultivator.
PRIOR ART
Reference
Korean Patent Registration No. 10-1072844
DISCLOSURE
Technical Problem
For solving above problems, the object of the present invention is to provide an extracting device supplying fixed quantity of exhaust gas for industrial facility which supplies a certain amount of exhaust gas by installing a gas supply pipe, in which two blowers are arranged in a line, at a stack and operating each blower in accordance with a predetermined input value.
Further, the other object of the present invention is to provide the extracting device supplying fixed quantity of exhaust gas for industrial facility which blocks water inflow into sources by installing the gas supply pipe vertically to a stack, condensing moisture in exhaust gas at the end of the gas supply pipe, installing a valve for discharging condensed water toward the outside, supplying exhaust gas to a blower with a branch gas pipe at a higher position than a level of condensed water of the gas supply pipe, and installing a trap to a connection pipe, which is extended for supplying exhaust gas, coming from the blower, to demanders.
Technical Solution
To accomplish above objects, the present invention comprises: a first gas supply pipe configured to extract part of exhaust gas from a stack and to form a first horizontal area, installed on top for horizontally penetrating into the side of the stack, a vertical area, vertically bent from the first horizontal area in the direction of ground, and a second horizontal area, horizontally located from the vertical area; a first branch gas supply pipe configured to be installed at the bottom side of the vertical area of the first gas supply pipe; a second branch gas supply pipe configured to be connected in parallel to the first branch gas supply pipe at the bottom side of the vertical area of the first gas supply pipe; a second gas supply pipe configured to supply exhaust gas, coming from the first branch gas supply pipe and the second branch gas supply pipe, to sources; a first blower configured to be operated in accordance with external power control at the first branch gas supply pipe; a second blower configured to be operated in accordance with external power control at the second branch gas supply pipe; a first pressure gauge configured to be installed on the first branch gas supply pipe and output a contact signal if the measured internal pressure of the pipe is out of a predetermined range of a first reference pressure value; a second pressure gauge configured to be installed on the second branch gas supply pipe and output a contact signal if the measured internal pressure of the pipe is out of a predetermined range of a second reference pressure value; and a switching element configured to supply the first and second blowers to power in accordance with the contact signal, outputted from the first and second pressure gauges.
Hereinafter, the extracting device supplying fixed quantity of exhaust gas for industrial facility further comprises an inverter which soft starts the first and second blowers.
Hereinafter, the first horizontal area of the first gas supply pipe includes a main valve for supplying and blocking exhaust gas.
Hereinafter, the first horizontal area of the first gas supply pipe is located to the side of the stack while keeping a certain distance from the ground for the purpose of supplying homogenous exhaust gas.
Hereinafter, the first gas supply pipe includes a solenoid valve for automatically discharging condensed water from the end of the second horizontal area toward the outside.
Hereinafter, the second gas supply pipe includes a trap for discharging condensed water toward the outside.
Hereinafter, the contact signal of the first pressure gauge outputs a contact signal which turns off the switching element if the pressure is over the predetermined range of the first reference pressure value, and outputs a contact signal which turns on the switching element if the pressure is less than the predetermined range of the first reference pressure value.
Hereinafter, the contact signal of the second pressure gauge outputs a contact signal which turns off the switching element if the pressure is over the predetermined range of the second reference pressure value, and outputs a contact signal which turns on the switching element if the pressure is less than the predetermined range of the second reference pressure value.
Hereinafter, the second pressure gauge sets up the range of the second reference pressure value in the range of the first reference pressure value of the first pressure gauge.
Advantageous Effects
According to the extracting device supplying fixed quantity of exhaust gas for industrial facility of the present invention, as constituted above, it enables to supply a certain amount of exhaust gas by installing a gas supply pipe, in which two blowers are arranged in a line, at a stack and operating each blower in accordance with a predetermined input value.
Further, according to the present invention, it enables to block water inflow into sources by installing the gas supply pipe vertically to a stack, condensing moisture in exhaust gas at the end of the gas supply pipe, installing a valve for discharging condensed water toward the outside, supplying exhaust gas to a blower with a branch gas pipe at a higher position than a level of condensed water of the gas supply pipe, and installing a trap to a connection pipe, which is extended for supplying exhaust gas, coming from the blower, to demanders.
DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a diagram showing the configuration of a conventional device for cultivating microalgae by using emitted gas from power plant.
FIG. 2 illustrates a schematic diagram showing the configuration of an extracting device supplying fixed quantity of exhaust gas for industrial facility according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The configuration of an extracting device supplying fixed quantity of exhaust gas for industrial facility, according to the present invention, will be described in detail with the accompanying drawing.
In the following description of the present invention, a detailed description of known incorporated functions and configurations will be omitted when to include them would make the subject matter of the present invention rather unclear. Also, the terms used in the following description are defined taking into consideration the functions provided in the present invention. The definitions of these terms should be determined based on the whole content of this specification, because they may be changed in accordance with the option of a user or operator or a usual practice.
FIG. 2 illustrates a schematic diagram showing the configuration of an extracting device supplying fixed quantity of exhaust gas for industrial facility according to the present invention.
Referring to FIG. 2 , an extracting device supplying fixed quantity of exhaust gas for industrial facility ( 100 ) according to the present invention comprises a first gas supply pipe ( 110 ), a first branch gas supply pipe ( 120 ), a second branch gas supply pipe ( 130 ), a second gas supply pipe ( 140 ), a first blower ( 150 ), a second blower ( 160 ), a first pressure gauge (P 1 ), a second pressure gauge (P 2 ), and a switching element ( 170 ).
First, extracting part of exhaust gas from a stack, the first gas supply pipe ( 110 ) comprises a first horizontal area ( 111 ) formed on top for horizontally penetrating into the side of a stack; a vertical area ( 113 ) vertically bent from the first horizontal area ( 111 ) in the direction of ground; and a second horizontal area ( 115 ) horizontally formed from the vertical area ( 113 ). Hereinafter, the first horizontal area ( 111 ) of the first gas supply pipe ( 110 ) includes a main valve ( 117 ) for supplying and blocking exhaust gas, and is installed to the side of the stack while keeping a certain distance (e.g., 30M as for 80M stack) from the ground for the purpose of supplying homogenous exhaust gas. Hereinafter, the first gas supply pipe ( 110 ) comprises a solenoid valve ( 119 ) for automatically discharging condensed water from the end of the second horizontal area ( 115 ) toward the outside.
In addition, the first branch gas supply pipe ( 120 ) is installed on the bottom side of the vertical area ( 113 ) of the first gas supply pipe ( 110 ). At this time, it is desirable that a diameter of the first branch gas supply pipe ( 120 ) is smaller than that of the first gas supply pipe ( 110 ).
In addition, the second branch gas supply pipe ( 130 ) is connected in parallel to the first branch gas supply pipe ( 120 ) at the bottom side of the vertical area of the first gas supply pipe ( 110 ). At this time, it is desirable that a diameter of the second branch gas supply pipe ( 130 ) is smaller than that of the first gas supply pipe ( 110 ).
Further, the second gas supply pipe ( 140 ) supplies exhaust gas, coming from each of the first branch gas supply pipe ( 120 ) and the second branch gas supply pipe ( 130 ), to sources such as a microalgae cultivator and an absorption tower. Hereinafter, the second gas supply pipe ( 140 ) includes a trap ( 141 ) for discharging condensed water, which comes from gas supply, toward the outside.
Continuously, installed on the first branch gas supply pipe ( 120 ), the first blower ( 150 ) is operated in accordance with power control of a switching element ( 170 ), as explained below, and is fed with exhaust gas of the first gas supply pipe through the first branch gas supply pipe ( 120 ) to the second gas supply pipe ( 140 ).
Next, installed on the second branch gas supply pipe ( 130 ), the second blower ( 160 ) is operated in accordance with power control of the switching element ( 170 ), and is fed with exhaust gas of the first gas supply pipe through the second branch gas supply pipe ( 130 ) to the second gas supply pipe ( 140 ).
Further, installed on the first branch gas supply pipe ( 120 ), the first pressure gauge (P 1 ) measures internal pressure of the pipe and outputs a contact signal if the pressure is over or less than the predetermined range of a first reference pressure value. Hereinafter, if the pressure is over the predetermined range of the first reference pressure value, the first pressure gauge (P 1 ) outputs a contact signal which turns off the switching element ( 170 ), and if the pressure is less than the predetermined range of the first reference pressure value, the first pressure gauge (P 1 ) outputs a contact signal which turns on the switching element ( 170 ).
Furthermore, installed on the second branch gas supply pipe ( 130 ), the second pressure gauge (P 2 ) measures internal pressure of the pipe and outputs a contact signal if the pressure is over or less than the predetermined range of a second reference pressure value. Hereinafter, if the pressure is over the predetermined range of the second reference pressure value, the second pressure gauge (P 2 ) outputs a contact signal which turns off the switching element ( 170 ), and if the pressure is less than the predetermined range of the second reference pressure value, the second pressure gauge (P 2 ) outputs a contact signal which turns on the switching element ( 170 ). Here, it is desirable that the second pressure gauge (P 2 ) has a fast supply period with the second reference pressure value, which is set up in the range of the first reference pressure value of the first pressure gauge (P 1 ), for preventing generation of differential pressure or pulsation in case of exhaust gas supply to the second gas supply pipe ( 140 ). For instance, if the range of the first reference pressure value is 0.15-0.3 kgf/cm 2 , the range of the second reference pressure value is set to 0.15-0.3 kgf/cm 2 .
In addition, the switching element ( 170 ), as relay, is respectively installed at the first pressure gauge (P 1 ) and the second pressure gauge (P 2 ), thereby supplying or blocking power to the first blower ( 150 ) and the second blower ( 160 ).
Meanwhile, the extracting device supplying fixed quantity of exhaust gas for industrial facility according to the present invention further includes an inverter ( 180 ) for preventing damage, resulting from rapid start-up, by soft starting the first blower ( 150 ) and the second blower ( 160 ).
Hereinafter, the extracting device supplying fixed quantity of exhaust gas for industrial facility according to the present invention will be described in detail with the accompanying drawing.
First, if the main valve ( 170 ) is open, exhaust gas in a stack ( 101 ) is flowed into the first gas supply pipe ( 110 ).
In this condition, the first branch gas supply pipe ( 120 ) and the second branch gas supply pipe ( 130 ) do not have exhaust gas and their pressure is less than the range of the first and second reference pressure values. Thus, a signal is outputted from the first pressure gauge (P 1 ) and the second pressure gauge (P 2 ) for turning on the switching element ( 170 ).
Then, power is supplied to the first blower ( 150 ) and the second blower ( 160 ) with the switching element ( 170 ), which is operating.
Accordingly, flowing into the first branch gas supply pipe ( 120 ) and the second branch gas supply pipe ( 130 ), exhaust gas is supplied to sources such as microalgae cultivators, absorption towers throughout the second gas supply pipe ( 140 ).
In this condition, if pressure, measured in the first pressure gauge (P 1 ) or the second pressure gauge (P 2 ), is over the predetermined range of the first and second reference pressure value, the first pressure gauge (P 1 ) or the second pressure gauge (P 2 ) turns off the switching element ( 170 ), thereby blocking power supply to the first blower ( 150 ) or the second blower ( 160 ).
Continuously, exhaust gas is supplied to the second gas supply pipe ( 140 ) by repeatedly measuring pressure of the first pressure gauge (P 1 ) or the second pressure gauge (P 2 ).
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
INDUSTRIAL APPLICABILITY
The present invention is available in facilities for cultivating microalgae by means of exhaust gas, facilities for absorbing carbon dioxide in exhaust gas, etc.
EXPLANATIONS OF NUMERAL REFERENCE
110 , 140 : first and second gas supply pipes
120 , 130 : first and second branch supply pipes
150 , 160 : first and second blowers
170 : a switching element
180 : an inverter
P 1 , P 2 : first and second pressure gauges | The present invention relates to an extracting device supplying fixed quantity of exhaust gas for industrial facility, and more particularly, to an extracting device supplying fixed quantity of exhaust gas for industrial facility which supplies a certain amount of exhaust gas by installing a gas supply pipe, in which two blowers are arranged in a line, at a stack and operating each blower in accordance with a predetermined input value. | 8 |
BACKGROUND OF THE INVENTION
The invention concerns a method for controlling the beat-up in a loom, the reed being set to a target or desired beat-up distance.
Various alternatives are known for regulating the fell of the cloth in the loom to avoid start-up marks or blemishes in the fabric.
EP-A-350 446 discloses a method for operating a terry loom in which the sley is driven by the main drive of the loom and is actuated by a separate drive which is controlled, individually for each weft, by a series of freely programmable pulses. In this way the known terry rhythms with different pile heights can be executed.
SUMMARY OF THE INVENTION
It is an object of the invention to create a method for controlling the reed beat-up in a loom which avoids the formation of thick and/or thin areas in the fabric by varying the beat-up distance of the reed.
This object is achieved in accordance with the invention by reciprocating the reed over a predetermined beat-up distance towards and away from the fell during normal operation of the loom to beat-up the weft threads against the fell. Following a loom stoppage, the next weft yarn is beat-up against the last weft yarn over a compensated beat-up distance which is different from the predetermined beat-up distance. Thereafter the reed is again reciprocated over the predetermined beat-up distance during subsequent picks of the loom.
An advantage derived from the invention is that terry fabric and smooth fabric are manufactured which have the desired, pre-programmed uniform weft density so that the formation of fabric blemishes is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a terry loom using the method of the present invention;
FIG. 2 is a flow diagram of the course of the method for shutting down the machine when a mispick or weft fault occurs;
FIG. 3 is a flow diagram of the course of the method for shutting down the machine when a stop event occurs; and
FIG. 4 is a flow diagram of the course of the method for restarting the machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of the present invention is used to avoid weaving faults, the course of the method being dependent on whether a weft thread fault, e.g. a weft thread breakage, part weft, etc., or another stop event, e.g. warp thread breakage, switching-off of the loom, etc., occurred.
FIG. 1 shows a terry loom for carrying out the method of the present invention. A ground warp 7 runs from a ground warp beam 1 via a tensioning beam 4 to a shed 9. A fabric 10 is drawn off via a breast beam 6 and a take-off roller onto a cloth beam 3. A pile warp 8 is led from a pile warp beam 2 to shed 9 via an oscillating roller 5. A reed 12 of a sley 11 is driven by a loom main drive shaft 13 via a sley control means 14. Furthermore, a servomotor 15 is provided which is drivingly connected with the sley control means in order to set the beat-up distances. The servomotor 15 is connected electrically with a control means 16 in order to drive the servomotor 15 in accordance with a control program.
In the following, one embodiment of the method is described, which is applied during the weaving of three weft terry fabric.
FIG. 2 is a flow diagram and shows what happens when a weft thread breakage occurs during weaving 21. The appropriate monitoring means 22 sends a fault signal to the control means 16 which, in one control step, sets the sley control means 14 by means of the servomotor 15 to a partial beat-up distance 23 VD, VD being at least so much greater than VD target or AD target that the reed and a part weft which might be present no longer alters the position of the previously correctly inserted weft thread, i.e. a minimal distance from the previously correctly introduced weft thread is present. At this time, the main shaft of the loom turns until a stop position 24 is reached, at which a control step stop initiation 25 takes place. In the event that an automatic stop 26 of the loom is initiated, the main shaft is turned in the direction of motion in order to reach a predetermined shed position, for example the closed shed position 27. Subsequently, a control step weft search is initiated which, in dependence on the shed position, comprises two independent search processes 28. After completion of the appropriate search process, the loom is shut down at 29.
Referring now to FIG. 3, if another stop event 32, for example a warp thread breakage, a manual switch-off etc., occurs during the weaving process 31, the sley control means can, according to the invention, be set, by means 33 of the servomotor, to the partial beat-up distance VD max either directly after the stop event or before the reed reaches the full beat-up position a further time.
In the same way as in the case of a weft thread breakage, the second control step "stop initiation" 35 follows after the stop position 34 has been reached. If an automatic stop 36 is initiated, a control step "machine stop" 37 follows. If an equal positioning 38 of the shed is desired, the shed position is altered 39 in one control step. After the alteration of the shed position, or in the case of an unequal shed position, a control step "weft search" 40 is initiated. After completion of the weft search process, the loom is shut down and, after the fault has been rectified, it is prepared for restarting (FIG. 3).
In the control means 16 (FIG. 1) the characteristic values target partial beat-up distance, target full beat-up distance, weft density, number of terry picks until the full beat-up and fabric type are stored. Furthermore, a correction procedure can be stored as a function of these characteristic values, which determines the correction steps. It is pointed out that further characteristic values can be taken into account.
Furthermore, it is provided that the correction procedure can be input manually, independently of the stored characteristic values, in which case account can be taken of special features of the article being woven.
In doing this, the values of the partial beat-up distance and of the full beat-up distance are corrected when the loom is restarted. This correction takes place stepwise on the basis of correction steps which can be set manually and which are assigned to every beat-up and are repeated until the target beat-up distance for the partial beat-up weft and the full beat-up weft is reached. The correction can take place within one or several groups of picks. Here, the length change of the beat-up distance can be the same or different for each group or for each beat-up.
Referring to FIG. 4, restarting of the machine is initiated, as a rule, with a manually triggered start command 51. In one control step the loom is brought into a starting position 52. This process is independent of whether terry or smooth fabric is being manufactured.
During restarting of the machine, the sley control means is drivingly connected with the main shaft of the machine. In order to bring the loom from standstill into the operating condition, one or several lost picks 53 can be effected as the loom runs up to speed, with VD max 54 being set as the loom runs up to speed and with the number of lost picks being freely selectable.
FIG. 4 shows the method sequence during starting of the loom after a previous weft thread breakage. Taking account of the input parameters, and on the basis of the item of information that the first partial beat-up pick is broken, the partial beat-up distance VD 1 is set at 55, which is the sum of the target partial beat-up distance VD target plus/minus a correction value Vk 1 . Thus the first partial beat-up pick is displaced in the warp direction, e.g. in the case of a thin area in the fabric, by a distance greater than the target partial beat-up distance or, in the case of a thick area in the fabric, by a distance which is shorter than the target partial beat-up distance. Following this, the second partial beat-up pick is inserted and the partial beat-up distance VD 2 set, which is the sum of the target beat-up distance VD target plus/minus a correction value Vk 2 . In this way, the second partial beat-up pick is likewise displaced in the warp direction with respect to the target partial beat-up distance VD target . During insertion of the full beat-up weft, the beat-up distance AD 1 is set at 56, which is the sum of the target full beat-up distance AD target plus/minus a correction value Ak 1 . In this way, the group of picks is displaced in the warp direction with respect to the target full beat-up distance AD target . If the correct position of the group of picks with respect to the fell of the cloth is achieved by means of these correction processes, the further weaving process runs either without additional corrections to the values VD and AD, i.e. the fabric being manufactured has a weft density and loop height with the predetermined values, or with additional corrections for at least one further group of picks having values for VD and AD altered with respect to the group of picks that were previously beaten up. The correction values can have the same or different values.
If the correct position is not achieved, which can be determined on the basis of a visual or automatic monitoring, the values VD 1 , VD 2 and AD 1 are altered for the next similar fault event. If a thin area or thick area is detected in the fabric, then the full beat-up distance AD is altered. Specifically, the value of AD is increased in the case of a thin area and the value of AD is decreased in the case of a thick area. If a deviation in the loop height is determined, the values VD 1 and VD 2 are altered. Specifically, the values of VD 1 and VD 2 are decreased in the case of a loop which is too high and the values of VD 1 and VD 2 are increased in the case of a loop which is too low.
In the case of a warp thread breakage, after the loom has been run up to speed, the first pick is generally a full beat-up pick. For this reason, assuming the general case, the course of the method is described in the following.
With a control step "Full beat-up" the correction process is initiated and a beat-up distance AD 1 is set, which is the sum of the target full beat-up distance AD target plus/minus a correction value Ak 1 . In this way, the group of picks is correspondingly displaced in the warp direction by the target full beat-up distance AD target . If the correct position of the group of picks with respect to the fell of the cloth is achieved by means of this correction process, the further weaving process runs either without additional corrections to the values VD and AD, i.e. the fabric manufactured afterwards has a weft density and loop height with the specified values, or with further corrections for at least one further group of picks having values for VD and AD altered with respect to the group of picks that were previously beaten up. The correction values can have the same or different values (FIG. 4).
If the correct position is not achieved, which can be determined on the basis of a visual or automatic monitoring, the value is altered. If a thin area or thick area is detected in the fabric, then the full beat-up distance AD is altered, specifically, the value of AD is increased in the case of a thin area and the value of AD is decreased in the case of a thick area.
In the control method the target beat-up distance is altered in the sense of a lengthening or shortening in order to avoid starting marks, for example thick and/or thin areas, so that fabric, for example terry or smooth fabric, is produced with a weft density in accordance with the program. | A method for weaving blemish-free smooth and terry fabric on a loom following a stoppage of the loom after it has woven a fabric fell which terminates in a last weft thread. The loom has a driven reed which reciprocates during normal weaving towards and away from the fell over a predetermined beat-up distance to successively position additional weft threads at predetermined target positions which assure a uniform, blemish-free fabric. Following a loom stoppage, the next weft yarn, for smooth fabric, and a plurality of next weft yarns, for terry fabric, are moved towards the last weft yarn over a compensated beat-up distance which is different from the predetermined beat-up distance to thereby position the next weft yarn at the desired target position relative to the least weft yarn of the fell to avoid the formation of fabric blemishes. Thereafter the reed is again moved over the predetermined beat-up distance during subsequent picks of the loom. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority of Korean Patent Application Number 10-2012-0124112 filed Nov. 5, 2012, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to an automatic transmission for a vehicle. More particularly, the present invention relates to a planetary gear train of an automatic transmission for a vehicle that can improve mountability by reducing a length thereof and reduce fuel consumption by improving power delivery performance.
[0004] 2. Description of Related Art
[0005] Recently, vehicle makers direct all their strength to improve fuel economy due to worldwide high oil prices and strengthen of exhaust gas regulations.
[0006] Improvement of fuel economy may be achieved by multi-shift mechanism realizing greater number of shift speeds in an automatic transmission. Typically, a planetary gear train is realized by combining a plurality of planetary gear sets and friction elements.
[0007] It is well known that when a planetary gear train realizes a greater number of shift speeds, speed ratios of the planetary gear train can be more optimally designed, and therefore a vehicle can have economical fuel mileage and better performance. For that reason, the planetary gear train that is able to realize more shift speeds is under continuous investigation.
[0008] a different operating mechanism according to a connection between rotation elements (i.e., sun gear, planet carrier, and ring gear). In addition, the planetary gear train has different features such a durability, power delivery efficiency, and size depend on the layout thereof. Therefore, designs for a combining structure of a gear train are also under continuous investigation.
[0009] If the number of shift-speeds, however, increases, the number of components in the automatic transmission also increases. Therefore, mountability, cost, weight and power delivery efficiency may be deteriorated.
[0010] Particularly, since the planetary gear train having a number of components is hard to be mounted in a front wheel drive vehicle, researches for minimizing the number of components have been developed.
[0011] The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY
[0012] Various aspects of the present invention provide for a planetary gear train of an automatic transmission for a vehicle having advantages of improving mountability by shortening a length thereof and reducing fuel consumption by improving power delivery performance as a consequence of achieving eight forward speeds and one reverse speed having excellent operating condition of frictional elements and step ratios by combining three planetary gear sets separately disposed on a first shaft and a second shaft, three externally-meshing gears, and five frictional elements.
[0013] Various aspects of the present invention provide for a planetary gear train of an automatic transmission including: a first shaft receiving torque of an engine; a second shaft disposed in parallel with the first shaft; a first planetary gear set disposed on the first shaft, and including a first sun gear operated as an output element or a fixed element, a first planet carrier selectively operated as an output element, and a first ring gear directly connected to the first shaft and always operated as an input element as rotation elements thereof; a second planetary gear set disposed on the second shaft, and including a second sun gear connected to the first planet carrier through an externally-meshed gear, a second planet carrier, and a second ring gear selectively connected to the first planet carrier and the first ring gear through externally-meshed gears as rotation elements thereof; a third planetary gear set disposed on the second shaft, and including a third sun gear connected to the second ring gear, a third planet carrier selectively connected to the second planet carrier and directly connected to an output gear so as to be operated as an output element, and a third ring gear selectively connected to the first sun gear through an externally-meshed gear as rotation elements thereof; three transfer gears forming the externally-meshed gears; and frictional elements selectively interconnecting the rotation elements of the first, second, and third planetary gear sets or selectively connecting the rotation element to a transmission housing.
[0014] The first planetary gear set may be a double pinion planetary gear set, and the second and third planetary gear sets may be single pinion planetary gear sets.
[0015] The three transfer gears may include: a first transfer gear connecting the first ring gear to the second ring gear; a second transfer gear connecting the first planet carrier directly to the second sun gear and selectively to the second ring gear; and a third transfer gear selectively connecting the first sun gear to the third ring gear.
[0016] The frictional elements may include: a first brake disposed between the first sun gear and the transmission housing; a first clutch disposed between the first sun gear and the third transfer gear; a second clutch disposed between the second transfer gear and the second ring gear; a third clutch disposed between the second planet carrier and the third planet carrier; and a fourth clutch disposed between the first transfer gear and the second ring gear.
[0017] The first brake and the first and fourth clutches may be operated at a first forward speed, the first brake and the first and second clutches may be operated at a second forward speed, the first, second, and fourth clutches may be operated at a third forward speed, the first, second, and third clutches may be operated at a fourth forward speed, the first, third, and fourth clutches may be operated at a fifth forward speed, the second, third, and fourth clutches may be operated at a sixth forward speed, the first brake and the third and fourth clutches may be operated at a seventh forward speed, the first brake and the second and third clutches may be operated at an eighth forward speed, and the first brake and the first and third clutches may be operated at a reverse speed.
[0018] Various aspects of the present invention provide for a planetary gear train of an automatic transmission for a vehicle including: a first shaft receiving torque of an engine; a second shaft disposed in parallel with the first shaft; a first planetary gear set disposed on the first shaft, and including a first sun gear operated as an output element or a fixed element, a first planet carrier selectively operated as an output element, and a first ring gear directly connected to the first shaft and always operated as an input element; a second planetary gear set disposed on the second shaft, and including a second sun gear connected to the first planet carrier, a second planet carrier, and a second ring gear selectively connected to the first planet carrier and the first ring gear; a third planetary gear set disposed on the second shaft, and including a third sun gear connected to the second ring gear, a third planet carrier selectively connected to the second planet carrier and directly connected to an output gear so as to be operated as an output element, and a third ring gear selectively connected to the first sun gear; a first transfer gear connecting the first ring gear to the second ring gear; a second transfer gear connecting the first planet carrier directly to the second sun gear and selectively to the second ring gear; a third transfer gear selectively connecting the first sun gear to the third ring gear; a first brake disposed between the first sun gear and the transmission housing; a first clutch disposed between the first sun gear and the third transfer gear; a second clutch disposed between the second transfer gear and the second ring gear; a third clutch disposed between the second planet carrier and the third planet carrier; and a fourth clutch disposed between the first transfer gear and the second ring gear.
[0019] The first planetary gear set may be a double pinion planetary gear set, and the second and third planetary gear sets may be single pinion planetary gear sets.
[0020] The first brake and the first and fourth clutches may be operated at a first forward speed, the first brake and the first and second clutches may be operated at a second forward speed, the first, second, and fourth clutches may be operated at a third forward speed, the first, second, and third clutches may be operated at a fourth forward speed, the first, third, and fourth clutches may be operated at a fifth forward speed, the second, third, and fourth clutches may be operated at a sixth forward speed, the first brake and the third and fourth clutches may be operated at a seventh forward speed, the first brake and the second and third clutches may be operated at an eighth forward speed, and the first brake and the first and third clutches may be operated at a reverse speed.
[0021] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic diagram of an exemplary planetary gear train according to the present invention.
[0023] FIG. 2 is an operational chart of friction members at each shift-speed applied to an exemplary planetary gear train according to the present invention.
[0024] FIG. 3A is a lever diagram of an exemplary planetary gear train at the first forward speed according to the present invention.
[0025] FIG. 3B is a lever diagram of an exemplary planetary gear train at the second forward speed according to the present invention.
[0026] FIG. 3C is a lever diagram of an exemplary planetary gear train at the third forward speed according to the present invention.
[0027] FIG. 3D is a lever diagram of an exemplary planetary gear train at the fourth forward speed according to the present invention.
[0028] FIG. 3E is a lever diagram of an exemplary planetary gear train at the fifth forward speed according to the present invention.
[0029] FIG. 3F is a lever diagram of an exemplary planetary gear train at the sixth forward speed according to the present invention.
[0030] FIG. 3G is a lever diagram of an exemplary planetary gear train at the seventh forward speed according to the present invention.
[0031] FIG. 3H is a lever diagram of an exemplary planetary gear train at the eighth forward speed according to the present invention.
[0032] FIG. 3I is a lever diagram of an exemplary planetary gear train at a reverse speed according to the present invention.
DETAILED DESCRIPTION
[0033] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0034] Description of components that are not necessary for explaining the various embodiments will be omitted, and the same constituent elements are denoted by the same reference numerals in this specification.
[0035] In the detailed description, ordinal numbers are used for distinguishing constituent elements having the same terms, and have no specific meanings.
[0036] FIG. 1 is a schematic diagram of a planetary gear train according to various embodiments of the present invention.
[0037] Referring to FIG. 1 , a planetary gear train according to various embodiments of the present invention includes first, second, and third planetary gear sets PG 1 , PG 2 , and PG 3 , five frictional elements B 1 , C 1 , C 2 , C 3 , and C 4 , and three transfer gears TF 1 , TF 2 , and TF 3 .
[0038] The first planetary gear set PG 1 is disposed on a first shaft IS 1 , and the second and third planetary gear sets PG 2 and PG 3 are disposed on a second shaft IS 2 disposed apart from and in parallel with the first shaft IS 1 .
[0039] Therefore, torque input from the first shaft IS 1 is transmitted to the second and third planetary gear sets PG 2 and PG 3 through the first planetary gear set PG 1 , is converted into eight forward speeds and one reverse speed by operations of the first, second, and third planetary gear sets PG 1 , PG 2 , and PG 3 , and is then output through an output gear OG.
[0040] The first planetary gear set PG 1 is a double pinion planetary gear set, and having a first sun gear S 1 , a first ring gear R 1 , and a first planet carrier PC 1 rotatably supporting a first pinion P 1 engaged with the first sun gear S 1 and the first ring gear R 1 as rotation elements thereof.
[0041] The second planetary gear set PG 2 is a single pinion planetary gear set, and having a second sun gear S 2 , a second ring gear R 2 , and a second planet carrier PC 2 rotatably supporting a second pinion P 2 engaged with the second sun gear S 2 and the second ring gear R 2 as rotation elements thereof.
[0042] The third planetary gear set PG 3 is a single pinion planetary gear set, and having a third sun gear S 3 , a third ring gear R 3 , and a third planet carrier PC 3 rotatably supporting a third pinion P 3 engaged with the third sun gear S 3 and the third ring gear R 3 as rotation elements thereof.
[0043] The first ring gear R 1 is directly connected to the first shaft IS 1 and is always operated as an input element.
[0044] In addition, the second ring gear R 2 is connected to the third sun gear S 3 through the second shaft IS 2 , the second planet carrier PC 2 is selectively connected to the third planet carrier PC 3 , and the third planet carrier PC 3 is directly connected to an output gear OG and is always operated as an output element.
[0045] It is illustrated, but is not limited, that the second ring gear R 2 is connected to the third sun gear S 3 through the second shaft IS 2 . That is, the second ring gear R 2 may be connected to the third sun gear S 3 through a rotating member disposed on an external circumferential portion of the second shaft IS 2 without rotational interference between the rotating member and the second shaft IS 2 .
[0046] In addition, the first ring gear R 1 as well as the first shaft IS 1 is selectively connected to the second ring gear R 2 through an externally-meshed gear, the first sun gear S 1 is selectively connected to the third ring gear R 3 through an externally-meshed gear and is selectively connected to a transmission housing H, and the first planet carrier PCI is connected to the second sun gear S 2 and is selectively connected to the second ring gear R 2 through an externally-meshed gear.
[0047] The first, second, and third transfer gears TF 1 , TF 2 , and TF 3 , being the externally-meshed gears, may be helical gears and respectively have first, second, and third transfer drive gears TF 1 a , TF 2 a , and TF 3 a and first, second, and third transfer driven gears TF 1 b , TF 2 b , and TF 3 b externally meshed with each other.
[0048] The first transfer gear TF 1 includes the first transfer drive gear TF 1 a directly connected to the first ring gear R 1 and the first transfer driven gear TF 1 b selectively connected to the second ring gear R 2 .
[0049] Therefore, the first transfer gear TF 1 selectively connects the first ring gear R 1 to the second ring gear R 2 .
[0050] The second transfer gear TF 2 includes the second transfer drive gear TF 2 a directly connected to the first planet carrier PC 1 and the second transfer driven gear TF 2 b directly connected to the second sun gear S 2 and selectively connected to the second ring gear R 2 .
[0051] Therefore, the second transfer gear TF 2 connects the first planet carrier PC 1 directly to the second sun gear S 2 and selectively to the second ring gear R 2 .
[0052] The third transfer gear TF 3 includes the third transfer drive gear TF 3 a selectively connected to the first sun gear S 1 and the third transfer driven gear TF 3 b directly connected to the third ring gear R 3 .
[0053] Therefore, the third transfer gear TF 3 selectively connects the first sun gear S 1 to the third ring gear R 3 .
[0054] The rotation elements connected to each other by the first, second, and third transfer gears TF 1 , TF 2 , and TF 3 are rotated in opposite direction to each other. Gear ratios of the first, second, and third transfer gears TF 1 , TF 2 , and TF 3 are set according to speed ratios demanded at shift-speeds.
[0055] Arrangements of the frictional elements B 1 , C 1 , C 2 , C 3 , and C 4 will be described in detail.
[0056] The first brake B 1 is disposed between the first sun gear S 1 and the transmission housing H.
[0057] The first clutch C 1 is disposed between the first sun gear S 1 and the third transfer gear TF 3 .
[0058] The second clutch C 2 is disposed between the second transfer gear TF 2 and the second ring gear R 2 .
[0059] The third clutch C 3 is disposed between the second planet carrier PC 2 and the third planet carrier PC 3 .
[0060] The fourth clutch C 4 is disposed between the first transfer gear TF 1 and the second ring gear R 2 .
[0061] The frictional elements consisting of the first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and the first brake B 1 are conventional multi-plate friction elements of wet type that are operated by hydraulic pressure.
[0062] FIG. 2 is an operational chart of friction members at each shift-speed applied to a planetary gear train according to various embodiments of the present invention.
[0063] As shown in FIG. 2 , three frictional elements are operated at each shift-speed in the planetary gear train according to various embodiments of the present invention.
[0064] The first brake B 1 and the first and fourth clutches C 1 and C 4 are operated at a first forward speed 1 ST .
[0065] The first brake B 1 and the first and second clutches C 1 and C 2 are operated at a second forward speed 2 ND .
[0066] The first, second, and fourth clutches C 1 , C 2 , and C 4 are operated at a third forward speed 3 RD .
[0067] The first, second, and third clutches C 1 , C 2 , and C 3 are operated at a fourth forward speed 4 TH .
[0068] The first, third, and fourth clutches C 1 , C 3 , and C 4 are operated at a fifth forward speed 5 TH .
[0069] The second, third, and fourth clutches C 2 , C 3 , and C 4 are operated at a sixth forward speed 6 TH .
[0070] The first brake B 1 and the third and fourth clutches C 3 and C 4 are operated at a seventh forward speed 7 TH .
[0071] The first brake B 1 and the second and third clutches C 2 and C 3 are operated at an eighth forward speed 8 TH .
[0072] The first brake B 1 and the first and third clutches C 1 and C 3 are operated at a reverse speed Rev.
[0073] FIG. 3A to FIG. 3I are lever diagrams of the planetary gear train at each shift-speed according to various embodiments of the present invention, and illustrate shift processes of the planetary gear train according to the various embodiments of the present invention by lever analysis method.
[0074] Referring to FIG. 3A to FIG. 3I , three vertical lines of the first planetary gear set PG 1 are set as the first sun gear S 1 being a first rotation element N 1 , the first ring gear R 1 being a second rotation element N 2 , and the first planet carrier PCI being a third rotation element N 3 from the left to the right.
[0075] In addition, the second and third planetary gear sets PG 2 and PG 3 are operated as a selective compound planetary gear set according to operation of the third clutch C 3 . Four vertical lines of the second and third planetary gear sets PG 2 and PG 3 are set as the second sun gear S 2 being a fourth rotation element N 4 , the third ring gear R 3 being a fifth rotation element N 5 , the third planet carrier PC 3 or the second planet carrier PC 2 and the third planet carrier PC 3 being a sixth rotation element N 6 , and the second ring gear R 2 and the third sun gear S 3 being a seventh rotation element N 7 from the left to the right.
[0076] Since the third clutch C 3 is not operated from the first forward speed to the third forward speed, the third planet carrier PC 3 is set as the sixth rotation element N 6 . Since the third clutch C 3 is operated from the fourth forward speed to the eighth forward speed and at the reverse speed, however, the second and third planet carriers PC 2 and PC 3 are set as the sixth rotation element N 6 .
[0077] In addition, a middle horizontal line represents a rotation speed of “0”, an upper horizontal line represents a rotation speed of “1.0”, and a lower horizontal line represents a rotation speed of “−1.0”.
[0078] “−” means that rotational elements is rotated in an opposite direction of a rotational direction of the engine. It is because the rotation elements are externally meshed with each other through the first, second, and third transfer gears TF 1 , TF 2 , and TF 3 without an idling gear.
[0079] In addition, the rotation speed of “1.0” represents the same rotational speed as the first shaft IS 1 which is an input shaft. Distances between the vertical lines of the first, second, and third planetary gear sets PG 1 , PG 2 , and PG 3 are set according to each gear ratio (teeth number of a sun gear/teeth number of a ring gear).
[0080] Hereinafter, referring to FIG. 2 and FIG. 3A to FIG. 3I , the shift processes of the planetary gear train according to various embodiments of the present invention will be described in detail.
[0081] First Forward Speed
[0082] Referring to FIG. 2 , the first brake B 1 and the first and fourth clutches C 1 and C 4 are operated at the first forward speed 1 ST .
[0083] As shown in FIG. 3A , a rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , and the first rotation element N 1 and the fifth rotation element N 5 are operated as fixed elements by operation of the first brake B 1 and the first clutch C 1 .
[0084] Therefore, a rotation speed of the third rotation element N 3 is decreased according to the gear ratio of the second transfer gear TF 2 and is then input to the fourth rotation element N 4 as an inverse rotation speed, and the rotation speed of the first shaft IS 1 is converted according to the gear ratio of the first transfer gear TF 1 by operation of the fourth clutch C 4 and is then input to the seventh rotation element N 7 as an inverse rotation speed.
[0085] Therefore, the rotation elements of the third planetary gear set PG 3 form a first shift line SP 1 and D 1 is output through the sixth rotation element N 6 that is the output element.
[0086] At this time, the rotation elements of the second planetary gear set PG 2 form a thick dotted line T, but it does not have any effect on shifting.
[0087] Second Forward Speed
[0088] The fourth clutch C 4 that was operated at the first forward speed 1 ST is released and the second clutch C 2 is operated at the second forward speed 2 ND .
[0089] As shown in FIG. 3B , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , and the first rotation element N 1 and the fifth rotation element N 5 are operated as fixed elements by operation of the first brake B 1 and the first clutch C 1 .
[0090] Therefore, the rotation speed of the third rotation element N 3 is decreased according to the gear ratio of the second transfer gear TF 2 and is then input to the fourth rotation element N 4 as an inverse rotation speed, and the second planetary gear set PG 2 becomes a direct-coupling state by operation of the second clutch C 2 .
[0091] Therefore, the rotation elements of the third planetary gear set PG 3 form a second shift line SP 2 and D 2 is output through the sixth rotation element N 6 that is the output element.
[0092] At this time, the rotation elements of the second planetary gear set PG 2 form a thick dotted line T, but it does not have any effect on shifting.
[0093] Third Forward Speed
[0094] The first brake B 1 that was operated at the second forward speed 2 ND is released and the fourth clutch C 4 is operated at the third forward speed 3 RD .
[0095] As shown in FIG. 3C , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 , the first rotation element N 1 is connected to the fifth rotation element N 5 through the third transfer gear TF 3 by operation of the first clutch C 1 , and the second rotation element N 2 is connected to the seventh rotation element N 7 through the first transfer gear TF 1 by operation of the fourth clutch C 4 .
[0096] Therefore, the rotation elements of the third planetary gear set PG 3 form a third shift line SP 3 and D 3 is output through the sixth rotation element N 6 that is the output element.
[0097] At this time, the rotation elements of the second planetary gear set PG 2 form a thick dotted line T, but it does not have any effect on shifting.
[0098] Fourth Forward Speed
[0099] The fourth clutch C 4 that was operated at the third forward speed 3 RD is released and the third clutch C 3 is operated at the fourth forward speed 4 TH .
[0100] As shown in FIG. 3D , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 , the first rotation element N 1 is connected to the fifth rotation element N 5 through the third transfer gear TF 3 by operation of the first clutch C 1 , and the third rotation element N 3 is connected to the seventh rotation element N 7 through the second transfer gear TF 2 by operation of the second clutch C 2 .
[0101] Therefore, the second and third planetary gear sets PC 2 and PC 3 become direct-coupling state, the rotation elements of the second and third planetary gear sets PC 2 and PC 3 form a fourth shift line SP 4 , and D 4 is output through the sixth rotation element N 6 that is the output element.
[0102] Fifth Forward Speed
[0103] The second clutch C 2 that was operated at the fourth forward speed 4 TH is released and the fourth clutch C 4 is operated at the fifth forward speed 5 TH .
[0104] As shown in FIG. 3E , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 and is input to the seventh rotation element N 7 through the first transfer gear TF 1 by operation of the fourth clutch C 4 .
[0105] In addition, the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 , and the first rotation element N 1 is connected to the fifth rotation element N 5 through the third transfer gear TF 3 by operation of the first clutch C 1 .
[0106] Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a fifth shift line SP 5 and D 5 is output through the sixth rotation element N 6 that is the output element.
[0107] Sixth Forward Speed
[0108] The first clutch C 1 that was operated at the fifth forward speed 5 TH is released and the second clutch C 2 is operated at the sixth forward speed 6 TH .
[0109] As shown in FIG. 3F , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 and is input to the seventh rotation element N 7 through the first transfer gear TF 1 by operation of the fourth clutch C 4 .
[0110] In addition, the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 and is connected to the seventh rotation element N 7 by operation of the second clutch C 2 .
[0111] Therefore, the second and third planetary gear sets PC 2 and PC 3 become direct-coupling state, the rotation elements of the second and third planetary gear sets PC 2 and PC 3 form a sixth shift line SP 6 , and D 6 is output through the sixth rotation element N 6 that is the output element.
[0112] Seventh Forward Speed
[0113] The second clutch C 2 that was operated at the sixth forward speed 6 TH is released and the first brake B 1 is operated at the seventh forward speed 7 TH .
[0114] As shown in FIG. 3G , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 and is input to the seventh rotation element N 7 through the first transfer gear TF 1 by operation of the fourth clutch C 4 , and the first rotation element N 1 is operated as a fixed element by operation of the first brake B 1 .
[0115] In addition, the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 .
[0116] Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a seventh shift line SP 7 and D 7 is output through the sixth rotation element N 6 that is the output element.
[0117] Eighth Forward Speed
[0118] The fourth clutch C 4 that was operated at the seventh forward speed 7 TH is released and the second clutch C 2 is operated at the eighth forward speed 8 TH .
[0119] As shown in FIG. 3H , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , and the first rotation element N 1 is operated as a fixed element by operation of the first brake B 1 .
[0120] In addition, the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 and is connected to the seventh rotation element N 7 through the second transfer gear TF 2 by operation of the second clutch C 2 .
[0121] Therefore, the second and third planetary gear sets PC 2 and PC 3 become direct-coupling state, the rotation elements of the second and third planetary gear sets PC 2 and PC 3 form an eighth shift line SP 8 , and D 8 is output through the sixth rotation element N 6 that is the output element.
[0122] Reverse Speed
[0123] As shown in FIG. 2 , the first brake B 1 and the first and third clutches C 1 and C 3 are operated at the reverse speed Rev.
[0124] As shown in FIG. 3I , the rotation speed of the first shaft IS 1 is input to the second rotation element N 2 , and the first rotation element N 1 and the fifth rotation element N 5 are operated as fixed elements by operation of the first brake B 1 and the first clutch C 1 .
[0125] In addition, the third rotation element N 3 is connected to the fourth rotation element N 4 through the second transfer gear TF 2 .
[0126] Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a reverse shift line RS, and REV is output through the sixth rotation element N 6 that is the output element.
[0127] Since three planetary gear sets are separately disposed on the first shaft and the second shaft disposed apart from and in parallel with each other in the planetary gear train according to various embodiments of the present invention, a length thereof may be reduced and mountability may be improved.
[0128] In addition, optimum gear ratios may be set due to ease of changing gear ratios by using three external-meshing gears as well as the planetary gear sets. Since gear ratios can be changed according to target performance, starting performance may be improved. Therefore, a start-up clutch instead of a torque converter may be used.
[0129] Since three frictional elements are operated at each shift-speed, non-operated frictional element may be minimized and drag torque may be reduced. In addition, fuel consumption may be reduced by increasing power delivery efficiency.
[0130] In addition, since torque load of each frictional element can be reduced, compact design is possible.
[0131] For convenience in explanation and accurate definition in the appended claims, the ten is upper or lower, front, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0132] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A planetary gear train including: a first planetary gear set on a first shaft including a first sun gear operated as an output or fixed element, a first planet carrier operable as an output element, and a first ring gear operated as an input element; a second planetary gear set on a second shaft including a second sun gear connected to the first planet carrier, a second planet carrier, and a second ring gear engaging the first planet carrier and the first ring gear; a third planetary gear set on the second shaft including a third sun gear connected to the second ring gear, a third planet carrier engaging the second planet carrier and connected to an output gear, and a third ring gear engaging the first sun gear; three transfer gears; and frictional elements interconnecting the first, second, and third planetary gear sets and/or connecting a transmission housing. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to high pressure combustors for generating a mixture of steam and combustion gas downhole in an oil well. The mixture is injected into the surrounding oil reservoir to displace heavy oil from the reservoir.
The energy consumption in this process is great. It takes the energy equivalent of one barrel of oil to displace three barrels of oil from the reservoir. There is an incentive to burn the cheapest fuel available, which is usually the heavy crude oil produced from the same reservoir. Heavy oils will not light off and burn without substantial heat. It is simpler to heat air rather than oil, because the weight of air is 14-15 times the weight of oil. Also, heavy oil is not suitable for use in a catalytic heat exchanger, which is part of the present invention, because heavy oil would foul the surface of the heat exchanger. This invention discloses a means for providing heated air for burning heavy oil in the later stages of a multi-stage combustor.
SUMMARY OF THE INVENTION
In this combustor the combustion is built up in stages, with each stage supplying heated air to the following stage. The first stage comprises a catalytic heat exchanger, for preheating incoming air. One side of the exchanger is coated with catalyst. On this side of the exchanger the preheated air burns a clean fuel, such as natural gas or distillate oil, so that heat flows through the metal wall of the exchanger and preheats the incoming air. The heated air leaving the first stage is used to ignite and burn a heavy fuel such as crude oil, which is burned in the second stage and following stages. Thus, the relatively expensive "clean" fuel is used only in the first (catalytic) stage, and the second and following stages can be fueled with cheaper heavy crude oil.
It is an object of the invention to provide a combustor for generating a mixture of steam and combustion gas downhole so that the mixture can be injected directly into the oil reservoir.
It is another object to provide a combustor wherein the combustion is built up in stages so that each stage provides heated air for the following stage.
It is another object to provide a stage combustor wherein the first stage is a catalytic heat exchanger for preheating the incoming air.
It is another object to provide a stage combustor wherein heavy crude oil can be burned in the second stage and following stages.
It is another object to provide a staged combustor wherein only the first stage requires relatively expensive fuel.
Other objects and advantages of the invention will be apparent to persons skilled in the art, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-section of the first stage of the combustor, showing the flow path of air through the catalytic heat exchanger.
FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 1.
FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 3.
FIG. 5 is a schematic flow diagram of one embodiment of the invention, showing three stages of combustion.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 5 is a schematic diagram which illustrates the basic operation of the invention. The three stages of combustion are designated by reference numerals 11, 12 and 13. The structure of first stage 11 is described in detail later in this section. Stages 12 and 13 may be merely an open pipe, or may have more complex structures. As indicated, air, oil and water each at 70° F., are fed to the combustor. The designation of 70° F. is meant to indicate ambient temperature, and is not to be deemed critical. The numbers at the left-hand side of the figure (1440, 100 and 1387) indicate relative amounts by weight. Thus, for 100 pounds of fuel oil, having a net heating value of 18,500 BTUs per pound, one needs 1440 pounds of air to burn all the oil to yield a combustion gas that contains essentially no oxygen. The 1387 pounds of water is just enough to give a final mixture of combustion gas and steam at 500° F. which is suitable for injecting into the oil reservoir. The relative amounts of fuel and air are calculated from heat and mass balances. It is understood, however, that the numbers shown in the figure are for illustrative purposes only, and that the invention can be operated with other ratios, as will be explained below.
For this calculation, the fuel was assumed to be oil, and the same oil was fed to all three stages. The preferred fuel for stages 12 and 13 is crude oil or topped crude. Crude oil should not be fed to stage 11 because it would foul the catalyst. The fuel to stage 11 must be a clean distillate oil or a gas such as methane or natural gas. This substitution will change the flow rates slightly, but not the temperatures.
In the embodiment shown in FIG. 5, air is supplied only to the first combustion stage 11. As illustrated, the air is directed through this combustion stage three times, the air being forced to go back and forth, as shown. It is on the third pass through stage 11 that combustion occurs. The combustion stage 11 is so designed that the combustion therein pre-heats the air which is making a first or second pass through this stage of the combustor. Structural details of the combustor will be given below.
FIG. 5 indicates the temperatures at the input and output ends of each stage of the combustor. These temperatures are the temperatures that will be obtained under the operating conditions given in FIG. 5. However, other sets of temperatures are satisfactory, subject to the requirement that the temperature never become so low as to quench the combustion.
The numbers below each combustion stage in FIG. 5 indicate the relative amounts of oil and water that are fed to each stage. Thus, the 100 pounds of oil is divided as 38.1 pounds to the first stage, 27.6 pounds to the second stage, and 34.3 pounds to the third stage. There are 246 pounds of water fed between the first and second stages, 306 pounds between the second and third stages, and 835 pounds after the third stage.
The temperature leaving each stage is shown as 1830° F., which is high enough to insure complete combustion. The temperatures at the input ends of each stage must be high enough to insure that the fuel will ignite and burn. Also, the temperature entering successive stages should increase (note that FIG. 5 shows the input temperatures for stages 11, 12 and 13 to be 700°-800° F., and 1000° F., an increase from one stage to the next). This increase in temperature is to compensate for the lower concentration of oxygen after each combustion stage.
FIG. 1 is a vertical section through the inlet to the preheating stage, which shows, in more detail, a possible design for first stage 11. Air enters through duct 100, defined by duct wall 24, in the direction of arrow 80, and returns through the annular space between walls 20 and 21, as indicated by arrows 81. The preheated air then flows through the annular space between duct wall 24 and wall 21 as indicated by arrows 82. Fuel enters through duct 26, donut ring 27, and nozzles 28, and mixes with the preheated air. Reference numeral 25 designates the upper extremity of a set of involute fins, to be described below, and the space between nozzles 28 and the upper extremity of fins 25 is for mixing the fuel and the air. Duct 29 is one of several that carries fuel or water to the successive combustion stages.
The mixture of combustion gas and steam that emerges from the combustor (along the path of arrows 82) is forced into the sand formation 30 of the oil reservoir. The oil well casing 31 is cemented into the formation in a conventional manner, and a pressure seal between the casing and the combustor is formed by packing 32.
FIG. 2 is a section across the bore of the catalytic heat exchanger in first stage 11. The exchanger has a double wall, 20 and 21, separated by a corrugated fin 22, to increase the heat transfer to air flowing between walls 20 and 21. The corrugated fin 22 oscillates between the walls 20 and 21 of the annulus. There is shown central duct wall 24. Air flows through duct 100 (as indicated by arrows 80 in FIG. 1) and returns through the annular space between walls 20 and 21. Curved fins 25 extend from wall 21 to duct wall 24. The curve of the fins is the involute of a circle. Adjacent fins are equidistant over their entire arc, which is the reason for using the involute. Thus, the annulus between wall 21 and duct wall 24 is filled with a uniform density of surface for heat transfer and combustion. The inside of wall 21, the outside of duct wall 24, and all of the surface of fins 25 are coated with catalyst. The inside of duct wall 24 is bare, i.e. devoid of catalyst. Heat generated on the surface of a fin 25 is conducted along the arc of the fin to wall 21 or to duct wall 24.
Some of the channels formed by corrugated fin 22 can serve as ducts for the fuel and the water going to the successive stages of combustion.
FIG. 3, a cross-sectional view taken along the line 3--3 of FIG. 1, illustrates the structure of the first combustion stage, near its output end. Well casing 31 is shown, as well as walls 20 and 21, together with duct 100 defined by duct wall 24. The figure also illustrates a plurality of hollow spokes 103 which connect duct 100 with the space between walls 20 and 21. As is also shown in FIG. 1, spokes 103 provide a path for air to flow out of duct 100 and back through the space between walls 20 and 21.
Spokes 103 are, in this embodiment, of a streamlined cross-section, as illustrated in FIG. 4, taken along the line 4--4 of FIG. 3.
The fuel-air mixture in the first combustion stage can be ignited by glow plug 33. Alternatively, the combustion can be started by preceding the gaseous or oil fuel with a hypergolic fuel that ignites spontaneously upon contact with air. Either way, the first combustion can be a flame that anchors itself to the donut ring 27. The flame is allowed to burn long enough to heat the catalytic surface sufficiently for it to sustain catalytic combustion. Then the flow of fuel is momentarily cut off to extinguish the flame. Next the flow of fuel is resumed, though of course now there is no flame, and the combustion proceeds on the catalytic surface of the air preheater in first stage 11.
When the feed to the first stage has been set at 38.1 pounds of oil and 1440 pounds of air, as shown in FIG. 5, the temperature leaving the first stage will level out at 1830° F., and the temperature leaving the third stage 13 would reach 1830° F., even though combustion in the last two stages has not yet started. The injection of water after the third stage is started, to quench the final temperature to 500° F. Next, oil and water are injected ahead of second stage 12, gradually increasing to the rates shown in FIG. 1. Simultaneously, the amount of water injected after third stage 13 is increased to hold the final temperature at 500° F. The third stage 13 is brought on stream in the same way. Now all of the temperatures and flow rates are as shown in FIG. 1.
It is understood that one can "set" the feed to a given stage to be a specified amount of fuel, water etc., either by actually measuring the flow, or by an indirect means. A practical indirect means is to monitor the temperature at both the input and output side of a combustion stage, and to vary the flow rates of fuel and water (or, in the case of the first stage, fuel and air) until the desired temperatures are achieved. When the desired input and output temperatures are observed, one can infer that the flow rates are correct.
In FIG. 5, the final temperature of 500° F. is fixed by the two ratios, air/oil and water/oil. All other temperatures can be varied without changing these ratios. To raise the temperature from the first stage, one would burn more of the oil in the first stage. To raise the temperatures from the second and third stages, one would inject less water ahead of these stages, and inject the extra water after the third stage.
The temperature entering the second stage, in the embodiment shown in FIG. 5, is calculated by heat balance, from mixing 27.6 pounds of oil and 246 pounds of water, both at 70° F., with 1478 pounds of combustion gas from the first stage. This calculated 930° F. is the temperature that would exist if mixing were completed before any of the 27.6 pounds of oil were burned. It is the lowest temperature that can exist. The actual temperature will likely be higher because some burning takes place simultaneously with mixing. The temperature must be kept high enough to insure that there is no possibility of extinguishing the combustion. This is the criterion which is most important in designing combustors having different numbers of stages. If the feeds to the second and third stages were combined and fed to a single combined stage, the calculated minimum temperature entering that combined stage would be only about 100° F. If burning did not proceed simultaneously with mixing, the combustion would certainly be extinguished. But if the combined feeds to the second and third stages were divided among more than two stages, the calculated minimum temperatures entering these stages would be higher than the temperatures in FIG. 5, but the outlet temperatures would remain at 1830° F.
There are some simple combustors that comprise only the first stage in FIG. 5. For example, one can burn 38.1 pounds of air with 1440 pounds of air, and quench the combustion gas with 457 pounds of water. The resulting mixture is at 500° F., which is right for injecting into the oil reservoir. The mixture contains about 12% oxygen, however. In the preferred embodiment, the mixture for injection contains no oxygen, which is why the additional stages were included in FIG. 5.
In a second example, one can substitute 34.5 pounds of methane gas for the 38.1 pounds of oil. The temperature from the first stage remains at 1830° F., and the other temperatures and flow rates are almost unchanged. This amount of methane constitutes 4.2 mol% in the methane-air mixture, which is below the flammability limit of 5.3%. (The flammability limit is that mol% of methane, or other combustible gas, below which a flame will not travel through the mixture.) Thus, the air and methane could be mixed at ground level and piped downhole through a single pipe. The problem of mixing air and fuel ahead of the first stage is eliminated. There is no lower limit to the concentration of combustible that can be burned over a catalyst, and this is the essence of this example.
In a third example, one can burn a mixture that contains, say, 4.2% methane and 8.4% oxygen, the remainder being noncombustible gases such as nitrogen or carbon dioxide. What is important is that the methane content is below the flammability limit, and that the oxygen content is just sufficient to burn the methane completely, so there is no oxygen in the combustion gas. One analogous mixture would contain 2.0% propane and 10.0% oxygen. The gases are mixed at ground level and piped downhole through a single pipe. The problem of mixing air and fuel downhole is eliminated completely. The oxygen free combustion gas is quenched with water and injected into the oil reservoir.
In FIG. 5, the oil and water are injected into stages 12 and 13 in separate streams. The oil and water can as well be combined into an emulsion and fed as a single stream. Also in FIG. 5, all of the air is fed to the first stage. It is quite possible to bypass some of the air to the later stages of combustion.
As stated above, the number of stages of combustion can be varied, as long as operating conditions are chosen so as not to quench the combustion. Other design details are variable, such as the number of passes made by the air through the first stage. These and other modifications are to be deemed within the spirit and scope of the following claims. | A combustor for generating a mixture of steam and combustion gas is located downhole in an oil well, so that the mixture can be injected directly into the reservoir, to displace heavy oil from the reservoir. The combustion is built up in stages, with each stage supplying hot air to the following stage. The first stage comprises a catalytic heat exchanger, which preheats the incoming air. One side of the exchanger is coated with catalyst. On this side of the exchanger the preheated air burns a clean fuel, so that heat flows through the metal wall of the exchanger to preheat the incoming air. The heated air from the first stage is used to ignite and burn a heavy fuel such as crude oil, which is burned in the second stage and following stages. | 8 |
FIELD OF THE INVENTION
[0001] The invention relates to extruded products made of aluminum Al—Mn alloy (series 3000 according to the nomenclature of the Aluminum Association) with improved mechanical resistance, especially tubes designed in particular for piping or heat exchangers for automotive engineering.
BACKGROUND OF RELATED ART
[0002] Today, three vehicles out of four sold in France have air-conditioning. In 2020, nine vehicles out of ten will be air-conditioned. Automobile air-conditioning has a considerable impact on climate change for two main reasons. The first is the extra fuel consumed. This depends greatly on the type of vehicle and how it is used, but is estimated at an average of 7% of fuel consumed. The second is related to losses of refrigerant. The fluid currently used today (HFC-R134a, CH2 FCF3) has an impact on the greenhouse effect approximately one thousand four hundred times greater than the equivalent mass of carbon dioxide (CO2) and it is usually accepted that each vehicle loses a third of the contents (approximately 900 g) of the cooling circuit each year.
[0003] Many studies are currently examining the replacement of hydrofluorocarbons (HFC) with CO2 for air-conditioning systems. Even though CO2 is a greenhouse gas, its impact is much lower than that of HFCs, which may make it possible to decrease the noxiousness of emissions related to leaks.
[0004] An air-conditioning system running on CO2 as a refrigerating gas is based on the compression and expansion of gas. A compressor compresses the CO2 at high pressure and this then moves into a gas cooler (usually called condenser, but in which condensation does not occur when the refrigerant is CO2), then into an internal heat exchanger (which allows heat exchange with the low pressure zone). The CO2, still as a gas then moves into a pressure reducer from which comes a liquid which cools the passenger compartment by passing through an evaporator. The low pressure gas then accumulates before circulating inside the internal heat exchanger and returning to the compressor for a new cycle. Extruded products made of aluminum can be used to manufacture the heat exchangers (gas cooler and evaporator) and/or to produce the piping allowing the refrigerant to circulate between the various parts of the cooling circuit.
[0005] The use of CO2 as refrigerant is made difficult because of the pressure at which it must be used. The critical temperature of CO2 is lower than that of HFC-134a and its critical pressure is higher, which means that the air-conditioning system has to run at to higher pressures and temperatures than those currently in use, whether in the high pressure part or the low pressure part of the circuit. The materials used in the air-conditioning circuit must therefore be more hard-wearing than currently used materials, while maintaining performance levels that are at least equivalent in terms of manufacture, shaping, assembly and corrosion resistance. For good refrigerating efficiency, CO2 therefore needs to be compressed with high pressures of about 100 to 200 bar. Because of this, in order for CO2 to be used as a refrigerant, the piping must withstand an operating pressure of 200 bar for high temperatures of 130-170° C., which is high compared to current conditions: about 5 bar at 60° C.
[0006] Alloys have been proposed for the production of flat tubes for heat exchangers (gas coolers and evaporators) of air-conditioning systems using CO2 as refrigerating gas. JP 2005-068557 describes an alloy composed as follows (% by weight) Mn: 0.8−2, Cu: 0.22−0.6, Ti: 0.01−0.2, Fe: 0.01−0.4, Zn≦0.2, Sn≦0.018, In≦0.02.
[0007] JP 2007-070699 describes an alloy composed as follows (% by weight) Si: 0.31−0.7, Fe: 0.3−0.6, Mn: 0.01−0.4, and as an option Ti 0.01−0.3, Zr 0.05−0.3, Cr 0.05−0.3.
[0008] These alloys do not seem to make it possible to reach some of the required performance levels in terms of hardness, in particular for tubes designed for piping. In addition, several alloys of the 3XXX series are known for the production of tubes designed for air-conditioning systems using conventional refrigerating gases.
[0009] Patent application WO 97/46726 by Reynolds Metals relates to an alloy, known as X3030, composed as follows (% by weight): Mn: 0.1−0.5, Cu<0.03, Mg<0.01, Zn: 0.06−1.0, Si: 0.05−0.12, Fe<0.50, Ti: 0.03−0.30, Cr<0.50, the rest aluminum. Adding Zn and Ti contributes to improved corrosion resistance. Cr is maintained preferably below 0.20%.
[0010] Patent application WO 99/18250 by the same company relates to an alloy designated as X3020 with better formability than X3030 by the addition of Mg (up to 1%) and
[0011] Zr (up to 0.30%). Cr is maintained preferably below 0.02%, or even 0.01%; Ti is maintained preferably above 0.12% and Zn above 0.1%.
[0012] Patent application WO 00/50656 by Norsk Hydro relates to an alloy composed as follows: Si: 0.05−0.15, Fe: 0.06−0.35, Cu<0.10, Mn: 0.01−1.0, Mg: 0.02−0.60, Cr<0.25, Zn: 0.05−0.70, Ti<0.25, Zr<0.20.
[0013] Cr is maintained preferably below 0.15% and is allowed only for reasons of recycling off-cuts of other alloys. Zn is maintained preferably above 0.1%.
[0014] Patent application WO 02/055750 by the applicant relates to an alloy with improved corrosion resistance composed as follows : 0.20−0.50, Cu<0.05, Mn: 0.5−1.2, Mg<0.05, Zn<0.50, Cr: 0.10−0.30, Ti<0.05, Zr<0.05.
[0015] The problem which the present invention answers is to manufacture a product extruded from alloy 3XXX with improved mechanical resistance, in order to be able to withstand high pressures, especially for operating temperatures ranging between 130 and 170° C., and with identical or higher performance levels in term of manufacture, shaping, assembly and corrosion resistance than those of current products.
SUBJECT OF THE INVENTION
[0016] The subject of the invention is a extruded product, in particular a drawn tube, made of alloy composed as follows (% by weight): Si<0.30, Fe<0.30, Cu<0.05, Mn: 0.5−1.2, Mg 0.5−1.0, Zn<0.20, Cr: 0.10−0.30, Ti<0.05, Zr<0.05, Ni<0.05, others <0.05 each and <0.15 total, the rest aluminum.
[0017] Contents are preferably (% by weight): Si 0.05−0.15, Fe: 0.05−0.25, Cu<0.01, Mn: 0.9−1.1, Mg 0.6−0.9, Zn:<0.05, Cr: 0.15−0.25, Ti<0.04, Zr<0.04, Ni<0.01.
[0018] Another subject of the invention is a manufacturing process for tubes extruded from an alloy according to the invention including casting a billet, possibly homogenizing this billet, spinning a tube, drawing this tube in one or more passes, and continuous annealing at a temperature ranging between 350 and 500° C. with a rise in temperature of less than 10 s.
[0019] Still another subject of the invention is the use of a product extruded according to the to invention in the manufacture of motor vehicles.
DESCRIPTION OF THE INVENTION
[0020] Unless otherwise stated, all indications relating to the chemical composition of alloys are expressed as a percentage by weight. The designation of alloys follows the rules of The Aluminum Association, known to experts in the field, as well as EN standard 573-1. The metallurgical states are defined in European standard EN 515. The chemical composition of standardized aluminum alloys is defined for example in EN standard 573-3. Unless otherwise specified, static mechanical characteristics, i.e. breaking strength R m , yield stress R p0.2 , and elongation at break are determined by a tensile test according to standard EN 10002-1 and EN 754-2. The term “extruded product” includes so-called “drawn” products, i.e. products which are manufactured by spinning followed by drawing.
[0021] Unless otherwise specified, the definitions of European standard EN 12258-1 apply. The alloy of the 3XXX series according to the invention has a relatively high magnesium content and a zinc content low enough to be considered as mere impurities. In contrast to what is learnt from prior art, which recommends adding titanium and zinc to alloys of the series 3XXX to improve their corrosion resistance, the alloy according to the invention has good corrosion behavior with a zinc content and a titanium content low enough to be considered as mere impurities. So the zinc content must be lower than 0.20% by weight, preferably lower than 0.05% by weight and preferably still lower than 0.04% by weight. Similarly, the titanium content must be lower than 0.05% by weight, preferably lower than 0.04% by weight and preferably still lower than 0.03% by weight. In addition, the low zinc and titanium contents are an advantage with regard to recycling the alloy products according to the invention.
[0022] The magnesium content lies between 0.5 and 1.0% by weight and preferably between 0.6 and 0.9% by weight. Adding magnesium with a content of at least 0.5% by weight and preferably at least 0.6% by weight makes it possible to very significantly increase mechanical resistance. The magnesium content must however be limited to a maximum of 1.0% by weight and preferably to 0.9% by weight to ensure satisfactory product solderability and good performance in terms of extrusion potential.
[0023] Adding chromium at a concentration ranging between 0.10 and 0.30% by weight and preferably at a concentration ranging between 0.15 and 0.25% by weight makes it possible to improve the alloy's corrosion resistance.
[0024] Manganese is the main alloy element. It is added at a concentration ranging between 0.5 and 1.2% by weight and preferably at a concentration ranging between 0.9 and 1.1% by weight.
[0025] The iron and silicon content must be lower than 0.30% by weight. Advantageously, the iron content is at the most 0.25% by weight and the silicon content is at the most 0.15% by weight. Too high a content of these elements is a factor in reducing corrosion resistance. It is preferable, mainly for economic reasons of recycling, for silicon and iron contents to be at least 0.05% by weight.
[0026] Adding other elements may have a harmful effect on the alloy, and these must therefore have a content of less than 0.05% by weight and less than 0.15% in total. In particular, the presence of zirconium, nickel or copper may lower corrosion resistance properties, and the content of these elements must be less than 0.05% by weight. Preferably, the nickel and copper content is less than 0.01% by weight and the zirconium content is less than 0.04% by weight.
[0027] The manufacturing process for extruded products, in particular tubes, involves casting billets of the alloy indicated, possibly homogenizing the billets, reheating and spinning them to obtain a straight length of tube or a coil, and, as an option, one or more drawing passes to bring the product to the required dimensions. The tube may, if it is stretched, then advantageously be continuously annealed by running at high speed in a continuous furnace, preferably an induction furnace. The extruded product is very quick to reheat: less than 10 seconds, and preferably less than 2 seconds, and the product runs at a speed ranging between 20 and 200 m/min Furnace temperature is maintained at between 350 and 500° C. After annealing, the product may be drawn again to increase mechanical resistance (state H).
[0028] This continuous annealing gives a microstructure with fine equiaxed grains, of average grain size, measured by the intercept method, of less than 40 μm, and typically about 25 μm. The fine grain microstructure is advantageous especially with regard to the tubes' mechanical properties and corrosion resistance.
[0029] The products according to the invention have high mechanical resistance. So in the H12 state, the breaking strength at room temperature is increased by at least 40% compared to a product according to application WO 02/055750 with a comparable manganese content. Surprisingly, the advantage is even more marked for tests carried out at high temperature. So in the H12 state, the breaking strength at 170° C. is increased by almost 60% compared to a product according to application WO 02/055750 with a comparable manganese content. In particular, products extruded according to the invention have, in H12 state, a breaking strength Rm greater than 150 MPa at room temperature and greater than 140 MPa at 170° C. Moreover, products extruded according to the preferential composition of the invention have, in H12 state, a breaking strength Rm greater than 160 MPa at room temperature and greater than 150 MPa at 170° C. The relative plastic variation R p% , defined by the ratio R p% =(R m −R p0,2 ) R p0,2 , makes it possible to evaluate the potential for plastic deformation without breaking. Products according to the invention have, in H12 state, a plastic variation at room temperature slightly lower than that of products according to application WO 02/055750 but, surprisingly, an improved relative plastic variation for test temperatures higher than, or equal to, 130° C. So in H12 state, the relative plastic variation obtained with products according to the invention is greater than 5% for a test temperature of 140° C. In addition, even after ageing at 130° C., the plastic variation relating to the H12 state is still greater than 5%. Products according to the invention also perform well in terms of corrosion. In particular, products according to the invention do not show deep pitting during a salt spray test of the SWAAT type as per standard ASTM G85A3.
[0030] It is possible that this favorable result is at least partly due to the absence of MgZn 2 precipitates which may form in the event of the simultaneous presence of Mg and Zn and which may have a detrimental effect on corrosion resistance in particular.
[0031] The preferred shape of the product extruded according to the invention is a cylindrical tube comprising only one cavity.
[0032] Products extruded according to the invention can be used in particular as tubes in motor vehicle manufacture. In particular, products extruded according to the invention can be used as lines for fuel, oil, refrigerant or brake fluid for cars, and as tubes designed for heat exchangers for engine cooling and/or air-conditioning systems for motor vehicle passenger compartments, especially if they use CO2 as a refrigerating gas. Tubes, in particular tubes drawn according to the invention, are more particularly suitable for being used in the form of cylindrical tubes, preferably comprising only one cavity for transfer piping for fluid used in air-conditioning systems for motor vehicle passenger compartments using CO2 as a refrigerating gas.
Example
[0033] Billets were cast and homogenized in 3 alloys indexed A to C. Alloys A and B correspond to compositions of alloy AA3103 and alloy compositions according to application WO 02/055750 of prior art respectively. Alloy C complies with the invention. The compositions of the alloys (% by weight) are given in table 1.
[0000]
TABLE 1
Composition of alloys A to C (% by weight).
Ref.
Si
Fe
Cu
Mn
Mg
Cr
Zn
Ti
Zr
Ni
A
0.12
0.56
<0.01
1.11
<0.05
0.02
0.009
0.01
<0.05
<0.01
B
0.10
0.27
<0.01
0.97
<0.05
0.19
0.19
0.01
<0.05
<0.01
C
0.07
0.14
<0.01
0.99
0.65
0.20
0.01
0.01
<0.05
<0.01
[0034] The billets were extruded in coils of tubes then drawn to obtain tubes of a diameter of 12 mm and a thickness of 1.25 mm No significant difference was recorded for the three alloys as far as their potential for spinning and drawing was concerned. These coils were continuously annealed in an induction furnace at a fixed temperature of 470° C., with a throughput speed between 60 and 120 m/min The coils then underwent a new drawing pass to bring them to the H12 state according to standard EN 515. On samples of the 3 tubes, the breaking strength R m (in MPa) and the yield stress R p0.2 (in MPa), were measured at room temperature and, for tubes B and C, at 140° C. and 170° C. in order to simulate the conditions using the tube in an air-conditioning system using CO2 as a refrigerant. The results are given in table 2.
[0000]
TABLE 2
Mechanical characteristics obtained at room temperature and at high temperature
Temperature 20° C.
Temperature 140° C.
Temperature 170° C.
Rp 0.2
Rm
Rp 0.2
Rm
Rp 0.2
Rm
Ref.
(MPa)
(MPa)
R p %
(MPa)
(MPa)
R p %
(MPa)
(MPa)
R p %
A
110
122
11
B
122
132
8
112
112
0
106
106
0
C
177
187
6
160
172
8
154
169
10
[0035] It should be noted that alloy C according to the invention gives greatly improved mechanical resistance as compared to alloy B for a test carried out at room temperature, and even more greatly improved for a test carried out at 170° C. The breaking strength is improved by approximately 40% at room temperature and approximately 60% at 170° C. The plastic variation for the tests carried out at a temperature of at least 140° C. is also greatly improved, moving from 0% for alloy B to more than 5% for alloy C for temperatures of 140° C. and 170° C. The breaking strength and the yield stress properties of alloy C were also measured at 130° C. after ageing for 72 h at 130° C. and 1000 h at 130° C., and were measured at 165° C. after ageing for 72 h at 165° C. and 1000 h at 165° C. For comparison purposes, alloy B was characterized only under the severest conditions, i.e. measured at 165° C. after ageing for 1000 h at 165° C. The results are given in table 3.
[0000]
TABLE 3
Mechanical characteristics obtained
after ageing at high temperature.
Treatment
72 h at
1000 h at
72 h at
1000 h at
130° C.
130° C.
165° C.
165° C.
Test temperature
Alloy
130° C.
130° C.
165° C.
165° C.
B
R p0.2 (MPa)
—
—
—
99
B
R m (MPa)
—
—
—
101
B
R p %
—
2
C
R p0.2 (MPa)
167
167
148
140
C
R m (MPa)
186
180
150
143
C
R p %
11
8
1
2
[0036] It can be observed that alloy C according to the invention conserves definitely improved breaking strength and yield stress mechanical properties after ageing, since these increase by 40% in relation to alloy B.
[0037] The average grain size was measured by the intercept method on samples of the 3 tubes. The results are given in table 4. The tubes obtained with the 3 alloys have fine equiaxed grains of about 20 μm.
[0000]
TABLE 4
Average grain size measured by the intercept method.
Direction L
Direction T
Average
Alloy
(μm)
(μm)
(μm)
A
22
18
20
B
20
16
18
C
21
18
20
[0038] Corrosion resistance was measured using the SWAAT test (Sea Water Acetic Acid Test) as per standard ASTM G85 A3. Measurements were made for durations of 500 cycles at a temperature of 49° C., on three tubes of length 200 mm of each alloy A, B and C. At the end of the test, the tubes were removed from the enclosure and pickled in a 68% nitric acid solution in order to dissolve the corrosion products. The depth of pitting was then measured optically on the surface of each tube by defocusing, and the average depths of the 5 deepest pits were calculated. The average PAv of the values obtained for the 3 tubes was then calculated. Corrosion resistance improves as PAv decreases. The results of 5 successive SWAAT test campaigns are given in table 5. The number of * signs indicates the number of tubes bored in the batch of three tube tested.
[0000]
TABLE 5
Results obtained with the SWAAT corrosion test.
Test
Alloy A
Alloy B
Alloy C
campaign
PAv (μm)
PAv (μm)
PAv (μm)
1
1166 **
216
Not tested
2
1250 ***
213
Not tested
3
1139
234
Not tested
4
Not tested
431
305
5
1250 ***
321
488
[0039] It can be seen that alloy C according to the invention has a corrosion behavior equivalent to that of alloy B of prior art and definitely improved in relation to that of alloy A. Alloy C has no deep pitting, given that within the context of this invention the term “deep pitting” means a PAv value greater than 0.5 mm
[0040] The composition according to the invention and in particular adding Mg and the absence of Zn makes it possible to spectacularly improve mechanical resistance, in particular for temperatures ranging between 130° C. and 170° C., without detriment to corrosion resistance, as compared to alloy B. | An extruded product, in particular a tube, made of alloy composed as follows (% by weight): Si<0.30, Fe:<0.30, Cu<0.05, Mn: 0.5−1.2, Mg 0.5−1.0, Zn<0.20, Cr: 0.10−0.30, Ti<0.05, Zr<0.05, Ni<0.05, others<0.05 each and<0.15 total, the remainder aluminum. The invention is further directed to a manufacturing process for tubes extruded from this composition including the steps of casting a billet, optionally homogenizing this billet, extruding a tube, drawing this tube in one or more passes, and continuously annealing at a temperature ranging between 350 and 500° C. with a rise in temperature of less than 10 seconds. The tubes according to the invention are advantageously used for air-conditioning systems for the passenger compartment of motor vehicles using CO 2 as a refrigerating gas. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit, under 35 U.S.C. § 365 of International Application PCT/US03/11564, filed Apr. 16, 2003, which was published in accordance with PCT Article 21(2) on Oct. 30, 2003 in English and which claims the benefit of U.S. Provisional Patent Application No. 60/374,281, filed Apr. 19, 2002.
This invention relates to video displays, and more particularly to power supply arrangements for displays which may operate at different frequencies.
BACKGROUND OF THE INVENTION
Multifrequency video displays or monitors are used for both High Definition Television (HDTV) and National Television Standards Committee (NTSC) television viewing and for computer applications. At the current state of the art, charge-coupled device (CCD) displays tend to be costly, or unavailable, especially in large sizes, and in general are not as bright as kinescope or picture-tube types of displays. Plasma displays are not common. Thus, the kinescope display is in common use.
Kinescope displays are ordinarily scanned by means of inductive or electromagnetic yokes near the neck of the kinescope, to which both vertical and horizontal scan currents are applied, to create magnetic fields which deviate one or more electron beams traversing the tube to the phosphorescent display screen. National Television Standards Committee (NTSC) standards for conventional television specify a horizontal scanning frequency of about 15,734 Hz, and a vertical scan frequency of 60 Hz. A large body of art has grown up around vertical and horizontal deflection circuits. Because of the relatively high horizontal scan frequency and significant power involved in performing horizontal scan, the horizontal deflection scanning circuits commonly operate in a resonant retrace mode, in which currents and the associated power are recirculated back to the power source for re-use during the next following scan cycle.
The amplitude of current circulating in a resonant horizontal deflection circuit is mainly determined by the value of the B+ voltage. It is also determined, at least in part, by the desired scan frequency. For a given horizontal deflection system with a fixed value of kinescope ultor (High) voltage, a fixed amount of overscan, and a horizontal deflection yoke having a fixed inductance, the product of the scan time multiplied by the deflection circuit B+ tends to be a constant. Thus, the value of energizing voltage or B+ applied to the horizontal deflection circuit multiplied by the scan time is desirably constant. In the past, many video display systems were designed to apply a constant B+ to the horizontal deflection system.
With the advent of HDTV, many different video formats are available to the consumer. Some of these formats have vertical and horizontal deflection frequencies which differ from those of conventional NTSC broadcast television signals. The higher definition associated with HDTV implies a higher horizontal deflection frequency than for standard-definition television. As the horizontal frequency increases, the scan time must decrease, unless the frequency difference is very small and can be taken up in the retrace time. For most television systems in which the horizontal scanning frequency is varied, the retrace time is held constant, and the scan time is varied. Thus, as the horizontal scanning frequency is increased, the scan time is decreased, and the scan B+ is also increased so that the product of the scan time multiplied by the B+ is a constant.
Many present-day television display devices, including television receivers, derive their scan B+ voltage from a switch mode power supply (SMPS) including inductive elements and a transformer having a secondary winding. The scan B+ is generated from the scan secondary winding by rectification of SMPS pulsatory signals and subsequent filtration. In many such display devices, in order to avoid the need for plural power supplies, the SMPS must also supply auxiliary or ancillary voltages, for operation of systems or circuits other than the horizontal deflection system. In a television receiver, for example, the ancillary systems may include RF and IF processors, video and sound processors, convergence, and others. These ancillary systems ordinarily require that their energizing voltages remain constant, regardless of the horizontal deflection frequency which happens to be in use. The ancillary energizing voltages may be derived from secondary windings of the SMPS transformer other than the one from which the horizontal scan or deflection B+ is derived. However, simply deriving the ancillary energizing voltages from a separate secondary winding will not guarantee that the ancillary energizing voltage does not change. Since the number of turns per winding in the SMPS transformer is fixed, changing the horizontal scan B+, without more, also changes the ancillary energizing voltage.
Improved video display arrangements are desired.
SUMMARY OF THE INVENTION
A video display apparatus according to an aspect of the invention comprises a deflection circuit output stage for selectively generating a deflection current in a deflection winding at a first deflection frequency and at a second deflection frequency, and a power supply for producing, via a common power transistor of an output stage, a first supply voltage at a first terminal and a second supply voltage at a second terminal. A first switch is responsive to a control signal indicative of the selected deflection frequency, for selectively coupling the first supply voltage to the deflection circuit output stage when the first deflection frequency is selected, and the second supply voltage, when the second deflection frequency is selected. A power supply regulator is responsive to at least one of the first and second supply voltages for regulating the at least one of the first and second supply voltages via a negative feedback path.
In a particular version of the video display according to this aspect of the invention, a second switch is responsive to a control signal that is indicative of the selected frequency and coupled in the negative feedback path. The second switch has a first state when the deflection current is at the first deflection frequency, and has a second state when the deflection current is at the second deflection frequency, for providing coarse adjustment. In another avatar of this version of the video display, a source of a fine adjustment signal is coupled to the negative feedback path for providing fine adjustment. In a hypostasis of this avatar, a portion of the negative feedback path contains information derived from at least one of the first and second supply voltages, information derived from the state of the second switch and information derived from the fine adjustment signal.
In another particular version of the video display according to this aspect of the invention, each of the first and second supply voltages is regulated via the negative feedback path.
In yet another particular version of the video display according to this aspect of the invention, an output transformer is coupled to the power transistor for producing the first supply voltage from a voltage developed in a first transformer winding and the second supply voltage from a voltage developed in a second transformer winding of the transformer, and the transformer has a third transformer winding for producing a third supply voltage that is coupled to a load circuit, wherein a volts-per-turn ratio in the third transformer winding remains the same at each of the first and second deflection frequencies.
In yet a further particular version, an output transformer is coupled to the power transistor for producing the first and second supply voltages, and the transformer has a transformer winding for producing a third supply voltage that is coupled to a load circuit, wherein a volts-per-turn ratio in the transformer winding remains the same at each of the first and second deflection frequencies.
In another particular version, the power supply regulator is responsive to a feedback signal produced at an output terminal of the first switch for regulating each of the first and second supply voltages.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified schematic diagram of a portion of a television receiver according to an aspect of the invention; and
FIG. 2 is a more detailed, but still simplified, diagram of a portion of the arrangement of FIG. 1 .
DESCRIPTION OF THE INVENTION
In FIG. 1 , a system designated generally as 10 includes a kinescope 12 associated with a vertical deflection coil 12 V and a horizontal deflection coil 12 H. A block 20 represents ancillary equipment, which may include, for example, any or all of kinescope cathode drivers, radio-frequency receivers and intermediate-frequency amplifiers, demodulators, audio circuits, video processors, and the like, all well known for use in television and video display apparatus. A horizontal deflection or scan circuit, illustrated as a block 100 , is connected to horizontal deflection coil 12 H for applying horizontal scan signals thereto, for causing the desired horizontal deflection, at a selected horizontal scan frequency H 1 or H 2 controlled by a source illustrated as a block 102 . Horizontal deflection circuit 100 receives an energizing voltage designated as B+ at an energizing voltage input port 100 i.
In FIG. 1 , a switch-mode power supply (SMPS) designated generally as 30 includes a power transformer T 1 including a primary winding T 1 P connected to power transformer T 1 terminals 2 and 4 , a magnetic core designated TIC, a first secondary winding T 1 S 1 including a first portion T 1 S 1 a connected to transformer terminals 16 and 18 , and a second portion T 1 S 1 b connected to transformer terminals 16 and 19 , and a regeneration or oscillation inducing feedback winding T 1 f connected to transformer terminals 1 and 8 . One end of secondary winding portion T 1 S 1 a is connected to ground by way of terminal 18 . Since both secondary winding portions T 1 S 1 a and T 1 S 1 b are connected to transformer terminal 16 and the remote end of portion T 1 S 1 a is connected to ground, terminal 16 may be considered to be a tap on secondary winding T 1 S 1 . Viewed another way, the end of secondary winding portion T 1 S 1 b remote from terminal 16 is connected to a terminal 19 , so that the two serially-connected portions of secondary winding T 1 S 1 form a tapped secondary winding with a tap terminal 16 .
Secondary winding T 1 S 2 of FIG. 1 has one end coupled to ground by way of a terminal 14 , and the other end connected to a terminal 13 . Secondary winding T 1 S 2 represents any one of a plurality of such windings which may be associated with transformer T 1 , each producing a different or independent output voltage or power for energizing various portions of the apparatus 10 .
Also in FIG. 1 , a block 32 represents the electronics and power switching portion of switch mode power supply 30 . Primary winding T 1 P terminals 2 and 4 of transformer T 1 are connected to SMPS electronics and Power switching block terminals 32 2 and 32 4 , respectively, and feedback secondary winding T 1 f terminals 1 and 8 are connected to SMPS electronics and power switching block terminals 32 1 and 32 8 , respectively. SMPS electronics and power switching portion 32 receives raw B+ as its source of energizing power at a terminal designated RAW B+ relative to an isolated ground, illustrated by a downward-pointing open triangle symbol 32 ig . SMPS electronics and power switching portion 32 switches the power B+ applied to primary winding T 1 P of transformer T 1 so as to periodically store energy in the inductance associated with the winding, and to allow the energy so stored to produce pulsating or pulsatory (alternating) voltages on secondary windings T 1 S 1 , T 1 S 2 , and T 1 f . The pulsatory voltage generated on secondary winding T 1 f is coupled back to the electronics and power switching portion 32 of switch mode power supply 30 by way of a terminals 32 1 and 32 8 to aid in sustaining oscillation. The pulsatory voltages appearing on secondary windings T 1 S 1 and T 1 S 2 are rectified, as known in the art, to produce pulsatory currents which are smoothed by filtering to produce the desired direct energizing voltages. More particularly, the pulsatory voltage produced at transformer terminal 16 by secondary winding portion T 1 S 1 a is rectified by a unidirectional current conducting device illustrated as a diode or rectifier CR 107 to produce a voltage at terminal 02 , and applied to a filter designated as F 101 to be smoothed to produce a first “Scan B+” voltage for application to horizontal deflection circuit 100 . Similarly, the pulsatory voltage produced at transformer terminal 13 by secondary winding T 1 S 2 is rectified by a unidirectional current conducting device illustrated as a diode or rectifier CR 108 , and applied to a filter designated as F 102 to be smoothed to produce a direct voltage B 2 for application over a path Pa to the ancillary equipment illustrated as block 20 .
In FIG. 1 , the pulsatory voltage produced at terminal 19 of transformer T 1 is greater than the pulsatory voltage produced at tap terminal 16 , because of the additional voltage added by winding T 1 S 1 b to that voltage appearing at terminal 16 . The voltage at terminal 19 is applied to a unidirectional current conducting device illustrated as a diode or rectifier CR 106 . The pulsatory voltage available at the cathode of device CR 106 is applied to a terminal K 1 of a relay K 101 . Relay K 101 also has a winding KW which, when energized, causes movable contact element K 2 to connect to contact K 1 , but in the illustrated unenergized state of relay K 101 , such contact is not made, and no current flows in unidirectional current conducting device CR 106 .
In the arrangement of FIG. 1 , the scan B+ voltage at the output of smoothing filter F 101 is applied by way of a path 34 to a power supply controller designated generally as 38 , which includes a voltage divider 22 and an error amplifier U 103 . Voltage divider 22 includes three resistors, namely resistors R 117 , R 118 , and R 119 , having tap points 22 1 and 22 2 between them. The scan B+ voltage is divided in a (reduced by a) fixed ratio by voltage divider 22 and applied from tap 22 1 to a reference input terminal or port U 103 i of an error amplifier illustrated as U 103 , which in this particular embodiment is a type TL431 integrated circuit, manufactured by Texas Instruments, NEC, Samsung, and others. Error amplifier U 103 has its terminal U 103 g connected to ground by way of a resistor R 139 . Error amplifier U 103 compares the divided feedback voltage with an internal reference voltage and produces a feedback error signal which is coupled to an error signal input terminal 32 5 of SMPS electronics and switch circuit 32 , for control of the switching power supply 30 in known degenerative fashion.
As so far described, the switch mode power supply 30 senses the Scan B+ voltage applied to horizontal deflection circuit 100 , and uses feedback to control that sensed voltage. So long as the feedback control of the Scan B+ voltage continues, the horizontal deflection circuit 100 and the ancillary equipments 20 are correctly energized. According to an aspect of the invention, the H drive source 102 is capable of driving the horizontal deflection circuit 100 at different or disparate horizontal frequencies, designated H 1 and H 2 . In one embodiment of the invention, H 1 is about twice the NTSC horizontal frequency of 15,734 Hz., corresponding to about 31,468 Hz., and H 2 is about 2.14 times the NTSC horizontal frequency, corresponding to about 33,750 Hz. The Scan B+ voltage applied to power input terminal 100 i of horizontal deflection block 100 is required to change when the operating deflection frequency is changed, to maintain the constant product of Scan B+ multiplied by the reduced scan time engendered by the higher operating frequency. In particular, the Scan B+ voltage applied to input port 100 i of horizontal deflection circuit 100 must theoretically increase by a factor of 2.14/2, or 1.07, in order to maintain constant product for an operating frequency change of 2.14/2, but which may deviate due to different amounts of overscan.
In FIG. 1 , regulator B+ switching signal REGB+_SW is applied by way of a port 24 and a signal path 26 to H source 102 for selecting either the 2H or 2.24H horizontal operating frequency. Switching signal REGB+_SW has a logic low level when the horizontal frequency is to be 2H and a high level when the horizontal frequency is to be 2.14H. In order to raise the Scan B+ voltage, it would be a simple matter to adjust the feedback voltage divider 22 to a different division ratio, to thereby increase the power stored by the switch mode power supply in the primary winding T 1 P of transformer T 1 during each operating cycle, thereby increasing the pulsatory voltage produced by secondary winding T 1 S 1 a and the rectified pulsatory voltage produced by diode CR 107 . This would have the effect, however, of increasing the volts-per-turn of all the secondary windings of transformer T 1 , with the result that the voltage produced by representative secondary winding T 1 S 2 , diode CR 108 , and filter F 102 for application to the ancillary equipment illustrated as block 20 , which in turn would undesirably result in a proportional increase in the ancillary energizing voltage.
Instead, according to an aspect of the invention, the Scan B+ voltage applied to the horizontal deflection circuit 100 is changed by switching another secondary winding, by means of relay K 101 , into circuit with smoothing filter F 101 . The feedback ratio is also changed to provide the same feedback voltage to the error amplifier so the volts-per-turn does not change as a function of the change in Scan B+. The change of the Scan B+ is accomplished by additionally applying switching signal REGB+_SW to the base of a grounded-emitter transistor Q 105 , to turn ON transistor Q 105 when the REGB+_SW voltage has a high level for selecting the higher 2.14H scan frequency. When the higher scan frequency is selected, the scan time decreases, and the Scan B+ voltage must increase. The increase in scan voltage is accomplished by relay K 101 , in which a magnetic winding KW is energized by transistor Q 105 in its ON state. When relay K 101 magnetic winding KW is energized, movable element K 2 is brought into conductive contact with stationary element K 1 , so that the rectified pulsatory voltage at the cathode of diode CR 106 is applied to smoothing filter F 101 . The pulsatory voltage from CR 106 , being greater than the pulsatory voltage from diode CR 107 , keeps diode CR 107 turned OFF (causes CR 107 to cease conduction). In effect, relay K 101 disconnects CR 107 and its associated winding T 1 S 1 a from filter F 101 , and connects CR 106 and its associated pair of windings T 1 S 1 a , T 1 S 1 b to the filter. Since the rectified pulsatory voltage produced by CR 106 is greater than that produced by CR 107 , the smoothed B+ is also greater when relay K 101 is energized for 2.14H operation.
SMPS electronics and power switch 32 of FIG. 1 responds to degenerative error signals applied to its error signal input port 32 5 from error amplifier U 103 . SMPS electronics and power switch 32 adjusts its switch timing and/or frequency in such a manner as to tend to control the amount of energy stored in transformer primary winding T 1 during each switch cycle in response to the error signal. If the error signal changes as a result of the change in the magnitude of the Scan B+ engendered by the switching of relay K 101 , the ancillary supply voltages produced by representative secondary winding T 1 S 2 , diode CR 108 , and filter F 102 will change, and more particularly the voltage produced by secondary winding T 1 S 2 , diode CR 108 , and filter F 102 will decrease when relay K 101 is energized if the feedback ratio is not adjusted.
According to an aspect of the invention, the feedback voltage division is changed, preferably in proportion to the change in the nominal Scan B+ which results from the switching of Relay K 101 . More particularly, in FIG. 1 , the REGB+_SW signal applied by way of terminal 24 and path 26 to H source 102 and to transistor Q 105 is also applied to the base of a further grounded-emitter transistor Q 104 . Transistor Q 104 thus becomes conductive or ON when signal REGB+_SW is logic high. When Q 104 is conductive, a resistor R 120 is introduced into voltage divider 22 , to increase the division ratio. Put another way, the divided feedback signal at tap 22 1 is reduced when the Scan B+ voltage is increased, so that the feedback voltage applied to error amplifier U 103 remains the same, at least in principle. Thus, regardless of whether the Scan B+ voltage is derived from CR 107 and is relatively low, or is derived from CR 106 and is relatively high, the feedback sample at the input port of error amplifier U 103 remains the same. Since the feedback signal remains the same as a result of the switching of the coupling ratio of the feedback path, SMPS electronics and switch block 32 continues to transfer the same amount of energy per cycle to the secondary windings, including secondary winding T 1 S 2 . When secondary winding T 1 S 2 receives the same energy per cycle, the ancillary power supply including CR 108 and filter F 102 produces the same output voltage for operating the ancillary equipment 20 .
In FIG. 1 , an additional circuit 39 allows remote control of the magnitude of the Scan B+ voltage. The additional circuit 39 includes a memory (MEM) illustrated as a block 40 , together with a digital-to-analog converter (DAC), for producing a signal B+ALIGN. Signal B+ALIGN is applied to the base of a transistor Q 108 by way of a temperature compensating diode CR 112 and a voltage divider including resistors R 127 , R 128 , and R 129 . Transistor Q 108 has its emitter coupled by a resistor R 130 , so it produces a collector current which is linearly responsive to the magnitude of B+ALIGN, and produces an additional offset of the feedback signal at tap point 22 1 of voltage divider 22 , which can be used to perform fine adjustment of the Scan B+ voltage. The memory 40 is active during all the horizontal frequency modes, but accesses different memory locations under the control of REGB+_SW. The memory locations are preprogrammed with values which compensate for tolerances. An advantage of this arrangement is that the coarse adjustment of the feedback ratio is provided by resistor R 120 , and the combination of memory 40 and DAC 42 can be used over its full dynamic range for trimming the Scan B+voltage.
The error signal produced by U 103 by comparing the feedback Scan B+ signal from tap 22 1 of voltage divider 22 of FIG. 1 is applied by way of error signal input port 32 5 of FIG. 2 to input terminal U 101 2 of a photocoupler or optoisolator U 101 . Optoisolator U 101 provides isolation between those portions of the display unit 10 of FIG. 1 which are at line potential and isolated from ground and the user-accessible or grounded portions of the SMPS electronics and switch block 32 . A resistor R 137 is coupled from terminal U 101 1 of U 101 to terminal U 101 2 , and terminal U 101 1 is connected by a resistor R 114 to a +15 v source.
In FIG. 2 , the primary winding T 1 P is illustrated in phantom across terminals 32 2 and 32 4 to aid understanding. Power FET switch Q 101 alternately switches terminal 32 4 of primary winding T 1 P to isolated ground by way of a current sensing resistor R 109 . Since terminal 32 2 of primary winding T 1 P is connected to Raw B+, the switching of Q 101 switches primary winding T 1 P across Raw B+. During those intervals in which Q 101 is conductive, current through T 1 P and through R 109 increases, with a concomitant increase in the energy stored in the inductance of the primary winding. Also during those intervals in which Q 101 is conductive and current is increasing in primary winding T 1 P, a positive-going (+) feedback voltage is generated at terminal 32 1 of feedback secondary winding T 1 f relative to isolated ground. This positive-going voltage is fed by way of a resistor R 110 , a path 210 , capacitor C 104 , and resistors R 106 and R 107 to the gate of power switch Q 101 , to tend to hold Q 101 in a conductive state. A capacitor C 140 , connected to the gate of Q 101 , co-acts with resistors R 106 and R 107 to limit the rise time of the applied gate voltage, to thereby tend to reduce radio-frequency interference.
The voltage at terminal 32 1 of FIG. 2 relative to isolated ground alternates during the cyclical operation of the SMPS of FIG. 2 . This alternating voltage is used to drive to separate power supplies, one of which is associated with CR 104 , and the other of which is associated with CR 102 . The first power supply has a charge path which includes R 110 , CR 104 , C 120 , and terminal 32 8 of secondary winding T 1 f , and it charges the non-grounded end of capacitor C 120 to a negative voltage, which in a particular embodiment is about −9 or −10 volts.
The second power supply of FIG. 2 includes CR 102 and capacitor C 108 , and it produces a positive voltage which tends to be proportional to the magnitude of the raw B+, because increasing B+ increases the voltage across the primary winding T 1 P, which in turn increases the voltage across secondary winding T 1 f . The negative voltage produced by the first power supply across capacitor C 120 tends to be generated during the time that the regulated voltages are generated, and therefore tends to be constant.
The emitter of Q 103 of FIG. 2 cannot rise to a voltage above isolated ground greater than +0.7 volts, because of the presence of diode CR 105 . Whenever the optically-controlled transistor 214 connected between terminals U 101 4 and U 101 3 of U 101 conducts, the emitter of Q 103 is taken to a negative voltage relative to isolated ground. CR 103 provides transient protection. Capacitor C 111 is a filter for the control voltage, and is associated with the loop time constant.
Transistors Q 102 and Q 103 are “SCR-connected” in a regenerative fashion in FIG. 2 , so that if Q 103 is turned ON, Q 102 is also turned ON, and tends to remain ON. The SCR-connected pair is coupled between the gate of power switch Q 101 and, when transistor 214 of optoisolator U 101 is conductive, the negative voltage at the nongrounded terminal of capacitor C 111 . Thus, when the SCR-connected pair Q 102 , Q 103 is conductive, power switch Q 101 becomes less conductive, which in turn tends to produce a more negative voltage at its gate, so Q 101 turns OFF in a regenerative fashion. The SCR-connected pair Q 102 , 103 is controlled by the “sawtooth” voltage appearing across current sensing resistor R 109 , in the source circuit of power switch Q 101 . More particularly, as the current increases in primary winding T 1 P as a result of conduction of Q 101 , the increasingly positive voltage on R 109 is coupled by way of a filter, including a capacitor C 107 and a resistor R 108 , to the base of Q 103 . When the base voltage is high enough, Q 103 will turn ON, thereby turning ON Q 102 , and the conduction of the pair discharges the gate of Q 101 , and turns Q 101 OFF. With Q 101 OFF, energy stored in the inductance associated with transformer T 1 is coupled as voltage to the various secondary windings T 1 f , T 1 S 1 , and T 1 S 2 , and is available for use.
The voltage on feedback secondary winding T 1 f reverses when Q 101 turns OFF, becoming negative on terminal 32 1 . The negative voltage is coupled to the gate of Q 101 by way of resistor R 110 , path 210 , capacitor C 104 , and resistors R 106 and R 107 , to tend to hold Q 101 in the OFF state, and also turns OFF SCR-connected pair Q 102 , 103 . Looking at it another way, the current in the SCR-connected pair must be taken low enough to reduce the sum of the alphas of the transistors below unity. Resistors R 103 and 104 are start-up resistors. Once started, the circuit is regenerative. When the energy stored in the primary winding is exhausted into the secondary power supplies, the voltage on the primary winding decreases, which tends to make 32 1 more positive. This positive-going voltage is communicated to the gate of Q 101 to again turn ON Q 101 .
The magnitude of the positive voltage on C 108 tends to become more positive as the Raw B+ increases, and this more positive value is communicated by way of a resistor R 111 to the base of Q 103 , thereby tending to turn ON the SCR-connected pair earlier in the cycle, to compensate for the effects of a larger Raw B+. Resistor R 112 decreases response time to a high load.
Feedback control of the Scan B+ of FIG. 1 is accomplished by coupling the error signal from error amplifier U 103 to error input port 32 5 of FIG. 2 . An increasing value of Scan B+ causes an increasing error current from error amplifier u 103 . An increasing error current from U 103 through the photodiode 212 of optoisolator U 101 causes more photons to be emitted, which is equivalent to increasing base current in transistor 214 . The increasing effective base current, in turn, causes transistor 214 to conduct more heavily, thereby tending to render the emitter of Q 103 of the SCR-connected pair Q 102 , 103 more negative. With the emitter of Q 103 more negative, it and the SCR-connected pair, will become conductive at a lower value of sawtooth voltage from current sensing resistor R 109 . The turn-ON of the SCR-connected pair is related to the turn-OFF of Q 101 . Thus, a tendency for an increase in the Scan B+ results in a tendency to turn power switch Q 101 OFF at a lower value of current, which results in storage of less energy in the inductance associated with transformer T 1 for that operating cycle. The storage of less energy for the cycle tends to reduce the Scan B+, and the degenerative feedback control is accomplished. In FIG. 2 , R 113 is a slow-start resistor which slows down the initial turn-on, and provides some fold-back. Resistor R 115 provides a current limit for the transistor 214 in U 101 .
Other embodiments of the invention will be apparent to those skilled in the art. For example, While serial windings T 1 S 1 a and T 1 S 1 b have been described for producing the scan B+, they could alternatively be in separate, mutually parallel windings, with the voltage of winding T 1 S 1 b being greater than that of winding T 1 S 1 a.
In the embodiment of FIG. 1 , the elements have the following characteristics.
Scan B+
124/134 volts
F101
220□F, 22□H, 100□F
F102
680□F, 27□H, 10□F
R117
120K ohms
R118
15K ohms
R119
3K ohms
R120
200K ohms
R127
6K2 ohms
R128
1M ohms
R129
10K ohms
R130
62K ohms
R139
10 ohms
T1P
36 turns
T1S1a
23 turns
T1S1b
2 turns
T1S2
3 turns
T1f
2 turns
Q104
Motorola BC847B
Q105
Motorola MPSa06
Q108
Motorola BC847B
In the embodiment of FIG. 2 , the elements have the following characteristics.
C103
1.1 nF
C104
100 nF
C105
470 pF
C107
1 nF
C108
47 nF
C109
330 pF
C110
330 pF
C111
100 nF
C112
220 pF
C120
2.2 □F
C138
180 pF
C140
470 pF
Q101
Infinion SPP1N60C2
Q102
Motorlay MPS 8599
Q103
Motorola MPSA06
CR103
16 volts
R101
51K ohms
R103
100K ohms
R104
120K ohms
R105
330 ohms
R106
430 ohms
R107
75 ohms
R108
510 ohms
R109
0.22 ohms
R110
68 ohms
R111
22K ohms
R112
10K ohms
R114
1.1K ohms
R115
680 ohms
R137
1K ohms | A video display includes a scanner operable at a first frequency and a higher second frequency. A switch mode power supply drives a transformer with three secondaries. First and second rectifiers & filters are associated with the first and second secondaries. A rectifier is coupled to the third secondary and by way of a switch to the first filter. Feedback from the first filter controls the SMPS. In a first operating mode, the scanner is operated at the first frequency, the switch is open, the scanner supply is a first voltage from the first filter, and ancillary equipment is supplied with a third voltage by the second filter. In a second operating mode, the scanner is operated at the second frequency, the switch is closed, the scanner supply is a second voltage, higher than the first, from the first filter, and ancillary equipment is supplied with the same third voltage. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a flat panel display of a type having a pattern of constituent elements arranged in correspondence with an arrangement of cells in a display region.
2. Description of the Prior Art
In the course of mass production of flat panel displays (FPDs) such as, for example, plasma display panels, liquid crystal display panels and organic electroluminescence display panels, attempts have hitherto been made to minimize indirect materials of a kind utilized solely for the convenience of manufacture thereof. The indirect materials are, when intended products are completed, in most cases disposed of as wastes and, therefore, the need has been well recognized to minimize the indirect materials not only to avoid concomitant increase of the manufacturing cost, but also to avoid environmental contamination.
The Japanese Laid-open Patent Publication No. 11-273557, published in 1999, discloses the use of an ink jetting technique to form electrodes of the plasma display panel. The ink jetting technique in which an electroconductive inking material is jetted towards a substrate so as to depict a pattern of electrodes is considered economically efficient as compared with the photolithographic technique in which portions of a uniform layer of electrode material are removed to leave a pattern of electrodes. Also, as compared with the screen printing technique, the ink jetting technique is considered effective not only in facilitating accurate formation of the pattern of electrodes with high uniformity over the entire surface of a large size screen, but also substantially eliminating the need of replacement of screens, which would otherwise be performed frequently, resulting in reduction in cost and reduction in length of time required to complete the products.
However, the ink jetting technique involves the following problems when the pattern of electrodes for flat panel display is to be formed:
(1) Unless the support surface on which the electrode pattern is desired to be formed has an excellent wettability, the inking material being jetted tends to scatter and/or fluidize. (2) Microscopic irregularities peculiar to those occurring when liquid droplets are deposited tend to be observed in edges of the electrode pattern.
As a technique effective to substantially eliminate the above discussed problems and to form a layer of inking material representing the electrode patterns having a smooth contour, the above mentioned patent publication suggests a method of masking, with a photoresist, an area other than the area onto which the inking material is deposited and a method of shaping the pattern edge by the use of exposure and development subsequent to formation of the electrode pattern with a photosensitive inking material.
The Japanese Patent No. 3395841 discloses a method of making a color filter for a liquid crystal display panel, which method includes forming on a substrate a photocatalyst containing layer, of which wettability varies when irradiated with energies, and irradiating the substrate with energies in a predetermined pattern to enhance the wettability of a portion of the photocatalyst containing layer and depositing a colored ink on the wettability enhanced portion of the photocatalyst containing layer. In other words, this Japanese patent discloses enhancement of the wettability of only a portion of the predetermined pattern formed on the support surface.
In the manufacture of the FPDs hitherto practiced, the use of the ink jetting technique is effective to reduce the amount of direct materials used, but a number of indirect materials are needed and/or special materials must be used to render the resultant electrode pattern to be neatly finished. Masking with the photoresist requires a substantial amount of resist materials so that the latter can be deposited on the entire area of the supporting surface, i.e., a substrate and, also, requires complicated process steps. The use of the photosensitive ink would undesirably recede the merit of reduction of the amount of the direct materials used. Yet, even where a film material effective to vary the wettability of the photocatalyst containing layer, discussed above, when irradiated with energies is employed, the film material in a quantity enough to cover the entire surface of the substrate uniformly is needed.
SUMMARY OF THE INVENTION
Accordingly, the present invention has for its primary object to enable formation of a pattern of constituent elements, arranged in correspondence with an arrangement of cells in a display region, as desired or required with a minimized quantity of the film material.
In order to accomplish this and other objects of the present invention, there is provided a method of manufacturing a flat display panel, which includes printing on a substrate a surface treating material of a kind capable of partially enhancing the wettability of the substrate, in a predetermined pattern sufficient to encompass the eventually formed pattern of constituent elements of the flat display panel. The surface treating material so printed forms an undercoat on the substrate which is subsequently patterned by irradiation of light. Thereafter, a film material eventually forming the constituent elements in a pattern on the substrate is selectively deposited on the substrate by the utilization of the undercoat to thereby complete the predetermined pattern of the constituent elements.
According to the present invention, since the area of the substrate on which the undercoat is formed is a localized surface area of the substrate, not the entire surface area of the substrate, the amount of the surface treating material used can advantageously be reduced to a value smaller than that that would be required to deposit the undercoat on the entire surface area of the substrate. The smaller the area of the substrate occupied by the constituent elements, the more savable the amount of the surface treating material.
Patterning of the undercoat on the substrate may be accomplished in various ways. For example, a technique of partially removing the undercoat by irradiation of a laser beam or a technique of partially modifying the undercoat by irradiation of ultraviolet rays of light may be employed. In particular, irradiation of the laser beam may be carried out according to either a delineating scheme or a pattern exposure scheme and irradiation of the ultraviolet rays of light may be carried out according to a pattern exposure scheme. For the patterning that is performed in the practice of the present invention, a highly precise patterning technique must be employed, rather than a mere pattern printing technique. The patterning performed in the practice of the present invention is effective to provide a highly precise pattern of the constituent elements on the substrate more accurately than that accomplished by the use of the pattern printing such as, for example, the screen printing.
Selective deposition of the film material on the patterned undercoat may be suitably carried out by the use of an ink jetting technique. Where the substrate has a high ink repellent property and the film material is of a kind that can be highly selectively deposited on the undercoat, a full surface printing process which can be practiced by the use of a coating apparatus such as, for example, a die coater can be suitably employed. This is because, since even though the inking material is applied to the entire surface area of the substrate, the inking material does not deposit on the surface area of the substrate other than that occupied by the undercoat, that is, the inking material can be deposited only on the undercoat, the amount of the inking material used is comparable to that used when the undercoat is selectively coated.
As discussed above, the present invention is advantageous in that the amount of the film material needed to form the constituent elements of the pattern arranged in conformity with an arrangement of cells on the screen can advantageously be minimized.
Specifically, since the amount of the film material needed to form the constituent elements of the predetermined pattern can advantageously be minimized, the present invention can bring about a contribution to reduction in cost of the flat display panel. Also, the present invention can find an application not only in formation of the electrodes employed in the plasma display panel, but also in formation of a light shielding pattern and/or color filters on the front substrate used in the plasma display panel, formation of fluorescent coatings used in the plasma display panel and formation of color filters used in a liquid crystal display panel.
BRIEF DESCRIPTION OF THE DRAWINGS
In any event, the present invention will become more clearly understood from the following description of preferred embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and:
FIG. 1 is a schematic front elevational view of a plasma display panel according to a preferred embodiment of the present invention, showing the structure thereof;
FIG. 2 is a schematic diagram showing a matrix of electrodes employed in the plasma display panel;
FIG. 3 is an exploded view of a portion of the plasma display panel, showing an array of cells employed therein; and
FIGS. 4A to 4C illustrate the sequence of formation of addressing electrodes employed in the plasma display panel, wherein FIG. 4A is a schematic front elevational view of a substrate, FIG. 4B is a schematic transverse view, on an enlarged scale, of the substrate being exposed to rays of light, and FIG. 4C is a view similar to FIG. 4B , showing the substrate onto which an inking material is jetted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description of the present invention that follows, reference will be made to minimization of a film material used to form electrodes during the manufacture of a plasma display panel (PDP), one of the FPDs which emits light by the effect of gas discharge.
Referring first to FIG. 1 showing, in a schematic representation, the structure of the plasma display panel according to the present invention, the plasma display panel 1 shown therein includes a front substrate structure 10 , which is positioned forwardly of the rear substrate structure 20 with respect to the position of viewers, and a rear substrate structure 20 positioned rearwardly of the front substrate structure 10 . Each of the front and rear substrate structures 10 and 20 is made up of a glass substrate 11 or 21 and at least one panel component both of a size larger than the screen size of the plasma display panel. The front and rear substrate structures 10 and 20 are disposed in face-to-face relation with each other having been placed one above the other and are jointed together with their four-sided peripheral edges sealed by a sealant 35 . A sealed space defined between those substrate structures 10 and 20 is filled with a discharge gas of a kind well known to those skilled in the art.
So far shown in FIG. 1 , the front substrate structure 10 has a width greater than that of the rear substrate structure 20 , so that in an assembled condition in which those substrate structures 10 and 20 are jointed together in the manner described above, the front substrate structure 10 has its left and right portions protruding outwardly from the rear substrate structure 20 . On the other hand, the rear substrate structure 20 has a height greater than that of the front substrate structure 10 , so that in the assembled condition, the rear substrate structure 20 has its upper and lower portions protruding outwardly from the front substrate structure 10 . As is well known to those skilled in the art, those portions of the respective substrate structures 10 and 20 that protrude outwardly as described are used to support thereon a flexible wiring plate (not shown) for electrical connection with an external drive circuit component. It is also well known to those skilled in the art that a surface area of the plasma display panel 1 where cells are arranged represents a screen 60 .
An array of electrodes arranged in a matrix is schematically shown in FIG. 2 . The electrode matrix shown therein has a number of rows occupied by display electrodes X and display (or scanning) electrodes Y for generating display discharges, which extend parallel to each other and alternating with each other, and a number of columns occupied by addressing (or data) electrodes A which extend parallel to each other and perpendicular to the alternating display electrodes X and Y. The neighboring display electrodes X and Y form an electrode pair, and the total number of the electrode pairs shown is equal to the number n of the rows of the electrode matrix. Of the total display electrodes X and Y, the number of which is (n+1), the display electrode X disposed at one of opposite side edges of the electrode matrix and the display electrode Y immediately neighboring such display electrode X are utilized to effect a display at the leading row of the electrode matrix, whereas the display electrode X disposed at the other of the opposite side edges of the electrode matrix and the display electrode Y immediately neighboring such display electrode X are utilized to effect a display at the trailing row of the electrode matrix. The remaining display electrodes X and Y are utilized to effect a display at the neighboring two rows (odd-numbered and even-numbered rows) of the electrode matrix.
The cell structure employed in the plasma display panel is shown in FIG. 3 , in which for facilitating a better understanding the internal structure of the plasma display panel, only a portion of the plasma display panel 1 is shown in an exploded representation with the front and rear substrate structures 10 and 20 separated from each other.
The plasma display panel 1 shown in FIG. 3 is of an AC type having three-electrode surface discharge system. The front substrate structure 10 includes a glass substrate 11 , an array of display electrodes X and Y referred to hereinabove, a dielectric layer 17 and a protective layer 18 . Each of the display electrodes X and Y is made up of a transparent electroconductive film 41 for defining a surface discharge gap and a metal film 42 which is a bus conductor capable of reducing the electric resistance. The transparent electroconductive film 41 is patterned so as to have a generally T-shaped portion for the respective cell.
On the other hand, the rear substrate structure 20 , positioned rearwardly of the front substrate structure 10 , includes a glass substrate 21 , an array of addressing electrodes A referred to hereinabove, a dielectric layer 24 , partition walls 29 and phosphor layers 28 R, 28 G and 28 B. Each of the addressing electrodes A is in the form of a thin straight electroconductive stripe of, for example, 30 μm in width. The partition walls 29 are in the form of a straight rib extending parallel to the respective addressing electrode A and protruding outwardly in a direction substantially perpendicular to the glass substrate 21 and is employed one for each gap between the neighboring addressing electrodes A. When the front and rear substrate structures 10 and 20 are sandwiched together, the partition walls 29 define gas discharge spaces one for each column of the display matrix.
The plasma display panel 1 of the structure described above operates in the following manner. As hereinbefore described, one of the display electrodes, for example, the display electrodes Y are utilized for selecting rows. When an addressing discharge takes place between the scanning electrode and the addressing electrode, addressing is carried out in which wall charge is developed on a surface of the dielectric layer 17 within each of the cells that is to be energized. After the addressing, trains of sustaining pulses of alternating polarities are applied successively to the display electrode pairs so that in response to application of each sustaining pulse, a display discharge in the form of a surface discharge can occur between the display electrodes within the cells to be excited. As a result of the display discharge, the discharge gases filled in the respective discharge spaces emit ultraviolet rays of light which subsequently impinge upon the corresponding phosphor layers 28 R, 28 G and 28 B to excite the latter. It is to be noted that the characters R, G and B affixed to the reference numeral “28” stand for abbreviations of the respective colors, Red, Green and Blue, of light emitter from the phosphor layers when the latter are so excited.
Manufacture of the plasma display panel 1 of the structure discussed above may include a number of processes, i.e., a process of preparing the front and rear substrate structures 10 and 20 separately, a process of integrating the front and rear substrate structures 10 and 20 together with their peripheral edges sealed, and a process of cleaning the internal space and filling the internal space with discharge gases. During the preparation of the rear substrate structure 20 , the addressing electrodes A are formed in the following manner and specifically as discussed in the following examples.
EXAMPLE 1
The addressing electrodes A are formed by the use of an ink jetting process in which an electroconductive inking material is jetted onto a support surface, i.e., the glass substrate 21 , on which the addressing electrodes A are desired to be formed. The electroconductive inking material is in the form of a liquid medium having microparticles of silver (Ag) dispersed therein and also having a viscosity not higher than 20 mPas. Since the glass substrate 21 has no capability of absorbing and, hence, retaining deposits of the inking material on its surfaces as is well known to those skilled in the art, direct jetting of the inking material onto the glass substrate 21 would result in scattering of the jetted inking material to such an extent as to disturb formation of the desired pattern. To enable the pattern of the electrodes to be formed satisfactorily, a surface treatment is carried out to enhance the wettability of at least a surface portion of the glass substrate 21 onto which the inking material is to be jetted.
Referring now to FIGS. 4A to 4C showing the sequence of formation of the addressing electrodes A, a non-polarizing solvent such as, for example, silane coupling or tetradecane, that is known as a surface treating material effective to enhance the wettability with the electroconductive inking material, is printed in a predetermined pattern on the cleansed glass substrate 21 by the use of a screen printing technique or an ink jetting technique or with the use of a dispenser to thereby form undercoats 51 each having a size sufficient to encompass a respective pattern PA of the addressing electrode desired to be formed, as best shown in FIG. 4A . Specifically, each of the undercoats 51 so formed is of a size sufficient to cover the corresponding pattern PA of the addressing electrode, with a side drop of a few micrometers protruding laterally outwardly from the electrode pattern PA over the entire perimeter thereof. Preferably, the side drop is as small as possible, provided that the undercoat 51 can cover the corresponding electrode pattern PA in its entirety and should be determined depending on the accuracy that can be achieved with the screen printing technique.
As compared with the patterning achieved with the photolithography, the pattern printing with the organic material is effective to minimize the amount of the organic material needed and does not require use of any developing material and, therefore, the amount of the indirect material required can advantageously be minimized.
In the next step, the respective patterns of the undercoats 51 are shaped. As best shown in FIG. 4B , the glass substrate 21 bearing the undercoats 51 is placed on an X-Y table 80 capable of undergoing translational motion in two directions perpendicular to each other and is subsequently irradiated with a laser beam to decompose an unnecessary portion of each of the undercoats 51 , i.e., to extinct the capability of enhancing the wettability on that unnecessary portion of each undercoat 51 . Instead, that unnecessary portion of each undercoat 51 may be either removed or modified.
In the illustrated embodiment, for the laser beam, an excimer laser beam may be employed. Also, irradiation of the laser beam is carried out by the use of a light shielding mask 82 having a pattern that is a replica of the electrode pattern PA of the addressing electrodes. In the practice of this Example, the X-Y table 80 is driven to move relative to the incoming laser beam so that each undercoat 51 can be trimmed to a shape coinciding with the corresponding electrode pattern PA of the addressing electrode, leaving the respective trimmed undercoat 52 as shown in FIG. 4B and substantially as shown in FIG. 4C .
It is to be noted that the laser irradiation may be carried out according to the delineating scheme with no mask employed. It is also to be noted that instead of the glass substrate 21 being moved relative to the incoming laser beam as discussed above, the laser beam may be moved, i.e., scanned relative to the glass substrate 21 .
Following the pattern shaping, and as shown in FIG. 4C , an ink jetting device has one or more jetting nozzles 86 placed in face-to-face relation with the respective undercoats 52 on the glass substrate 21 so that while the glass substrate 21 is moved relative to the jetting nozzle 86 in a direction lengthwise of the respective undercoats 52 , the inking material jetted therefrom as indicated by 71 can be deposited on the respective undercoats 52 over the entire length thereof. In so doing, the size of droplets 71 of the inking material jetted from the nozzle 86 must be carefully chosen that deposits of the inking material on the undercoats 52 will not run off the edge of each undercoat 52 .
As a matter of course, the use of the ink jetting device of a type having a plurality of jetting nozzles 86 such as shown in FIG. 4C is effective to maximize the productivity.
The ink jetting referred to above may be carried out cyclically until a desired or required film thickness of the ink deposit can be attained on each of the undercoats 52 . Specifically, since in depositing the inking material each undercoat 52 has a positional selectivity, the deposits of the inking material on the undercoats 52 need not be sufficiently dried for each cycle of jetting of the inking material where the cyclical ink jetting is carried out. In other words, during the cyclic ink jetting, a cycle of ink jetting may be immediately followed by the next succeeding cycle of ink jetting even though the ink deposit formed as a result of the first cycle of ink jetting has not bet been dried sufficiently.
After the formation of the ink deposits of a desired pattern on the respective undercoats 52 , baking is carried out to extinct an organic component contained in the ink deposits, thereby completing formation of the addressing electrodes A made of silver.
EXAMPLE 2
In place of the laser irradiation employed in the foregoing Example 1, a pattern exposure is carried out by the use of an ultraviolet lamp and a photomask to thereby accomplish the pattern shaping in which that unnecessary portion of each undercoat 51 is decomposed as hereinabove described.
EXAMPLE 3
In place of the formation of the ink deposits on the undercoats by the utilization of the ink jetting technique as in the foregoing Example 1, a full surface printing may be carried out with the use of a die coater to deposit the ink droplets 71 on only the undercoats 52 . In such case, the electroconductive inking material is preferably of a kind difficult to deposit on the glass substrate 21 , but alternatively the glass substrate 21 may be surface treated to enhance the ink repellent property prior to formation of the undercoats 52 .
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein. | To enable formation of a pattern of constituent elements, arranged in correspondence with an arrangement of cells in a display region, as desired or required with a minimized quantity of the film material, a method of manufacturing a flat panel display is provided which includes printing on a substrate a surface treating material capable of partially enhancing the wettability of the substrate, in a predetermined pattern sufficient to encompass the eventually formed pattern of constituent elements of the flat panel display. Undercoats made of the surface treating material so printed is then patterned by irradiation of light. Thereafter, utilizing the undercoats, a film material is thereafter selectively deposited on the substrate to thereby complete the predetermined pattern of the constituent elements. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a method for operating a gasification burner/heating boiler installation.
In conventional heating boiler installations, oil burners are used on a large scale. Conventional oil burners of medium rating atomize the heating or fuel oil by means of a nozzle and burn it with excess air in order to minimize the development of soot. However, the atomizing burner output is difficult to control continuously, and then only in a closely defined range. For this reason, atomizing burners for heating boiler installations are operated intermittently so that the average of the output corresponds to the heat demand.
In the operation of conventional atomizing burners, the oil mass flow is given by the viscosity of the heating oil, the cross section of the atomizer nozzle and the oil pressure. The air mass flow is adjusted only when starting the operation and for servicing to the instantaneous value of pressure and temperature of the suction air as a volume flow, and specifically, to so high a value of air excess (λι1.2 to 1.5) that the CO content and the soot number of the exhaust gas do not exceed predetermined limits. Control of the mass ratio between the fuel, i.e., the oil, and air does not take place, so that the combustion air number changes with the viscosity as well as with the H/C and the S/C ratio of the fuel and with the temperature, the pressure and the water vapor content of the drawn-in combustion air in an uncontrolled manner. Along with this uncontrolled change, however, goes the danger of soot formation and a variation of the efficiency.
From U.S. Pat. No. 4,230,443, a continuously controlled gasification or vaporizing burner is known. This burner is based on the principle of two-stage combustion where, in the first stage, heating oil is gasified in a catalytic reactor by partial oxidation with air (gasification or primary air) at air numbers between 0.05 and 0.2 and preferably at about 0.1. The so-obtained product gas, the so-called fuel gas, is then burned stoichiometrically with the remaining air (combustion or secondary air), high combustion temperatures being obtained. The composition of the exhaust gas corresponds substantially to that of the thermodynamic equilibrium at the combustion temperature.
SUMMARY OF THE INVENTION
It is an object of the present invention to operate a gasification burner/heating boiler installation in a controlled manner, i.e., in such a manner that continuous heat output control of a stoichiometric heating oil gasification burner as well as control of the stoichiometry of fuel and air supply becomes possible.
According to the present invention, this and other objects are achieved by the provision that the required burner output is determined from the ambient air temperature; that the mass flows of heating oil and air are controlled as a function of the (demanded) burner output; and that deviations from the stoichiometric ratio between fuel oil and air are controlled by means of a λ-probe arranged in the exhaust gas stream.
In the operation of a heating boiler installation, the required fuel and air mass flow, for constant efficiency of the installation, is directly proportional to heat requirement. The heat requirement, for example, of a residential building, in turn depends, like the forward flow temperature of the boiler, approximately linearly on the ambient or outside air temperature. This relationship is shown schematically in FIG. 1. It can be seen from FIG. 1 that the output requirement varies approximately between 15 and 100% of the burner rating (outside air temperature: +15° to -15° C.).
In the method according to the present invention, the necessary burner output for controlling the heat is, therefore, first determined from the outside air temperature. The corresponding air and heating oil mass flows are adjusted preferably by regulating the speed of a drive which is common for the air compressor and oil pump. The throughput quantities can be set, for example, by performance characteristic control of the speed. Instead of controlling the burner output via speed control of the pump and compressor drive, however, the throughput also can be set for constant speed, advantageously by controlling bypasses to the air compressor and the oil pump.
Deviations from the stoichiometric ratio between fuel and air are leveled out advantageously with the method according to the present invention by changing a bypass to the air compressor or to the oil pump. The control signal is supplied by a so-called lambda-probe arranged in the hot exhaust gas flow.
The heating oil mass flow can further be conveyed by an electrically driven oscillating-piston pump, the throughput being set by performance characteristic control of the frequency and/or of the amplitude of the drive current. Tha air mass flow can then be supplied, for example, by a compressor, the throughput of which is set by performance characteristic control of the speed.
In this case, deviations from the stoichiometric ratio between fuel and air are leveled out by changing the frequency and/or amplitude of the drive current of the oscillating-piston pump or by changing the speed of the compressor or also by changing a bypass to the oil pump and/or to the air compressor. Also here, the lambda-probe supplies the control signal.
A lambda-probe is an oxygen-sensitive electrochemical element which contains a solid electrolyte which conducts oxygen ions at the measuring temperature, and two oxygen-dissolving catalyst electrodes. Such an element generates an electromotive force (EMF) as long as the partial oxygen pressure at the two electrodes is different. If one of the two electrodes is, as in the present case, in contact with the exhaust gas of the burner and the other electrode is in contact with the suction air atmosphere, the EMF increases abruptly during the transition from lean exhaust gas (λ>1) to rich exhaust gas (λ<1). This voltage jump is used in the method according to the present invention for controlling the stoichiometry of the input material mixture. The voltage jump is limited during the transition to the rich exhaust gas by the fact that the electrochemical element then acts as a fuel cell due to the combustible components which then occur in the exhaust gas.
In the method according to the present invention, the lambda-probe is preferably arranged in the fire box of the heating boiler, at least partially. This ensures that the minimum operating temperature, and thereby the operability of the probe, is assured under all operating conditions.
The method according to the present invention has in particular the advantage that due to the use of a lambda-probe, the control of the stoichiometry of the input material mixture is independent of the temperature, the pressure and the water vapor content of the suction air and also independent of the viscosity as well as the H/C and S/C ratio of the heating oil. Therefore, neither the danger of soot formation nor a variation of the efficiency is present. In addition, this method, due to the use of a gasification or vaporizing burner, offers the safety of heating oil storage as well as the advantages of gas operation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph showing the relationship between boiler water temperature and heat output of the heating boiler installation.
FIG. 2 schematically shows the control and regulation arrangement to the method of the present invention with reference to an embodiment of a gasification arrangement.
FIG. 3 is a cross-sectional view of a preferred embodiment of the gasification burner used with the method according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the fire box 11 of the heating boiler 10, a gasification burner 12 is arranged. Through a line 13, fuel in the form of heating oil is fed to the burner 12 and air is fed through a line 14. For transporting the fuel serves a pump 15, and for feeding-in the air, a compressor 16. The oil pump 15 and the air compressor 16 are mounted together on the drive shaft 17 of a motor 18. In the fuel feed line 13 is arranged as a bypass to the pump 15 a line 19 with a valve 20, and in the air feed line 14, as a bypass to the compressor 16, a line 21 with a valve 22. Flow-wise downstream from the shunt 21, i.e., between the compressor 16 and the burner 12, a valve 23 is arranged in the air feed line 14 and divides the total air stream into gasification air and combustion air, which are fed to the burner 12 separately via lines 24 and 25.
In the water loop 26 of the heating boiler 10, a circulating pump 27 is arranged; the load, i.e., the user, is designated with the numeral 28. The lambda-probe 30 is exposed to the exhaust gas stream of the burner 12; it can, therefore, be arranged, for example, in the exhaust gas pipe 29 of the heating boiler 10.
In the operation of the gasification burner/heating boiler installation, the outside air temperature is determined by a sensor 31 and the outgoing boiler temperature by a sensor 32, and is transmitted to a control and regulating unit 35 via lines 33 and 34, respectively. The signal of the lambda-probe 30 is fed to the control and regulating unit 35 via a line 36.
The speed of the motor 18 is controlled by the control and regulating unit 35 via a line 37, whereby the flow of fuel and air is controlled as a function of the burner output. From the control and regulating unit 35 a line 38 further leads to the valve 20 (in the bypass line 19 of the fuel feed line 13), and a line 39 leads to the valve 22 (in the bypass line 21 of the air feed line 14). Deviations from the stoichiometric ratio between fuel and air can then be controlled by operating the valves 20 and 22. Finally, a line 40 further leads from the control and regulating unit 35 to valve 23 in the air feed line 14. The ratio between gasification air and combustion air, which in general is 1:9, can be adjusted by the valve 23.
In FIG. 3, a preferred embodiment of the gasification burner used with the method according to the present invention is shown (see DE-OS No. 28 41 105).
The gasification burner 50 consists essentially of two stages, a gasification part 51 with a centrally arranged reactor chamber 53 which contains a catalyst, and a combustion part 52 which comprises a mixing chamber 54, an ignition chamber 55 and a combustion chamber 56. The reaction chamber and the catalysis device 53, respectively, are preceded by an ante-chamber 57 for mixing the fuel with gasification air. To this end, the gasification air is fed to the ante-chamber 57 from a so-called ring or annular space 58 through radial ducts or canals 59 which connect the ante-chamber to the ring space 58 (which is separated from the ante-chamber by a ring wall), and is mixed with the fuel at a homogenizing device 60, for example, a twisting orifice provided with inclined slots. In the ring space 58, to which the gasification air is fed via an inlet 61, a source of heat 62 is provided for preheating the air upon starting the burner and in the case of load changes. To feed the fuel to the ante-chamber 57, the latter is preceded by a so-called front chamber 63 which merges into a ring canal 64. The ring canal 64, to which the fuel is fed via a line 65 is provided with a source of heat 66 for evaporating the liquid fuel during the starting process.
In the reactor chamber 53, the fuel is converted by partial oxidation into a fuel gas which is fed to the mixing chamber 54 and is mixed there at a homogenizing device 67, for example, a twisting orifice provided with inclined slots, with the combustion air. The combustion air is fed to the mixing chamber 54 through an inlet 68. The fuel gas/combustion air mixture enters the ignition chamber 55 from the mixing chamber 54 through a perforated disc 69 serving as backfire protection, and from there through a so-called perforated wall 70 into the combustion chamber 56 which is closed off from the outside by a gas-permeable burner plate 71. When flowing through the ignition chamber 55 into which an ignition electrode 72 projects, and through the combustion chamber 56 especially when passing through the perforated wall 70 and the burner plate 71, both of which are also called flame plates, the fuel gas/combustion air mixture burns up and then passes as exhaust gas into the interior of the heating boiler, i.e., the fire box (see also FIG. 2, numeral 11), where it serves for heating the boiler water.
In the method according to the present invention, it has been found to be advantageous, as already described, to arrange the lambda-probe in the fire box of the heating boiler, since satisfactory operation of the lambda-probe is obtained only at temperatures above about 300° C. The lambda-probe is, therefore, attached preferably in the fire box in the vicinity of the last flame plate, i.e., the so-called burner plate (see FIG. 3, numeral 71). If this is not possible for space reasons, the operating temperature of the lambda-probe can advantageously also be maintained by an electric heater.
It is a further prerequisite for proper control that, with a stoichiometric input material mixture, no free oxygen is measured in the exhaust gas, as may be the case, when a high-temperature equilibrium is "frozen." In order to fulfil these conditions, the thermodynamic equilibrium must be adjusted in the measuring gas at temperatures so low that practically only CO 2 and H 2 O occur as combustion products. This is the case at temperatures between about 300 to 1000° C. and preferably at about 500° C. if the measuring gas is fed to the measuring electrode of the lambda-probe via a catalyst which adjusts the low-temperature equilibrium, or if the electrode material itself adjusts the low-temperature equilibrium. Such catalysts or electrode materials are, for example, platinum and rhodium. | The invention relates to a method for operating a gasification (or vaporizing) burner/heating boiler installation and has the objective to develop such an installation in such a manner that it can be operated controllably. According to the invention, the required burner output is determined for this purpose from the outside air temperature, and then the mass flows of the heating oil and the air are controlled as a function of the demanded burner output, deviations from the stoichiometric ratio between the heating oil and the air being leveled-out by means of a lambda-probe arranged in the exhaust gas stream. | 5 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a portable power source, particularly, to a portable power source using a fuel cell.
(2) Description of Related Art
Since phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), and solid oxide fuel cells (SOFC) convert chemical energy of supplied gas into electric energy, they retain superior efficiency in the generation of electricity. The fuel cells with capacity of 100 W to 100 kW are already in practical use, and particularly, the compact fuel cells are used as a power source for apparatus in outside transmissions, the civil engineering and construction, or the like.
Conventional power sources using compact fuel cells have a number of air inlets and a number of reactant gas outlets on the several surfaces of the cases enclosing the fuel cells, from which the air leaks into the cases when the power sources are not in use. Then electrolyte of the fuel cells(for instance, phosphoric acid) absorbs water in the air, deteriorating its concentration and therefore, cell characteristics. Accordingly, valves are formed at the inlets and outlets in order to shut off the air, even though satisfactory results are not obtained. In addition, forming the valves makes the construction of the power sources more complicated as well as adding weight thereto, which makes them unfavorable for portable ones.
SUMMARY OF THE INVENTION
The present invention has an object to provide a light-weight portable power source with simple construction and capable of preventing the air leakage thereinto.
The object is fulfilled by a portable power source which comprises a fuel cell generating electricity using hydrogen as fuel, a hydrogen storage unit filled with hydrogen absorbing alloy for supplying hydrogen to the fuel cell, a case enclosing the fuel cell and hydrogen storage unit, a lid for sealing a part of the case when the portable power source is not in use, wherein the lid seals a surface of the case on which at least one air inlet for taking in the air necessary for the fuel cell to generate electricity and a reactant gas outlet for exhausting reactant gas produced by the generation of electricity are formed.
Sealing the air inlet and reactant gas outlet formed on the case with the lid prevents the air leakage thereinto when the portable power source is not in use. Therefore, the electrolyte concentration as well as cell characteristics will not be deteriorated.
The portable power source further comprises an air inlet duct between the air inlet and the fuel cell, and an exhaust duct between the fuel cell and the reactant gas outlet, wherein a part of the internal surface of the case also serves as a part of the inlet duct and that of the exhaust duct.
The above construction can reduce parts for the inlet duct and exhaust duct, contributing to the lightening of the portable power source.
The hydrogen storage unit may be placed in the exhaust duct.
Although the temperature of the hydrogen storage unit falls in the course of the hydrogen supply, the above construction enables it to maintain an operatable temperature by being heated with the reactant heat carried by the reactant gas flowing through the exhaust duct.
The lid may seal a surface of the case on which a control panel for controlling the operation of the power source is placed.
With the above construction, misoperation can be prevented by covering the control panel with the lid.
The hydrogen storage unit may include cylinders filled with hydrogen absorbing alloy as well as a pan for collecting condensate running down from the surfaces thereof
The temperature of the cylinders falls due to the hydrogen supply, during which water in the reactant gas condensates on the surfaces of the cylinders; however, the pan collects substantially all of the condensate, preventing the spill of the condensate inside the case, and therefore, preventing deterioration in electrolyte concentration as well as cell characteristics.
An absorber may be placed on the pan for absorbing the condensate running down from the surfaces thereof.
The absorption of the condensate by the absorber prevents the condensate from spilling inside the case even when the hydrogen storage unit is removed from the power source.
The hydrogen storage unit may include cylinders filled with hydrogen absorbing alloy as well as the absorber for absorbing the condensate running down from the surfaces thereof.
Forming the absorber on the hydrogen storage unit can prevent deterioration in electrolyte concentration and cell characteristics.
The case may include clamps for sealing the case with the lid, and a sealing member may be placed on the edge of the case where the lid fits therewith so as to encircle the edge, thereby further ensuring sealing effect.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrates specific embodiments of the invention In the drawings:
FIG. 1 is a cross section of the main part of a power source of the present invention;
FIG. 2 is an X--X transverse cross section of FIG. 1;
FIG. 3 is an enlargement showing a packing of the power source; and
FIG. 4 is a cross section of the main part of another power source of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment I
As shown in FIGS. 1 and 2, the portable power source of the present invention comprises a case 1 and a lid 2 made from light metal such as aluminum or DURALUMIN (an aluminum alloy containing copper, magnesium, and magnanese in a ratio, respectively, of 95:4:0.5:0.5). The case 1 encloses a fuel cell 3 (for instance, a phosphoric acid fuel cell), a hydrogen storage unit 4 for supplying hydrogen to the fuel cell 3 during the operation, a control unit 5, a DC-DC converter 6 for maintaining constant electromotive force produced by the generation of electricity, a catalytic burner 7 filled with platinum catalyst, a start-up heater 8, a fuse relay box 9, and air supply fans 10 and 11. The hydrogen storage unit 4 includes a number of cylinders filled with hydrogen absorbing alloy. The start-up heater 8 and air supply fans 10 and 11 are driven on the electricity generated by the fuel cell 3. The start-up heater 8 heats up the fuel cell 3 to its operation temperature, approximately 100° C. The catalytic burner 7 consumes unreacted hydrogen released from the fuel cell 3 with the air from the air supply fan 11 by catalytic combustion so that no unreacted hydrogen will be released to the atmosphere. What controls the portable power source is the control unit 5, and for instance, it controls a rotating speed of the air supply fan 11 in order to adjust the air supply to the catalytic burner 7, or it controls the operation of the start-up heater 8 like making it stop heating up the fuel cell 3 at the operation temperature thereof.
Most of the air taken in from air inlets 12 with the operation of the air supply fan 10 flows directly into the fuel cell 3 for the generation of electricity, and the remains flow into the fuel cell 3 after having flown around the control unit 5, DC-DC converter 6, and the like so that they cool these devices. The high-temperature reactant gas carrying the heat of reaction produced in the fuel cell 3 is released to the atmosphere through a reactant gas outlet 13 while heating up the hydrogen storage unit 4 placed on the way. A part of the internal surface of the case 1 also serves as a part of an air inlet duct between the air inlet 12 and the fuel cell 3 and that of an exhaust duct between the fuel cell 3 and the reactant gas outlet 13, contributing to lightening of the portable power source.
The upper part of the case is a truncated pyramid. The air inlet 12, another air inlet(not shown), reactant gas outlet 13, and connectors 15 are formed on each side surface thereof, respectively, wherein the side surface having the air inlet 12 and that having another air inlet oppose each other. A control panel 14 is placed on the top, which includes a lamp indicating a hydrogen remaining pressure, a switch for adjusting the hydrogen pressure, an switch for opening/shutting a valve when supplying hydrogen or the like(not shown). As shown in FIG. 3, a packing 16 is placed on the edge of the base of the truncated pyramid where the edge of the lid 2 fits so as to encircle the edge, in order to further ensure the sealing effect.
The case 1 and lid 2 are sealed together with clamps 17 in a way that the lid 2 covers the truncated pyramid, and with a handle formed on the top of the lid 2, the case, or the portable power source, can be easily carried to desired places.
The operation of the portable power source is described hereunder with referring to FIGS. 1 and 2, wherein an arrow A indicates the air flow and an arrow B indicates the reactant gas flow produced by the fuel cell 3 during the generation of electricity.
After the removal of the lid 2, the valve of the hydrogen storage unit 4 is opened by the switch on the control panel. Then with the remaining(unconsumed) air and hydrogen supplied from the hydrogen storage unit 4, the fuel cell 3 pre-generates electricity, which drives the air supply fan 10. With the operation of the air supply fan 10, the air is taken in from the air inlets 12 to the fuel cell 3, and the fuel cell 3 accordingly starts the generation of electricity. During the operation, the temperature of the fuel cell 3 rises by the heat of reaction from the generation, while that of the hydrogen storage unit 4 falls in the course of the hydrogen supply to the fuel cell 3. If the temperature of the latter continues to fall, it becomes incapable of supplying hydrogen, bringing deterioration in the generation. However, the high-temperature reactant gas transfers the heat of reaction it carries to the hydrogen storage unit 4 while flowing around thereof, thus enabling it to maintain the operatable temperature. On the other hand, although the control unit 5, DC-DC converter 6, and the like are gradually heated by the radiation from the fuel cell 3, the air from the air inlets 12 cools these devices while flowing around thereof.
As a result, smooth and sustainable generation of electricity is realized with the portable power source.
Although the air inlets 12, the reactant gas outlet 13 and the control panel 14 are formed on the upper surface of the case 1, they can be formed at any side surface thereof, provided that the lid 2 covers all of the aforementioned airtight.
The phosphoric acid fuel cell is used in the embodiment, however, one of the solid oxide fuel cells which is capable of operating at the lower temperature is also applicable.
Embodiment II
As shown in FIG. 4, it has the same construction as Embodiment I except that the hydrogen storage unit 4 includes a pan 42. Hereinafter, like components are labeled with like reference numerals with respect to Embodiment I, and the description of these components is not repeated.
The hydrogen storage unit 4 having a number of cylinders 41 includes the pan 42 at the bottom, which includes an absorber 42a(for instance, Form 4S, a copolymer of acrylic acid and sodium salt acrylate, Sumitomo Seika Chemicals Co., Ltd.).
As previously mentioned, the temperature of the hydrogen storage unit 4 falls in the course of the hydrogen supply, and the high-temperature reactant gas from the fuel cell 3 helps it to maintain its operatable temperature, during which the water in the reactant gas condenses on the surfaces of the cylinders 41 when it touches them. However, substantially all of the condensate running down therefrom is collected into the pan 42, and further, absorbed into the absorber 42a, making it possible to prevent the electrolyte of the fuel cell 3 from absorbing the condensate, therefore, deterioration in cell characteristics.
With the above construction, the condensate is removed easily by taking out the hydrogen storage unit 4 from the case 1 in stead of wiping off with a cloth or tissue papers. Moreover the absorption by the absorber 42a prevents the condensate from spilling inside the case 1 even when the portable power source is placed on a tilt. When the absorber 42a has come to its full capacity; capacity can be easily restored by replacing it with a new absorber.
Adding the pan 42 and absorber 42a to the portable power source does not affect its portability. Table 1 shows an operation condition of the portable power source, under which 3 g/min of high-temperature vapor is produced, meaning that less than 3 g/min, or less than 180 g/hr condensate is produced. Since the capacity of the absorber 42a is 200 to 600 g/g, only 1 g of the absorber 42a with the volume of 1.05-1.33 ml/g (bulk density of 0.75-0.95 g/ml) is enough for one hour operation of the portable power source.
TABLE 1______________________________________DC output capacity (Wh) 250(250W × 1 hour)______________________________________Output voltage (V) 12Output current (A) 21______________________________________
It should be noted that the above construction enables the portable power source to maintain the portability as well as a constant electrolyte concentration by preventing the condensate from spilling inside the case 1, therefore deterioration in cell characteristics.
Remarks
The absorber 42a are formed in the pan 42, however, it can be formed on the hydrogen storage unit 4.
As the absorber 42a, Form 10 SH-NF, Form EP, Form ET (copolymers of acryic acid and sodium salt acrylate, Sumitomo Seika Chemical Co., Ltd.) or the like are also applicable.
The absorber 42a is not a must, however, it is preferable to have it in order to enhance reliability in preventing the spill of the condensate inside the case 1.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein. | The present invention provides a portable power source comprising a fuel cell generating electricity using hydrogen as fuel, a hydrogen storage unit filled with hydrogen absorbing alloy for supplying hydrogen to the fuel cell, a case enclosing the fuel cell and hydrogen storage unit, and a lid for sealing a part of the case when the portable power source is not in use, wherein the lid seals a surface of the case on which at least one air inlet for taking in the air necessary for the fuel cell to generate electricity and a reactant gas outlet for exhausting reactant gas produced by the generation of electricity are formed. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to a heat sink, in particular to a heat sink, a heat sink system having a heat sink and the heat sinking method for the same.
2. Description of Prior Art
Since the invention, computers have become indispensible part of everyday life. Various computers are developed to meet all kinds of demands by users, such as personal computer (PC), notebook (or referred as laptop) or barebones. Among which, notebooks became popular immediately when the product was introduced in the beginning as a result of the easy to carry feature the notebook delivers. Up-to-date, notebook remains the favorite computer category of users.
With the advance of the technology and semiconductor industry, the hardware operating capability is increasing and processing speed becomes faster and faster. At the same time, the heat generated from continuous high speed processing of the hardware also increases. Ordinary personal computer has casing of much larger dimensions which provides spacious space inside the casing. Sufficient space provides better heat sinking performance and allows designs to add one or more heat sink fans or heat sink fins in the casing for offering better heat sinking capacity for hardware components generating more heat such as a CPU (Central Process Unit, CPU), a graphic card and a memory. Though, ordinary notebook is designed by weight and dimension within a certain range in order to be easy to carry for users. As a result, the space free for installing additional heat sink fans or heat sink fins is insufficient. Frequently, a notebook becomes hot or very hot to the touch on its body (in particular the bottom of the notebook). Under the circumstance, operation of the notebook hardware starts to slow down due to excess heat left unattended. In the worst case, the hardware may be burnt by the heat.
To address the above problem, many heat sink pads for heat sinking the heat generated by a notebook are introduced in the market. Refer to FIG. 1 , FIG. 1 is a solid diagram of a prior art heat sink. A heat sink pad 10 shown in the FIG. 1 has a base made by heat sinking materials (such as aluminum). When a notebook (not shown) is placed on the heat sink pad 10 , the bottom of the notebook directly contacts with the surface of the heat sink pad 10 surface 11 where the materials of the heat sink pad perform heat sinking by thermal conduction. Further, the heat sink pad 10 has a switch 12 , and installs one or more fans 13 on the bottom of the surface 11 . When a power wire 14 is connected to the heat sink pad 10 for powering the heat sink pad 10 , heat sinking capability of the heat sink pad 10 is enhanced following the fan 13 is powered ON by the switch 12 .
However, the traditional heat sink pad 10 mentioned above has at least the following disadvantages:
1. It is required to manually switch the switch 12 to trigger power ON or power OFF of the fan 13 . If the switch 12 is not switched to power ON, the heat sink pad 10 does not perform heat sinking and fails its function. Also, if the switch 12 is not switched to power OFF, the fan 13 continues to operate and creates unnecessary power consumption.
2. The rotation speed of the fan 13 is fixed and does not change in respond to the concurrent temperature of a notebook. Therefore the heat sinking performance is limited.
To address the above problems, a novel system and a method are proposed by the inventor to improve the above problems for increasing the heat sinking performance of a heat sink pad or a heat sink and further enhanced the operation safety of using a notebook.
SUMMARY OF THE INVENTION
The objective of the present invention is to provide a heat sink having auto switching function, heat sink system and the heat sinking method for the same. The heat sink receives a control command sent by an external device as a result of temperature changes for auto controlling operations of a heat sink device according to temperature status of an external device.
To achieve the above objective, a notebook and a heat sink are connected according to the present invention. The temperature of the notebook is detected via a temperature sensing device. When the temperature of the notebook reaches a threshold value, a control command is sent to the heat sink. The heat sink controls a heat sink device according to control command for controlling power ON or power OFF of a thermoelectric cooler of the heat sink device, or to control power ON, power OFF, or change rotation speed setting of a heat sink fan in the heat sink device.
Compare to prior art, the present invention delivers the following advantages. According to the present invention, it is not required to install a switch in a heat sink, neither to manually switch operation mode by a user. The thermoelectric cooler and heat sink fan in a heat sink device directly auto powered ON or powered OFF according to the temperature of the notebook. Thus, unnecessary electricity waste is eliminated when a user forgets to turn off switch circuit mindlessly. Further, if the temperature of a notebook continues to increase or decrease, the rotation speed of the heat sink fan is changed automatically according to the temperature status change of the notebook so as to optimize the heat sinking performance of the heat sink.
BRIEF DESCRIPTION OF DRAWING
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a solid diagram of a prior art heat sink;
FIG. 2 is a block diagram of a preferred embodiment of the present invention;
FIG. 3 is a solid diagram of a preferred embodiment of a hint sink according to the present invention;
FIG. 4 is a connection schematic diagram of a preferred embodiment of the present invention;
FIG. 5 is a flow chart of a preferred embodiment of the present invention;
FIG. 6 is a block diagram of another preferred embodiment of the present invention; and
FIG. 7 is a connection schematic diagram of another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to a preferable embodiment, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.
FIG. 2 is a block diagram of a preferred embodiment of the present invention. As shown in FIG. 2 , heat sink system of the present invention mainly has a notebook 2 and a heat sink 3 . The notebook 2 (referred as the computer 2 in the following) mainly comprises a Central Processing Unit (CPU) 21 , a temperature sensing device 22 and a transmitting-end Universal Serial Bus (USB) data transmission wiring 23 . The temperature sensing device 22 is disposed on the internal hardware components of the computer 2 , such as a main board, a memory or the CPU 21 for detecting temperature of the above hardware temperature. The CPU 21 is electrically connected to the temperature sensing device 22 for receiving detected data reported by the temperature sensing device 22 in order to generate a control command C 1 . The transmitting-end USB data transmission wiring 23 is electrically connected to the CPU 21 for receiving the control command C 1 and performing external data transmission.
A driver 24 is installed in the computer 2 and executed by the computer 2 . The driver 24 makes determination according to the detected data reported by the temperature sensing device 22 for driving the CPU 21 to generate the corresponding control command C 1 (detailed in the following).
The heat sink 3 mainly comprises a control unit 31 , a receiving-end USB data transmission wire 32 and one or more heat sink devices 33 . The heat sink 3 connects with the computer 2 via the receiving-end USB data transmission wire 32 for receiving the external control command C 1 , wherein the receiving-end USB data transmission wire 32 is connected to the transmitting-end USB data transmission wiring 23 via a USB transmission cable L 1 , but the scope of the invention is not limited to the embodiment. The control unit 31 is electrically connected to the receiving-end USB data transmission wire 32 and the heat sink device 33 for receiving the control command C 1 and controlling operations of the heat sink device 33 according to the content of the control command C 1 . It should be noted that, the transmitting-end USB data transmission wiring 23 and the receiving-end USB data transmission wire 32 can be complete USB transmission interfaces or connectors required in the data transmission for transmitting the control command C 1 .
FIG. 3 and FIG. 4 are solid diagram and connection schematic diagram of a heat sink of a preferred embodiment according to the present invention. The heat sink 3 has a base 30 made by materials with better thermal conductivity such as aluminum or copper etc. The control unit 31 , the receiving-end USB data transmission wire 32 and the heat sink device 33 are disposed in the base 30 , wherein the connector of the receiving-end USB data transmission wire 32 is exposed on the base 30 for connecting the USB transmission cable L 1 and the transmitting-end USB data transmission wiring 23 .
If the transmitting-end USB data transmission wiring 23 and the receiving-end USB data transmission wire 32 are complete USB transmission interfaces, the heat sink 3 receives power from the computer 2 via the connection for powering the control unit 31 and the heat sink device 33 . Further, the heat sink 3 further comprises a power supply 34 , such as a battery or a power wire connected to a wall power socket, disposed in the base 30 and is electrically connected to the control unit 31 and the heat sink device 33 for offering additional power to the control unit 31 and the heat sink device 33 .
The heat sink device 33 mainly comprises a thermoelectric cooler 331 , a heat sink fan 332 and a heat sink body 333 , wherein the thermoelectric cooler 331 preferably is a thermal cooling circuit and has corresponding a cool end surface 3311 and a hot end surface 3312 . The cool end surface 3311 is attached to the bottom surface of the base 30 . The hot end surface 3312 and the heat sink body 333 are laminated. The heat sink device 33 is powered on to trigger operation of the cool end surface 3311 of the thermoelectric cooler 331 for reducing the temperature evenly across the surface of the base 30 via thermal conduction. Thus, when the computer 2 is disposed on the base 30 , the excess heat generated by the computer 2 is conducted to the cool end surface 3311 via the surface of the base 30 . The heat sink body 333 is attached to the hot end surface 3312 to facilitate heat sinking on the hot end surface 3312 . When the heat sink fan 332 is power ON, the hot air accumulated above the heat sink body 333 is ventilated via the heat sink fan 332 and evacuated from the a heat dissipation pore 334 at on end of the heat sink device 33 a to achieve the optimized heat sinking.
FIG. 5 is a flow chart of a preferred embodiment of the present invention. The heat sinking method of the present invention comprises steps in the following. The notebook 2 detects internal temperature status of the notebook 2 (step S 1 ). Following that, the heat sink 3 auto controls the operations of the heat sink device 33 according to the temperature of the notebook (step S 3 ). The detailed steps are explained in the following, wherein step S 1 further comprises sub-steps S 10 ˜S 20 , and step S 3 further comprises sub-steps S 30 ˜S 36 .
Firstly, the computer 2 detects internal temperature of the computer 2 via the temperature sensing device 22 (step S 10 ), and the temperature sensing device 22 reports the detected data after detecting the temperature (step S 12 ). Following that, the driver 24 makes a determination according to the reporting detected data (step S 14 ). The determination is made mainly for determining if the internal temperature of the computer 2 reaches a threshold value required to send a control command C 1 (step S 16 ). In step S 16 , if the result is no, then the process moves back to step S 10 , the temperature sensing device 22 continues to detect the temperature of the computer 2 ; if the result is yes in step S 16 , then the driver 24 drives the CPU 21 to generate the corresponding control command C 1 (step S 18 ).
As mentioned above, for example, when the heat sink device 33 is powered OFF and the temperature of the computer 2 exceeds a first threshold value, the driver 24 drives the CPU 21 to send the control command C 1 for powering ON the heat sink device 33 (i.e. powering ON the thermoelectric cooler 331 or/and the heat sink fan 332 ).
In another example, when the heat sink fan 332 is powered ON and the temperature of the computer 2 exceeds a second threshold value, the CPU 21 sends the control command C 1 to increase the rotation speed of the heat sink fan 332 . When the heat sink fan 332 is powered ON and the temperature of the computer 2 is below a third threshold value, the CPU 21 sends the control command C 1 to decrease the rotation speed of the heat sink fan 332 . When the thermoelectric cooler 331 or/and the heat sink fan 332 are powered ON and the temperature of the computer 2 is smaller than a fourth threshold value, the CPU 21 sends a control command C 1 to power OFF the thermoelectric cooler 331 or/and the heat sink fan 332 . Among these steps, the first threshold value is lower than the second threshold value, the fourth threshold value is lowered than the third threshold value, and the first threshold value is approximately the same with the fourth threshold value which is the reference temperature to power ON/OFF the thermoelectric cooler 332 or/and the heat sink fan 332 , the second threshold value is approximately the same with the third threshold value which is the reference temperature to increase/decrease rotation speed of the heat sink fan 332 . Nonetheless, the above is another preferred embodiment of the present invention and is not used to limit the scope of the invention.
Lastly, when the CPU 21 generates the control command C 1 in step S 18 , the computer 2 externally transmits the control command C 1 via the transmitting-end USB data transmission wiring 23 (step S 20 ).
Following step S 20 , the heat sink 3 receives the control command C 1 output by the computer 2 via the receiving-end USB data transmission wire 32 (step S 30 ). Following that, the control unit 31 operations of the control the heat sink device 33 according to content of the control command C 1 (step S 32 ). Lastly, the thermoelectric cooler 331 is powered ON or powered OFF under the control by the control unit 31 (step S 34 ) and the heat sink fan 332 is powered ON, powered OFF or change rotation speed under the control by the control unit 31 (step S 36 ).
FIG. 6 and FIG. 7 are block diagram and connection schematic diagram of a preferred embodiment of the present invention. It should be noted that, the receiving-end USB data transmission wire 32 in the heat sink 3 may be implemented via a Bluetooth transmission interface 32 ′. Further, the receiving-end USB data transmission wire 32 and the Bluetooth transmission interface 32 ′ are both implemented in a heat sink. Users of the heat sink 3 are allowed to decide to connect the computer 2 and the heat sink 3 via a USB transmission interface or a Bluetooth transmission interface. The Bluetooth transmission interface 32 ′ is electrically connected to the control unit 31 . The computer 2 connects to an external Bluetooth transmission module 4 (such as the Bluetooth transmission module 4 using USB transmission interface in FIG. 7 ) via the transmitting-end USB data transmission wiring 23 so as to interconnect with the Bluetooth transmission interface 32 ′ in the heat sink 3 via wireless link for wirelessly transmitting the control command C 1 .
As the embodiment mentioned above, the computer 2 transmit the control command C 1 to the Bluetooth transmission module 4 via the transmitting-end USB data transmission wiring 23 , then externally and wirelessly transmits the control command C 1 via the Bluetooth transmission module 4 in step S 20 . In step S 30 , the heat sink 3 wirelessly receives the control command C 1 via the Bluetooth transmission interface 32 ′. Nonetheless, the above is another preferred embodiment of the present invention and is not used to limit the scope of the invention. Any transmission interface for transmitting a command is applicable to the present invention.
As the skilled person will appreciate, various changes and modifications can be made to the described embodiments. It is intended to include all such variations, modifications and equivalents which fall within the scope of the invention, as defined in the accompanying claims. | A heat sink having auto switching function, a heat sink system and a heat sinking method are disclosed. The heat sink receives a control command sent by an external device. An internal heat sink device is controlled according to content of the control command to control power ON or power OFF of a thermoelectric cooler of the heat sink device or to control power ON, power OFF, or change rotation speed setting of a heat sink fan in the heat sink device. Thus, the heat sink auto switches operations of the heat sink device correspondingly according to temperature changes of the external device. | 8 |
This is a division of patent application Ser. No. 712,702 filed Aug. 9, 1976, now U.S. Pat. No. 4,104,178, which was a continuation of patent application Ser. No. 625,592, filed Nov. 24, 1975, now U.S. Pat. No. 3,983,042.
BACKGROUND OF THE INVENTION
Forging is a process by which the shape and physical properties of metal can be changed. The process involves placing a piece of metal (normally heated) between the halves of a die and forcing the die to close by impact or pressure. The operation causes a controlled plastic deformation of the metal into the cavities of the die. This flow of material results not only in a change in shape of the metal but also increases the density and uniformity of the metal, improves its grain structure, and causes a shape-conforming grain flow. The resulting workpiece has properties which are superior to those generated by other methods, making forging essential where high performance workpieces are required.
One of the critical components of a forging system is the lubricant which separates the die from the workpiece. As with all lubricating situations, it is essential that this lubricant be effective to minimize wear of the extremely expensive forging dies and minimize expenditure of energy over a wide range and condition. Somewhat peculiar to the forging process, however, is that merely maximizing lubricity is not the only goal, since a certain degree of friction between the workpiece and die is essential to optimize the properties of the workpiece. This controlled lubricity is particularly important when it is necessary to fill deep impression dies.
As modern demand for safer and more dependable machine structures increases, the forging art is being applied to more difficult materials, at higher temperatures and pressures to form more complex shapes. Although oil-based lubricating compositions, which are effective under these extreme conditions, have been developed, their properties are found to conflict seriously with national commitments to personal safety and protection of the environment. The oil-based lubricants are normally flammable and can ignite well below common operating temperatures. Normal operation results in billowing carbonaceous smoke which is unpleasant and sometimes toxic. Furthermore, cleaning of the workpieces and dies requires solvent washes that produce large quantities of rinse which, because of the economics of recycling, and desire to protect the environment can present serious disposal problems.
Attempts at avoiding the problems inherent in the use of oil-based lubricants have generally been directed toward water-based compositions. Early attempts, involving mixtures of graphite, clay minerals, and molybdenum disulfide, were found ineffective, because they did not sufficiently wet the hot metal surfaces to provide lubrication. They were also unacceptable due to the corrosion caused by the high temperature break-up of the components. Additives and substitutions which solved one problem often created another. For example, the addition of soaps to improve wetting often caused caking in cavities and increased smoke production and odor. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a forging lubricant which effectively reduces the die wear and energy requirement of a forging operation.
Another object of this invention is the provision of a forging lubricant which produces an extremely low amount of air pollution.
A further object of the present invention is the provision of a forging lubricant which is simple and easy to produce and which, in use, leads to relatively less expense in overall operating costs.
It is another object of the instant invention to provide a forging lubricant which has a long storage life and is not adversely effected by reasonable storage conditions.
A still further object of the invention is the provision of a forging lubricant which is simple and safe to apply to the dies using spray equipment.
It is a further object of the invention to provide a forging lubricant which is virtually non-flamable and does not give off undesirable vapors or corrosive byproducts during use.
It is a still further object of the present invention to provide a forging lubricant which has the proper combination of lubricating properties to allow predictable and effective operation of forging technique over wide ranges of workpiece shape, temperature, pressure and material.
Another object of the invention is the provision of a forging lubricant which has adequate insulating properties to prevent undesirable cooling of the workpiece by the dies.
Another object of the invention is the provision of a forging lubricant which effectively prevents workpieces from sticking in the dies after the forging operation.
Another object of the invention is the provision of a forging lubricant which is easily cleaned from the workpiece and dies, and which results in a rinse which can be easily cleaned to avoid pollution.
With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of steps and the details of the composition hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.
SUMMARY OF THE INVENTION
This invention involves a water-based lubricant for hot forging metal. The composition is virtually non-flammable and non-polluting. It comprises water, graphite, an organic thickener, sodium molybdate, and sodium pentaborate. Other additives are sodium bicarbonate and ethylene glycol, or mica.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The water-based lubricant of the present invention is exemplified by the following preferred composition. Unless otherwise noted, compositions are expressed in percent of total weight.
EXAMPLE 1
______________________________________ Weights Weight For % 50 Gallons______________________________________Sodium carboxymethylcellulose (CMC) 0.77 4 Lbs.Aqueous 30% graphite suspension(Quaker LQ-405 or Acheson 147) 38.60 200 Lbs.Sodium molybdate 5.0 26 Lbs.Sodium pentaborate 3.18 16.5 Lbs.Sodium bicarbonate 4.83 25 Lbs.Ethylene glycol 9.02 46.6 Lbs.Water 38.60 200 Lbs. 100.00 518.1 Lbs.______________________________________
To prepare 50 gallons of the mixture, dissolve 4 lbs. of CMC in 16 gallons (133.34 lbs.) of water and mix thoroughly. Then, dissolve 26 lbs. sodium molybdate and 16.5 lbs. of sodium pentaborate in same container. Add 200 lbs. of 30% graphite and stir. Dissolve 25 lbs. of sodium bicarbonate in mixture. Add 46.55 lbs. (5 gallons) ethylene glycol and stir until the mixture is uniform. Finally, add sufficient water (8-10 gallons) to adjust viscosity for the method of application to dies. The resulting composition is a non-polluting or minimal air polluting, water-based forging die lubricant for use on steel, stainless steel, nickel-base, and titanium-base alloys. It does not flame, has minimal smoke, and contains low sulfur (a requirement for many nickel-base alloys). It is particularly adapted for hammer (impact) forging, while substitution of 2-5 wt.% mica (referred to as Example 2) for the sodium bicarbonate and ethylene glycol results in a formula particularly adapted for press (pressure) forging.
The sodium carboxymethyl cellulose (CMC) is the preferred member of a class of suspension aids known as "organic thickeners". The organic thickener tends to hold the other components in an homogeneous mixture. The class includes alkyl celluloses, polymethylvinyl ether-maleic anhydride, alkali metal alkylcelluloses and various proprietary compositions available under the trade names "KLUCEL" (hydroxypropylcellulose) and "METHOCEL".
The graphite is preferably added to the mixture as a 20-40 wt.% suspension of graphite in water. Such suspensions are sold commercially as "LQ-405 Aquaforge" by Quaker Chemical Co. of Conshohocken, Pa. or "147" by the Acheson Colloids Company, Port Huron, Mich. The graphite acts as a solid film lubricant between the workpiece and the die.
The sodium molybdate acts as an effective liquid film lubricant between the die and metal at 1600°-2200° F. It also acts as a rust inhibitor.
The sodium pentaborate (Sodium 1:5-borate) (Na 2 O . 5 B 2 O 3 .10 H 2 O) appears to act as an adhesive to wet the hot metal surface and adhere the entire composition to the workpiece and die surfaces. It also acts as a viscous film lubricant at high temperature. The pentaborate is formed by reacting one mole of borax (Sodium 1:2-borate) (Na 2 O . 2 B 2 O 3 . 10 H 2 O) with six moles of boric acid (H 3 BO 3 ) or three moles of anhydrous boric acid (B 2 O 3 ). This reaction can be effected in or out of the complete mixture.
Sodium bicarbonate acts as a die release to prevent the workpiece from "sticking" in the die. The bicarbonate releases CO 2 at forging conditions, forming a gas layer that assists in separating the workpiece from the die. In addition, it acts to prevent scale, to wet, and lubricate the surfaces.
Ethylene glycol acts with the other components to improve die release and prevent scale. It also helps to prevent freezing of the water-based mixture during storage and shipping.
The effective range of composition of the various components is:
______________________________________ Wt. %______________________________________Organic thickener 0.5-1.5Graphite (dry) 8-16Sodium molybdate 4-8Sodium pentaborate 2-5Sodium bicarbonate 1-5Ethylene glycol 1.0-20Water remainder______________________________________
Testing of the lubricant of Example 1 yielded the following results.
1. Good lubricity. The coefficient of friction was measured using the "Ring Compression Test" (Male and Cockcroft J. Inst. of metals 1964-65, 92, 38) but the results were not completely conclusive. Nevertheless, observations by experienced personnel on full scale forging processes indicated excellent lubricity over a wide range of workpiece materials and forging parameter as compared to commercially available lubricants. In addition, flow stress measurements were made by upsetting 4340 steel billets. The values obtained were as low or lower than many commercially available forging lubricants tested.
2. Low sulfur. The sulfur content is much lower than conventional oil base lubricants, being in the order of 800-1300 ppm compared to 10,000-30,000 ppm in oil based lubricants.
3. Minimal air pollution. Comparative tests were run under standard conditions which collected particulate material on a millipore filter from spraying weighed samples of different lubricants with the following results:
______________________________________ MilligramsLubricant particulate material______________________________________None 0.1Present Invention 1.4Commercial Water-based Lub. A 6.5Commercial Water-based Lub. B 19.4Standard Oil-based Lub. 124.9______________________________________
4. Nonsettling. Tests after the lubricant had been standing in a 55-gallon drum for several weeks indicated no heavy sludge was present on the bottom of the drum.
5. Flameless. There is insignificant flaming when the lubricant is sprayed on a die at 800° F.
6. Easy application and removal from dies. The lubricant can be sprayed or swabbed on hot dies (300°-900° F.) and adheres well when applied by an air-type or airless spray gun. It will not rust or corrode steel dies and may be readily removed by washing with a spray of water.
7. Good scale removal and die release characteristics. The ethylene glycol addition results in scale removal characteristics equivalent to that of oil when used on a forging. The ethylene glycol in combination with the sodium bicarbonate also provides a gas cushion at the die surface which aids in part removal from the hammer dies.
8. Effective lubrication of parts with widely different sizes and shapes. This lubricant has been used effectively on production parts with flat simple shapes and parts with ribs, bosses, shafts, etc. of complex shape. These parts have varied in weight from 20 pounds to 5,000 pounds.
While it will be apparent that the illustrated embodiments of the invention herein disclosed are well calculated adequately to fulfill the objects and advantages primarily stated, it is to be understood that the invention is susceptible to variation, modification, and change within the spirit and scope of the subjoined claims. | A lubricant composition comprising water, graphite, an organic thickener, sodium molybdate, and sodium pentaborate. Other additives are sodium bicarbonate, ethylene glycol, or mica. The composition is effective in the hot forging of metals, is virtually non-flammable, and generates very little atmospheric pollution during use. | 2 |
This application is a division of U.S. patent application Ser. No. 08/232,117, filed May 2, 1994, which is a continuation-in-part of U.S. patent application Ser. No. 07/785,851, filed Oct. 31, 1991, both now abandoned.
TECHNICAL FIELD
The present invention relates to the preparation of starting materials for use in the synthesis of quinolone antibacterial agents. More particularly, the invention relates to a process for preparing certain halo-substituted benzoic acids and acetophenones which may be employed in quinolone syntheses, as well as novel compounds useful in such a process.
BACKGROUND OF THE INVENTION
Substituted 1,4-dihydro-4-oxoquinoline-3-carboxylic acid derivatives (hereinafter quinolones) are known to be effective antibacterial agents (see, for example, U.S. Pat. No. 4,730,000, issued Mar. 8, 1988 to Chu). Halo-substituted benzoic acids and their corresponding esters and acetophenones are useful as starting materials in the synthesis of such quinolones, as disclosed in the published European patent application of Kumai et al., No. 0 303 291, published Feb. 15, 1989.
In particular, 2-chloro-4,5-difluorobenzoic acid (CDFBA), 2,4,5-trifluorobenzoic acid (TFBA), and their respective analogous acetophenones are advantageous starting materials for quinolone synthesis. Known methods of preparing these compounds, however, suffer from a number of drawbacks, including complex chemistry requiring specialized equipment; expensive or hard-to-obtain starting materials; materials hazards such as those associated with the use and decomposition of diazonium salts; and reactions having commercially undesirable selectivities and/or yields. There is therefore a continuing need for an improved process for preparing the above intermediates which overcomes some or all of these disadvantages.
SUMMARY OF THE INVENTION
Accordingly, a new process is disclosed for the preparation of CDFBA and TFBA from inexpensive and readily available starting materials. In one aspect of the present invention is disclosed a method for preparing a compound having the formula ##STR3## wherein X is chloro or fluoro; one of Y and Z is chloro and the other of Y and Z is nitro; and R is a radical selected from the group consisting of --CCl 3 , --CH 2 NO 2 , --CH(NO 2 )R 1 , --CH(CO 2 R 1 ) 2 , --CH(C(O)R 2 ) 2 , --CH(CN)CO 2 R 1 , --CH(CO 2 R 1 )COR 2 and --COR 2 , where R 1 is alkyl or arylalkyl and R 2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R 1 and R 2 may be the same or different at each occurrence. The method comprises reacting a nitrobenzene having the formula ##STR4## with an appropriate carbanion to form said compound (III). Such a carbanion may be generated by reacting a base with a nucleophile such as one selected from the group consisting of nitroalkanes, enamines, malonates, beta-ketoesters, cyanoacetates, malononitriles and beta-diketones. Bases which are suitable for this reaction include, for example, those selected from the group consisting of amines, amidines, hydroxides, alkoxides, hydrides, carbonates and bicarbonates. A preferred embodiment of the method is one in which the base is 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or 1,1,3,3-tetramethylguanidine, forming a substituted nitrobenzene product (III) in which R is --CH 2 NO 2 or --CH(NO 2 )CH 3 , X is fluoro, Y is nitro, and Z is chloro.
In a second aspect of the present invention, a method is disclosed for preparing a compound having the formula ##STR5## wherein X is chloro or fluoro; one of Y and Z is chloro; and the other of Y and Z is nitro. This method comprises reacting a substituted nitrobenzene, such as one having the formula ##STR6## wherein R is selected from the group consisting of --CCl 3 , --CH 2 NO 2 , --CH(NO 2 )R 1 , --CH(CO 2 R 1 ) 2 , --CH(C(O)R 2 ) 2 , --CH(CN)CO 2 R 1 , --CH(CO 2 R 1 )COR 2 and --COR 2 , where R 1 and R 2 are as previously defined, with an appropriate acid. In a preferred embodiment, R is --CH(CO 2 R 1 ) 2 or --CH(NO 2 )R 1 and the acid is sulfuric or nitric, with about 50% sulfuric or about 40% nitric acid being most preferred. The product (IV) of this oxidation reaction may then be recrystallized, as for example from ethyl acetate or methylene chloride.
In a further aspect of the present invention, a method is disclosed for preparing a compound having the formula ##STR7## wherein X is chloro or fluoro and R' is hydroxy or fluoro. The method comprises reacting a benzoyl chloride having the formula ##STR8## wherein X' is chloro or fluoro, one of Y and Z is chloro, and the other of Y and Z is nitro, with an appropriate fluoride, and preferably with lithium, sodium, potassium, cesium or alkylammonium fluoride. This reaction is subject to the proviso that when X in formula (VI) is chloro, Z in formula (V) must also be chloro.
In a preferred embodiment of the above method, Y is nitro; Z is chloro; the fluoride used is potassium fluoride; and the fluorination reaction is carried out in N,N-dimethylformamide (DMF) at atmospheric refluxing temperature. In all cases, however, a product of fluorination may be hydrolyzed to obtain a compound of formula (VI) where R' is hydroxy. Alternatively, the fluorination product may be distilled to obtain a compound of formula (VI) where R' is fluoro.
Also comprised by the present invention are novel synthetic intermediates which may be prepared according to the above inventive methods. Included are compounds having the formula ##STR9## wherein, as before, X is chloro or fluoro; one of Y and Z is chloro and the other is nitro; and R is selected from the group consisting of --CCl 3 , --CH 2 NO 2 , --CH(NO 2 )R 1 , --CH(CO 2 R 1 ) 2 , --CH(C(O)R 2 ) 2 , --CH(CN)CO 2 R 1 , --CH(CO 2 R 1 )COR 2 and --COR 2 , where R 1 and R 2 are as previously defined. Other compounds of the invention are those which have the formula ##STR10## wherein X again is chloro or fluoro, and R' is hydroxy or chloro.
DETAILED DESCRIPTION OF THE INVENTION
The methods and compounds of the present invention are herein described using certain terms which, except where otherwise indicated, are accorded the following definitions:
The term "alkoxide" refers to a compound of the formula R 3 OM or (R 3 O) 2 M, where R 3 is alkyl as defined below and M is a suitable cation such as lithium, sodium, potassium or magnesium.
The term "alkyl" refers to a straight- or branched-chain, saturated hydrocarbon radical of one to ten carbon atoms including, but not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl and the like.
The term "amidine" refers to a compound of the formula R 4 C(NR 5 R 6 )═NR 7 where R 5 , R 6 and R 7 are independently alkyl and R 4 is selected from amino and alkyl, or where either or both of R 5 and R 6 taken together with either or both of R 4 and R 7 form a group having the formula --(CH 2 ) m -- where m is two to six including, but not limited to, DBU, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), guanidines such as 1,1,3,3-tetramethyl-guanidine or 2-t-butyl-1,1,3,3-tetramethylguanidine and the like.
The term "amine" refers to a tertiary amine of the formula N(R 8 ) 3 or a tertiary diamine of the formula N(R 9 ) 3 N, where R 8 is alkyl of from two to ten carbons or arylalkyl having an alkyl component of from two to ten carbons and R 9 is a group of the formula --(CH 2 ) n -- where n is two to four, including, but not limited to, triethylamine, triethylenediamine and the like.
The term "aryl" refers to a cyclic or fused bicyclic, aromatic hydrocarbon radical such as phenyl or naphthyl.
The term "arylalkyl" refers to an aryl radical linked to the parent molecule via an alkyl group including, but not limited to, benzyl, phenylethyl, phenylbutyl, naphthylmethyl, naphthylpentyl and the like.
The term "beta-diketone" refers to a compound of the formula R 11 C(O)CH(R 10 )C(O)R 12 , where R 10 is selected from hydrogen, alkyl, aryl and arylalkyl and R 11 and R 12 are independently alkyl, aryl or arylalkyl.
The term "beta-ketoester" refers to a compound of the formula R 11 C(O)CH(R 13 )CO 2 R 8 , where R 13 is selected from hydrogen, alkyl and arylalkyl, R 11 is alkyl, aryl or arylalkyl, and R 8 is alkyl or arylalkyl.
The term "bicarbonate" refers to a compound of the formula M 1 HCO 3 , where M 1 is a suitable cation such as lithium, sodium or potassium.
The term "carbonate" refers to a compound of the formula (M 1 ) 2 CO 3 where M 1 is a suitable monovalent cation such as lithium, sodium or potassium, or of the formula M 2 CO 3 where M 2 is a divalent cation such as magnesium or calcium.
The term "cyanoacetate" refers to a compound of the formula CH(CN)(R 14 )CO 2 R 15 , where R 14 and R 15 are independently selected from hydrogen, alkyl and arylalkyl.
The term "enamine" refers to a compound of the formula C(NR 16 R 17 )(R 14 )═CHR 15 , where R 16 and R 17 are independently alkyl of one to ten carbons and R 14 and R 15 are independently selected from hydrogen, alkyl and arylalkyl.
The term "fluoride" refers to a compound of the formula M 3 F, where M 3 is a suitable cation such as lithium, sodium, potassium, cesium or alkylammonium.
The term "hydride" refers to a compound of the formula M 1 H, where M 1 is a suitable cation such as lithium, sodium or potassium.
The term "hydroxide" refers to a compound of the formula M 4 OH, where M 4 is a suitable cation such as lithium, sodium, potassium, magnesium or alkylammonium.
The term "malonate" refers to a compound of the formula CH(R 13 )(CO 2 R 18 ) 2 , where R 13 and R 18 are selected from hydrogen, alkyl and arylalkyl.
The term "malononitrile" refers to a compound of the formula CH(R 10 )(CN) 2 , where R 10 is selected from hydrogen, alkyl, aryl and arylalkyl.
The term "nitroalkane" refers to a compound having the formula CH(R 19 )(R 20 )NO 2 , where R 19 and R 20 are independently selected from hydrogen, alkyl and aryl. ##STR11##
The present invention will be better understood in connection with the preceding reaction scheme. In Scheme I, 2,4,5-trichloronitrobenzene (I) is converted to 5-chloro-2,4-difluoronitrobenzene (IIa) in a fluorination reaction (reaction step 1) using a fluorinating reagent such as potassium fluoride. Upon exposure to an anion of a nucleophile such as nitromethane or malonate, compound (IIa) undergoes a nucleophilic substitution reaction (step 2) to produce isomeric nitrobenzene derivatives (IIIa) and (IIIb), which are then oxidized (in step 3) to the corresponding benzoic acids (IVa) and (IVb) using, for example, nitric acid. Subsequent fluorodenitration, fluorodechlorination and hydrolysis (in step 4) of the mixture of benzoic acids (IVa) and (IVb) results in the formation of the quinolone synthesis starting material TFBA (IXa, where X is fluoro), while fluorodenitration alone and hydrolysis of the isolated benzoic acid (IVa) yields the starting material CDFBA (IXb, where X is chloro). Isolation of a particular isomer from a product mixture may be accomplished by known separatory techniques, such as crystallization or column chromatography.
Alternatively, 2,4,5-trichloronitrobenzene (I) may without prior fluorination undergo nucleophilic substitution (in reaction step 5) to form isomeric dichloronitrobenzene derivatives (VIIa) and (VIIb), followed by oxidization (in step 6) to the corresponding benzoic acids (VIIIa) and (VIIIb). The mixture of benzoic acids (VIIIa) and (VIIIb) is then fluorodenitrated, fluorodechlorinated and hydrolyzed (in step 7) to form TFBA (IXa).
Not shown but obtainable via Scheme I are the quinolone starting materials 2-chloro-5-fluoro-4-nitroacetophenone and 4-chloro-5-fluoro-2-nitroacetophenone, which can be prepared from nitrobenzene derivatives (IIIa) and (IIIb) via a Nef reaction. Also omitted from the scheme, but included among the compounds of the present invention, are benzoyl halide intermediates (V) and (VI) which are produced during reaction steps 4 and 7 and discussed in greater detail below.
The above procedures may be carried out using a variety of reagents and reaction conditions. In the substitution reactions of steps 2 and 5, which are analogous and are demonstrated in Examples 2, 7-10 and 14-18 below, a variety of solvents are suitable including common protic or aprotic polar solvents such as DMF, dimethyl sulfoxide (DMSO), dioxane, pyridine, THF, N,N-dimethylacetamide (DMAC), and two- to five-carbon alcohols, as well as mixtures thereof such as DMSO/water. Alternatively, the nucleophilic substitutions of these steps may be performed neat in the presence of a phase-transfer catalyst, as for example tris(3,6-dioxaheptyl)amine (TDA), tricaprylylmethylammonium chloride, tetrabutylammonium fluoride (TBAF) or tetrabutylammonium chloride (TBAC).
The oxidation reactions of steps 3 and 6 may be carried out as single- or two-step reactions, as demonstrated in Examples 3, 5, 11 and 12, and are likewise capable of considerable variation. When performed stepwise, the oxidation may be performed neat or in a solvent such as water, acetic acid or a water-miscible organic solvent, as for example dioxane. Reagents such as acetic acid/HCl, DMSO/NaCl or H 2 SO 4 may be used, optionally followed by, for example, nitric acid, permanganate or potassium peroxymonosulfate, with the reaction proceeding at from about 25° C. to about 110° C. Alternatively, when run as a one-step reaction the reaction may be carried out neat or in water, using nitric acid alone or permanganate in acid at from about 25° C. to about 110° C.
The fluorodenitration and/or fluorodechlorination reactions of steps 4 and 7 are demonstrated in Examples 4, 6 and 13. These may be performed over a temperature range of about 80° C. to about 250° C., depending on the presence or absence of a phase-transfer catalyst such as tetraphenylphosphonium bromide (TPPB), TBAF or TBAC. Polar or non-polar, aprotic solvents such as DMF, 1-methyl-2-pyrrolidinone (NMP), DMAC, 1,3-dimethyl-2-imidazolidinone (DMI), tetramethylene sulfone (TMSO 2 ), toluene and xylenes are preferred, and may be used either alone or in combination. The fluorinations of steps 4 and 7 are preceded by the formation, using thionyl chloride, of benzoyl chloride intermediates (V); if desired, these compounds may be isolated without further reaction.
Reagents and conditions may be chosen in each of the above reactions to select for a particular isomer or product. In a preferred embodiment of the oxidation reaction, for example, a product is obtained in which the major component, 4-nitrobenzoic acid, is present in a 23:1 ratio to the 2-nitrobenzoic acid isomer, using a mixture of alpha-aryl nitroalkanes (IlIa and IIIb, where R is --CH(NO 2 )R 1 ) in which the ratio of the corresponding isomers is only 2:1 (Example 5) as a starting material. Likewise, the fluorination of benzoyl chloride intermediates (V) may be carried out under conditions which favor (i) fluorinating at all positions to form a trifluorobenzoyl fluoride intermediate (Example 4); (ii) forming a chlorodifluorobenzoyl fluoride intermediate without replacement of the ring chlorine (Example 6); or (iii) selectively converting a mixture of benzoic acids (IVa and IVb, in a ratio of about 2.5:1) to a single isomer, 2-chloro-4,5-difluorobenzoyl fluoride, again without replacing the ring chlorine (Example 13).
The foregoing methods and compounds of the present invention may be better understood by reference to the following Examples, which are provided for illustration and are not intended as a limitation upon the present invention.
EXAMPLE 1
5-Chloro-2,4-difluoronitrobenzene (2)
200 g (0.883 mol) of 2,4,5-trichloronitrobenzene and 128.4 g (2.21 mol) of KF in 500 ml of tetramethylenesulfone were reacted at 200° C. under nitrogen for 3.5 hours. To the mixture was added 500 ml of ethyl acetate and the precipitate was filtered. The filtrate was washed with brine, dried over magnesium sulfate and concentrated. Distillation at 85°-90° C./0.9 mm afforded pure compound 2 with more than 70% yield.
1 H-NMR from CDCl 3 (δ ppm): 7.17 (dd, 1H, J=8Hz, 9Hz), 8.26 (dd, 1H, J=7.5Hz, 7.5Hz). MS(m/z): 193 (M + ).
EXAMPLE 2
5-Chloro-2-fluoro-4-(nitromethyl)nitrobenzene (3) and 5-Chloro-4-fluoro-2-(nitromethyl)nitrobenzene (4)
DBU (16.5 g, 0.11 mol) in 20 ml of ethyl acetate was cooled in an ice-bath and treated with nitromethane (3.1 ml, 0.057 mol). The solution was stirred under nitrogen for 10 min and 10.0 g of compound 2 (0.052 mol, from example 1) in 20 ml of ethyl acetate was added dropwise at the same temperature. The dark red mixture was stirred for 2 hours and then warmed up to room temperature. The mixture was treated with 10% HCl (10 ml) and extracted with ethyl acetate. The ethyl acetate layer was washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the product (10.9 g, 89.9%). The product consisted of compounds 3 and 4 in a ratio of 2:1 based on NMR analysis. The two isomers were separated by column chromatography (silica gel, 10% ethyl acetate/hexanes).
Compound 3: yellowish crystals, mp 70°-72° C. 1 H-NMR from CDCl 3 (δ ppm): 5.64 (s, 2H), 7.47 (d, 1H, J=10.5Hz), 8.22 (d, 1H, J=7Hz).
Compound 4: 1 H-NMR from CDCl 3 (δ ppm): 5.81 (s, 2H), 7.31 (d, 1H, J=9Hz), 8.44 (d, 1H, J=6Hz). MS (m/z): 234 (M + ).
EXAMPLE 3
2-Chloro-5-fluoro-4-nitrobenzoic Acid (5) and 4-Chloro-5-fluoro-2-nitrobenzoic Acid (6)
The product from Example 2 (12.1 g, 0.052 mol) in of 25 ml of conc. nitric acid and 20 ml of water was heated at 90° C. for 2 hours. The solution was cooled to room temperature and diluted with 20 ml of water. The mixture was extacted with ethyl acetate. The ethyl acetate solution was washed with brine and extracted with saturated aqueous sodium bicarbonate. The water layer was separated, acidified with conc. HCl, and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated. The residue was recrystallized from ethyl acetate to afford 7.5 g (66%) of the product which consisted of compounds 5 and 6 in a ratio of 2:1 based on NMR analysis. The two isomers were separated by crystallization from ethyl acetate-methylene chloride.
Compound 5: mp 129°-131° C. (EtOAc-CH 2 Cl 2 ). 1 H-NMR from DMSO-d 6 (δ ppm): 8.01 (d, 1H, J=11Hz), 8.36 (d, 1H, J=7Hz), 14.2 (br, 1H).
Compound 6: 1 H-NMR from DMSO-d 6 (δ ppm): 7.96 (d, 1H, J=9 Hz), 8.45 (d, 1H, J=6 Hz), 14.2 (br, 1H). MS (m/z): 219 (M + ).
EXAMPLE 4
2,4,5-Trifluorobenzoic Acid (7)
A mixture of compounds 5 and 6 from Example 3 (10.95 g, 0.05 mol) was treated with thionyl chloride (5.47 ml, 0.075 mol) and the mixture was refluxed under nitrogen for 4 hours. The excess of thionyl chloride was removed by distillation and the remainder distilled at 85°-90° C./0.7 mm to afford 10.6 g (89.5%) of the corresponding benzoyl chlorides.
The benzoyl chlorides (10 g, 42 mmol) were dissolved in 30 ml of tetramethylenesulfone. To this was added 15 g (26 mmol) of spray-dried KF and 17.5 g of phthalloyl dichloride. The mixture was heated at 165° C. for 3 hours under nitrogen. The product 2,4,5-trifluorobenzoyl fluoride was distilled at 65°-70° C./25 mm. Water was added to the distillate and the benzoic acid 7 was collected by filtration as white crystals (65% yield).
1 H-NMR from CDCl 3 -CD 3 OD (δ ppm): 7.04 (m, 1H), 7.82 (m, 1 H). MS (m/z): 176 (M + ).
EXAMPLE 5
Selective Formation of 2-Chloro-5-fluoro-4-nitrobenzoic Acid (5)
The product prepared in Example 2 (2 g, 2.0 mmol) in 3 ml of conc. sulfuric acid and 2 ml of water was heated at 100° C. for 40 min. The mixture was cooled, diluted with 4 ml of water, and extacted with ethyl acetate. The ethyl acetate layer was partitioned with saturated sodium bicarbonate (5 ml×3). The aqueous layer was acidified and extracted with ethyl acetate. The combined ethyl acetate fractions were dried over magnesium sulfate, and concentrated. The residue was recrystallized from ethyl acetate to form a crystalline product (0.31 g, 50%) consisting of compounds 5 and 6 in a ratio of 23:1 based on NMR data.
EXAMPLE 6
2-Chloro-4,5-difluorobenzoic Acid (8)
The product of Example 5 (20 g, 91 mmol) was suspended in 60 ml of thionyl chloride and heated to reflux for 3 hours under nitrogen. The excess of thionyl chloride was distilled off and the resultant acid chloride was dissolved in 40 ml of tetramethylenesulfone. To the solution was added 16 g (276 mmol) of spray-dried KF and 38.5 g of 4-chlorosulfonyl chloride. (This Example was also duplicated with 40 g benzenesulfonyl chloride in place of the 4-chlorosulfonyl chloride, with substantially identical results.) The mixture was then heated at 125° C. for 3 hours under nitrogen. Distillation of the reaction mixture at 70°-75° C./15 mm afforded pure 2-chloro-4,5-difluorobenzoyl fluoride. The liquid product was hydrolyzed with water and dried under vacuum to give 75% yield of compound 8 as white crystals.
1 H-NMR from DMSO-d 6 (δ ppm): 7.82 (dd, 1 H, J=11 Hz, 7 Hz), 7.91 (dd, 1 H, J=11Hz, 9 Hz). MS (m/z): 192 (M + ).
EXAMPLE 7
Dimethyl 2-(2-Chloro-5-fluoro-4-nitrophenyl)malonate (9) and Dimethyl 2-(4-Chloro-5-fluoro-2-nitrophenyl)malonate (10)
Diethyl 2-(2-Chloro-5-fluoro-4-nitrophenyl)malonate (9a) and Diethyl 2-(4-Chloro-5-fluoro-2-nitrophenyl)malonate (10a)
Variation 1: The preparations of compounds 9 and 9a and their respective isomers 10 and 10a were carried out in the same manner as in Example 2 using dimethyl and diethyl malonate, respectively, in place of nitromethane. The products were isolated in quantitative yield. In each reaction, a 1.2:1 ratio mixture of the 2-chloro-5-fluoro-4-nitrophenyl and 4-chloro-5-fluoro-2-nitrophenyl malonates was formed, based on NMR analysis. The isomeric products were separated by column chromatography (silica gel, 10% EtOAc/hexanes).
Variation 2: To suspensions of lithium hydroxide monohydrate (47.9 g, 1.14 mol) in DMSO (100 ml) at 15° C. were added the appropriate dialkyl malonate (86.4 ml, 0.57 mol). The mixtures were stirred for 15 min under nitrogen, and a solution of compound 2 (from Example 1, 100 g, 0.52 mol) in 50 ml of DMSO added dropwise. The dark red mixtures were stirred under nitrogen at room temperature for 3 hours, quenched with 10% HCl, and extracted with ethyl acetate. The ethyl acetate layers were washed with brine and dried over magnesium sulfate. The solvent was removed under reduced pressure to give the pure products (quantitative yield), consisting in each case of the 2-chloro-5-fluoro-4-nitrophenyl and 4-chloro-5-fluoro-2-nitrophenyl malonates in a ratio of 1.2:1 based on NMR analysis.
Compound 9: mp 51°-51° C. 1 H-NMR from CDCl 3 (δ ppm): 3.82 (s, 6H), 5.26 (s, 1H), 7.59 (d, 1H, J=10Hz), 8.15 (d, 1H, J=7Hz).
Compound 10: 1 H-NMR from CDCl 3 (δ ppm): 3.82 (s, 6 H), 5.37 (s, 1H), 7.48 (d, 1H, J=10Hz), 8.22 (d, 1H, J=7Hz). MS (m/z): 323 ([M+NH 4 ] + ).
Compound 9a: 1 H-NMR from CDCl 3 (δ ppm): 1.30 (t, 6H, J=7Hz), 4.29 (q, 4H), 5.22 (s, 1H), 7.60 (d, 1H, J=11Hz), 8.15 (d, 1H, J=7Hz).
Compound 10a: 1 H-NMR from CDCl 3 (δ ppm): 1.31 (t, 6H, J=7Hz), 4.29 (q, 4H), 5.32 (s, 1H), 7.40 (d, 1H, J=9Hz), 8.22 (d, 1H, J=7Hz). MS (m/z): 351 ([M+NH 4 ] + ).
EXAMPLE 8
Methyl 2-(2-Chloro-5-fluoro-4-nitrophenyl)cyanoacetate (11) and Methyl 2-(4-Chloro-5-fluoro-2-nitrophenyl)cyanoacetate (12)
The preparation of compounds 11 and 12 was carried out in a manner analogous to that of Example 2 using 1 g (5.2 mmol) of compound 2 (from Example 1) and methyl cyanoacetate. The product consisted of 11 and 12 in a ratio of 1:2 with a total yield of 100%. The two isomers were separated by column chromatography (silica gel, 10% EtOAc/hexanes).
Compound 11: 1 H-NMR from CDCl 3 (δ ppm): 3.90 (s, 3H), 5.21 (s, 1H), 7.62 (d, 1H, J=11 Hz), 8.20 (d, 1H, J=7 Hz).
Compound 12: off-white solid, mp 92.5°-94° C. 1 H-NMR from CDCl 3 (δ ppm): 3.90 (s, 3H), 5.70 (s, 1H), 7.61 (d, 1H, J=9 Hz), 8.39 (d, 1H, J=7 Hz). MS (m/z): 290 ([M+NH 4 ] + ).
EXAMPLE 9
Ethyl 2-(2-Chloro-5-fluoro-4-nitrophenyl)acetoacetate (13) and Ethyl 2-(4-Chloro-5-fluoro-2-nitrophenyl)acetoacetate (14)
The preparation of compounds 13 and 14 was conducted in the same manner as in Example 7 with 0.5 g of compound 2 (from Example 1) and ethyl acetoacetate. The product consisted of compounds 13 and 14 in a ratio of 1:1 with a total yield of 0.7 g (89%). The two isomeric products were separated by column chromatography (silica gel, 10% EtOAc/hexanes).
Compound 13: 1 H-NMR from CDCl 3 (δ ppm): 1.20 (t, 3H, J=7.5 Hz, 7.5 Hz), 1.84 (s, 3 H), 4.24 (q, 2H), 7.29 (d, 1H, J=11 Hz), 8.16 (d, 1H, J=7 Hz), 13.15 (s, 1H),
Compound 14: 1 H-NMR from CDCl 3 (δ ppm): 1.12 (t, 3H, J=7 Hz), 1.90 (s, 3H), 4.16 (q, 2H), 7.09 (d, 1H, J=8Hz), 8.16 (d, 1H, J=7 Hz), 13.04 (s, 1H). MS (m/z): 321 ([M+NH 4 ] + ).
EXAMPLE 10
5-Chloro-2-fluoro-4-(trichloromethyl)nitrobenzene (15) and 5-Chloro-4-fluoro-2-(trichloromethyl)nitrobenzene (16)
The preparation of compounds 15 and 16 was carried out as in Example 2 using chloroform and compound 2. The product consisted of compounds 15 and 16 in a ratio of 1:1 with a total yield of 44%.
Compound 15: 1 H-NMR from CDCl 3 (δ ppm): 6.91 (d, 1H, J=12Hz), 8.12 (d, 1H, J=7Hz).
Compound 16: 1 H-NMR from CDCl 3 (δ ppm): 6.32 (d, 1H, J=13Hz), 8.29 (d, 1H, J=7Hz).
EXAMPLE 11
2-Chloro-5-fluoro-4-nitrobenzoic Acid (5) and 4-Chloro-5-fluoro-2-nitrobenzoic acid (6) From Oxidation of Dialkyl (Chloro-fluoro-nitrophenyl)malonates
Variation 1: Each of the mixtures of dialkyl malonate compounds 9/10 and 9a/10a prepared in Example 7 (2 g, 6.56 mmol) and 13 ml of 40% HNO 3 were heated at 70° C. for 3 hours and then at 90° C. for 13.5 hours. The reaction mixtures were cooled to room temperature and the precipitates filtered. The solid products collected were washed with water, dissolved in ethyl acetate, and extracted with saturated aqueous sodium bicarbonate. The aqueous layers were acidified to pH 2 with conc. HCl and extracted with ethyl acetate. The organic layers were dried over magnesium sulfate and concentrated to give light-yellow crystalline product (0.72 g, 50%). The 1 H-NMR spectra of the products showed them to be mixtures of compounds 5 and 6 in a 2.6:1 ratio.
Variation 2: A mixture of the dimethyl malonates 9 and 10 from Example 7 (20 g, 0.06 mol) and 60 ml of 25% of sulfuric acid was heated at refluxing temperature for 21 hours. The solution was cooled in an ice bath and the precipitate collected by filtration. The solid material was treated with 60 ml of 40% of nitric acid and the mixture refluxed for 30 hours. The precipitate formed upon cooling of the solution was filtered, washed with water, and dried in vacuum. More product was obtained by extracting the mother liquor with ethyl acetate. The product (total yield 8.81 g, 67%) consisted of compounds 5 and 6 in a ratio of about 4:1, based on NMR spectrum analysis. Crystallization of the product from variation 1 or variation 2 from ethylacetate gave pure compound 5.
EXAMPLE 12
2-Chloro-5-fluoro-4-nitrobenzoic Acid (5) and 4-Chloro-5-fluoro-2-nitrobenzoic acid (6) From Oxidation of Ethyl (Chloro-fluoro-nitrophenyl)acetoacetates
The oxidation of the acetoacetates 13 and 14 from Example 9 was conducted in the same manner as is described in Example 11. The product obtained (0.72 g, 50%) consisted of compounds 5 and 6 in a 1:1 ratio based on NMR analysis.
EXAMPLE 13
2-Chloro-4,5-difluorobenzoic Acid (8) via Selective Fluorination
The combined benzoic acids made in each of Examples 3, 11 and 12 (consisting of compounds 5 and 6 in a ratio of about 2:1) were converted to the corresponding acid chlorides as in Example 4. The acid chlorides (2 g, 8.4 mmol) were dissolved in 4 ml of tetramethylenesulfone and treated with spray-dried KF (2.0 g, 34.5 mmol). The mixture was heated at 150° C. under nitrogen for 3 hours and the product distilled at 70°-75° C./15 mm. The acid fluoride collected was hydrolyzed with water and the product was dried in vacuum to give pure compound 8 as the only product (0.4 g, 24%).
EXAMPLE 14
2,5-Dichloro-4-(1-nitroethyl)nitrobenzene (17) and 4,5-Dichloro-2-(1-nitroethyl)nitrobenzene (18)
To a solution of 75.5 g of DBU (0.486 mol) in 350 ml of ethyl acetate cooled in an ice bath were sequentially added dropwise 18.2 g (0.243 mol) of nitroethane and 50 g (0.221 mol) of 2,4,5-trichloronitrobenzene (compound 1) in 100 ml of ethyl acetate. The resultant mixture was stirred under nitrogen at room temperature for 2 days. The mixture was acidified with 10% HCl and extracted with ethyl acetate. The ethyl acetate solution was washed with brine, dried over magnesium sulfate, and concentrated. The product obtained consisted of compounds 17 and 18 in a ratio of 1:3 based on NMR analysis (50.3 g, 86%). The two isomers were separated by chromatography (silica gel, 10% EtOAc/hexanes).
2,5-Dichloro-4-(1-nitroethyl)nitrobenzene (17): 1 H-NMR from CDCl 3 (δ ppm): 1.97 (d, 3H, J=7Hz), 6.06 (q, 1H), 7.67 (s, 1H), 8.01 (s, 1H).
4,5-Dichloro-2-(1-nitroethyl)nitrobenzene (18): mp 48°-49° C. 1 H-NMR from CDCl 3 (δ ppm): 2.01 (d, 3H, J=7Hz), 6.25 (q, 1H), 7.71 (s, 1H), 8.23 (s, 1H). MS(m/z): 282 ([M+NH 4 ] + ).
EXAMPLE 15
Dimethyl 2-(4,5-Dichloro-2-nitrophenyl)malonate (19) and Dimethyl 2-(2,5-Dichloro-4-nitrophenyl)malonate (20)
The preparation of compounds 19 and 20 was carried out as in Example 2 using dimethyl malonate in place of nitromethane. The yellowish crystalline product consisted of compounds 19 and 20 in a ratio of 2.5:1 with a total yield of 100%.
Compound 19: 1 H-NMR from CDCl 3 (δ ppm): 3.76 (s, 6H), 5.24 (s, 1H), 7.78 (s, 1H), 7.97 (s, 1H).
Compound 20: 1 H-NMR from CDCl 3 (δ ppm): 3.83 (s, 6H), 5.31 (s, 1H), 7.65 (s, 1H), 8.21 (s, 12H). MS (m/z): 339 ([M+NH 4 ] + ).
EXAMPLE 16
Methyl 2-(2,5-Dichloro-4-nitrophenyl)cyanoacetate (21) and Methyl 2-(4,5-Dichloro-2-nitrophenyl)cyanoacetate (22)
The preparation of compounds 21 and 22 was carried out as in Example 2 using methyl cyanoacetate in place of nitromethane. The product consisted of compounds 21 and 22 in a ratio of 1:3 with a total yield of 93%. The two isomers were separated by column chromatography (silica gel, 8% EtOAc/hexanes).
Compound 21: 1 H-NMR from CDCl 3 (δ ppm): 3.90 (s, 3H), 5.20 (s, 1H), 7.82 (s, 1H), 8.01 (s, 1H).
Compound 22: white solid, mp 98.7°-99.8° C. 1 H-NMR from CDCl 3 (δ ppm): 3.90 (s, 3H), 5.68 (s, 1H), 7.89 (s, 1H), 8.48 (s, 1H). MS (m/z): 306 ([M+NH 4 ] + ).
EXAMPLE 17
Ethyl 2-(2,5-Dichloro-4-nitrophenyl)acetoacetate (23) and Ethyl 2-(4,5-Dichloro-2-nitrophenyl)acetoacetate (24)
The preparation of compounds 23 and 24 was carried out as in Example 7 using ethyl acetoacetate in place of nitromethane. The product consisted of compounds 23 and 24 in a ratio of 1:3 with a total yield of 90%. The two isomers were separated by column chromatography (silica gel, 8% ethyl acetate/hexanes).
Compound 23: 1 H-NMR from CDCl 3 (δ ppm): 1.20 (t, 3H, J=7.5Hz), 1.85 (s, 3H), 4.24 (m, 2H), 7.42 (s, 1H), 8.0 (s, 1H), 13.15 (s, 1H).
Compound 24: 1 H-NMR from CDCl 3 (δ ppm): 1.13 (t, 3H, J=7.5Hz), 1.91 (s, 3H), 4.22 (m, 2H), 7.40 (s, 1H), 8.14 (s, 1H), 13.05 (s, 1H). MS (m/z): 337 ([M+NH 4 ] + ).
EXAMPLE 18
4,5-Dichloro-2-nitrobenzoic Acid (25) and 2,5-Dichloro-4-nitrobenzoic Acid (26)
A mixture of 308 g (0.881 mol) of the malonates from Example 15, 150 ml of HOAc, 50 ml of water, and 150 ml of conc. HCl was heated at reflux for 2 days and then cooled to room temperature. The precipitate was collected by filtration, washed with water, treated with 200 ml of conc. HNO 3 and the mixture refluxed for 2 days. The solution was cooled to room temperature and the light yellow precipitate was filtered, washed with water, and dried in vacuum. The benzoic acids obtained consisted of compounds 25 and 26 in a ratio of 1.8:1 (total yield: 170 g, 82%).
Compound 25: 1 H-NMR from DMSO-d 6 (δ ppm): 8.02 (S, 1H), 8.17 (S, 1H).
Compound 26: 1 H-NMR from DMSO-d 6 (δ ppm): 8.09 (s, 1H), 8.15 (s, 1H).
EXAMPLE 19
2,4,5-Trifluorobenzoic Acid (7)
The benzoic acids from Example 18 were converted to the corresponding acid chlorides as in Example 4 with thionyl chloride. The acid chlorides were then reacted with KF in TMSO 2 as described in Example 4 to produce 2,4,5-trifluorobenzoic acid (after hydrolysis of the trifluorobenzoyl fluoride) in a 15% yield.
EXAMPLE 20
2-Chloro-5-fluoro-4-(1-nitroethyl)nitrobenzene (27) and 4-Chloro-5-fluoro-2-(1-nitroethyl)nitrobenzene (28)
A solution of 1.4 ml (10.2 mmol) of DBU in 2 ml of ethyl acetate was cooled to 0° C. and treated sequentially with 0.38 ml (5.3 mmol) of nitroethane and 1.0 g (5.2 mmol) of compound 2 in 3 ml of ethyl acetate. The dark-red solution was stirred for 1 hour (0° C.-20° C.) and then acidified with 10% HCl. The mixture was extracted with ethyl acetate, and the ethyl acetate solution dried over sodium sulfate and concentrated to give 1.1 g (84%) of pure compounds 27 and 28 in a ratio of 2:1. The two isomeric products were separated by column chromatography (silica gel, 10% EtOAc/hexanes).
Compound 27: 1 H-NMR from CDCl 3 (δ ppm): 1.96 (d, 3H, J=7Hz), 6.08 (q, 1H), 7.46 (d, 1H, J=11Hz), 8.20 (d, 1H, J=6.5Hz).
Compound 28: 1 H-NMR from CDCl 3 (δ ppm): 2.0 (d, 3H, J=7Hz), 6.28 (q, 1H), 7.42 (d, 1H, J=10Hz), 8.25 (d, 1H, J=6.5Hz). MS (m/z): 248 (M + ).
EXAMPLE 21
2-Chloro-5-fluoro-4-nitroacetophenone (29) and 4-Chloro-5-fluoro-2-nitroacetophenone (30)
The product from Example 18 (1.0 g, 4.0 mmol) was dissolved in 5 ml of methanol and cooled to 0° C. To the solution were sequentially added 10 ml of 30% H 2 O 2 and 4.0 g (29 mmol) of potassium carbonate in 10 ml of water. The mixture was stirred overnight at room temperature and partitioned with ethyl acetate. The ethyl acetate layer was washed with 5% HCl and then brine, and was dried with sodium sulfate. The solvent was evaporated to give 85.7% of the product which consisted of compounds 29 and 30 in a ratio of 2:1. The two isomers were separated by columnchromatography (silica gel, 8% ethyl acetate-hexanes).
Compound 29: mp 105.4°-106.7° C. 1 H-NMR from CDCl 3 (δ ppm): 2.69 (s, 3H), 7.46 (d, 1H, J=10 Hz), 8.15 (d, 1H, J=6Hz).
Compound 30: mp 117.7°-119.7° C. 1 H-NMR from CDCl 3 (δ ppm): 2.55 (s, 3H), 7.23 (d, 1H, J=11 Hz), 8.25 (d, 1H, J=7 Hz). MS (m/z): 235 ([M+NH 4 ] + ).
The above embodiments of the present invention are intended to be illustrative and not restrictive, the scope of the invention being instead defined by the appended claims and equivalencies embraced thereby. It is expected that the particulars of the foregoing description may be readily modified by those skilled in the art without departing from the spirit or essential characteristics thereof. | A process for the preparation of 2-chloro-4,5-difluorobenzoic acid and 2,4,5-trifluorobenzoic acid as well as synthetic intermediates useful in and prepared according thereto, comprising reacting a nitrobenzene having the formula ##STR1## wherein X is chloro or fluoro, with an appropriate carbanion to form a compound having the formula ##STR2## wherein one of Y and Z is chloro and the other is nitro, and R is a radical selected from the group consisting of --CCl 3 , --CH 2 NO 2 , --CH(NO 2 )R 1 , --CH(CO 2 R 1 ) 2 , --CH(C(O)R 2 ) 2 , --CH(CN)CO 2 R 1 , --CH(CO 2 R 1 )COR 2 and --COR 2 where R 1 is alkyl or arylalkyl and R 2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R 1 and R 2 may be the same or different at each occurrence. | 2 |
FIELD OF THE INVENTION
The present invention relates to a primary color video signal output circuit used in television receivers or other video display devices.
BACKGROUND OF THE INVENTION
Television and monitor displays may be subject to high luminance signals. As a result, when there is higher saturation of color, higher luminance, or larger amplitude in a video signal than desired, the linearity of reproduction of color signals may be sacrificed. This leads to an undesirable color saturation (color distortion) on the display screen. To solve this problem, a primary color video signal output circuit is disclosed, for example, in Japanese Laid-open Patent No. 55-46688.
FIG. 10 is a block diagram showing a portion of one channel of a conventional video signal output circuit composed of plural primary color signal output circuits.
In FIG. 10, a primary color video signal 101 is applied to a clip circuit composed of a Zener diode 103. An inverting amplifier composed of a power supply unit 104, a resistance 105, a transistor 106, and a resistance 107, through a circuit 102 aligns the black level of each primary color video signal for the display element (not shown), and adjusts white balance of the signal at specified brightness (hereinafter called cutoff/drive adjusting circuit).
The clip circuit is for clipping the signal at a specific constant level, before inputting the signal into the inverting amplifier, so as to not spoil the linearity of the output signal, by not excessively driving the inverting amplifier. Excessive driving of a succeeding video signal processing circuit and a succeeding display element are also prevented.
The operation of the video signal output circuit is described below.
FIG. 11A, FIG. 11B, and FIG. 11C show a conceptual diagram of an input signal and an output signal of the video signal output circuit. More specifically, FIG. 11A shows a signal waveform diagram when the clip circuit is not used, and FIG. 11B shows an expected signal waveform diagram when the clip circuit is used.
The clip circuit clips the video signal so that the succeeding video signal processing circuit and display element may not be driven excessively.
The saturation level LS shown in FIG. 11A and FIG. 11B refers to the peak value of maximum signal voltage that can be processed by the inverting amplifying circuit, succeeding video signal processing circuit, and display element. Clipping is done at a level within this saturation level LS.
The cutoff level LC refers to the black level of display element.
Initially, the Zener diode was used in the clip circuit for the purpose of utilizing the feature produced by the Zener characteristic, that is, when exceeding the Zener voltage, the Zener current is raised very violently, so that a constant voltage is obtained.
In this circuit, however, depending on the characteristic of the Zener diode, the picture is blunted near the clip level.
Individual Zener diodes are not always identical in characteristics. Therefore, clipping may differ depending on the individual difference of characteristics of Zener diodes.
In commercial Zener diodes, the inverse bias voltage, when passing a specified current to the diode, is controlled very well. A specified narrow width of a voltage is shown. However, in the region of current smaller than the specified current, the diode inverse bias voltage is not controlled, and the fluctuation width of the voltage is wide. Although the leak current of the Zener diode is a lower value than the specified current, some current is flowing and is not controlled. This is because the leak current of the Zener diode may not be an important control item in manufacture as long as this value is below the specified value.
When a Zener diode is used in a clip circuit, the leak current increases before the Zener potential of the Zener diode is reached. The waveform of the primary color video signal 101 begins to be blunted at a lower voltage than actually clipped. Thus, linearity of the signal is broken. FIG. 11C shows a blunt profile of a wave form when clipped by the Zener diode. Ideally, the primary color video signal 101 is clipped in the portion higher than the Zener voltage.
Depending on the variations of characteristics of the Zener diodes being used, however, the manner of collapse of linearity of the video signal differs in each channel, which may possibly lead to collapse of linearity of the white balance signal in the high luminance region.
SUMMARY OF THE INVENTION
A primary color video signal output circuit in accordance with an exemplary embodiment of the invention comprises, in order to limit the excessive input of video signal, a clip circuit for clipping the signal by a transistor, a reference voltage generating circuit for defining the clip voltage, and an amplifying circuit for driving the display elements. Thus, the primary color video output circuit solves the problem of collapse of the white balance signal at high luminance experienced in the conventional circuit.
That is, the clip circuit in accordance with the present invention severely limits the flow of leak current in a low voltage region below the clip voltage, and passes the current steeply when the video signal is at a voltage above the clip voltage, thereby clipping securely.
As a result, the peak value of video signal can be cut sharply. Thus, the primary video output circuit prevents deviation of white balance and color saturation (color distortion) signals in the high luminance region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a primary color video signal output circuit according to a first exemplary embodiment of the invention.
FIG. 2A is a primary color video signal waveform diagram before clipping in the first exemplary embodiment of the invention.
FIG. 2B is a clipped primary color video signal waveform diagram in the first exemplary embodiment of the invention.
FIG. 2C is a primary color video signal waveform diagram preceding the display element in the first exemplary embodiment of the invention.
FIG. 3 is a block diagram of a primary color video signal output circuit according to a second exemplary embodiment of the invention.
FIG. 4 is a block diagram of a primary color video signal output circuit according to a third exemplary embodiment of the invention.
FIG. 4A is a block diagram of a primary color video signal output circuit according to a further exemplary embodiment of the invention.
FIG. 5 is a block diagram of a primary color video signal output circuit according to a fourth exemplary embodiment of the invention.
FIG. 5A is a block diagram of a primary color video signal output circuit according to another exemplary embodiment of the invention.
FIG. 6 is a block diagram of a CRT display using a primary color video signal output circuit according to a fifth exemplary embodiment of the invention.
FIG. 7 is a block diagram of a television receiver using a primary color video signal output circuit according to a sixth exemplary embodiment of the invention.
FIG. 8 is a block diagram of a liquid crystal display using a primary color video signal output circuit according to a seventh exemplary embodiment of the invention.
FIG. 9 is a block diagram of a plasma display using a primary color video signal output circuit according to an eighth exemplary embodiment of the invention.
FIG. 10 is a block diagram of a primary color video signal output circuit in accordance with the prior art device.
FIG. 11A is a conventional signal waveform diagram without a clip circuit.
FIG. 11B is a conventional signal waveform diagram including a clip circuit.
FIG. 11C is a conventional conceptual diagram of blunting a waveform when clipped by a Zener diode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Exemplary Embodiment
A first exemplary embodiment of primary color video signal output circuit in accordance with the present invention is described while referring to FIGS. 1, 2A, 2B, and 2C.
In FIG. 1, a primary color video input signal 001 enters the base electrode of an inverting amplifying transistor 006 composing an inverting amplifier together with a power supply unit 004, a collector load resistance 005, and an emitter resistance 007.
The inverting amplifier inverts and amplifies the primary color video input signal 001, and delivers a primary color output video signal 008 for driving a display element (not shown).
The emitter electrode of a clip transistor 003 working as a clip circuit is connected to the base circuit of the inverting amplifier, and the collector electrode is grounded. That is, the clip circuit composed of the clip transistor 003 and a reference voltage generating circuit 002 is inserted so as to shunt the base circuit of the inverting amplifying transistor 006 for composing the inverting amplifying circuit.
A reference voltage is supplied to the base electrode of the clip transistor 003 from the reference voltage generating circuit 002.
If the amplitude of the primary color video input signal 001 exceeds the voltage defined by the reference voltage generating circuit 002, the clip transistor 003 conducts, and the primary color video input signal 001 is clipped.
FIG. 2A shows a primary color video signal waveform applied to the inverting amplifying transistor 006 when clip circuit is not provided. FIG. 2B shows a primary color video signal waveform applied to the inverting amplifying transistor 006 when the clip transistor 003 of the clip circuit is used. FIG. 2C shows a display element driving primary color video signal waveform delivered from the inverting amplifying circuit.
In FIGS. 2B and 2C, L1 and L2 represent variable clip levels, showing that the variable range of the reference voltage supplied from the reference voltage generating circuit 002 in FIG. 1 can be changed from L1 to L2. Also in FIG. 2C, LS represents the saturation level, which is the peak value of the maximum signal voltage delivered when the display element begins to show distortion. LC indicates the cutoff level, showing the black level of the display element.
In such constitution, when the voltage of the primary color video signal is below the reference voltage, the clip circuit does not operate at all, and the primary color video signal output circuit is in a state which is the same as when the clip circuit is not provided.
The clip circuit begins to operate only when the voltage of the primary color video signal exceeds the reference voltage.
When the voltage of the primary color video signal exceeds the reference voltage, the exceeded voltage is divided between the source output resistance of the signal entering the inverting amplifying transistor 006 and the resistance indicated by the clip transistor 003.
Of course, as compared with the former, the latter shows an extremely low value, and hence the primary color video signal is clipped at this level.
In the case of a transistor, the reverse current is extremely low as compared with the forward current, and while the voltage is applied in the reverse direction, the current flowing in the reverse direction can be completely ignored. Therefore, by making use of the forward characteristic of a transistor in a clip circuit, the clip circuit can clip the signal sharply.
Moreover, by varying the reference voltage supplied from the reference voltage generating circuit, an arbitrary clip level can be adjusted.
Second Exemplary Embodiment
A second exemplary embodiment of a primary color video signal output circuit in accordance with the present invention is described while referring to FIG. 3.
In FIG. 3, except for a band gap voltage source 012, the same circuit elements as in FIG. 1 operate similarly, and duplicated explanations are omitted.
The band gap voltage source 012 generates a constant voltage, not depending so much on the supply voltage or temperature fluctuations as disclosed in Japanese Laid-open Patent H7-230332 or Japanese Laid-open Patent H8-36435, so that the signal can be clipped at a higher precision.
The embodiment presents a primary color video signal output circuit which supplies a voltage from the band gap voltage source 012 into the reference voltage generating circuit 002, and therefore a clip voltage of high precision can be obtained.
In this constitution, if the supply voltage or temperature fluctuates due to variations of peripheral elements in mass production, the once set clip level is hardly changed, and it is effective to avoid color saturation (color distortion) and white balance signal deviation due to fluctuations of clip level caused by time-course changes or condition changes.
Third Exemplary Embodiment
A third exemplary embodiment of a primary color video signal output circuit in accordance with the present invention is described while referring to FIG. 4.
In FIG. 4, except for a power source 023 for supplying a reference voltage which is divided between resistance 024 and resistance 025 and which is applied to the base terminal of a clip transistor 026, the same circuit elements as in FIG. 1 operate similarly, and duplicated explanations are omitted.
As mentioned also in the first embodiment, FIG. 4 shows an example of setting the reference voltage at a desired value, not limited by the power source voltage applied to the reference voltage generating circuit.
The power source 023 may be a band gap voltage source shown in FIG. 3, or other power source as far as it is stable. The voltage of the power source is divided by the resistance 024 and the resistance 025 into an optimum value for setting the clip level. The divided voltage is supplied into the base electrode of the clip transistor 003.
In FIG. 4A, a cutoff/drive adjusting circuit 042 is a circuit for adjusting the cutoff voltage of the display element and aligning the black levels of primary color driving signals, and for adjusting the voltage of each primary color driving signal so that the primary color driving signal is balanced in white at an arbitrary voltage. In addition, a variable voltage source 032 replaces the power source 023. In all other respects the same circuit elements as in FIG. 4 operate similarly, and duplicated explanations are omitted.
In this constitution, the reference voltage can be selected arbitrarily, that is the reference voltage may be adjustable. Thus, the precision of the reference voltage can be enhanced and fluctuations of the reference voltage can be kept to a minimum limit.
Fourth Exemplary Embodiment
A fourth exemplary embodiment of a primary color video signal output circuit in accordance with the present invention is described while referring to FIG. 5.
In FIG. 5, except for a cutoff/drive adjusting circuit 042, the same circuit elements as in FIG. 1 operate similarly, and duplicated explanations are omitted.
The cutoff/drive adjusting circuit 042 is a circuit for adjusting the cutoff voltage of the display element and aligning the black levels of primary color driving signals, and for adjusting the voltage of each primary color driving signal so that the primary color driving signal is balanced in white at an arbitrary voltage.
In FIG. 5A, except for a band gap voltage source 012 described in the second exemplary embodiment, the same circuit elements as in FIG. 5 operate similarly, and duplicated explanations are omitted.
In such constitution, after the cutoff/drive adjustment, the video signal is clipped, and hence the precision of clip operation is high, and the clip level is not changed if the adjustment of cutoff/drive is changed.
Fifth Exemplary Embodiment
A display device using a CRT, comprising the primary color video signal output circuit according to an exemplary embodiment of the invention, is described while referring to FIG. 6.
FIG. 6 shows R, G and B primary color video signal output circuits 054, 055, and 056 for receiving R, G, and B primary color video input signals 051, 052, and 053, and delivering primary color video signals for driving a CRT 057.
Each primary color video signal output circuit is the primary color video signal output circuit including the clip circuit as described in the first, second, third or fourth embodiments.
Thus, the primary color video signal output circuit of the invention can be used in the CRT display, and the effects mentioned in the first, second, third or fourth embodiments can be obtained.
Sixth Exemplary Embodiment
A display device using a liquid crystal display element, comprising the primary color video signal output circuit according to an exemplary embodiment of the present invention, is described while referring to FIG. 8.
In FIG. 8, R, G and B primary color video input signals 071, 072, and 073 are fed into primary color video signal output circuits 074, 075, and 076, and delivered to a succeeding driving circuit 077.
The driving circuit 077 processes the video signal so as to drive a liquid crystal display element 078, and delivers to the liquid crystal display element 078.
The primary color video signal output circuits 074, 075, and 076 are the primary color video signal output circuits of the invention including the clip circuits as described in the first, second, third and fourth embodiments.
Thus, the primary color video signal output circuit of the invention can be used in the liquid crystal display, and the effects mentioned in the first, second, third or fourth embodiments can be obtained.
Seventh Exemplary Embodiment
A display device using a plasma display element, comprising the primary color video signal output circuit according to an exemplary embodiment of the present invention, is described while referring to FIG. 9.
In FIG. 9, R, G and B primary color video input signals 081, 082, and 083 are fed into primary color video signal output circuits 084, 085, and 086, and delivered to a succeeding driving circuit 087.
The driving circuit 087 processes the video signal so as to drive a plasma display element 088.
The primary color video signal output circuits are the primary color video signal output circuits of the invention including the clip circuits as described in the first, second, third and fourth embodiments.
Thus, the primary color video signal output circuit of the invention can be used in a plasma display, and the effects mentioned in the first, second, third or fourth embodiments can be obtained.
Eighth Exemplary Embodiment
A television receiver using the primary color video signal output circuit according to an exemplary embodiment of the invention is described below while referring to FIG. 7.
In FIG. 7, a television carrier signal 061 entered from an antenna is selected and detected in a tuner 062, and the detected video signal is fed into a video signal processing circuit 063.
The video signal processing circuit 063 demodulates the video signal and delivers R, G and B primary color video signals. Succeeding primary color video signal output circuits 064, 065, and 066 to which the R, G and B primary color video signals are fed, and a CRT 067 are same as shown in FIG. 6.
The succeeding primary color video signal output circuits, and the display are same as in the first, second, third, and fourth embodiments.
In FIG. 7, the CRT is used as the display element, but it is applicable to other display elements, such as liquid crystal display elements and plasma display elements.
Thus, the primary color video signal output circuit according to an exemplary embodiment of the invention can be used in the television receiver. | A primary color video output circuit for limiting an input video signal. The circuit includes a clipping circuit, a reference voltage generating circuit and an amplifier. The clipping circuit limits the level of the input video signal based on a reference voltage generated by the reference voltage generating circuit. The amplifier is then used to amplify the clipped video signal. | 6 |
This is a continuation of co-pending application Ser. No. 832,216, filed on 2-14-86, now abandoned.
BACKGROUND OF THE INVENTION
In the last decade there has been increasing use of percutaneous transluminal balloon angioplasty for the opening of stenoses of the peripheral and coronary arteries. In this procedure the uninflated balloon at the tip of the catheter is advanced into the narrowed portion of the arterial lumen. The balloon is then inflated so as to push the stenotic plaque outward thereby enlarging the luminal diameter and improving distal perfusion. The balloon is then deflated and the catheter is withdrawn from the body. Initially the blood flow at that point is typically improved to a significant degree. However, within six months, restenosis, defined as a loss of more than 50% of the initial enlargment of arterial diameter, occurs in approximately 30% of cases. It would therefore be of great value if a means could be devised to retain patency (i.e. opening) of the artery so that adequate blood flow would be maintained.
The concept of placing a coil spring intravascular stent within an artery is not new. In the September-October 1969 edition of Investigative Radiology, C. T. Dotter reported the insertion of 6 coil spring intravascular stents in the arteries of dogs. Three of these springs which were covered with silicone rubber occluded within 24 hours. Two out of three, bare stainless steel wire springs remained patent at 21/2 years. Dotter also described a "pusher-catheter" of equal diameter with the spring outer diameter which was used to place the springs within the artery.
In more recent work, D. Maas et al in the September 1984 edition of Radiology described improved stainless steel coil spring intravascular stents that were implanted in 65 dogs and 5 calves. A 100% success rate was reported using bare, heat treated steel alloy springs that were torqued to a reduced diameter and inserted with a special device designed for that purpose.
Neither Dotter nor Maas at all were able to perform a percutaneous procedure for the stent insertion. Dotter describes a "pusher-catheter" that was of equal diameter to the outside diameter of the coil spring. Maas et. al. used a 7 mm diameter special insertion device that applied torque to the coil spring to reduce its diameter to 7 mm; i.e., the deployed outside diameter was greater than 7 mm. Since the largest practical outside diameter for percutaneous delivery is less than 4 mm, the device and methods used by Maas et al are not practical for percutaneous insertion.
The results of Dotter i.e. 2 of 3 patent arteries at the end of 21/2 years using comparatively small (3.5 mm) diameter coil are probably not good enough for clinical applications. The results of Maas et al were very good, but these were for inside diameters greater than 7 mm.
What is really needed and not described by either Dotter or Maas et al or anyone else is a safe and simple method for percutaneous transluminal insertion of a coil spring stent whose insertion device structure allows an insertion catheter of outer diameter less than 4 mm. Another requirement of the insertion device is that it maintains the reduced diameter of the coil spring stent during insertion and allows the coil to expand to a diameter greater than the diameter of the arterial lumen after removal of the insertion catheter.
To make the intravascular stent (IS) safe for human use even in small diameter coronary arteries, it is necessary for the spring material to be biocompatible and non-thrombogenic. The greatest success by Dotter and Maas et al was with bare metal coil springs. However, no investigation to date has described use of these stents in either human subjects or in animal coronary arteries. Furthermore, Dotter quotes an article which states that "It appears that success or failure of an arterial substitute in dogs bears no direct relationship to the results one will obtain when a similar substitute is used clinically for the peripheral arteries". Hence one must be concerned with the human biocompatability of the material used for the IS.
Many articles such as "ULTI Carbon Goretex: A New Vascular Graft" by R. Debski et al in the May-June 1983 edition of Current Surgery describe the superior non-thrombogenic characteristics of ultra low-temperature isotropic (ULTI) carbon as such a blood compatible material. The use of carbon as a blood compatible material for humans is well known among those skilled in the art of vascular grafts and prosthetic heart valves. However, no investigator of IS devices has ever described the use of carbon coated coil springs or carbon coated polytetrafluoroethylene (PTFE) covered coil springs to solve the problem of thrombosis of small diameter IS devices in humans.
It should be noted that nothing in the prior art describes the use of a coil spring stent for the prevention of arterial blockage due to intimal dissection (tearing away of the intima layer) following balloon angioplasty. There is appproximately a 30% incidence of radiologically detectable intimal dissection following routine percutaneous transluminal coronary angioplasty (PTCA). In many of these cases this is not a problem. Vessel wall healing and remodeling typically restores a smooth luminal contour with good vessel patency within several weeks following the angioplasty. In a small but significant subset of these patients, the intimal dissection may be severe, resulting in a high risk of vessel closure within 24 hours following PTCA. These patients will typically sustain some degree of myocardial infarction despite further aggressive attempts at revascularization, including coronary artery bypass surgery.
SUMMARY OF THE INVENTION
Thus it is an objective of the present invention to utilize a coil spring intravascular stent (IS) for the prevention of arterial restenosis.
A second objective of the invention is to utilize an IS to further enlarge the luminal diameter after successful percutaneous transluminal angioplasty.
Another objective is to provide a percutaneous transluminal catheter means for placing the IS at the appropriate place within the artery.
Still another objective is to describe a method for percutaneous insertion of intravascular stents.
Still another objective is to provide a means and method for preventing arterial blockage due to intimal dissection following balloon or other types of angioplasty.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C are cross-sectional views showing respectively the shape of the plaque within an arterial wall, (A) before balloon dilation, (B) immediately after balloon dilation, and (C) at several months after dilation.
FIG. 2 is a cross-sectional view of an IS in the form of a coil spring placed in a position to prevent restenosis and/or provide additional dilation of the plaque.
FIG. 3 is a cross-sectional view of the distal end of an insertion catheter for inserting the IS.
FIG. 4 is a cross-sectional view of the proximal end of the insertion catheter.
FIG. 5 is a cross-sectional view of a wire coated with ULTI carbon.
FIG. 6 is a cross-sectional view of a wire enclosed by PTFE and coated with ULTI carbon.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A, 1B and 1C are cross-sectional views of an arterial wall AW surrounding a plaque P which forms an arterial stenosis or narrowing. It is well known in the art to utilize percutaneous transluminal balloon angioplasty to dilate the stenosis of FIG. 1A by expanding a balloon that is placed within the narrowed lumen. The result immediately after balloon dilation is shown in FIG. 1B. However, in approximately 30% of all balloon procedures, there is a restenosis of the artery as illustrated in FIG. 1C.
If however, a coil spring intravascular stent (IS) 10 is placed at the dilation site immediately after balloon dilation in a position as shown in FIG. 2, the resistance of the IS 10 to deformation by inwardly directed radial pressure can preclude restenosis of the artery. Furthermore, if the constrained diameter of that IS 10 as shown in FIG. 2 is less then the free diameter of the coil spring IS 10, then additional dilation may occur following the insertion of the IS 10. Furthermore, if the intima layer was torn (i.e. dissected) during balloon dilation, the IS 10 can hold that intima layer in place and prevent subsequent blockage of the artery which can result from the effect of blood flow causing the torn intima to come off the wall of the dilated stenosis.
FIG. 3 shows the distal end of the insertion catheter 20 which consists of an inner core 22 and an outer cylinder 24. The core 22 has a rounded and tapered front end 23 and spiral grooves 26 into which the coil spring IS 10 is placed. The core 22 has a back groove 28 which contains the most proximal coil of the coil spring IS 10 which is prevented from springing radially outward by the flange 30.
FIG. 4 is a cross-sectional view of the proximal end of the insertion catheter 20. A cylindrically shaped cylinder handle 32 is molded onto the outer cylinder 24. Similarly, a cylindrically shaped core handle 36 is molded onto the core 22. A conically shaped interior surface 34 of the cylinder handle 32 is used to help guide the cylinder handle 32 over the IS 10 as it is mounted on the distal end of the insertion catheter 20. The distance D in FIG. 4 is initially set to be slightly greater than the length of the IS 10 at the distal end of the insertion catheter 20.
The spring IS 10 is loaded onto the distal end of the core in the following manner:
1. A pair of pliers is used to hold the most distal portion of the IS 10 into the most distal spiral groove 26 of the inner core 22.
2. The spring IS 10 is then pulled and twisted applying torque to its most proximal end so that the spring IS 10 is forced into the spiral grooves 26.
3. A pliers wide enough to hold all turns of the IS 10 in place except the most proximal turn and the most distal turn is then applied at the center of the IS 10 to hold it in the spiral grooves 26.
4. A needle nose pliers is then used to force the most proximal turn of the IS 10 into the core groove 28.
5. The conical interior surface 34 of the cylindrical handle 32 is then fed over the most distal turn of the IS 10 as it sits in the most distal groove 26 of the core 22.
6. As the handle 32 is moved in the proximal direction, the broad pliers holding the central portion of the IS 10 in place is simultaneously moved in the proximal direction until the entire IS 10 is covered by the interior surface of the handle 32 and the outer cylinder 24.
7. The handle 32 is then pulled in a proximal direction until the distal end of the cylinder 24 lies just over the last turn of the IS 10 which occurs when the cylinder handle 32 and the core handle 36 are separated by a distance D as shown in FIG. 4.
In this manner, a coil spring IS 10 whose unrestrained (i.e. free) diameter can be between 1.1 to 5.0 times larger than its diameter when stored on the core 22 can be placed at the distal end of the insertion catheter 20.
Deployment of the spring IS 10 within a recently dilated occlusion is accomplished in the following steps:
1. By conventional means, a guiding catheter (not shown) is placed percutaneously into the femoral artery and its distal end is advanced to the site where the IS 10 is to be released.
2. Under fluoroscopic control, the insertion catheter 20 is advanced through the guiding catheter until the center of the IS 10 is positioned at the center of the recently dilated stenosis.
3. While holding the core handle 36 firmly against the body so that it does not move, the outer cylinder handle 32 is move proximally so as to decrease to zero the distance D of FIG. 4.
4. All turns of the IS 10 except the most proximal turn are then expanded outward to engage the interior surface of the recently dilated stenosis.
5. The core 22 and the outer cylinder 24 are then pulled out of the body together which leaves the coil spring IS 10 in its desired place in the artery.
An angioplasty balloon could then be expanded within the IS 10 so as to more firmly imbed the spring into the stenotic plaque. The balloon and guiding catheters would of course be removed from the body after they were used for their intended purposes.
The coil spring used in this manner would:
1. Prevent restenosis of the occlusion.
2. Increase the lumen diameter by constantly applying an outward radial force to the plaque, and
3. Hold in place any intima layer torn from the stenosis during balloon dilation which might otherwise tend to block blood flow in that artery.
The materials of the core 22, core handle 36, outer cylinder 24 and outer cylinder handle 32 might be PVC or some other comparatively strong plastic. The IS 10 might be fabricated from a stainless spring steel or an alloy of titanium such as Ti-6A1-4V. The outside diameter of the unrestrained coil spring IS 10 might vary from 2 to 12 mm depending on the lumen diameter into which it is implanted. The wire diameter might be between 0.1 and 0.5 mm. The outer diameter of the outer cylinder 24 would be less than 4 mm. The length of the IS 10 would be between 5 and 25 mm depending upon the length of the dilated stenosis into which it would be placed.
Decreased thrombogenicity can be achieved by coating the outside of the coil with a non-thrombogenic material such as ULTI carbon. An enlarged cross section of such a wire is shown in FIG. 4. The metallic core is shown as 40 and the coating is shown as 42. Coating thickness might be as thin as 0.01 mm or as thick as 0.1 mm.
FIG. 5 shows another enlarged cross section of the wire of the IS 10 in which the metallic core 40 is first covered by a plastic layer 44 such as PTFE and then coated with a nonthrombogenic coating 46 such as ULTI carbon. The plastic coating would typically be between 0.05 and 0.5 mm and the non-thrombogenic coating might have a thickness between 0.01 and 0.5 mm.
Although this intravascular stent might find its greatest application as a means to enhance balloon angioplasty in humans it could also be used to successfully provide permanent dilation and patency of other ducts and vessels within a living human or animal body. For example, this coil spring intravascular stent 10 could also be used to maintain long term patency of ureters or fallopian tubes. In every use, the fact that wire diameter would be typically 1/10 the coil spring pitch length i.e., only 10% of the lumen interior surface is actually in contact with a foreign material. Therefore, normal body cells could grow over the coils of such springs. Thus, the normal characteristics of the interior lining of such ducts or vessels would be only minimally compromised.
Various other modifications, adaptations, and alternative designs are, of course, possible in light of the above teachings. Therefore, it should be understood at this time that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | This invention is in the field of percutaneous insertion catheters that are used for placing a coil spring stent into a vessel of a living body for the purposes of enhancing luminal dilation, preventing arterial restenosis and preventing vessel blockage resulting from intimal dissection following balloon and other methods of angioplasty. The stent can also be used for the maintaining patency of many different ducts or vessels within a living body. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of International Patent Application No. PCT/CN2012/076102 with an international filing date of May 25, 2012, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201210123601.2 filed Apr. 25, 2012, and to Chinese Patent Application No. 201210123590.8 filed Apr. 25, 2012. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P.C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18 th Floor, Cambridge, Mass. 02142.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a small peptide and specifically to imaging and treatment of a non-small cell lung cancer.
[0004] 2. Description of the Related Art
[0005] Lung cancer is one of the most common cancers and is the leading cause of cancer death worldwide. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. There are three types of cancer that are considered NSCLC including adenocarcinoma, squamous cell carcinoma (SCC), and large cell undifferentiated carcinoma. Approximately three quarters of patients with lung cancer have an advanced stage of tumor at the time of diagnosis. The most recent statistics show the overall five-year survival of lung cancer is about 10% to 16% in the United States, Europe and China after diagnosis. The survival of lung cancer is heavily dependent on early diagnosis. For example, 5-year survival of Stage IA/B lung cancer is approximately 70% and for Stage IIA/B disease is in the range of 50% when patients are eligible to receive surgery. Therefore, early detection improves apparent survival of lung cancer patients, even if mortality remains unchanged.
[0006] Globally, imaging such as PET/CT or single-photon emission computed tomography (SPECT) remains the most effective methods for lung cancer detection. Unfortunately, these current scanning modalities are not sufficiently sensitive or specific to clearly determinate between benign and malignant solitary pulmonary nodules. The false-positive imaging may happen in inflammation (e.g., pneumonia and active tuberculosis) and granulomatous disease (e.g., sarcoidosis and Wegener's granulomatosis) because these pulmonary nodules have the same high uptake of FDG as malignancy. Meanwhile, limitations of PET/CT for evaluating lung nodules are a reduction in specificity and increased false negatives in very small tumors or those with low FDG uptake (e.g., bronchoalveolar carcinomas) (Maffione A M, et al. J Nucl Med. 2014; 55: 983-988). SPECT is widely available, has lower costs than PET/CT, and does not require the presence of a cyclotron adjacent to the hospital. Encouraging results have been obtained with SPECT scanning using sestamibi to detect primary lung malignancies and to perform mediastinal staging with a higher diagnostic accuracy higher than chest CTs. However, the main difficulty is related to the limited spatial resolution of SPECT. To overcome the limited resolution of SPECT, many investigators are working on developing novel sensitive and specific radiotracers for SPECT.
[0007] Application for molecularly targeted agents in a non-small cell lung cancer (NSCLC) has witnessed swift evolution in the last decade. These targeted anticancer agents promise more efficient and less toxic side effects for patients as compared with common chemotherapeutic agents. The EGF receptor (EGFR) is therapeutically targeted by antibodies (Cetuximab) and small molecules (Iressa, erlotinib) in solid tumors including lung, colorectal, and breast cancer. However, a small percentage of patients (21%) with an EGFR mutation have higher response rates and all patients eventually develop resistance. Another promising approach has been obtained in radioimmunotherapy (RIT) for the treatment of B-cell non-Hodgkin's lymphoma with yttrium-90 ( 90 Y)-ibritumomabtiuxetan (Zevalin) and iodine-131 ( 131 I)-tositumomab (Bexxar). 131 I-chTNT is the first approved clinical trial radiolabeled antibody for the treatment of solid tumors including lung cancer, glioblastoma, head and neck cancer, colorectal carcinoma, hepatocellular carcinoma, etc. However, the response rate (ORR) was only 33% in non-small-cell lung cancer patients (Chen S, et al. J Clin Oncol. 2005; 23: 1538-47). 131 I-chTNT was iodine-131—labeled recombinant human and mouse chimeric TNT antibody and has potential allergen. It is, therefore, essential to seek more effective and less toxic modes of therapy for advanced lung cancer.
SUMMARY OF THE INVENTION
[0008] In certain embodiments, this invention is directed to a peptide comprising 8 animo acids with the sequence of cXGXGXXc for NSCLC cells. c represents d-cysteine (Cys) on the N- and C-termini providing intra-molecular cyclization by disulfide bonding. G represents L-Glycine (Gly). X is selected from any one of the 20 standard amino acids.
[0009] In certain preferred embodiments, this invention is directed to a pharmaceutical composition comprising a peptide with the sequence cNGEGQQc (SEQ ID NO.1) as a pharmaceutically acceptable carrier of the compound of formula. c represents d-cysteine (Cys). N represents L-Asparagine (Asn). G represents L-Glycine (Gly). E represents L-Glutamic acid (Glu). Q represents L-Glutamine (Gln). In other aspects, the invention is directed to methods of molecular imaging probe for non-small cell lung cancer. The peptide stated above was labeled with Technetium-99m ( 99m Tc) to generate 99m Tc-cNGEGQQc. For evaluation as a SPECT imaging agent, the labeled compounds were then tested for the imaging of H1975 (adenocarcinoma) and L78 (squamous carcinoma) xenograft tumors in mice.
[0010] In other aspects, the invention is directed to methods of targeting radiotherapeutic agent for non-small cell lung cancer. The peptide stated above was labeled with iodine-131 to generate 131 I-cNGEGQQc. The labeled peptides were then evaluated in mice for the therapeutic effects of H1975 and L78 xenograft tumors.
[0011] This invention relates to a novel peptide comprising 8 animo acids with the sequence of cNGEGQQc that specifically recognizes cells of human NSCLC. Further, this invention relates to a pharmaceutically targeted carrier for delivery of imaging agents and therapeutics to NSCLC. More specifically, the peptide of this invention is applied to combine 99m Tc as specific imaging probe and to combine 131 I as targeting radiotherapeutic agent in the imaging and treatment of non-small cell lung cancer.
[0012] Peptide of this invention may be used in combination with known imaging agents. The imaging agents comprise 99m Tc, 111 In, 18 F-FDG, 68 Ga, 64 Cu.
[0013] Generally, molecular imaging probe is prepared according to the following manner.
[0014] First, the peptide of the invention was synthesized commercially in their native L configurations with an amino hexyl linker on the terminal amine for conjugation and provided at 97% purity as determined by reversed-phase high-performance liquid chromatography (RP-HPLC).
[0015] The peptide prepared above was then conjugated to a chelator of S-acetyl-mercaptoacetyltriglycine (MAG 3 ) to produce peptide-MAG 3 complex and subsequently labeled by 99m Tc. For conjugation of the peptide with 99m Tc, the following methods were described by Wang Y et al (Wang Y, et al. Nat Protoc. 2006; 1: 1477-80).
[0016] Synthesis of SATA. S-acetyl mercaptoacetic acid was synthesised under optimum conditions from mercaptoacetic acid and acetic anhydride. SATA was further obtained when S-acetyl mercaptoacetic acid was reacted with the same molar equivalent of NHS ester via DCC.
[0017] Synthesis and Labeling of peptide-MAG3. Peptide was prepared by solid-phase synthesis and conjugated to MAG3. The peptide-MAG3 (10 mL of a mg/mL solution) were labeled with technetium-99m using labeling buffer (0.25 mol/L Sodium Bicarbonate, 0.125 mol/L ammonium acetate, 0.18 mol/L ammonium hydroxide, 1:1:1). The reaction was induced by heating the mixture to 100° C. for 20 min.
[0018] Peptide of this invention may be used in combination with known radiotherapeutic agents. The radiotherapeutic agents comprise 131 I and 125 I.
[0019] Generally, radiotherapeutic agent is prepared according to the following manner.
[0020] The N-terminal of peptide prepared above was coupled to C-terminal of tyrosine by condensation reaction with EDC-HCl (1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride amine). The reaction time was 2 hours at room temperature.
[0021] The complex was subsequently reacted with 131 I (37 MBq/20 μl) by adding chloramine T (final concentration 0.9 μg/μl) and stopped by adding 45 μl (4 μg/μl) of sodium thiosulfate. The reaction time was 2 minutes at room temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows mass spectrometry (MS) analysis of cNGEGQQc-MAG3;
[0023] FIG. 2 shows high performance liquid chromatography (HPLC) analysis of cNGEGQQc-MAG3;
[0024] FIG. 3 shows stability testing of molecular imaging probe 99m Tc-cNGEGQQc by paper chromatography (A. acetone system; B. ammonia/ethanol/water mixture system);
[0025] FIG. 4 shows biodistribution of 99m Tc-cNGEGQQc in mice;
[0026] FIG. 5 shows biodistribution of 99m Tc-cNGEGQQc in rabbits by SPECT scanning for one minute (1 frame/second);
[0027] FIG. 6 shows biodistribution of 99m Tc-cNGEGQQc in rabbits by SPECT scanning for 5 minutes (1 frame/second);
[0028] FIG. 7 shows biodistribution of 99m Tc-cNGEGQQc in rabbits by SPECT scanning for 30 minutes (1 frame/5 minutes);
[0029] FIG. 8 shows the time-radioactivity curves of heart, liver, spleen, kidney and bladder were measured using the region-of-interest (ROI)-based analysis by injection of 99m Tc-cNGEGQQc (1. the time-radioactivity curve from ROI analysis after dynamic recording in major organs of normal rats; 2. the time-radioactivity curve of heart; 3. the time-radioactivity curve of spleen; 4 the time-radioactivity curve of liver; 5. the time-radioactivity curve of kidney; 6. the time-radioactivity curve of bladder);
[0030] FIG. 9 shows the anterior and rear images were acquired by SPECT scanning after 1.5 h intravenous injection of 99m Tc-cNGEGQQc;
[0031] FIG. 10 shows SPECT imaging of mice bearing L78 tumors were obtained after intravenous injection of 99m Tc-cNGEGQQc at different time (arrows show tracer uptake in the tumors);
[0032] FIG. 11 shows SPECT imaging of mice bearing H1975 tumors were obtained after intravenous injection of 99m Tc-cNGEGQQc (arrows show tracer uptake in the tumors). (A, after 2 h injection of 99m Tc-cNGEGQQc; B, after 2 h injection of 99m Tc-cNAQAEQ) (arrows show tracer uptake in the tumors);
[0033] FIG. 12 shows mass spectrometry (MS) analysis of cNGEGQQc-Tyr;
[0034] FIG. 13 shows the radiochemical purity (RCP) of 131 1-cNGEGQQc was analyzed by paper chromatography;
[0035] FIG. 14 shows radiochromatograms of 131 1-cNGEGQQc was analyzed by high performance liquid chromatography (HPLC);
[0036] FIG. 15 shows the time-radioactivity curves of heart, liver, spleen, kidney and bladder were measured using the region-of-interest (ROI)-based analysis by injection of 131 1-cNGEGQQc (1. the time-radioactivity curve from ROI analysis after dynamic recording in major organs of normal rats; 2. the time-radioactivity curve of heart; 3. the time-radioactivity curve of spleen; 4 the time-radioactivity curve of liver; 5. the time-radioactivity curve of kidney; 6. the time-radioactivity curve of bladder);
[0037] FIG. 16 shows the anterior and rear images were acquired by SPECT scanning after intravenous injection of 131 1-cNGEGQQc at different time (1-2, after 30 mins injection of 131 1-cNGEGQQc; 3-4, after 1 h injection of 131 1-cNGEGQQc; 5-6, after 3.5 h injection of 131 1-cNGEGQQc);
[0038] FIG. 17 shows growth curve of H1975 cells in nude mice; and
[0039] FIG. 18 shows growth curve of L78 cells in nude mice.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0040] The following experimental examples are provided in order to demonstrate and further illustrate the invention in detail. These examples are intended merely to illustrate the disclosed methods and products. However, the examples should not be construed as limiting in any manner
Example 1
Synthesis of cNGEGQQc (SEQ 1N NO.1) Using Solid-Phase Peptide Synthesis
[0041] First, one gram of the resin beads with NH 2 functional groups was swollen in dimethylformamide (DMF) and washed with water. After water was drained, d-cysteine and N,N′-diisopropyl carbodiimide were added to the beads. The reaction time was 2 hours at room temperature. Next, beads were washed with DMF for five times. A solution of 20% (v/v) piperidine in DMF was added to the beads. The reaction mixture was stirred for 15 min to allow the Fmoc deprotection.
[0042] The process for deprotection and coupling was then repeated until the last amino acid in the sequence was successfully coupled. After the beads were washed with 25% (v/v) trifluoroacetic acid once and distilled water three times, peptides were cleaved from the resin with anhydrous hydrogen fluoride (HF). A disulfide bond in peptides was formed between two cysteines by oxidation with iodine in 30% (v/v) acetic acid. The cleaved peptides were purified using gel filtration on Sephadex G-15 column, followed by high-performance liquid chromatographic purification (HPLC). The purified peptides showed a single major peak by RP-HPLC analysis.
Example 2
Preparation of Molecular Probe 99m Tc-cNGEGQQc for Imaging Lung Cancer
[0043] The purified peptides above were conjugated to S-acetyl-mercaptoacetyltriglycine (MAG 3 ) to produce peptide-MAG 3 complex. The theoretical molecular weight of the peptide is 1125.05 Da, while accurate molecular weight of the purified peptides was determined to be 1146.84 Da by mass spectrometry ( FIG. 1 ). The purity of peptides was monitored as 96% by HPLC ( FIG. 2 ). For conjugation of the peptide-MAG 3 complex, the procedure was performed according to the following manner.
[0044] 1) Synthesis of SATA. S-acetyl mercaptoacetic acid was synthesized from mercaptoacetic acid and acetic anhydride with 1:1.1 molar ratios at room temperature for 4 days. The high purity complex was obtained under reduced pressure (115-125° C., 2-3 mmHg). Both S-acetyl mercaptoacetic acid (75 mmol) and NHS (75 mmol) were dissolved in 150 mL of dioxane. After cooling on ice, dicyclohexylcarbodiimide (DCC) (75 mmol) in 10 mL of THF was added and the reaction mixture stirred for 16 h. The precipitated dicyclohexylurea was removed by filtration and the solvent evaporated to dryness under vacuum. The residue was crystallized twice with isopropanol.
[0045] 2) Synthesis of peptide cNGEGQQc-MAG3. Peptide cNGEGQQc was prepared by conventional solid-phase synthesis. During the synthesis, three glycines were coupled to the N-terminus of peptide. A one-fold molar excess of SATA was added into peptide solution with 7-fold molar excess of 3mDIEA (diisopropylethylamine) and 3-fold molar excess of HBTU (O-Benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate) and 3-fold molar excess of HOBT (1-hydroxybenzotriazole). The mixture was incubated at room temperature for 1 h. The reaction was done when Ninhydrin reaction showed in yellow colouration. After completing synthesis, the peptide resin was washed with NMP (N-methylpyrrolidone) and DCM (dichloromethane) alternately, removed from the column and dried in vacuo. The peptides were cleaved from the resins by treatment with mixture solution (1 mL of ethanedithiol, 1 mL of thioanisole, 0.5 g of phenol, 0.4 mL of H 2 O and 0.1 mL of triisopropylsilyl) for 7 h. The crude complex was precipitated with diethyl ether 4 times and separated by centrifugation and freeze dried. Purified complex was characterized by analytical HPLC. Conjugation of MAG3 using this protocol was done directly during the synthesis of cNGEGQQc.
[0046] Labeling cNGEGQQc-MAG 3 with 99m Tc was performed according to the reference (Winnard P, et al. Nucl Med Biol, 1997; 24: 425-432) with minor improvements. The conjugated peptides cNGEGQQc-MAG 3 (20 μg) were labeled with fresh 99m TcO4 − solution (37 MBq) using labeling buffer (0.25 mol/L of Sodium Bicarbonate, 0.125 mol/L of ammonium acetate and 0.18 mol/L of ammonium hydroxide). The reaction was incubated at 100° C. for 20 min.
[0047] We summarized the 5 important factors in the 4 different conditions for labeling peptide with 99m Tc (Table 1). The orthogonal design was carried out to optimize the experimental conditions for labeling (Table 2). The optimal labeling conditions by orthogonal design were as follows: final concentration of potassium sodium tartrate turn chelator of 3.5 μg/μL, 5 μg/μL of stannous tartrate and reaction conditions at pH 7.6 and 25° C. for 30 min.
[0000]
TABLE 1
Important factors for labeling peptide
Temperature
Time
Potassium sodium
Stannous
Level
(° C.)
(min)
pH
tartrate (μg/μL)
tartrate (μg/μL)
1
25
10
2.0
0.5
0.25
2
37
20
4.0
1
1
3
75
30
7.6
3.5
5
4
100
60
10.0
10
10
[0000]
TABLE 2
Orthogonal design of four factors for labeling peptide
Potassium
Stannous
Temperature
Time
sodium
tartrate
Labeling
No
(° C.)
(min)
pH
tartrate (μg/μL)
(μg/μL)
(%)
1
25
10
2.0
0.5
0.25
7.50%
2
25
20
4.0
1
1
85.60%
3
25
30
7.6
3.5
5
98.60%
4
25
60
10.0
10
10
89.50%
5
37
10
2.0
0.5
0.25
85.20%
6
37
20
4.0
1
1
89.90%
7
37
30
7.6
3.5
5
98.30%
8
37
60
10.0
10
10
91.50%
9
75
10
2.0
0.5
0.25
85.40%
10
75
20
4.0
1
1
91.50%
11
75
30
7.6
3.5
5
94.80%
12
75
60
10.0
10
10
97.70%
13
100
10
2.0
0.5
0.25
97.60%
14
100
20
4.0
1
1
89.10%
15
100
30
7.6
3.5
5
93.50%
16
100
60
10.0
10
10
10.50%
Example 3
Labeling Efficiency and Stability of Molecular Probe ( 99m Tc-cNGEGQQc)
[0048] Labeling efficiency of molecular probe was determined by paper chromatography. The details were as follow: A drop of the molecular probe was placed on one side of the paper, then dipped into a mixture liquid with ethanol:ammonia:water (2:1:5) (system 1) and acetone (system 2). The separation occurs as the liquid moves along the paper. Take the paper out and dry it when the liquid moves to the other side of paper. Paper was cut into ten equal pieces and put into the tube separately. The radioactivity of each pieces of paper was measured by radioactivity counter and calculated the percentage of radioactivity and labeling rate. (Radioactivity percentage=(radioactivity count/total radioactivity count)×100%) (Labeling rate=radioactive percentage of 99m Tc-labeled peptides−radioactivity percentage of 99m Tc). The peptides were labeled using optimal labeling conditions and measured by paper chromatography. The labeling rate of cNGEGQQc using 99m Tc ranged 84%-95%.
[0049] To evaluate the stability of molecular probe in vitro, radiochemical purity was measured using paper chromatography. The formula for radiochemical purity is radioactive percentage of 99m Tc-labeled peptides (system 1)−radioactivity percentage of 99m Tc (system 2). After purification with HPLC, the 99m Tc labeled cNGEGQQc was placed at room temperature for 24 h. The radiochemical purity was 95% at 0 h and 90% at 24 h respectively. The stability of 99m Tc labeled cNGEGQQc was further estimated in fresh human serum at 37° C. for 24 h. After 24 h incubation, 85% of 99m Tc labeled cNGEGQQc remained intact in serum. The radiochemical purity was 95% at 0 h and 85% at 24 h respectively. These data suggests that 99m Tc labeled cNGEGQQc is very stable in vitro ( FIG. 3 ).
Example 4
Biodistribution of Molecular Probe ( 99m Tc-cNGEGQQc) in Animals
[0050] Fifteen normal Kunming male mice (4-6 weeks old, weight 19-21 g) were injected with 0.1 mL (2.96 MBq) of 99m Tc-cNGEGQQc via a tail vein respectively. At 1, 3, 6, 12, and 24 h, three animals were anesthetized and sacrificed by cervical dislocation. Whole blood was collected and organs of interest were removed and weighed. The amount of radioactivity in blood and each organ was determined and calculate the percentage of the injected dose per gram of tissue (% ID/g). Subsequently, SPECT (Millennium VG; GE Healthcare) was equipped with a low-energy, high resolution collimator. Images were collected using energy peak centered at 140 KeV, an energy window of 20% and a 128×128 matrix at a magnification of 1.0. The biodistribution 99m Tc-cNGEGQQc in mice was shown in Table 3 and FIG. 4 . SPECT imaging showed that the radioactivity of kidney and liver was significantly higher than that of other organs in healthy mice. The uptake of molecular probe was more and clearance took longer in kidney than that in liver. These results showed that molecular probe mainly excreted by kidneys. During the observation period, the radioactivity of various organs gradually decreased, while the radioactivity of gastrointestinal was relatively stable. It indicated that the stability of molecular probe was excellent and no free 99m Tc release in vivo. Only little uptake of molecular probe was observed in lung and muscles. Therefore, it will be excellent for imaging of lung cancer patients because good background contrast to tumors.
[0000]
TABLE 3
Biodistribution of 99m Tc-cNGEGQQc in mice (% ID/g)
Tissues
1 h
3 h
6 h
12 h
24 h
liver
5.0643 ± 1.3116
3.5032 ± 01.4641
2.2112 ± 2.8001
1.8420 ± 0.5133
1.4979 ± 0.0196
spleen
1.7332 ± 0.1762
1.5724 ± 1.0061
0.9598 ± 1.1390
0.8098 ± 0.0330
0.7272 ± 1.1205
kidney
5.4965 ± 1.1285
6.9413 ± 2.12189
4.9006 ± 0.7596
3.0748 ± 0.3810
1.4445 ± 0.2331
lung
0.8558 ± 0.1760
0.5627 ± 0.4336
0.3496 ± 0.0457
0.2337 ± 0.1501
0.1148 ± 0.0137
stomach
0.2304 ± 0.0708
0.2442 ± 0.0857
0.1965 ± 0.1023
0.2326 ± 0.0691
0.2266 ± 0.0162
intestine
0.1059 ± 0.0296
0.1817 ± 0.0737
0.1427 ± 0.0550
0.1524 ± 0.0150
0.1367 ± 0.0256
muscle
0.1261 ± 0.0818
0.0920 ± 0.01511
0.0950 ± 0.0257
0.0691 ± 0.0185
0.0702 ± 0.0007
bone
0.2165 ± 0.1083
0.3969 ± 0.1026
0.2590 ± 0.1329
0.1524 ± 0.0315
0.1886 ± 0.0723
blood
0.7801 ± 0.3564
0.4845 ± 0.1010
0.2987 ± 0.1194
0.2387 ± 0.0666
0.1205 ± 0.0270
[0051] Biodistribution of Molecular Probe ( 99m Tc-cNGEGQQc) in Rabbits
[0052] Two of healthy Japanese male white rabbits were fixed in supine position on a wooden experimental stage. We set SPECT collimator on the rabbit thoracic and abdominal to ensure that the whole body of rabbit was within vision field of SPECT imaging. The injectant of molecular probe (0.5 mL/74 MBq) was administered through the ear vein injection. Images were acquired immediately and for the next 60 min at a rate of 1 frame/min after injection of molecular probe, followed a rate of 1 frame/2 min at 90 min, 120 min, 180 min and 240 min. The distribution of molecular probe in animal organs was observed at different time post injection. The posterior dynamic images were analyzed by ROI. The time-radioactivity curves of main organs comprising precordia, liver, spleen, kidney and bladder were obtained respectively by ROI analysis ( FIGS. 5-9 ).
Example 5
Evaluation of Molecular Probe ( 99m Tc-cNGEGQQc) in Mice Bearing Lung Cancer Cells
[0053] Animal models Two human lung cancer comprising NCI-H1975 (adenocarcinoma) and L78 (squmous carcinoma) and three other cells comprising MCF7 (breast carcinoma), HT-29 (colon carcinoma) and HepG2 (hepatocelluar carcinoma) were used in the study. These cell lines were maintained in RPMI 1640 (GIBCO, Mississauga, Canada) supplemented with 10% heat-inactivated calf serum and L-glutamine in an incubator at 37° C. with 5% CO 2 . Cells were harvested with trypsin/EDTA, washed with PAS twice and re-suspended in free serum culture medium at a concentration of 5×10 6 cells/mL. The suspended cells (0.2 mL) were inoculated s.c. into the back of nude mice to establish the cancer models, respectively. There are four nude mice in each group of cancer model. Tumor growth and general states such as mental, diet and weight were monitored periodically. When tumors reached approximately 1 cm in mean diameter, the tumor bearing mice were used in imaging and biodistribution studies.
[0054] Imaging of Molecular Probe in Cancer Models
[0055] Each tumor-bearing mouse was injected with 0.1 mL (2.96 MBq) of molecular probe via a tail vein respectively and scanned by SPECT. 99m Tc labeled non-related small peptides cNAQAEQc was used as a negative control for molecular probe. To monitor the distribution of molecular probe in vivo, images were acquired immediately and at 0.5 h, 1 h, 2 h, 3 h, 5 h, 6 h and 24 h after injection of molecular probe. Imaging at first time point and peak uptake time was also recorded. All these data were used to evaluate the imaging features of molecular probe in lung cancer and other cancer.
[0056] SPECT imaging of animals injected with molecular probe demonstrated major distribution to the kidneys and bladder and, to a lesser extent, to the liver. Low radioactivity was also observed in the intestine, limbs, head and chest. The increased intense radiotracer activity in bladder was shown while decreased uptake in the tumor (L78). Tumor imaging was vaguely at 30 min after the injection of molecular probe. With the tumor uptake gradually increasing, the image became clear visualization ( FIG. 10 ). FIG. 11 showed that the tumor (H1975) was clearly visualized at 2 h after injection of molecular probe, while the tumor image was blurry after injection of the control probe.
[0057] Biodistribution of Molecular Probe ( 99m Tc-cNGEGQQc) in Bearing Tumor Mice
[0058] The maximum tumor-specific accumulation occurred at 2 h after injection of molecular probe, while the highest kidney uptake and lowest brain uptake were observed postinjection. The target/non-target (T/NT) ratios were presented in Table 4, molecular probe had the higher tumor-to-brain (10.32) and tumor-to-muscle (4.76) ratios and lower tumor-to-blood ratio (1.46).
[0000]
TABLE 4
T/NT ratio of 99m Tc-cNGEGQQc in
mice bearing lung cancer (n = 3)
Tumor/organ
T/NT ratio
Tumor/liver
0.47 ± 0.13
Tumor/brain
10.32 ± 4.26
Tumor/kidney
0.23 ± 0.18
Tumor/lung
0.92 ± 0.17
Tumor/heart
4.43 ± 0.75
Tumor/bone
1.82 ± 0.84
Tumor/muscle
4.76 ± 0.79
Tumor/stomach
1.19 ± 0.11
Tumor/small intestine
1.11 ± 0.32
Tumor/blood
1.46 ± 0.26
[0059] As stated above, the tumor lesions (adenocarcinoma and squamous carcinoma of lung cancer) were clearly visualized after injection of molecular probe. However similar results were not achieved in breast cancer, colon cancer and hepatocellular carcinoma models. Meanwhile, no visual imaging was shown after injection of control probe. These data suggest that the peptide of our invention can be used as a pharmaceutically targeted carrier for delivery of imaging agent 99m Tc to NSCLC through the blood circulation, and specifically bind to lung cancer cells.
Example 6
Preparation of Radiotherapeutic Agent 131 I-cNGEGQQc for Lung Cancer
[0060] According to the procedure in example 2, cNGEGQQc-Tyr complex was synthesized by condensation reaction between the N-terminal of peptide prepared above and C-terminal of tyrosine with EDC-HCl (1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride amine) ( FIG. 12 ). The molar ratios in reaction mixture were 1:3:3.6. The reaction time was 2 hours at room temperature.
[0061] For labeling the peptide-Tyr complex with iodine-131 using the chloramine-T method (Yu M, et al. Ann Nucl Med. 2010; 24: 13-9), the procedure was performed according to the following manner Peptide-Tyr complex (50 μg) was dissolved in 50 μl of PBS buffer (0.5M, pH=6.8), then was added to 20 μl of 131 I (37 MBq), followed by 30 μl of chloramine-T (3 μg/μl) (final concentration 0.9 μg/μl). The component was mixed by a shaker for 2 min and the reaction was terminated by adding 45 μl of sodium thiosulfate (4 μg/μl). The reaction mixture was finally added 200 μl of PBS buffer (0.5M, pH=7.4). The peptides were determined by paper chromatography. A drop of the labeled peptides were placed on the paper, then dipped into a mixture liquid with n-butanol:ethanol:ammonia (5:1:2). Labeling efficiency of the labeled peptides was measured using radioactive thin-layer scanner. The labeled peptides were purified using gel filtration on Sephadex G-25 column. The radiochemical purity of purified peptides was measured using paper chromatography ( FIG. 13 ).
[0062] The preparation and purification of labeled peptide by Sephadex G25 were as follow: 1 g of Sephadex (dextran gel) 25 were soaked in PBS (pH=7.4) for 24 h. The fine particles were removed by gently shaking. After the Sephadex G25 was completely hydrated, pumping decompression was used to remove the air bubbles. Sephadex G25 was then added into a glass chromatography tube. PBS (pH=7.4) and BSA (20 mg dissolved in 1 mL of PBS) were added into the tube separately. After washing with PBS (pH=7.4), the reaction solution was filtered through the column. The eluate was monitored by absorbance at 280 nm and added appropriate amount of BSA and NaN 3 , followed by lyophilizing and aliquoting for future use.
Example 7
Labeling Efficiency and Stability of Radiotherapeutic Agent ( 131 I-cNGEGQQc) in Vitro
[0063] Labeling efficiency of molecular probe was determined by paper chromatography. The details were as follow: A drop of the molecular probe was placed on one side of the paper, then dipped into a mixture liquid with n-butanol:ethanol:ammonia (5:1:2). The separation occurs as the liquid moves along the paper. Take the paper out and dry it when the liquid moves to the other side of paper. Paper was cut into ten equal pieces and put into the tube separately. The radioactivity of each pieces of paper was measured by radioactivity counter and calculated labeling rate (radioactivity peaks of unpurified labeled peptide/sum of each radioactivity peak×100%) and radiochemical purity (radioactivity peaks of purified labeled peptide/sum of each radioactivity peak×100%). Rf of 131 I-labeled peptide was 0-0.1 and Rf of free 131 I was 0.4-0.6 and 0.9-1.0. The optimal conditions for labeling cNGEGQQc with 131 I were as follows: The best peptides/chloramine-T weight ratio was 1:1.8. Reaction conditions were at pH 7.4 and 20° C. for 2 min. The labeling rate of peptides using 131 I in the optimal conditions was over 90%. FIG. 14 present HPLC radiochromatograms of 131 I-labeled peptide.
[0064] To evaluate the stability of radiotherapeutic agent at room temperature and in fresh human serum for 24 h, radiochemical purity was measured using paper chromatography. After purification with HPLC, the radiochemical purity of 131 I-labeled cNGEGQQc was >90% at room temperature for 24 h. The stability of 131 I-labeled cNGEGQQc was further estimated in fresh human serum at 37° C. for 24 h. After 24 h incubation, 85% of 131 I-labeled cNGEGQQc remained intact in serum. The radiochemical purity was 92.5% at 0 h and 88.2% at 24 h respectively. These data suggests that 131 I-labeled cNGEGQQc is very stable in vitro and satisfactory to support biological evaluation in vivo.
Example 8
Biodistribution of Radiotherapeutic Agent ( 131 I-cNGEGQQc) in Mice
[0065] Fifteen normal Kunming male mice (4-6 weeks old, weight 19-21 g) were injected with 50 μl (0.48 MBq) of 131 I-labeled cNGEGQQc via a tail vein respectively. At 1, 3, 6, 12, and 24 h, three animals were anesthetized and sacrificed by cervical dislocation. Whole blood was collected and organs of interest were removed and weighed. The amount of radioactivity in blood and each organ was determined and calculate the percentage of the injected dose per gram of tissue (% ID/g). Subsequently,
[0066] SPECT (Millennium VG; GE Healthcare) was equipped with a low-energy, high resolution collimator. Images were acquired using energy peak centered at 364 KeV, an energy window of 20% and a 128×128 matrix at a magnification of 1.0.
[0067] The biodistribution 131 I-labeled cNGEGQQc in mice was summary in Table 5. SPECT imaging showed that the kidney had the highest radioactivity levels and longer clearance among all organs in healthy mice, indicating predominant renal excretion of 131 I-labeled cNGEGQQc. During the observation period, the radioactivity level in various organs gradually decreased, while the radioactivity of gastrointestinal was relatively stable. It indicated that the stability of 131 I-labeled cNGEGQQc was excellent and no free 131 I release in vivo. The least uptake of 131 I-labeled cNGEGQQc was observed in muscles and brain.
[0000]
TABLE 5
Biodistribution 131 1-labeled cNGEGQQc in mice (% ID/g)
Tissues
1 h
3 h
6 h
12 h
24 h
liver
0.3830 ± 0.0018
0.4152 ± 0.0024
0.1403 ± 0.0004
0.0829 ± 0.0007
0.0338 ± 0.0001
spleen
0.2034 ± 0.0008
0.3137 ± 0.0023
0.1841 ± 0.0002
0.0770 ± 0.0005
0.0384 ± 0.0001
kidney
2.4804 ± 0.0059
2.0763 ± 0.0072
0.9813 ± 0.0025
0.3812 ± 0.0023
0.2028 ± 0.0006
lung
0.3773 ± 0.0012
0.3896 ± 0.0021
0.2395 ± 0.0008
0.2879 ± 0.0023
0.0765 ± 0.0001
stomach
0.6943 ± 0.0034
1.2331 ± 0.0095
0.8734 ± 0.0035
0.7219 ± 0.0105
0.0696 ± 0.0005
intestine
0.2910 ± 0.0011
0.3185 ± 0.0012
0.1956 ± 0.0004
0.1354 ± 0.0009
0.0723 ± 0.0003
muscle
0.0800 ± 0.0002
0.0874 ± 0.0005
0.0515 ± 0.0004
0.0394 ± 0.0003
0.0206 ± 0.0001
bone
0.2420 ± 0.0005
0.2517 ± 0.0009
0.1604 ± 0.0006
0.0887 ± 0.0004
0.0702 ± 0.0001
brain
0.0279 ± 0.0007
0.0273 ± 0.0002
0.0159 ± 0.0004
0.0183 ± 0.0001
0.0170 ± 0.0001
blood
0.4297 ± 0.0019
0.5124 ± 0.0028
0.3971 ± 0.0016
0.1788 ± 0.0017
0.0644 ± 0.0002
[0068] Biodistribution of Radiotherapeutic Agent ( 131 I-cNGEGQQc) in Rabbits
[0069] Two of healthy Japanese male white rabbits were fixed in supine position on a wooden experimental stage. We set SPECT collimator on the rabbit thoracic and abdominal to ensure that the whole body of rabbit was within vision field of SPECT imaging. The injectant of 131 I-labeled cNGEGQQc dilution with saline water (0.5 mL/14.8 MBq) was administered through the ear vein injection. The images were obtained in two ways in order to evaluate and compare dynamic imaging with multitemporal static imaging. First, the images were acquired immediately at a rate of 1 frame/10 sec×6 after injection of the 131 I-cNGEGQQc, followed by a rate of 1 frame/1 min×4 and 1 frame/5 min×5. Second, multitemporal static images of anterior and posterior were obtained following the dynamic imaging at 0.5 h, 1 h and 3.5 h after injection. The posterior dynamic images were analyzed by ROI semi-quantitatively. The time-radioactivity curves of main organs comprising precordia, liver, spleen, kidney and bladder were obtained respectively by ROI analysis ( FIGS. 15-16 ).
Example 9
Inhibition of Lung Cancer Cell Growth by Radiotherapeutic Agent ( 131 I-cNGEGQQc) in Mice
[0070] Animal models. Two human lung cancer cell lines comprising NCI-H1975 (adenocarcinoma) and L78 (squmous carcinoma) were maintained in RPMI 1640 (GIBCO, Mississauga, Canada) supplemented with 10% heat-inactivated calf serum (HyClone, Logan, Utah) and L-glutamine (Beyotime, Jiangsu, China) in an incubator at 37° C. with 5% CO 2 . Cells were harvested with trypsin/EDTA, washed with PAS twice and re-suspended in free serum culture medium at a concentration of 5×10 6 cells/mL. The suspended cells (0.2 mL) were inoculated s.c. into the back of nude mice to establish the lung cancer models, respectively. There are twelve nude mice in each group of cancer model. Tumor growth and general states such as mental, diet and weight were monitored periodically. When tumors reached approximately 1 cm in mean diameter, the tumor bearing mice were used in therapeutic efficacy studies.
[0071] All mice received a solution of 0.2% potassium iodine orally to block uptake of free iodine-131 by the thyroid beginning from 3 days before treatment and to end of experiment. Twelve tumor bearing mice of each lung cancer cell line were randomly divided into four groups with three animals each and injected with 131 I-cNGEGQQc, 131 1-cNAQAEQc (negative peptide control), 131 I and normal saline via a tail vein, respectively. The tumor size was measured two dimensionally on days 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 after injection, while mice weight was also determined. The tumor volume was calculated by the formula volume V=(4/3)×π×R1×R2, where R1 is radius 1 and R2 is radius 2 and R1<R2. Growth curves of the tumors were constructed according to these tumor volumes.
[0072] The tumor size of H1975 and L78 in 131 I-cNGEGQQc treated groups decreased on days 7 after injection, while tumor grew continentally in the control groups ( FIGS. 17-18 ). The median survival time of each group was as follows: 54 days in mice with 131 I-cNGEGQQc; 45 days in mice with 131 I-cNAQAEQc; 42 days in mice with 131 I and 43 days in mice with normal saline. These results suggested that radiotherapeutic agent of the invention can significantly inhibit lung cancer growth in vivo.
Example 10
Evaluation of Toxicity of Radiotherapeutic Agent ( 131 I-cNGEGQQc) to Major Organs
[0073] 1) Analysis of Toxicity of Radiotherapeutic Agent in Mice Bearing Lung Cancer Cells
[0074] After treatment with radiotherapeutic agent for three weeks, the mice were sacrificed and the major tissues or organs such as blood, liver, kidneys, heart, lungs and spleen were removed completely. A routine blood test was performed using an automatic hematology analyzer to measure the following parameters: white blood cell (WBC), red blood cell (RBC) and platelet (PLT) count. Clinical biochemicals parameters measured with an automated biochemical analyzer were aspartate transferase (AST), alanine transferase (ALT), blood urea nitrogen (BUN) and creatinine (CRE). Histopathological and ultrastructural observations were performed on the preserved organs and tissues stated above.
[0075] The hematological analysis showed no significant changes of RBC, WBC and PLT in the radiotherapeutic agent treatment groups compared to the normal saline groups. The leukocyte count showed decrease between the control and 131 I-cNAQAEQc or 131 I groups. The data from the serum biochemical examinations demonstrated that there were no statistically significant differences of AST, ALT, BUN and CRE in either the control or treated group (P<0.05) (Table 6). The organs comprising liver, kidneys, heart and lungs were carefully examined. No histopathological and ultrastructural changes were observed in the organs of the control or treated group.
[0076] 2) Analysis of Toxicity of Radiotherapeutic Agent in Normal Rabbits
[0000]
TABLE 6
Effect of 131I-cNGEGQQc on blood cell and liver and
kidney function in mice bearing lung cancer (24 h)
Hematological analysis
Groups
RBC(T/L)
WBC(G/L)
PLT(G/L)
131 I-cNGEGQQc
8.1 ± 0.4
16.5 ± 0.5
1024.7 ± 39.0
131 I-cNAQAEQc
7.8 ± 0.3
14.4 ± 1.5*
974.7 ± 31.2
131 I
7.8 ± 0.2
13.6 ± 0.7*
991.2 ± 52.5
Normal saline
8.4 ± 0.5
17.8 ± 1.2
1143.8 ± 33.9
P value
>0.05
>0.05
>0.05
Biochemicals analysis
BUN
CRE
Groups
ALT(U/L)
AST(U/L)
(mmol/L)
(μmol/L)
131 I-cNGEGQQc
59.3 ± 4.8
173.6 ± 2.8
9.3 ± 0.6
33.4 ± 3.0
131 I-cNAQAEQc
62.6 ± 4.8
181.5 ± 5.1
9.8 ± 1.4
39.2 ± 2.5
131 I
60.7 ± 7.8
171.7 ± 0.8
9.4 ± 1.3
42.7 ± 3.8
Normal saline
66.0 ± 4.7
150.0 ± 2.7
8.2 ± 0.7
41.0 ± 3.3
P value
>0.05
>0.05
>0.05
>0.05
[0077] In relation to the hematological parameters, similar data were observed for the values of the control group; the effects were considered to be of no toxicological significance (p>0.05).
[0078] Six healthy rabbit were randomly divided into two groups with three animals each and injected with 131 I-cNGEGQQc and normal saline via a tail vein, respectively. Body temperature of each rabbit was measured at 15 min before injection and at 1 h, 12 h and 24 h after injection. The temperature range of each rabbit at different time point was as follow: 38.9-39.3° C. before injection; 38.7-39.2° C. at 1 h after injection; 39.1-39.6° C. at 12 h after injection; 38.9-39.1° C. at 24 h after injection. The largest temperature variance of each animal was below 0.7° C. during 24 h and below 1.5° C. in three tests. The blood samples were drawn from the ear vein of the rabbits for testing the count of blood cell (comprising RBC, WBC and PLT) and liver function (AST and ALT) and kidney function (CRE and BUN). The hematological analysis, liver and kidney function at three time-points were listed in Table 7. Based on the analysis results of the above-mentioned parameters, no significant differences were found between the treatment and the control group (P<0.05), except for a decrease of PLT at 24 h after treatment. No significant differences were also found in respiratory, autonomic and central nervous system and behavior pattern. These observations clearly suggest there is no toxicity of 131 I-cNGEGQQc to major organs comprising lungs, liver, kidneys and heart.
[0000]
TABLE 7
Effect of 131 I-cNGEGQQc on blood cell
and liver and kidney function
Hematological analysis
Groups
RBC(T/L)
WBC(G/L)
PLT(G/L)
Before treatment
4.8 ± 0.3
11.3 ± 0.5
343.7 ± 5.2
After
5.4 ± 0.5
9.6 ± 0.3
222.7 ± 5.3*
treatment(24 h)
After
5.2 ± 0.2
12.7 ± 1.7
320.7 ± 49.6
treatment(3 m)
P value
>0.05
>0.05
<0.05
Biochemicals analysis
BUN
CRE
Groups
ALT(U/L)
AST(U/L)
(mmol/L)
(μmol/L)
Before treatment
48.7 ± 1.8
14.3 ± 2.9
6.0 ± 0.5
89.3 ± 4.3
After
60.5 ± 10.3
22.1 ± 6.8
8.6 ± 0.3
97.7 ± 4.9
treatment(24 h)
After
49.4 ± 3.9
22.6 ± 6.3
9.9 ± 5.6
101.3 ± 8.4
treatment(3 m)
P value
>0.05
>0.05
>0.05
>0.05
[0079] The examples described above are preferred embodiments of the present invention. For the skilled person in the field, any apparent changes in the invention without departing from the spirit and scope for improvement should be considered part of the present invention. | A peptide including 8 animo acids having a sequence of cNGEGQQc, where c represents d-cysteine (Cys), N represents L-Asparagine (Asn), G represents L-Glycine (Gly), E represents L-Glutamic acid (Glu), and Q represents L-Glutamine (Gln). | 0 |
BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates, generally, to the construction arts. More particularly, it relates to an apparatus and method for making a sloped floor such as a shower floor.
2. Description of the Prior Art
U.S. Pat. Nos. 6,088,984 and 6,155,015 to the present inventor represent the prior art most relevant to the present invention. Those patents disclose apparatus and methods, respectively, for making a sloped floor, such as a shower floor, by positioning a plurality of elongate arms in radial array about a center ring that circumscribes a shower drain. Each arm has a flat bottom edge that rests atop a pitched or unpitched floor surface. Each arm has a sloped upper edge that determines the slope of the shower floor when the installation is completed. The height of each arm is relatively low at its radially innermost end where it connects to the center ring and is relatively higher at its radially outermost end where it abuts the vertical walls of the shower stall. Thus, when concrete is poured into the shower stall and screed so that it is flush with the uppermost edges of the arms, the resulting slope is predetermined by the arms. This eliminates the need to form the slope by more involved methods and enables an unlimited number of shower floors to be constructed with a common ideal slope.
The earlier system works well and has no substantial shortcomings.
Accordingly, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how further innovations could be provided.
SUMMARY OF INVENTION
The new, useful, and nonobvious invention of this disclosure enables the construction of a sloped floor with elongate arms that have a common height throughout their extent. The radially innermost end of each elongate arm may be attached to any part of a drain structure or to a center ring that circumscribes a drain. In a first embodiment, the slope of each elongate arm is adjustable by turning a setscrew positioned near a radially innermost end of the arm. In a second embodiment, a clip having a predetermined angular orientation is secured to a center ring and the radially innermost end of each arm is secured to the clip. The clip holds the arm so that the radially outermost end of the arm is elevated with respect to its radially innermost end, with the angle of slope being determined by the structure of the clip. In a third embodiment, each arm has a shallow construction so that it is removable from the cement after the floor has been poured. In a fourth embodiment, the radially outermost ends of the arms are secured to a fastening means that circumscribes the shower stall.
A primary object of the invention is to provide a method and apparatus for facilitating the installation of a sloped floor such as a shower floor.
Another closely related object is to enable such installation using elongate arms of uniform height.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a top plan view of a shower floor depicting the elongate arms having their respective radially innermost ends connected to a center ring that circumscribes a drain;
FIG. 2 is a top plan view of a first embodiment of a center ring;
FIG. 3 is a perspective view of the center ring depicted in FIG. 2;
FIG. 4 is a top plan view of a second embodiment of the center ring;
FIG. 5 is a perspective view of the center ring depicted in FIG. 4;
FIG. 6 is a side elevational view of a first embodiment of an elongate arm of uniform height along its extent;
FIG. 7 is a top plan view of the arm depicted in FIG. 6;
FIG. 8 is a side elevational view of a means for pivotally interconnecting an elongate arm to the center ring;
FIG. 9 is a top plan view of the means of FIG. 8;
FIG. 10 is a front end view of the means of FIG. 8;
FIG. 11 is a perspective view of the means of FIG. 8;
FIG. 12 is a side elevational view of the arm of FIGS. 6 and 7 disposed in interconnected relation to the means of FIGS. 8-11 when said arm is in a horizontal disposition;
FIG. 13 is a side elevational view of the arm of FIGS. 6 and 7 disposed in interconnected relation to the means of FIGS. 8-11 when said arm is in a sloped disposition;
FIG. 14 is a side elevational view of a second embodiment of the elongate arm;
FIG. 15 is a top plan view of the arm depicted in FIG. 14;
FIG. 16 is a top plan view of a means for interconnecting the radially innermost end of an elongate arm to the center ring of FIGS. 4 and 5;
FIG. 17 is a front end view of the means depicted in FIG. 16;
FIG. 18 is a side elevational view of the means depicted in FIG. 16;
FIG. 19 is a perspective view of the means depicted in FIGS. 16-18;
FIG. 20 is a perspective view of a third embodiment of the elongate arm;
FIG. 21 is a perspective view of a telescopically constructed version of the elongate arm of FIG. 20;
FIG. 22 is a side elevational view depicting the elongate arm of FIGS. 20 or 21 adapted for pivotal connection to the connector of FIGS. 8-11;
FIG. 23 is a plan view of an embodiment of the elongate arm having a bulbous radially innermost end;
FIG. 24 is a side elevational view depicting an alternative means for elevating a radially outward end of an elongate arm;
FIG. 25 is a top plan view of a third embodiment of the center ring; and
FIG. 26 is a side elevational view of an elongate arm adapted to engage the center ring of FIG. 25 .
DETAILED DESCRIPTION
Referring to FIG. 1, it will there be seen that the reference numeral 10 denotes an illustrative embodiment of the present invention installed in a shower stall 12 or other room having a floor 14 that slopes to a drain 16 .
A plurality of arms 18 of elongate construction is depicted in radial array relative to drain 16 . The radially innermost end of each arm 18 is positioned contiguous to drain 16 but need not be attached thereto. However, unwanted movement of said arms can be prevented by securing the radially innermost ends to a part of the drain. For example, said radially innermost ends may be secured to the body of the drain, the frame, the riser, the strainer, or any other related part of the drain.
In the preferred embodiment of this invention, the radially innermost ends are secured to center ring 20 . Said center ring 20 is positioned in circumscribing relation to drain 16 , preferably in concentric relation therewith.
FIG. 2 depicts center ring 20 in plan view and FIG. 3 provides a perspective view thereof. A plurality of blind cylindrical bores, collectively denoted 22 , is formed in center ring 20 in circumferentially and equidistantly spaced relation to one another. Each blind bore has a radially outermost section in open communication with the outer peripheral edge of center ring 20 as perhaps best understood in connection with FIG. 3 .
An alternative embodiment 20 a of center ring 20 is depicted in FIGS. 4 and 5. The blind bores 22 a of this embodiment are also circumferentially and equidistantly spaced apart from one another, but instead of having a cylindrical cross-section, their respective cross-sections have a generally “T”-shaped configuration. The base of each bore is in open communication with the outer peripheral edge of center ring 20 a.
A side elevational view of an arm 18 is provided in FIG. 6 . In this embodiment, an unnumbered truss-like structure provides the needed strength while saving materials and reducing the weight of the arm. The upper edge of arm 18 is denoted 19 . When concrete is poured to complete the sloped floor, it is made flush with upper edge 19 . Thus, the rest of arm 18 is permanently embedded in the concrete.
As perhaps best understood in connection with FIG. 7, a transversely disposed peg or pivot pin 24 is formed in the leading end of arm 18 . As best indicated in FIG. 6, beveled surface 26 is formed in said arm just to the rear of said pivot pin. Cylindrical throughbore 28 has a lowermost or leading end in open communication with beveled surface 26 and the longitudinal axis of the throughbore is perpendicular to said beveled surface 26 .
It should also be noted at the right hand end of FIGS. 6 and 7 that the trailing end of arm 18 is adapted to engage the leading end of an auxiliary arm 18 a (FIG. 1) of similar construction to thereby effectively lengthen arm 18 in those applications requiring arms of greater extent. FIG. 1 depicts auxiliary arms 18 a having their respective leading ends releasably engaged to the respective trailing ends of arms 18 .
Connector 30 , depicted in FIGS. 8-11, interconnects the leading or radially innermost end of an arm 18 to center ring 20 . There is a plurality of said connectors connected to center ring 20 in circumferentially spaced relation to one another. Each connector 30 has a radially innermost part 32 that fully occupies an associated blind bore 22 of center ring 20 when the novel apparatus is assembled. The cylindrical cross-section of said part 32 is depicted in the plan view of FIG. 9 . The opposite ends of pivot pin 24 (FIGS. 6 and 7) are pivotally supported in the respective rounded bottoms 32 a , 32 b of vertical slots 34 a , 34 b , formed in upstanding sidewalls 36 a , 36 b of connector 30 when the leading (radially innermost) end of arm 18 is positioned in sandwiched relation between said upstanding sidewalls 36 a , 36 b.
An imperforate bearing wall 38 interconnects sidewalls 36 a , 36 b , as perhaps best understood in connection with FIGS. 9 and 11.
As best understood in connection with FIGS. 12 and 13, beveled surface 26 (FIG. 6) of arm 18 overlies bearing wall 38 when arm 18 is in repose. Note that an unnumbered gap exists between beveled surfaces 40 a , 40 b and beveled surface 26 when said arm 18 is in repose. The slopes of the mating beveled surfaces are preselected so that arm 18 is sloped toward the center ring or drain at a quarter inch per foot when said arm is in said position of repose. Accordingly, if concrete were poured into the shower area and screed to the level of upper edge 19 , the resulting floor would have a quarter inch per foot slope. However, there is no requirement that this minimum slope be built in. It is also within the scope of this invention to form the mating beveled surfaces so that arm 18 is horizontal when in repose. The user would then be required to slope the arm in the manner hereinafter to be described. Even if a quarter inch slope is built in, the following steps are required to increase the slope if desired.
To impart additional slope to arm 18 and hence to upper edge 19 thereof, setscrew 29 is advanced in setscrew bore 28 so that its leading end bears against bearing wall 38 . The unnumbered gap appearing in FIG. 12 decreases in size and disappears as setscrew 29 is advanced further and further until said setscrew is fully advanced as depicted in FIG. 13 . Simultaneously, an unnumbered gap appears between beveled surface 26 of arm 18 and bearing surface 38 of connector 30 . The radially innermost end of arm 18 is now disposed between upstanding beveled surfaces 40 a , 40 b formed in sidewalls 36 a , 36 b . This imparts a maximum slope to arm 18 and hence upper edge 19 thereof. Thus, any intermediate degree of slope is attained by advancing the setscrew an appropriate distance between its unadvanced and fully advanced positions, there being an infinite plurality of functional positions of adjustment between the in-repose position of FIG. 12 and the fully inclined position of FIG. 13 .
An optional auxiliary screw 17 is screw threadedly, slidingly, or otherwise adjustably engaged in a bore formed in a radially outermost end of arm 18 as depicted in FIG. 13 . However, screw 17 could also be positioned radially inwardly relative to said radially outermost end and still perform the same function. Screw 17 supports said radially outermost end, but it may be eliminated from the novel apparatus without significant detriment to the system.
A second embodiment of elongate arm 18 , denoted 18 a in FIGS. 14 and 15, is adapted at its radially innermost end to engage connector 42 of FIGS. 16-19. Specifically, a “T”-shaped connector 21 is formed in said radially innermost end. Connector 42 has a “T”-shaped radially innermost part 44 that engages an associated “T”-shaped bore 22 a formed in center ring 20 a of FIGS. 4 and 5. Connector 42 further includes a “T”-shaped bore 46 formed in its radially outermost end. Bore 46 slidingly receives “T”-shaped connector 21 formed in the radially innermost end of arm 18 a . Significantly, a slope is imparted to arm 18 a because bore 46 is canted relative to a vertical plane at a predetermined angle that is hard to see in the Figure but which should be understood as being present.
Rod 50 of FIG. 20 has a triangular cross-section. It may be formed of aluminum, stainless steel, plastic, metal-containing plastic, or other suitably stiff and durable material.
As indicated in FIG. 21, rod 50 a may have a telescopic construction. Thus, in an application where rod 50 has insufficient length, rod 50 a is advantageously used. The user merely extends rod 50 a to the desired extent and tightens setscrews 51 to maintain the proper length when said proper length has been found.
Unlike arms 18 and 18 a , rod 50 or 50 a has a very shallow construction. In a preferred embodiment, the uniform height of rod 50 or 50 a is about one-quarter inch. Thus, when concrete is poured and worked until it is flush with the flat top wall of arm 50 or 50 a , it is easy to retrieve said arm so that it is not embedded in the floor. A shallow “V”-shaped groove remains in the floor, but such groove is filled if needed and covered by tile when the installation is complete.
The radially innermost end of rod 50 or 50 a , like arms 18 and 18 a , may be attached to a center ring such as center ring 20 , for example, or it may be attacked to a preselected part of drain 16 , or it may be positioned near said drain but not attached thereto.
As indicated in FIG. 22, rod 50 or 50 a may be connected to center ring 20 by the same coupler 30 depicted in FIGS. 8-11. Alternatively, many different types of couplers could be used to pivotally attach the radially innermost end of rod 50 or 50 a to said center ring.
However, the desired pivotal connection may also be made in the absence of a coupler because the radially innermost end of rod 50 or 50 a could be directly pivotally coupled to said center ring. For example, a bulbous means 53 is formed on the radially innermost end of a rod 50 or 50 a as depicted in FIG. 23 . Bulbous means 53 forms a ball suitable for connection to a socket of the type formed in center ring 20 of FIGS. 2 and 3. Numerous ways could then be provided to impart a slope as desired to such rod. Any height-adjustment means, such as but not limited to screw 17 of FIG. 13, could be employed, for example. A ratchet and pawl mechanism could be provided as well, as a part of the ball and socket interconnection, so that the slope could be adjusted simply by lifting the radially outermost end of the rod. An adjustable height means could be employed in conjunction with such a ratchet and pawl arrangement.
The radially outermost end of arm 18 , 18 a , or rod 50 , 50 a may also be advantageously secured to a mounting means secured to the shower wall that is elevated with respect to the drain by a predetermined amount. As depicted in FIG. 24, mounting means 52 is preferably provided in the form of a bracket or strip of material that is mountable by suitable means to shower walls 12 a , 12 b , 12 c , and 12 d (FIG. 1 ). It may have a channel or “J” shape as depicted, or any other functional shape. Thus, the radially outermost end of an arm 18 , 18 a , or rod 50 , 50 a is easily secured to said strip 52 and the desired slope is thereby established. The installer must position bracket 52 at a proper elevation relative to shower floor 14 to achieve the desired angle of slope.
In the alternative, the radially outermost end of arms 18 , 18 a , or rods 50 , 50 a , may be supported by adjustable height means such as screw 17 in FIG. 13 or mounting strip 52 in FIG. 24 . Said radially outermost ends may also be unsupported. In such event, the arm or rod is supported at a preselected slope by the means for coupling the arm or rod to the center ring or the drain.
Neither arms 18 , 18 a , nor rod 50 , 50 a has the tapered construction of the arms of the prior art. Such arms and rods are thus easier and less expensive to manufacture than the tapered arms. Moreover, the means disclosed herein for positioning said arms and rods at various predetermined angles to create sloped floors further advances the construction arts in a substantial way.
A circular slot 22 b is formed in center ring 20 b of FIG. 25 in substantially concentric relation therewith. Slot 22 b is slideably engageable by any of the elongate arms of this invention, not just elongate arm 50 as depicted. Any suitable engagement means such as elbow 53 a may be employed. Elbow 53 a may be hingedly mounted to an elongate arm so that the angle between said elongate arm and said elbow is adjustable to any degree of slope that may be required to complete a sloped floor in accordance with the teachings of this invention. As in the earlier-described embodiments, all other means for changing the angle between such elbow and the elongate arm are within the scope of this invention, including ratchet and pawl mechanisms, setscrews, couplers such as those depicted in FIGS. 16-19, means for holding the radially outermost end of the elongate arm at a predetermined elevation such as depicted in FIG. 24, and so on. Moreover, any attachment means that is slideably disposed within circular slot 22 b is within the scope of this invention, not just elbow 53 a.
Advantageously, circular slot 22 b enables elongate arms such as 18 , 18 a , 50 , 50 a to be positioned in infinitely many functional angles of radial adjustment relative to center ring 20 b . Moreover, the cementitious material used to complete the sloped floor cannot enter into slot 22 b ; note that such material can enter into openings 22 of center ring 20 and openings 22 a of center ring 22 because such openings are in open communication with the exterior surface of center rings 20 , 22 . Thus, if a center ring is re-used, openings 22 or 22 a must be cleaned out prior to re-use. No such cleaning is required when center ring 20 b is used.
It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.
Now that the invention has been described, | An apparatus and method for making a sloped floor includes a plurality of elongate arms disposed in radial array relative to a drain. Each arm has a common height along its extent. The radially innermost end of each arm is positioned near or connected to the drain. In a first embodiment, the radially innermost end of each arm is pivotally connected to an adapter that is connected to a center ring that circumscribes the drain. In a second embodiment, each arm is positioned at an incline by an adapter that rigidly joins the arm to the center ring. In a third embodiment, the arms are of shallow construction and are removed after the concrete has been poured. A mounting strip secured to the shower wall may support the radially outermost end of each arm. In all embodiments, the concrete is worked so that it is flush with the uppermost edge of each elongate arm. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to vision testing, for example testing to assess visual performance. Particularly preferred embodiments of the invention relate to a method for measuring visual sensitivity and to apparatus for implementing that method. By way of example, such testing can prove to be useful in assessing minimum vision requirements in specified occupational environments and for detecting changes in visual sensitivity caused by disease or for monitoring the outcome of treatment.
BACKGROUND TO THE INVENTION
[0002] A variety of occupational, visual tests have previously been proposed for the assessment of various aspects of visual performance. For example, colour vision screening has previously been used as a means for detecting colour deficiencies, and as a means for assessing the severity of a user's colour vision loss.
[0003] Colour vision testing has also been used to determine whether a user's vision meets the colour vision requirements for a given occupation (for example: aviation, fire, transport or police services); to assist in the detection of diseases (such as diabetes or multiple sclerosis, for example) that can affect visual performance; to assist in the diagnosis of specific diseases of the eye (e.g., optic neuritis, age related macular degeneration, photoreceptor dystrophies, etc); to facilitate disease management and treatment monitoring, and to enable the monitoring of eye-related side-effects in drug trials.
[0004] One illustrative vision test that has previously been proposed is described in a paper entitled “New test to assess pilot's vision following refractive surgery” by C. M. Chisholm, A. D. Evans, J. A. Harlow, and J. L. Barbur (published in: Aviation, Space and Environmental Medicine 2003 May; 74(5): pages 551-559). The test described in this paper assessed the quality of spatial vision by using a Contrast Acuity Assessment (CAA) test at normal levels of ambient light (i.e., photopic vision). In essence, this test assessed the quality of achromatic vision by measuring the smallest luminance contrast needed to resolve and locate the position of a gap in an annulus.
[0005] Another illustrative, classic vision test involves the measurement of high contrast Visual Acuity (VA). In this test, a user is asked to locate the orientation of the gap in a Landolt C optotype, and the user's visual acuity is assessed on the basis of the smallest, high contrast Landolt C for which the user can resolve and locate the orientation of the gap. The test is carried out with both bright and dark targets and the results provide a measure of visual acuity similar to that measured with Snellen letter charts in optometric practices, but with improved accuracy and the use of a single target. The test can also be used to assess the effect of “visual crowding” when the test target is surrounded by other targets.
[0006] Yet another illustrative vision test is described in a paper entitled “Insights into the different exploits of colour in the visual cortex” by J. L. Barbur, A. J. Harlow, and G. T. Plant. (published in Proc. R. Soc. Lond. B. Biol. Sci. 258 (1353):327-334, 19944). The test described in this paper used CAD (Colour Assessment & Diagnosis) to measure red-green and yellow-blue chromatic sensitivity. The paper also describes how background modulation techniques can be used to isolate the use of colour signals, a prime requirement in colour vision testing.
[0007] A further illustrative test (known generally in the art as an “advanced vision test”) is described in a paper entitled “‘Double-blindsight’ revealed through the processing of color and luminance contrast defined motion signals” by J. L. Barbur (published in: Progress in Brain Research, 2004, Volume 144, pages 243 to 259). This paper described a motion contrast sensitivity (MCS) test that involves the measurement of the smallest luminance contrast that a user needs to see motion and to discriminate correctly the direction of movement.
[0008] The foregoing tests are usually undertaken by displaying computer generated images to a subject via a very high quality and high definition monitor, typically a cathode ray tube. The subject attends to the images presented on the display and operates an input device, typically a selection of switches, in response to the stimuli they are observing on the screen. For example, in a test where the user might be required to identify the location of a gap in a Landolt C optotype, the input device may comprise four switches and the user may be instructed to operate the switch that corresponds to the quadrant of the image (top left, bottom left, top right or bottom right) in which the gap in the Landolt C optotype is located. Once the user has responded to the particular image being displayed, a new image is presented for the user to respond to, and this process continues until a range of images have been presented and corresponding user responses have been noted. The computer program then determines the user's visual performance based on their responses to the images displayed.
[0009] Whilst these systems have been shown to be effective in vision testing and have enabled subjects' visual performance to be accurately assessed, it is generally the case that the equipment (in particular the display) required to perform these tests is typically very expensive and hence tends only to be accessible at selected hospitals or research centres. As the equipment tends not to be universally provided, users can often live a relatively long way from the nearest hospital that has the facility to undertake these tests. Travelling to these hospitals is not too much of a problem for able-bodied users, but can be problematic for less able users who cannot travel so easily. The use of such tests for mass screening of diseases of the eye is therefore very limited.
[0010] It is also the case that in less developed regions of the world the cost of the equipment is such that the majority of hospitals simply do not have the funds available to acquire the equipment they would need to implement these tests. One unfortunate consequence of this is that many users continue to endure conditions that could perhaps be treated if their vision were to be properly investigated.
[0011] It would be highly advantageous, therefore, if a less expensive solution could be proposed, which solution would be more affordable and hence more accessible to users as it would be more likely to be implemented on a wider scale.
[0012] However, whilst an easier and less expensive implementation of such tests would undoubtedly be an improvement to existing arrangements, there will still be those users for whom travel is impossible and those hospitals that are still unable to afford the equipment.
[0013] Such problems could be mitigated if a testing system could be devised that utilised commonly available visual equipment (such as a computer monitor for example) for the display of tests to users, as users would then be able to undertake the tests using their own equipment and in their own homes. However, the problem here is that the tests are carefully designed to have particular visual characteristics, and it would be very difficult to ensure that reproduced tests still have those characteristics when the visual equipment used for the purpose is likely to differ widely from user to user.
[0014] The present invention has been conceived with the aim of addressing one or more of the aforementioned problems.
SUMMARY OF THE INVENTION
[0015] To this end, a presently preferred embodiment of the present invention provides advanced vision testing apparatus comprising: a display; means for determining the performance characteristics of said display; means for adapting a vision test in accordance with said determined performance characteristics so that the test is faithfully displayed on said display; means for displaying said adapted test to a user; and means for registering user input in response to said displayed test.
[0016] In a particularly preferred embodiment, the apparatus further comprises means for storing the subject's results. The apparatus may comprise one or more of the following: means for detecting any statistically significant changes (in a subject's results) over time; means for diagnosing systemic diseases or specific diseases of the eye from the pattern of results obtained from several vision tests.
[0017] Another embodiment of the invention relates to vision testing apparatus comprising: a local display; means for obtaining data characterising the performance characteristics of said local display; means for displaying to a user at said local display, a vision test that comprises an adaptation of a reference vision test; means for registering user input in response to said displayed vision test; and means for providing the user with the results of said displayed test; wherein said reference vision test comprises a test that is optimised for display on a high quality display, and the vision test for display at said local display is obtained by adapting said reference test in accordance with said characterising data so that the vision test displayed on said local display is a faithful reproduction of said reference test.
[0018] Preferably, the apparatus comprises a communications interface configured for transmitting information to and receiving information from a remote processing centre. The remote processing centre may comprise a store for reference vision tests.
[0019] The remote processing centre may comprise means for adapting reference vision tests in accordance with data characterising the performance characteristics of a remote display.
[0020] The adapting means may be configured to adapt a selected reference vision test in accordance with received data characterising the display of a remote vision testing apparatus to thereby generate an adapted vision test for viewing at said remote testing apparatus, and to send said adapted vision test to said remote vision testing apparatus for display.
[0021] Preferably, the testing apparatus is configured to send registered user input to said remote processing centre. The remote processing centre may comprise means for analysing registered user input received from said remote processing centre, and for generating results for transmittal to said remote testing apparatus and provision to said user.
[0022] The results may comprise a diagnosis that has automatically been generated based on the analysis of said registered user input. The remote processing centre may comprise a store for registered user input, and means for storing received registered user input pertaining to a completed test.
[0023] The remote processing centre may comprise means for analysing stored user input pertaining to a test that has been completed by a user on several occasions, and for identifying trends in said user input.
[0024] The vision testing apparatus may be configured to receive selected reference vision tests from said remote processing centre. The vision testing apparatus may comprise means for adapting reference vision tests in accordance with the data characterising the performance characteristics of the local display.
[0025] The adapting means may be configured to adapt a selected reference vision test in accordance with said characterising data to thereby generate the adapted vision test for viewing at said local display.
[0026] The testing apparatus may comprise means for analysing registered user input and for generating results for display to said user. The results may comprise a diagnosis that has automatically been generated based on the analysis of said registered user input. The testing apparatus may comprise means for sending registered user input to said remote processing centre, and wherein said remote processing centre comprises a store for registered user input, and means for storing registered user input pertaining to a completed test in said store. The remote processing centre may comprise means for analysing stored user input pertaining to a test that has been completed by a user on several occasions, and for identifying trends in said user input.
[0027] The testing apparatus may comprise means for retrieving, from said remote processing centre store, stored user input pertaining to a test that has been completed by a user on several occasions; and means for analysing said retrieved user input to identify and trends therein.
[0028] The adapting means may be configured to calculate, based on said characterising data, the luminances of red, green and blue display primaries that are required for the faithful display of the luminance and chromaticity triplets of said reference test. The adapting means may be configured to correct for back-scatter within said display.
[0029] In a particularly preferred arrangement, said communications network comprises an internet.
[0030] The means for registering user input may comprise one or more buttons each operable by a user to generate a signal. Preferably the means for registering use input comprises a housing having a front face and at least four buttons arranged generally in a square projecting therefrom.
[0031] The means for obtaining characterising data may include a plurality of photoreceptors. The photoreceptors may be provided within a housing that is adapted to be placed adjacent to a front face of said display, the photoreceptors being arranged in said housing to capture light from said front face. The housing may include a clip that is configured to locate on a portion of said display to properly locate said housing with respect to said display.
[0032] Another embodiment of the present invention relates to a method of testing vision, the method comprising: obtaining data characterising the performance characteristics of a local display; adapting a reference vision test in accordance with said characterising data to generate an adapted vision test that is a faithful reproduction of said reference test when displayed on said local display; displaying said adapted vision test to a user at said local display; registering user input in response to said displayed adapted vision test; generating a set of results based on said registered user input; and providing said results to the user.
[0033] Yet another embodiment of the present invention relates to a vision testing system comprising a vision test web-server and a local vision testing apparatus that can each communicate one with the other via an internet, wherein: the local vision testing apparatus comprises: a local display; means for obtaining data characterising the performance characteristics of said local display; means for displaying to a user at said local display, a vision test that comprises an adaptation of a reference vision test; means for registering user input in response to said displayed vision test; means for providing the user with the results of said displayed test; and a communications interface for web-based communications with said web-server; the vision test web-server comprises: a store for reference vision tests; means for adapting a selected vision test with data characterising the local display of said vision test apparatus; means for sending said adapted vision test to said local vision testing apparatus for display to a user; means for generating a set of results based on registered user input received from said local vision testing apparatus; and means for sending said results to said local vision testing apparatus.
[0034] Further preferred features are set out in the claims, and other aspects, aims, embodiments and advantages of the teachings of the invention are set out in the following detailed description and elsewhere in the present application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Various aspects of the teachings of the present invention, and arrangements embodying those teachings, will hereafter be described by way of illustrative example with reference to the accompanying drawings, in which:
[0036] FIG. 1 is a schematic representation of a system according to the present invention;
[0037] FIG. 2 is a schematic representation of a user response device;
[0038] FIG. 3 is a schematic representation of a display screen and installed calibration detector;
[0039] FIG. 4 is a schematic plot of display luminance versus drive signal;
[0040] FIG. 5 a is a schematic plot of scatter luminance versus disc radius, and FIG. 5 b is a schematic representation of three illustrative images used for determination of a plot of the type depicted in FIG. 5 a;
[0041] FIG. 6 is a schematic representation of the steps of a method of vision testing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] Referring now to FIG. 1 , there is shown an illustrative embodiment of the optometric system 1 according to a preferred embodiment of the present invention.
[0043] The system comprises a computing resource, such as a personal computer, that is configured as a test server 3 operable to generate vision tests for display to a user. The server is coupled to a data store 4 (comprising, for example, one or more hard disk drives) in which one or more reference visual tests are stored, each of those reference visual tests comprising a plurality of images that make up a given visual test, the images and the test as a whole being optimised for display on a high quality display with performance characteristics as close as possible to those of an ideal display.
[0044] The test server 3 is coupled by way of a communications network 5 to a second computing resource, such as a personal computer, that is configured as a user terminal 7 . The user terminal is coupled to a display device 9 (typically a non-ideal display device), such as a cathode ray tube (CRT) or LCD (liquid crystal display), and is configured to display test images received from the test server 3 to a user (not shown). The user terminal is connected to a user input device 11 for the input of user responses to displayed stimuli, and to a calibration detector 13 that is used (in a manner that will later be described) to determine the visual properties of the particular display device 9 that is coupled to the terminal 7 .
[0045] Information characterising the visual properties of the display is sent to the server 3 , and the test server 3 is configured to adapt the appropriate reference test images for display to the user in accordance with the received information so that the test images to be viewed by the user at the display device 9 have a chromaticity and luminance that causes the displayed test images to be a faithful reproduction of the images of the reference test.
[0046] The network 5 may comprise any one or more types of communication networks. In one arrangement the network may comprise a local or wide area network (LAN or WAN), and in another particularly preferred arrangement the network may comprise an internet such as the world wide web. This latter arrangement is particularly preferred as it raises the possibility of users in less developed countries being provided with access to leading diagnostic techniques commonly employed in more developed countries.
[0047] If the system is implemented via the world wide web, then the server 3 may comprise a webserver to which the client terminal can connect and run a test in a window in a web browser. In an alternative arrangement that is preferred where bandwidth may be limited, tests can be downloaded from the server for local execution and display at the user terminal.
[0048] Referring now to FIG. 2 , the user response device 11 comprises a housing 15 having a top surface 17 through which, in this instance, four buttons 19 project. The response device includes control circuitry that is operable to detect when the buttons are pressed by a user and generate a signal indicative of those button presses for transfer to the terminal 7 via the cable 21 . In this arrangement the buttons correspond to four regions of a test image display area—namely, a top left region, a bottom left region, a top right region and a bottom right region.
[0049] In use a subject may, for example, be shown an image of a Landolt C optotype and be asked to identify whether the gap is in the top left, bottom left, top right or bottom right quadrant of the display by pressing the corresponding button on the user response device. For most vision tests, four buttons will suffice, although five buttons (with the fifth button being located at the centre of the square formed by the other four buttons) may also be employed. Ultimately, the number of buttons provided will depend on the test, and as such it will be appreciated that a greater or lesser number of buttons may instead be provided if desired.
[0050] Referring now to FIG. 3 , there is shown a display device 9 (in this instance a CRT) that defines a viewing area 27 . As is known in the art, the screen of a CRT is made up of a number of discrete picture elements or pixels, and in the limiting case each pixel of a color display screen consists of three phosphors each driven by separate electron guns. Ideally, activation of one of these guns causes a single class of phosphor to emit light, and the luminance of a given pixel is defined in terms of three values (one for each electron gun) that are used to alter the voltage of the electron guns in the display, and hence the “colour” of that pixel.
[0051] In an ideal display pixel luminance would be linearly related to drive voltage. However, in practice (as illustrated in FIG. 4 ) the luminance of the red, green and blue primaries is a non-linear function of the drive signals applied, in this instance, to the red, green and blue electron guns within the CRT. In general, the degree of non-linearity increases as the quality of the display decreases.
[0052] A further problem is that the luminance of the display is non-uniform over the viewing area 27 . This is particularly the case, and becomes progressively more apparent, away from a generally central viewing region 25 towards the edge of the viewing area 27 .
[0053] These non-linearities and non-uniformities tend to have little effect on the image when the display is used for conventional purposes, but they can be of great significance when the display is used to display test images of the type described herein, as successive images may only be very slightly different from one another, and if the display is such that those differences cannot be determined by the viewer then the accuracy of the test will be adversely affected.
[0054] To investigate the performance of the display a detector assembly is provided to enable the output of the display to be measured. The detector assembly is plugged into the subject's terminal to enable the capture of data from it, and comprises a housing 29 within which a plurality of light detectors are provided, the detectors being orientated to capture light emitted by the display. The detector assembly further comprises a mounting arm 31 that is adapted to engage with the top of the monitor and sized so as to correctly locate the photometers in the central viewing region 25 of the display.
[0055] To reduce the impact of non-uniformities across the surface of the viewing area, the system of the present invention is configured so that test images are displayed only within the generally central viewing region 25 of the viewing area 27 (within which region the non-uniformities are lowest).
[0056] By configuring the display in this way, the impact of these surface non-uniformities can be reduced. However, the present inventors have found that the luminance of the relatively large remainder of the viewing area 27 (in which no test images are displayed) can have a direct effect on the luminance of images displayed within the central viewing region. Investigations have suggested that this variance in luminance may result from back-scatter of photons within the display, and to address this unwanted scattering the present inventors have devised a means for determining the extent to which a displayed test image will be affected by back scatter within the display. On some visual displays, the calibration curves that describe the relation between the light output of each gun at the centre of the display and the corresponding voltage drive signal vary systematically with the overall luminance of the whole background field, and if advanced vision tests are to be implemented on visual displays it is preferred for these potential artefacts to be accounted for.
[0057] Determination of back scatter is accomplished by displaying a series of images of the type shown in FIG. 5 b which comprise a dark central region 32 and a lighter background region 33 , and measuring the extent to which the luminance of the dark central region is affected as the size of the lighter background region is varied. FIG. 5 a is a plot of scattered light versus centre disk radius, and it is clear from this figure that as the radius of the central disk (in FIG. 5 b ) reduces so the scattered light increases and the luminance of the central darker region is increased. From this relationship it is possible to derive a calibration curve, shown in FIG. 5 c , indicating the relationship between background luminance and the luminance of the dark central region. Once this relationship has been established, the test image can be corrected for internal scatter within the display for a background that has the luminance of the background employed in the particular test being undertaken.
[0058] To reduce the impact of non-linearities in the relationship between drive voltage and luminance, the background surrounding the viewing region is set to have a luminance and chromaticity which is at least similar to that employed in the test that the user is to undertake, and the luminance is measured as each of the electron guns are driven through the entire voltage supply range to derive the Luminance versus Drive signal curves of the type shown in FIG. 4 . If the test to be undertaken should involve the display of backgrounds at different luminances, then this step of the calibration process is repeated to derive, for each luminance, a luminance versus drive signal curve for each of the electron guns.
[0059] In a next step the spectral radiance (i.e. the amount of light (or radiant flux) of a given wavelength per unit solid angle per unit area of the display that is emitted in a given direction) is measured for each display primary light for the purpose of calculating the chromaticity co-ordinates (x, y) of each primary. This is accomplished without a surround so as to ensure that the light emitted comes only from one primary. Chromaticity co-ordinates, as is known in the art, comprise two numbers that together specify the ratio of cone photoreceptor signals in the eye generated in response to light of given spectral composition.
[0060] The calibration data (i.e., the chromaticity co-ordinates and the luminance versus drive voltage curve for each primary) are then used in standard colorimetric equations (for examples of the equations, see G. W. Wyszecki and W. S. Stiles. “Color Science—Concepts and Methods, Quantitative Data and Formulae”, New York: John Wiley & Sons, 1982—the contents of which are incorporated herein in its entirety) to calculate the luminances of the red, green and blue primaries needed to reproduce any specified luminance, chromaticity triplet (i.e., L, x, y) within the limits imposed by the display device.
[0061] Once this procedure has been completed, it is then possible to produce visual stimuli on displays with the accurate control of luminance and chromaticity that is needed for the various tests of visual performance described herein.
[0062] Determination of the performance of the display is accomplished when the display is first registered for use in the system, and once the calibration data for that display have been determined they are stored on the server in association with a special identifier that identifies uniquely the particular display and computer combination at the user terminal. In a preferred arrangement, each time a given user terminal is used, a check is made as to whether a unique identifier retrieved from that terminal matches that stored at the server for this terminal. If the identifier retrieved from the terminal should be different to that stored at the server, then the terminal displays a message indicating that the terminal display must be calibrated before the test can continue. Recalibration is also recommended to the user depending on the date of the last recalibration.
[0063] In one envisaged implementation, described hereafter in connection with FIG. 6 , the teachings of the present invention may be implemented as a service to which an ophthalmologist, optometrist or private individual may subscribe. In the intended implementation, the subscriber would receive a compact disc (or other data carrier) carrying software to implement the teachings of the invention, instructions on monitor calibration and the use of each program, a display calibration device and a user input device.
[0064] The subscriber executes the supplied program to log onto the service (step 100 ) using a web browser and if the subscriber has not used the service before they are requested to register their computer with the server (step 102 ), following which the subscriber's computer display is calibrated using the display calibration device and procedure provided (step 104 ), following which the characteristics for that display are stored on the web server (step 106 ). The web server detects whether each profile stored replaces an existing profile or is the result of calibrating a new display. As aforementioned a calibration profile is identified by the Global Unique Identifier (GUID) assigned to the monitor (and the graphics card which runs it) by Microsoft Windows. Should a display need to be replaced for any reason, the replacement will need to be calibrated (and the web server detects this).
[0065] If the subscriber has used the service before, then the subscriber's display is validated (by comparing the GUID of that display with the GUID stored for that subscriber) (step 108 ). If this validation step should fail (for example because the subscriber has changed their display), then the subscriber is asked to complete the calibration process (step 104 ). If the validation step should be successfully passed, the profile for that display is retrieved (step 108 ).
[0066] A test to be undertaken is then selected (step 110 ), and while the server is generating the stimuli which will be used during the corresponding test (in particular whilst the server is adapting the stored reference test in accordance with the profile for the subscriber's display), the subscriber is presented with a form to fill in giving details for the person undertaking the test. This information is stored by the web server so that if that person should be re-tested it is only necessary to enter sufficient details to identify them (typically just their name).
[0067] Short video clips for the stimuli of an illustrative test to be performed are generated by the web server from the associated reference test by adapting that reference test in accordance with monitor calibration profile (step 112 ). During the test itself, the subscriber is asked to view a series of these clips that are streamed to the terminal (step 114 ) and to indicate, for example, in which direction (NE, NW, SE or SW) a coloured target moved. In the case of contrast acuity assessment, the subject is required to indicate the orientation of the target. In a more complex visual test that involves five buttons and five stimuli (i.e., one in each quadrant and one along the line of sight, see fig. xx) the subject's task may be to indicate which of the five stimuli contains a gap or which of the five stimuli flickers by pressing the appropriate response button to indicate the stimulus location. If the subject is not sure where the stimulus is located or cannot judge the direction of motion of the stimulus, the subject's instruction is to guess by pressing any of the buttons. This response can be entered either using the user input device or by clicking on-screen buttons displayed for this purpose. The web server will then display the next video clip until the test is completed and the measurement is made (step 116 ). The web server will then use a knowledge-based system to interpret the experimental measurements and suggest diagnosis (step 118 ). The results of several tests may be stored on the server and in some instances the results from more than one test are utilised for diagnosis.
[0068] The results of the test are stored on the web server and can be retrieved at a later date, if so desired. The server also has the ability to display significant longitudinal changes in a subject's response. This can be particularly useful in the detection of significant changes in performance even though the subject's responses remain within a normal range of expected performances. By this we mean that even though a subject's visual performance falls within the “normal range” established from measurements of a large number of “normal subjects”, a subject can have a statistically significant increase in thresholds (on re-testing months later), even though the new thresholds still fall within the “normal range”.
[0069] The system described herein may also usefully be employed to monitor disease progress or the effect of treatment in users with diagnosed conditions. Results can also be saved on the local computer in XML format (or any other format) for further processing. A number of reports can also be generated in PDF format suitable for printing.
[0070] As will now be apparent, the teachings of the present invention provide a means whereby vision testing (in particular, testing of the type known in the art as “advanced testing”) can be undertaken without the expense associated with purchasing dedicated processing machinery, and if necessary in the comfort of a user's home.
[0071] It will be appreciated that whilst various aspects and embodiments of the present invention have heretofore been described, the scope of the present invention is not limited to the particular arrangements set out herein and instead extends to encompass all arrangements, and modifications and alterations thereto, which fall within the scope of the appended claims. For example, it should be noted that the teachings of the present invention are not limited soley to CRT displays, but may instead be adopted for any other type of display, such as a liquid crystal display (LCD) or a surface-conduction electron-emitter display (SED).
[0072] It will also be apparent to persons skilled in the art that the physical location of functional components of the system described herein may be altered without departing from the scope of the invention. For example, whilst it is preferred that the server is configured to adapt tests and send adapted tests to the local user terminal for display, it will be apparent that the vision tests could alternatively be adapted at the local terminal. This could be accomplished with the local terminal computing the adaptations that need to be made to the reference test, or alternatively, the adaptations could be computed by the server and then provided to the user terminal for application to a given reference test.
[0073] It should also be noted that whilst the accompanying claims set out particular combinations of features described herein, the scope of the present invention is not limited to the particular combinations hereafter claimed, but instead extends to encompass any combination of features herein disclosed. | An embodiment of the invention relates to vision testing apparatus comprising: a local display ( 9 ); means ( 13 ) for obtaining data characterising the performance characteristics of said local display; means ( 9 ) for displaying to a user at said local display, a vision test that comprises an adaptation of a reference vision test; means ( 11 ) for registering user input in response to said displayed vision test; and means ( 9 ) for providing the user with the results of said displayed test; wherein said reference vision test comprises a test that is optimised for display on a high quality display, and the vision test for display at said local display is obtained by adapting said reference test in accordance with said characterising data so that the vision test displayed on said local display is a faithful reproduction of said reference test. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates generally to an adjustable hinge and, more particularly, to a hinge with an adjustment mechanism for controlling the opening angle of the hinge.
BACKGROUND
[0002] Most hinges designed for use in entry way doors or cabinet frames permit an opening angle 90 degrees or greater in order to permit sufficient access to the storage area for the user. Yet, there are some situations where it is desirable to use a hinge that restricts the angle to 90 degrees or less. For example, some households are equipped with a “sink” or “tip-out” tray mounted in an opening on the front panel of a kitchen sink cabinet, directly in-front of the sink tub. These types of tray mechanisms and their corresponding hinges are specially designed to permit the tray to pivot in and out of the tight space formed between the frame of the sink cabinet, counter top and sink tub.
[0003] While hinges for sink trays are known in the art, such prior art hinges are in the form of scissor-type hinges, such as the first and second prior art hinges 100 , 101 shown in FIGS. 1 and 2 , respectively. The first and second prior art hinges 100 , 101 incorporate a complex system of levers, panels, pins and coil springs and are relatively expensive because of their complexity and the amount of material they use. These prior art hinges are also designed to be mounted to the side walls of the sink cabinet, which reduces the space available for the sink tray.
[0004] Accordingly, it is desirable to have a hinge with a simple, compact and economical design that includes an adjustment mechanism for controlling the opening angle so it can be used in conjunction with cabinet or door systems—such as sink tray system or the like—where it is desirable to be able to adjust the permitted opening angle.
SUMMARY
[0005] In an embodiment, the hinge of the present application comprises a recessed cup and arm, the arm being pivotably connected to the cup. One end of the cup includes securing flanges adapted to engage a panel. At the opposite end of the cup a slanted rim is formed atop the recessed portion of the cup.
[0006] In one form, a mounting plate is formed on one portion of the arm and is adapted to be fastened to a cabinet frame or other mounting structure. At the other portion of the arm, referred to herein as the second portion, the arm is bent in order to form a curl that winds around a hinge pin secured in the cup, thereby permitting the arm to pivot relative to the cup. As the arm pivots from a closed position to an open position, an opening angle A is formed between the outer surface of the cabinet frame and inner surface of the panel.
[0007] An adjustable stopper disposed along a first axis X-X is threaded through a passage formed in the second portion of the arm. A second end of the stopper extends into the cup, and may be beveled in order to form a shoulder disposed at an angle relative to the first axis X-X. As the arm pivots to the closed position, the shoulder contacts the rim, whereby the rim operates as a abutment for the stopper.
[0008] The hinge may be incorporated in a sink tray system where a sink tray or tip-out tray is mounted to the inner surface of the cabinet panel using fastening screws or the like. It will be appreciated that the hinge and its corresponding adjustment mechanism permits the tray to pivot in and out of the tight space formed between the frame of the sink cabinet, counter top and sink tub.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For the purpose of facilitating an understanding of the subject matter sought to be protected, there is illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages, should be readily understood and appreciated.
[0010] FIG. 1 is a partial cross-sectional view of a first prior art sink tray hinge.
[0011] FIG. 2 is a partial cross-sectional view of a second prior art sink tray hinge.
[0012] FIG. 3 is a partial cross-sectional view of an embodiment of the hinge of the present application where the hinge is shown in the closed position.
[0013] FIG. 4 is a partial cross-sectional view of the hinge of FIG. 3 , but showing the hinge in the open position.
[0014] FIG. 5 is an enlarged partial cross-sectional view of the hinge of FIG. 4 , but showing the components of the self-closing/self opening functions in more detail.
[0015] FIG. 6 is a partial plan view of the hinge of FIG. 4 .
[0016] FIG. 7 is a partial cross-sectional view of the hinge of FIG. 3 incorporated with a typical sink tray system having a tray, frame and panel.
[0017] FIG. 8 is a partial cross-sectional view similar to FIG. 7 , but showing the hinge in the open position.
[0018] FIG. 9 is an enlarged front view of an embodiment of a multi-adjustable hinge.
[0019] FIG. 10 is an enlarged front view of an embodiment of a safety bracket.
[0020] FIG. 11 is a perspective view of the safety bracket of FIG. 10 incorporated with a typical sink tray system.
DETAILED DESCRIPTION
[0021] While the present invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to embodiments illustrated.
[0022] Referring to FIGS. 3-8 , there is illustrated a hinge 10 comprising a recessed cup 13 and an arm 30 extending into the cup 13 . The cup 13 is inserted into a bore 19 formed in a cabinet panel 200 or the like. In one form, one end of the cup 13 includes securing flanges 17 extending outwardly from opposing sides of the cup 13 . Each flange 17 may include an aperture for receiving fastening screws 18 or the like for sercurment to cabinet panel 200 . At the opposite end of the cup 13 a slanted rim 15 is formed atop a recessed portion 14 of the cup 13 . It will be appreciated that the cup 13 can be formed in many ways, such as, for example, from a single pressed piece of sheet metal or casting.
[0023] In an embodiment, arm 30 has a first portion 31 and second portion 34 . The first portion 31 includes a mounting plate 32 adapted to be secured over a frame 250 or other mounting structure, such as those found in typical sink cabinets or the like. The second portion 34 of the arm 30 extends into the cup 13 . In one form, the second portion 34 terminates in a curl 35 that winds around a hinge pin 40 secured in the cup 13 , thereby permitting the arm 30 to pivot relative to the cup 13 . As the arm 30 pivots from a closed position to an open position, an opening angle A is formed between the outer surface of the cabinet frame 250 and inner surface of the panel 200 . It will be appreciated that the arm 30 , including the first and second portions 31 , 34 may be pressed or cast from a single piece of sheet metal having multiple bends.
[0024] The end of the curl 35 is notched in order to define opposing projections 36 . A coil spring 60 winds around a second pin 70 secured in the cup 13 and includes two legs 62 that extend toward and engage projections 36 . It will be appreciated that the interaction between the legs 62 of the coil spring 60 and projections 36 effectuate a self-opening and self-closing function. In particular, as the arm 30 pivots from the closed position toward the open position the free ends of the legs 62 pass over corners 37 of the projections 36 generating a moment force which biases the arm 30 towards the open position. Likewise, as the arm 30 pivots from the open position toward the closed position, the free ends of the legs 62 pass over corners 37 of the projections 36 generating a moment force which biases the arm 30 towards the closed position.
[0025] Referring to the embodiments shown in FIGS. 3-8 , an adjustable stopper 50 extending along a first axis X-X is threaded through a passage 38 formed in an intermediate portion of the arm 30 . The stopper 50 may be in the form of a machine screw with a first end 52 in the form of a Phillips drive head or the like, although other structures for stopper 50 may be used as well. The passage 38 penetrates and extends slightly beyond the thickness of the arm 13 in order to permit a sufficient number of threads 39 to be engaged by the stopper 50 . Preferably, at least 3 or 4 thread 39 rotations should formed in the passage 38 to ensure the stopper 50 doesn't slip or otherwise disengage during normal operation.
[0026] In an embodiment, a second end 55 of the stopper extends toward the cup 13 . The termination of the second end 55 may be beveled or chamfered in order to form an angled cross section having a shoulder 58 disposed at an angle relative to the first axis X-X. As the arm 30 pivots to the closed position, the shoulder 58 contacts the rim 15 , whereby the rim operates as an abutment surface for the stopper 50 . In one form, the cup 13 and stopper 50 are shaped such that the contacting surfaces of the shoulder 58 and rim 15 are disposed substantially parallel to each other to provide increased reliability by decreasing component wear. In that regard, such an arrangement maximizes the area of contact between the shoulder 58 and rim 15 , which prevents excess pressure and denting of the rim 15 .
[0027] As shown in FIGS. 7-8 , the hinge 10 may be incorporated in a typical sink tray system 100 where a sink tray or tip-out tray 210 is mounted to the inner surface of the cabinet panel 200 using fastening screws or the like. The fact that the stopper 50 acts to restrict opening angle A permits the tray 210 to pivot inwardly and outwardly of the generally tight space formed between the frame 250 of the sink cabinet, counter top (not shown) and sink tub (not shown).
[0028] In a method for installing the hinge 10 in a sink tray system 100 , the user begins by inserting the cup 13 into a bore 19 formed in an inner surface of a cabinet panel 200 and securing the flanges 17 to the panel 200 using fastening screws. In a sink tray system 100 incorporating two hinges 5 , one hinge 10 is installed on each end of the inner surface of the panel 200 , and each of the steps below are repeated for each hinge 10 .
[0029] The user may then secure the mounting plate 32 to a surface of the frame 250 , also using fastener screws or the like. The opening angle A, (i.e. range of opening) can be controlled by manually rotating the stopper 50 using a screw driver or the like, which, depending on the direction of rotation, causes the stopper 50 to thread towards the cup 13 along the first axis X-X, or away from the cup 13 , also along the first axis X-X. It will be appreciated that the permitted opening angle A is minimized when the stopper 50 is fully inserted. In an embodiment, the desired opening angle A-A, may be between 20 and 70 degrees, depending on how far the user desires the tray 210 to tip outwardly toward the user. For example, a opening angle A-A too large (generally greater than 90 degrees) may permit the contents of the tray 210 to spill out, while a opening angle A-A too small may fail to permit the user sufficient access to the contents within the tray 210 .
[0030] Securement of the tray 210 to the inner surface of the panel 200 is achieved by applying fasteners, such as a screw, to mounting slots (not shown) formed on the opposing surface of the tray 210 . It will be appreciated that the cup 13 is substantially recessed in the bore 19 and may be arranged to lay substantially flush with an inner surface of the panel 200 , thereby permitting additional space for the tray 210 along the inner surface of the panel 200 . It will also be appreciated that in a fully assembled sink tray system 100 , hinge 10 is substantially concealed behind the panel 200 for aesthetic purposes. Also, in one form, the hinge 10 of the current application permits the tray 210 to be sized in a manner that takes full advantage of the space available in the sink cabinet. In that regard, the tray 210 can be sized to extend substantially the full distance between the side walls 103 .
[0031] In one form, the sink tray system 100 may further comprise a safety bracket 410 mounted at either end of the panel 200 to protect against safety hazards associated with excess force being applied to the panel 200 or tray 210 . For example, an unattended child who grasps the panel 200 or tray 210 in an attempt to swing or climb may cause forces to be applied to the hinge 10 beyond its weight capacity, which could result in breakage of the hinge 10 at the hinge pin 40 or the like, thereby creating a potential safety hazard. Accordingly, referring to FIGS. 10 , 11 safety brackets 410 may be mounted at either end of the panel 200 . In one form, the safety bracket 410 comprises an extension 440 with a foot 420 at one end and a catch 450 at the other end. The foot 420 may be provided with two apertures 425 that receive wood screws 430 for fastening the safety bracket 410 to the panel 200 . The catch 450 may be in the form of a dowel or the like and can be secured to the extension 440 by means of a machine screw that engages an aperture, as shown in FIG. 11 . The safety bracket 410 should be positioned on the panel 200 in a manner that causes the catch 450 to overlap with a vertical member 255 of the cabinet frame 255 . In this form, as the hinge 10 and panel 200 pivot toward the open position, the catch 450 is positioned to abut the inner surface of the vertical member 255 of the cabinet frame, thereby preventing the panel 200 from pivoting too wide relative to the vertical member 255 .
[0032] In an alternative embodiment shown in FIG. 9 , a multi-adjustable hinge 310 may incorporate a two-piece adjustable arm 330 having a mounting plate 332 and jacket 331 having sleeves 333 folded from a single piece of sheet metal. The sleeves 333 are adapted to slideably engage a lower portion 334 that extends into the cup 13 . An elongated opening 339 centered in the lower portion 334 is sized to receive an adjustment screw 341 adapted to pass through the elongated opening 339 towards an aperture (not shown) in the rear portion of the jacket 331 . In one form, threads formed in this aperture are sized to threadably engage the threads of the adjustment screw 341 in a well known manner. The adjustable stopper 50 is threadably engaged through the passage 38 , which is substantially centered in the lower portion 334 of the arm below the elongated opening 339 . It will be appreciated that the cup 13 , spring loaded self-opening and self-closing and angle adjustment features of the alternative embodiment shown in FIG. 9 operate with a design and structure substantially the same to those shown in the embodiment of FIGS. 3-8 .
[0033] In operation of the alternative embodiment shown in FIG. 9 , loosing of the adjustment screw 341 enables the jacket 331 and mounting plate 332 to shift vertically relative to lower portion 334 , thereby permitting vertical adjustment of the surfaces relative to each other to which the mounting plate 332 and cup 13 are attached. For example, the additional adjustment feature of the multi-adjustable hinge 310 may permit vertical adjustment of the cabinet frame 250 relative to the panel 200 , should the multi-adjustable hinge 310 be used with the a typical sink tray system 100 , such as those shown in FIGS. 7-8 . The adjustment screw 334 can be turned for tightening purposes in order to prevent movement of the mounting plate 332 relative to the lower portion 334 when they have reached their desired relative positions.
[0034] It will be appreciated that while the components of the adjustable and multi-adjustable hinges 10 , 310 are made of cold rolled steel in one form, other sufficiently rigid materials may also be used, such as plastics or metals.
[0035] The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be appreciated that changes and modifications may be made without departing from the broader aspects of applicants' contribution. | A hinge, comprising a cup having a rim and an arm pivotably connected to the cup, wherein the arm is permitted to pivot between a closed position and an open position, the open position defining a opening angle between the cup and arm. An adjustable stopper coupled to the arm is engagable with the rim whereby the opening angle is controlled by adjustment of the stopper. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a bearing seal assembly for a concrete auger mixer.
[0002] Concrete auger mixers have been utilized to mix concrete in a continuous process. They include an elongated housing having a rotating auger therein. The housing usually has a flexible bottom and a rigid top and is arcuate at least in the bottom portion to conform to the flightings on the auger.
[0003] The auger housing is usually elevated at the discharge end and is lowered at the input end so that the concrete ingredients are placed within the housing at the lower end and is raised by the auger and mixed as it approaches the discharge opening at the upper end of the auger.
[0004] Problems have been encountered in providing a satisfactory seal of the lower end of the auger to the lower end of the auger housing. The auger rotates within the lower end wall of the auger housing and the cementations materials and water directed downwardly by gravity seep into the bearing and ultimately damage the bearing because of the abrasive nature of the cementatious material.
[0005] It is therefore desirable to provide an improved seal preventing the cementatious material from entering the bearing from within the auger housing.
[0006] Therefore a primary object of the present invention is the provision of an improved bearing seal for concrete auger mixers.
[0007] A further object of the present invention is the provision of a bearing seal for a concrete auger mixer that utilizes a stationary seal and a rotating seal which engage one another and provide a seal therebetween.
[0008] A further object of the present invention is the provision of a stationary seal that remains stationary relative to the end wall of the housing mixer and a rotating seal that rotates with the auger, the two seals engaging one another and providing a seal to prevent cementations material from exiting the mixing housing chamber.
[0009] A further object of the present invention is the provision of a seal comprising a fixed sealing member and a fixed flexible member, and providing a rotating sealing member and a rotating flexible member. The fixed sealing member and the rotating sealing member include sealing surfaces that engage one another and prevent cementatious material from exiting the auger housing.
[0010] A further object of the present invention is the provision of a flexible plate outside the lower housing wall which permits a slight movement of the angle of the auger relative to the mixer housing wall so as to permit slight flexing thereof.
[0011] A further object of the present invention is the provision of a bearing for permitting the rotation of the auger relative of the end wall of the mixer, the seal being provided between the bearing and the cementatious material.
[0012] A further object of the present invention is the provision of a seal and bearing for a concrete auger mixer which is economical to manufacture, durable in use, and efficient in operation.
[0013] A further object of the present invention is the provision of a method for sealing the cementatious material within the mixer housing during rotation of the auger.
[0014] A further object of the present invention is the provision of a bearing which utilizes lapped surfaces for engaging one another to cause the seal.
SUMMARY OF THE INVENTION
[0015] The foregoing objects may be achieved with an auger mixer for mixing a concrete mix comprising an elongated mixer housing having a first end and a second end. The mixer housing has a mixing chamber for mixing the concrete mix therein. A mixing auger is disposed within the mixing chamber and has an auger shaft. The auger shaft has a longitudinal shaft axis extending from the first end to the second end of the mixer housing. A power source is connected to the mixing auger for rotating the mixing auger about the longitudinal shaft axis of the shaft. The mixer housing has a first end wall adjacent the first end of the housing. A bearing assembly mounts one end of the auger shaft to the first end wall of the housing for rotation relative to the first end wall about the shaft axis. A seal assembly comprises a stationary seal remaining stationary relative to the first end wall and a rotating seal rotating about the auger shaft axis. The stationary seal and the rotating seal contact one another to create a seal preventing the concrete mix from exiting the mixing chamber and moving toward the bearing assembly.
[0016] According to another feature of the present invention the fixed seal comprises a first fixed seal member and a second fixed seal member. The rotating seal comprises a first rotating seal member and a second rotating seal member.
[0017] According to another feature of the present invention the first fixed seal member and the first rotating seal member are made of a resilient material deformed to engage and urge the second fixed member and the second rotating member respectively into frictional engagement with one another to create the seal.
[0018] According to another feature of the present invention the first fixed and rotating seal members are made of rubber and the second fixed and rotating seal members are made of steel.
[0019] According to another feature of the present invention the stationary seal comprises a sealing surface and the rotating seal comprises a sealing surface frictionally engaging and sealing against the sealing surface of the stationary seal.
[0020] According to another feature of the present invention the sealing surfaces of the stationary seal and the rotating seal are comprised of steel.
[0021] According to another feature of the present invention the sealing surfaces of the stationary seal and the rotating seal are circular.
[0022] According to another feature of the present invention the sealing surfaces of the stationary seal and the rotating seal are cone shaped and have outer circular cone ends. The cone shaped sealing surfaces of the stationary and rotating seals are oppositely opposed to one another so that only the outer circular cone ends contact one another.
[0023] According to another feature of the present invention a flexible stationary seal member and a flexible rotating seal member engage the stationary sealing surface and the rotating sealing surface respectively and bias the stationary sealing surface and the rotating sealing surface toward one another.
[0024] According to another feature of the present invention a steel plate attaches the bearing assembly to the first end wall of the housing. A compressible plate is between the steel plate and the first end wall. A securing member secures the steel plate and the compressible plate to the first end wall whereby the compressible plate permits flexing of the steel plate and the first end wall relative to one another so as to permit slight movement of the angular disposition of the shaft axis relative to the end wall.
[0025] According to the method of the present invention a seal assembly is placed between the first end wall and the rotating shaft. The seal assembly comprises a stationary seal and a rotating seal. The method includes maintaining the stationary seal stationary with respect to the first end wall and rotating the rotating seal about the rotating axis of the rotating auger shaft. The stationary seal and the rotating seal are frictionally contacted to provide a sealing engagement therebetween for preventing concrete mix from exiting the mixing chamber through the first end wall.
[0026] According to another feature of the method of the present invention a stationary seal having a circular stationary sealing surface and a rotating seal having a circular rotating sealing surface contact one another.
[0027] According to another feature of the present invention the circular rotating surface and the circular stationary surface are biased in frictional engagement with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a sectional view of an auger mixer of the present invention.
[0029] FIG. 2 is a sectional view of the bearing assembly of the present invention.
[0030] FIG. 3 is an exploded perspective view of the lapped seal members used in the present application.
[0031] FIG. 4 is an enlarged detailed sectional view taken along line 4 - 4 of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Referring to FIG. 1 , a concrete auger mixer 10 embodying the present invention is shown. Mixer 10 includes a mixer housing 12 having a rigid upper member 14 and a flexible lower member 16 . A first end wall 18 and a second end wall 20 together with the upper member 14 and the flexible lower member 16 form a mixing chamber 22 in which concrete is to be mixed. The mixing chamber 22 includes an inlet opening 24 adjacent the lower end wall 18 and a discharge opening 26 adjacent the upper end wall 20 . A hopper 28 is provided for dropping the concrete mix into the lower end of the auger mixer 10 . The concrete mix may vary, but usually includes cement, aggregate, water, and possibly other ingredients such as pigments.
[0033] Rotatably mounted within the mixing chamber 22 is an auger 30 having an auger shaft 32 and auger flightings 34 . The auger shaft 32 is adapted to rotate about its longitudinal axis 32 . A motor 36 is attached to the upper end of the auger shaft 32 . A motor bearing 38 (not shown) provides the rotation of shaft 32 in the end wall 20 as it is rotated by motor 36 . The bearing 38 does not encounter substantial pressure from the cementatious material within the housing 22 because it is located at the upper end of the mixing auger 10 .
[0034] However, a bearing assembly 40 is used to mount the lower end of the auger shaft 32 to the lower end wall 18 .
[0035] Referring to FIG. 2 , a wear plate 42 is in facing engagement with the interior of lower end wall 18 . Wear plate 42 includes an annular flange 44 . On the opposite side of end wall 18 is a flexible plate 46 preferably made from rubber, but possibly made from other flexible material. A bearing housing 48 includes a housing plate 50 which is in facing engagement with the flexible plate 46 and holds the flexible plate 46 against the end wall 18 . Bearing housing 48 also includes a housing cylinder 52 which includes a grease zerk 54 therein. Bolts 56 bolt the flexible plate 46 between the housing plate 50 and the end wall 18 , and also bolt the wear plate 42 against the end wall 18 . The end wall 18 , the flexible plate 46 , the housing plate 50 , and the internal wearing plate 42 all include a circular opening therein which together form a clearance opening 58 .
[0036] Mounted telescopically within the lower end of shaft 32 is a tail shaft 60 which is held in attachment to the auger shaft 32 by means of a connecting bolt 62 . Thus tail shaft 60 rotates in unison with auger shaft 32 .
[0037] Tail shaft 60 includes an internally facing shoulder 64 . The term internally refers to facing in the direction of the mixing chamber 22 . Tail shaft 60 and bearing housing 48 together create an annular seal cavity 66 which contains a stationary seal 68 and a rotating seal 70 . Stationary seal 68 includes a stationary steel ring 72 ( FIG. 4 ) and a stationary flexible ring 74 . The rotating seal 70 includes a rotating steel ring 76 and a rotating flexible ring 78 . Together the stationary seal 68 and the rotating seal 70 comprise a heavy duty seal manufactured by CR Services, 735 Tollgat Road, Elgin, Ill. 60123-9332 under the service kit number 16904. These seals are also referred to as “lapped seals”. They are shown in greater detail in FIGS. 3 and 4 . Stationary steel ring 72 includes a horizontal ring 80 and a vertical ring 82 . The vertical ring 82 has a cone shaped surface 84 thereon. Cone shaped surface 84 has an outer cone edge 86 which forms the outer peripheral edge of a tapered seal surface 88 .
[0038] The rotating steel ring 76 is similarly constructed and includes a horizontal ring 80 , a vertical ring 82 , a cone shaped surface 84 , an outer cone edge 86 , and a tapered seal surface 88 . It should be noted that only the outer peripheral edges 86 of the two steel members 72 , 76 engage one another around the entire periphery of the rings 72 , 76 . As the friction between the two causes wear of the tapered seal surface 88 , the wear merely results in a flatter surface being formed between the steel members 72 , 76 . Flexible members 76 , 78 are enclosed within seal cavity 66 and are distorted so that they are loaded and are angularly presented so that they force or bias the two steel members 72 , 76 into engagement with one another as shown in FIG. 4 . The lapped surface 86 provides a seal that prevents the cementatious material from entering between the two seal members 72 , 76 .
[0039] The tail shaft 60 also includes an outwardly facing shoulder 90 that faces away from the end wall 18 . A bearing comprising an outer race 92 , an inner race 94 and a tapered bearing 96 engages this outwardly facing shoulder 90 . Similarly, a second bearing comprising an outer race 98 , an inner race 100 , and oppositely tapered bearings 102 is spaced outwardly from the first bearing member described. The bearing housing 48 includes an outwardly presented housing shoulder 104 and an inwardly presented housing shoulder 106 which engaged the bearings and hold them in place. The two bearings are spaced apart from one another by a bearing cavity 108 . A spacer washer 110 surrounds the outwardly presented end of the tail shaft 60 . A slotted nut 112 is threaded over the outer threaded end of tail shaft 60 and is further held in place by means of a cotter pin 116 . In addition the slotted nut 112 includes slots 114 for receiving cotter pin 116 and has a hexagonal configuration for use of a wrench. A dust cap 118 is in covering relation over the nut 112 and is held in place by a securing ring 120 that includes bolts 122 . Tail shaft 60 includes a shank portion 124 that forms an internal margin of a donut shaped cavity 108 that extends between the two bearings.
[0040] Grease is inserted through zerk 54 into the cavity 108 and then forced through bearing 96 into a donut shaped cavity 126 , then between seal 68 and seal 70 into cavity 66 and continuing into cavity 130 .
[0041] In operation, the motor 36 rotates the auger shaft 32 so as to cause the concrete mix to be moved upwardly from the inlet opening 24 towards the discharge opening 26 . The rotation of the auger 32 and flightings 34 causes the concrete mix to be thoroughly mixed together before it is discharged from the discharge opening 26 .
[0042] The concrete mix includes a slurry formed by the water in the mix, and this slurry drops by gravity toward the bearing assembly 40 . It can enter between a lower end flange 128 through an L-shaped limited cavity 130 . While the slurry can enter this cavity 130 , larger particles such as aggregate are too large to enter the cavity 130 . However, when the slurry reaches the sealed cavity 66 ( FIG. 4 ), it is prevented from further infiltration into the bearing assembly 40 by the contact between the stationary seal 68 and the rotating seal 70 . It should be noted that auger shaft 32 , lower end flange 128 , and rotating seal 70 rotate in unison together with the tail shaft 60 and the slotted nut 124 .
[0043] The end wall 18 , the plates 42 , 46 , 50 , and the entire bearing housing 48 remain stationary as well as the stationary seal 68 .
[0044] An important feature of the present invention is the frictional engagement between the rotating steel ring 76 and the stationary steel ring 72 . These two rings engage one another at the outer cone edge 86 . Through extended use, these surfaces will wear, but the angled nature of the sealing surfaces 84 take up the wear and prevent the seal from losing its sealing capability. Thus the cementatious slurry that enters through limited cavity 130 never progresses beyond the seal cavity 66 . This cementatious material is also trapped between the two flexible sealing members 74 , 78 .
[0045] The bearings 96 , 102 also are protected from the cementatious slurry material, and therefore their wear in response to the abrasive cementatious slurry is minimized.
[0046] The flexible plate 46 permits slight flexing of the auger shaft 32 with respect to the angle at which the tail shaft 60 passes through the wall opening 58 . This provides tolerance for rotational movement of the shaft 32 .
[0047] The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives. | An auger mixer for mixing a concrete mix includes an elongated mixer housing having a mixing chamber for mixing the concrete mix therein. A mixing auger is rotatably mounted within the mixing chamber. A bearing assembly mounts one end of the auger shaft to the mixer housing. A seal assembly comprising a stationary seal remains stationary relative to the mixer housing and a rotating seal rotates with the auger. The stationary seal and the rotating seal contact one another to create a seal preventing the concrete mix from exiting the mixing chamber and moving toward the bearing assembly. | 1 |
This application is a continuation of application Ser. No. 08/528,524 filed Sep. 15, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a retaining structure of an O-ring which is used for sealing a gap between an electrical device and an electrical connector to be mounted directly on the electrical device.
2. Description of the Prior Art
Hitherto, in an electrical connector which is mounted directly on an electrical device, in order to maintain the device airtight or watertight, a gap between an electrical connector and the device is sealed by causing an O-ring to intervene. As in FIG. 8, which shows in a schematic sectional view is shown of airtight-type coaxial connector K, as disclosed in Japanese Utility Model Application Laid Open No. HEI 4-115782.
In this airtight-type coaxial connector K, an O-ring d is inserted into an O-ring-receiving groove c for maintaining a sealing property at a device mounting surface b of a connector housing a.
However, in such O-ring-receiving groove c, the O-ring d tends to slip off from the O-ring-receiving groove, while assembling work for the connector housing a is conducted. For the above reason, the operator must perform assembling work while giving attention that the O-ring d is retained in the groove consequently, there arises the problem that assembling efficiency of the device deteriorates.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide a retaining structure for an O-ring in which a structure of an O-ring-receiving groove on a device is improved so that an O-ring is temporarily connected to the inside of the O-ring-receiving groove for the connector housing, thus to prevent the O-ring from slipping off from the O-ring-receiving groove accordingly, while mounting work of the connector is performed, with the result that the connector assembling work can be performed accurately and easily.
According to one aspect of the present invention, for achieving the above-described object there is provided a retaining structure for an O-ring in which a connector housing is mounted on an electrical device through an O-ring to seal the gap between the connector housing and an electrical device, the retaining structure comprising a pressing projection provided for an inner peripheral wall of an O-ring-receiving groove of the connector housing, and a notch portion provided for an outer peripheral wall of the O-ring-receiving groove opposite the pressing projection, wherein the retaining structure of the O-ring causes the O-ring inserted into the O-ring-receiving groove to be held between the pressing projection and the outer peripheral wall.
According to another aspect of the present invention, there is provided an O-ring retaining structure in which, when the minimum width of the O-ring-receiving groove is W, the minimum depth of the O-ring-receiving groove is F, the minimum diameter of the O-ring is D, and the maximum crosssectional area of the O-ring is R, a gap T 1 between a pointed end of the pressing projection and a bottom of the notch portion, and a projection length T 2 from the inner peripheral wall to the pointed end of the pressing projection are established so as to satisfy the following conditions;
T.sub.1 >R/F
T.sub.2 >W-D.
It is preferable that the connector directly mounted on the device is a shielded connector having a metallic shell.
As described above, there is an O-ring retaining structure according to the present invention in which both the pressing projection and the notch portion are provided for the O-ring-receiving groove of the connector housing so that the O-ring can be held between the pressing projection and the outer peripheral wall of the O-ring-receiving groove by virtue of the elasticity of the O-ring itself.
Namely, the O-ring inserted into the O-ring-receiving groove bends outwardly to a diameter greater than diameter of the inner peripheral wall of the O-ring-receiving groove because the O-ring is pressed by the pointed end of the pressing projection. At this time, since the notch portion is provided in the outer peripheral wall opposite the pressing projection, the bent portion of the O-ring is received into the notch. There are two contacting portions, P 1 and P 2 , in which an outer peripheral surface of the O-ring comes into contact with the outer peripheral wall of the O-ring receiving-groove, whereby a pressing force is effected. Accordingly, the O-ring is temporarily connected positively at three locations in such a way that the O-ring is held by the pointed end of the pressing projection and the two contacting portions, P 1 and P 2 of the outer peripheral wall. In the handling manipulation when the connector housing is mounted on the casing, the O-ring is not easily removable from the O-ring-receiving groove. Accordingly, the assembling efficiency of the device is remarkably improved.
The above and further objects and novel features of the invention will be more fully understood from the following detailed description when the same is read in connection with the accompanying drawings. It should be expressly understood, however, that the drawings are for purpose of illustration only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a connector directly mounted on the device according to one embodiment of the present invention;
FIG. 2 is a vertical sectional view showing a connector directly mounted on the device of FIG. 1;
FIG. 3 is a sectional view showing a connector housing and a metallic shell of FIG. 1;
FIG. 4 is a bottom view showing a device mounting surface of the connector housing of FIG. 1;
FIG. 5 is a sectional view showing a shape of an O-ring-receiving groove of FIG. 4;
FIG. 6 is an explanatory view showing a pressing projection and a notch portion which are provided for the O-ring-receiving groove of FIG. 4;
FIG. 7 is an explanatory view showing a holding condition of the O-ring between the pressing projection and the notch portion of the O-ring-receiving groove of FIG. 6; and
FIG. 8 is an explanatory view showing an O-ring of a conventional connector directly mounted on the device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will now be described in detail referring to the accompanying drawings.
FIG. 1 is a sectional view showing a connector A directly mounted on a device according to one embodiment of the present invention.
FIG. 2 is a vertical sectional view showing the connector A directly mounted on the device of FIG. 1.
In the connector A, which is directly mounted on the device, a metallic shell 2, for use in shielding is interiorly mounted on the connector housing 1, enabling the connector housing 1 to be mounted directly to the conductive casing 3 of an electrical device of the motor, and so on.
In the connector housing 1, a flange 5 to be mounted on the casing 3 is formed around on one end of a cover portion 4 receiving an outer cylindrical portion of the other connector. A mounting hole 6 is bored in four corners of the flange 5. On the inside of the cover portion 4, a cylindrically shaped terminal metallic parts accommodating member 7 is provided so as to penetrate the substantially central part of the flange 5. As shown in FIG. 3, the metallic shell 2 is fitted on the periphery of the terminal metallic parts-accommodating member 7. The metallic shell 2 is fitted on the terminal metallic parts-accommodating member 7, by a cylindrical body portion 2a of the shell being inserted into a shell receiving groove 10 which is provided for the peripheral wall 7a of the terminal metallic parts-accommodating member 7.
Terminal metallic parts 9 are accommodated on the inside of the terminal metallic parts accommodating member 7, both ends of which are opened. A rubber plug 11 is put on the outside of the peripheral wall 7a of the terminal metallic parts-accommodating member 7. The terminal metallic parts 9 and the metallic shell 2 are connected to the terminals and the shielding members of the other connector (not illustrated) respectively.
As shown in FIG. 4, a substantially circularly shaped O-ring-receiving groove 12 is formed around a device-mounting surface 5a of the flange 5. The connector housing 1 and the casing 3 are sealed therebetween, causing the O-ring 13 to be inserted into the O-ring-receiving groove 12 when the connector housing 1 is mounted on the casing 3.
As shown in FIG. 5, the O-ring-receiving groove 12 comprises an inner peripheral wall 12a, an outer peripheral wall 12b and a bottom wall 12c so as to be formed as a rectangularly shaped groove in section. As shown in FIGS. 4 and 6, an angularly shaped pressing projection 14, which is offset from the inner peripheral wall 12a of the O-ring-receiving groove 12 toward the outer peripheral wall 12b thereof, is positioned diametrically opposite sides of the flange 5, along with a V-shaped notch portion 15 is formed in the outer peripheral wall 12b opposite the respective pressing projections 14.
As shown in FIG. 6, when the minimum width of the O-ring-receiving groove 12 is W, the minimum depth of the O-ring-receiving groove 12 is F, the minimum diameter of the O-ring 13 is D, and the maximum sectional area of the O-ring 13 is R, a gap T 1 between a pointed end 14a of the pressing projection 14 and a bottom 15a of the notch portion 15, and the projection length T 2 from the inner peripheral wall 12a to the pointed end 14a of the pressing projection 14 are established so as to satisfy the relationship for the following condition;
T.sub.1 >R/F
T.sub.2 >W-D.
Namely, in the present embodiment, the width of the O-ring-receiving groove 12 is the length between the inner peripheral wall 12a and the outer peripheral wall 12b: W aaf 3.25 mm+0.25 mm, W min =3.25 mm-0 mm, W=3.25 mm.
The depth of the O-ring-receiving groove 12 is the height from the bottom wall 12c to the device mounting surface 5a, it is 1.8 mm±0.05 mm, ∴F=1.75 mm.
The diameter of the thickness for the O-ring 13 is 2.4 mm±0.07 mm, ∴D=2.33 mm.
The maximum sectional area of the O-ring 13 is R=4.79 mm 2 .
Consequently, T 1 and T 2 are established as follows: ##EQU1##
As described above, the pressing projection 14 and the notch portion 15 are established so that as shown in FIG. 7, the O-ring 13 is held between the pressing projection 14 and the outer peripheral wall 12b of the O-ring-receiving groove 12 by virtue of the elasticity of the O-ring 13 itself, when the O-ring in inserted into the O-ring-receiving groove 12.
Namely, the O-ring 13 bends outward because the O-ring 13 is pressed by the pointed end 14a of the pressing projection 14. At this time, since the notch portion 15 is provided for the outer peripheral wall 12b opposite the pressing projection 14 and, the bent portion of the O-ring 13 is received in the notch 15, there are two contacting portions, P 1 and P 2 , in which an outer peripheral surface of the O-ring 13 comes into contact with the outer peripheral wall 12b of the O-ring-receiving groove 12, whereby a pressing force is is effected. Accordingly, the O-ring 13 is temporarily connected positively at these locations in such a way that the O-ring 13 is held by the pointed end 14a of the pressing projection 14 and the two contacting portions, P 1 and P 2 , of the outer peripheral wall 12b. In the handling manipulation wherein the connector housing 1 is mounted on the casing 3, the O-ring 13 is not easily removable from the O-ring-receiving groove 12.
In the above described embodiment, the pressing projection 14 and the notch portion 15 are provided for the O-ring-receiving groove 12 at two locations, however, the locations and the number of pressing projections and limited. Namely, numbers of three or more locations are permitted and the places where they are to be provided are not restricted particularly. Further, the shape of the O-ring-receiving groove, which is provided for the flange of the connector housing might not be limited as a circular shape. Instead, it is permitted that the O-ring-receiving groove may have another shape, such as an ellipse.
As described above, according to the present invention, since both the pressing projection and the notch portion are provided for the O-ring-receiving groove of the connector housing, the O-ring is temporarily connected in a stable manner so as to be held at three places including the one pointed end of the pressing projection resulting from the notch portion and two contacting projections. Accordingly, the assembling efficiency is remarkably improved because the O-ring does not get out of the O-ring-receiving groove during assembly of the connector.
Further, by rendering the establishment of qualification to both the O-ring-receiving and the O-ring groove, as described in regard to FIG. 6, there are advantages in that the sealing function of the O-ring is not adversely effected because the O-ring can be deformed in the stable manner on a inside of the O-ring-receiving groove, even if the O-ring is compressed so as to effectively mount the connector on the other device.
While preferred embodiments of the invention have been described using specific terms, such description is for illustrative purpose only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. | A retaining structure for a flexible O-ring which is used for sealing a gap between an electrical device and an electrical connector to be mounted directly on an electrical device, comprises a pressing projection provided on an inner peripheral wall of an O-ring-receiving groove for a connector housing, and a notch portion provided for an outer peripheral wall of the O-ring-receiving groove on the opposite side of the pressing projection, wherein an O-ring inserted into the O-ring-receiving groove is held by engagements by contacting portions defined by a pointed end of the pressing projection and oppositely disposed contacting portions P 1 and P 2 on an outer peripheral wall. | 5 |
BACKGROUND OF THE INVENTION
The present invention refers to direct current electromotors, in particular direct current electromotors having small dimensions, comprising a collector plate attached to a shaft, a plurality of collector wires held by the collector plate and accumulated to a collector sleeve, and a capacitor disk also arranged in the region of the collector plate, the contact pads of which each are in an electrical connection to at least one associated collector wire in a respective coordination.
Direct current electromotors of that kind having capacitor disks are used where a prolongation of the motor life is assumed, since the use of the capacitor disk leads to less formation of sparks at the collector. Capacitor disks of that kind (e.g. CLL disks) are mostly made of a special ceramic material and comprise suitable contact pads. In the formerly used constructions, the collector plate was put from the front onto the collector plate and a connection was enabled by a separate wiring between the collector wires and the contact pads of the capacitor disk. In a further embodiment of the prior art, it is provided that the capacitor disk was set onto the rear side of the collector plate and that the capacitor disk has star-shaped connection wires, which were bent forwardly over the outer circumference of the collector plate so that they were brought into contact with the collector wires.
A decisive disadvantage of this construction is amongst others that it is not suitable for use in motors having a diameter smaller than 15 mm because of the space required. Moreover, the joining technique between collector wires and capacitor disk requires much effort so that there was an endeavor to simplify the connection.
SUMMARY OF THE INVENTION
Thus, it is the object of the present invention to provide a direct current electromotor of the above-mentioned kind which can also be manufactured with small outer diameters and which has a simple design.
This object is solved in accordance with the invention in that the capacitor disk with its contact pads is directly set onto the collector wires and is connected therewith. Thus, the invention does without additional contacting elements between the capacitor disk and the collector wires and sets the capacitor disk directly onto the collector wires. Through this, the diameter range covered by the collector wires can be used as a space for the capacitor disk. Since in the prior art the separate connection wires were always extended in parallel to the collector wires, this diameter region was only restrictively available.
According to a further embodiment, it is provided that the collector wires are accumulated such that they form the collector sleeve with one section and a connection star with another section joined thereto, wherein the connection star is set onto the capacitor disk. A star of this kind may have any radial configuration so that it can be adapted in any manner whatever to the contact pads of the capacitor disk.
A further advantage is that the capacitor disk is set onto a rear side of the connection star pointing away from the collector sleeve. This has the advantage that the collector wires at the front side may be connected to the winding and the capacitor disk can be arranged within the space enclosed by the winding. Moreover, in such an embodiment the capacitor disk can more easily be connected to the connection wires for the electric connection to the winding, since the entire section of the connection star connected to the capacitor disk can be used.
In order to create a possibly stable and sufficiently precisely positioned connection star, the free ends of the legs of the connection star formed by the individual collector wires can be held by the collector plate. Since the collector wires are usually very filigree in small electromotors, an additional safety means may protect the wires from being accidentally folded at their free ends.
It is preferred in accordance with a further embodiment that the collector plate has an annular recess arranged coaxially with respect to the shaft, into which the annular capacitor disk is inserted. Through this the capacitor disk is completely integrated into the collector plate so that a space-saving arrangement is created. Moreover, the collector plate offers the opportunity of a precise positioning by a respective precise configuration of the annular groove to align the capacitor disk by similar measures at the collector plate.
The collector wires may comprise a leg extending substantially in parallel to the shaft, said leg being part of the collector sleeve, and a leg extending substantially perpendicular thereto, said leg being part of the connection star. Through this the collector wires have an L-shape, which is very simple to manufacture and enables the accumulation to a collector sleeve by a relatively simple arrangement and which at the same time enables the formation of the connection star. The perpendicularly extending leg then points radially outwardly thus causing the spacings between these perpendicular legs to enlarge towards the outside and thus providing a sufficient insulation between these legs.
In an advantageous manner it can further be provided that the collector sleeve is arranged on the front side and the recess is arranged on the rear side of the collector plate, wherein the connection star extends into the recess. Through this the advantages can be achieved in combination with the configuration of the collector plate that the capacitor disk is arranged within the space enclosed by the winding, wherein the collector wires are held by the collector plate in a manner that a direct contact of the capacitor disk with the collector wires within the recess is directly provided.
In order to enable a favorable connection of the collector wires to the capacitor disk, access openings cutting the recess for accessing the legs of the collector wires forming the connection star can be arranged at the front side of the collector plate. Through this a connection method can for instance be automated, since the connection spot can directly be accessed from the front. In this connection, each collector wire can be associated with an independent access opening, which is arranged at a spacing to the outer edge of the collector plate. Through this the collector plate is divided in spokes-like manner whereby it receives a sufficient stability despite the access openings.
In an embodiment in order to ensure a sufficient alignment of the collector plate and an association of the contact portions with the collector wires, an alignment recess may be provided in the annular recess, said alignment projection engaging into an alignment recess arranged at the capacitor disk.
In an advantageous manner, the alignment projection can furthermore be arranged at a position within the recess, at which the free end portion of a collector wire section at the connection star is held by the collector plate and additionally supports the end portion, wherein the alignment recess is arranged at the outer circumference of the capacitor disk. Thus, this alignment projection fulfills two function. On the one hand the function of a better attachment and support of the free ends of the collector wires so that these wires are sufficiently supported also in case of influence of certain forces, e.g. when connecting the collector wires to the capacitor disk. On the other hand the construction of the capacitor disk is simplified through this, since the capacitor disk usually consists of ceramics and alignment recesses are very hard to manufacture. Through the arrangement of the alignment recess at the outer circumference, this recess can further be manufactured in a simple manner.
It is a further advantage in an alternative embodiment that each free end portion of a collector wire section at the connection terminals is assigned an alignment projection and that the capacitor disk has respectively many alignment recesses. Through this a regular support throughout the entire connection region is provided.
In a favorable manner, the collector plate can be made of plastic injection-molding and the collector wires may at least be partially embedded in the plastic mass. In particular in the manufacture of smaller electromotors, this manufacturing alternative proved to be advantageous, since the collector wires are merely introduced into the mold and form a direct compound with the collector plate by injecting the plastic. Moreover, any configuration of the collector plate and adaptation to the collector wires and the capacitor disk can be implemented by plastic injection-molding.
Embodiments turned out to be especially advantageous in which the collector wires are joined with the contact pads of the capacitor disk by a conductive auxiliary material, in particular solder, solder paste and/or solder glue. The application of such a conductive auxiliary material can be automated very easily and in particular in the alternative in which access openings accessible from the front are arranged at the collector plate, a simplification of the attachment process can be achieved without great effort.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention are described in detail with reference to the drawings.
FIG. 1 shows a first alternative of a rotor for a DC electromotor according to the invention,
FIG. 2 shows the collector plate with collector wires and an arranged shaft in cross section,
FIG. 3 shows the structure of FIG. 2 in a front view,
FIG. 4 shows an access opening of the collector plate in an enlarged view,
FIG. 5 shows a capacitor disk in an enlarged front view,
FIG. 6 shows the capacitor disk of FIG. 5 in half section,
FIG. 7 shows a second embodiment of a rotor for a DC electromotor according to the invention in full section,
FIG. 8 shows the collector plate with collector wires and the shaft of FIG. 7 in an enlarged view, and
FIG. 9 shows the structure of FIG. 8 in a front view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a cage-less rotor 1 for a DC electromotor. The rotor 1 is rotatably arranged in a housing (not shown) having an iron yoke and an internally arranged permanent magnet, said rotor being arranged coaxially to the shaft 2. A plastic collector plate 3 is attached at one end of the shaft 2, with a sleeve-like rotor winding 5 being attached coaxially with respect to the shaft 2 on the cylindrical outer circumferential portion 4 of the collector plate (also see FIGS. 2 to 4). The collector plate 3 comprises a substantially cylindrical projection 6 protruding over the rotor winding 5, with legs 8 of the collector wires extending in parallel to the shaft axis being embedded in said projection. The collector wires 7 also comprise another leg 9 arranged perpendicular with respect to the leg 8, said another leg 9 extending from the shaft axis radially outwards. Through this each collector wire 7 has an approximate L-shape in side view.
In the embodiment shown, seven collector wires 7 are evenly distributed at the collector plate 3 in this manner. The parallel legs 8 of the collector wires 7 are embedded into the projection 6 in a manner that the upper side 10 thereof is exposed towards the outside, so that appropriate brushes can be set thereon. The parallel legs 8 of the collector wires 7 therefore form a collector sleeve 11. FIG. 3 also shows that the cross section of the collector wires 7 is substantially trapezoidal, wherein the longer side points towards the outside and defines the outer side 10. The shorter side is fixedly embedded into the projection 6.
Each collector wire 7 extends over the projection 6 into the central portion 12 of the collector plate 3 in which the wires are fully encompassed by plastics. In this central portion 12 the transition of the collector wires 7 from the parallel leg 8 into the vertical leg 9 is also located. The collector plate 3 has a cylindrical shoulder 13 having an accommodation bore, into which a knurled section 14 of the shaft 2 is pressed-in. Through this a connection fixed for co-rotation between the collector plate 3 and the shaft 2 is achieved. The section 15 of the collector plate 3 leading radially towards the outer circumferential portion 4 has a front side 16 pointing away from the rotor winding 5 and a rear side 17 pointing in the direction of the rotor winding 5. An annular recess 18 is formed in the rear side 17 at a distance to the outer circumferential portion 4 and to the cylindrical shoulder 13, said recess being arranged coaxially with respect to the shaft axis. The cross section of the recess 18 is substantially rectangular. The perpendicular legs 9 of the collector wires 7 extend into the bottom 19 of the recess 18, so that the rear sides 20 of the collector wires are arranged as contact pads in the recess 18.
An annular capacitor disk 21 (see FIGS. 5 and 6) is arranged in this recess 18. The capacitor disk 21 consists of a special ceramics and comprises contact pads 22 separated from one another. These contact pads 22 are obtained by silver-plating the surface of the capacitor disk 21. The contact pads 22 are separated from one another by free strips 23. The arrangement of the capacitor disk 21 in the recess 18 (see FIG. 1) is provided such that the contact pads 22 contact the rear side 22 of the associated collector wires 7.
In order to optimally arrange and align the capacitor disk 21 in the recess 18, ramp-shaped alignment projections 24 are regularly provided on the outer wall 23 of the recess 18. The alignment projections 24 are always arranged directly adjacent the free ends 9' of the collector wires 7, since in this portion a material accumulation is produced. On its outer circumference 25 the capacitor disk 21 has alignment recesses 26 distributed regularly and adapted to the shape of the alignment projections 24. The capacitor disk 21 is inserted into the recess 18 in such a manner that the alignment projections 24 precisely inserted into the alignment recesses 26 in the capacitor disk 21.
The collector plate 3 moreover comprises access openings 27 on the front side 16 which are open towards the recess 18, said access openings being designed such that seen from the front side 1, the perpendicular legs 9 and the contact pads 22 of the capacitor disk 21 are visible and accessible. In the embodiment shown, the access opening 27 extends from the central portion 12 radially outwardly to approximately the position at which the free end 9' of the collector wires 7 is embedded into the collector plate 3. Only as much material remains that ensures a safe fixing of the free end 9'. Moreover, the access opening 27 is slightly enlarged laterally, which leads to advantages for the joining technique between the capacitor disk 21 and the collector plate 7. Spokes remain between the individual access openings 27, said spokes connecting the central portion 12 to the outer circumferential portion 4.
The fixed connection between the perpendicular leg 9 of the collector wires 7 and the contact pads 22 of the capacitor disk 1 can be achieved in different manners, e.g. by solder, solder paste or conductive glue.
In the embodiment described, this joining material may be introduced through the access opening 27 from the front side 6 of the collector plate 3. Through this the joining technique is greatly facilitated, since the capacitor disk 21 is merely inserted from the rear side 17 and the connection can be established from the front side by using the respective joining material.
It is in particular evident from FIG. 3 that the arrangement of the perpendicular legs 9 of the collector wires 7 forms a kind of star shape, so that it can be referred to as a connection star, the connection surfaces formed by the rear sides of the perpendicular legs being aligned in parallel to the contact pads 22 of the capacitor disk 21, so that the capacitor disk is merely put onto this surface and then has to be joined by means of an auxiliary material. It would also be conceivable that a mere press-on is implemented if the capacitor disk 21 is fixed appropriately.
It is also evident from FIG. 1 that a connection between the collector wires 7 and the rotor winding 5 is established through respective connection wires 29. Through this the capacitor disk 21 is at the same time connected to the rotor winding 5.
The effect and function of the present invention will now be described more specifically.
By the fact that the capacitor disk 1 can be easily inserted into the recess 18 and is very easily aligned through the alignment recess 26 along with the alignment projections 24, a direct contact between the rear side 9 of the collector wires 7 and the contact pads 22 of the capacitor disk takes place. By introducing a joining material through the access opening 27, a fixed connection between the collector wires 7 and the capacitor disk 21 is produced. This process has severe advantages over the formerly used joining techniques of the prior art, since it is substantially more easy to carry out and is based on a less expensive construction.
Due to the fact that the capacitor disk 21 is located substantially within the diameter portion covered by the collector wires, this joining technique only requires relatively few space. That means that the free ends 9' of the collector wires define a diameter that is larger than the outer diameter of the capacitor disk 21. This in turn leads to the consequence that rotors 1 having extremely small diameters can be manufactured, which in turn leads to electromotors having small diameters. Up to now DC electromotors having capacitor disks 21 with diameters of less than 15 mm could not be manufactured. The present invention now even provides for embodiments of such electromotors with an even smaller diameter. The capacitor disk 21 has the advantage that the life of DC electromotors with an iron-less rotor 1 and collector is greatly increased, since less sparks are generated.
A second embodiment of the present invention is now explained with reference to FIGS. 7 to 9. In the following it is only referred to the differences to the preceding embodiment, so that the above description substantially also applies for this embodiment.
The main difference is that the shaft 2 extends through the collector plate 3 and thus through the projection 6, so that the shaft 2 is also arranged within the collector sleeve 11. Through this, a support on the shaft projection shown in FIG. 8 on the left side can for instance also take place. Except for this difference, the remaining configuration is equal to the above described embodiment. | A direct current electromotor, having in particular small dimensions, comprising a collector plate arranged on a shaft, a plurality of collector wires held by the collector plate plate and accumulated to a collector sleeve, and comprising a capacitor disk also arranged in the area of the collector plate, the contact pads of the capacitor disk are each in electrical connection to at least one associated collector wire in a respective coordination. A direct current motor of this kind shall have a more simple structure so that very small diameters can also be produced. This is achieved in that the capacitor disk with its contact pads is directly set onto the collector wires and is connected therewith. | 7 |
This is a continuation of application Ser. No. 90,109 filed on Nov. 1, 1979, which is a continuation of Ser. No. 944,795, Sept. 22, 1978, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a universal building frame principally for the load-bearing support systems of single-storey buildings of light structure, wherein the framework of the building is constituted by the combination of vertical columns and essentially horizontal beams with or without overhangs, connected to the columns and in given cases also supplementary columns, the members of the supporting system being assembled into a framework for a building on site by means of bolts of expediently identical diameter, the elements of the framework being co-ordinated as to dimension at least in the sense of the ground plan and being expediently fitted to a network based on a single basic module (m), the longitudinal dimensions of the supporting elements being integral multiples of the basic dimension of this modular network, while the loci of holes for the bolt connections are integral multiples of a micro-module (mm), derived from this modular dimension, the lower order supporting elements of the supporting system being supported on each other and/or on higher order supporting elements directly or via a connecting element, while the framework of the building is completed by a load-bearing roof plate.
2. Description of the Prior Art
Efforts to eliminate the seasonal nature of the building industry and building activity have in recent decades led to the development of so-called industrialised building methods. The essence of these methods is that in a purpose-built factory, under industrial conditions, the elements of the building are prefabricated to the greatest extent possible at high accuracy and productivity. In this way, the amount of work to be done on site can be minimised and in practice such work consists merely of assembling the fully finished elements by various erection methods.
Within this "assembled" building method, which can with justification be called industrialised, one can distinguish between a so-called heavy structure and light-structure system, as well as a system between those two, the so-called "facilitated" building system. Most of the building systems of the light-structure type are of the frame building construction which means that the load-bearing system is constituted by a metallic structure, generally of steel.
Metallic structures have relatively low own weight relative to their load-bearing capacity but this very favourable property is in many cases negated by the fact that specific investment costs significantly exceed those of concrete buildings. In addition, numerous anti-corrosion and fire-protective measures must also be carried out with such structures. For the listed reasons, the employment of light-structure metallic frame buildings can in many cases only be justified by the relative shortness of building time and the minimal labour requirement on site.
It is fundamental requirement of metallic light-structure building frames that they should be capable of being assembled from a small number of elements which should be identical as far as possible on the other hand they should be readily connectible together. The classifiability of frame systems and the industrialised nature of building methods both require that these connections should be capable of being formed in a unitary manner.
Hitherto known metallic structures for building frames have not enabled the number of profiles to be reduced nor have they enabled connections to be made in a unitary (identical) manner. In building systems throughout the world several different support types are used as elements of the frame structures. Naturally, as a consequence of this the junctions of individual support types with each other and with other support types necessitate the employment of a number of connection constructions of differing characteristics. Because of the differing locations for the junctions even in the frame systems themselves the highly desired unification could not be achieved.
With partial unification that has been achieved so far only one or two requirements made for building structures of different types have been satisfied and thus so-called "purpose-built" structures have been developed. This means that such structures cannot meet all demands for a building with an intended use or purpose differing from the original design.
SUMMARY OF THE PRESENT INVENTION
The present invention aims to provide a unitary building structure which can provide the complete frame structure of single-storey buildings or that of the top floor of multi-storey buildings to be built with a light-structure method, primarily for communal use.
An additional aim of the invention is to enable so-called assembled or prefabricated buildings to be provided in a universal structural system from simple, readily producible, erectable and exchangeably precise elements with unitary connecting constructions. The aim furthermore includes the requirement that both the constructional elements and the connections should be formed on the basis of a single modular dimension and thus the whole of the construction should become dimensionally co-ordinated while erection on site should require minimal labour.
The basis of the inventive concept is the discovery that a unitary structural construction can only satisfy the varied demands arising from the functions of the buildings if the structure is based on such a basic support type which on continuously or periodically multiplying a basic unit can satisfy the various requirements as to support span and load-bearing both as regards statics and stability.
It is also a part of the discovery that an increase in load-bearing capacity by multiplying the basic section on an "additive" principle can most simply and expediently be carried out by means of cold-shaped steel sections of C-shaped cross-section, or less frequently of U-shaped cross-section. Such a section employed by itself can be transformed into a divided section (built-up) support with another similar section placed next to it; while with a similar section placed above it, or below it, it can form a Vierendeel girder of single chord, or in given cases by doubling the divided section supports one below the other, one can obtain Vierendeel type girders of divided chord. This is because the use of identical basic sections also enables the method of connection to be the same throughout.
In accordance with the aims set out above, the universal building frame according to the invention is principally for the load-bearing support system of single-storey buildings of light structure, wherein the framework of the building is constituted by the combination of vertical columns including column elements and essentially horizontal assembly of beam elements or beams with or without overhangs connected to the columns and in given cases also supplementary columns, the members of the supporting system being assembled into a framework for a building on site by means of bolts of expediently identical diameter, the elements of the framework being co-ordinated as to dimension at least in the sense of the ground plan and being expediently fitted to a network based on a single basic module (m), the longitudinal dimensions of the supporting elements being integral multiples of the basic dimensions of this modular network, while the loci of holes for the bolt connections are integral multiples of a micro-module (mm) derived from this modular dimension, the lower order supporting elements of the supporting system being supported on each other and/or higher order supporting elements directly or via a connecting element, while the framework of the building is completed by a load-bearing roof plate, wherein the horizontal assembly of beam elements or beams supporting the horizontal or slightly curved roof plate of the building are disposed in the same or mutually parallel horizontal planes along an orthogonal network in ground plan and consisting of main beams or supports and auxiliary beams or supports wherein:
the members of the beam network or beam elements channel-shaped in transverse cross section are: solid supports of C-shaped or U-shaped cross-section, doubled C- or U-section divided section (built-up) supports formed by doubling the first-mentioned solid supports, single chord Vierendeel type girders formed by doubling the first-mentioned solid supports one below the other and, in given cases, divided chord Vierendeel type girders obtained by a combination of the latter;
the main supports or beams including two beam elements being rigidly or pivotally connected to the columns, the auxiliary supports being expediently continuous girders while the main supports are either simply supported or continuous girders at two or more places and are expediently interrupted by internal pivots of such a number as to render them statically determinate, both the main supports and the auxiliary supports being optionally provided with overhangs;
the solid supports of C- or U-shaped cross-section, the divided section supports, the single-chord Vierendeel girders and the divided chord Vierendeel girders as well as the splices for co-ordinating the chords of the Vierendeel girders being perforated with a row of holes of a configuration matching the basic module selected in the interests of full prefabricatability, precision and in given cases, of the ability to form curved or inclined roofs.
A preferred feature of the building structure lies in that the columns are clamped to the basic bodies in both principal directions of the ground plan, or they may be pivotally connected to them in both principal directions or clamped in one principal direction while pivotally connected in the other principal direction, the trunk of the columns being an I-section, for instance, of wide feet, expediently a closed tube of that shape which may, for instance, be formed by C- or U-section pairs turned with their open faces towards each other.
In the case where the support span is small, the auxiliary supports are solid C- or U-shaped supports while in the case of large span they are single chord Vierendeel girders. In the case of small span, the main supports are C- or U-shaped built-up supports, while in the case of large span they are divided chord Vierendeel girders, the splice plates of which are expediently made up of closed sections made from C- or U-shaped members turned with their open faces towards each other.
The auxiliary supports are connected to the main supports by means of channel-shaped elements or diaphragms of expediently C- or U-shaped cross-section. Where the main supports are formed as double chord Vierendeel girders, the heads of the columns are formed as the splice plates of the Vierendeel supports, expediently in the form of C- or U-sections and perforated with a row of holes.
The longitudinal dimensions of the web g, foot t and flanges or edges p of the C-profile forming the basic section of the solid supports, the built-up supports, the single-chord Vierendeel girders and the divided chord Vierendeel girders are expediently integral multiples of the micro-module (mm). The longitudinal dimensions of the web g, feet t and flanges p of the C-shaped sections forming the solid supports, the built-up supports and the chords of the Vierendeel type girders are related to each other in a predetermined manner.
The distances (e x , e y ) of the individual holes in the row of holes provided for the connecting elements are integral multiples of the micro-module (mm) both in the longitudinal direction (x) of the C-section as well as in a direction (y) perpendicular to that. In the direction (y) at right angles to the longitudinal axis (x) of the horizontal C-sections, the minimum hole spacing (y°) is one-half of the smallest hole spacing (e x ) in the longitudinal direction (x). The horizontal C-profiles are expediently divided along the bisection lines of the hole spacing (e x ) in the longitudinal direction (x) and thereby the lengths of the C-profiles themselves become integral multiples of the micro-module (mm) and thus also of the basic module (m).
The holes in the diaphragms both in the web g, and the foot t are disposed at a distance of at least one micro-module (mm) from the line of intersection of external planes of the web g and the foot t.
The dimensions and construction of the C-profiles formed as a single-chord Vierendeel girder and constituting the chords of the auxiliary supports of large span agree with those of the C-profiles formed as solid supports and constituting the small span auxiliary supports. The dimensions and construction of the C-profiles formed as divided-section Vierendeel girders and constituting the chords of the large-span main supports agree with those of the C-profiles formed as divided-section supports and constituting main supports of small span.
In an expedient embodiment of the light-structure building frame according to the invention, when the roof is not horizontal the disposition of the main supports and auxiliary supports remains the same as in the case of a horizontal roof while the inclination of the roof is imparted by diaphragms of varying heights.
The universal building frame according to the invention has numerous advantages. Most of these arise from the selection of the support type, i.e. from the circumstance that by doubling the basic section in a side-by-side or superposed arrangement, or in given cases by quadrupling it, a single basic element enables a complete building frame to be assembled for even the most varied functional requirements while affording all the load-bearing capacity likely to be encountered in practice.
The building frame can equally be used in the case of level or slightly sloping roofs. The possibility also arises of constructing a structure suitable for roof skylighting. In that case in at least every second field the roof plane can be suspended below the lower chord of the Vierendeel type main girders.
It is also advantageous that every part of the building frame, even those which are formed as Vierendeel type girders, can be erected on site from basic elements forming the basic section. Naturally, the possibility also arises of pre-erecting frameworks from columns and main supports connected thereto and lifting the whole assembly to its place in one. In addition, one can also employ high productivity erection technology such as the "lift-slab" process.
One can also mention as being one of the favourable properties of the universal building frame according to the invention that it is simple to transport it. This manifests itself in that even the divided chord Vierendeel type main girder of the largest span can, if required, be transported to site in sections. The assembly is considerably facilitated by the fact that both the supports and their connecting elements are provided with a series of holes and thus the work on site consists merely in assembling the ready-made elements and from locating and tightening the bolts.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described in greater detail by way of a preferred embodiment shown in the accompanying schematic drawings, wherein:
FIG. 1 is a ground-plan of the building frame in the case of main supports of small span,
FIG. 2 is a similar plan configuration for main supports of large span,
FIG. 3 is a section taken along the plane III--III of FIG. 1,
FIG. 4 is a section along the plane IV--IV of FIG. 2,
FIG. 5 is a section along the plane V--V of FIG. 2,
FIG. 6 is a cross-section of the C-shaped section constituting the basic section of the supports of the structural construction, and
FIG. 7 is a fragmentary perspective view of the C-shaped section indicating the perforations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the case of the embodiment of FIG. 1, the beam assembly built up from horizontal supports is constituted by main supports F and auxiliary supports M. The main supports of small span are formed as divided-section (built-up) supports of double-C-section denoted by the reference number 2. The divided section supports 2 are made up of two solid supports 1 of C-shaped cross-section which are identical and which are turned towards each other with their webs.
The auxiliary supports M also consist of two identical C-shaped solid supports 1 but these are superposed on each other and thus together constitute single chord Vierendeel girders 3. The doubling of the solid supports 1 serving as a basic section is necessitated by the large span of the auxiliary supports M. Auxiliary supports M of small span can be formed from single solid supports 1 of C-shaped cross-section also.
The chords of the single chord Vierendeel girders 3 forming the auxiliary supports M are connected by splice plates 6 at various locations and these latter are also expediently of C-shaped cross-section and form the columns of the single-chord Vierendeel girders 3. The main supports F are connected to columns 0 in such a manner that in plan view the built-up supports 2 forming the main supports F sandwich the column 0 between their "half-sections".
The cross-section of each column 0 may, if desired, be such that it fits between the half-sections of the main supports F formed as divided-section supports 2 and a connection can then be made between the column 0 and the main support F. Thus, for instance, the cross-section of the column 0 can be any I-section, expediently of wide feet, but it is more advantageous to provide a closed tubular box-girder type of cross-section which can for instance be produced by welding together C- or U-shaped sections with their open faces facing each other.
FIG. 2 shows the ground plan of a structural construction wherein the auxiliary supports M are of small span and therefore the auxiliary supports M are made up of the C-shaped solid supports 1. Therefore in this figure the splice plates for the auxiliary supports are not indicated. On this basis, the span of the supports of the main supports F are of such a magnitude that the divided section supports 2 are insufficient to take them up and instead the latter must be doubled to form divided chord or built-up Vierendeel girders 4. The divided section chords of the main supports F formed as divided chord Vierendeel girders 4 are held together and co-ordinated by splice plates 7 which are themselves expediently formed as closed tubes made up of two C-shaped sections placed open face to open face.
FIG. 3 shows the schematic cross-section of the light-structure building frame shown in FIG. 1.
The figure shows well that the main supports F are formed as divided-section supports 2 while the auxiliary supports M are formed as single-chord Vierendeel girders 3. The splice plates 6 co-ordinating the chords of the auxiliary supports M increase in height from left to right as seen, and by changing their height in a co-ordinated manner, a sloping roof T can be obtained. In this way the building frame according to the invention need not be of the flat roof type but can also be used as the frame of buildings of slightly sloping roof. It can also be observed in FIG. 3 that the end auxiliary support M at the same time serves as a cornice support extending along the longitudinal edge of the roof of the building. It can also be seen that the head of the column 0 projects between the half-sections of the main supports F formed as built-up supports 2.
FIG. 4 shows a part of the cross-section of the building shown in FIG. 2. In this case the supports F are constructed in the form of double chord Vierendeel girders 4. The splices 7 co-ordinating the chords of the double divided chord Vierendeel girders 4 are of closed section made up facing C-sections in the manner shown in FIG. 2. In this case the roof plate T is flat and thus the auxiliary supports M formed as a single chord Vierendeel girder 3 have a constant height dimension. The main supports F and the auxiliary supports M are secured together by means of diaphragms D which are also expediently of C-shaped cross-section.
FIG. 5 shows that by raising every second column space a hall construction provided with skylights can readily be constructed by the present invention. This figure also shows that the columns 0 project between the built-up chords of the divided chord Vierendeel girders 4.
The heads of the columns 0 not only serve to take load from the main supports F but also fulfil the role of splices, the so-called Vierendeel columns, which coordinate the chords of the main supports F constructed as divided section Vierendeel girders 4. The main supports F and the columns 0 are connected by a bolt connection. The heads of the columns 0 are most expediently constructed from sections of a C-shaped configuration and moreover so that the open part of the C-section should face the body or trunk of the column 0.
The diaphragms D are also capable of fulfilling several roles and expediently are also made from a C-section. In addition to connecting together the main supports F and the auxiliary supports M, the diaphragms D can play a part in creating sloping roofs, in rendering parts of the main supports rigid against bending, and moreover where the auxiliary support M is formed as a single chord Vierendeel girder 3, then the diaphragms D can also replace the splices 6.
Generally speaking, both the auxiliary supports M and the main supports F can be of continuous girder construction and may be provided with internal pivots 5 with the aid of which the individual support sections are capable of independent change of shape, are rendered mutually independent from each other i.e. can be determinate from a statical point view. The possibility also arises of provided either the main supports F or the auxiliary supports M with end overhangs.
The drawings do not show the basic bodies which can be formed in any desired manner and the columns 0 may also be connected to the basic bodies in any desired manner such as pivotally in both principal directions of the ground plan or clamped in both principal directions or pivoted in one direction and clamped in the other direction.
FIG. 6 shows on a larger scale the basic section of C-shaped cross-section forming the solid support 1. The C-shaped section is made up of three characteristic sections, namely of the web g, the feet t connected thereto and the flanges p forming projections of the feet t. By doubling the C-shaped basic section in a juxtaposed manner, one obtaines the built-up supports 2; by doubling them one below the other, one obtains the single chord Vierendeel girders 3 while by doubling the built-up supports one below the other one obtains a divided chord Vierendeel girder 5. In principle, it may be desirable to make all the horizontal supports forming the beam network of the building from identical C-shaped sections but naturally the possibility also exists of utilising different C-shaped sections e.g. from the point of view of reducing the weight, providing false ceilings etc.
The respective longitudinal dimensions h g , h t , h p of the web feet and flanges forming part of the C-sections are expediently integral multiples of the micro-module mm which itself forms an integral fraction, expediently, of the basic module m of the structural framework. According to experience, it is expedient to keep predetermined ratios between the web g, feet t and flanges p of the C-profiles. It has proved most advantageous if the section dimensions are such that h g :h t :h p =8:2:1. From the point of view of statics and stabilisation, sections have also proved to be advantageous where the relationship is h g :h t :h p =6:3:1.
It is remarked here that the dimensions of spacing of the structural framework i.e. distances between columns, between the supports, the internal wall spacings between half sections, the distribution of the splices etc. must also be integral multiples of the basic module m or the micro-module mm. In contrast, the spacing of the individual holes of the rows 8 of holes of the C-sections, prefabricated in the factory, from each other and from the end of the section are integral multiples of the micro-module mm derived from the basic module m. In FIG. 7 it can be seen that the individual holes of the rows of the holes 8 are distributed in this sense both in the longitudinal direction x of the C-profile as well as the direction y at right angles thereto.
According to experience obtained, the minimum hole spacing e x in the direction x between the holes of the row of holes 8 must be twice the minimum hole spacing e y in the direction y. The perforations forming the row of holes 8 must be at a distance of at least 1 micro-module mm from the line of intersection of the outer planes of the feet t and the web g. In addition to perforating the C-profiles forming the horizontal supports it is expedient to perforate the splices 6 and 7 and the C-sections forming the diaphragms D with rows of holes. In this way, the erection on site is genuinely reduced, apart from assembly, to placing the bolts into the holes brought into alignment and to tightening the bolts.
The structural support constituted by the solid supports 1, the divided-section supports 2, the single chord Vierendeel girders 3 and the divided chord Vierendeel girders 4 as well as their supplementary elements can be simple and productively prefabricated at the factory. Most advantageously, the C-shaped profiles can be cold-formed, thin-walled profiles. In connecting the elements in the factory, various welding methods, raw or tensioned bolted joints and optionally also metallic bonding or brazing may be used. The method of connection on site is always bolting. The identical nature of the sections and the uniformity of the connections coupled with the modularity of the system enables a high degree of automation to be effected.
The fact that the C-sections are perforated on the basis of the micro-module mm developed from the basic module m results in simply requiring the beam like supports and their connecting elements to be cut to size and thus the required construction can in practice be "delivered from stock". The complete yet unlimited co-ordination of dimensions also means that the building frame can be fitted into all known systems of building. | The invention concerns a light-structure building and a supporting frame system therefor, which can be used equally for flat or slightly inclined roofs and is built up of a single C-section support or multiples of such support. Both the supports and their supporting elements are provided with rows of holes and thus work on site consists only of making bolted connections.
The beam network of the building is constituted by main supports and auxiliary supports disposed along an orthogonal network the members of which are C-section solid supports or built-up supports obtained by doubling the solid supports in a side-by-side relationship or single-chord Vierendeel girders formed by doubling the solid supports in a superposed relationship or in given cases, divided chord Vierendeel type girders obtained by combining the latter. | 4 |
FIELD OF THE INVENTION
The invention relates to assemblies for removably mounting component trays in a rack storage system and more particularly to removably mounting fan trays more easily and efficiently without having to shut down surrounding components.
BACKGROUND OF THE INVENTION
Users of computer equipment are increasingly demanding that the equipment be easily accessible and replaceable. Often times, equipment is placed on trays to facilitate easy removal and replacement. As computer equipment often performs critical tasks, it is desirable to not have to power down the equipment to perform maintenance and replacement tasks. This ability is known as “hot-swapping,” and is a desirable feature in current systems.
The trays that are used to slidably mount the equipment must be supported by brackets that allow the trays to slide in and out of the computer racks. In the past, the brackets have been single structures extending from an upper location, down to a lower location. It is desirable not to have a large, cumbersome structure making up these brackets that takes up space, requires more material to make, and is cumbersome to use.
SUMMARY
For the foregoing reasons, there exists in the art a need for support brackets for removably mounting fan trays and other component carrying trays in a manner that enables hot swapping and promotes better efficiency. In accordance with one example embodiment of the present invention, a bracket is provided for removably mounting a tray in a component rack. The bracket has at least one guide channel extending substantially from a front end of the bracket through to a back end. The guide channel is adapted for sliding engagement with the component carrying tray. In addition, there is at least one stop guide that projects from each of the front and back ends of the bracket. This stop guide aids in positioning the bracket during bracket installation. On a backside of the bracket, (the side opposite a tray-facing side), there is a detent that projects outward from the bracket. The detent serves as an aid in positioning and releasably holding the bracket in place while the bracket is being installed. The configuration of the bracket allows it to be used as either a bottom bracket or a top bracket for mounting a tray, without having to additionally modify the bracket.
In accordance with another example embodiment of the present invention, the guide channel contained within the bracket includes at least one raised runner. The runner or runners are positioned along a base portion of the guide channel, and extend from one end of the channel to the other. They serve to decrease frictional resistance when a tray is being inserted, and also decrease static charge build-up.
In accordance with yet another example embodiment of the present invention, the bracket includes a plurality of threaded inserts embedded in each of the front and back ends of the bracket. These threaded inserts are utilized in anchoring the bracket to the tray with threaded fasteners.
In accordance with still another example embodiment of the present invention, the bracket contains a plurality of through holes. The through holes are positioned in various locations along the base of the guide channel. Fasteners are inserted through each of the holes to mount the bracket into a desired component rack.
It should be noted that other example embodiments can include a bracket having two or more guide channels. The channels in such instances run substantially parallel to each other and extend from the front end through to the back end of the bracket. Each of the guide channels include at least one raised runner following along the base of each of the channels.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned features and advantages, and other features and aspects of the present invention, will become better understood with regard to the following description and accompanying drawings, wherein:
FIG. 1 is a perspective view of a computer component rack with multiple brackets installed, according to one embodiment of the present invention.
FIG. 2 is a perspective view of a tray-facing side of a bracket according to one embodiment of the present invention;
FIG. 3 is a perspective view of a back side of the bracket according to one embodiment of the present invention;
DETAILED DESCRIPTION
In general, the present invention includes a bracket for removably mounting a tray, such as a fan tray, in a computer component rack. The bracket includes various structural aids to help in installing the bracket in the component rack. The bracket is structurally symmetrical such that a first bracket can be utilized in a bottom location and an identical copy of the first bracket can be utilized as a second bracket in a top location. Each of the brackets includes a channel along which a tray slides to ultimately be held in place by the brackets. The channels include raised runners along the base of the channel that help to reduce the frictional resistance on the trays as they are inserted, as well as reduce static charge build-up.
The present invention generally relates to a bracket 18 for removably mounting a tray 16 in a component rack 10 . The bracket 18 includes at least one (in a particular embodiment, two) guide channels 20 . Most often, the bracket 18 is mounted in two locations, one at either end (e.g., top and bottom interior walls) of a compartment 12 in which it is desirable for a computer component tray 16 to be slidably mounted. The bracket 18 is designed to fit in opposite positions to other like brackets 18 within a compartment 12 with a mere flip and/or rotation for proper orientation at installation, but without any further modifications. The guide channels 20 include raised runners 22 , which reduce frictional resistance during the insertion of a tray 16 into the bracket 18 , and also cut down on static charge build-up. The guide channels 20 support a component carrying tray 16 after being slid into the brackets 18 , and promote the installation and removal of a computer component tray 16 into a component rack 10 with greater efficiency and ease of use.
Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, FIGS. 1-3 illustrate example embodiments of a bracket 18 for removably mounting a tray 16 in a component rack 10 according to the present invention. Although the present invention will be described with reference to the example embodiments illustrated in the figures, it should be noted that the present invention can be embodied in many alternative forms. In addition, any suitable size, shape, or type of elements or materials can be utilized.
In general, the computer component rack 10 , is a large rectangular structure. The rack shown in FIG. 1 is merely an example of the type of structure or framework in which the present invention bracket 18 may be installed. Typically, each component rack 10 includes within it several compartments 12 . These compartments 12 , provide space for the mounting of various component trays 16 containing within them various components 14 . Each component 14 can be computer-related hardware, a fan, a group of fans, a data storage device, or other electronic media.
According to one embodiment of the present invention a fan assembly 17 makes up the particular component 14 within the component tray 16 . Fan assembly 17 mounts within component tray 16 , which is removably mountable within a compartment 12 of the component rack 10 by means of mounting brackets 18 . The brackets 18 are mounted within component rack 10 in a manner that will be further discussed at a later point herein.
The brackets 18 discussed herein can be used to mount fan assemblies 17 or other types of components and component trays. However, the present invention works particularly well with the fan assembly 17 illustrated herein. Further, the fan assembly 17 illustrated shows two fans. However, the fan assembly can include any number of fans or other components and the fans or components can have alternate designs or configurations, as desired.
In a broadest sense of the invention, only one bracket 18 is necessary to support a component tray 16 . When only one bracket 18 is used, the bracket 18 installs in a compartment 12 of a component rack 10 in a bottom location, tray-side facing where the component tray 16 will ultimately be inserted, such that the component tray 16 can slide into the guide channel 20 and be held in place.
However, the component tray 16 is better supported if two brackets 18 a, 18 b are utilized in conjunction with each other. In such an instance, a first bracket 18 a mounts in the bottom location of the compartment 12 . Subsequently, a second bracket 18 b mounts in a top location of compartment 12 . The bracket 18 b is identical in shape, configuration, and structure to the first bracket 18 a mounted in the bottom location. However, the second bracket 18 b is flipped, such that the tray side again faces the direction of where the component tray 16 will ultimately be inserted, causing the channels 20 to face an interior of the compartment 12 . A detent 32 (see FIG. 3) is useful in the installation of the bracket 18 in several instances, especially in the top location bracket 18 b as will be discussed at a later point herein.
It should be noted that the installation illustrated herein shows bottom and top brackets 18 a , 18 b , but the installation can position a bracket 18 on each of a left interior wall and a right interior wall of a compartment 12 , or even front and back interior compartment 12 walls. The bracket 18 can function alone, or in conjunction with another like bracket 18 in a location opposite, and facing, the first. It does not necessarily matter where the pair of brackets 18 are positioned relative to the interior of the compartment 12 itself.
Once the top and bottom brackets 18 a , 18 b mount into the compartment 12 of the desired component rack 10 , the user may then proceed with the installation of a component tray 16 .
As illustrated in FIGS. 1 and 2, the brackets 18 each secure within the compartment 12 by means of threaded fasteners 23 , (e.g., screws), inserted into through holes 24 . Each of the through holes 24 include the feature of a recessed rim, which allows the threaded fasteners 23 to screw into the component rack 10 to a point where the heads of the threaded fasteners 23 are substantially flush with the surface of the guide channel 20 .
FIG. 2 further illustrates an isolated view of the bracket 18 according to one embodiment of the present invention. In this example, the bracket 18 includes two guide channels 20 . The number of guide channels 20 can vary depending upon the particular application or desire. The shape of the guide channels 20 can also vary. In this embodiment, the guide channels 20 are formed by three relatively planar, straight, sides. Alternatively, the sides of the guide channels can be non-planar, curved, have peaks and valleys, include surface features such as gripping detents, etc. Further, the sides do not need to be solid. The guide channel 20 surfaces can be perforated, meshed, grided, contain substantial apertures, etc. for manufacturing and performance advantages, as desired. There can also be springing clamps, or mounts, extending from a guide channel 20 surface that apply pressure and frictional force to the trays 16 to better hold them in place.
A pair of raised runners 22 follows along a base 21 of each guide channel 20 in the illustrated embodiment. The runners 22 extend from one end of each guide channel 20 to the other. In one example instance, the runners 22 had dimensions of 0.03 inches high and 0.10 inches wide. It should be noted that these runners 22 can be of greater or lesser number, and can be on other surface locations of the guide channels 20 . Further, the runners 22 can be of a different material, such as, e.g., Teflon®, metal, composite, or other plastic. These raised runners 22 serve several purposes. As the component tray 16 (e.g., fan assembly 17 ) inserts into the bracket 18 , it slides along only the surface of each raised runner 22 . This raises the component tray 16 off of the base 21 of the guide channel 20 thus reducing the risk of the component tray 16 catching on any threaded fasteners 23 that were poorly fitting fasteners or may not have been completely or properly screwed into the bracket 18 and component rack 10 . Further the raised runner 22 surface area is far less than that of the entire guide channel 20 itself. In turn, the contact surface area between the raised runners 20 and the component tray 16 is less, which provides for lower frictional resistance on the component tray 16 as it slides into the bracket 18 . A further advantage is that with less frictional resistance, there is a reduced amount of static charge build-up. Static charges can be detrimental to the types of computer components 14 stored within the trays 16 , and thus there is commonly a desire to reduce such build-ups.
The bracket 18 shown includes four through holes 24 along each guide channel 20 base 21 . When mounting the bracket 18 to the compartment 12 of the component rack 10 , often threaded, or other type, fasteners (not shown) insert into these through holes 24 to mount the bracket 18 in place. Of course, the number of through holes 24 can vary from one to a plurality. Each through hole 24 has a recessed beveled edge which makes it possible to screw a screw further down, essentially until a top most portion of the screw head is flush with the base 21 of the guide channel 20 . This reduces the risk of a tray 16 edge being caught on a fastener while sliding into the component rack 10 .
There are raised edges 26 along a front portion and a back portion of the bracket 18 . The raised edges 26 contain a plurality of ultrasonically installed threaded inserts 28 . The raised edges 26 help to inhibit a user from inserting a component tray 16 too far into each guide channel 20 . Once a component tray 16 fully inserts into the guide channel 20 , threaded fasteners 29 screw into each of the threaded inserts 28 to hold the particular component tray 16 in place. The raised edges 26 may be of almost any desired shape, length, extension, etc., and serve the same function.
As illustrated in FIG. 3, bracket 18 also includes several stop guides 30 and the detent 32 . The stop guides 30 help to position the bracket 18 upon initial installation into the compartment 12 of the component rack 10 . There are stop guides 30 on each end of the bracket 18 , which contribute to the ability of the bracket 18 to mount in a bottom location, or flip and install in a top location. The stop guides 30 illustrated are merely extensions of the base 21 of the guide channels 20 . However, the stop guides can be at any location outside of each end of the bracket 18 . Their main purpose is to interfere with a back wall of the compartment 12 in which the bracket 18 is installed, at a time when the bracket 18 is in the desired position. They can be of numerous shapes, e.g., posts, blocks, spheres, half-spheres, arms, or any other shape that will effectively signal to an installer that the bracket 18 is in the proper location upon installation.
The detent 32 is useful in releasably positioning the bracket 18 when mounted in, e.g., a top position. As shown, the detent 32 has a hook-like (e.g., an upside-down “L” shape) structure. However, the detent 32 can also vary in shape, size, and location. With regard to shape, the functionality of the detent 32 is what is desired. The detent 32 , in an example embodiment, is located on the posterior, or back side of the second bracket 18 b. This shape helps to releasably mount the top bracket in position prior to installation of the threaded fasteners through the through holes 24 . The user lines up the detent 32 with an aperture located in the top portion of the compartment 12 (see FIG. 1 ), and inserts the detent 32 through the aperture (not shown) such that the detent 32 supports the rate of the bracket 18 b in the proper position for final mounting. As an alternative to an aperture, another hook, or post, etc., can mate with the detent 32 . The threaded fasteners then screw into the through holes 24 of the bracket 18 b mounting it in place. The detent 32 allows a bracket 18 installer to “hang” the bracket 18 in an upper interior wall of a compartment 12 , holding the bracket 18 in position as fasteners are inserted to mount the bracket 18 in place. The size and location of the detent 32 rely upon the size and location of the particular aperture or hook in the compartment 12 upon which the detent 32 hangs during installation of the bracket 18 . These elements must align, when the bracket is in the proper position, to serve their purpose.
Bracket 18 is preferably made of a resilient structural plastic, such as PC/ABS plastic. Typically the bracket 18 is manufactured using a standard injection molding process. Other materials and manfucturing techniques known to one skilled in the art can be employed in producing the bracket 18 of the present invention.
Having described the apparatus of the present invention, and with reference to FIGS. 1-3, the method of guiding and removably mounting a computer component tray 16 containing a component 14 in a component rack 10 can be set forth. The method begins with the step of sliding a first edge of a component tray 16 , such as fan assembly 17 , along one of the guide channels 20 in the bottom rack 18 a . The component tray 16 then rotates upward such that a top edge of the component tray 16 comes into contact with the opposing guide channel 20 in the top bracket 18 b. If the user desires, the component tray 16 can be inserted into both brackets 18 a , 18 b , simultaneously, or into the top bracket 18 b first.
Next the user slides the component tray 16 toward the back of the compartment 12 along the guide channels 20 of the top and bottom brackets 18 a , 18 b. Once the component tray 16 reaches a back portion of the compartment 12 , and a front portion of the component tray 16 meets with the raised edges 26 , the user knows that the component tray 16 has been fully inserted. At such time, if desired, the user may insert threaded fasteners 29 through apertures on the component tray 16 and into the threaded inserts 28 along the raised edges 26 of each of the top and bottom brackets 18 a , 18 b to secure the component tray 16 in place.
Typically a plug-connector, e.g., made by Molex, Inc. (not shown), makes the electrical connection between the particular component tray 16 and the component rack 10 . The connector could be of the type, for example, serial, parallel, or USB. As the component tray 16 slides into the component rack 10 , the male and female portions of the particular plug configuration are lined up and eventually mate once the component tray 16 is fully stowed. Alternatively, a connection could be made with a cord or other extended plug independent of the stowing of the component tray 16 .
Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode for carrying out the invention. Details of the structure may vary substantially without departing from the spirit of the invention, and exclusive use of all modifications that come within the scope of the appended claims is reserved. It is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law. | A method and apparatus relating to a support bracket ( 18 ) enabling hot-swapping of component trays ( 16 ) in component racks ( 10 ) is disclosed. A bracket ( 18 ) is provided for removably mounting a tray ( 16 ) in a component rack ( 10 ). The bracket ( 18 ) has two guide channels ( 20 ) extending substantially from a front end of the bracket ( 18 ) through to a back end. The guide channel ( 20 ) is adapted for sliding engagement with the component carrying tray ( 16 ). In addition, there is at least one stop guide ( 30 ) that projects from each of the front and back ends of the bracket ( 18 ). This stop guide ( 30 ) aids in positioning the bracket ( 18 ) during installation. On a backside of the bracket ( 18 ), there is a detent ( 32 ) that projects outward. The detent ( 32 ) serves as an aid in positioning and releasably holding the bracket ( 18 ) in place during installation. The configuration of the bracket ( 18 ) allows it to be used as either a bottom bracket ( 18 ) or a top bracket ( 18 ) for mounting a tray ( 16 ), without any additional modifications. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention generally relates to an internal combustion engine in an automobile, and specifically to an electrical fuel saving device for heating, catalyzing, stabilizing, and magnetizing the fuel flowing from a fuel tank in the automobile in order to maintain fuel temperature within a predetermined range, improve fuel properties, prevent excessive fuel pressure, and enhance fuel vaporization, and the fuel is then to be delivered to the engine of the automobile for efficient combustion.
[0003] 2. Description of Prior Art
[0004] It is a well-known fact in automobile industry that hydrocarbon fuels such as gasoline and diesel are more efficiently burned for an internal combustion engine if their temperatures can be elevated and maintained within an optimum range than ambient temperatures at various weather conditions prior to intended combustion. To improve the fuel efficiency significantly, many engineers in prior arts have designed numerous devices trying to elevate the temperatures of the fuels above their ambient ones via three types of heat exchange media such as electricity, coolant, or exhaust gas in an automobile. The media of the coolant and the exhaust gas normally need the engine running for a longer time than the electricity medium especially in cold climate to release sufficient heat for the purpose of heating the fuels. Furthermore, both media may sometimes inevitably overheat the fuels to some extent so that the automobile is to be exposed to a great danger of fire or explosion should fuel leakages out of the fuel pipe of the automobile occur in an accident. The electricity seems to be the most feasible and reliable medium to elevate the fuel temperatures for the engine if it is not to cause substantial burden on the battery of the automobile.
[0005] Although many heating devices of the prior arts have proved to be operationally efficient in fuel saving for engines of automobiles, these devices definitely have attendant disadvantages in accompanying with the mere advantage of the fuel efficiency. The disadvantages, namely expensive price, bulky size, difficult installation, complex design, hard replacement, and unsafe use, apparently do not thus far justify for their widespread adoptions or usages by either automobile manufacturers or general public.
OBJECTS OF THE INVENTION
[0006] It is a main object of the present invention to provide an improved fuel heating device for an internal combustion engine in an automobile which is efficient in operation, inexpensive in price, compact in size, safe in use, easy in installation, simple in replacement, etc.
[0007] It is a further object of the present invention to provide a fuel heating device for the engine which can be readily retrofitted on all types and models of automobiles.
[0008] It is a further object of the present invention to provide a fuel heating device for the engine which is capable of accurately maintaining the temperature of the fuel to be delivered to a carburetor or a fuel injector in the automobile within a predetermined range below the boiling point of the fuel but substantially above the ambient temperature at various weather conditions.
[0009] It is a further object of the present invention to provide a fuel heating device for the engine which includes a built-in fuel stabilizer capable of regulating the flow and the pressure of the fuel to prevent both from reaching to an excessive or even harmful level.
[0010] It is a further object of the present invention to provide a fuel heating device for the engine which includes a built-in fuel magnetizer capable of magnetizing the fuel and improving its properties to prolong engine life, enhance fuel efficiency, and reduce deterioration of fuel delivery parts.
[0011] It is a further object of the present invention to provide a fuel heating device, which can be disposed at any convenient position for the fuel pipe between a fuel tank and the carburetor or fuel injector in the automobile, and be utilized by the engine without any alteration or modification to the original design of the automobile.
[0012] The invention will be further understood and additional objects and advantages will become apparent from a consideration of the ensuing description and drawings.
SUMMARY OF THE INVENTION
[0013] This invention relates to a fuel heating device in which a housing means defines an inlet end, inner chamber, and outlet end to allow the fuel from a fuel tank in an automobile to be heated and treated, and then be delivered to an internal combustion engine for efficient burning.
[0014] In the center portion of the inner chamber, there is an infrared annular member that further defines an interior passageway for some fuel passing through from the inlet end to be heated within. The annular member, made of heat retaining materials, is elongated in shape with its most part in small dimension at size near the inlet end and the remaining part in large dimension at size near the outlet end. On the outside surface of the annular member, there is sintered with a multi-metallic layer. The layer can enhance the temperature stability in the inner chamber by gradually releasing the heat of the annular member slowly. Wrapping around the outside surface of the annular member with, small size, there is a spirally electrical heating pipe that is made of heat conductive materials. Besides the aforementioned annular member and heating pipe, there are still multi-elements plates and filling metal gauzes within the inner chamber. The multi-elements plates may be disposed near the inlet end or the outlet end within the inner chamber. Both of the plates and the aforesaid layer are able to perform a catalysis process to improve the properties of the fuel by restoring the fuel back to the original stage at refinery level without bad influences of fuel additives.
[0015] Within the heating pipe, two or more sets of electrical heating elements and stuffing gauzes primarily made of magnesium oxide are provided to generate and conduct sufficient heat to elevate and maintain the temperatures of three thermal exchangers: namely, the heating pipe, the annular member, and the filling gauzes. On the outer surface of the heating pipe, there is sprayed with a nanometer-level ceramic coating to prevent the fuel in direct contact with the surface from overheating. A thermocouple probe is furnished at an advantageous junction of the outlet end within the device to detect the ever-changing fuel temperature. The thermocouple probe is further connected to an integrated circuit and a semiconductor controller on an electrical circuit board. The two electronic instruments are the most important components of the electrical system for the device. The electrical system is able to activate, adjust, and interrupt the electrical current from the battery to the heating elements to prevent the fuel from overheating and unsafe incidents from happening.
[0016] A fuel stabilizer, disposed against the inner wall of the inlet end, able to regulate the amount and the pressure of the fuel flowing from the fuel tank in the automobile to a constantly balancing level upon its entering into the device is supplied. A fuel magnetizer, disposed against the inner wall of the outlet end, able to magnetize the fuel for the purpose of vaporization enhancement prior to its exiting out the device is also supplied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Additional objectives, features, and advantages of the present invention will be apparent from the following detailed description and appended claims in conjunction with accompanying drawings, and like reference numerals designate like parts and elements throughout all figures in the drawings, wherein
[0018] FIG. 1 is a sectional view of a fuel saving heater showing all principal parts in accordance with the present invention.
[0019] FIG. 2 is a sectional view of a fuel stabilizer showing all principal parts in accordance with the present invention.
[0020] FIG. 3 is an outline of an electrical system in accordance with the present invention.
[0021] FIG. 4 are sectional and perspective views of two different embodiments for a fuel magnetizer and its two principal parts—an inner cylindrical magnetic member and an outer cylindrical magnetic member—in accordance with the present invention.
[0022] FIG. 5 are three exploded views of one principal part—a tubular sleeve—for the preferred embodiment of the fuel magnetizer.
[0023] FIG. 6 are three exploded views of three principal parts—the inner cylindrical magnetic member, the outer cylindrical magnetic member, and a spacer ring—for the preferred embodiment of the fuel magnetizer
[0024] FIG. 7 are orthogonal views of the fuel magnetizer in accordance with the present invention.
[0025] FIG. 8 are orthogonal views for the alternative embodiment of the fuel magnetizer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] With particular reference to FIG. 1 , a fuel heating device 10 in accordance with the preferred embodiment of the present invention comprises of an elongated housing means 12 with an inlet end 13 at its one side and an outlet end 14 at its other side, and a holding base 40 beneath it. The device may be installed on any convenient position in an automobile preferably as close to the internal combustion engine (not shown) of the automobile as possible. The housing means 12 further defines an inner chamber 15 along with the inlet end 13 and the outlet end 14 for establishing a fuel flow path from a fuel tank (not shown) to the engine with the device 10 in between. There is an infrared annular member 30 disposed in the center portion of the inner chamber 15 between the inlet end 13 and the outlet end 14 . The annular member 30 elongated in shape can be divided into two different parts. The large part is in small dimension at size 30 A with its one side situated near the inlet end 13 . The small part is in large dimension at size 30 B with its one side situated near the outlet end 14 . The annular member 30 , made of heat retaining materials, further defines an interior passageway 16 for the fuel passing through it to be elevated in temperature. The housing means 12 mounted on the round base 40 is furthermore fixed securely by a plurality of installation holes 41 on any convenient position between the fuel tank and the engine by means of fastening means (not shown) like screws or bolts. An electrical system has two very important electronic instruments, a semiconductor controller 56 and an integrated circuit 57 , and both are mounted on an electrical circuit board 55 on the base 40 . The electrical system is able to provide the device 10 with the necessary electrical energy from the battery (not shown) of the automobile.
[0027] Wrapping closely and snugly around the outside surface of the annular member 30 with small size 30 A, there is a spirally electrical heating pipe 20 . The heating pipe 20 , made of heat conductive materials, enters into the housing means 12 from an entering position 21 A near the inlet end 13 and exits out the housing means 12 from an exiting position 21 B near the outlet end 14 . The major purpose for the heating pipe 20 to wrap around the annular member 30 spirally in the inner chamber 15 is to provide intended thermal conduction from the heating pipe 20 to the annular member 30 . The minor purpose to wrap around the annular member 30 spirally is to hold the annular member 30 in a stable position within the inner chamber 15 . Both of the entering position 21 A and the exiting position 21 B of the heating pipe 20 are fixed and sealed firmly with the housing means 12 by threaded engagements (not shown) to prevent unnecessary fuel leakages. Two or more sets of electrical heating elements 50 , made of positive temperature coefficient of resistance materials and regulated by the controller 56 on the circuit board 55 , are disposed within the heating pipe 20 . Both the heating elements 50 and the controller 56 are connected with the battery to deliver the electrical energy activated by an ignition switch (not shown) of the automobile to the device 10 . All sets of the heating elements 50 are adjoined and insulated each other and/or one another all the time within the heating pipe 20 to safely ensure thermal conduction to the outer surface of the heating pipe 20 evenly, uniformly, constantly, and/or continually.
[0028] With particular reference to FIGS. 1 and 3 , when the ignition switch of the automobile is turned on, a thermocouple probe 51 with two conductor wires enclosed within a sheath (not shown) at an advantageous junction 19 of the outlet end 14 starts to constantly detect the ever-changing temperature of the fuel. There are three main reasons to explain why the temperature of the fuel is ever-changing: the extent of heat generated from the heating elements 50 , the extent of heat absorbed by the fuel from thermal exchangers like the heating pipe 20 and the annular member 30 , and flow paths of the fuel within the inner chamber 15 . There are two flow paths as the fuel enters into the device 10 , travels through the inner chamber 15 , and exits out the device 10 . For both paths, the fuel enters into the device 10 from the inlet end 13 and exits out the device 10 from the outlet end 14 . The difference between the two flow paths is the way of how the fuel travels through the inner chamber 15 . For one path, the fuel travels through the inner chamber 15 via the interior passageway 16 of the annular member 30 . For another path, the fuel travels through the inner chamber 15 via the annular hollow 18 between the annular member 30 and the inner wall of the housing means 12 . For the latter fuel, which can be moreover subdivided into the fuel with different directions due to the shape of annular hollow 18 , may carry various temperatures because of different extent of heat absorption from thermal conduction. At the area 58 between the annular member 30 and the outlet end 14 , all fuel with various temperatures and from different directions converge and blend together to develop into a steady fuel with a specific temperature at any mixing moment. By strategically selecting the advantageous junction 19 at the outlet end 14 to measure the specific temperature of the steady fuel, any wise person may appreciate the measured temperature should rightfully represent the true temperature of the fuel. According to this reasoning, the device 10 intelligently adopts the measured temperature of the fuel at the advantageous junction 19 of the outlet end 14 as the true temperature of the fuel—the yardstick to adequately activate or deactivate the heating elements 50 .
[0029] The probe 51 often detects a lower fuel temperature at ambient surroundings especially in cold weather than the temperature range predetermined by the optimum combustion for the engine. The probe 51 then converts the true temperature of the fuel into an electronic signal to be sent to the integrated circuit 57 . The device 10 under the instruction of the controller 56 is to activate the electrical current throughout all sets of the heating elements 50 in order to elevate the fuel temperature swiftly. As soon as the probe 51 detects any true temperature of the fuel reaching one degree Fahrenheit above the preset optimum range, the device 10 under the instruction of the controller 56 is to deactivate the electrical current throughout all sets of the heating elements 50 except one set to prevent the fuel from overheating. This only set of the heating elements 50 A not interrupted by the controller 56 has been continuously working to maintain the fuel temperature within the preset optimum range so long as the engine is turned on. As soon as the probe 51 detects any true temperature of the fuel dropping one degree Fahrenheit below the preset optimum range, the device 10 under the instruction of the controller 56 is to activate the electrical current throughout all other sets of the heating elements 50 B to elevate the fuel temperature again. The probe 51 , the integrated circuit 57 , the controller 56 , and the heating elements 50 all work together to constantly and/or continually activate, adjust, or deactivate the electrical current from the battery to an accurate extent in accordance with the true temperature of the fuel detected by the probe 51 .
[0030] Besides the space occupied by the heating elements 50 , there are filled with thermally conductive, electrically insulating stuffing gauzes (not shown) within the heating pipe 20 . The stuffing gauzes primarily made of magnesium oxide can hold all sets of the heating elements 50 in firm and stable positions. The stuffing gauzes virtually serve two purposes: one for a thermal conduction medium between the heating elements 50 and the heating pipe 20 and another for electrical insulation among all sets of the heating elements 50 . On the outer surface of the heating pipe 20 , there is sprayed with a nanometer-level ceramic coating 22 to prevent the fuel in direct contact with the surface from overheating. The ceramic coating 22 practically works to lessen the extent of thermal conduction between the heating pipe 20 and the fuel touching the outer surface for safety concerns. On the outside surface of the annular member 30 , there is sintered with a multi-metallic layer 32 . The layer 32 can enhance the temperature stability in the inner chamber 15 by gradually releasing the heat of the annular member 30 little by little. The layer 32 also can activate a catalysis process of restoring the fuel back to the original stage at refinery level for efficient combustion before delivery to customers. The reason for the catalysis process to improve the combustion efficiency of the fuel is that all refineries usually add additives to the fuel for numerous reasons like safety, logistics, or antifreeze. Unfortunately, these additives are not helpful or even harmful for the fuel to be burned efficiently in the engine. To further improve the properties of the fuel upon its initial entry into and final exit out the device 10 , a plurality of multi-elements plates 38 , made of catalysis materials used often by refineries, may be disposed within the inner chamber 15 near the inlet end 13 or the outlet end 14 . Likewise to the stuffing gauzes filled within the heating pipe 20 besides the heating elements 50 , there are filling metal gauzes 36 stuffed within the inner chamber 15 besides the annular member 30 , the heating pipe 20 , and the multi-elements plates 38 . The filling gauzes 36 not only can absorb the heat diffused from the heating pipe 20 and the annular member 30 to elevate the fuel temperature by means of direct contract, but also can hold the annular member 30 in a stable position within the inner chamber 15 .
[0031] With particular reference to FIG. 2 , a fuel stabilizer 60 to regulate the flow and the pressure of the fuel to a constantly balancing level comprises a cup-shaped inner casing means 61 and a cup-shaped outer casing means 62 . Both are made of stiff materials and disposed against the inner wall of the inlet end 13 for the device 10 . The cup-shaped inner and outer casing means 61 , 62 are clamped 63 together to form an enclosure 64 . The inner casing means 61 further has an inlet orifice 65 in its center portion to allow the fuel from the fuel tank to enter into the stabilizer 60 . The outer casing means 62 further has a plurality of outlet apertures 68 in its center portion to allow the fuel passing through from the enclosure 64 to enter into the inner chamber 15 of the device 10 .
[0032] In the enclosure 64 , there is a u-shaped large piston 70 whose bottom portion is close and parallel to the inner wall of the inner casing means 61 . The large piston 70 has a plurality of inlet apertures 66 in its center portion to allow the fuel passing through from the inlet orifice 65 to enter into the enclosure 64 furthermore. In the meanwhile, these inlet apertures 66 may deny some of the fuel passing through from the inlet orifice 65 to enter into the enclosure 64 furthermore when the large piston 70 is moving toward the inner casing means 61 to block some of the inlet apertures 66 . There is a large compression spring 74 disposed and extended between the large piston 70 and the outer casing means 62 in the enclosure 64 . Its one side is attached to the inner wall of the large piston 70 , whereas its other side to the inner wall of the outer casing means 62 . The compression spring 74 is to provide a restraining force to push the large piston 70 toward the inner casing means 61 and then to block the flow of some fuel from the inlet orifice 65 to enter into the enclosure 64 furthermore.
[0033] There is also a u-shaped small piston 72 disposed in the pocket of the large piston 70 in the enclosure 64 . The bottom portion of the small piston 72 is close and parallel to the bottom portion of the large piston 70 . There is a small tension spring 76 disposed and extended between the small piston 72 and the outer casing means 62 in the enclosure 64 . Its one side is attached to the inner wall of the outer casing means 62 , whereas other side to the inner wall of the small piston 72 . The tension spring 76 is to provide a restraining force to push the small piston 72 toward the large piston 70 and then to block the flow of some fuel from the inlet apertures 66 to enter into the enclosure 64 furthermore. The stabilizer 60 fully utilizes both restraining forces from the compression spring 74 and the tension spring 76 in accompanying with the moving function of large piston 70 and small piston 72 to block the flow of some fuel in order to achieve a constantly balancing level for the amount and the pressure of the fuel passing through it.
[0034] With particular reference to FIGS. 4A, 5 , 6 , 7 A, and 8 , a fuel magnetizer 80 to improve fuel properties and to enhance fuel vaporization comprises an outer cylindrical magnetic member 81 , an inner cylindrical magnetic member 82 , a tubular sleeve 83 , and a spacer ring 84 . The fuel magnetizer 80 is disposed against the inner wall of the outlet end 14 of the device 10 . With regard to the disposition, the inner magnetic member 82 is closer to the annular member 30 than the outer magnetic member 81 . Both the magnetic members 81 , 82 are made of Nd—Fe—B, whereas the tubular sleeve 83 and spacer ring 84 fuel-resistant materials. The spacer ring 84 , having four keyways 92 around its external ring surface, is disposed in the center portion of the fuel magnetizer 80 . The spacer ring 84 is to block the two magnetic members 81 , 82 and creates a cavity 85 between them. In the center portion of its internal surface, the tubular sleeve 83 has four splines 91 to insert into the respective four keyways 92 of the spacer ring 84 . Besides the center portion of its internal surface, the tubular sleeve 83 also has four splines 89 A at its one side near the outer magnetic member 81 and four splines 89 B at its other side near the inner magnetic member 82 .
[0035] The inner magnetic member 82 has five round passage holes 86 B to allow the fuel to enter into the fuel magnetizer 80 and four cylinder projections 87 B to extend into the four round passage holes 86 A of the outer magnetic member 81 . The outer magnetic member 81 has four round passage holes 86 A to allow the fuel to exit out the fuel magnetizer 80 and five cylinder projections 87 A to extend into the five round passage holes 86 B of the inner magnetic member 82 . The identical diameter of each round passage hole 86 in terms of length is exactly twice long as the identical diameter of each cylinder projection 87 for both the magnetic members 81 , 82 . Each magnetic member 81 , 82 has four keyways 90 A, 90 B around its external cylindrical surface to be inserted into by the respective four splines 89 A, 89 B of the tubular sleeve 83 correspondingly. The fuel magnetizer 80 utilizes the aforesaid splines 89 , 91 and keyways 90 , 92 to hold the tubular sleeve 83 , the spacer ring 84 , and the magnetic members 81 , 82 as a cohesive unit.
[0036] In an alternative embodiment shown in FIGS. 4B, 7B , and 8 , a fuel magnetizer 80 comprises an outer cylindrical magnetic member 81 , an inner cylindrical magnetic member 82 , and a tubular sleeve 83 . The fuel magnetizer 80 is disposed against the inner wall of the outlet end 14 of the device 10 . With regard to the disposition, the inner magnetic member 82 is closer to the annular member 30 than the outer magnetic member 81 . Both the magnetic members 81 , 82 are made of Nd—Fe—B, whereas the tubular sleeve 83 is made of fuel-resistant materials. In the center portion of its internal surface, the tubular sleeve 83 has an attached annulus 95 . The annulus 95 is to block the two magnetic members 81 , 82 and creates a cavity 85 between them. The annulus 95 is extending from the internal surface of the tubular sleeve 83 into the cavity 85 to separate the outer magnetic member 81 from the inner magnetic member 82 . Besides the center portion of its internal surface, the tubular sleeve 83 also has two splines 96 A at its one side near the outer magnetic member 81 and two splines 96 B at its other side near the inner magnetic member 82 .
[0037] The inner magnetic member 82 has five round passage holes 86 B to allow the fuel to enter into the fuel magnetizer 80 and four cylinder projections 87 B to extend into the four round passage holes 86 A of the outer magnetic member 81 . The outer magnetic member 81 has four round passage holes 86 A to allow the fuel to exit out the fuel magnetizer 80 and five cylinder projections 87 A to extend into the five round passage holes 86 B of the inner magnetic member 82 . The identical diameter of each passage hole 86 in terms of length is exactly twice long as the identical diameter of each cylinder projection 87 for both the magnetic members 81 , 82 . Each magnetic member 81 , 82 have two keyways 97 A, 97 B around its external cylindrical surface to be inserted into by the respective two splines 96 A, 96 B of the tubular sleeve 83 correspondingly. The fuel magnetizer 80 utilizes the aforesaid splines 96 A, 96 B and keyways 97 A, 97 B to hold the tubular sleeve 83 and the magnetic members 81 , 82 as a cohesive unit.
OPERATION OF THE INVENTION
[0038] The preferred embodiment of the fuel heating device 10 described and depicted above can be moreover delineated from the standpoint of its operation. When the ignition switch (not shown) of an automobile is turned on, the battery of the automobile is to provide electrical current to all sets of heating elements 50 . The heating elements 50 , made of heat resistant materials and regulated by a controller 56 , are disposed within a spirally electrical heating pipe 20 to avoid direct contact with the fuel from a fuel tank (not shown) for safety reasons. To further prevent the fuel from overheating caused by any direct contact, there is a ceramic coating 22 sprayed on the outer surface of the heating pipe 20 . The heating pipe 20 , made of heat conductive materials, enters into a housing means 12 from its one position 21 A and exits out the housing means from its other position 21 B. The heating elements 50 are to swiftly elevate the temperature of the heating pipe 20 first and then in turn to elevate ones of an infrared annular member 30 and filling metal gauzes 36 via thermal conduction within an inner chamber 15 defined by the housing means 12 . The fuel at ambient temperature furnished by a fuel pump (not shown) flows into the device 10 from an inlet end 13 . The temperature of the fuel is to be elevated by the heating pipe 20 , the annular member 30 , and the filling gauzes 36 within the inner chamber 15 by means of thermal conduction while the fuel is passing through the device 10 .
[0039] Before the fuel finally exits out the device 10 from an outlet end 14 , there is a thermocouple probe 51 to detect the ever-changing, true temperature of the fuel. Should the temperature of the fuel is above or below a preset optimum range, an electronic signal from the probe 51 is sent to an integrated circuit 57 and a semiconductor controller 56 on an electrical circuit board 55 . The device 10 under the instruction of the controller 56 on the circuit board 55 is to activate, adjust, or deactivate electrical current to all sets of the heating elements 50 except one set. This very set of the heating elements 50 A is to be continuously working to prevent the fuel temperature dropping below the preset optimum range as long as the engine is turned on. The device 10 , able to elevate and maintain the fuel temperature accurately and safely within the preset optimum range, consequently results into two favorable effects: the improvement in fuel efficiency and the reduction in emitting pollutants.
[0040] The device 10 is also able to improve the properties of the fuel furthermore by providing a multi-metallic layer 32 on the outside surface of the annular member 30 and multi-elements plates 38 within the inner chamber 15 . Both are capable of restoring the fuel back to the original stage at refinery level for the efficient combustion in the engine. The device 10 also provides a fuel stabilizer 60 to regulate the amount and the pressure of the fuel to a constantly balancing level to avoid any unnecessary fuel waste in the combustion chambers of the engine. The device 10 finally furnishes a fuel magnetizer 80 to improve fuel properties and enhance fuel vaporization by means of Nd—Fe—B permanent magnet.
[0041] Accordingly, while this invention has been described with reference to the illustrative embodiment, none should intend to interpret the description in a limiting or narrow sense regarding its scope. Various ramifications, variations, and modifications of the illustrative embodiment will be apparent to those people skilled in the art upon reference to the description. It is therefore contemplated that the appended claims and their legal equivalents will cover any aforesaid ramifications, variations, and modifications within the true scope of the invention. | A fuel saving heater, powered by electrical energy from a battery in an automobile, may be disposed at any convenient position preferably as close to the engine of the automobile as possible. The device is operative without any necessary alteration or modification to the original design of the automobile. The device has a housing means that further defines an inner chamber, inlet end, and outlet end. An infrared annular member made of heat retaining materials is disposed in the center portion of the inner chamber. A spirally electrical heating pipe, made of heat conductive materials, wraps firmly around the outside surface of the annular member. Within the heating pipe, there are not only stuffing gauzes with thermally conductive, electrically insulating nature, but also at least two sets of electrical heating elements. The heating elements are to generate sufficient heat to elevate the temperature for the heating pipe, the annular member, and filling metal gauzes stuffed within the inner chamber. All of aforesaid three thermal exchangers are then to elevate the temperature of the fuel via thermal conduction by means of direct contact. Multi-elements plates within the inner chamber are to restore the fuel back to the original stage at refinery level without bad influences of fuel additives. An electrical system including a thermocouple probe to detect the fuel temperature is to precisely control the flow of the electrical current from the battery to the heating elements. A fuel stabilizer is provided to constantly balance the amount and the pressure of the fuel in order to prevent unnecessary fuel waste for the engine. A fuel magnetizer to magnetize the fuel for the purposes of enhancing fuel vaporization and prolonging engine life is also furnished. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims the benefit of U.S. Provisional Patent Application Ser. No. 61/483,819 entitled “Telescoping Vehicle Safety Guard” filed May 9, 2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to the art of vehicle safety devices and, more particularly, to a safety device mounted beneath a body of a vehicle and including a guard portion which is supported in front on a wheel set of the vehicle, in a compliant, telescoping manner, for both deflecting animate objects from in front of the vehicle wheels and protecting the guard portion against damage by abutment of the safety guard with certain inanimate objects during operation of the vehicle.
[0004] 2. Discussion of the Prior Art
[0005] Buses are commonly employed for various transportation purposes. For instance, buses are widely employed in metropolitan mass transit systems. Unfortunately, there are inherent dangers associated with the operation of buses. Many of the most serious of these injuries are a result of individuals being run over by the bus, such as when a person slips and falls in the road adjacent a wheel of the bus and the bus crushes a limb or other body part of the individual. Correspondingly, inanimate objects can also be crushed.
[0006] To address these concerns, it has been proposed in the art to mount a safety guard directly in front of wheels on a bus to establish a safety barrier between the wheels and objects. More specifically, as represented by U.S. Pat. Nos. 5,462,324 and 5,735,560, it is known to mount a safety barrier to undercarriage structure of a vehicle, such as a bus, with the safety barrier including a lower edge extending directly along a ground surface. The safety barrier is fixedly supported at various locations, such as to axle, frame and/or suspension structure. The safety barrier is angled such that, if an object is encountered during movement of the bus, the safety barrier forces the object out from under the vehicle to a position out of the path of the vehicle wheels.
[0007] In addition to mass transit buses, school buses are widely employed in connection with transporting students for educational purposes. Of course, still other types of buses also exist. Certainly, each of these additional types of buses, as well as other types of vehicles such as those used in the trucking industry, can benefit from incorporating safety guards. Regardless of the type of vehicle to which the safety guard is mounted, serious damage can be done to the guard if the guard abuts an inanimate object, such as a curb, pole, mailbox or the like, during operation of the vehicle. Depending on the level of damage, the safety guard may not even be able to perform its desired safety function, thereby requiring replacement. Given the monetary cost and time associated with replacing of these safety guards, this scenario is undesirable.
[0008] Based on the above, there exists the need for a more feasible mounting arrangement for a vehicle underbody safety guard. In particular, there is seen to exist a need for a safety barrier mounting arrangement which will enable safety guards to be readily mounted to a wide range of vehicles in a manner which will protect the safety guard from significant damage when unintentionally abutting an inanimate object during operation of the vehicle, thereby prolonging the useful and effective life of the safety guard.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to providing a safety guard for a vehicle, such as a school or transit bus, tractor trailer or the like-type vehicle, including a frontal guard positioned at an angle in front of a wheel of the vehicle that will function to push individuals and other animate objects lying in the path of the vehicle out of the path of the wheels for safety purposes, while being mounted for telescoping movement to protect the safety guard from damage upon abutting an inanimate object during operation of the vehicle. That is, the safety guard is positioned close enough to the ground so that, if an animate object is encountered, the safety barrier will force the object out from under the vehicle and out of the wheel path, while also being mounted so as to telescope or shift inwardly of the vehicle in the event the guard engages a relatively immovable inanimate object, such as a curb, pole, mailbox or the like, during operation of the vehicle. The shifting of the frontal guard is controlled such that the guard can only move along a defined axis. In addition, the frontal guard is resiliently mounted so as to be forced to rebound back to its fully operational position after any shifting based on engaging an inanimate object. In this manner, the safety guard can still fully perform its desired safety function, yet is protected from significant, undesirable and unintended damage which could affect its performance.
[0010] Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a transit bus having mounted thereto front and rear safety guard assemblies in accordance with the invention;
[0012] FIG. 2 is an enlarged view of the mounting of the rear safety guard assembly of FIG. 1 ;
[0013] FIG. 3 is an exploded view of a safety guard mounting assembly constructed in accordance with a preferred embodiment of the invention; and
[0014] FIG. 4 is a perspective view, similar to FIG. 2 , but illustrating a permissible telescoping movement for the safety guard in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] With initial reference to FIG. 1 , a vehicle 2 , shown as a transit bus, has attached thereto, at both fore and aft regions, a safety guard 5 constructed in accordance with the present invention. In general, vehicle 2 includes a body 7 having a front end section 8 including a windshield 9 and a bumper 10 . Also provided at front end section 8 is a pair of front steerable wheels, one of which is indicated at 12 located within a wheel well 13 . Arranged directly forward of wheel 12 is a forward most side door 15 . Body 7 also includes a middle section 17 and a rear end section 19 . Supporting rear end section 19 is a pair of rear wheels, one of which is indicated at 26 arranged in a wheel well 30 created in a side panel 33 of vehicle body 7 . Also provided alongside panel 33 are various fore-to-aft spaced windows 36 which are vertically arranged below a roof 38 . Shown arranged alongside panel 33 , forward of rear wheel 26 , is a rear door 41 . In connection with describing the invention, it should be noted that safety guard 5 is arranged at a lower region 45 between wheel well 30 and rear door 41 . Safety guard 5 is actually mounted at this location beneath body 7 of vehicle 2 and is supported in front of rear wheel 26 in a compliant, telescoping manner for both deflecting inanimate objects in an operational position from in front of rear wheel 26 and protecting safety guard 5 against damage by abutment with certain inanimate objects during operation of vehicle 2 as will be detailed more fully below.
[0016] At this point, it should be noted that the invention will be described with respect to a preferred mounting of safety guard 5 to vehicle body 7 in connection with rear wheel 26 . However, safety guard 5 can actually be correspondingly mounted at a position in front of front wheel 12 as also shown in FIG. 1 . As will also become more fully evident below, the particular mounting of safety guard 5 to body 7 can greatly vary in accordance with the present invention while accommodating the compliant, telescoping configuration referenced above. In any case, with reference to the mounting of safety guard 5 in front of rear wheel 26 , FIG. 2 presents an enlarged view of lower region 45 while indicating a preferred mounting arrangement utilizing a first mounting component 47 affixed to body 7 and a second mounting component 48 affixed to safety guard 5 , with these two mounting components 47 , 48 being interconnected by a connection assembly generally indicated at 50 in FIG. 3 .
[0017] With specific reference to FIG. 3 , the underside of body 7 is indicated at 52 . First mounting component 47 includes a base 54 from which extend upstanding fore and aft side walls 56 and 57 . Base 54 is formed with a plurality of spaced slots 60 - 63 , each of which includes a first end 66 and a second end 67 . As should be evident from viewing FIG. 3 , slots 60 and 61 extend along a first axis, while slots 62 and 63 extend a second axis, with these axes being parallel to each other. Base 54 is also provided with a central, elongated slot 70 having a first end 72 and a second end 73 . Projecting from second end 73 is an upstanding flange 75 of base 54 . In the most preferred embodiment, upstanding flange 75 is formed by cutting a portion of base 54 and bending the same upward to establish the configuration shown in FIG. 3 . However, a separate upstanding flange 75 could also be readily affixed, such as through welding, to base 54 of first mounting component 47 . In any case, as shown, upstanding flange 75 is preferably formed with a through hole 76 .
[0018] As also shown in FIG. 3 , second mounting component 48 includes a main, upper plate 80 from which depends a side wall 83 that terminates in an in-turned leg 85 . Second mounting component 48 is fixedly retained by an upper body portion 90 of safety guard 5 . That is, safety guard 5 includes upper body portion 90 and a frontal guard piece 92 which is used to deflect animate objects from in front of wheels 12 and/or 26 during operation of vehicle 2 in a manner known in the art and set forth in U.S. Pat. Nos. 5,462,324 and 5,735,560, both of which are incorporated herein by reference. As the particular construction of frontal guard piece 92 is known in the art, it will not be further described herein. Instead, at this point, it should simply be realized that second mounting component 48 can be secured to upper body portion 90 in a various ways. In accordance with the most preferred form of the invention, second mounting component 48 is encapsulated in the integral molding of upper body portion 90 in a manner directly corresponding to the mounting arrangement disclosed in the '560 patent referenced above. Again, as will be more fully evident below, the particular construction and mounting of second mounting component 48 can greatly vary in accordance with the present invention such that arrangement shown in FIG. 3 is only intended to be an exemplary embodiment.
[0019] As depicted, plate 80 of second mounting component 48 includes a plurality of spaced throughholes 94 - 97 which are preferably threaded. In addition, plate 80 is also provided with a slot 99 , the formation of which aids in establishing an upstanding tab member 100 having an associated through hole 102 . When second mounting component 48 is encapsulated by safety guard 5 during manufacturing, tab member 100 extends above upper body portion 90 , holes 94 - 97 are accessible through upper body portion 90 , and both side wall 83 and leg 85 provide structural stiffness and integrity to safety guard 5 .
[0020] As indicted above, first mounting component 47 is fixedly secured to the underside 52 of body 7 . Again, the particular manner in which this attachment is performed can greatly vary in accordance with the present invention. In one preferred embodiment, upstanding side walls 56 and 57 are welded to underside 52 . More important to the present invention is the manner in which second mounting component 48 is secured to first mounting component 47 for supporting frontal guard piece 92 yet accommodating compliant, telescoping movement of safety guard 5 relative to body 7 . In particular, second mounting component 48 is positioned such that plate 80 is arranged below base 54 , while upstanding tab member 100 projects into slots 70 . At the same time, threaded holes 94 - 97 become aligned with spaced slots 60 - 63 respectively. Threaded fasteners 108 - 111 are then positioned through slots 60 - 63 and become threadably engaged to plate 80 at threaded holes 94 - 97 respectively. For this purpose, each threaded fastener 108 - 111 has associated therewith an upper washer 11 . 4 , which extends about a respective slot 60 - 63 , and a threaded end 116 which is received within a respective hole 94 - 97 of plate 80 . With this arrangement, plate 80 is secured beneath base 54 while enabling relative sliding movement between first and second mounting components 47 and 48 , with threaded fasteners 108 - 111 being movable between first end 66 and second end 67 of respective slots 60 - 63 .
[0021] Connection assembly 50 also includes an elongated threaded fastener 119 having a head 121 , a shaft 122 and a threaded end 123 . Associated with elongated threaded fastener 119 is a nut 125 . In addition, a dampening member 128 is adapted to be interposed in the connection between first mounting component 47 and second mounting component 48 . In general, dampening member 128 takes the form of a spring element, which is employed to bias upstanding tab member 100 toward first end 72 of slot 70 . In the embodiment shown, dampening member 128 takes the form of a cylindrical elastomeric block 130 having a through bore 132 . Elongated threaded fastener 119 extends through hole 76 formed in upstanding flange 75 , into through bore 132 of block 130 and finally out through hole 102 formed in tab member 100 , whereat nut 125 is threaded onto threaded end 123 to secure dampening member 128 between upstanding flange 75 and upstanding tab member 100 .
[0022] With this configuration, second mounting component 48 is permitted to shift relative to first mounting component 47 , while any shifting movement is resisted by the arrangement of dampening member 128 . In a most preferred embodiment disclosed, slot 70 is arranged parallel to slots 60 - 63 so that the relative movement will occur along the axes defined by slots 60 - 63 . In this manner, frontal guard piece 92 will assume the operational position shown in phantom at A in order to effectively deflect animate objects from in front of vehicle wheel 26 during operation of vehicle 2 while also permitting frontal guard piece 92 to be deflected in the direction of arrow C to the position shown at B in FIG. 4 if frontal guard piece 92 abuts an inanimate object with sufficient force during operation of vehicle 2 so as to prevent damage to frontal guard piece 92 . More specifically, in FIG. 4 , frontal guard piece 92 is shown to abut a raised curb 140 associated with a sidewalk 142 which has caused frontal guard piece 92 to shift in the direction of arrow C for a range defined by the length of slots 60 - 63 . In the preferred embodiment of the invention, this length is in the order of 1-½ inches (approximately 2.5-3.8 cm). Shifting of second mounting component 48 relative to first mounting component 47 will result in compression of elastomeric block 130 such that, as soon as frontal guard piece 92 becomes disengaged with curb 140 , frontal guard 92 will automatically shift back to the operational position indicated at A. By manually adjusting nut 125 , the dampening characteristics of dampening member 128 can be readily altered.
[0023] To be most effective, frontal guard piece 92 is preferably arranged extremely close to wheel 26 in its operational position, such as within about an inch or two in front of wheel 26 . To this end, the permitted shifting movement of frontal guard piece 92 upon hitting an inanimate object in accordance with the invention occurs at an angle which extends slightly forward of a transverse direction indicated at D in FIG. 4 . That is, FIG. 4 indicates a transverse direction of vehicle 2 by arrow D and a forward direction of vehicle 2 by arrow E. The desired movement between second mounting component 48 and first mounting component 47 is shown to be in a direction which at least accommodates transverse movement but which prevents movement of the second mounting component 48 , from the operational position, relative to the first mounting component 47 in a rearward direction of vehicle 2 . Of course, the farther safety guard 5 is mounted away from wheel 26 and the permitted shifting thereof limited, some rearward movement of frontal guard piece 92 could be possible. However, in accordance with the most preferred embodiments of the invention, slots 60 - 63 , as well as slot 70 , are angled slightly forward of a transverse direction D of vehicle 2 in order to most effectively provide for deflecting animate objects from in front of wheel 26 while also protecting the frontal guard piece 92 against damage by abutment of the safety guard 5 with certain inanimate objects during operation of vehicle 2 .
[0024] In connection with the embodiments disclosed, the overall safety guard is preferably formed as a one-piece unit which is mounted in front of one or more select vehicle wheels and across a portion of the underbody in the order of two feet, while having a minimal gap between the frontal safety guard and both the ground and the related wheel. The frontal guard piece can be formed of plastic, rubber, urethane, aluminum or steel, although other known materials could be used to create a physical barrier strong enough to push a child or adult from in front of the wheel. For instance, it would be possible to manufacture at least a portion of the frontal guard piece from recycled tire rubber or fiberglass. As indicated above, various mounting arrangements can be employed for the safety guard, so long as the mounting arrangements accommodate the compliant, telescoping movement described above so as to enable the safety guard to effectively deflect animate objects from in front of the wheel while also enabling the safety guard to be shifted and then automatically retracted relative to the vehicle body when a force is exerted on the safety guard by an inanimate object engaged during normal operation of the vehicle. In any case, although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from spirit thereof. In general, the invention is only intended to be limited by the scope of the following claims. | A safety guard for a vehicle, such as a school or transit bus, tractor trailer or the like-type vehicle, includes a front guard positioned at an angle in front of a wheel of the vehicle that will function to push individuals and other animate objects lying in the path of the vehicle out of the path of the wheels for safety purposes, while being mounted for telescoping movement to protect the safety guard from damage upon abutting an inanimate object during operation of the vehicle. | 1 |
FIELD OF THE INVENTION
The present invention relates to management of network services and more particularly to a method, system and program product for managing network performance by supporting generation of reliable, anticipatory alerts of potential performance violations.
BACKGROUND OF THE INVENTION
When any computer network is put into service, the network operator and the network users have their own expectations as to the level of performance to be provided by the network. Where the network operator and the network users work for the same organization, the expectations may be formalized in written memoranda or may exist only in the minds of the network users and (hopefully) the network operator.
Where the network operator and the network users work for different organizations, the expectations may be formalized in a service level agreement. A service level agreement or SLA is an agreement or contract between a service provider, the network operator, and a customer, the network user. Under a service level agreement, the customer pays a service fee in return for an assurance that it will receive network service that conforms to requirements defined by the service level agreement. If the service provider then fails to provide the agreed-to service, it ordinarily becomes subject to penalties under the agreement, such as being required to rebate at least some previously received service fees or being required to reduce fees due for future services.
While an almost infinite variety of service level agreements, both technical and non-technical in nature, are possible, the present invention generally relates to the management of network performance where performance requirements have been defined, either informally or in formal service level agreements.
Network performance requirements, whether formal or informal, should reflect the type of network service being provided and the customer's specific requirements when it uses that service. A customer with high reliability requirements may, for example, expect or even obligate the service provider to keep the network in operation for no less than a specified percentage of time. Similarly, a customer for whom network response time is critical may expect or obligate the service provider to maintain average network transit times on critical routes at or below a defined threshold.
To verify that transit time requirements are being met, the service provider can regularly have a source network station “ping” (query) a destination network station to determine round trip transit time; that is, how long it takes for the query to reach the destination and for an acknowledgment to be returned from the destination to the source.
The actual performance of the system is usually monitored by a network management application which generates a message or alert when a performance violation occurs. That alert is sent at least to the service provider to enable the service provider to take steps to restore conforming network operation. This approach, while common, has significant drawbacks for both the network user and the service provider. From the network user's perspective, the performance violation may have already caused disruptions of significant tasks or processes by the time the network user first learns of it. Even if the service provider responds promptly to a violation alert, the recovery time or time required to return to conforming network operation is necessarily prolonged since the service provider can't begin to fix a problem until the problem is known to exist. From the service provider's perspective, the service provider may already be subject to penalties under an existing service level agreement by the time it first learns of the penalty-inducing violation. Even where no formal service level agreement exists, the service provider can expect to lose customer good will for having failed to live up to the customer's expectations.
SUMMARY OF THE INVENTION
The present invention may be implemented as a method, system or program product which supports the reliable prediction of network performance violations so that a service provider receives advance warning of an impending violation and can take steps to avoid the predicted violation.
The invention can be implemented as a computer-implemented method of managing network performance where performance requirements have been established. The provided service is monitored on a recurring basis to obtain samples of actual values of a performance-defining metric. A trend in actual service is established based upon the obtained samples. Once the trend is established, the time at which the provided service will cease to meet the established performance requirements if the trend continues can be determined.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, details of a preferred embodiment of the invention may be more readily ascertained from the following detailed description when read in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic representation of a network environment in which the present invention may be implemented;
FIG. 2 is a block diagram of essential components of a network management station in which the invention may be performed;
FIG. 3 is a functional flow diagram depicting major operations which take place when the invention is used;
FIG. 4 is a plot of performance metrics over several sampling intervals;
FIG. 5 , consisting of FIGS. 5 a and 5 b , taken together, is a flowchart of essential steps performed by a method implementing the present invention;
FIG. 6 is a plot of conditions under which a pending alert can be canceled for certain successive network performance trends;
FIG. 7 is a plot of conditions under which a pending alert can be canceled according to an alternate embodiment of the invention; and
FIG. 8 is a partial flow chart showing method steps that are performed in implementing the alternate embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , the present invention is used in the administration of computer networks, one example of which is a network 10 . The network 10 is represented as including a wide area network 12 which connects local networks to remote networks (not shown). The interface between the local networks and the wide area network 12 is provided through a gateway device 14 having an attached network management workstation 16 . The illustrated local networks include both a token ring local area network (LAN) 18 and an ethernet LAN 26 . Token ring LAN is shown as having network stations 20 and 22 and a bridge 24 to the gateway device 14 . Ethernet LAN 26 is shown as including network stations 28 and 30 and a bridge 32 to the gateway device 14 .
The types of networks and network devices shown in the drawing are intended as examples of a suitable environment for the present invention. The invention can be used in virtually any multi-node network where a performance metric is measurable. The invention should in no way be considered to be limited to the illustrated environment.
Specific embodiments of the invention will be described below, but it should be kept in mind that the present invention can be implemented in several different forms, such as in special purpose hardware or in a combination of hardware and software. A typical combination of hardware and software is a general-purpose computer system using a computer program that, once loaded and executed, causes the system to carry out method steps which will be described below. The software may be pre-loaded into the general-purpose computer system or may be separately available as a computer program product which, when loaded into a computer system, causes the system to carry out the methods steps.
The term “computer program” in the present context means any expression, in any language, code, or notation, of a set of instructions intended to cause a system having information processing capability to perform a particular function either directly or after conversion to another language and/or reproduction in a different material form.
FIG. 2 illustrates the major physical components of a general-purpose computer system capable, when programmed properly, of implementing the present invention. The computer system includes a central processing unit (CPU) subsystem 34 with a processor and supporting registers, caches and logic circuits. The computer system further includes random access memory 36 , hard drive 38 and an optical drive 40 , such as a CD/R, CD/RW or DVD drive. Where the invention is implemented as a program product, it is typically made available to the network operator initially on removeable magnetic or optical media for installation onto hard drive 38 . Once the initial installation is complete, the program can be transferred into random access memory 36 as needed from hard drive 38 . Alternatively, the program may be loaded into random access memory 36 directly from an optical media mounted in optical drive 40 . The computer system further includes system input/output (I/O) adapters 42 supporting connections to standard system components such as a keyboard 44 , a pointing device 46 and a display monitor 48 . Finally, the computer system includes a network interface card 50 which provides the needed interface to the rest of the network.
FIG. 3 is a functional flow diagram illustrating major functions that are performed by a computer system programmed in accordance with the present invention. Among other tasks, the computer system functions as a network performance monitor 52 by making and/or receiving measurements reflecting actual network performance over time. The performance measurements constitute samples which are processed by a service metric sample processor function 54 to convert those samples to a metric (such as an average value) which reflects current network performance. For the sake of simplicity, the following discussion assumes that a single type of metric (average ping time) is monitored. In some situations, it may be desirable to monitor more than one type metric so that appropriate actions can be taken where any one of the metrics exceeds an allowable value.
Where successive values for a defined metric have been gathered, those values can be processed in a trend module generator 56 to determine whether there is a recognizable trend in the metric values over time. Where a metric is trending toward an unacceptable value, an alert generator function 58 can generate and send an anticipatory alert to the service provider in advance of an actual violation. The anticipatory alert gives the service provider time to take steps which will head off an actual violation of defined performance requirements.
FIG. 4 is a plot of a specific service metric over several sampling intervals. The specific service metric is ping time on a particular route between a first network station and a second network station; i.e., the time required for the first station to send a ping or query to the second station and to receive a response from the second station. Typically, the first station, which may be a network management station, is required to perform a minimum number of ping tests over a standard sampling interval 60 which, for purposes of this description, is assumed to be a 24-hour day. The actual or raw samples gathered over the course of each sampling interval can be processed to obtain an average ping value representing the average network performance over the entire day. Object 62 represents the average ping value over a first sampling interval 60 . As a matter of convention, object 62 is shown as occurring at the midpoint of the interval even though its value can't be determined until the interval has ended. To establish a trend in actual network performance, ping times are taken throughout the day and are averaged to establish the actual network performance for that day. Objects 64 and 66 represent the ping time averages for the second and third sampling intervals on the plot.
A trend in actual network performance is established by using two or more of the average ping time values and known linear regression techniques to derive a curve or line 68 representing the trend. Depending upon the service metric chosen and the network performance requirements, the trend-indicating line can be a simple straight line established using two acceptable metric averages or a curved line fitted using several successive acceptable metric averages. Assuming a straight line 68 adequately describes the trend, the slope (positive or negative) of that line indicates whether the actual network performance over time is trending toward or away from a limit 70 of acceptable network performance (maximum allowable average ping time).
A simple approach to network management would be to wait for the average ping time to exceed limit 70 before generating any sort of alert to the system provider. The present invention uses a better approach. The slope of the trend-indicating line can be calculated using two acceptable ping time averages. Once the slope of the trend-indicating line and at least one average ping time value is known, straight-forward mathematic calculations can be used to predict the time t v at which the average ping time will exceed the limit 70 if the trend continues unchanged.
In accordance with a preferred embodiment, an alert is not sent simply because a trend toward unacceptable ping times is established. For an alert to be of interest to a system provider, it must be reasonably imminent. A system provider is not likely to want to respond to a prediction of unacceptable ping times far in the future given the possibility that the trend toward unacceptable ping times might level off or be reversed in the course of normal system operation. For that reason, an alert is generated and sent to the system provider only where the predicted violation time t v falls within a time window (for example, two days) beginning at the current time. If t v is predicted as occurring outside of the time window, no alert is generated.
Even where an alert has been generated and sent to the service provider, the possibility still exists that the trend toward increasing ping time averages will level off or reverse itself in the course of normal system operation. In accordance with one feature of the invention, network performance (represented by average ping time) continues to be monitored even after an alert is generated. If the trend resulting in a pending alert is found to have changed substantially, a pending alert may be canceled.
For the described process to work reliably, the data used in the process must be reliable. In any process which relies on sampling of actual values, there is always the possibility that abnormal system conditions will result in abnormal sample values during any given sampling interval. To eliminate unreliable sets of samples, the present invention imposes reliability tests for each set of samples used in establishing a performance trend. If the reliability tests, described below, are not satisfied for a particular set of samples, the set is ignored, at least for trend determination purposes. The set of samples may be retained in the system for other purposes beyond the scope of this invention.
A first and seminal reliability test is that the number n of samples obtained over a sampling interval must exceed a predetermined minimum. Conventionally, it is assumed that at least thirty measurements or samples of a particular metric are needed to support reliable statistical analyses. If, during a particular sampling interval, less than thirty samples are obtained, no attempt is made to establish a performance trend using the sample set.
Assuming the necessary minimum number of samples have been obtained over the sampling interval, a second reliability test uses standard statistical techniques to derive the statistical mean and the statistical standard deviation of the set of samples under consideration. For a set of n samples, each having an individual raw value y i , the statistical mean is simply the average of the values; that is
y mean = ∑ y i n
For the same set of samples, the standard deviation s can be computed as
s
=
n
∑
(
y
i
)
2
-
(
∑
y
i
)
2
n
(
n
-
1
)
To determine whether a particular set of samples are reliable, the mean value y mean and the standard deviation s of the set are used to generate a Confidence Percentage value CP where
CP = y mean s
A set of samples is considered reliable (and thus suitable for use in the described process) if CP does not exceed a predetermined percentage threshold, preferably on the order of 25%. If CP exceeds the predetermined threshold, no effort is made to determine a performance trend based on the “unreliable” set of samples.
Where a set of samples gathered during a particular sampling interval is not to be used as failing to meet reliability tests, acceptable samples gathered during preceding and following sampling intervals can still be used to establish the trend in network performance.
FIG. 5 is a flowchart of method steps that are performed in implementing the present invention. The initial step 74 is to perform a system test which generates raw sample values. The ping response time test described above is just one example of many types of system tests which might be performed to obtain a measure of actual network performance. Each test 74 is followed by a time check 76 which determines whether the current sampling interval has just ended or expired. If the sampling interval has not expired, a second time check 77 is made to determine whether an inter-sample interval timer has expired.
The inter-sample interval timer is used to limit the number of samples acquired during a given sampling interval since every test operation performed to acquire a sample represents network overhead and necessarily impacts network throughput. As noted earlier, good statistical practice requires a minimum of thirty samples for statistically reliable averaging. Therefore, it can be expected that the inter-sample interval timer will have a short enough timeout period to guarantee that at least thirty samples will be obtained over the course of the sampling interval. The maximum number of samples to be obtained may vary with the type of system test being performed. For ping time tests, it is believed that a maximum of 130-150 samples per twentyfour hour sampling interval is appropriate.
When the sampling interval does expire, the number of samples obtained during the interval is compared to a minimum threshold number in operation 78 . If the number of samples falls below the minimum threshold, no effort is made to continue the trend determination process and the current process cycle is ended. Even though the current process cycle ends, a new sampling cycle is already underway for the new sampling interval that has just begun.
Assuming an adequate number of samples is obtained for the current cycle, the raw samples are summed in step 80 . In a following step 82 , each raw sample in the set is squared and the squared values are summed. The average or mean value for the set is obtained in step 84 while the standard deviation for the set is calculated in step 86 .
As described earlier, the set of samples may or may not be used depending on the confidence percentage CP for the set; that is, the ratio of the set's standard deviation to its mean or average value. The CP value is calculated in step 88 using the earlier-described equation and then compared to a predetermined threshold percentage in step 90 to determine whether the set's CP value falls within acceptable limits. If the set's CP value falls outside the acceptable limits, the trend determination process is ended without using the “unreliable” set of samples.
Assuming the set of samples under consideration satisfies the defined reliability tests, the averages or mean values for the current set and an earlier set of samples are used in an operation 94 to determine whether there is a trend in average ping response times. The trend is characterized by the slope of a line passing through the two time displaced mean values. The slope is tested in step 96 to determine whether the average ping response times are approaching a violation threshold. If step 96 shows that the trend is toward violation, the current slope of the line, one of the average ping response times at an endpoint of the line and the violation threshold are used to predict (step 98 ) when the average ping response time will exceed the threshold assuming the current trend continues unchanged.
This predicted time-until-violation value can be determined by solving the equation
y=mx+b for the value of x where
y=the maximum acceptable (violation threshold) average ping time,
m=the computed slope of the trend line during the last sampling interval,
b=the current average ping time, and
x=the time-until-violation as measured from the current time.
The variables y, m and b are known, making it a simple matter to determine x. Once the predicted violation time is established, it can be checked in an operation 100 against the limits of a time window (for example, a time window that begins at the current time and ends 48 hours later). If the predicted time of violation falls outside the time window, the current process cycle is ended with no action being taken other than to preserve the values calculated using the current set of samples. However, if the predicted time of violation falls within the time window, an alert is generated in step 102 and sent to the network manager.
If step 96 does not indicate that the current trend is toward the violation threshold, meaning the trend is either flat or away from the violation threshold, then a check 103 is made as to whether a previously generated alert is still pending. If there is no pending alert, no further computations are performed and the current process cycle is ended.
If a previously generated alert is still pending, the absolute value of the slope of the current trend line is compared to the absolute value of the slope of the preceding trend line in an operation 104 . Unless the absolute value of the new slope is greater than the absolute value of the preceding slope while the sign of the new slope is negative, the trend toward an eventual violation necessarily continues. The samples and the metric average are retained. The previously-generated alert is not affected. The current process cycle is ended to allow the next iteration of the process to continue.
If, however, the absolute value of the new slope is greater than the absolute value of the old while their algebraic signs are different, a significant trend away from the violation threshold is necessarily indicated. This can most clearly be seen by reference to FIG. 6 where line 110 represents an old or prior trend line while line 112 represents the current trend line. While the slope of line 110 shows a trend toward violation, the slope of line 112 shows an even sharper trend away from violation. Referring back to FIG. 5 , where a significant trend away from violation is found from the test 104 , the previously-generated and still pending alert is canceled in step 106 .
An alternative and less stringent test for determining when to cancel a previously generated alert is described below with reference to FIGS. 7 and 8 . The alternative test is based on a premise that a pending alert issued as a result of a prior trend can safely be canceled if an alert would not be generated based on the current trend. Recall that an alert is generated in the process described above where a trend toward a violation threshold will cross that threshold within a predetermined time window if the trend continues unchanged. A time window of two days was assumed for purposes of illustration.
Referring first to FIG. 7 , which illustrates the premise of the alternative process, an alert is generated at time t 3 because the trend characterized by line 114 would result in the violation threshold being exceeded within two days of time t 3 . However, for the current trend represented by line 118 (beginning at time t 3 and ending at time t 4 ), it can be seen that the lesser slope of the current trend would not, if continued, cause the trend to reach the violation threshold will not be exceeded within two days of time t 4 even if the trend continues unchanged. Under the noted conditions, no alert would be issued at time t 4 . If an alert would not be issued at time t 4 based on the then current trend, it would be illogical to allow a previously-generated alert to remain in force. If a determination is made that current conditions do not warrant generation of an alert at current time t 4 , then pending alerts based on past conditions are canceled.
FIG. 8 is a flow chart of the method steps required to carry out the alternative process steps noted above. The method steps previously described with reference to FIG. 5 remain unchanged from the beginning of that Figure through the output from operation 94 , which is the slope of the current trend line. In the alternative process, the determined slope is used as an input to a step 120 which determines whether the current trend is toward violation. If it isn't, any pending alerts are canceled. If the trend is found still to be toward violation, the time at which the trend will result in a violation is predicted in step 124 . If the predicted time of violation falls is found to fall within the time window in step 126 , then a new alert is generated in step 128 . Previously-generated alerts (if any) are not canceled.
If, however, the test 126 indicates that the latest predicted time of violation falls outside the time window, which means that no alert is to be generated based on current conditions, test 130 looks for previously-generated and still pending alerts. If any such alert or alerts exist, they are canceled in step 132 .
While there has been described what is believed to be a preferred embodiment of the invention, variations and modifications in the preferred embodiment will occur to those skilled in the art. Therefore, it is intended that the appended claims shall be construed to include the preferred embodiment and all variations and modifications as fall within the true spirit and scope of the invention. | A service level agreement between a network service provider and a network user may require that specified service metrics or parameters be maintained within predetermined limits. To reduce the chance those limits (and the service level agreement) will be violated, the service metric is sampled periodically over successive sampling intervals. The mean value and the standard deviation of the set of samples obtained during the most recent sampling interval are used to screen out unreliable data. If the set of samples satisfies the reliability screening, the set is used in combination with past acceptable sets to determine the trend in the sampled service metric. If the trend is toward a violation, the time of the violation is predicted based on the assumption the current trend will continue. If the predicted time of violation is sufficiently near the current time, an alert is sent to the service provider to permit the service provider to initiate anticipatory corrective action. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to plates and fasteners which are employed for securing insulation and the like to roof decks. More particularly, the present invention relates to threaded fasteners which engage stress plates for fastening insulation and like material to roof decks.
In roof systems to which the present invention relates, threaded fasteners engage metal plates or plastic plates of various configurations to secure insulation material to a metal roof deck. Plies of synthetic coating, tar, gravel or various roofing materials are then applied over the insulation to complete the roof. Most of the plates employed for such roofing applications, whether they be composed of metal or plastic, have a pre-fabricated central opening which receives the fastener. The plates have a generally planar portion for engaging the insulation along a substantial surface area. The plates are sufficiently rigid to secure the insulation to the deck under intense wind-produced lift forces which may be exerted on the roof.
Plastic and/or molded stress plates have in many instances replaced the conventional metal plates. Among a number of advancements in plate/fastener technology are improved provisions for aligning the fastener as it penetrates the insulation and metal deck, improved structures for preventing the plate from being pulled over the fastener, improved moisture repellent characteristics, and improved structures to lessen the tendency of the plate to cut or penetrate the plies of material installed over the insulation.
Both metal and plastic stress plates are susceptible to the fastener being overdriven (excessive penetration depth into the anchoring deck) resulting in an excessive load being exerted on the plate. While installation tools for driving the fasteners ordinarily employ depth setting mechanisms which are directed to prevent overdriving of the fastener, such tools require a critical depth adjustment necessitating periodic field adjustments. In a number of installation projects either no depth adjustment tool is employed and/or the installation tool is not properly adjusted for the specific roof construction.
U.S. Pat. No. 4,361,997, invented by the inventor of the present invention and entitled, "Fastener Plate and Assembly", discloses a plastic plate employed in combination with a threaded fastener to secure insulation to a metal roof deck. The plate has a planar portion with a centrally disposed tapered hub. A central bore through the hub is dimensioned to facilitate proper alignment of the fastener as it is driven through the insulation into the roof deck so that a perpendicular orientation of the fastener to the deck is maintained. The head of the fastener is seated in a counterbore of the plate below the upper surface of the plate when the proper depth is obtained, thereby clamping the insulation to the deck. In such conventional fastening systems, the installation process must be essentially completed simultaneously with substantially the seating of the fastener in the counterbore of the plate.
A disadvantage of the fastener/plate assembly, such as disclosed in U.S. Pat. No. 4,361,997, as well as other assemblies wherein the fastener seats onto or within the stress plate, is the absence of effective means for tolerating fastener overdriving which can and does frequently occur during installation. Should the fastener be overdriven, the fastener head would force the plate into the insulation, potentially developing an excessive load on the plate. For a relatively soft and yielding insulation, the increased load exerted on the plate due to overdriving may not be sufficient to cause the plate to fail. However, if the insulation is relatively rigid or non-compressible (high compressive resistance), the load could result in stress cracking of the plate. The resistance to joint loosening may also be lost in overdriving the fastener. The threads which are formed in the plate could strip out so that the fastener loosens from the plate.
Over extended time periods, vibratory forces also tend to loosen the fastener. The fastener may pop above the plate and/or the plate may transform to a "reverse umbrella" configuration. In either case, the integrity of the roofing plies is threatened. Thus, the advantages of conventional fastening systems as discussed may even be negated over time by proper driving of the fastener.
SUMMARY OF THE INVENTION
Briefly stated, the invention in a preferred form, is a fastener/plate assembly for fastening material to a roof deck. The assembly comprises a stress plate having a hub which extends generally axially from the bottom surface of the plate. The plate and hub define a central opening of pre-established diameter. A fastener comprising a driver end, a distal end and a bifurcated shank portion, includes a first thread adjacent the distal end having a maximum thread diameter which is less than the diameter of the central opening. The other shank section has a second thread with a maximum diameter greater than the first thread. The second thread is threadably engageable with the hub portion. The diameter of the driver section may be less than the diameter of the opening.
The first section is loosely insertable in the opening and the second thread is threadable through the axial extent of the hub portion. The fastener and plate are dimensioned so that by the time the distal end of the fastener engages the roof deck, the plate has provided no alignment to the fastener since the second thread has yet to threadably engage the hub portion. Upon torqueably driving the driver end, the second thread is threadably disengageable from the plate to allow the driver end to axially pass through the opening. Anti-rotational projections may depend from either the upper or lower surface of the plate to prevent rotation of the plate. The fastener includes a non-threaded section which is axially intermediate the first and second threads. The thread pitch of the first thread is not equal to the thread pitch of the second thread.
An object of the invention is to provide a new and improved plate/fastener assembly for securing insulation and like materials to a roof deck.
Another object of the invention is to provide a new and improved plate/fastener assembly which is capable of effectively accommodating an overdriven condition of the fastener without excessive loads being exerted on the plate.
A further object of the invention is to provide a new and improved plate/fastener assembly which is resistant to vibratory forces tending to prevent the fastener from loosening from the roof deck.
A further object of the invention is to provide a new and improved plate/fastener assembly which greatly reduces the susceptibility of the plate to stress cracking upon installation and from puncturing or cutting into surrounding roofing material.
Other objects and advantages of the invention will become apparent from the drawings and the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view taken through the central axis of a plate/fastener assembly in accordance with the present invention further illustrating the assembly in an installed position for fastening insulation to a roof deck;
FIG. 2 a fragmentary sectional view of the plate/fastener assembly of FIG. 1 illustrating the fastener in a pre-installation position relative to the plate;
FIG. 3 is a bottom plan view, partly in phantom, of the plate of FIG. 1;
FIG. 4 a top plan view, partly in phantom of the plate of FIG. 1;
FIG. 5 is an enlarged side elevational view of the fastener of FIG. 1, said view further illustrating dimensional relationships; and
FIG. 6 is an enlarged fragmentary side elevational view of an alternate embodiment of a fastener for the assembly of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings wherein like numerals represent like parts throughout the Figures, an installed non-seating plate/ fastener assembly, in accordance with the present invention, is generally designated by the numeral 10. Assembly 10 comprises a circular plastic stress plate 12 and a threaded fastener 14. Although not limited in its utility, the assembly is especially adapted for fastening insulation 16 to a metal roof deck 18 as best illustrated in FIG. 1. In the preferred application, a multiplicity of plate/fastener assemblies 10 are installed at spaced locations for attaching insulation board to the deck, and in certain instances for attaching membrane along the board seams. The fasteners are driven into the metal deck 18 by means of an installation tool (not illustrated).
The non-seating characteristic of the assembly refers to the relationship between the fastener and the plate wherein the fastener does not eventually assume an axially fixed seated relationship with the plate upon continuous application of a torque to the fastener regardless of the axial advance of the fastener relative to the plate. Stated differently, after the plate seats against the insulation or secured material, continued application of a torque to the fastener results in continued relative axial movement between the fastener and the plate until the fastener disengages from the plate.
The plate 12 has a top surface 20 which will ordinarily eventually be covered by plies of roofing material. The plate 12 has a bottom surface 22 which engages against the top of the insulation 16. A tapered hub 24 integrally extends from the bottom surface 22 at a central position thereof. An axial bore 26 extends through the hub. The hub portion may be exteriorly tapered to facilitate penetration into the insulation.
Anti-rotational structures which may be, for example, ribs 30, integrally project from the bottom surface and radially extend from the hub 24 to the peripheral edge 32 of the plate. The ribs 30 may be spaced every 90° around the central axis of the plate and may have an enlarged anchoring portion adjacent the hub portion and taper into a reduced convergent portion toward the outer edge 32.
Alternately, or in addition, projections which are angularly spaced for extension above the top surface 20 may be employed to prevent rotation of the plate upon installation of overlay material on the plate. Other anti-rotational structures may also be provided. However, the invention does not require any such anti-rotational structures. The top and bottom surfaces of the plate may thus also essentially be smooth surfaces.
Inclined recesses 34 in the plate may be employed for rotatably fixing the plate relative to an installation tool (not illustrated). The recesses 34 extend in perpendicular relationship and are adapted to mate with a complementary component of an installation tool.
The threaded fastener 14 longitudinally extends from a driver end 40 to a distal tapered tip 42 and includes (from driver end 40 to distal tip 42) a plate engaging thread 44, an intermediate non-threaded shank portion 46 and a deck engaging thread 48. In some embodiments, the interrupted or non-threaded shank portion is negligible. The threaded fastener 14 is specifically dimensioned in relation to the bore 26 of the stress plate 12 and can best be appreciated with reference to the dimensional relationships illustrated in the drawings (FIG. 5). The bore 26 (not illustrated in FIG. 5) has a uniform diameter X. The diameter Y of the reduced thread 48 is less than the diameter X. The diameter W of the non-threaded shank portion 46 is less than the reduced thread diameter Y. The thread diameter Z of the enlarged thread 44 is greater than the diameters W, X and Y. The maximum diameter D of the driver end 40 may be less than the corresponding diameter Z of the enlarged thread 44 as well as diameter X of the bore 26. In some embodiments the diameter D may slightly exceed diameter X. In addition, the thread pitch of the enlarged thread 44 is preferably less than or equal to the thread pitch of the reduced thread 48.
The foregoing dimensional relationships may be expressed by the following mathematical relationships:
Z>X
Y<X
W>Y
D<Z
Because of the recited dimensional features of the fastener 12 and the associated plate 14, the hub 24 does not provide any alignment properties as the fastener is initially being driven through the hub for penetration through the insulation into the roof deck. The reduced thread 48 and the non-threaded shank portion 46 are essentially freely loosely insertable through the bore 26. After the reduced thread 48 initially engages and continues to thread into the roof deck, at some pre-established depth depending upon the insulation thickness, the lead of the enlarged thread 44 will engage the top of the plate 12. The enlarged thread 44 will self-tap into the bore wall portion thereof to thereby create a threaded engagement between the fastener and the plate. The threading engagement of the enlarged thread 44 with the plate secures the plate against the insulation to essentially fasten the insulation in place and thereby resist any uplifting wind forces.
It should be appreciated that at no time does the fastener seat with the plate because the diameter D of the hex driver 40 is less than the diameter Z of the enlarged thread 44. Should the fastener be overdriven, the enlarged thread 44 will merely thread further into the plate. In the extreme instance, the enlarged thread 44 could, in theory, be threaded to a depth which entirely disengages the fastener from the plate.
Even if the driver diameter D slightly exceeds bore diameter X, the fastener driver end may axially penetrate the tapped hub and eventually completely traverse opening 26. If diameter D exceeds diameter X, the driver end 40 may distort the tapped hub portion to prevent reverse threading of the fastener. The diametral encroachment of the driver end into the hub (to the extent there is any encroachment) must be sufficiently small that the driver end does not fixably axially engage the plate to pull the plate toward the deck upon continued application of torque to the fastener. In the illustrated embodiment, driver diameter D is less than the bore diameter X, and there is no hub structure encroachment by the fastener. It should be appreciated that the severe stress loading against the plate which is characteristic of a conventional seated fastener will not occur in assembly 10. In addition, visible evidence that the fastener is overdriven will be apparent from visual inspection of the plate.
It is preferred for the described roof applications that the pitch of the enlarged thread 44 be smaller than that of the reduced thread 48. The foregoing relationship provides that for every threaded revolution into the deck, the fastener axially advances a pre-established distance, but the plate advances only a fraction of the distance. Consequently, the plate 12 would be forced to penetrate into the insulation an axial distance proportional to the ratio of the thread pitches. Stated differently, the plate 12 would be forced into the insulation an axial distance equal to the distance between the thread leads. The mismatch of the thread pitches (or leads) is functionally possible because the insulation material is not sufficiently rigid to cause any stripping in the plate.
It should be further appreciated that the thread 44 now also functions to resist the loosening of the fastener from the deck by the loosening resistance created by the threading engagement of the thread 44 and the plate 12. The vibratory forces tending to loosen the shank thread will encounter an independent resistance to loosening at the plate since there are two different thread pitches.
The thread pitch relationship between the first and second threads could be reversed for applications where quick loosening is desirable.
It should be also appreciated that the plate could be a metal plate formed by extruding a deep central opening or a composite plate wherein the steel plate has a plastic hub portion assembled into the steel plate. In addition, the specific shape of the plate is not critical. For example, the plate could be square or numerous other shapes.
The dimensions for one example of the fastener/plate assembly 10 are set forth in Table I.
TABLE I______________________________________ D .289 inch X .255 inch Y .250 inch Z .312 inch W .202 inch______________________________________
With reference to FIG. 6, an alternate embodiment of the fastener 15 differs from fastener 14 at the driver end portion. A socket 41 extends axially into the fastener top to facilitate a hex torque driver coupling with the fastener. All other dimensional relationships as described for fastener 14 are applicable to fastener 15.
While the preferred embodiments of the invention have been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention. | A fastener/plate assembly for fastening material to a roof deck employs a threaded fastener having a shank with two thread sections. The distal end portion of the shank has a thread which is loosely insertable through an opening of the plate. A second thread of the shank has a thread diameter greater than the first section and is threadably engageable with the plate. The driver end of the fastener is dimensioned so that during an overdrive condition, the fastener may threadably disengage from the plate to allow the driver end to pass through the stress plate opening. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an improved wet spinning process for fibers and more particularly to the extraction of liquid from the fibers.
In the manufacture of certain solution spun synthetic polymeric yarn, an important process step concerns extraction of the liquor material from the yarn. This is usually accomplished by either passage of the yarn bundle over rotary rolls and under water sprays or through a plurality of immersion tanks filled with water or neutralizing agents. By the latter method, it is not uncommon to utilize at least four to six tanks for maximum liquor extraction. Although the technique is highly effective, it is inherently speed limited. The yarn material must be processed through the immersion tanks at relatively slow speeds due to excessive frictional drag that tends to build up between the liquid and the bundle fibers. In addition, relatively long immersion residence time is required in order for the water or neutralizer to thoroughly wash the yarn bundle. Thus, washing low denier yarn at speeds above 500 yards per minute tends to become impractical. Finally, at the higher speeds percent liquor carry over increases steeply further reducing washing efficiency. Numerous attempts have been made to improve textile yarn washing efficiency and treatment speed but these have been limited to relatively slow process speeds since high relative velocities tend to produce frictional drag which eventually damages the product.
Accordingly, it is an object of this invention to provide a compact, highly efficient yarn wash device capable of treatment of solvent-laden yarn at high throughput rates.
Another object of the present invention is to provide a multistage solvent extraction which subjects the yarn material to substantially no tension buildup.
SUMMARY OF THE INVENTION
The present invention provides for high speed, high efficiency wash treatment of solvent-laden yarn moving through a process such as described by Blades in U.S. Pat. No. 3,767,756 and involves a yarn washing and extraction apparatus that has a body with a straight passage therethrough and throuugh which yarn passes for treatment. The passage includes a pair of extraction chambers connected by passage lengths of different cross-sectional areas. Conduits are angularly disposed into the passage for stripping liquid from the yarn before washing and final stripping by similarly disposed conduits.
More particularly, the extraction and washing apparatus includes a body having a passage extending along a straight axis therethrough and through which yarn travels for treatment, said passage including successively a first extraction chamber having means for draining the chamber, a first cylindrical length, a second cylindrical length having a greater cross-sectional area than said first length, a second extraction chamber having means for draining the chamber, said chamber being followed by a third cylindrical length equal in cross-sectional area to said first length; a first pair of conduits angularly disposed into the passage at the junction of the first extraction chamber and said first length to provide flow paths into the chamber counter-current with the yarn travel; a second pair of conduits angularly disposed into the passage at the junction between said first and second lengths to provide flow paths into the passage co-current with yarn travel; liquid supply means connected to said second pair of conduits; a third pair of conduits angularly disposed into the passage at the junction of the second extraction chamber and said third length to provide flow paths into the chamber counter-current with yarn travel; and gas supply means connected to the first and third pairs of conduits.
The invention also includes an improved method of washing and extracting liquid from a solution spun yarn between the quenching step and packaging step comprising: passing the yarn through an enclosed passage immediately following quenching step; while successively impinging opposed streams of gas against the yarn counter-current to its travel to remove quench liquid from the yarn; draining the removed quench liquid from the passage, said yarn carrying gas along said passage; impinging opposed streams of liquid against the yarn co-current to its travel, to turbulently mix said gas and said liquid to diffuse liquid into said yarn and reduce frictional drag on the yarn impinging opposed streams of gas against the yarn counter-current to its travel to remove diffused liquid from the yarn; and draining the removed diffused liquid from the passage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevation of the invention used with a wet spinning process.
FIG. 2 is a schematic illustration of the wash extraction apparatus of FIG. 1.
FIG. 3 is a schematic illustration of a pair of conduits angularly disposed into the yarn passage for extraction.
FIG. 4 is a schematic illustration of a pair of conduits angularly disposed into the yarn passage for stripping.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The wet spinning apparatus chosen for purposes of illustration is that used in the spinning process of Blades U.S. Pat. No. 3,767,756 and includes as general components thereof a transfer line 10 through which is pumped spinning dope to a spinning block 12 located above the vessel 14 containing a liquid coagulating bath 16 supplied from pipe 17. A spin tube 20 is immersed in the bath 16, extends through vessel 14 and connects to the extraction and washing apparatus generally designated as 30. Extruded filaments 13 are forwarded through coagulating liquid 16 that is flowing from vessel 14 through tube 20 into extraction washing apparatus 30 from which it is removed via drain pipe 31 with the assistance of air supplied through pipe 32. Water for washing the filaments is supplied through pipe 35 and removed via drain pipe 33 with the assistance of air supplied through pipe 34. The filaments are withdrawn from extraction wash apparatus 30 by driven roll 36 and its associated separator roll 38 and conducted under guide 37 for winding on rotating bobbin 39.
As shown in FIG. 2, the extraction-wash apparatus is composed of a body 30 and a detachable cover 42 which is secured to the body by a conventional fastener (not shown). The body has a passage extending along a straight axis through which the filaments 13 travel for treatment. The passage includes a first extraction chamber 41 with outlets 43 connected to pipe 31 for draining the chamber and continues with a first passage length 44 joined to a second passage length 46 somewhat larger in cross section than passage length 44. A second extraction chamber 48 with outlets 47 connected to pipe 33 for draining the chamber is connected between second passage length 46 and a third passage length 49. A first pair of conduits 50 are angularly disposed into the passage at the junction of extraction chamber 41 and cylindrical length 44 to provide flow paths into chamber 41 for air supplied from pipe 32 counter-current to the filament travel. A second pair of conduits 52 are angularly disposed into the passage at the junction between the first length 44 and the second length 46 of the passage to provide flow paths into the length 46 for water supplied from pipe 35 co-current with the filament travel. Finally, a third pair of conduits 54 are angularly disposed into the passage at the junction of the second extraction chamber 48 and the length 49 to provide flow paths into chamber 48 for air supplied from pipe 34 counter-current to filament travel.
Referring now to FIGS. 3 and 4, orifices 52 intercept the passage at an angle A of about 15° while orifices 50 intercept the passage at an angle B of about 45°.
A useful embodiment employs rectangular slots 0.030 inch (0.764 mm.) wide and 0.281 inch (0.716 mm.) deep for conduits 50, 52 and 54, a 4-inch (10.0 cm.) long cylindrical section of 0.281 inch (0.716 mm.) I.D. for length 44 and a cylindrical section of 0.34 inch (0.890 mm.) I.D. for length 46.
In operation, high velocity streams of air from orifices 50 impinge against the moving filaments 13 and generate a highly turbulent action in extraction chamber 41 which removes solvent rapidly from the filaments to a receiver (not shown) via drains 43 and drain line 31. The filaments pass through a liquid free length of passage 44 carrying air along with them before engagement with water streams from orifices 52. The velocity of the dual water streams is adjusted to coincide closely with yarn speed. Below the orifices 52 the yarn passage is slightly enlarged, i.e., length 46 has a somewhat greater cross-sectional area than length 44 and provides a highly turbulent mixing action of air and water which reduces drag on the filament and assures maximum diffusion of the water into the filament bundle. At the end of length 46, the passage enlarges and blends into extraction chamber 48 where high velocity streams of air from orifices 54 impinge against the moving filament bundle in chamber 48 and generate a highly turbulent mixture of water solvent and air which is rapidly removed to a holding task (not shown) via drains 47 and pipe 33 leaving the filament bundle then to pass through liquid free passage length 49 and on to further processing or to a package windup. The function of the extraction chambers in combination with their respective jet orifices is critical to the operation of the system because by removing essentially all the liquid from the passage at these locations permits the filaments to pass through lengths 44, 49 with virtually no frictional drag and consequently no tension build up is encountered when passing through the successive stages. This tends to open the filament bundle and reduce resistance for removal of interstitial solvent. The filaments emerging from the extraction-wash apparatus are virtually free from excess liquid which obviates the need for cumbersome friction producing sealing devices.
The apparatus is not limited to a single set of impingement orifices but may also include a plurality of dual impingement orifices 52 arranged in series along the length 46. Each set of orifices would require an extraction chamber which would be interposed between successive sets of orifices along with a liquid free length of passage such as 49.
Although this invention has been disclosed in terms of using water as the washing liquid, it will be appreciated that other liquids can be used. For example, when the filaments contain sulfuric acid, a dilute (ca 1% aqueous solution of NaOH may be used to neutralize the acid and also remove Na 2 SO 4 formed. | A yarn extraction and washing apparatus in which a particular arrangement of the yarn passage through the apparatus and fluid conduits connected to the yarn passage for washing and stripping liquid from the yarn and its method of use permits the stripped yarn to travel at a very low tension level. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to GB 1203929.3, filed Mar. 6, 2012, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to conduits and devices provided within conduits to collect, or act as a barrier against, an unwanted solid or liquid matter travelling along the conduit. In particular, but not exclusively, the invention relates to devices which can be retro-fitted within an engine air inlet duct of a vehicle to prevent or inhibit ice reaching a downstream component such as a turbocharger.
BACKGROUND
[0003] In a vehicle engine, a small amount of unburned fuel and exhaust gases will escape around the piston rings during combustion and enter the crankcase. The fuel and gases are referred to as blow-by gas and the vehicle includes a crankcase ventilation system to deal with the blow-by gas. To reduce emissions to the atmosphere, the blow-by gas is typically recycled back into the combustion chamber of the engine. This is done by mixing the blow-by gas with intake air, upstream of the turbocharger if the engine includes this. The blow-by gas, and thus the mix of blow-by gas and intake air, contains oil from the crankcase. The intake air can contain moisture, snow and the like, depending on the environmental conditions.
[0004] An oil and water separator is often present upstream of the turbocharger to reduce the amount of water and oil present in the air flowing towards the combustion chamber. Nevertheless, even if a separator is used, the blow-by gas can contain water which can freeze to ice if the vehicle is in a cold environment. This ice can hinder air flow in the ducting or form pieces of ice chunks which can cause damage to components, such as the compressor vanes of the turbocharger. The forming of ice can occur while the engine is switched off or idling.
[0005] A sump may be provided in the air ducting and ice can form here when oil vapour enters the ducting and encounters the cold air stream. Since the water/ice has an oil content, and the ducting has an oil coating, the ice tends not to adhere to the inner surface of the ducting and is therefore drawn into the turbocharger, particularly during high acceleration.
[0006] It is desirable to provide improved means of inhibiting the formation of ice and/or inhibiting the formed ice from flowing downstream, such as to the turbocharger.
SUMMARY
[0007] In a first disclosed embodiment, a device is adapted for insertion into a fluid-carrying conduit to form a sump for separating out and trapping non-gaseous matter. The device comprises a barrier plate adapted to longitudinally divide a length of the conduit (thereby defining a passageway for gaseous matter above the barrier plate and a sump for collecting non-gaseous matter below the barrier plate), a spacer extending from a lower surface of the barrier plate and configured to contact a lower inner surface of the conduit below the barrier plate and space the barrier plate from the lower inner surface, and a frame member extending from an upper surface of the barrier plate and configured to contact an upper inner surface of the conduit above the barrier plate. The spacer and the frame member positively position the barrier plate within the conduit to form the sump.
[0008] In another disclosed embodiment, a device adapted for insertion into a conduit to form a sump comprises a barrier plate, a spacer extending from a lower surface of the barrier plate, and first and second frame members extending from an upper surface of the barrier plate at spaced-apart locations. The frame members are approximately annular and oriented obliquely to one another, and the spacer and the frame members are configured to contact interior surfaces of the conduit to positively position the barrier plate therein and urge the conduit to a bent condition, In the bent condition, a sump is formed between the lower surface of the barrier plate and the conduit adjacent to the spacer adjacent a lowest portion of the conduit.
[0009] In another disclosed embodiment, apparatus for separating non-gaseous matter from gaseous matter comprises a conduit having a flexible section, and a device within the flexible section forming a sump to collect the non-gaseous matter. The device comprises a barrier plate oriented generally horizontally to longitudinally divide a length of the conduit into a passageway (for the gaseous matter) above the barrier plate and a sump (for collecting the non-gaseous matter) below the barrier plate, a spacer extending from a lower surface of the barrier plate and contacting a lower inner surface of the conduit, and first and second frame members extending from an upper surface of the barrier plate at spaced-apart locations to contact an upper inner surface of the conduit above the barrier plate. The spacer and the frame member positively position the barrier plate within the conduit, and the frame members are oriented obliquely to one another to urge the flexible section of the conduit into a bent shape having a lowest portion defining the sump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0011] FIG. 1 is a schematic view of an engine system of a vehicle;
[0012] FIG. 2 is a perspective view of a separator device and two conduits;
[0013] FIG. 3 is a perspective view of the separator device of FIG. 2 inserted within one of the conduits;
[0014] FIG. 4 is another perspective view of the separator device of FIG. 2 ;
[0015] FIG. 5 is another perspective view of the separator device of FIG. 2 ; and
[0016] FIG. 6 is a semi-transparent perspective view of the separator device of FIG. 2 fitted within one of the conduits.
DETAILED DESCRIPTION
[0017] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0018] FIG. 1 shows an engine system 10 of a vehicle. Blow-by gas in the crankcase of the engine 12 is recycled back to the engine 12 by mixing the blow-by gas with intake air 14 upstream of a turbocharger 16 . The blow-by gas may first pass through an oil and water separator 18 before flowing into a first intake air duct 20 via a side port 22 . The first intake air duct 20 is connected to a second intake air duct 24 by a clamp connector 26 . A device 30 is provided within the second intake air duct 24 . The first intake air duct 20 is connected to the turbocharger 16 and a third duct 28 connects the turbocharger 16 to the engine 12 . One or more of the ducts 20 , 24 , 28 may be flexible.
[0019] FIG. 2 shows the device 30 prior to insertion within the second intake air duct 24 . The device 30 includes a stop member or lip 32 for limiting the longitudinal insertion of the device 30 . The lip 32 is of sufficiently large radius that it abuts an end of the second intake air duct 24 to prevent further insertion. This is shown in FIG. 3 . Then, the device 30 is restrained in its longitudinal position when the second intake air duct 24 is connected to the first intake air duct 20 using the clamp connector 26 . The lip 32 may also abut an end of the first intake air duct 20 and/or the clamp connector 26 to prevent longitudinal movement towards the first intake air duct 20 .
[0020] FIGS. 4 and 5 show the device 30 in more detail and FIG. 6 shows the device 30 within the connected ducts. The device 30 may be an injection moulded plastic such as polypropylene.
[0021] The device 30 comprises a barrier plate 34 which, in use, longitudinally divides a length of the second intake air duct 24 . This defines a main passageway 36 above barrier plate 34 for the mix of air and blow-by gas and a sump 38 below the barrier plate 34 for unwanted fluid or matter such as snow, ice or water.
[0022] As seen best in FIG. 4 , the device 30 includes spacers for positioning the barrier plate 34 above a lowest portion of the second intake air duct 24 to define the sump 38 . The spacers may comprise a first beam 40 extending in a longitudinal direction and a second beam 42 extending in a lateral direction. Both of the spacer beams 40 , 42 may include a recess 44 to allow unwanted fluid or matter to pass from side of the beams to the other. The laterally extending second beam 42 may have an arcuate base surface so as to correspond to the circular inner surface of the conduit. Also, as explained below, the second intake air duct 24 may include a bend at the location of the device 30 and the longitudinally extending first beam 40 may have an arcuate base surface so as to correspond to the arcuate inner surface of the bend.
[0023] The support features may also include a contact member in the form of a rigid frame for contacting other portions of the inner surface of the second intake air duct 24 . In the depicted embodiment, the frame comprises two approximately annular rings 46 , each of which contacts substantially the entire circumference of the inner surface of the conduit at a cross section of the first intake air duct 20 . The two rings 46 are spaced apart and may be connected by struts 48 . The frame therefore contacts the inner surface of the second intake air duct 24 at two spaced-apart cross sections of the second intake air duct 24 . By “approximately annular,” it is meant that one or more of the rings 46 may not be perfectly circular, and/or may not form a complete 360° of a circle. For example, the rings 46 may be described as approximately annular although they may not extend below barrier plate 34 , as beams 40 , 42 may be located there.
[0024] The two rings 46 may have rigid walls which are oriented obliquely, rather than parallel, to each other. When the device 30 is positioned within the flexible second intake air duct 24 , the obliquely oriented rings 46 impose a bend on the length of second intake air duct 24 . The imposed bend is generally U-shaped with the bight of the U downward and so the barrier plate 34 defines the sump 38 at the lowest portion of the U-shaped bend as shown in FIG. 6 .
[0025] The barrier plate 34 may have an approximately oval perimeter to correspond to the inner surface of the second intake air duct 24 when bent to the U-shape. However, a small clearance may be provided between the barrier plate 34 and the inner surface to allow liquid or solid matter to pass downward into the sump 38 .
[0026] Also, the barrier plate 34 may include an aperture 50 . The aperture 50 may be provided adjacent to a leading portion of the barrier plate 34 with respect to the direction of flow of the air 14 and blow-by gas. A louver 52 may be provided adjacent to the aperture 50 to direct unwanted fluid or matter towards the sump 38 .
[0027] The under-side of the barrier plate 34 may be formed to be rough to promote the adherence of ice. In contrast, the upper surface of the barrier plate 34 is preferably formed to be smooth to inhibit any build-up of ice on the upper surface. The term “rough” is to be interpreted as having a sufficiently high mechanical roughness suitable to promote adherence of the unwanted matter as will be known to the skilled person. The term “smooth” is to be interpreted as having a sufficiently low mechanical roughness suitable to inhibit adherence of the unwanted matter as will be known to the skilled person.
[0028] At least a portion of the barrier plate may comprise a mesh adapted to allow the passage of carried fluid to and from the sump but prevent unwanted matter from exiting the sump. The mesh may be provided at a trailing portion of the barrier plate with respect to the direction of flow of the carried fluid.
[0029] Alternatively or in addition, the barrier may include one or more barrier members adapted to allow the passage of carried fluid to and from the sump but prevent unwanted matter from exiting the sump. Each barrier member may comprise a protrusion or tooth. The barrier members may be provided at a trailing portion of the barrier plate with respect to the direction of flow of the carried fluid.
[0030] In use, the device 30 can readily be retro-fitted to an existing engine system 10 . The first and second intake air ducts are disconnected at the clamp connector 26 and the device 30 is inserted into the second intake air duct 24 until the lip 32 abuts the end of the second intake air duct 24 . The first and second intake air ducts are then reconnected which fixes the position of the device 30 .
[0031] During operation of the engine 12 , a mix of air and blow-by gas is drawn along the first and second intake air ducts. Any snow, ice or water present in the mix will tend to fall into the sump 38 where it will be retained. Specifically, ice particles will be small enough to pass through the aperture 50 of the barrier plate 34 but too large to pass through the clearance between the barrier plate 34 and the inner surface of the duct 24 .
[0032] As the engine warms, heat transferred to the second intake air duct 24 will melt any snow or ice in the sump 38 . As a fluid, the water can pass through the clearance thus emptying the sump 38 . This is assisted by intake air being directed into the sump 38 to act upon the contents of the sump 38 . The intake air is directed first by the bend geometry imposed by the device 30 and then by the position of the aperture 50 at the leading edge of the barrier plate 34 and the louver 52 provided at the aperture 50 . The sump 38 has therefore been purged and is available to collect future unwanted matter.
[0033] The device is inexpensive to produce and simple to install and can be retro-fitted without any modification to existing components. The device geometry can be adapted to suit any particular size of ducting (which are provided in standard sizes).
[0034] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. | A conduit carrying gaseous matter has a device inside it forming a low-lying sump for separating and collecting non-gaseous matter. The device fits within a flexible section of the conduit and includes a barrier plate oriented generally horizontally to longitudinally divide a length of the conduit into a gas-carrying passageway (above the barrier plate and a sump (below the barrier plate, a spacer extending from a lower surface of the barrier plate, and first and second frame members extending from an upper surface of the barrier plate at spaced-apart locations. The spacer and the frame member contact inner surfaces of the conduit to positively position the barrier plate within the conduit, and the frame members are oriented obliquely to one another to urge the flexible section of the conduit into a bent shape having a lowest portion defining the sump. | 5 |
BACKGROUND
Custom home entertainment systems can include matrix switches controlled by a central control system that allow a user to select among plural sources for video contents and among plural displays on which to view content. Such arrangements can allow different family members to view different contents in different rooms and allow a viewing in progress to follow a viewer who moves from one room to another. This arrangement also allows for all of the various video sources to be hidden in a remote location, leaving only the video display visible in the living areas.
However, the transition to high-definition video has introduced some challenges to matrix switching. The predominant audio and video interconnect system for high-definition video is HDMI, which includes an optional Consumer Electronics Control (CEC) protocol that allows any HDMI connected device to issue commands to any other HDMI connected device that supports the CEC protocol. The CEC protocol assumes a single video sink, e.g., display, and cannot readily be used with a home entertainment system having the two or more video sinks. Moreover, CEC implementations tend to be manufacturer-specific, which complicates control of home entertainment systems with devices from different manufacturers. While video devices can be controlled without using CEC, e.g., using a network of IR transmitters, such approaches tend to be cumbersome, expensive, and unreliable. What is needed is a more convenient and elegant approach to selecting HDMI sources and sinks.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic diagram of a home entertainment system in accordance with an embodiment of the invention.
FIG. 2 is a schematic diagram of a CEC command processor of the home entertainment system of FIG. 1 .
FIG. 3 illustrates a code database of the CEC command processor of FIG. 2 .
FIG. 4 is a flow chart of a process implemented in the home entertainment system of FIG. 1 .
DETAILED DESCRIPTION
In accordance with the present invention, a home-entertainment system 100 includes an HDMI switch 102 connected to a television (TV) 112 , a projector 114 , a satellite box 116 , and a DVD player 118 , as shown in FIG. 1 , respectively connected to HDMI ports P 1 -P 4 . HDMI switch 102 provides complementary virtual HDMI devices 122 , 124 , 126 , and 128 to interact respectively with devices 112 , 114 , 116 , and 118 so that the latter can be controlled using CEC commands, including manufacturer-specific CEC extensions; this allows CEC physical addresses to be assigned to virtual and actual HDMI devices according to the CEC specification. The HDMI switch prevents CEC commands from being transmitted from one HDMI port to another HDMI port, this allows more than one CEC sink to be used and avoids conflicts and collisions that might otherwise occur due to the different CEC extensions, e.g., implemented by different manufacturers. Since CEC commands are used for device control, workarounds such as infrared-based systems are not needed.
The HDMI™ (High-Definition Multimedia Interface) standard developed and licensed by the HDMI consortium, is a high-speed digital interface for communicating audio and video signals between sources (such as DVD players, satellite boxes, cable boxes, etc.) and sinks (typically video display devices such as televisions or projectors). Consumer Electronics Control (CEC) refers to an auxiliary communication protocol and interconnect which is part of the HDMI standard that enables control messaging between members of an HDMI connected system. Devices which support CEC enable a user to manage a plurality of sources connected via HDMI to run operations such as ‘one touch play’. Using CEC, the user may, for example, use one remote control to turn on a sink, source, and AV (audio-visual) at the same time, and to adjust the system volume of that receiver. The commands required for this are delivered by the remote control to a single member of the HDMI system, usually the sink, which then uses the CEC protocols to communicate to the other members of the system what functions they should perform.
The CEC interconnect uses a one-wire shared bus topology included in a standard HDMI connection cable. Being a single wire, multi-drop interconnect, CEC requires physical addresses for all members. Normally, upon hot-plugging, each CEC source device obtains a physical address by reading the Extended Device Identification Data (EDID) of the system's single sink device, to which it is attached. Logical addresses are then allocated based on product type using automatic mechanisms built into CEC protocols. CEC devices always have both physical and logical addresses.
The CEC specification includes support for customized commands. This enables different vendors to create proprietary CEC based networks between products of their own. Examples of such modified CEC base networks include: Anynet (Samsung), Aquos Link (Sharp), BraviaLink (Sony), RegzaLink (Toshiba), RIHD (Onkyo), Simplink (LG), VieraLink (Panasonic/JVC), Easylink (Philips) and NetCommand for HDMI (Mitsubishi).
It should be noted that the CEC interconnect and message topology is designed to only support a tree structure topology wherein it is assumed that a single sink is at the top of the tree and is the sole arbiter for the allocation of physical addresses to all devices directly connected to it. This presents a challenge in the design of multi-room home entertainment systems, e.g., in which AV sources provide content to plural displays in plural rooms. HDMI switch 102 addresses this problem.
HDMI switch 102 includes a user-command receiver 150 for receiving user commands, e.g., via remote controls 142 and 144 . Remote control 142 is programmed to control television 112 and to select the content to be displayed on television 112 . So that it can be used by a person viewing television 112 , remote control 142 is typically kept in the same room that television 112 is situated in. In the illustrated case, this is living room 146 . Remote control 144 is programmed to control projector 114 and to select the contents to be displayed by projector 114 . So that it can be used by a person viewing a screen on which projector 114 projects contents, remote control 144 is typically kept in the same room that projector 114 (or at least its screen) are situated in. In the illustrated case, this is family room 148 . More generally, the invention provides for HDMI switches with any number of source and sink ports, and remotes for each sink or each room having a sink. HDMI switches can have dedicated source and sink ports or ports that can be selective configured to serve as sink or source ports.
Remotes 142 and 144 typically communicate with HDMI switch 102 wirelessly using wall-penetrating RF signals (as opposed to infra-red signals); in an alternative embodiment, infra-red is used. To this end, HDMI switch 102 includes a user-command receiver 150 . Alternatively, remotes can communicate with a high-level control center which, in turn, communicates with an HDMI switch, e.g., via a wired interface. Receiver 150 demodulates user commands and provides them to a CEC command processor 152 of HDMI switch 102 .
CEC command processor 152 is responsible for creating complementary (to connected real HDMI devices) virtual HDMI devices 122 , 124 , 126 , and 128 . For example, CEC command processor 152 manages address assignment from sinks and to sources. In addition to sources and sinks, the CEC specification provides for “repeaters”, e.g., AV receivers. For example, AV receivers can be inserted at nodes R in FIG. 1 . In this arrangement, the connected sink provides a physical address to the repeater and the repeater assigns a physical address to the HDMI switch port to which it is connected. From the perspective of HDMI switch 102 , a repeater is a sink; accordingly, operation with repeaters is not detailed separately herein.
In addition to handling CEC addressing, CEC command processor 152 translates user commands into CEC commands for controlling connected HDMI devices. For example, a user may interact with remote 142 , in effect commanding that television 112 be turned on. Remote 142 translates this to “turn on the device connected to HDMI port P 1 . CEC command processor then translates this to a CEC “turn on” command, which it then routes to television 112 via port P 1 .
Other commands may require more complex actions. For example, a user may command “select DVD changer as source for television”. CEC command processor 152 can then command an HDMI data switch 154 of HDMI switch 102 to configure itself so that HDMI port P 4 is connected to HDMI port P 1 . HDMI data switch allows HDMI data but not CEC commands to pass between HDMI ports P 1 -P 4 . This eliminates problems associated with incompatible CEC command extensions and logical address conflicts and collisions. In some alternative embodiments, a CEC command processor translates commands from one HDMI device to conform to the extensions of another HDMI device, thus allowing some inter-device commands while still avoiding compatibility problems.
As shown in FIG. 2 , CEC command processor 152 includes a controller 202 , non-transitory controller-readable media 204 encoded with code 206 , CEC state machines 212 , 214 , 216 , and 218 for representing the respective states of virtual HDMI devices 122 , 124 , 126 , and 128 ( FIG. 1 ), and drivers 222 , 224 , 226 , and 228 for transmitting CEC commands out ports P 1 -P 4 ( FIG. 1 ). Code 206 , when executed by hardware controller 202 defines address assignment module 230 , command translation module 232 , device database 234 , and code database 236 . Address assignment module 230 handles address assignments during initialization. Command translation module 232 translates user commands into CEC commands that are issued to HDMI devices 112 , 114 , 116 , 118 .
Command translation module 232 access device database 234 when translating user commands into CEC commands. Device database 234 associates each port with a device type and code set (CEC commands plus manufacturer extensions). Device database 234 is typically populated automatically during address assignment.
Having determined the code set for the target HDMI device, command translation module 232 accesses code database 236 , which is shown in greater detail in FIG. 3 . Code database 236 is pre-populated with translations of user commands into code sets for different manufacturers, as shown. Code database 236 can be updated via a firmware update, e.g., via an installer interface. In an alternative embodiment, a code database includes user programmable sections for devices not represented in the preset code sets.
In FIG. 3 , code database includes translations for several manufacturers' extended CEC code sets. Command translation module 232 knows the relevant code set (A, B, C, or D, any of which can correspond to any of the manufacturers represented in FIG. 3 . Command translation module 232 can use the code set to select a table from code database 236 and then lookup the appropriate translation from that table. For example, a user can issue a command to turn on a Toshiba television (in which code set A is “Regzalink”). The desired command translation can be found in the “Toshiba Regzalink” table of code database 236 .
The translation may or may not be straightforward. For example, a user command may call for turning off television 112 and all sources connected to it. Command translation module 232 may determine that cable box 116 is in use as a source for projector 114 and elect not to turn off cable box 116 .
A process 400 implemented by HDMI switch 102 , command processor 152 , and code 206 is flow charted in FIG. 4 . At 401 , a sink assigns a physical address to the HDMI port to which it is connected. In the case a repeater is inserted between a sink and HDMI switch 102 , the sink assigns a physical address to the repeater and the repeater assigns a physical address to the HDMI port to which it is connected. At 402 , the connector port (or associated virtual HDMI device) communicates its identity to the sink or repeater that assigned its physical address. This identity is as a source from the same manufacturer as the sink or repeater. At 403 , the virtual sinks assign physical addresses to HDMI sources.
In use, at 411 , a user can select a device and command using a remote control, which transmits a user command to HDMI switch 102 . At 412 , HDMI switch 102 receives the user command. More specifically, receiver 150 receives the user command and converts it for CEC command processor 152 . At 413 , CEC processor 152 identifies that port and action called for by the user command.
At 414 , a command conversion can be implemented. In some cases, a direct translation is performed without any conversion. For example, a simple “turn on device connected to port P 2 ” could be implemented directly. However, in some cases, a command to turn off the device connected to port P 2 may be changed to a “Power Toggle” command as the device may not have discrete power on and power off commands.
At 415 , CEC processor 152 identifies the manufacturer and model number (and, thus, the device type) of the attached device and code set for the user command. At 416 , CEC processor 152 translates the command. At 417 , CEC processor issues the translated command. At 418 , the device state of the target HDMI device is changed as commanded.
In some embodiments, a device may respond with a command of its own issued to the complementary virtual device. In process 400 , this reply is discarded. However, in an alternative embodiment, commands from HDMI devices can be allowed to pass through converted or unconverted to another HDMI device or be transferred back to the user command receiver 150 to be used elsewhere (i.e. in a higher level of the control system). These and other variations upon and modifications to the illustrated embodiments are within the scope of the claims. | An HDMI™ (High-Definition Multimedia Interface) switch includes a CEC (Consumer Electronics Control) processor for controlling high-definition audio-visual (AV) equipment. The CEC processor accepts user commands and translates them to control HDMI devices over HDMI; the translations can be manufacturer specific so that devices with different CEC implementations can be combined in a single system. CEC communications between HDMI devices is precluded or at least controlled to avoid problems due to incompatible CEC implementations and unwanted interactions. The CEC processor causes the HDMI switch to appear as an HDMI source to HDMI sink devices and as an HDMI sink to HDMI source devices for the purposes of assigning physical addresses. While CEC is designed to handle AV systems having only one sink (display), the novel HDMI switch provides for CEC-controlled AV systems with multiple displays, e.g., in different rooms. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a print operation processing device for a serial printer such as an ink-jet printer and the like to execute a cycle of operation for supplying, printing and ejecting a discrete paper or to repeat the above-mentioned operation for continuous printing on discrete papers where the succeeding paper is overlapped at a desired position of the current paper in accordance with a printing area of the current paper so as to execute a successive printing effectively for raising a throughput of the printing by saving ejecting time for blank area of the current paper.
[0003] 2. Brief Description of the Related Art
[0004] The print operation processing device mentioned above has a function to execute a successive printing on a plurality of discrete papers. Usually the print operation for the discrete paper consists of paper supply, printing and paper ejecting procedures etc. When a successive printing on a plurality of discrete papers are required, the requirements are fulfilled by the conventional systems when the above-mentioned cycle of print operation on the discrete paper is repeated.
[0005] The above-mentioned print operation processing device attains the print operation on the discrete paper or a plurality of the discrete papers by a combination of paper supply, printing and paper ejection procedures on one discrete paper, but these procedures are executed on the discrete paper basis independently even when the successive printing is required. Some printers execute paper ejection and supply procedures simultaneously.
[0006] In the above-mentioned conventional ordinary print operation processing devices, the print operation for each paper is completely independent. Though some printers attain ejecting the current paper and supplying the succeeding paper simultaneously, operations are executed routinely regardless of the area size to be printed and without overlapping papers. Consequently total throughputs of the print operations are insufficient.
[0007] When a large amount of data with different contents for each paper are printed by employing the above-mentioned means, for example, the throughput of the printing is improved to a certain extent compared with printing by the ordinary system. Since succeeding paper is supplied partly parallel to ejecting the current paper only after current paper is ejected out of the printing margin in the sub scanning direction, the throughput of the printing is improved to some extent compared with the ordinary printing procedure where paper supply and ejection are executed independently. However the effect is limited due to that paper ejection and supply procedures are automatically executed regardless of data amount to be printed on the current paper.
[0008] Usually when data with different contents for each paper are printed continuously on discrete papers, a series of print operations are executed according to the following sequence as shown in FIG. 2 which is explained later. The printing sequence comprises (1) paper supply, (2) repeat operations of printing in the main scanning direction and paper feed in the sub scanning direction, (3) paper ejection when no data to be printed remain for the current paper or when the current paper passes the lower margin.
[0009] As mentioned above a plurality of the same printings on discrete papers are executed in the same way as described above. In these printings, a time for printing is determined by a time for printing in the main scanning direction, a time for paper feeding in the sub direction and a time for paper ejection/supply. Which affects and determines the maximum throughput of the print operation processing device.
SUMMARY OF THE INVENTION
[0010] The present invention is carried out in view of the above-mentioned problems. The objective of the present invention is to provide a print operation processing device capable of improving the total printing throughput by a function of the device to supply the succeeding paper even when the current paper is in a supplied state, once a termination of the printing on the current paper is confirmed by parameters from a host computer or by monitoring paper feeding amount of the current paper in the printer so as to feed paper effectively in a partially overlapped state with the succeeding paper without changing the printing velocity in the main scanning direction and the paper feeding velocity in the sub scanning direction.
[0011] A serial printer having one of the following arrangements (1) to (8) attains the objective of the present invention.
[0012] (1) A print processing device equipped in a serial printer comprising; an analyzing unit to analyze a printing command from an apparatus which transmits printing data, a storing area to store an analyzed result by the analyzing unit, a controlling unit to identify stored contents in the storing area and to control a paper feeding device, wherein; the controlling unit functions to supply a succeeding paper so as to overlap to a current paper after detecting a lower margin of the current paper according to the analyzed result stored in the storing area.
[0013] (2) The print processing device equipped in the serial printer according to (1) wherein; the controlling unit detects a blank area in the current paper as the lower margin of the current paper.
[0014] (3) The print processing device equipped in the serial printer according to (2) wherein; the controlling unit detects a blank area according to information on a printing area before a host computer transmits the printing data.
[0015] (4) The print processing device equipped in the serial printer according to (3) wherein; the detecting function to detect the blank area is activated or deactivated by the host computer or by the printer, and the controlling unit has a setting means to overlap the succeeding paper to the lower margin of the current paper when the detecting function is deactivated in a discrete paper printing.
[0016] (5) The print processing device equipped in the serial printer according to (4) wherein; the setting means is capable of setting a condition where papers are supplied without overlapped state.
[0017] (6) The print processing device equipped in the serial printer according to (1) wherein; the controlling unit supplies the succeeding paper at any timing before ejecting the current paper, and when the paper supply is at an incapable timing due to structural factors of said paper supplying device the succeeding paper is reserved until the timing returns to the capable timing of the paper supply.
[0018] (7) The print processing device equipped in the serial printer according to (1) wherein; the storing area to store the analyzed result has a storing portion to store a supplying state of the paper, and the controlling unit has a controlling function to write and to read parameters in the storing portion to store the supplying state during supplying or ejecting operation of the paper.
[0019] (8) A print processing method for a serial printer comprising operations of; analyzing a printing command from a device which transmits printing data by an analyzing function arranged in the printer, storing an analyzed result by said analyzing function in a storing area arranged in the printer, identifying contents in the storing area and controlling a paper feeding device by a controlling unit arranged in the printer, wherein; the controlling unit functions to supply a succeeding paper so as to overlap to a current paper after detecting a lower margin of the current paper according to the analyzed result stored in the storing area.
BRIEF DESCRIPTION OF DRAWINGS
[0020] [0020]FIG. 1 is a sequence flow chart of a serial printer of an embodiment of the present invention showing from a step of “Analyze Command” to a step of “Supply Paper”.
[0021] [0021]FIG. 2 is a fundamental operating sequence flow chart (from paper supply to paper ejection) of the serial printer of the present invention.
[0022] FIG. 3 is a block diagram depicting a main arrangement of the serial printer of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Hereinafter one of the embodiments of the present invention is described in detail by referring drawings.
[0024] The main arrangement of serial printer of the present embodiment is shown in FIG.3. This arrangement is not limited in its specifications, it is applicable to all serial printers having functions described above.
[0025] A numeric character 1 is a serial printer, a numeric character 2 is a data receiving unit, a numeric character 3 is a data analyzing unit, a numeric character 4 is a print operating unit, a numeric character 5 is a paper feed operating unit and a numeric character 6 is a host computer for transmitting data to be printed to the printer 1 .
[0026] FIG. 2 is the flow chart depicting a fundamental operating sequence of the printer 1 operated by commands from the host computer. A timing for a first paper supply is depend on a characteristic of the printer and specifications for analyzing printing commands, but it is not a significant point in the present invention so that the further explanation on the timing is omitted.
[0027] After supplying a paper to the printer at a step S 11 , a printing command from the host computer is analyzed at a step S 12 . Then the printing on the paper is executed by repeating a cycle comprising a step S 13 (a print operation in the main scanning direction) and a step S 14 (a feeding operation in the sub scanning direction). The print operation on one sheet of the paper is finished by a command indicating no remaining data for printing or by a command instructing paper ejection transmitted from the main computer to the printer. When the printer recognizes ejecting conditions, that is, the printer recognizes the end of a printing area of the current paper, a step S 15 of ejecting the current paper is initiated. In case data to be printed on the succeeding paper still remain, a print operation on the succeeding paper is executed without an idle time waiting for the next step, followed by supplying the succeeding paper in the step S 11 and ejecting the current paper in the step S 15 simultaneously. The step of recognizing the end of printing area also includes detecting a blank area (an area where no data for printing are assigned) in the current paper. For that purpose, a method where the host computer transmits information on the printing area before transmitting data to be printed or a method where the printer detects the printing area by analyzing data to be printed is employable.
[0028] The above-mentioned procedure is described more specifically by referring the sequence flow chart in FIG. 1 illustrating from a step of analyzing command to a step of supplying the succeeding paper in the serial printer.
[0029] Here a step of receiving a command to eject the paper as one of the confirming means to initiate ejecting the paper is explained.
[0030] At step S 1 the data receiving unit 2 (FIG.3) reads data from the host computer 6 (FIG.3). At step S 2 the data are analyzed by the data analyzing unit 3 (FIG.3) and the data are stored in a storage area for the analyzed results (not shown). When the data include other commands except the command to eject the paper, the printing procedure returns to step S 1 . When the printer receives the command to eject the paper, the printer controls paper feed in accordance with the stored data. At step S 3 , “Analyzing Parameter”, the data analyzing unit (FIG.3) judges whether the parameter in the command to eject the paper indicates data for printing remain or not. When the parameter indicates no data for printing remain, the print operation is finished after ejecting the paper (step S 6 ).
[0031] At step S 3 when the parameter indicates the data for printing still remain, the print operation goes to step S 4 where paper ejecting conditions in an inputting device (not shown) arranged in the printer for changing paper feeding conditions and in a storage area (not shown) inputted via the inputting device are confirmed. If the paper supply is allowed, the print operation goes to step S 5 where overlapping supply of papers is executed. If not, the print operation goes to step S 7 where the paper is ejected and goes to step S 8 for discrete supply of the paper.
[0032] Hereinafter the above-mentioned print operation is explained again in other words for a better understanding. When the command to eject the paper is received, the printer 1 usually ejects the current paper after the print operation is finished. At step S 2 the printer 1 recognizes whether the succeeding printing is required or not by a parameter in the command set in the above-mentioned storage area via the above-mentioned inputting device indicating the data still remain. And the printer confirms the supply of the succeeding paper by referring the data stored in the above-mentioned storage area immediately before ejecting the current paper.
[0033] In the procedure to confirm the supply of the succeeding paper, the current medium is confirmed and judged whether the overlapping supply is allowed or not (step S 4 ). More specifically, specifications and functions of the current printer, and properties of the current medium are checked whether the overlapping supply is allowed or not. If not, the ordinary paper ejection (step S 7 ) is executed without executing the overlapping supply. Even when conditions allow the overlapping supply, but when an overlapping position is determined by the structure of the printer, the supply of the succeeding paper is reserved until the current paper reaches a position where the overlapping supply is possible. In other words, even when it is judged that the paper supply is allowed, but actually it is not allowed due to the structure of the printer, the papers are accumulated until the printer returns to a state where the paper supply is allowable.
[0034] When the situation is allowed and the overlapping supply is executed (step S 5 ), a distance between the printing area of the current paper and an ejecting surface (of the ink-jet printer, for example) is adjusted in accordance with a type and a size of the paper, if necessary.
[0035] A case when more than two sheets of the paper are overlapped owing to areas to be printed of respective papers, is also allowed, if conditions such as an accuracy of a paper supplying structure etc. are fulfilled. If the number of the paper to be overlapped is limited due to the accuracy, the supply of the succeeding paper is reserved according to the above-mentioned function until conditions are fulfilled.
[0036] In the previous example, the overlapping supply is executed according to the checked result of the parameter in the paper ejecting command. But if a command to specify the total number of paper for the current printing is generated or exists, it is used as a condition for supplying the succeeding paper. In this case procedures succeeding to the supplying the paper are the same as the preceding example.
[0037] Usually print operation processing device represented by the serial printer has its proper printing margins in the main and sub scanning directions. In this case only areas where the printing is not allowed (the lower end margin) may be overlapped by the above-mentioned means without detecting the above-mentioned lower margin or a blank area in the paper. In this case a function to activate/deactivate detecting the lower margin and the blank area should be preferably arranged in the host computer or the printer.
[0038] A feature of this method is that it can immediately respond to the conventionally used command for the printing without adding a new command and a parameter to the data of the host computer, namely, no restrictions on the transmitting side. However, it is less effective in terms of the paper feeding since the timing for the overlapping supply is not set by data to be printed or by controlling commands as the preceding example is.
[0039] Since these setting means can be set by the host computer or the above-mentioned inputting device of the printer, it is not necessary to specify a type of the host computer. Though conveying efficiencies of the paper are different depend on specifications of printers, more efficient paper conveyance may be attained by the present invention than by the conventional systems.
[0040] According to the preset invention, as already mentioned, the paper supply is realized at a proper timing determined by factors such as the size, type of the recording medium and supplying mechanisms etc., if the printing parameter information on the succeeding paper is added at the ejecting time of the current paper. By employing this method, since papers can be transferred by keeping a state where the blank area of preceding paper is overlapped to that of the succeeding paper so as to print different data on each paper successively, total throughput of the print operation is improved.
[0041] In addition it is possible to supply overlapped papers by overlapping the lower margin of the current paper to the upper margin of the succeeding paper. This method attains the improved throughput, even without means for transmitting the printing information on the succeeding paper from the host computer compared with ordinary printings (no overlapped supply). | The objective of the present invention is to solve a problem that a printing throughput is not improved so much in a conventional printing processing device arranged for example in a serial printer such as an ink-jet printer etc., due to a requirement to repeat printing in the main scanning direction and feeding a paper in the sub scanning direction, until a blank area where the printing is not allowed is confirmed in printing different data on respective discrete papers. To fulfill the objective a function to supply the succeeding paper while the current paper is held in the printer and means to change supplying conditions of the paper and to adjust overlapping extent of papers are arranged in a device where a print operation is executed by a combination of the printing in the main scanning direction and paper feeding in the sub scanning direction. | 1 |
FIELD
[0001] The embodiments of the present disclosure relate to the preparing of semiconductor wafers having active device die so as to increase the yield of those device die when packaged, in particular device die packaged in radio frequency identification devices (RFID) tags. In particular, the disclosure relates to an etching process to reduce the incidence of sidewall cracking on device die.
BACKGROUND
[0002] Integrated circuits (ICs) are typically produced by forming a plurality of ICs on a semiconductor substrate, such as silicon. The ICs include one or more layers formed on the substrate (e.g., semiconductor layers, insulation layers, and metallization layers). The individual ICs are separated by lanes. The finished ICs on the wafer are then separated into individual ICs by, for instance, sawing the wafer along the lanes. Separation of the wafer into individual ICs may be referred to as dicing. Sawing may be performed using various mechanical cutting and laser cutting methods. Mechanical cutting tools tend to cause chipping of the back-side or front-side of a substrate. Laser cutting tends to cut unevenly in metallization layers covering entirely or partly the saw lanes of the substrate.
[0003] During a stealth laser dicing process, the laser focuses into the material and melts the mono-crystalline silicon. The material re-crystallizes as polycrystalline silicon, which induces stress into the material due to higher volume of the poly-crystalline structure. This stress creates a crack, which is used for die separation.
[0004] For one particular type of product, a radio frequency identification device (RFID) tags, the feature for the die separation has become a challenge during the later stages of the RFID tag production process. Once the device die is embedded in a glue within the RFID tag, bending forces may be transferred from the die side into the laser modification zone (on the sidewalls of the embedded die) resulting in cracking at die edges.
[0005] There exists a need for eliminating this shortcoming in the assembly of RFID devices.
SUMMARY
[0006] The present disclosure has been found useful in the packaging of semiconductor devices which find their way into RFID tags and the like. RFID tags and other smart card devices undergo mechanical stress during their lifetime. For example, putting an RFID-enabled card in one's pocket can exert stress on the packaging structures. Over time, the accumulated stress of bending and crushing wears out the package and one or more electrical/mechanical connections to the RFID are broken; the RFID equipped device no longer works.
[0007] During the assembly process, side-wall stresses accumulate in the assembled device die. These stresses result from the wafer sawing/separation. In an example embodiment, a laser is used to cut through saw lanes of the active devices on the wafer substrate. The laser provides for narrower saw lanes between devices. For example a saw lane of about 15 μm is possible versus 80 μm for saw lanes cut with mechanical blade. However, the laser introduces modification zones of poly-crystalline silicon in cut areas where previously they were part of the single-crystal structure of the semiconductor device. These modifications zones are vulnerable to stress; the stress may cause cracks to begin in these modification zones and propagate into active areas of the semiconductor device. A dry-etching process removes these modification zones so that side-walls are substantially free of poly-silicon which in turn reduces the side-wall stress and lessens the probability of cracking.
[0008] In an example embodiment, there is a method for preparing integrated circuit (IC) device die from a wafer substrate having a front-side with active devices, the active devices having boundaries defined by saw lanes and a back-side. The method comprises mounting the front-side of the wafer onto protective foil. A laser is applied to the saw lane areas on the backside of the wafer, at first focus depth to define a modification zone, the modification zone defined at a pre-determined depth within active device boundaries. The protective foil is stretched to separate IC device die from one another and expose active device side-walls. The active device side-walls are dry-etched so that the modification zone is substantially removed.
[0009] In another example embodiment, an integrated circuit (IC) device die comprises an active device on a front-side surface and an under-side surface opposite the front-side surface; the active device is bounded by saw lanes. A plurality of vertical side walls are in the vicinity of the saw lanes, wherein the plurality of vertical side walls have modification zones of poly-crystalline silicon defined therein. The modification zones have been exposed to a plasma etch such that substantially all of the poly-crystalline silicon has been removed.
[0010] In an example embodiment, there is a method for preparing a laser cut device die with reduced side-wall stress, from a wafer substrate. The method comprises using a laser to cut the wafer substrate along saw lanes, the saw lanes defining device boundaries, so as to yield individual device die, An etch is used laser-induced stress to the side-walls of the individual device die
[0011] The above summaries of the present disclosure are not intended to represent each disclosed embodiment, or every aspect, of the present invention. Other aspects and example embodiments are provided in the figures and the detailed description that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
[0013] FIG. 1 illustrates the sources of stress in an IC device assembled in an RFID package;
[0014] FIGS. 2A-2B illustrate the device die edge cracking as a result of the stresses shown in FIG. 1 ;
[0015] FIG. 3 is a flow diagram of an process for preparing wafers according to an example embodiment;
[0016] FIGS. 4A-4B depict an example laser dicing process;
[0017] FIGS. 5A-5B is an example of locating the active device with infra-red imaging through the wafer substrate backside;
[0018] FIGS. 6A-6D illustrate an example embodiment of etching the silicon modification layer; and
[0019] FIGS. 7A-7B show an example of a silicon modification layer and its etching; and
[0020] FIG. 8 depicts a box plot of fracture stress v. degree of removal for two example process gases.
[0021] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0022] The disclosed embodiments have been found useful in preventing damage to active device die prepared for packaging in RFID tags, and the like. In an example, process, a “stealth dicing” process may be used for separating such a wafer into individual ICs. Stealth laser dicing allows for reduction of saw lane width spacing, from the normal width of about 60 μm about to 80 μm to a minimum width of about 15 μm. With this reduced saw lane width, the amount of potential good dies per wafer (PGDW) can be significantly increased. During this stealth laser dicing process, a modification zone is implemented into the silicon layer of the already thinned wafer. This modification zone leads to a crack that later can be used to separate the dies from each other with an expansion process.
[0023] Channels are formed in the one or more metallization layers on a front-side of the wafer along respective lanes along which the ICs are to be separated. These (separation) lanes are located between ICs and extend between a front-side of the wafer at the metallization layer(s), and a backside of the wafer at the silicon substrate. After forming the channels, the backside of the silicon substrate is thinned, and laser pulses are applied via the backside of the silicon substrate to change the crystalline structure of the silicon substrate along the lanes. This change in the silicon structure weakens the silicon in the lanes. The changed portions (i.e., “modification zone”) in the silicon substrate and the channels facilitate the propagation of cracks in the silicon substrate along the lanes during expansion of the wafer, while mitigating propagation of cracks outside of the lanes. With this approach, wafer separation can be achieved while mitigating issues that can arise from the formation of cracks.
[0024] However, with the “stealth dicing” process, there is a possibility of excessive die stress after the device die is packaged into an RFID tag. The die may crack along areas modified by the laser, resulting in reliability issues with the RFID tag to outright failure. Refer to FIG. 1 . An assembled device die 25 in an RFID tag 35 is subjected to stress exerted by blades 15 and roller 17 , not unlike forces a user's tag would encounter by being placed in a back pocket of his trousers. Area 10 shows an enlarged area to at which a stress 5 is significant. Refer to FIGS. 2A-2B . An example device die 50 (in a side-view) shows the cracking 20 along the edges. The same example device die 50 (in a top-view) shows cracking 30 along some edges.
[0025] More details of “stealth dicing” may be found in U.S. patent application (Ser. No. 13/687,110) of Sascha Moeller and Martin Lapke titled, “Wafer Separation” filed on Nov. 28, 2012 and is incorporated by reference in its entirety.
[0026] Further information on “stealth dicing” and “laser ablation” may be found in the product brochure titled, “Laser Application” of DISCO Corporation, Tokyo, Japan.
[0027] Additionally, a process for increasing device die yield for RFID tags may be found in U.S. patent application (Ser. No. 14/204,858 filed on Mar. 11, 2014) of Guido Albermann et al, titled, “Combination Grinding after Laser (GAL) and Laser On-Off Function to Increase Die Strength,” and is incorporated by reference in its entirety.
[0028] However, in the instant disclosure, it has been observed that there is an increased incidence of device die cracking directly attributable to the size of the modification layer. The removal of the modification zone with a dry etching process with a suitable etchant, such as xenon di-fluoride (XeF 2 ) gas, enhances not only the side-wall strength of the device die but also the whole device die structure, thereby mitigating device die cracking during assembly and allowing for a 15 μm saw lane for use with stealth dicing. Other gas etchants may include, in addition to XeF 2 , bromine tri-fluoride (BrF 3 ), chlorine tri-fluoride (ClF 3 ), and fluorine (F 2 ).
[0029] In an example process, the modification zone may be removed with the following recipe. The etching equipment used is a Xactix® XeF 2 Release Etch System manufactured by SPTS, San Jose, Calif.
[0000]
TABLE 1
Example XeF 2 Etching Recipe
Description
Range
Comments
XeF 2 flow rate
0.5 sccm-500 sccm
One example process uses
flow rates of about
5 sccm-50 sccm.
Cycle Time
1 s-9000 s
One example process uses
cycle times of 120 s to about
180 s.
Base Pressure
1-100 mTorr
One example process uses a
base pressure of about
21 mTorr.
Chamber
Shower Head Design;
Xactix ® XeF 2
exhaust below wafer-
Release Etch System used
chuck center.
in example process
[0030] In an example embodiment, the etching of the modification zone is done with a XeF 2 flow rate in the range of about 5 sccm to about 50 sccm (standard cubic centimeters per minute), a cycle time of about 120 seconds to about 180 seconds. The pressure used in this example embodiment is about 21 mTorr.
[0031] Refer to FIG. 3 . In an example process at step 110 , a wafer substrate having active device die on the front-side, undergoes a pre-back-grinding. For example, a pre-grinding thickness, of an eight-inch wafer (200 mm) is about 725 μm, for a six-inch wafer (150 mm) is about 675 μm. Note that this technique may be applied to wafer substrates of any size and may be useful for twelve-inch (300 mm) substrates. In an example process, a wafer is ground to a thickness of about 200 μm. It is desirable to achieve a minimum wafer thickness; however, it is limited by the technical ability to thin down wafers with 200 μm bumps. Thickness, in an example process, may be in the range of about 150 μm to about 250 μm. Next in step 120 , the front-side of back-ground wafer substrate is mounted onto a protective foil. Then in step 130 , the now-protected wafer substrate is oriented so that the back-side surface is exposed to the dicing laser. In step 140 , the laser is applied to the back-side of the wafer at a first focus depth to define a modification zone. Through infra-red or other imaging techniques, the position of the cutting lanes (i.e., saw lanes) is determined prior to cutting. In step 150 , the carrier foil is stretched to create an equidistant gap among side-walls of the laser-singulated device. In step 160 , the device side-walls are dry etched, with a suitable etchant, to remove the modification zone. In an example embodiment, xenon di-fluoride (XeF 2 ) is used. At step 170 , the wafer is re-oriented front-side up so that the support tape may be removed. In step 180 , the wafer is expanded to separate out the ICs that will be embedded into the RFID tag 180 . During the etching, there should be no substantive difference in etch selectivity between mono- or poly-crystal-Si. Further, to etch to a pre-determined depth there was no substantive difference in time between mono-crystalline silicon and poly-crystalline silicon. There should also be no difference in the etch rate depending on crystal orientation (e.g., {100}, {110}, and {111}).
[0032] In another example embodiment, the sidewalls may be etched with a suitable wet etchant to remove the modification zone. However, the active device areas would need to be protected from undesired etching from the wet etch.
[0033] Refer to FIGS. 4A-4B . In an example embodiment, an apparatus 200 with a lasers 220 focused at a prescribed depth (with a lens 230 ) performs a stealth laser dicing of a wafer substrate 210 on a saw lane 215 . The modification zone 235 b of the laser scan 235 a having a length of about 300 μm with a depth of about 50 μm is shown; the modification zone 240 b (at a point) of the laser scan 240 a is at a depth of about 50 μm and having a length of less than about 5 μm.
[0034] Refer to FIGS. 5A-5B . In an example embodiment, a wafer substrate 300 having device die 310 is scanned via infra-red shown in the alignment sight 305 . The saw lanes 320 are visible. The infra-red imaging permits the laser to perform the dicing of the saw lanes 320 which result in modification zones 330 .
[0035] Refer to FIGS. 6A-6D . Wafer substrate 400 having device die 410 has been laser diced on the saw lanes 420 . The carrier foil 430 is stretched so that equidistant spacing between the device die 410 is attained. The stretched-apart wafer 400 is placed into an etching apparatus. In one example embodiment, xenon di-fluoride (XeF 2 ) 55 is introduced. The laser-induced modification zone 415 (between mono-crystalline layers 425 ) is etched so that the poly-crystalline silicon is substantially etched away leaving minimal poly-silicon 435 .
[0036] Refer to FIGS. 7A-7B . In an example embodiment, having etched the device die, the user may observe on a device die 500 a modification zone of poly-silicon 520 sandwiched between mono-crystalline layers 510 . The active device 530 is on the surface. Panels P 1 -P 4 of FIG. 7B show example of the plasma etching of the modification layer 510 with P 1 have the least amount of etching and P 4 having the greatest amount. P 2 has more etching than the reference P 1 , but less etching than P 3 ; P 3 has less etching than P 4 .
[0037] In applying the etching to the modification zone, the dimension of the modification zone is not directly measurable; however, the appropriate amount of etching is determined by the shift of the distribution of the fracture strength values. The amount of material to be etched away may be determined, by running a design of experiments (DoE) and determining the point, at which the target improvement of die strength is achieved. One may see, that the target can be reached already for cases, where the modification zone is optically only slightly different from before (topography is not changed by etching, only stress is removed).
[0038] Refer to Table 1. Based on a study with a limited number of samples processed, one can conclude, that there is a significant difference between the side-wall treated groups and the reference. However, the statistical data also shows significant influence of other parameters, which are currently not analyzed or modelled yet (poor R 2 values).
[0039] In one embodiment, these factors are caused by the non-optimized design of the device for the process used and by the narrow opening of the kerf (inhomogeneous penetration of etchant into the kerf). The under-etching of the seal ring area and the part of the front-end structures is introducing new types of weak spots and new fracture mechanisms. To utilize the full potential of the process, the design of the device (scribe-lane width, passivation structure) would need to be adapted, to prevent forming of large overhang while allowing sufficient removal amount at the same time.
[0000]
TABLE 1
One-way ANOVA: Fracture Stress (MPa) versus Process/
Removal Combination
Source
DF
SS
MS
F
P
Pre/Removal
4
21368240
5342060
12.38
0
Error
415
1.79E+08
431418
Total
419
2E+08
S = 656.8 R-Sq = 10.66% R-Sq(adj) = 9.80%
Level
N
Mean
StDev
Reference_none
60
640.7
252.6
SF6_less
90
965.8
458.2
SF6_more
90
1373.1
919.1
Xe2F_less
90
1176.2
709.5
Xe2F_more
90
1104.1
641.4
Pooled StDev = 656.8
[0040] FIG. 8 illustrates the die strength improvement by using two different processes and etchants. The first gas is SF 6 and the second gas is XeF 2 . The process with SF 6 shows two box plots, one process 820 having less gas (i.e., the gas being dispensed at a lower pressure and/or flow rate) and one 810 having more gas (i.e., the gas being dispensed at a higher pressure and/or flow rate). Likewise, the process with XeF 2 shows two box plots one with less gas ( 830 ) and more gas ( 840 ).
[0041] The samples used are from a representative RFID tag product, with scribe lanes which are free of process control structures and other metal features. As can be seen from the ANOVA table, the variation of the fracture strength increases compared to the reference, while the average improves. One can attribute the increased variation to inhomogeneity of the kerf width and the different amount of under-etching due to variations in the stealth dicing kerf-position (i.e., meandering).
[0042] The RFID/Tag environment itself cannot be definitely specified as it is varying from product to product and per production process step. The die strength is determined by multiple factors of previous process steps, such as grinding or dicing. However, for example, a typical fracture strength is 600 MPa. Improvements of about 20%, that is greater than 700 MPa will already improve the performance in further production steps.
[0043] The ratio of improvement of die strength by removal of the modification zone was found to be about 200 MPa for a removal of about 0.1 μm (in the range of 0-1 μm). However when etching more than 1 μm in total a decrease of the die strength was observed, supposed to be related to etching below the front-end structures.
[0044] The design of the device to be subject to the proposed process needs to be optimized to achieve the best results. Generally, it can be said that a higher removal amount will increase the fracture strength, if negative side effects can be eliminated. To achieve this, the distance between the seal rings of the dies needs to be large enough, to make sure that the removal of material does not advance below the seal ring. Also, the area intended for etching should be free of passivation material, etc. In an example process, one could introduce a vertical etch stop into the device design (e.g. a modified seal ring structure). The exact design depends on the selectivity of the used gas, the thickness of the device, the distance between the devices, the process speed and the dicing tape used.
[0045] In an example test, the etching has completely removed the modification zone, so one may optically see in the SEM analysis that it is gone (See FIG. 7B ). The overlap on the extreme picture P 4 with very long etching is about 8 μm. The modification zone would be smaller than that (based on TEM analysis in literature).
[0046] In an example process, the pulse frequency is determined by the laser engine in use. The distance of the modification spots is determined by the dicing speed (usually 300 mm/s) and the pulse frequency. For one embodiment, the SDE03, it is about 3 μm. The spot size is depends on the laser power used, which may range from about 0.8 watts to about 1.4 watts (depending on thickness and substrate type).
[0000]
TABLE 2
Example Processes for Stealth Laser Dicing.
SDE01/DISCO
ML200/ACCT
ML300/ACCT
ML200+/ACCT
ML300+/ACCT
SDE03/DISCO
Average Power
W
0.8
0.8
0.8
1
1
1.4
Pulse width FWHM
ns
150
150
150
350
350
90
Repetition rate
kHz
80
80
80
90
90
90
Wavelength
nm
1064
1064
1064
1085
1085
1342
Peak Power
W
62.63
62.63
62.63
29.82
29.82
162.37
Duty Cycle
:1
0.0120
0.0120
0.0120
0.0315
0.0315
0.0081
p-t-p time
ms
0.01250
0.01250
0.01250
0.1111
0.01111
0.01111
Pulse Energy
μl
10.00000
10.00000
10.00000
11.11111
11.11111
15.55556
Photons per Pulse
5.36E+13
5.36E+13
5.36E+13
6.07E+13
6.07E+13
1.05E+14
Photon Energy
eV
1.17
1.17
1.17
1.14
1.14
0.92
[0047] Various exemplary embodiments are described in reference to specific illustrative examples. The illustrative examples are selected to assist a person of ordinary skill in the art to form a clear understanding of, and to practice the various embodiments. However, the scope of systems, structures and devices that may be constructed to have one or more of the embodiments, and the scope of methods that may be implemented according to one or more of the embodiments, are in no way confined to the specific illustrative examples that have been presented. On the contrary, as will be readily recognized by persons of ordinary skill in the relevant arts based on this description, many other configurations, arrangements, and methods according to the various embodiments may be implemented.
[0048] To the extent positional designations such as top, bottom, upper, lower have been used in describing this disclosure, it will be appreciated that those designations are given with reference to the corresponding drawings, and that if the orientation of the device changes during manufacturing or operation, other positional relationships may apply instead. As described above, those positional relationships are described for clarity, not limitation.
[0049] The present disclosure has been described with respect to particular embodiments and with reference to certain drawings, but the invention is not limited thereto, but rather, is set forth only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, for illustrative purposes, the size of various elements may be exaggerated and not drawn to a particular scale. It is intended that this disclosure en-compasses inconsequential variations in the relevant tolerances and properties of components and modes of operation thereof. Imperfect practice of the invention is intended to be covered.
[0050] Where the term “comprising” is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun, e.g. “a” “an” or “the”, this includes a plural of that noun unless something otherwise is specifically stated. Hence, the term “comprising” should not be interpreted as being restricted to the items listed thereafter; it does not exclude other elements or steps, and so the scope of the expression “a device comprising items A and B” should not be limited to devices consisting only of components A and B. This expression signifies that, with respect to the present disclosure, the only relevant components of the device are A and B.
[0051] Numerous other embodiments of the invention will be apparent to persons skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. | Consistent with an example embodiment, a method for preparing integrated circuit (IC) device die from a wafer substrate having a front-side with active devices and a back-side, comprises mounting the front-side of the wafer onto protective foil. A laser is applied to saw lane areas on the backside of the wafer, at a first focus depth to define a modification zone; the modification zone defined at a pre-determined depth within active device boundaries and the active device boundaries defined by the saw lane areas. The protective foil is stretched to separate IC device die from one another and expose active device side-walls. With dry-etching of the active device side-walls, the modification zone is substantially removed. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and an apparatus according to the preamble of claims 1 and 13 for loading an adapter for a printed circuit board testing device.
2. Description of the Related Art
From practical operation a method and an apparatus of this kind are known which f or each arrangement of the adapter pins uses an individual main magazine and an associated intermediate magazine and a common so-called locking packet. The selection plate is fastened to the intermediate magazine. The diameter of the holes in the main magazine, in the intermediate magazine including the selection plate and in the locking packet is smaller than the diameter of the heads and at least equal to that of the shafts of the adapter pins. The adapter pins thus hang by their heads in the main magazine, in the intermediate magazine and in the locking packet.
The procedure for transferring a first arrangement of adapter pins from a first main magazine into the adapter is as follows:
1. Transporting the main magazine filled with the adapter pins underneath the open locking packet,
2. lifting and thereby transferring the adapter pins into the locking packet by lifting them by means of a hole-free plate moved from below towards the main magazine,
3. closing the locking packet to hold the transferred adapter pins,
4. removing the main magazine that has been completely emptied,
5. transporting the empty intermediate magazine with the selection plate facing upwards beneath the closed locking packet,
6. opening the locking packet so that the adapter pins to be loaded into the adapter fall with their contact ends first through the selection plate into the intermediate magazine,
7. closing the locking packet to hold the remaining adapter pins,
8. removing the loaded intermediate magazine,
9. transporting the empty main magazine beneath the closed, partly filled locking packet,
10. opening the locking packet so that the remaining adapter pins therein fall back into the main magazine with their contact ends first,
11. removing the partly emptied main magazine,
12. transporting the loaded intermediate magazine beneath the open empty locking packet,
13. lifting the adapter pins and transferring them into the locking packet in the same way as described in step 2,
14. closing the locking packet to hold the transferred adapter pins,
15. removing the empty intermediate magazine,
16. transporting the empty adapter beneath the closed partly filled locking packet,
17. opening the locking packet so that the adapter pins therein fall into the adapter with their contact ends first,
18. removing the filled adapter.
These 18 steps are repeated using a second intermediate magazine if the adapter is additionally to be loaded by a second arrangement of adapter pins from a second main magazine.
It is an object of the invention to further develop the method and apparatus of the kind mentioned in the introduction so that the adapter can be loaded more simply and quickly and with less constructional outlay.
This object is achieved according to the invention by the characterizing features of claims 1 and 13. In this way it is possible to reduce the number of process steps from 18 or 36 to 6 or 12 steps and to use only one intermediate magazine even when loading the adapter with adapter pins in various arrangements and to dispense with the locking packet completely.
The transfer of a single arrangement of adapter pins is advantageously done by means of the following steps:
1. The empty intermediate magazine is placed on the full main magazine by relative movement in which the closing plate is arranged on the upper side of the intermediate magazine opposite the main magazine and the selection plate is arranged between the main magazine and the intermediate magazine,
2. the intermediate magazine and the main magazine are tilted together through about 180, so that the adapter pins to be loaded into the adapter fall through the selection plate with their contact heads first into the intermediate magazine,
3. the partly emptied main magazine is removed,
4. the empty adapter is placed with its side holding the heads of the adapter pins when in the loaded state by relative movement on to the side of the loaded intermediate magazine facing away from the closing plate,
5. the adapter and the intermediate magazine are tilted together through about 1801 so that the adapter pins fall into the adapter with their contact ends first,
6. the loaded adapter is removed.
If the adapter is to be loaded additionally with a second arrangement of adapter pins it is then advantageously tilted through about 90° so that it is on edge. The following steps can then ensue:
7. Repetition of the aforementioned step 1, but with a second main magazine that is loaded with the adapter pins of the second arrangement,
8. repetition of the aforementioned step 2, but with the second main magazine,
9. repetition of the aforementioned step 3, but with the second main magazine,
10. the intermediate magazine loaded with the adapter pins from the second main magazine is tilted through about 90° so that it is on edge and by relative movement is placed against the adapter, loaded with adapter pins from the first main magazine, that has already been tilted on edge--this prevents adapter pins from falling out of the intermediate magazine, which would be the case if it had been tilted through 180° to place it on the adapter located in the horizontal position after step 6,
11. the intermediate magazine and the adapter are tilted together through 90° so that the adapter pins fall into the adapter with their contact ends first and the intermediate magazine remains behind empty,
12. the completely loaded adapter is removed.
It is also possible, after transferring the adapter pins from the first main magazine into the intermediate magazine, to transfer further adapter pins that are to be loaded into the adapter from one or several further main magazines successively into the intermediate magazine with their heads first under gravity.
It is advantageous to tilt the intermediate magazine loaded with adapter pins from at least the first main magazine through about 90° so that it is on edge and, after placing it against a further main magazine likewise on edge to tilt them back together through about 90° so that the adapter pins are transferred under gravity from the further main magazine into the intermediate magazine. After removing this main magazine the aforementioned steps 4 to 6 or 10 to 12 are advantageously carried out, steps 10 to 12 being carried out analogously with an empty adapter and with the intermediate magazine loaded with adapter pins from the first and the further main magazine. Obviously the aforementioned procedure for transferring the adapter pins from the main magazine to the intermediate magazine and to the adapter, in each case by tilting them twice through 90°, can also be used to load a still empty intermediate magazine and still empty adapter with adapter pins from the first main magazine by modifying steps 1 to 6.
According to a modification of the method the adapter pins that have been transferred from at least one main magazine into the intermediate magazine can be held securely by closing a clamping device adjacent to the closing plate, whereupon the intermediate magazine with the securely held adapter pins is tilted through about 180° and placed on the adapter so that after the clamping device is opened the adapter pins are transferred under gravity into the adapter with their contact ends first. In this way the intermediate magazine can be tilted together with the adapter through 180° instead of twice through 90°.
To obtain the same advantage when transferring adapter pins of a further arrangement into the intermediate magazine, after closing the clamping device and tilting through about 180° the loaded intermediate magazine is preferably placed on a further main magazine and tilted again with it through about 180° so that after releasing the clamping device again the adapter pins are transferred under gravity from the further main magazine into the intermediate magazine with their heads first.
After this the adapter is advantageously placed with its side holding the heads of the adapter pins when in the loaded state on the side of the loaded intermediate magazine facing away from the closing plate and after closing the clamping device is tilted together with the intermediate magazine through about 180° so that after releasing the clamping device the adapter pins are transferred to the adapter with their contact ends first.
The main magazine preferably comprises at least two perforated plates arranged parallel to and spaced from one another having holes arranged coaxially at the aforementioned grid points, their diameters being smaller than the diameters of the heads and at least equal to the diameters of the shaft section of the adapter pins to be accommodated.
Similarly the intermediate magazine can likewise comprise at least two perforated plates arranged parallel to and spaced from one another having holes arranged coaxially at the aforementioned grid points with a diameter that is at least equal to the diameter of the heads of the adapter pins.
The clamping device preferably comprises a clamping plate that is arranged between the two perforated plates and that can be moved in its plane from an open position to a closed position, having holes arranged at the aforementioned grid points whose diameters are at least equal to the diameter of the heads of the adapter pins such that when the clamping plate is in its open position it holes are arranged centrally with the holes of the perforated plates and eccentrically thereto when it is in its closed position. The clamping device can be urged by a spring into its closed position.
The method according to the invention can be carried out both manually and mechanically. For this purpose a transporting arrangement is advantageous with which the main magazine, the intermediate magazine and the adapter can be transported relative to one another into positions in which the adapter pins can be transferred under gravity from the main magazine to the intermediate magazine and thence into the adapter. Advantageous embodiments of the transporting arrangement are set forth in claims 19 to 29.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail with reference to three variants of the method and two exemplary embodiments of an apparatus for carrying out the method shown in the drawings, in which:
FIGS. 1-11 show the first exemplary embodiment of the apparatus and a sequence of steps of the first method, wherein the main magazine and the adapter in FIGS. 1, 5 and 9 are shown in plan f rom above, and in FIGS. 2-4, 6-8, 10 and 11 are sectioned along the lines II--II in FIG. 1, VI--VI in FIG. 5 and X--X in FIG. 9, and the intermediate magazine is shown throughout in section,
FIGS. 12-15 show schematically a sequence of steps of the second method,
FIGS. 16-21 show schematically a sequence of steps of the third method,
FIGS. 22 and 23 show cutaway sectional views of the intermediate magazine shown in FIGS. 16-21, and
FIG. 24 shows a perspective view of the second exemplary embodiment of the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus according to the invention shown in FIGS. 1-23 includes two main magazines 1, 2 and an intermediate magazine 3 or 4 for loading an adapter 5.
The adapter 5 comprises in known manner--see FIGS. 10 and 11--three perforated plates 6.1, 6.2 and 7 which are fastened in a frame 8 in which they are held spaced f rom one another by spacer and fastening bolts 9. The perforated plates 6.1-7 are provided with through holes for receiving adapter pins 10 of a first arrangement and adapter pins 11 of a second arrangement. For simplicity both arrangements are represented in FIGS. 1-11 by only four adapter pins 10 and three adapter pins 11 and in FIGS. 16-21 by two adapter pins 10 and 11 respectively. The adapter pins of both arrangements each comprise a shaft of which one end has a head 12 and the other end is formed as a contact end. The shafts of the adapter pins 10 of the first arrangement are indicated by the numeral 13 and have the same diameter over their entire length, while the shafts of the adapter pins 11 of the second arrangement comprise a first shaft section 14.1 next to the head 12 and an adjoining second shaft section 14.2 of smaller diameter. The diameter of the first shaft section 14.1 is equal to the diameter of the shafts 13 of the adapter pins 10 which merge into contact ends 15. The contact ends of the adapter pins 11 are indicated by the numeral 16.
The holes in the perforated plates 6.1 and 6.2 are indicated by the numeral 17 and have a diameter that is smaller than the diameter of the heads 12 of the adapter pins 11 and at least equal to the diameter of the shafts 13. The holes in the outer perforated plate 6.1, like the holes 17 in the perforated plate 6.2 located beneath it, are arranged at the points of the grid of the test contact arrangement of a printed circuit board testing device (not shown) but slightly offset from one another. As shown in FIG. 11 the adapter pins 10 and 11 are arranged in the adapter 5 hanging by their heads 12 supported by the perforated plate 6.1. Their shaft sections adjacent to the contact ends 15 and 16 project through holes 17 and 18 respectively in the other perforated plate 7. The diameters of the holes 17 and 18 correspond to the diameter of the shafts 13 or to the second shaft section 14.2 of the adapter pins 10 and 11 that are respectively accommodated in them. The holes 17 and 18 are arranged partly on the grid and partly off the grid, as is shown by the slightly skew hanging adapter pins 10--second and fourth pin from the left in FIG. 11--and adapter pins 11--first pin from the right in FIG. 11--and form a hole pattern which corresponds with the hole pattern of the test contacts of the printed circuit board to be tested by the printed circuit board testing apparatus.
The main magazine 1 shown in FIGS. 2-4 is filled with the adapter pins 10 and the main magazine 2 shown in FIGS. 6-8 is filled with the adapter pins 11. Unlike in the drawing, in practice there are more holes f or receiving adapter pins in the main magazine than there are in the adapter.
Detachably fastened to the outsides of the main magazines 1 and 2 are selection plates 19 and 20 which have through holes of the same diameter but arranged in different hole patterns. The hole pattern of the through holes in the selection plate 19 corresponds to the hole pattern of the holes 17 and that of the through holes in the selection plate 20 corresponds to the hole pattern of the holes 18 in the perforated plate 7 of the adapter 5. Otherwise the construction of the main magazines 1 and 2 is identical and will be described below.
The main magazines 1, 2 each comprise four parallel plates attached to one another and having through holes that are arranged coaxially at the points of the aforementioned grid of the test contact arrangement of the printed circuit board testing device and serve to receive the adapter pins 10 and 11. Three of the perforated plates and their holes are indicated by the numerals 21.1, 21.2, 21.3 and 22 and are held apart from one another by means of fastening and spacer bolts 9. The holes 22 have a diameter that is smaller than the diameter of the heads 12 and at least equal to the diameter of the shafts 13 of the adapter pins 10. The fourth perforated plate and its holes are indicated by the numerals 23 and 14 respectively and is attached directly to the outside of the outer perforated plate 21.3. The diameter of the holes 24 is at least equal to the diameter of the heads 12 of the adapter pins 10 and 11 which, as a result of the arrangement of the perforated plates 21.1, 21.3 and 23 described above, are arranged in the main magazine 1, 2 hanging by their heads 12 accommodated in the holes 24 of the perforated plate 23 and supported by the perforated plate 21.3 located below.
The selection plate 19 or 20 is fastened directly-to the outside of the perforated plate 23 and provided with through holes arranged coaxially with the holes 24 thereof and having the same diameter and likewise having the same reference numeral 24. The number of through holes 24, however, is smaller than the number of holes 22, 24 in the perforated plates 21.1-21.3 and 23; it corresponds to the number of adapter pins 10 and 11 to be loaded into the adapter 5.
The intermediate magazine 3 shown in section in FIGS. 1-11 comprises three identical perforated plates 25.1, 25.2, 25.3 that arranged in parallel and held apart from one another by fastening and spacer bolts 9, and having through holes 26 that are arranged coaxially at the aforementioned grid points and have a diameter at least equal to the diameter of the heads 12 of the adapter pins 10 and 11. A closing plate 27 without holes is fastened detachably to the outer side of the perforated plate 25.3 by means of guide bolts 28 which extend at right angles to the plane of the plates 25.1-25.3, 27 and project beyond the perforated plate 25.1 on the side remote from the closing plate 27 by an amount that is at least equal to the thickness of the main magazine 1, 2. Bores 29 to accommodate the guide bolts 28 are made in the main magazines 1 and 2 and in the adapter 5 and, like the guide bolts 28, are arranged with respect to the holes 26 of the intermediate magazine 3, 4, relative to the holes 22, 24 and 17 of the main magazine 1, 2 and of the perforated plate 6.1 of the adapter 5, so that these holes 26, 22, 24, 17 are aligned coaxially with one another when the guide bolts 28 are accommodated in the bores 29. Guide bolts 28 and bores 29 thus represent an aligning device.
The intermediate magazine 4 shown in section in FIGS. 22 and 23 is identical to the intermediate magazine 3 except for a clamping plate 30 arranged between the perforated plates 25.3 and 25.2 and a perforated plate 25.4 supporting it. The clamping plate 30 can be moved between the perforated plates 25.3 and 25.4 from an open position to a closed position. Like the perforated plates 25.1 to 25.4 it is also provided with holes which are arranged at the aforementioned grid points and have a diameter that is at least equal to the diameter of the heads of the adapter pins 10 and 11. In the open position the holes 26 of the clamping plate 30 are central with the holes 26 of the perforated plates 25.1-25.4 and when in the closed position are arranged eccentrically thereto. The clamping plate 30 is held resiliently in the closed position by means not shown.
The method shown in FIGS. 1-11 will now be described, starting from the step shown in FIG. 1 in which the main magazine 1 filled with adapter pins 10 is arranged horizontally with the selection plate 19 facing upwards next to the empty intermediate magazine 3 which, with its plates 25.1-25.3 and 27 extending vertically, is tilted on edge through 90° relative to the horizontal. The closing plate 27 is arranged on the side of the intermediate magazine 3 remote from the main magazine 1.
Step 1: The main magazine 1 is tilted clockwise through 90° so that it is on edge, placed on the guide bolts 28 and moved along them until it abuts with the intermediate magazine 3; the main magazine 1 and the intermediate magazine 3 form the packet 1, 3 shown in FIG. 2 in which the selection plate 19 and the perforated plate 25.1 adjoin one another.
Step 2: The packet 1, 3 is tilted clockwise through 90° until it is in the horizontal position shown in FIG. 3 in which the main magazine 1 is located above the intermediate magazine 3 so that those adapter pins 10 that are in the holes 22 and 24 of the perforated plates 21.1-21.3 and 23 that are coaxial with the holes 24 of the selection plate 19 fall under gravity with their heads 12 first through the holes 24 of the selection plate 19 into the coaxial holes 26 of the perforated plates 25.1-25.3 of the intermediate magazine 3 until they abut with the closing plate 27. In this way the adapter pins 10 to be loaded into the adapter 5 are transferred from the main magazine 1 into the intermediate magazine 3; for simplicity these are only the f our adapter pins shown in FIG. 1 in heavy lines in the outer right-hand row along the line II--II. The remaining three adapter pins which are supported by the regions of the selection plate 19 that have no holes remain in the main magazine 1.
Step 3: The packet 1, 3 is tilted counter-clockwise through 90° until it reaches the position shown in FIG. 4 which, apart from the altered distribution of the adapter pins 10 between the main magazine 1 and the intermediate magazine 3, is the same as the position shown in FIG. 2.
Step 4: The partly emptied main magazine 1 is separated from the partly loaded intermediate magazine 3 by moving it along the guide bolts 28 and tilted through 90° back into the horizontal position. The partly loaded intermediate magazine 3 remains on edge. This is shown in FIG. 5 which also shows, alongside the intermediate magazine 3, the main magazine 2 filled with adapter pins 1 1 and lying in the horizontal position with the selection plate 20 facing upwards.
By steps 5 to 7 the adapter pins 11 to be loaded into the adapter 5 (for simplicity of the total of seven adapter pins these are merely the three indicated in heavy lines in FIG. 5 in the outer right-hand row along the line VI--VI) are transferred from the main magazine 2 through the selection plate 20 into the intermediate magazine 3 in the same way as the adapter pins 10 are transferred from the main magazine 1 according to steps 1 to 3, whereupon, by step 8, the main magazine 2 with the remaining four adapter pins 11 is separated from the intermediate magazine 3 just as the main magazine 1 was in step 4. The steps of the method shown in FIGS. 5-8 correspond to those shown in FIGS. 1-4. The intermediate magazine 3 loaded with all the adapter pins 10, 11 to be loaded in the adapter 5 remains on edge. This is shown in FIG. 9, which also shows the empty adapter 5 in the horizontal position next to the intermediate magazine 3 and with its perforated plate 6.1 facing upwards.
The adapter pins 10, 11 located in the intermediate magazine 3 are transferred to the adapter 5 by the following four steps:
Step 9: The empty adapter 5 is tilted through 90°, in the same way as the main magazine 1, 2, so that it is on edge and placed against the intermediate magazine 3 to form the packet 3, 5 shown in FIG. 10, in which the perforated plates 5.1 and 6.1 face one another.
Step 10: The packet 3, 5 is tilted counter-clockwise through 90° until it is in the horizontal position shown in FIG. 11, in which the intermediate magazine 3 is arranged above the adapter 5 so that all the adapter pins 10, 11 seated in the coaxial holes 26 of the intermediate magazine 3 fall under gravity, with their contact ends 15, 16 first, into the holes 17, 18 of the perforated plates 6.1, 6.2 and 7 of the adapter 5. The adapter 5 is thus loaded with all the adapter pins 10, 11 necessary for testing the printed circuit board. The intermediate magazine 3 remains behind completely empty.
Step 11: The completely loaded adapter 5 is removed from the intermediate magazine 3.
Step 12: The empty intermediate magazine 3 is tilted through 90° into the on-edge position shown in FIG. 1 whereupon the process can begin anew.
According to the variant of the method shown in FIGS. 12-15 the adapter 5 is only loaded with the adapter pins 10 of the first arrangement. The following six steps are required for this.
Step 1: The empty intermediate magazine 3 is placed with its perforated plate 25.1 on to the selection plate 19 of the main magazine 1 filled with adapter pins 10--for simplicity only four adapter pins are shown--to form the packet 1, 3 shown in FIG. 12.
Step 2: The packet 1, 3 is tilted through 180° in the plane of the drawing as indicated by the arrow A, as shown in FIG. 13, so that the main magazine 1 is arranged above the intermediate magazine 3 and,, according to the pattern of holes in the selection plate 19, half of the adapter pins 10 are transferred under gravity with their heads 12 first into the intermediate magazine 3.
Step 3: The partly emptied main magazine 1 is removed from the loaded intermediate magazine 3.
Step 4: The empty adapter 5 is placed with its perforated plate 6.1 on to the perforated plate 25.1 of the intermediate magazine 3 to form the packet 3, 5 shown in FIG. 14.
Step 5: The packet 3, 5 is tilted through 180, in the direction of the arrow A, i. e. in the plane of the drawing, into the position shown in FIG. 15 in which the intermediate magazine 3 is arranged above the adapter 5 so that all the adapter pins 10 in the intermediate magazine 3 are transferred under gravity with their contact ends 15 first into the adapter 5. The empty intermediate magazine 3 remains behind.
Step 6: The loaded adapter 5 is removed from the empty intermediate magazine 3, whereupon the method can begin anew or, after tilting the intermediate magazine 3 into the on-edge position shown in FIG. 1, the adapter 5 can be loaded with the adapter pins 11 from the main magazine 2 according to the steps 5 to 10 described above.
In the method shown in FIGS. 16-21, instead of using the intermediate magazine 3 the intermediate magazine 4 having the clamping plate 30 shown in FIGS. 22, 23 is used. The procedure is as follows:
Step 1: The empty intermediate magazine 4 with the clamping plate 30 in the opening position is placed with its perforated plate 25.1 on the selection plate 19 of the main magazine I filled with adapter pins 10--for simplicity only four adapter pins are shown--to form the packet 1.4 shown in FIG. 16.
Step 2: The packet 1.4 is tilted through 180° in the plane of the drawing as indicated by the arrow A, so that the main magazine 1, as shown in FIG. 17, is arranged above the intermediate magazine 4 and, according to the pattern of holes in the selection plate 19, half of the adapter pins 10 are transferred under gravity with their heads first 12 into the intermediate magazine 4.
Step 3: The clamping plate 30 is closed, as indicated by the arrow B in FIG. 18.
Step 4: The packet 1, 4 with the closed clamping plate 30 is tilted through 180° in the direction of the arrow A, i. e. in the plane of the drawing, so that the partly loaded intermediate magazine 4 is arranged above the partly emptied main magazine 1, as shown in FIG. 18.
Step 5: The partly emptied main magazine 1 is removed so that the partly loaded intermediate magazine 4 remains.
Step 6: The partly loaded intermediate magazine 4 with the closed clamping plate 30 is placed with its perforated plate 25.1 on the selection plate 20 of the main magazine 2 filled with adapter pins 11--for simplicity on three adapter pins 11 are shown--to form the packet 2.4 shown in FIG. 19.
Step 7: The packet 2.4 is tilted through 180, as indicated by the arrow A in the plane of the drawing so that the main magazine 2, as shown in FIG. 20, is arranged above the partly loaded intermediate magazine 4 and, according to the pattern of holes in the selection plate 20, two thirds of the adapter pins 11 are transferred under gravity with their heads 12 first into the intermediate magazine 4 until they reach the position above the closed clamping plate 30 shown in FIG. 20.
Step 8: The clamping plate 30 is moved, as indicated by the arrow B, into the open position so that the adapter pins 11 fall into the intermediate magazine 4 in the position shown in FIG. 21 in which they bear with their heads 12 against the closing plate 27.
Step 9: The clamping plate 30 is closed.
Step 10: The partly emptied main magazine 2 is removed from the loaded intermediate magazine 4.
Step 11: The empty adapter 5 is placed with its perforated plate 6.1 on the perforated plate 25.1 of the intermediate magazine 4, forming a packet 4, 5.
Step 12: The packet 4, 5 is likewise tilted through 180° in the plane of the drawing so that the loaded intermediate magazine 4 is arranged above the empty adapter 5.
Step 13: The clamping plate 30 is moved into the open position so that all the adapter pins 10, 11 located in the intermediate magazine 4 are transferred under gravity with their contact ends first 15, 16 into the adapter 5.
Step 14: The loaded adapter 5 is removed, and the empty intermediate magazine 4 is available for repeating the steps of the method.
The second exemplary embodiment of the device according to the invention shown in FIG. 24 is also suitable for both loading and unloading the adapter and has in addition to the device, described above a transporting device 40 with which the main magazine 1, 2, the intermediate magazine and the adapter can be transported relative to one another to positions in which the adapter pins can be transferred by gravity from the main magazine 1, 2 to the intermediate magazine and thence to the adapter, and from the latter back to the main magazine via the intermediate magazine.
The transporting arrangement 40 includes a moveable frame stand 41, a tilting device with a plate-shaped tilting holder 42 and a tilting bearing 43, a pivoting device with a frame-shaped pivoting holder 44 and a pivoting bearing 45, a arresting device 46, a locking device 47, an aligning device 48 and a fastening device 49.
The movable frame stand 41 includes a substantially horizontal table plate 50 which has vertical supporting arms 51 projecting beyond each of its rear corner regions. The plate-shaped tilting holder 42 is mounted by means of the tilting bearing 43 on the free ends of the supporting arms 51 so that it can be tilted substantially at right angles to its plane about a horizontally extending tilting axis. The horizontal axis runs through the center of gravity of the plate-shaped tilting holder 42, which can be held in a substantially vertical or on-edge position (see FIG. 24) by means of the arresting device 46. The arresting device 46 comprises two movably guided stop bolts which are spring-loaded to engage in and block the tilting bearing 43 on both supporting arms 51. When the arresting device is released the plate-shaped tilting holder 42 can be tilted through at least 180° and can be moved into two substantially horizontal positions.
Fixing attachments (not shown) serve to detachably fix the intermediate magazine to the plate-shaped tilting holder 42 and to fix the main magazine 1 or 2 or the adapter to the frame-shaped pivoting holder 44. The latter is linked to the edge via the pivoting bearing 45 with a horizontal pivot axis to the lower edge region of the plate-shaped tilting holder 42 located in the on-edge position and can thus be pivoted substantially at right angles to its plane from, for example, the horizontal position shown in FIG. 24 in which it lies on the table plate 50, until it bears on the tilting holder 42 located in the on-edge position. By means of the locking device 47 both holders 42, 44, together with the intermediate magazine and main magazine or adapter respectively mounted on them, can be locked together and, after releasing the arresting device 46, can be tilted together, e.g. until they reach both the horizontal positions mentioned, in one of which, in loading, the adapter pins are transferred by gravity from the main magazine 1, 2 into the intermediate magazine, or in back-loading are transferred from the adapter into the intermediate magazine. By tilting the holders 42, 44 that are locked together clockwise (looking at FIG. 24 from the left) the other horizontal position can be reached, in which the adapter pins are transferred from the intermediate magazine into the adapter when loading, or from the intermediate magazine into the main magazine when back-loading. The locking device 47 includes corresponding locking elements which are arranged on the edge regions of both holders 42, 44 opposite the pivoting bearing 45.
Clearance in the pivoting bearing and in the mounting devices is compensated by the aligning device 48 so that the holes in the intermediate magazine mounted on the tilting holder 42 and those in the main magazine or adapter mounted on the pivoting holder 44 are coaxial with one another when both holders 42, 44 are folded together and locked together by the locking device 47. The aligning device 48 comprises two diagonally opposed bores in each holder 42, 44 and two guide bolts that can be inserted in these bores which, when they are not in use, can be hung in the table plate as shown in FIG. 24.
The fastening device 49 comprises two spaced fastening strips attached to the tilting holder 42 which serve to detachably fasten the selection plate 19 or 20 to the intermediate magazine. Compared with the other possibility of fastening it to the main magazine 1 or 2, this alternative means of fastening the selection plate 19, 20 to the intermediate magazine simplifies back-loading the different arrangement of adapter pins from the adapter into the respective intermediate magazine and from the latter into the respective main magazine 1 or 2.
The apparatus according to the invention shown in FIG. 24 can be equipped with appropriate means in order to use the alternative embodiments of the main magazine and the adapter (not shown) which will now be described.
Instead of having the three identical perforated plates of the embodiment described with reference to FIGS. 1 to 11, each of the main magazines according to the alternative embodiment can have only two such perforated plates, i.e. the perforated plate 21,3 and the perforated plate 21,2 that can be moved to change its distance from the first plate. While the adapter pins are being transferred from the main magazine to the intermediate magazine as shown in FIG. 3 the perforated plate 21,2 lying on the perforated plate 21,3 is merely lifted by the aforementioned means to change the distance apart. In this way sufficient guidance of the adapter pins and thus problem-free transfer into the intermediate magazine is achieved. In the same way the perforated plate 21,2 is lifted while the adapter pins are returned from the intermediate magazine into the main magazine, but in this case to reduce the distance apart and to transfer the adapter pins with the contact ends first into the main magazine without difficulty.
In the same way the adapter according to the alternative embodiment is provided with an additional perforated plate which is identical to the perforated plate 6, 1 and can be moved so that the distance f rom it can be changed. Furthermore the perforated plates 6.2 and 7 can be removed f rom or inserted into the adapter as a unit. While the adapter pins are being transferred from the intermediate magazine into the adapter as shown in FIGS. 10 and 11, with the unit 6.2,7 inserted, the additional perforated plate is lifted by the aforementioned means to reduce the distance and thus to facilitate transfer of the adapter pins into the adapter. In the same way, while the adapter pins are being transferred back from the adapter (for which purpose the unit 6.2,7 is removed from the adapter) into the intermediate magazine the additional perforated plate is lifted, but in this case to increase the distance so that in this way sufficient guidance of the adapter pins and thus problem-free transfer thereof with their heads first into the intermediate magazine is achieved. Furthermore the device according to the invention shown in FIG. 24 can be provided with means which, for example during transfer of the adapter pins from the intermediate magazine into the adapter, make it possible to increase the distance between the intermediate magazine and adapter, likewise to facilitate the transfer of adapter pins. | There is disclosed a method for loading an adapter for a printed circuit board testing device with adapter pins having head ends and contact ends. The adapter pins to be loaded into the adapter are transferred by gravity from at least one main magazine, with their head ends first, into an intermediate magazine. Also, the adapter pins that have been transferred into the intermediate magazine are then transferred by gravity with the contact ends first into the adapter. For simpler and more rapid loading of the adapter with minimal constructional outlay, the adapter pins are transferred from the main magazine head first into the intermediate magazine. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit, pursuant to 35 U.S.C. 119(c), of Provisional Application No. 61/148,299, filed on Jan. 29, 2009, and said provisional application is incorporated herein by reference in its entirety for continuity of disclosure.
FIELD OF THE INVENTION
[0002] The present invention relates in general to means for anchoring or preventing flotation of pipelines, such as oil and gas pipelines. In particular, the invention relates to bag-type weights for large diameter pipelines.
BACKGROUND OF THE INVENTION
[0003] Weights of various types are commonly used to anchor pipelines, particularly for pipelines running through water bodies, marshes, sloughs, or other moisture-laden zones in which pipelines might be upwardly displaced due to buoyancy forces. Bag-type pipeline weights are typically made from a flexible and durable fabric or similar material, with pockets or compartments that can be filled with ballast material (such as gravel) to provide weight as needed. The filled weights are then laid over or attached to a pipeline at spaced intervals. Some known bag-type weights incorporate or require straps of sonic sort, to be wrapped and tied around the pipeline. Other designs simply rely on the ballast mass to keep the weights in place relative to the pipeline. Some known designs are configured to straddle the pipeline, with ballast-filled side lobes extending down each side of the pipeline. Bag-type weights have a particular advantage over other known pipeline weights in that they can be filled with ballast material at or near to a pipeline-laying operation, resulting in considerably lower weight transportation costs as compared to, for instance, precast concrete weights.
[0004] Examples of prior art bag-type pipeline weights may be found in the following patent documents:
[0005] U.S. Pat. No. 3,793,845 (Keith);
[0006] CA 2,075,006 and U.S. Pat. No. 5,385,430 (Connors); and
[0007] CA 2,277,523 and U.S. Pat. No. 6,220,788 (Jewell).
[0008] The problem of providing ballast for larger diameter pipelines (e.g., 16-inch plus) has particular challenges. The volume of a pipe per unit of pipe length (i.e., the cross-sectional area of the pipe) is proportionate to the square of the diameter. Accordingly, the potential buoyancy forces acting on a pipeline, per unit of pipeline length, also vary with the square of the pipeline diameter, and the ballast weight (or anchoring force) required to counteract the potential buoyancy forces is generally proportional to the square of the pipeline diameter as well. For example, the ballast weight required to weigh down a given length of 32-inch diameter pipeline will be about four times greater than for the same length of 16-inch diameter pipe (in similar service conditions).
[0009] Because of their inherent configurations, prior art bag-type weights are not suitable or readily adaptable for ballasting large-diameter pipe. For example, weights such as those taught by Jewell are not readily scalable to accommodate the much greater mass of ballast required for large-diameter pipelines. The Connors design, if scaled up to hold greatly increased amounts of ballast, will be difficult to fill, handle, and install, particularly where it is desired or necessary to install a pipeline in a trench with minimum possible side clearances.
[0010] For the foregoing reasons, there is a need for a bag-type pipeline weight design that is readily adaptable to accommodate the large volumes of gravel or other ballast material required to weigh down large-diameter pipelines. At the same time, there is a need for a bag-type pipeline weight for large-diameter pipelines that is easier to fill, transport, and install than known bag-type weight designs. Furthermore, there is a need for a bag-type pipeline weight for large-diameter pipelines that substantially retains its shape after being filled with ballast and during installation, thus facilitating its use in comparatively narrow pipeline trenches. The present invention is directed to these needs.
BRIEF DESCRIPTION OF THE INVENTION
[0011] The present invention provides a flexible bag-type pipeline weight configured to straddle a pipeline, with internal tic means for preventing excessive bulging of the weight during or after being filled with ballasting material, thus facilitating installation in comparatively narrow pipeline trenches. Built-in loading loops facilitate filling the weight with gravel or other ballasting material, without need for special loading hoppers or other complex equipment. The pipeline weight of the present invention is formed with a pair of leg sections on either side of a central, pipeline-receiving recess. Once filled with ballast, the legs remain separated, thus facilitating installation on a pipeline. The filled pipeline weight is also freestanding and stable for purposes of transport and storage prior to installation. Hoisting slings may be used to facilitate lifting and manipulation of loaded pipeline weights without the need for spreader bars.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:
[0013] FIG. 1 is a cross-section through a pipeline trench, showing a bag-type weight generally in accordance the present invention being installed over a pipeline in the trench.
[0014] FIG. 2 is a perspective view of a bag-type weight in accordance with one embodiment of the invention being positioned over a pipeline.
[0015] FIG. 3 is a perspective view of a first embodiment of the invention.
[0016] FIG. 4 is a perspective view of a second embodiment of the invention.
[0017] FIG. 5 is a perspective view of a third embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIGS. 1 and 2 illustrate a pipeline weight 10 in accordance with one embodiment of the present invention, being positioned over a pipeline P in a trench T. Pipeline weight 10 has a nominal overall width A and a nominal length B (parallel to pipeline P). Weight 10 preferably has a plurality of hoisting slings 50 which in FIGS. 1 and 2 are shown being supported by hoisting means conceptually indicated by lifting hooks H. Weight 10 is fashioned from a suitable flexible fabric or similar material, which in preferred embodiments will be a geotextile.
[0019] Tables 1 and 2 provide data relating to weights and preferred materials for non-limiting examples of embodiments of weight 10 for selected combinations of pipe size, weight width A, and weight length B.
[0000]
TABLE 1
Bag Dimensions on Pipe
Weights
Pipe Size
A
B
lb
kg
16″
36″
84″
2,500
1,134
20″
45″
96″
5,000
2,268
24″
54″
96″
5,000
2,268
30″
67″
96″
7,000
3,175
36″
81″
96″
9,000
4,080
42″
94″
96″
12,500
5,440
48″
108″
96″
12,500
5,440
[0000]
TABLE 2
Bag Material Data
Geotextile
Loading Slings
Pipe Size
Material Weight
Width
Load Rating
16″
200 g/m 2 × 2 Layers
4″
4 × 6000 lbs
20″
200 g/m 2 × 2 Layers
4″
4 × 6000 lbs
24″
200 g/m 2 × 2 Layers
4″
4 × 6000 lbs
30″
200 g/m 2 × 2 Layers
4″
4 × 6000 lbs
36″
200 g/m 2 × 2 Layers
4″
4 × 6000 lbs
42″
200 g/m 2 × 2 Layers
4″
6 × 6000 lbs
48″
200 g/m 2 × 2 Layers
4″
6 × 6000 lbs
[0020] FIG. 3 illustrates in detail the construction of one particular embodiment of a pipeline weight 10 in accordance with the present invention. In general configuration, pipeline weight 10 resembles an open-topped bag with an arch-like recess R formed in a bottom region to allow weight 10 to straddle a pipeline P, with pipeline P disposed within recess R (as shown in FIGS. 1 and 2 ). In the embodiment shown in FIG. 3 , weight 10 has an overall width A and can be considered as divided into four rectilinear sections, as follows:
a pair of leg sections 20 , each having a width E and a length B, and extending in height from a floor panel 26 , at a bottom level L B , to an upper intermediate level L 2 ; a central section 30 extending between leg sections 20 and having a width F and a length B, and extending a height H 2 from a floor panel 36 , at a lower intermediate level L 1 , to upper intermediate level L 2 ; and a top section 40 having a width A and a length B, and extending a height H 3 from upper intermediate level L 2 to a perimeter top edge 43 at a top level L T .
[0024] Each leg section 20 has an inner sidewall 23 of length B, extending a height H 1 from bottom level L B to lower intermediate level L 1 (i.e., between floor panels 26 and 36 ): an outer sidewall 24 of length B, extending from bottom level L B to upper intermediate level L 2 (i.e., a total height of H 1 plus H 2 ); and a pair of opposing endwalls 22 of width E, extending from bottom level L B to upper intermediate level L 2 (i.e., a total height of H 1 plus H 2 ). Central section 30 has a pair of opposing endwalls 32 of width F and height H 2 , which are contiguous with corresponding endwalls 22 and which extend a height H 2 from lower intermediate level L 1 (i.e., from floor panel 36 ) to upper intermediate level L 2 .
[0025] Top section 40 has a pair of opposing sidewalls 44 of which have length B and are contiguous with outer sidewalls 24 ; and a pair of opposing endwalls 42 (of width A) which are contiguous with corresponding endwalls 22 and 32 , and which extend between sidewalls 44 . Endwalls 42 and sidewalls 44 extend a height H 3 from upper intermediate level L 2 to perimeter top edge 43 at top level L T . Perimeter top edge 43 defines a top opening 45 through weight 10 can befilled with ballast material. Perimeter top edge 43 is preferably fashioned and adapted to incorporate a drawstring 47 or other suitable means for substantially closing top opening 45 after weight 10 has been filled with ballast material to a desired level, which will typically be around upper intermediate level L 2 (but in alternative configurations may be above or below that level). Since upper section 40 in typical applications will not receive a large amount of ballast material (if any), endwalls 42 and sidewalls 44 may if desired be made of a lighter material than other portions of weight 10 .
[0026] The interior of central section 30 is in fluid communication with the interiors of leg sections 20 across the region above inner sidewalls 23 between lower intermediate level L I and upper intermediate level L 2 . As well, the interior of top section 40 is in fluid communication with central section 30 and leg sections 20 across the plane of upper intermediate level L 2 . Accordingly, when a ballast material is introduced into weight 10 through top opening 45 it can flow into all four sections of weight 10 .
[0027] In preferred embodiments, when leg sections 20 are charged with ballast, inner sidewalls 23 are maintained at a substantially uniform lateral spacing from their corresponding outer sidewalls 24 by first tie means extending between each inner sidewall 23 and its corresponding outer sidewall 24 . In the embodiments shown in FIGS. 3 , 4 , and 5 , the first tie means take the form of a plurality of cables or cords 82 extending between sidewalls 23 and 24 through tie openings 81 in sidewalls 23 and 24 . Preferably, sidewalls 23 and 24 incorporate reinforcing bands 80 made of a heavy fabric or other suitable material in the region of tie openings 81 , as shown in FIGS. 3 , 4 , and 5 . The first tie means thus have the effect of maintaining sidewalls 23 and 24 generally parallel to each other after being filled with ballast, thus preventing excessive bulging of leg sections 20 and facilitating or enabling installation of weight 10 over a pipeline P in a trench T in situations where the space between pipeline P and the adjacent trench sidewall is as little as width E of leg section 20 .
[0028] To further prevent or minimize excessive bulging of weight 10 after filling, second tie means in the form of one or more crossties 60 preferably extend between central section endwalls 32 (and/or between leg section endwalls 22 , and/or between top section endwalls 42 ) at or near upper intermediate level L 2 , as shown in FIGS. 3. 4 , and 5 . Similarly, third tic means in the form of one or more lateral ties 62 preferably extend between outer sidewalls 24 of leg sections 20 (and/or between top section sidewalls 44 ) at or near upper intermediate level L 2 , as shown in FIGS. 3 , 4 , and 5 . As shown in the Figures, crossties 60 and lateral ties 62 preferably form a grid or lattice pattern, with spaces between adjacent crossties 60 and adjacent lateral ties 62 , so as to interfere as little as possible with the flow or passage of ballast material into leg sections 20 and central section 30 when weight 10 is being filled. Preferably, crossties 60 and lateral ties 62 are connected (such as by stitching or riveting) where they cross.
[0029] Preferred embodiments of pipeline weight 10 incorporate lift means preferably in the form of multiple slings 50 as shown in FIGS. 3 , 4 , and 5 . The locations, lengths, and heights of slings 50 , and the materials from which they are fashioned, may be selected and varied to suit specific configurations and installation conditions of weight 10 . Typically, slings 50 will be made from a heavy fabric or other strong and flexible material, and securely attached to weight 10 by means of stitching, riveting, or other suitable connection means, optionally in association with reinforcing bands 84 attached to weight 10 .
[0030] In preferred embodiments, weight 10 has, on each side thereof, a plurality of loading loops 70 securely attached to the inner (or outer) faces of top section sidewalls 44 (or leg section outer sidewalls 24 ) at or in the general vicinity of upper intermediate level L 2 . FIGS. 3 , 4 , and 5 show either two or three loading loops 70 on each side of weight 10 , but this is for illustration only; there is no inherent limit to the number of loading loops 70 that may be provided. Loading loops 70 may be used to facilitate the filling of weight 10 with ballast material in a number of alternative ways. In order to use loading loops 70 , endwalls 42 and sidewalls 44 of upper section 40 are bunched or folded down as necessary to expose and provide ready access to loading loops 70 . The forks of a fork lift (not shown) may then be inserted through loading loops 70 , whereupon the fork lift used to lift the empty weight 10 and position it over a pipe stub of a diameter matching that of a pipeline P over which the filled weight 10 is to be installed. The use of a pipe stub facilitates filling of weight 10 for optimal fit over pipeline P.
[0031] With empty weight 10 being suspended from the forklift, with floor panels 26 of leg sections 20 being at or near ground level (or other supporting surface), gravel or other ballast material can be introduced into weight 10 using a mobile loader or other suitable materials handling equipment. After weight 10 has been filled to a desired level, weight 10 will be free-standing on filled leg sections 20 , such that the forklift forks can be withdrawn from loading loops 70 . Endwalls 42 and sidewalls 44 of upper section 40 can then be raised as necessary to allow drawstring 47 to be tightened, thus completely or substantially closing off top opening 45 , whereupon suitable hoisting and transport equipment (e.g., wheeled loader, fork lift, or mobile crane) can be used to hoist the loaded weight 10 by means of hoisting slings 50 and to install loaded weight 10 in a desired location over a pipeline P (or to a weight storage area for later installation).
[0032] In an alternative loading method, loading loops 70 of an empty pipeline weight 10 are positioned over brackets or lugs of a suitable filling stand or frame instead of the forks of a fork lift. The weight-loading procedure is otherwise generally similar to the procedure using a forklift. After weight 10 has been filled with ballast to the required level, loading loops 70 can be removed from the filling stand so that drawstring 47 can he tightened and loaded weight 10 can be lifted out of the filling stand and moved to the installation area or a storage area.
[0033] FIGS. 4 and 5 illustrate only two of many possible hoisting sling arrangements that can be used with pipeline weights in accordance with the present invention. FIG. 4 shows an alternative pipeline weight embodiment 110 that is similar in all respects to weight 10 shown in FIG. 3 except for the location and length of hoisting slings 50 . FIG. 5 shows a further embodiment 210 that is similar in all respects to weight 110 shown in FIG. 4 except for the presence of additional hoisting slings 50 , and optional sling retainer loop 55 which can be used to gather multiple hoisting slings 50 together and thus facilitate engagement of hoisting slings 50 with crane hooks or other hoisting equipment. The components and construction details of pipeline weights 110 and 210 will be substantially identical to corresponding components and details shown in FIG. 3 , so for purposes of simplicity and clarity, reference characters are largely omitted from FIGS. 4 and 5 .
[0034] It will be readily appreciated by those skilled in the art that various modifications of the present invention may be devised without departing from the essential concept of the invention, and all such modifications are intended to come within the scope of the present invention and the claims appended hereto. It is to be especially understood that the invention is not intended to be limited to illustrated embodiments, and that the substitution of a variant of a claimed element or feature, without any substantial resultant change in the working of the invention; will not constitute a departure from the scope of the invention. For example, although the illustrated embodiments of bag-type pipeline weights are of generally rectilinear configuration in whole or in part, alternative embodiments may incorporate one or more non-rectilinear sections or portions without departing from the fundamental concepts of the invention.
[0035] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following that word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element. Any use of any form of the terms “connect”, “attach”, or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure. | A flexible bag-type pipeline weight, configured to straddle a pipeline, has internal tie means to prevent excessive bulging of the weight after being filled with ballasting material, thus facilitating installation in narrow trenches. Built-in loading loops facilitate filling the weight with ballasting material without need for special loading equipment. The bag-type pipeline weight is formed with a pair of leg sections on either side of a Central, pipeline-receiving recess. Once filled with ballast, the legs remain separated, thus facilitating installation on a pipeline. The filled pipeline weight is also freestanding and stable for purposes of transport and storage prior to installation. Hoisting slings facilitate lifting and manipulation of loaded pipeline weights without the need for spreader bars. | 5 |
This is a continuation of U.S. application Ser. No. 09/548,659, filed on Apr. 13, 2000, and now U.S. Pat. No. 7,433,845. This application claims benefit to U.S. Provisional Application No. 60/129,033, filed on Apr. 13, 1999, herein incorporated by reference.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to financial data processing and business practices regarding funds transfer. More specifically, the present invention provides a personal payment number (PPN) wherein an individual or business can receive payments from other individuals or businesses without revealing confidential account information or establishing themselves as a credit/debit card accepting merchant.
2) Brief Description of Related Art
With the increasing globalization of commerce the need for safe and secure ways to make payments between individuals, businesses and merchants now extends to systems that provide global coverage and include currency exchange systems. In addition there is a need for these systems to be secure and also to be trusted by all parties.
Existing systems such as systems based on bank checks or bank transfers involve either the payer or the payee revealing details about their bank account to at least the other party. For instance, the recipient of a check sees the payer's bank account and routing information on the check, and with a bank transfer the recipient/payee must provide their account information to the sender/payer. In a global situation where the two parties may have never have met, sharing of such information may be sufficient cause for concern to deter one or other party from proceeding. Also, different checking and bank transfer systems can reduce the effectiveness of the financial transaction.
The global credit/debit card system provides an ideal mechanism for receiving payment but under normal circumstances requires the recipient to be a credit card accepting merchant. Being a credit card accepting merchant may not be cost-effective for some people or businesses wanting receiving payments. Also smaller merchants without a good trading history may have difficulty in being accepted by credit card acquiring banks as credit card accepting merchants.
The ability to receive funds using a simple, rapid and secure system without the need to be a formal credit card accepting merchant will be of benefit to a wide range of users. For example the rise of online auction services (such as those developed by eBay and Amazon) means that many individuals may occasionally require a means of receiving finds remotely, such as over the Internet. Also, the widespread “shareware” software distribution system provides a mechanism for software written by individuals to be distributed on a global basis. Shareware authors are generally individuals that do not have the organizational support to handle global payments. Therefore a system that can provide a global payment solution with no administrative overheads with automatic currency conversion would be very attractive to these as well as many other users.
In the growing global electronic commerce environment many individuals and companies may offer their service remotely over the Internet or other public, semipublic or closed network. Such services (programming, translation, writing, clerical, accounting, web-page design, etc) will typically be provided remotely and not require any direct physical interaction between the provider of the service and the service user. The two parties to such an arrangement may never have met raising the issue of mutual trust. In addition they may be in different countries and this produces problems for currency exchange or incompatibility of bank transfer systems as well legal challenges if a non-payment dispute arises. Again a simple, rapid global payment solution would be of benefit.
The need and value of such a service is indicated by the number of systems that have already been proposed to address this issue. Examples of systems operating within this area include:
Billpoint This service acts as an intermediary between payers and payees, requiring both to sign up to the system. It is operated as proprietary system and is designed for application in the on-line auction house arena. PayPal This system is another intermediary closed system where the payer registers with PayPal and provides credit card or bank account details. When the payer wants to make a payment he transfers money to PayPal and an email is sent to the email address of the recipient with message that someone has sent you money. The recipient must then register to receive the funds by account transfer or refunded onto a conventional credit card number. Payme This system sends email bill to users through the Payme site (payee registers with “Payme”), email goes out with a request for payment. The payer pays Payme who transfers the funds to payee. eMoneyMail In this system the payee goes the eMoney website and pays with credit/debit/account transfer and gives the email address of the recipient. The recipient receives an email with a link back to the eMoney site where they can receive the funds by transfer to a checking account or credit card. Wire-transfer The provider offers a range of services offer account to account wire transfer such as Western Union and Swift. Checkfree This system is an example of a bill paying system which requires both parties to be registered with the system.
In many of the above systems the recipient must give either a credit/debit card number or bank account number to a third party (payer or other intermediary). In the case of using a credit/debit card, the payment is made by initiating a “refund” transaction even though there was no matching initial payment since the payment was made another party. There are two key problems with using this refund mechanism:
(1) Within the current card systems (such as Visa, Mastercard and Europay) there is the problem of reverse interchange. This is the process whereby a refund leads to the customer's bank (i.e., the bank who issued the credit card that is being refunded) paying back to the merchant acquiring bank (i.e., the bank that received the refund request from a credit card merchant) the interchange fee (effectively a commission) that would have been kept by the customers bank on the original payment. Since no original payment has been made in the scenario where someone is receiving money from a third party, the customer's bank (i.e., the bank who issued the credit card that is being refunded) is effectively being charged for the transaction at a cost of approximately 1.5% of its value depending on the prevailing interchange rates for the specific credit card. Under the current credit card systems, trying to change the rules for refunds to address this issue will lead to the converse problems in true refunds.
(2) In order to receive funds a user must reveal his or her actual credit card number. These details have the potential to be misused creating worry, inconvenience and potentially financial cost for the recipient. In the case of Internet payment systems, this information is then potentially stored on a server connected to the Internet. As recent fraud scares have indicated, storage of personal details in computer databases linked to the Internet represents possibly the most vulnerable security weakness with Internet based credit card transactions.
In addition, with several of above the above Internet payment services, the recipient receives an email notifying them that someone wishes to pay funds to them. The recipient then follows a link in the email to a site where he/she must enter their credit or bank account details to receive the funds. Clearly a fraudulent message offering a prize, a non-existent payment, etc., could easily lead to innocent victims giving over their credit card details which could then be misused by the perpetrator of the fraud.
SUMMARY OF THE INVENTION
These and other problems are solved by the present invention which represents a new form of credit/debit card with an associated account number that is limited so as to prevent it being used for any purchases—but instead is expressly designed for the purpose of receiving funds. In other words, the present invention involves a personal payment number (PPN) format including routing information (e.g., a BIN) to direct financial transaction information to a particular institution among a plurality of institutions on a computer network, and a unique identification of a user associated with the particular institution. The PPN format can also include an identifier identifying the personal payment number as an account to which funds can be transferred but from which funds cannot be transferred. The PPN format can follow a standard credit/debit card format, or can be unique among but follow standard credit/debit card formats or be distinct from standard credit/debit card formats. The PPN can alternatively follow a standard credit/debit card number format and omit any identifier, but the routing information be for an institution that is restricted to transactions where funds are received.
This personal payment number (PPN) can therefore be revealed without any concern for fraudulent misuse since it can only be used to receive funds and therefore is of no benefit to any other party. Any misuse would only benefit the registered cardholder. In effect it represents an inverse debit/credit card, allowing payment directly into an account rather than from an account.
To incorporate this invention with an existing credit or debit card account, a payment account number could be linked to an existing credit/debit card account so users would have a combined account with two numbers: one for making payments (the actual credit/debit card number) and one for receiving payments (the PPN or personal payment number).
The payment number could be printed on the back of an existing credit/debit card allowing for use in face to face transactions or for easy access if used over the phone or Internet. The number could also be stored within a software package (such as virtual card software) for easy use on the Internet.
Since a PPN can not be used (or misused) for making purchases it can be freely disseminated in a way similar to the way to a public encryption key is freely disseminated to allow payments to be made by anyone who needs to pay a certain person. Examples include shareware authors who could include their PPN in their software registration documentation. In on-line auction situations, sellers could email their PPN to the purchaser to allow them to complete the purchase at a payment service of their choice.
Of particular interest is the fact that a PPN could be used in place of a credit card number in the existing commercial systems named above (e.g., Billpoint, PayPal, Payme, and eMoneyMail) where the recipient receives funds by a refund onto a conventional credit card without the concerns of revealing a credit card number to a third party and its subsequent storage on an Internet accessible server.
The PPN, if it has the numerical format and verification codes (such as the checksum and cvv2) of a normal credit card, it can be processed by normal credit card terminals/software. To avoid any possible confusion with existing credit cards, an alternative would be to use a different number of digits or other differentiator. This would prevent the possibility of anyone trying to use a PPN for making a payment rather than receiving a payment since merchants and others would recognize that the PPN did not represent a valid credit card format. A possible disadvantage of specific PPN number format is that potentially less of the existing credit card infrastructure could be used leading to increased up-front investment costs for implementation of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages, features and aspects of the present invention shall now be described by way of exemplary embodiments to which the present invention is not limited with reference to a accompanying drawing figures in which:
FIG. 1 shows an exemplary system for implementing the present invention;
FIG. 2 shows an exemplary personal payment number format implementing the present invention;
FIG. 3 shows, in high-level form, the operation of the central processing station shown in FIG. 1 ;
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In this specification the terms “credit card” and “credit/debit card” refers to credit cards (MasterCard®, Visa®, Diners Club®, etc.), charge cards (e.g., American Express®, some department store cards), debit cards such as usable at ATMs and many other locations or that are associated with a particular account, and hybrids thereof (e.g., extended payment American Express®, bank debit cards with the Visa® logo, etc.).
Various aspects of the invention may be embodied in a general purpose digital computer that is running a program or program segments originating from a computer readable or usable medium, such medium including but not limited to magnetic storage media (e.g., ROMs, floppy disks, hard disks, etc.), optically readable media (e.g., CD-ROMs, DVDs, etc.) and carrier waves (e.g., transmissions over the Internet). A functional program, code and code segments, used to implement the present invention can be derived by a skilled computer programmer from the description of the invention contained herein.
Exemplary System Implementation
FIG. 1 shows an exemplary overview of a system for implementing the limited-use credit card system of the present invention. Further details of similar systems can be found in co-pending U.S. application Ser. No. 09/235,836 filed on Jan. 22, 1999 and 09/506,830 filed on Feb. 18, 2000, herein incorporated by reference. The system 100 comprises a central processing station 102 , which, accordingly to exemplary embodiments, may be operated by the credit card provider. Generally, this central processing station 102 receives and processes remotely generated credit card transactions. The credit card transactions can originate from a merchant in a conventional manner, e.g., by swiping a credit card through a card swipe unit 106 . Alternatively, the credit card transaction requests can originate from any remote electronic device 104 (e.g., a personal computer). These remote devices 104 can interface with the central processing station 102 through any type of network, including any type of public or propriety networks, or some combination thereof. For instance, a personal computer 104 can interface with the central processing station 102 via the Internet 112 . Actually, there may be one or more merchant computer devices (not shown) which receive credit card transactions from the remote electronic device 104 , and then forward these requests to the central processing station 102 . The central processing station 102 does not have to be in one geographic location. Instead, it can be embodied as a credit card transaction network which routes transaction information to specific card issuing institutions by, e.g., a bank identification number (BIN). Here it should be noted that a single bank can have several BINs, each of which would be considered an institution of purposes of this disclosure. The central processing station 102 can also interface with other types of remote devices, such as a wireless device 140 (e.g., cellular telephone), via radiocommunication using transmitting/receiving antenna 138 .
The central processing station 102 itself may include a central processing unit 120 , which interfaces with the remote units via network I/O unit 118 . The central processing unit 120 has access to a database of credit card numbers 124 , a subset 126 of which are designated as being available for use as personal payment numbers.
Also, the central processing unit 120 has access to a central database 122 , referred to as a “links” database. This database is a general purpose database which stores information regarding customers' accounts, such as information regarding various links between each customer's PPN and his or her regular credit card account or other type of account using, for instance, some type of linked-list mechanism. Databases 122 and 124 are shown separately only to illustrate the type of information which may be maintained by the central processing station 102 ; the information in these databases can be commingled in a common database in a manner well understood by those having skill in the data processing arts. For instance, each PPN can be stored with a field which identifies a regular account to which it is linked, and various conditions regarding its use. It should be noted that no discernable relationship should exist between the PPN and the regular credit card number. Also, the different databases can be addressed using different BIN numbers or different number formats or other identifiers in the PPN number.
The central processing unit 120 can internally perform the approval and denial of transaction requests. For the PPN, if the transaction does not involve transferring funds into the PPN account, the transaction would be denied. For credit transactions, the approval or denial by making reference to credit history information and other information in the conventional manner. Alternatively, this function can be delegated to a separate clearance processing facility (not shown).
Finally, the central processing station includes the capability of transmitting the PPN to customers. In a first embodiment, a local card dispenser 128 can be employed to generate a plurality of PPN cards 132 and/or credit cards 134 additionally bearing a PPN for delivery to a customer. In another embodiment, the PPN can be printed on a form 136 by printer 130 , which is then delivered to the customer via the mail. The PPN can be included in the initial letter distributing an associated credit card, or in a monthly or other periodic account statement sent to the customer. In yet another embodiment, the PPN can be electronically downloaded to a user's personal computer 104 , where they are stored in local memory 142 of the personal computer 104 for subsequent use. In this case, the PPN can be encrypted, but concern over release of the PPN is much less than for regular credit card numbers. Instead of the personal computer 104 , the numbers can be downloaded to a user's smart card though an appropriate interface. In a still further embodiment, the PPN can be downloaded to a radio unit 140 (such as a portable telephone) via wireless communication. In another embodiment, an ATM 108 can be used to dispense the PPN cards 110 . Those skilled in the art will readily appreciate that other means for conveying the PPN numbers/cards can be employed. These embodiments are, of course, usable together.
The logic used to perform the PPN transactions preferably comprises a microprocessor which implements a stored program within the central processing unit 120 . Any general or special purpose computer will suffice. In alternative embodiments, the logic used to perform the PPN transactions may comprise discrete logic components, or some combination of discrete logic components and computer-implemented control.
Personal Payment Number Format
Within the VISA and Mastercard systems, for instance, the first 6 digits of a credit card number represent a code (Bank Identification number or BIN) to identify both the issuing institution and are also used to define the associated charges (interchange fees) that are automatically made for each transaction. Other credit card systems use a similar procedure and card number format. A card issuing bank will typically have several BIN's, one for each different card products that attract different interchange rates. By allocating PPN's within a BIN that is used exclusively for PPN's, no payments can be made in that BIN. Therefore the interchange fees can be adjusted to make them appropriate for this sort of payment (ideally attracting zero or negative interchange).
This is in contrast refunding a conventional card account number leads to inverse interchange being charged to the card holder's bank as discussed above. In this situation, the card holder's bank is effectively subsidizing whichever merchant/acquirer handles the refund and has no effective means of control over this transaction and the associated costs. Although these distinctions make little difference to the holder of a PPN, they are of great relevance to the banks since they have a direct impact on the income from their credit card portfolio.
Thus, a personal payment number format includes routing information (e.g., BIN) 201 to direct financial transaction information to a particular institution among a plurality of institutions using a computer network, such as shown in the exemplary embodiment of FIG. 2 . The PPN format also includes unique identification 202 of a user associated with the particular institution. The personal payment number identifies an account into which funds can be transferred but from which funds cannot be transferred.
This identification of the account as being a payment only account can take on several forms. For instance, the personal payment number format can include an identifier 203 identifying the personal payment number as an account into which funds can be transferred but not from which funds can be received. The position of this identifier 203 within the PPN format could be arbitrary or selected according to factors outside the scope of this invention. Alternatively, the identifier 203 can be omitted and the routing information 201 (e.g., BIN) can identify an address associated with accounts limited to receiving funds and not capable of transferring out funds.
The format of a PPN should ideally be of a format that is compatible with the existing credit/debit card numbering format which is usually 16 digits with a current maximum of 19 digits for the account number field within the industry standard transaction messaging protocols. The PPN should also have a valid checksum to ensure that it is transmitted without problems through existing networks which may include checksum validation. An expiry date should be provided and additional verification codes such as the cvv2 code if required to ensure compliance with existing networks.
A PPN specific coding format could be used to prevent confusion with existing credit cards but this would reduce the compatibility with the existing credit card systems requiring additional investment to implement the system. A compromise would be for the PPN to deviate from an existing format sufficiently to allow easy recognition that it is not a normal credit card number while still allowing transmission in the data fields of the transaction messaging systems that would normally hold the credit card number, for example for VISA cards 17 or 18 digits could be used to differentiate from the existing 16 digit credit card format, such as shown in FIG. 2 .
In other words, the personal payment number can be formatted in accordance with standard credit/debit card formats. It can also be formatted to be distinct from standard credit/debit card formats, which might require some adjustment to the conventional credit transaction processing system. Alternatively, the personal payment number can be formatted to be unique among standard credit/debit card formats but remain within the acceptable standards for processing within the conventional credit transaction processing system. For instance, it can have an extra number which is acceptable to the credit transaction system, but not currently used by card issuing institutions. Also, the personal payment number format can include a verification code such as a checksum number and a cvv2.
The PPN Uses and Processes
A PPN can be used in a variety of ways. After a transaction is begun by accessing a web site or the like a PPN account holder can transmit the number (even by insecure means such as email) along with an electronic invoice requesting payment for goods/services provided. A PPN can also be included in the documentation or program code of a shareware or “try before you buy” software package. In this was the payee does not have to make any active step to receive funds, the person registering/purchasing the software simply uses the PPN to make the payment at an appropriate registration site. A PPN could also be displayed within a webpage.
In many current systems such as Billpoint the recipient receives an automated email from the payment system website when a payment is made. It is only when the recipient registers with the payment company that credit card or account details are given. Under these circumstances it possible that the email could be intercepted and someone other than intended recipient collects the funds. With a PPN payment, the payer can optionally verify the name linked to the PPN at a time of making a payment (Step 303 ) thus ensuring that the correct person is being credited. Alternatively banks could provide an authorized directory to allow payers to obtain a person's PPN, a form of PPN escrow.
Implementation Components
Implementation of the PPN solution includes a system and process comprising the following exemplary components:
User Request Handling Process, PPN Allocation System, PPN/Primary Account Database Storage, Secure PPN Database Query Interface, PPN Distribution, User Storage and Access Device(s) and Systems, PPN Transaction Initiation Device(s) and Systems, PPN Transaction Routing Network, PPN Processing System, and Customer Service System.
These components are taken in turn for more detailed descriptions.
User Request Handling Process (Step 301 )
Users can request a PPN from their bank or a bank can automatically allocate and distribute a PPN to all its account holders. During this process the bank logs details such as the account name, the PPN and the associated account in which funds are to be lodged. The options for the receiving account include a credit card account, a debit card account, free-standing bank account or other suitable account. It is important that the bank authenticates the user during this process to prevent people assuming the identity of others in order to receive funds fraudulently.
The request for a PPN can be received by the bank as an in-branch request, phone request, mail-in request, fax request or via an electronic network such as the Internet or digital TV. All these request avenues should feed into a single logging system to allow these requests to be processed appropriately.
An applicant can request a PPN account from a financial institution either in association with an existing credit/debit card/bank account, or as a standalone payment instrument (i.e. where the user's credit cards and bank accounts are held with another financial institution). In the former case the financial institution already has account information available as to where to forward the monies received, the user need only specify which account he/she wishes to use. In the case of a stand alone account the user must provide details of where the funds are to be transferred. The request can be handled by any normal route (in bank branch, by post, fax phone or by electronic network such as the Internet).
PPN Allocation System (Step 302 )
The PPN allocation system handles requests for a PPN. During this allocation the system provides a valid PPN account number.
The allocation system ensures that there is no reversible numerical relationship between the PPN and an associated credit/debit card in order to ensure that the real credit/debit card number cannot be derived from the PPN. In addition the allocation system must check the availability of a PPN before issue to ensure that each issued PPN is unique. The leading digits of the PPN must be defined in order to route the PPN to the processing center appropriate for each issuing bank, in the existing credit card systems this is achieved with the use of BIN number (usually the leading 6 digits).
PPN/Primary Account Database Storage (Step 303 )
Following the registration and allocation process, details of the allocated PPN and associated credit/debit card or other account details need to be logged in a database ( 122 and 124 , FIG. 1 ) in order to support a variety of the other systems listed below such as the processing system, the PPN query system and customer service. The name of the account holder and other personal details may be held according to the policy of the PPN issuing bank. This system is secured from unauthorized external access since it contains sensitive financial services information. For maximum data integrity a single database could service all these different functions. Alternatively a number of interlinked databases could be used if the registration allocation system were geographically remote from the processing system or these functions were handled by different organizations. In the case of multiple databases additional controls would be used to reconcile information held across all the relevant databases.
Secure PPN Database Interface (Step 304 )
An interface allows database queries, for example to request a PPN for a specific individual or to verify that a PPN belongs to a specific person. This function allows for the payer to ensure that the PPN belongs to the intended recipient and the number has not been altered or wrongly recorded at any point. The system could be used as a trusted source of PPN numbers as a form of PPN escrow. Alternatively for increased privacy a user could be required to enter the PPN and a name and be informed only if the match is correct or incorrect. A PPN holder may request for this service to be disabled if they wish for complete anonymity. This latter option will be provided only at the discretion of the issuing bank.
It is important to prevent unauthorized access to or alteration of credit/debit card or other personal details information of PPN holders held in the database. Therefore this database access system is highly secure and only allow specific types of requests by application of appropriate industry standard security and “firewall” technology. The database must however allow the bank and or the PPN holder (with appropriate authentication) to update information in the database if the PPN holder wishes to alter the status and stored attributes of the PPN account.
This database should also provide means for review of both PPN holders and the issuing bank of all transactions details. Access to this function can be via the customer service system or by the provision of a direct software connection to the database for example using software that the PPN holder obtains from his bank or using a standard browser interface.
PPN User Storage and Access Device(s) and System(s) (Step 305 )
A range of PPN user storage and access devices can be used and the choice of the most appropriate format will depend on how the user intends to use the system. The user could simply be notified of the PPN number by letter or by the issuing a paper certificate, as explained above ( 136 , FIG. 1 ). The PPN can be issued on its own physical plastic (or other suitable material) card ( 132 , FIG. 1 ) that is marked so as to ensure that it cannot be mistakenly used for purchases. Such a card could carry a magnetic stripe containing the appropriate information to allow for payments to be made on a standard terminal. The PPN could be issued on a smart card carrying a chip containing the appropriate information/certificates to allow for payments to be made on a smart card enabled terminal. Alternatively it could be printed on the reverse of an existing card ( 134 , FIG. 1 ). In this way a bank could issue a PPN to all its existing customers in a simple and cost effective way during card renewals.
The PPN can also be provided encoded in a software package that can be accessed by the user as required. The PPN could also be stored remotely by the issuing bank with the user accessing the number as required while connected to an electronic network (Internet, digital TV etc) using a browser or software designed for this express purpose ( 142 , FIG. 1 ). Such access could use the above database access system. These systems could also provide for the automatic transfer of the PPN to a website or other recipient via email, or ATM or wireless set ( 108 , 140 , FIG. 1 ) as explained above.
PPN Transaction Initiation Device(s) and System(s) (Step 306 )
Mechanisms are also required to initiate payments via a PPN. The account holder could register the PPN within a third party system electronic payment system such as PayPal, etc. and the system could then operate normally while providing extra security because the third party system electronic payment system does not hold actual bank or credit card details. In this scenario, payment would be made by whatever mechanism the system supports. Money would be transferred to the PPN as credit card refund. Such a refund could be handled by existing credit card terminals or transaction processing software if the PPN conformed to the standard credit card number format. When this transaction reaches the issuing bank it is remapped to transfer the funds either to the users own credit card account or directly to a bank account.
In addition banks could implement their own specific systems and devices for handling PPN payments. Such systems could add additional features such as PPN recipient verification, extraction of appropriate fees at source, allowing PPN holders and payers to check/review prior payments/receipts and provision of a digital receipt for the payer/recipient in the case of later disputes.
In the case of a PPN system using its own numerical format that deviated in some respects from standard credit formats, specifically modified transaction devices/software may be required to recognise and validate the PPN format before initiating the transaction.
PPN Transaction Routing Network (Step 307 )
A PPN transaction once initiated would be transferred through the credit card networks typically involving transmission to a merchant acquiring bank and then onto the issuing bank either directly or via the existing card associations (e.g., VISA, Mastercard or Europay etc.) networks, collectively referred to and the central processing station 102 in FIG. 1 . Inclusion of appropriate leading digits in the PPN will ensure that the existing global credit cards systems will automatically route the PPN transaction to the appropriate processing center as is the case with conventional refund transactions.
In the case of a PPN system using its own numerical format that deviated in some respects from standard credit formats, modifications to the existing systems may be required. Ideally from a commercial stand-point the PPN format should be capable of routing through the existing credit card networks even if it deviates from the standard format. Therefore in determining the appropriate number format for the PPN, the ability of the existing systems to transparently handle such a format is of key importance.
PPN Processing System (Step 308 )
On receipt of a PPN transaction the processing system completes some or all of the following processes:
Validate that the received PPN is a valid and issued number, Identify the appropriate associated customer account details, Determine how funds are due to be forwarded for this customer and obtain required account numbers (e.g. credit/debit or bank account details), Make appropriate deductions in the case where the bank is charging a commission or other service fee to customers for this service. Create appropriate transaction messages incorporating the forwarding account details and the adjusted amount for the fund transfer to be completed by existing bank systems. Log transaction details in a database for auditing and customer service purposes, etc. Forward the new or modified transaction messages onto the appropriate systems for completion. These systems may be the existing credit/debit card processing systems or direct electronic fund transfer systems. In specific circumstances the processing system may be configured to hold/defer payments for a specific period or until additional confirmation is received that the transaction can proceed. This option may arise in the case of suspicious transactions, as a method for the bank to fund the system by gaining interest on the held funds or when payment is made contingent upon the delivery of specific goods and services. When required the processing system should be able to initiate a reversal of a payment in order to correct for inaccurate or inappropriate payments.
Customer Service System (Step 309 )
The customer service system provides the bank with a means to monitor activity and transactions with the PPN processing system. This will include assessing the state of the PPN processing system and initiating database queries for completed transactions. The need for this service arises from the need for monitoring by the bank and to handle customer queries regarding specific PPN transactions.
Integration with Existing Payment Services
For PPN systems using existing credit card formats, the system will be compatible with any system that currently provides for payment onto a credit/debit card.
Banks that issue PPN accounts could provide a specific payment portal/website that would operate for their own or any other banks PPN. This has the benefit that the payer can choose a site that he trusts on the basis of a well known name or potentially his/her own bank even if he/she does not have a PPN account. The recipient therefore does not have to dictate to the payer that the payment is made on a specific site (one that the payer may not previously have known). Such a site can provide enhanced PPN services. These services could include providing verification that a specific PPN was associated with the intended payee, email notification by the PPN holder of a payment and provision of a digital receipt signed by a certificate authority for use in case of a dispute. Payment from the payer can be initiated as a bank transfer or credit card payment or other suitable remote payment mechanism. The funds could then be transferred to the PPN by initiating a credit card refund transaction using the PPN and existing credit transaction handling hardware or software. This site can, under terms agreed with both parties, extract commission for the transaction from either the vendor or the purchaser. This would most commonly happen in association with online auction sites. To extract commission from the purchaser, the transaction website adds a specified amount or percentage to the transaction. To extract commission from the vendor a specific amount is deducted from the transaction prior to completing the transfer of funds to the payment number's account.
Transaction Cycle
Once the payment site receives the PPN, a standard type credit card refund transaction message is created, typically for refunds within a settlement message file, containing the PPN, transaction amount and other required information. The credit card networks will route the information contained within the transaction messages according to the leading digits of the payment number in the same manner as an existing credit card transaction. This will be routed on the basis of a specific BIN (i.e. Bank Identification Number such as the first six digits in a VISA format number) to a dedicated processing server which will verify the validity of the payment number and use a database to identify the appropriate receiving account.
With a credit card format compatible PPN, funds transfer will be handled by the existing settlement systems with funds being transferred to the PPN issuing bank from the card scheme and recovered by the scheme from the merchant acquirer bank and from there from the originating payment site which acts as a credit card merchant. In the case that the acquiring bank and issuing bank are the same institution or have a bilateral agreement then the funds transfer may be made without reference to the card scheme networks.
Implementation of Location of System Components
In terms of location of the system, it could be implemented within a bank's internal credit card processing system. If a dedicated BIN (i.e. 6 digit header in VISA and Mastercard systems) is used then the credit card networks will direct all transactions to the required processing site. The software receiving the transaction information would validate the PPN number, determine the matching account details and then use standard existing networks to effect the payment.
The service could also be offered on a bureau basis whereby the PPN transactions of wide range of banks would be directed to a single site operated on behalf of all the banks. Provided this site had access to the account details of each PPN holder and access to the banking/credit card payment systems, such a single site could operate such a service for many banks. This service could allow banks to handle their own PPN allocation and then inform the central service of the number. Alternatively the entire process could be centralized with the bureau service hosting the allocation system. In this option, banks would when handling a request for a PPN request a PPN from the central system and provide the other required account details at the same time.
Such a bureau solution could be operated by the card scheme themselves providing a global service from a single site. In this situation the central site could provide for remapping the received PPN to the matching credit/debit card and forward the transaction/settlement messages onto the appropriate institutions for completion of the transaction. The interchange fees contained within the settlement messages would inherited from the original message to maintain the PPN specific interchange fees rather than the interchange associated with the receiving account. In this scenario the banks would receive standard refund transactions on a credit/debit card number and can process these entirely as normal without the financial costs associated with reverse interchange. Alternatively the central system could also provide for direct transfer of funds to a users bank account without the need for further use of the credit card systems, instead linking directly into the electronic funds transfer systems.
Alternative Implementation
In the above description the transaction website (effectively a web merchant) initiates the purchasing transaction on behalf of the payer and transmits the required information for the payment transaction for processing by the payment card processing software center. In this scenario the payment from the payer and the payment to the recipient are separate transactions.
An alternative is for both the PPN and the purchasing credit card number to be transmitted within appropriate fields within the financial message that is transmitted back for processing, with the PPN being used as the primary account number to ensure appropriate routing of the transaction message. In this scenario the payment and receipt of funds are linked and conducted by a party within the banking/credit card system rather than at the merchant level. This has the advantage that the payers details can be logged along with the PPN transaction to allow for easier transaction audit. Under these circumstances the required processing for both making and receiving the payment could be initiated at several levels, either at the level of a credit card merchant acquirer bank, within the card scheme systems or following routing from a merchant acquirer to a card processing system. Within these systems the purchasing and payment transaction can then be executed either within the same system (i.e., merchant acquirer or by processing system) or be divided between the two systems. Completion of the transaction will require one of these two systems to initiate a standard credit transaction effectively acting as a merchant and receive payment on behalf of the purchaser or to receive funds from the payer using an alternative payment system. An appropriate fund transfer (or credit to a credit card account) is then made to the payee. Pre-agreed commissions can be added to the purchase amount or deducted from payment amount in the course of the transaction. A negotiated commission can be paid to the website/merchant that initiated the transaction and transmitted the information into the credit card networks. This can be done in an independent settlement process or by direct bank transfer since the merchant is identified within the financial message format as described above.
The PPN has a number of highly positive features such as:
(1) PPN can be used in situations where revealing a credit card number would be considered potentially risky.
(2) The interchange fees associated with normal transactions can be modified to be appropriate for receiving payment rather than making payment. This allows for person to person payments without impacting on the processing of true refunds.
(3) The existing global credit card networks can be used to handle the payment providing a trusted established system.
(4) Currency exchange is handled automatically by the card networks.
(5) In order to receive payment, the PPN holder does not need to reveal bank account or credit/debit card details to anyone other than his own bank or credit card company.
It will be appreciated that the present invention is not limited to the foregoing exemplary embodiments. Variations and modifications will occur to those skilled in the art without departing from the scope of the present invention as described in the claims appended hereto. | The delivery of a secure method and system of generating person to person, business to business, business to person and person to business transactions involving transfer of funds from one party (the purchaser) to a second party (the vendor). The functionality of existing credit/debit cards and the associated infrastructure is extended to provide a secure global mechanism for individuals/businesses to receive funds without revealing confidential information or having to become credit/debit accepting merchants. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/597,461, “DEVICE FOR ISOLATION OF ELECTRICAL COMPONENTS” filed on Dec. 4, 2005, and hereby incorporated by reference.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to apparatus for isolation of cables, adapters, power sources, and electronics.
[0004] 2. Background Art
[0005] Electrical devices have become nearly ubiquitous in modern society. As technology continues to evolve, more and more electrical devices are purchased and used by consumers in homes, offices, and other environments. By definition, such devices require an electrical power source to operate. Typically the electrical power source will provide power to electrical devices through one or more cables.
[0006] Furthermore, many of today's electrical devices will also be configured to communicate with other devices. This communication is also typically achieved through the use of cables.
[0007] Although cables are an effective means of transmitting power and/or data signals, they are also vulnerable and hazardous. For instance, where cables are disposed in areas in which contact with an individual or creature or possible, the cable, individual or creature, and connected equipment are all subject to damage due to potential interactions. Furthermore, signal and power transmission through cables may adversely affect nearby equipment. Finally, unintended interactions with cables and other electrical components may result in loss of power to one or more components, with possible undesirable consequences. Accordingly, there is exists a need for a cost-effective device that can provide a desired degree of isolation for such cables, adapters, power sources, and other electrical devices.
SUMMARY OF INVENTION
[0008] In one embodiment, the invention comprises a device for providing a degree of isolation for one or more electrical components and/or other potentially hazardous and/or fragile objects. The device includes a front and base member and may also include one or more side members, as well as retaining elements disposed for retaining the electrical components in a desired location within the device.
[0009] In one embodiment, the invention comprises a method for manufacturing a device for providing a degree of isolation for one or more electrical components and/or other potentially hazardous and/or fragile objects.
[0010] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 shows one embodiment of the invention, including retaining elements disposed within an internal environment thereof.
[0012] FIG. 2 shows one embodiment of the invention, wherein the front member comprises multiple sub-members.
[0013] FIG. 3 shows one embodiment of the invention, wherein the front member comprises multiple sub-members.
[0014] FIG. 4 shows one embodiment of the invention, wherein the front member comprises multiple sub-members, one of which has a curved configuration.
[0015] FIG. 5 shows one embodiment of the invention in use with a plurality of electric components.
[0016] FIG. 6 shows one embodiment of the invention in use with a plurality of electric components.
[0017] FIG. 7 demonstrates how one embodiment of the invention might be used to provide relative isolation to a wall outlet.
[0018] FIG. 8 shows one embodiment of the invention wherein a front member is movable relative to a base member.
[0019] FIG. 9 shows one embodiment of the invention, comprising a plurality of openings.
[0020] FIG. 10 shows one embodiment of the invention, comprising at least one side member.
[0021] FIG. 11 shows one embodiment of the invention, comprising a plurality of slots for the passage of cables and other objects.
[0022] FIG. 12 shows one embodiment of the invention, configured to be operatively connected to a wall or other partition.
DETAILED DESCRIPTION
[0023] As used herein, the term “isolation” means an increased state of physical, thermal, magnetic, and/or other form of separation between an object and another object or an environment. Isolation may occur through the provision of a physical barrier and/or the provision of a magnetic, thermal, and/or electrical barrier. “Relative isolation” refers to any change in a level of isolation. Other meanings of the term “isolation” which are not incompatible with the spirit of the invention may also apply. Furthermore, other meanings of the term “isolation” may be implicit in the following description.
[0024] As used herein, “electrical component” means any thing known in the art to carry and/or utilize an electrical signal. Thus, anything that conveys, stores, and/or utilizes electrical power, data, and/or other signals falls within the scope of this term. Such things include, but are not limited to, power outlets, surge protectors, adapters, modems, computers, and cables. Other definitions which do not depart from the spirit of the invention may also apply.
[0025] As shown in FIG. 1 , in one embodiment the invention comprises a front member 102 and a base member 104 . The front member 102 is operatively connected to the base member 104 . The operative connection between the front member 102 and base member 104 may be of any type known in the art, and the two members 102 , 104 may be formed as a single unitary body. The operative connection between the front member 102 and base member 104 may be configured such that the front member 102 is disposed at any desired angle with respect to the base member 104 , and furthermore may be configured to provide a variable angle (e.g., hinged, etc.) or to be reversible.
[0026] The base member 104 may be of any desired configuration, and need not conform with the front member 102 in terms of depth, width, material, thickness, and/or any in any other fashion. In one embodiment, the base member 104 will have an increased weight to provide an increased stability. In one embodiment, the base member comprises an outlet strip, surge protector, or other electrical component.
[0027] In one embodiment, a bottom surface of the base member 104 will be configured to provide an increased stability on a predetermined substrate. For example, the bottom surface may be coated with a non-skid or cushioning material to prevent undesired displacement.
[0028] In one embodiment an upper surface of the base member 104 will be configured to retain, stabilize, and/or protect one or more objects expected to be disposed thereupon. For example, such a surface may be coated with or comprise a non-skid material, cushioning material, magnetically and/or electrically-shielded material, etc., and may also include one or more retaining elements or connectors therefore, for maintaining a desired position or configuration of objects disposed thereupon. Such objects may include electrical equipment, cables, surge protectors, electrical outlets, modems, and/or any other items.
[0029] The base member 104 may also include one or more holes, which may be threaded to operatively connect a retaining element. As used herein, “retaining element” is used generically to mean any element that is used to fix a component to a surface or to support a component in a relatively fixed location relative to an operatively connected surface. Retaining elements may include, but are not limited to, screws, bolts, clips, supports, slots, flexible ties, adhesives, and any other elements or combinations thereof having a similar functionality. Other members may also be configured to operatively connect to retaining elements.
[0030] Furthermore, it may be desirable in certain embodiments to configure a bottom surface of the base member 104 such that it is easily slideable, such that when placed on a substrate it may be more easily positioned. One or more wheels may be operatively connected to the base member 104 to facilitate positioning. In one embodiment, the base member 104 may comprise and/or be coated with a material which will facilitate sliding on a predetermined surface. One or more edges of the base member 104 may also be tapered or otherwise configured such that objects may be disposed upon an upper surface thereof by sliding the base member 104 under any such objects. For instance, the base member 104 may include a tapered edge for sliding under objects disposed on a surface along which the base member 104 is moved.
[0031] In one embodiment, it may also be desirable to dispose one or more feet or other such elements on a bottom surface of the base member 104 such that it is elevated and/or stabilized. Elevation of the base member 104 may advantageously allow for greater ventilation, particularly if one or more openings are included in the base member 104 . Such openings, in addition to providing ventilation, may advantageously function as points for operatively connecting retaining elements 107 .
[0032] As shown in the embodiments of FIGS. 2-3 , the front member 102 may comprise any number of facets and/or sub-members 106 . Any number of sub-members 106 may be used and the operative connection between sub-members 106 , and between sub-members 106 and other members, may be of any type known in the art. Furthermore, The operative connections between sub-members 106 may be of any type known in the art, including but not limited to, formation as a unitary body and hinged and/or reversible connections. Furthermore, each sub-member 106 may be disposed at any angle relative to any other sub-member 106 .
[0033] As shown in the embodiment of FIG. 4 , sub-members 106 may also have curved surfaces (in any desired dimension). The surfaces of any one or more members 102 , 104 and/or sub-members 106 may also include a decorative design and/or may include openings for ventilation, for operatively connecting retaining elements, and/or for entry and/or egress of desired objects.
[0034] In various embodiments, one or more desired members 102 , 104 , and/or sub-members 106 , may include heating and/or cooling elements. Such elements include, but are not limited to, fans. For example, in one embodiment, a fan may be operatively connected to an inner surface of a front member 102 , such that warm or cool air may be displaced by the fan through one or more openings in the front member 102 . Such a configuration advantageously provides heating or cooling to the external environment, and may also advantageously provide ventilation to components located within the internal environment.
[0035] An outer surface of a front member 102 or any sub-member 106 may also include “comfort elements” such as protrusions, dimples, rollers, cushions, or other elements known in the art such that, if positioned in front of a chair, such a surface may advantageously function as a comfortable footrest.
[0036] As shown in the embodiment of FIG. 5 , in use the invention provides a barrier between an internal environment 108 , to provide a desired type and degree of isolation from an external environment 110 . This isolation advantageously permits the placement of relatively delicate and/or potentially hazardous objects in the internal environment 108 to protect them from factors in the external environment 110 and/or minimize hazardous interactions between them and objects and/or creatures in the external environment 110 . Electrical components, such as electrical outlets, outlet strips, surge protectors, modems, adapters, and/or other electrical devices 112 and/or cables 114 may benefit from such isolation. In use, disposing embodiments of the invention near a wall 116 or other partition, advantageously provides greater isolation of the internal environment 108 .
[0037] As used herein, inner surfaces will face the internal environment 108 , in use. As shown in the embodiment of FIG. 6 , one or more inner surfaces of any member may be configured to retain one or more objects in a desired position. Any approach known in the art may be used to retain such objects in any one or more desired locations. Such approaches include, but are not limited to, retaining elements 117 .
[0038] As shown in the embodiment of FIG. 7 , the invention may be advantageously used to provide relative isolation of cables 114 , wall outlets 118 , and/or other potentially fragile and/or hazardous things regardless of whether anything is placed on the base member 104 .
[0039] As shown in the embodiment of FIG. 8 , the operative connection between the front member 102 and base member 104 may include a hinge. Any type of hinge known in the art may be utilized, as well as any configuration which provides the same or a similar function. Such a configuration advantageously permits access to the internal environment 108 . The operative connection may allow any desired range of rotation of the front member 102 relative to the base member 104 . In one embodiment, this range of will be such that the front member 102 may be stabilized by a nearby wall 116 or similar partition when in a raised position, thereby increasing the isolation of the internal environment 108 . In one embodiment, the operative connection between the front member 102 and base member 104 is reversible.
[0040] As shown in the embodiment of FIG. 9 , the invention may be disposed such that gaps will exist along the top 120 and/or side 122 permitting the passage of cables 114 and/or other objects, as well as ventilation. Ventilation may also be provided by the disposition of one or more openings 124 in any one or more members. The openings 124 may also advantageously provide attachment points for stabilizing or retaining elements. Furthermore, in one embodiment a top member (not visible in FIG. 9 ) may be configured to include slots and/or holes such that cables 114 and/or other objects may pass therethrough.
[0041] Although not required in various embodiments, as shown in the embodiment of FIG. 10 , the invention may include side members 126 to further isolate an internal environment 108 . One or more edges 128 of the side members 126 may extend rearwardly (relative to the front member 102 ) to any desired extent. In one or more embodiments, it may be advantageous to extend any such edges 128 at least as far as the rearward edge of the base member 104 , thereby providing an increased isolation of the internal environment 108 .
[0042] As shown in the embodiment of FIG. 11 , one or more slots 130 , holes, and/or other openings may be provided in any member of the invention to provide for the passage of cables 114 and other objects, as well as to provide a desired ventilation. Such slots 130 and/or holes may be configured to frictionally retain an object, such as a cable 114 , thereby advantageously providing for an increased organization and separation of such objects and furthermore facilitating the placement and retention of unneeded lengths of cable within the internal environment 108 .
[0043] As shown in the embodiment of FIG. 12 , the invention may be operatively connected to a wall 116 or other partition such that it is supported in an elevated location, and such that it will provide support for any objects placed on a base member 104 thereof, and/or provide a desired degree of isolation of any cables 114 and/or other objects from an external environment 110 . In one embodiment, operative connection of the front member 102 to base member 104 may be reversible or include a hinge to permit access to an internal environment 108 thereof without requiring detachment from the wall 116 or other partition. In one embodiment, such an operative connection will occur by connecting only the base member 104 to the wall 116 or other partition. In one embodiment, the base member 104 may be operatively connected to one or more suspension members 132 , which in turn may be operatively connected to the wall 116 or partition by any means known in the art. Embodiments of the invention may also be operatively connected to any suitable surface of any desired object.
[0044] The various members described herein may comprise any material or combination thereof known in the art. Any desired member may also comprise an insulating material to provide sound and/or thermal insulation to components disposed within the internal environment. Furthermore, such members may be of any size and/or configuration known in the art, and need not conform in terms of size, configuration, style, dimension, composition, or any other variable, with adjacent members. One skilled in the art will understand that a degree of variability is permitted for aesthetic/decorative and/or design purposes, without departing from the spirit of the invention. In one or more embodiments, members or parts thereof may be transparent or partially transparent to allow for the viewing of objects disposed within the internal environment. In one or more embodiments, members may be configured and/or colored to match a wall or partition so as to be less visibly obtrusive. One advantage of embodiments of the invention is the ability to conceal electronic components which might otherwise be visually displeasing. Accordingly, configuration, coloration, and other aspects of embodiments of the invention may be selected to match those of a nearby wall or partition to more effectively conceal both the electronic components, and the embodiment.
[0045] Embodiments of the invention advantageously decrease the risk of injury from electric components and other objects, while also providing a degree of protection for any such objects from the surrounding environment. Although embodiments may be used in a variety of locations, one particularly advantageous location might be under a desk, where cables and various other electric components are often disposed and may be damaged or rendered inoperative by an individual's feet, or possibly harm an individual who makes contact with them. Embodiments will also be advantageous in areas where pets and/or children may contact electric components, thereby injuring themselves.
[0046] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | A device for creating a relatively isolated environment for protecting dangerous and/or fragile components, particularly electrical components, from the surrounding environment. The device will typically include a front member and base member which may be formed as a unitary body. A relatively isolated environment will be formed in the area behind the front member and above the base member and the isolation may be enhanced by placing the device near a wall or partition. The device may also include side members for enhancing the isolation of the internal environment. Openings or slots may be located in any of the members to permit the passage of cables or other tubular objects and also to provide ventilation. Retaining elements disposed on the inside of the base member or front member may be used to retain various components in a desired position. The front member may also include a fan or comfort elements for use as a footrest or cooling device. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 11/475,756 filed Jun. 27, 2006, which claims the benefit of U.S. Provisional Application Ser. No. 60/718,579 filed Sep. 19, 2005.
TECHNICAL FIELD
The present invention relates to a hi-metal disc brake rotor and a method of manufacturing bi-metal brake disc rotors in which an insert is cast into the brake rotor in a manner to provide improved noise damping without subjecting the rotor to corrosion.
BACKGROUND OF THE INVENTION
Motor vehicle disc brake systems utilize a disc brake rotor at each respective wheel, wherein the disc brake rotor typically includes a rotor hat for connecting to an axle hub of a rotatable axle of the motor vehicle, and at least one annular rotor cheek connected to the rotor hat, wherein the at least one rotor cheek has a pair of mutually opposed braking surfaces onto which brake pads are selectively applied when braking is desired. Typically, the rotor cheek configuration may be solid, in which case a single rotor cheek has opposing braking surfaces thereon, or may be vented, in which case a pair of rotor cheeks are mutually separated by a web of ventilation vanes and each rotor cheek provides a respective braking surface so that, in combination, two mutually opposed braking surfaces are provided.
The disc brake system further typically includes a caliper which supports a mutually opposed pair of brake pads, one brake pad disposed overlying a respective rotor cheek braking surface, wherein the caliper, the brake pads, and other associated brake components collectively form a “brake corner”. Normally, the caliper keeps the brake pads separated from the braking surfaces of the one or more rotor cheeks. Braking of the motor vehicle occurs at the brake corner by the caliper pressing the brake pads upon the braking surfaces of the one or more rotor cheeks. Frictional interaction between the one or more rotating rotor cheeks and non-rotating brake pads causes braking of the motor vehicle to transpire, the rate of braking depending upon the pressure of the brake pads against the braking surfaces.
Brake squeal can be undesirably generated at the brake corner when braking occurs. This brake squeal is the result of modal excitations of the disc brake rotor (composed usually of cast iron) by the frictional material of the brake pads. It is known in the prior art that brake squeal can be addressed by reducing modal excitation on the disc brake rotor by the friction material of the brake pads (i.e., lowering the frictional coefficient), by modifying the modal excitation response of the brake corner via changing the modal properties of the rotor cheeks (i.e., in terms of resonant frequencies, mode shapes, and structural damping through higher carbon content of the one or more rotor cheeks and/or increasing the disc brake rotor mass, or using exotic, expensive materials), and by introducing additional damping for example via a shim disposed at a backing plate of the brake pads.
The aforementioned brake squeal countermeasures are relatively effective for most brake corner designs, but they require a significant amount of testing and analytical resources in order to be effective. And unfortunately, brake corners for performance motor vehicles, or those motor vehicles with high friction lining materials, are resistant to the prior art brake squeal countermeasures, due to the high amount of modal excitation from the friction material of the brake pads.
U.S. patent application Ser. No. 10/961,813, filed Oct. 8, 2004, commonly assigned with the present application, and hereby incorporated by reference in its entirety, teaches Coulomb friction damped disc brake rotor configurations having an insert within the rotor to provide improved damping.
SUMMARY OF THE INVENTION
The invention provides a method for manufacturing a friction damped disc brake rotor, including the steps of: (A) providing a ceramic coating or other suitable coating on an insert, wherein the insert has a body with tabs extending therefrom to hold the insert in a desired position within a mold; (B) washing the ceramic coating off of the tabs; (C) positioning the insert into the mold; and (D) casting a rotor cheek of the disc brake rotor in the mold around the insert such that a portion of each tab is bonded with the rotor cheek, and such that the coating is substantially non-bonded with the rotor cheek so that the coating provides a proper interfacial boundary between the body and the cheek for damping, and the at least partial bonding of each tab with the rotor cheek prevents corrosion-causing exterior elements from reaching the interfacial boundary when the friction damped disc brake rotor is in use.
The tabs may be internal to the annular body (i.e. extending from the internal diameter), external to the body (i.e. extending from the outer diameter), or both internal and external to the body. The insert is preferably steel and the casting material is cast iron. The ceramic coating is preferably a mold wash material having alumina and silica particles mixed with an organic binder. Also, the insert is sandblasted prior to application of the coating. The coating is sprayed onto the insert, and the insert is heated at approximately 500 degrees F. for at least approximately 1 hour prior to being positioned in the mold. The coating is locally removed from the tabs after the insert has been heated. The ceramic coating is between approximately 50 and 300 micrometers thick, and the insert is between approximately 1.5 and 2.0 mm thick.
Alternatively, rather than applying the coating to both the body and the tabs and then washing the coating off the tabs, the tabs could be covered (screened) while the coating is applied only to the body. Also, a graphite coating could be applied to the tabs to enhance bonding.
The insert may be provided with stiffening ribs extending radially or annularly. Alternatively, the insert may include a turned down flange along the internal diameter of the annular insert body, and/or may include through holes to facilitate mold filling by preventing lifting of the insert during mold filling.
These and other features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a schematic side sectional view of an insert positioned within a casting mold in accordance with the present invention;
FIG. 1 b shows an enlarged view of area 1 b identified in FIG. 1 a;
FIG. 1 c is a schematic side sectional view of the mold and insert of FIG. 1 a , with the mold closed and molten iron introduced into the mold to form a friction damped disc brake rotor in accordance with the invention;
FIG. 1 d is a schematic side sectional view of the mold of FIG. 1 a , with the mold opened and a friction damped disc brake rotor ejected from the mold in accordance with the invention;
FIG. 2 is a plan view of the insert shown in FIGS. 1 a - d , with alternative configurations shown in phantom;
FIG. 3 is a plan view of an insert in accordance with an alternative embodiment of the invention;
FIG. 3 a is a schematic partial cross-sectional view of an insert having an alternative stiffening bump;
FIG. 3 b is a schematic partial cross-sectional view of an insert having an alternative stiffening downturned flange;
FIG. 4 is a schematic side sectional view of an insert positioned within a mold for casting a friction damped disc brake rotor having a vented rotor cheek, with the mold in the closed position for casting.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a , a mold 10 is accordance with the invention having upper and lower mold halves 12 , 14 which form a cavity 16 therebetween for casting a friction damped disk brake rotor in accordance with the invention. FIG. 1 b shows an insert 18 which is pre-positioned within the mold 10 and having tabs 20 which rest on cutout portions 22 , 24 of the lower mold half 14 . As shown in FIG. 1 c , when the upper and lower mold halves 12 , 14 are closed together, the tabs 20 are supported between the cutout portions 22 , 24 of the lower mold half 14 and the lands 26 , 28 , respectively of the upper mold half 12 .
Referring to FIG. 2 , the insert 18 is shown in plan view. As shown, the insert 18 has a generally annular body 30 with tabs 20 extending therefrom. Each tab includes a distal portion 32 and a proximal portion 34 . The distal portion 32 is trapped between the cutout portions 22 , 24 and the lands 26 , 28 , respectively, shown in FIG. 1 c , while the proximal portion 34 of each tab 20 is exposed to molten metal within the mold cavity 16 .
The mold 10 is preferably a sand mold, and the insert 18 is a pre-manufactured steel component having a coating on opposing surfaces 36 , 38 (shown in FIG. 1 b ) around the entire body 30 . These coated surfaces 36 , 38 do not bond with the cast metal in the casting operation. The lack of “wetting” or affinity along these coated surfaces 36 , 38 produces the desired interfacial boundary for damping. However, the tabs 20 , particularly the proximal portion 34 of each tab 20 , is configured in a manner to bond with the cast metal of the rotor cheek. Since the coated surfaces 36 , 38 of the insert 18 do not bond with the cast metal of the rotor cheek, a proper interfacial boundary is formed with the cheek for damping. However, the bonding of the tabs, particularly the proximal portions 34 thereof, with the cast metal of the rotor cheek prevents corrosion causing exterior elements from reaching the interfacial boundary between the coated surfaces 36 , 38 and the cast metal rotor cheek. This bonding may be achieved by first coating the tabs 20 with the same material which forms the coated surfaces 36 , 38 of the body 30 and then cleaning the coating off the tabs 20 to locally remove the coating to allow the tabs to be micro-welded to the cast iron to effectively seal the rest of the insert/iron interface from intrusion by water or other elements from the exterior of the casting. Alternatively, rather than applying a coating across the entire insert and then locally cleaning the tabs, a graphite coating may be applied to the tabs 20 to enhance bonding with the cast metal. So called “wetting” of the tab edges can also be accomplished by masking the tab prior to application of the coating. The insert may comprise any material having a melting point higher than that of cast iron that would not be dissolved during the casting process.
The above-referenced coated surfaces 36 , 38 must first be cleaned free of oil, rust or dirt. Degreasers may be used to remove thin films of oil, and steel wool may be used to remove rust. The best results are attained when the steel insert is sand blasted, which removes both oil and rust. It also roughens up the surface which helps the coating adhere better.
The preferred coating material is a ceramic mold wash material sold under the trade name IronKote, and is available from Vesuvius Canada Refractories, Inc. of Welland, Ontario. IronKote has alumina and silica particles mixed with an organic binder. It is approximately 47.5% alumina and 39.8% silica with a lignisole (lignosulfanate) binder. The coating preferably has a thickness between approximately 50 and 300 micrometers. Other ceramic coatings having a melting point higher than cast iron may be used.
Once the insert is cleaned and free of oil and rust, it is dipped in or sprayed with IronKote on both sides 36 , 38 and allowed to air dry. The insert is then placed in an oven at 500 degrees F. for 45 minutes. This minimizes absorbed water and organic binders, and provides a relatively uniform coating.
Once this coating process is completed, steel wool is used to locally remove the coating from the tabs. With the coating removed from the tabs, bonding occurs between the cast iron and the steel tabs of the insert.
Referring to FIG. 1 d , mold 10 is shown in the open position with the final friction damped disk brake rotor 40 removed from the mold cavity. As shown, the friction damped disk brake rotor 40 has a hat portion 42 with a rotor cheek 44 extending about the periphery thereof, and the insert 18 positioned within the cheek 44 . The distal end 32 of the tabs 20 of the insert 18 would be machined off after the friction damped disk brake rotor 40 is removed from the mold 10 .
The locating tabs can be used on the ID, OD or both positions to stabilize the insert during the metal casting operation. For example, the insert 18 of FIG. 2 has optional internal tabs 56 shown in phantom. The number and placement of tabs depends on the specific rotor geometry and its dimensions, and on the thickness of the steel insert. The tabs 56 and 20 may be used together, or separately.
The steel inserts are preferably 1.5 to 2 mm in thickness, but other thicknesses may be used. The thicknesses are chosen to prevent bending of the insert while not being so thick as to “chill” the surrounding casting to the point that objectionable carbides are produced.
By preventing the steel insert from reacting with the iron during casting, the interfaces are maintained for desired sound damping. By enhancing the bond between the tabs and the cast steel, the gap at the tab areas is eliminated in order to isolate the interfaces from the casting exterior environment to eliminate corrosion issues in service. Also, more than one insert may be cast in place in the rotor.
FIG. 2 also shows in phantom optional through holes 45 , which facilitate mold filling while minimizing action of molten metal to move the insert 18 . In other words, the holes 45 prevent molten material from lifting up the insert, as the mold is filled from below through the gate channel 47 shown in FIG. 1 d . By gating below the part and using a horizontal pouring process, metal is not directed onto or splashed onto the insert prematurely. Also, quiescent mold filling prevents splashing of metal droplets on to the insert prior to general contact with molten metal during mold filling to avoid premature solidification of small droplets of iron.
Also, the molten material is preferably filtered at the gate channel 47 , shown in FIG. 1 d , with a ceramic filter to reduce slag related defects.
Turning to FIG. 3 , an alternative insert 18 A is shown, including annular stiffening rib 41 and radial stiffening ribs 43 , which are coextensive with the tabs 20 . These optional ribs 41 , 43 help maintain the position and shape of the insert 18 A during mold filling (i.e. prevents “potato-chipping”). The ribs are preferably 0.040 inch thick with a 0.060 inch (1.5 mm) thick insert.
Alternatively, the stiffening rib 41 may be a stiffening ridge 41 A as shown in the schematic partial cross-sectional view of insert 18 B in FIG. 3 a . Referring to FIG. 3 b , in a further alternative embodiment, the inside diameter 49 of the annular body of the insert 18 A, shown in FIG. 3 , may include a turned down flange 41 B as shown schematically in the partial cross-sectional view of the insert 18 C of FIG. 3 b . These various stiffening ribs help maintain the position and shape of the insert 18 , 18 A, 18 B or 18 C during mold filling.
FIG. 3 also illustrates relief areas 71 , shown in phantom to represent clearance provided in the mold cavity formed in the area of cutout portions and lands 22 , 26 , 24 and 28 in FIG. 1 c . These relief areas 71 in the mold 10 allow the insert to expand without deformation as the molten metal heats it.
The present invention provides reduced disk brake noise and squeal, and limits corrosion of an exposed insert after machining.
It is to be understood that the procedure outlined above can also be used with vented rotor cheek configurations, with a note that an insert or inserts are provided at both or selective one of the rotor cheeks. For example, FIG. 4 shows a mold 60 having upper and lower mold halves 62 , 64 forming a mold cavity 66 therebetween for forming a friction damping disc brake rotor with a vented cheek configuration. A pre-manufactured core with a web pattern 68 and insert 70 are supported within the mold cavity 66 and cast over. The core with web pattern 68 forms the venting configuration of the cheek. The insert 70 has tabs 72 supported between cutouts 74 and lands 76 . As in the embodiment described with reference to FIG. 1 a - d , the tabs 72 are configured to bond to the cast metal, while the body of the insert is coated and does not bond to the cast metal in order to form a proper interfacial boundary for damping. The bonding of the tabs prevents corrosion.
To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims. | The invention provides a method for manufacturing a friction damped disc brake rotor, including the steps of: (A) providing a ceramic coating on an insert, wherein the insert has a body with tabs extending therefrom to hold the insert in a desired position within a mold; (B) washing the ceramic coating off of the tabs; (C) positioning the insert into the mold; and (D) casting a rotor cheek of the disc brake rotor in the mold around the insert such that a portion of each tab is bonded with the rotor cheek, and such that the coating is substantially non-bonded with the rotor cheek so that the coating provides a proper interfacial boundary between the body and the cheek for damping, and the at least partial bonding of each tab with the rotor cheek prevents corrosion-causing exterior elements from reaching the interfacial boundary when the friction damped disc brake rotor is in use. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the invention described herein pertain to the field of cable rail systems. More particularly, the embodiments described herein enable the movement of objects such as a camera using cable or rope through multiple environments such as liquid and gas.
[0003] 2. Description of the Related Art
[0004] There are no known systems that can move objects along a path through multiple environments such as liquid and gas. Known systems are capable of moving an object through air or through water, but not both. Systems that can move objects through air allow support an object from above using cable for example. Systems that move objects through the water using cables either suspend an object from the surface of the water (i.e., from above) or suspend a buoyant object by restraining the object from below. There are no known systems that are capable of stable movement a suspended object when the object leaves one environment and enters another. For example, if an object is moved at a given rate of speed horizontally through the air and the object enters the water, then the speed of the object is reduced and the movement of the object is limited based on the buoyancy of the particular object. Many other problems exist when attempting to provide stable speeds regardless of the environment. This limits the usefulness of cameras tracking certain objects through the air and water for example. For at least the limitations described above there is a need for system that can move objects through multiple environments.
BRIEF SUMMARY OF THE INVENTION
[0005] One or more embodiments of the invention enable the movement of an object through multiple environments such as liquid and gas for example using rope or cable. Various objects can be moved using one or more embodiments of the invention such as a human or camera for example. Displacing a camera vertically between environments while moving the camera horizontally allows for highly stable motion pictures to be taken using one or more embodiments of the invention.
[0006] To enable this type of movement, embodiments of the invention are configured to move an object by relocating one or more lines that are coupled to a plurality of sides of the object. The lines can be any type of flexible connective material such as rope, cable, string, cord, wire or any other similar material.
[0007] The exact reeving or arrangement of the lines is dependent upon the embodiment of the invention. In each embodiment at least two opposing sides of an object are coupled in the vertical axis to allow for upward and downward forces to constraint the vertical displacement of the object. This also provides stability for the dynamic entry and exit from one environment to another. Bull wheels are generally used to displace line from one side of the system to the other. This may include horizontal axis displacement (X-axis) and vertical displacement (Z-axis). In other embodiments utilizing three-dimensional positioning capabilities, a Y-axis displacement is also enabled.
[0008] For example, although the embodiments shown in the attached figures describe a reeving that allows for independent movement of X and Z axes, other reevings can also provide such capabilities that any combination of the reevings enabled in the following applications may be utilized in the upper or lower portion of the system to achieve two or three dimensional movement capabilities. For example, a reeving found in U.S. patent application Ser. No. 10/368,137 may be used to couple with the top portion of a platform while the lower portion of the platform may utilize embodiments described in the detailed description below. Alternatively, the lower portion of a platform may be coupled with the reeving found in any of the following applications while the upper portion may utilize the reevings described herein. U.S. patent application Ser. No. 10/368,137 now U.S. Pat. No. 6,886,471 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/604,525 now U.S. Pat. No. 6,809,495 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/604,667, filed Aug. 8, 2003 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/605,778, filed Oct. 25, 2003 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/708,158, filed Feb. 12, 2004 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/709,918, filed Jun. 4, 2004 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/709,994, filed Jun. 8, 2004 is hereby incorporated herein by reference. U.S. patent application Ser. No. 10/906,621, filed Feb. 27, 2005 is hereby incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a side view of the reeving of a two-dimensional embodiment of the invention utilizing a hydrodynamic truss configured to travel horizontally across the written page with an object traveling vertically up and down the written page.
[0010] FIG. 2 illustrates a side view of the reeving of a two-dimensional embodiment of the invention that moves a hydrodynamic object without the use of a hydrodynamic truss.
[0011] FIG. 3 illustrates an isometric view of the truss and dolly employing externally reeved lines.
[0012] FIG. 4 illustrates an isometric view of the truss and dolly employing internally reeved lines.
[0013] FIG. 5 illustrates an isometric view of the hydrodynamic object shown in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0014] A multi-environment object movement system and method will now be described. In the following exemplary description numerous specific details are set forth in order to provide a more thorough understanding of embodiments of the invention. It will be apparent, however, to an artisan of ordinary skill that the present invention may be practiced without incorporating all aspects of the specific details described herein. In other instances, specific features, quantities, or measurements well known to those of ordinary skill in the art have not been described in detail so as not to obscure the invention. Readers should note that although examples of the invention are set forth herein, the claims, and the full scope of any equivalents, are what define the metes and bounds of the invention.
[0015] FIG. 1 shows an embodiment of the invention having two environments G and L, wherein G stands for gaseous and L stands for liquid environments respectively. Platform 151 in the center of the figure is the object or is coupled to the object to be moved using this embodiment of the invention.
[0016] Platform 151 may move vertically up and down the written page when Z movement line 102 is moved from one side of platform 151 to the other. For instance when Z movement motor 130 rotates counterclockwise line 102 flows down from sheave 140 from sheave 173 and from sheave 190 (coupled with the upper side of platform 151 ). While line 102 is moving in this direction, line 102 is also moving into sheave 141 into sheave 183 and into sheave 191 (coupled with the lower side of platform 151 ). In this manner, platform 151 ascends vertically. By rotating Z movement motor 130 in the clockwise direction, platform 151 descends vertically. By rotating Z movement motor 130 , the X axis displacement of platform 151 does not change. This means that the Z axis movement is independent of the X axis movement. Moving the platform vertically allows for multiple environments such as liquid and gaseous environments to be traversed.
[0017] Platform 151 may move horizontally (left and right) along the written page when X movement lines 103 and 104 are moved from one side of platform 151 to the other. For instance when X movement motor 110 rotates counterclockwise line 103 flows down from sheave 120 from sheave 124 which pulls skate 170 (coupled with the right side of platform 151 ) to the right. The bull wheel driving X movement line 103 moves line 103 up into sheave 121 which allows skate 170 to travel to the right. While the X movement motor is rotating in the counterclockwise direction, line 104 , coupled with a second bull wheel driven by X movement motor 110 moves line 104 from sheave 122 from sheave 125 which pulls skate 180 (coupled with the right side of platform 151 via the Z movement line 102 ) to the right. While line 104 exits the bull wheel coupled to X movement motor 110 it enters sheave 123 which allows skate 180 to travel to the right. In this manner, platform 151 is pulled to the right in the figure. By rotating X movement motor 110 in the clockwise direction, platform 151 moves to the left in the figure. By rotating X movement motor 110 , sheaves 173 , 190 , 174 and 183 , 191 , 184 to travel freely allowing the Z axis displacement of platform 151 to remain constant. This means that the X axis movement is independent of the Z axis movement.
[0018] During X axis movement, tracks 100 and 101 allow for rollers or sheaves 171 , 172 , 181 and 182 to roll or travel along tracks 100 and 101 . The tracks may be rigid or highlines under tension depending upon the particular requirements of the implementation.
[0019] Z movement line 102 may be doubled-up so that both sides of the platform, namely the side nearest the reader and the side beneath the written page are acted upon. In addition, embodiments of the truss 150 allow for at least one groove to allow for internal reeving of line 102 so that the line is housing within truss 150 . Truss 150 may be hydrodynamically shaped allowing for ease of X axis traversal while platform 151 may also be hydrodynamically shaped.
[0020] FIG. 2 shows another embodiment of the invention that does not use a truss. In this embodiment of the invention, platform 200 is coupled with sheaves 190 and 191 and moves vertically and horizontally in the same manner as described with respect to FIG. 1 . In other words, X axis and Z axis movement is accomplished by moving X axis and Z axis motors in the same direction to affect the same direction of movement in this embodiment as well. Although high speed X axis movement may yield cavitation effects, since sheaves 190 and 191 provide a Z axis displacement above and below platform 151 , a camera for example would not view the low pressure bubbles unless panned into a vertical orientation.
[0021] Skate 180 may comprise a hydrodynamically shaped enclosure in one or more embodiments of the invention. Sheaves 190 and 191 may comprise generating elements that allow for power to be derived within platform 200 (or 151 in FIG. 1 ). A video camera housed in any platform embodiment may comprise a pre-programmed shot sequence or may comprise an input that allows for complete control of all camera operations and may comprise the video signal from the camera output as well.
[0022] FIG. 3 shows an embodiment of the truss and platform of FIG. 1 . Truss 150 in this embodiment is hydrodynamically shaped so that movement through a liquid environment requires less power, achieves greater speeds for a given X movement motor and allows for smaller X movement motors to be deployed for a desired application requiring a specified speed. In this embodiment, forward and rear pointing enclosures 160 are shown on opposing sides of the platform. Z movement line 102 is shown descending vertically to sheave 190 and ascending vertically to sheave 191 from below. As the sheaves are mounted on the outside of platform 151 in this example any mechanism for providing low friction traversal of platform 151 up and down truss 150 is in keeping with the spirit of the invention. For instance, rollers or bearings between the inside of platform 151 and the outside of truss 150 may be used in various embodiments of the invention to provide smoother vertical travel depending upon the application requirements. Forward and rear pointing enclosures 160 may be utilized in housing sensors such as a camera for example.
[0023] FIG. 4 shows an embodiment of the invention comprising a groove in truss 150 on the nearest face of truss 150 . This allows for sheaves 190 and 191 to be internally mounted which therein allows Z movement line 102 to travel unimpeded through space without interacting with the environment(s) that that platform is currently in. Many different variations of the internal mounting are in keeping with the spirit of the invention. For example, Z movement line 102 may be doubled-up by allowing for two grooves, one on each opposing face of truss 150 that would allow for a more even pull-up or pull-down of platform 151 . In this configuration, a connector between the furthest points in the truss substantially parallel to the faces of the truss would allow for two grooves. Although platform 151 is shown with a flat top and bottom, any other shape that provides for smooth flow through a liquid and gas may be utilized. For example, an elliptical platform 151 with a vertical slot matching the contour of truss 150 is in keeping with the spirit of the invention. Any other shape may be used with more hydrodynamically shaped embodiments of the platform allowing for higher speed or smaller motor implementations.
[0024] FIG. 5 shows an embodiment of the invention not using a truss. Platform 200 in this embodiment is an ellipsoid such as an oblate spheroid, sphere or elongated ellipsoid aligned with the planes formed by sheaves 190 and 191 . In this embodiment there is no truss to provide hydrodynamic shielding of the upper or lower side of Z movement line 102 . Sheaves 190 and 191 provide fins to stabilize platform 200 in this embodiment. Camera 500 is shown panned in the direction of travel to the right and slightly upward in the figure. Platform 200 in this embodiment is shown as a transparent enclosure. Electronic processing of images taken in any shape of platform 200 allows for aberration correction of the images and may account for the refraction indices of the enclosure, the liquid environment and the optical properties of the camera lenses themselves.
[0025] FIG. 6 shows an embodiment of the invention utilizing the reeving of U.S. patent application Ser. No. 10/368,137 now U.S. Pat. No. 6,886,471 in the upper environment area. The upper reeving 600 is described in the '471 patent which is hereby incorporated herein by reference. The lower reeving 601 is the lower reeving of FIG. 1 . Moving the X movement line with X movement motor 110 and utilizing the X movement motor of the '471 patent in an equal amount yields X movement that is independent of Y axis and Z axis position of platform 200 . In this embodiment Y axis movement is also possible (left to right on the written page). When moving in the Y axis, Z movement line from the lower reeving may inserted towards platform 200 to keep platform 200 at a given height as the platform traverses in the Y axis.
[0026] FIG. 7 shows an embodiment of the invention utilizing the reeving of U.S. patent application Ser. No. 10/604,667, filed Aug. 8, 2003 which is hereby incorporated herein by reference. The upper reeving 700 is described in the '667 application. The lower reeving is the lower reeving of FIG. 1 . Moving the X movement line with the X movement motor 110 and utilizing the X movement motor of the '667 application in an equal amount yields X movement that is independent of the Y axis and Z axis position of platform 200 . In this embodiment Y axis movement is also possible (left to right on the written page although the axis names are arbitrary in the horizontal plane). When moving in the Y axis, Z movement line from the lower reeving may inserted towards platform 200 to keep platform 200 at a given height as the platform traverses in the Y axis.
[0027] FIG. 8 shows an embodiment of the invention utilizing the reeving of U.S. patent application Ser. No. 10/709,994, filed Jun. 8, 2004 which is hereby incorporated herein by reference. The upper reeving 800 is described in the '994 application. The lower reeving is the lower reeving of FIG. 1 . Moving the X movement line with the X movement motor 110 and utilizing the X movement motor of the '994 application in an equal amount yields X movement that is independent of the Y axis position of platform 200 . In this embodiment Y axis movement is also possible (left to right on the written page although the axis names are arbitrary in the horizontal plane). When moving in the Y axis, Z movement line from the lower reeving may inserted towards platform 200 to keep platform 200 at a given height as the platform traverses in the Y axis. In addition, as the path of platform 200 is ellipsoidal using the top reeving 800 , Z movement line using the lower reeving may be injected or retracted to or from platform 200 to account for the ellipsoidal path of upper reeving 800 when moving platform 200 . Likewise the upper reeving can account for the ellipsoidal path by utilizing the Z movement motor described in the '994 patent application.
[0028] FIG. 9 shows the reeving in U.S. patent application Ser. No. 10/906,621, filed Feb. 27, 2005 as lower reeving 900 . Upper reeving 901 is shown in the upper portion of FIG. 1 of this application. This embodiment shows that truss 150 may also be used in any of the embodiments including this one. The '621 patent application is hereby incorporated herein by reference.
[0029] Although there is no requirement to align upper and lower reevings along an axis as shown in FIGS. 6, 7 , 8 or 9 , doing so allows for independent axial movement as described above. For situations where the axes are skewed between the upper and lower reevings, Z movement line may be introduced or removed to and from platform 200 in order to keep the platform moving in a straight path, or at a given X, Y or Z position. Although platform 200 has been shown in FIGS. 6, 7 , 8 for ease of illustration, a truss may be inserted between upper and lower reevings in any of the embodiments shown in order to created a hydrodynamic traversal guide for a platform as demonstrated in FIG. 9 .
[0030] Although each of the lower reevings shown in FIGS. 6, 7 and 8 are of the embodiments described herein, the entire system may be flipped upside down in each of these figures in order to position the reeving described herein in the top location as has been demonstrated in FIG. 9 . Alternatively, any of the reevings described in FIGS. 6, 7 and 8 and the reeving herein may be mixed and matched as needed for the application so long as tension is maintained on opposing sides of platform 200 in order to stabilize platform 200 when for example moving between environments. Independence of X and Z axes may be automatic and not require computer control of the upper or lower reeving, or may utilize computer control of one or both reevings in order to provide independence of the axes depending on the reevings utilized in both the upper and lower portions of the implementation.
[0031] While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. | One or more embodiments of the invention enable the movement of an object through multiple environments such as liquid and gas for example using rope or cable. Various objects can be moved using one or more embodiments of the invention such as a human or camera for example. Displacing a camera vertically between environments while moving the camera horizontally allows for highly stable motion pictures to be taken using one or more embodiments of the invention. To enable this type of movement, embodiments of the invention are configured to move an object by relocating one or more lines that are coupled to a plurality of sides of the object. The lines can be any type of flexible connective material such as rope, cable, string, cord, wire or any other similar material. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a video camera system whose lens assemblies are interchangeable.
Conventionally, a so-called hill-climbing method is known as the method of an automatic focusing (AF) device used in video apparatuses such as video cameras. The method performs focusing by extracting a high-frequency component from a video signal obtained by an image sensing device such as a CCD and driving a taking lens such that the mountain-like characteristic curve of this high-frequency component is a maximum.
This automatic focusing method requires no special focusing optical members and has an advantage in that an object can be accurately focused regardless of whether the distance to the object is long or short. An example in which an automatic focusing method of the above sort is applied to an interchangeable lens video camera will be described below with reference to FIG. 24 .
Referring to FIG. 24, in a lens assembly 816 , a variable power lens 802 and a compensating lens 803 are connected by a mechanical cam (not shown). When a zooming operation is manually or electrically performed, the variable power lens 802 and the compensating lens 803 integrally move.
These variable power lens 802 and compensating lens 803 are called zoom lenses.
In this lens system, a front lens 801 which is closest to an object when the image is taken is a focus lens. The focus lens 801 moves in the direction of an optical axis to perform focusing.
An image of light transmitting through these lenses is formed on the image sensing surface of an image sensing device 804 of a camera 817 , photoelectrically converted into an electrical signal, and output as a video signal.
This video signal is sampled-and-held by a CDS/AGC circuit 805 constituted by a correlated double sampling circuit and an auto gain control circuit, amplified to a predetermined level, and converted into digital video data by an analog/digital (A/D) converter 806 . The digital video data is input to the process circuit (not shown) of the camera 817 and converted into a standard TV signal. The data is also input to a bandpass filter (to be referred to as a BPF hereinafter) 807 .
The BPF 807 extracts a high-frequency component which changes in accordance with the focus state from the video signal. A gate circuit 808 extracts only a video signal corresponding to a portion which is set as a focus detection area in a picture frame. A peak hold circuit 809 holds a peak of the video signal at an interval synchronizing with an integral multiple of a vertical sync signal, thereby generating a focus state evaluation value (to be referred to as an AF evaluation value hereinafter) representing the in-focus degree in the automatic focusing operation.
The AF evaluation value is fetched by an AF control microcomputer (to be referred to as a main body AF microcomputer hereinafter) 810 on the camera main body 817 side. The main body AF microcomputer 810 determines the focusing speed, i.e., a focus motor speed in accordance with the in-focus degree and the driving direction of the focus motor along which the AF evaluation value increases. The main body AF microcomputer 810 sends the speed and direction of the focus motor to a lens control microcomputer of the lens assembly 816 .
A lens microcomputer 811 controls a focus motor 813 through a motor driver 812 in accordance with an instruction from the main body AF microcomputer 810 to drive the focus lens 801 along the optical axis, thereby performing the focusing operation.
The main body AF microcomputer 810 also determines the driving directions and the driving speeds of the variable power lens 802 and the compensating lens 803 , which constitute zoom lenses, in accordance with the operation state of a zoom switch 818 . The main body AF microcomputer 810 transmits these driving directions and driving speeds to a zoom motor driver 814 of the lens assembly 816 . The lens assembly side calculates the driving information of a zoom motor 815 in accordance with the zoom speed and direction information sent from the camera main body side and drives the zoom motor 815 through the motor driver 814 , thereby driving the variable power lens 802 and the compensating lens 803 .
The camera main body 817 can be detached from the lens assembly 816 and connected to another lens assembly. This widens the sensing range.
In recent popular cameras integrated with video recorders for consumers having the above structure, the front lens is fixed while the focus lens is arranged behind the variable power lens, and the cam for mechanically connecting the compensating lens to the variable power lens is no longer used in order to miniaturize a camera and enable sensing at a close distance such as when an object is just in front of the lens. In these cameras, the locus of movement of the compensating lens is previously stored as lens cam data in a microcomputer, and the compensating lens is driven in accordance with this lens cam data. Also, a focusing operation is performed by using this compensating lens. Lenses of this type, i.e., so-called inner focus type (rear focus type) lenses have become most popular.
A zooming operation by such an inner focus type lens will be described below.
FIG. 25 is a view schematically showing the arrangement of a general inner focus type lens system.
Referring to FIG. 25, reference numeral 901 denotes a fixed first lens group; 902 , a second lens group for performing a zooming operation; 903 , an iris stop; 904 , a fixed third lens group; 905 , a fourth lens group (to be referred to as a focus lens hereinafter) having both a focusing function and a so-called compensator function of compensating for the movement of a focal plane caused by zooming; and 906 , an image sensing device.
As is well known, in the lens system as illustrated in FIG. 25, the focus lens 905 has both the compensating function and the focusing function. Accordingly, the position of the focus lens 905 for focusing an image on the image sensing surface of the image sensing device 906 changes in accordance with the object distance even at the same focal length.
FIG. 26 shows the result of continuous plotting of the position of the focus lens 905 for focusing an image on the image sensing surface while the distance between the focus lens 905 and the object is changed at different focal lengths.
During the zooming operation, one of the loci shown in FIG. 26 is selected in accordance with the object distance, and the focus lens 905 is moved to trace that focus. This allows a zooming operation free from a blur.
In a conventional front lens focus type lens system, compensating lens is provided independently of a variable power lens, and the variable power lens and the compensating lens are coupled by a mechanical cam ring. A manual zoom knob, for example, is formed on this cam, and the focal length is manually changed. Even if the knob is moved as fast as possible, the cam rotates to trace the movement of the knob, and the variable power lens and the compensating lens move along a cam groove for holding the cam. Therefore, no blur is caused by the above operation as long as the focus lens is focused on an object.
In controlling the inner focus type lens system, however, a plurality of pieces of locus information shown in FIG. 26 are stored in some format (the locus itself or a function of a lens position as a variable). In general, one of the loci is selected in accordance with the positions of the focus lens and the variable power lens, and a zooming operation is performed while tracing the selected locus.
FIG. 28 is a graph for explaining one invented locus tracing method. In FIG. 28, reference symbols Z 0 , Z 1 , Z 2 , . . . , Z 6 denote the positions of the variable power lens; and a 0 , a 1 , a 2 , . . . , a 6 and b 0 , b 1 , b 2 , . . . , b 6 , representative loci stored in the microcomputer.
Also, p 0 , p 1 , p 2 , . . . , p 6 denote loci calculated on the basis of the above two loci. This locus calculation is done by the following equation:
p ( n +1)=| p ( n )− a ( n )|/| b ( n )− a ( n ) |*| b ( n +1)− a ( n +1)|+ a ( n +1) (1)
In equation (1), if, for example, the focus lens is at p 0 in FIG. 28, the ratio at which p 0 internally divides a line segment b 0 -a 0 is calculated, and the point at which a line segment b 1 -a 1 is internally divided by this ratio is given as p 1 . The focus lens moving speed for holding the in-focus state can be known from this positional difference (p 1 −p 0 ) and the time required for the variable power lens to move from Z 0 to Z 1 .
An operation when there is no such limitation that the stop position of the variable power lens must be on a boundary having the previously stored representative locus data will be described below.
FIG. 29 is a graph for explaining an interpolation method along the direction of the variable power lens position. FIG. 29 extracts a part of FIG. 28, and the position of the variable power lens is not limited to the previously stored positions, so that the variable power lens can take any arbitrary position.
In FIG. 29, the ordinate indicates the focus lens position, and the abscissa indicates the variable power lens position. The representative locus positions (the focus lens positions with respect to the variable power lens positions) stored in the microcomputer are represented as follows for various object distances with respect to variable power lens positions Z 0 , Z 1 , . . . , Zk−1, Zk, . . . , Zn:
a 0 , a 1 , . . . , ak−1, ak, . . . , an
b 0 , b 1 , . . . , bk−1, bk, . . . , bn
If the variable power lens position is Zx not on a zoom boundary and the focus lens position is Px, ax and bx are calculated as follows:
ax=ak −( Zk−Zx )*( ak−ak −1)/( Zk−Zk −1) (2)
bx=bk −( Zk−Zx )*( bk−bk −1)/( Zk−Zk −1) (3)
That is, ax and bx can be calculated by internally dividing data having the same object distance of the four stored representative locus data (ak, ak−1, bk, and bk−1 in FIG. 29) by the internal ratio obtained from the current variable power lens position and the two zoom boundary positions (e.g., Zk and Zk−1 in FIG. 29) on the two sides of the current variable power lens position.
In this case, pk and pk−1 can be calculated, as shown in equation (1), by internally dividing data having the same focal length of the four stored representative data (ak, ak−1, bk, and bk−1 in FIG. 29) by the internal ratio obtained from ax, px, and bx.
When zooming is performed from wide to telephoto, the focus lens moving speed for holding the in-focus state can be known from the positional difference between the focus position pk to be traced and the current focus position px and the time required for the variable power lens to move from Zx to Zk.
When zooming is performed from telephoto to wide, the focus lens moving speed for holding the in-focus state can be known from the positional difference between the focus position pk−1 to be traced and the current focus position px and the time required for the variable power lens to move from Zx to Zk−1. The locus tracing method as described above is invented.
When AF control is performed, it is necessary to trace the locus while maintaining the in-focus state. When the variable power lens moves in a direction from telephoto to wide, the diverged loci converge as can be seen from FIG. 26 . Therefore, the in-focus state can be maintained by the above locus tracing method.
In a direction from wide to telephoto, however, a locus which the focus lens in the point of convergence is to trace is unknown. Consequently, the in-focus state cannot be maintained by the locus tracing method as above.
FIGS. 30A and 30B are graphs for explaining one locus tracing method invented to solve the above problem. In each of FIGS. 30A and 30B, the abscissa indicates the position of a variable power lens. In FIG. 30A, the ordinate indicates the level of a high-frequency component (sharpness signal) of a video signal as an AF evaluation signal. In FIG. 30B, the ordinate indicates the position of a focus lens.
Assume that in FIG. 30B, a focusing cam locus is a locus 604 when a zooming operation is performed for a certain object.
Assume also that a tracing speed with respect to a locus indicated by lens cam data closer to a wide side than a zoom position 606 (Z 14 ) is positive (the focus lens is moved to the closest focusing distance), and that a tracing speed with respect to a locus indicated by lens cam data when the focus lens is moved in the direction of infinity on a telephoto side from the position 606 is negative.
When the focus lens traces the locus 604 while being kept in the in-focus state, the magnitude of the sharpness signal is as indicated by 601 in FIG. 30 A. It is generally known that a zoom lens kept in the in-focus state has an almost fixed sharpness signal level.
Assume that in FIG. 30B, a focus lens moving speed for tracing the focusing locus 604 during a zooming operation is Vf 0 . When an actual focus lens moving speed is Vf and a zooming operation is performed by increasing or decreasing Vf with respect to Vf 0 for tracing the locus 604 , the resulting locus is zigzagged as indicated by reference numeral 605 .
Consequently, the sharpness signal level so changes as to form peaks and valleys as indicated by reference numeral 603 . The magnitude of the level 603 is a maximum at positions where the loci 604 and 605 intersect (at even-numbered points of Z 0 , Z 1 , . . . , Z 16 ) and is a minimum at odd-numbered points where the moving direction vectors of the locus 605 are switched.
Reference numeral 602 denotes a minimum value of the level 603 . When a level TH 1 of the value 602 is set and the moving direction vectors of the locus 605 are switched every time the magnitude of the level 603 equals the level TH 1 , the focus lens moving direction after switching can be set in a direction in which the movement approaches the in-focus locus 604 .
That is, each time an image is blurred by the difference between the sharpness signal levels 601 and 602 (TH 1 ), the moving direction and speed of the focus lens are so controlled as to decrease the blur. Consequently, a zooming operation by which a degree (amount) of blur is suppressed can be performed.
The use of the above method is effective even in a zooming operation from wide to telephoto, as shown in FIG. 26, in which converged loci diverge. That is, even if the in-focus speed Vf 0 is unknown, the switching operation is repeated as indicated by 605 (in accordance with a change in the sharpness signal level) while the focus lens moving speed Vf is controlled with respect to the tracing speed (calculated by using p(n+1) obtained from equation (1)) explained in FIG. 28 . As a consequence, it is possible to select an in-focus cam locus by which the sharpness signal level is not decreased below the level 602 (TH 1 ), i.e., a predetermined amount or more of blur is not produced.
Assuming a positive compensating speed is Vf+ and a negative compensating speed is Vf−, the focus lens moving speed Vf is determined by
Vf=Vf 0 + Vf + (4)
Vf 0 + vf − (5)
In order that no deviation is produced when the tracing locus is selected by the above method of zooming operation, the compensating speeds Vf+ and Vf− are so determined that the internal angle of the two vectors of Vf obtained by equations (4) and (5) is divided into two equal parts by the direction vector of Vf 0 .
FIG. 31 is a table showing table data of locus information stored in the microcomputer. FIG. 31 shows in-focus lens position data A (n,v) which changes depending on the zoom lens position at different object distances. The object distance changes in the column direction of a variable n, and the zoom lens position (focal length) changes in the row direction of a variable v.
In this case, n=0 represents an object distance in the direction of infinity. As the variable n becomes large, the object distance changes to the closest focusing distance, and n=m represents an object distance of 1 cm.
On the other hand, v=0 represents a zoom lens position at the wide end. As the variable v becomes large, the focal length increases. Additionally, v=s represents a zoom lens position at the telephoto end.
Therefore, table data of one column corresponds to one cam locus. Locus information shown in FIG. 31 is prepared as zoom tracking data on the basis of an optical design value. With an actual lens, a locus corresponding to the design value cannot be obtained because of, e.g., an error in focal length of each lens group.
More specifically, to execute the locus tracing operation free from a blur as described above, the coordinate axes of an actual lens must match those of the table data.
An actual video camera performs an adjustment operation to determine the telephoto and wide ends of the variable power lens in data stored in advance.
A focusing adjustment method is conventionally performed, in which the operation stroke of a variable power lens from the telephoto end to the wide end is kept to be the design value. The in-focus position difference (balance) between the focus lens at the telephoto end and that at the wide end within an adjustment distance (e.g., ∞) is also set to be the design value, thereby defining the telephoto and wide ends. This adjustment method will be referred to as “fixed stroke adjustment”.
Another focusing adjustment method is known, in which the difference (balance) between the in-focus position of a focus lens at the telephoto end and that at the wide end is set to be a design value. In addition, a variable power lens position is obtained, at which the uppermost position of the focus lens at the middle (intermediate focal length) on the map as shown in FIGS. 26 and 27 and the moving amount of the focus lens from the telephoto end equal the design values, and defining the telephoto and wide ends of the variable power lens. This method will be referred to as “telephoto-middle tracking adjustment”. “Fixed stroke adjustment” and “telephoto-middle tracking adjustment” performed using a lens group having an error in a direction of increasing the position of the focus lens when the telephoto end position and the wide end position are set at not the design values but the intermediate focal length will be described below with reference to FIG. 27 .
In FIG. 27, the abscissa indicates the position of a variable power lens (i.e., a focal length), and the ordinate indicates the position of a focus lens. A locus Sb corresponds to a design locus. An actual focus lens exhibits a locus Sa. At this distance (e.g., ∞), the difference between the in-focus position of the focus lens at a telephoto end T and that at a wide end W is zero.
If the locus corresponds to the design value, and telephoto-middle tracking adjustment is to be performed, a point {circle around (1)} on the map is a start point for adjustment. The focus lens is lowered downward in FIG. 27 by a design moving amount A of the focus lens. This position is indicated by {circle around (2)}. From this state, the variable power lens is moved to obtain an in-focus position {circle around (5)} which is defined as a variable power lens position Tb at the telephoto end.
In this example, the difference between the in-focus position of the focus lens at the wide end and that at the telephoto end is zero, as described above. Therefore, the variable power lens is moved in a similar manner, and an in-focus position {circle around (6)} is defined as a variable power lens position Wb at the wide end.
When telephoto-middle tracking adjustment is to be performed for a lens having the locus Sa with an error, the focus lens is lowered from a start point {circle around (1)}′ for adjustment downward in FIG. 27 by the design value A, thereby obtaining a position {circle around (2)}′.
In a similar manner, the variable power lens is moved to an in-focus position. Consequently, a telephoto end Ta can be determined at a position {circle around (1)}, and a wide end Wa can be determined at a position {circle around (1)}. In this case, variations in focal length are generated. However, since the error of the locus Sa can be absorbed during zooming, a zooming operation free from a blur can be realized.
In fixed stroke adjustment, the stroke and the balance are adjusted to be predetermined values regardless of whether the locus Sb corresponding to the design value is exhibited or the locus Sa with an error is obtained. In both the cases, the telephoto end position is {circle around (1)}, and the wide end position is {circle around (1)}, so no variations in focal length are generated. However, the error of the locus Sa cannot be completely absorbed, and the locus Sb is traced during the zooming operation, resulting in a blur corresponding to the error.
However, the camera system as described above has a function of controlling automatic focusing in the camera main body, and its lens assemblies are interchangeable. When the response for automatic focusing or the like is determined to be optimum for a specific lens, another lens may not exhibit optimum performance. Hence, it is difficult to set optimum performance for all attachable lenses.
A technique of transmitting a focus signal necessary to execute focusing from the camera main body to the lens assembly while the function of controlling automatic focusing is assigned to the lens assembly side has been proposed.
In this case, a means for determining the size of an extraction area where a focus signal is extracted from a video signal is arranged on the lens assembly side such that the optimum response for automatic focusing for all connectable lenses can be determined. The size information is transferred to the main body side, and an appropriate size is set in correspondence with the focal length of each lens, thereby optimizing the focus signal level obtained from the camera main body.
Assume that the extraction area is fixed with respect to the frame size regardless of the types of lenses. For a wide angle lens, various objects are present in the area, so that the focus signal level tends to be high. For a high-luminance object, the signal obtained by an image sensing device is saturated, so focusing can hardly be appropriately performed. For a telephoto lens, an object image is enlarged, so that the focus signal level tends to be low. For a low-luminance object, resultant AF characteristics do not exhibit a desired result.
However, in a camera whose lenses are interchangeable and whose function of controlling automatic focusing as in the prior art is arranged in the lens assembly, the image sensing state on the main body side cannot be recognized by the automatic focusing means in the lens assembly, resulting in the following problems.
{circle around (1)} When a sensing operation is performed using an illumination equipment such as a home fluorescent lamp using discharge as a light source, discharge repeatedly occurs or stops depending on the frequency of the AC power supply of the light source, i.e., a so-called flicker is generated, so the output level of the image sensing signal sometimes periodically changes. However, the presence/absence of a flicker cannot be recognized on the lens assembly side. During focusing, it can hardly be determined whether the change in AF evaluation value is caused by the movement of the focusing lens or by a flicker, so the in-focus direction may be erroneously set.
When, to eliminate the influence of a flicker, the timing for driving the lens or fetching the AF evaluation value is always synchronized with the flicker period, the AF response becomes slow.
{circle around (2)} When a low-luminance object is to be taken, the image sensing signal is amplified by AGC. At this time, noise is also amplified, and many noise components are contained in the AF evaluation value. The amplification amount is unknown on the lens assembly side, so an erroneous operation is caused by the influence of noise in reactivation determination for a focusing operation or determination of a hill-climbing direction, often resulting in a blur.
{circle around (3)} In a sensing operation using a so-called program mode in which the iris stop, the shutter, AGC, and the like are automatically adjusted to realize effective sensing, and an optimum sensing state is realized, the exposure state changes depending on a change in mode. However, the change in mode cannot be recognized on the lens assembly side.
When the program mode changes, the AF evaluation value also changes to result in an erroneous AF operation. Particularly, when the mode changes in an in-focus state to forcibly open the iris stop for a photographic effect, the depth of field becomes small. However, when the field angle is wide, or when a high-luminance object is to be taken, an overexposure state is set, and the image sensing signal level may exceed the dynamic range of the image sensing device. At this time, the AF evaluation value does not change before and after the mode change. Therefore, an out-of-focus state is easily generated because of the decreased depth of field.
The lens assembly itself drives the iris stop in accordance with a control command from the camera main body, so that the iris stop state can be recognized. However, it cannot be determined whether the iris stop state optimizes exposure or aims a photographic effect.
If the iris stop state changes, the focusing operation may be reactivated to eliminate the above disadvantages. However, if the reactivation operation is performed every time the iris stop state changes, the AF operation is performed restlessly. {circle around (4)} In sensing using a so-called slow shutter, i.e., when the charge accumulation time in the image sensing device is prolonged to an integral multiple of the normal accumulation time, and an image sensing signal is intermittently read out, the focus signal sent from the camera main body is not updated for a time corresponding to the read period. However, the read period is unknown on the lens assembly side. Since the focus signal does not change for a predetermined time, erroneous determination of an in-focus state is made, or the hill-climbing direction is erroneously determined. {circle around (5)} In sensing using an enlargement function such as electronic zooming, the enlargement magnification and the position of enlargement in a picture frame cannot be recognized on the lens assembly side. In some cases, the focus signal extraction area becomes larger than the enlarged area. At this time, focusing is sometimes performed with respect to an object-outside-the monitor.
When the picture frame is enlarged, even a blur within the depth of field becomes visible. Therefore, a blur generated by a fine driving operation such as a wobbling operation which is performed to determine an in-focus direction becomes visible.
Additionally, the design value A necessary for the focusing operation must be set in correspondence with each interchangeable lens.
When a new lens assembly is developed, an old camera main body may not perform sufficient control.
A rear focus lens has a lot of complex cam loci, and the lens must accurately trace these loci. For this reason, the positions of the zoom lens and the focus lens must be accurately detected. For this purpose, a technique of performing feedback loop control using an encoder for position detection is available. However, a highly precise encoder is expensive and also requires a space.
A technique has been proposed instead in which the lens is driven by a stepping motor, and a moving amount of the stepping motor from a reference position is detected by counting supplied step pulses. According to this technique, the stepping motor is controlled by the microcomputer. Therefore, only by increasing/decreasing the counter value in the microcomputer, the function of an encoder can be realized, though it is open-loop control.
However, at the start time, an initialization operation must be performed to temporarily drive the lens to the reference position and reset the counter. If the power supply is turned off, and the microcomputer is reset, the contents in the counter are cleared, so that the control information including the absolute positions of the variable power lens and the compensating lens also returns to an initial value.
Therefore, even when a focusing operation is completed before the power supply is turned off, a deviation from the in-focus state is generated at the time of repowering.
In addition, when a zooming operation is performed in this state, a cam locus different from that before turning off the power supply is traced because the absolute lens position information changes. For this reason, the focusing operation must be performed again every time the power supply is turned on.
To manage the compensating lens and the variable power lens with a microcomputer, the positions of the focus lens and the variable power lens must always be recognized as absolute positions. Therefore, when the power supply is turned on, the initialization operation must be performed. When the power supply is turned off, a post-processing operation-must be-performed.
When the power supply is turned on, the focus lens or the variable power lens is moved to the infinite end or the wide end as a predetermined position (reset position), and the absolute position is recognized by the lens microcomputer such that the position matches P( 0 , 0 ) in FIG. 26 .
This is the initialization operation for the focus lens or the variable power lens. To perform the initialization operation at a high speed, the position of the focus lens or the variable power lens is stored in the microcomputer as post-processing at the time of turning off the power supply, and the focus lens or the variable power lens is moved close to the reset position. At the time of repowering, the initialization operation is performed, and then, the focus lens or the variable power lens is moved again to the position stored in the lens microcomputer. With this operation, sensing can be started in the same situation as before turning off the power supply.
However, when the power supply circuit of the lens is immediately turned on/off in a manner interlocked with the ON/OFF operation of the power which is supplied from the camera main body, when a video signal is output simultaneously with the ON operation of the power supply of the camera main body, or when the operating members arranged on the lens side are enabled simultaneously with the ON operation of the power supply of the camera main body, sensing is started before the lens initialization operation is completed, resulting in a blur in image or a degradation in image quality. In addition, if the power supply is turned off before lens post-processing is completed, control is confused at the time of repowering, and a long time is required to restore a normal state.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems, and has as its object to provide an interchangeable lens video camera system which can stably focus on a main target object under any conditions of the object or the environment.
According to the present invention, there are provided a video camera system, and a camera and a lens assembly, which constitute the system, as will be described below.
That is, there is provided a camera detachably having a lens assembly including a lens for forming an image of an object and lens control means for controlling the lens, comprising:
image sensing means for converting the image of the object into an image signal and outputting the image signal; and
control means for generating information associated with an image sensing state of the object on the basis of the image signal obtained by the image sensing means and transmitting the information to a lens assembly.
There is also provided a lens assembly detachably attached to a camera having image sensing means for photoelectrically converting incident light to sense an image and outputting an image signal, comprising:
a lens for forming an image of an object;
memory means which stores locus information of the lens in advance; and
control means for receiving information associated with an image sensing state of the object from the camera and controlling the lens on the basis of the locus information and evaluation information representing a focus state of the image signal included in the information associated with the image sensing state.
Preferably, the memory means stores design position information of the variable power lens and the focus lens and the control means further comprises adjusting means for adjusting an operation of the focus lens on the basis of the position information to compensate for a movement of an in-focus point caused by the zooming operation of the variable power lens.
For example, the adjusting means-adjusts an operation stroke of the variable power lens to change a telephoto end position and a wide end position, and calculates a position of the variable power lens, at which an in-focus position of the focus lens and a moving amount of the focus lens from the telephoto end position equal those of the design position information, thereby changing the telephoto end position and the wide end position.
There is also provided a camera detachably having a lens assembly, comprising:
image sensing means for photoelectrically converting incident light to sense an image and transmitting an image signal to the lens assembly.
There is also provided a lens assembly detachably attached to a camera having image sensing means for sensing an image of an object and outputting an image signal, comprising:
a variable power lens for performing a zooming operation;
a focus lens for performing a focusing operation and compensating for a movement of an in-focus point caused by the zooming operation of the variable power lens;
memory means which stores position information of the variable power lens and the focus lens;
focus detection means for receiving the image signal and extracting, from the image signal, evaluation information which changes in accordance with a focus state; and
control means for controlling the variable power lens and the focus lens on the basis of the position information stored in the memory means and the evaluation information obtained by the focus detection means.
Preferably, the image signal is normalized in accordance with the focus state.
There is also provided a lens assembly detachably attached to a camera having image sensing means for sensing an image of an object and outputting an image signal, comprising:
a variable power lens for performing a zooming operation;
a focus lens for performing a focusing operation and compensating for a movement of an in-focus point caused by the zooming operation of the variable power lens;
first memory means for storing position information of the variable power lens and the focus lens;
control means for controlling the variable power lens and the focus lens; and
second memory means for storing current position information of the variable power lens and/or the focus lens,
wherein the control means determines, upon turning on a power supply of the lens assembly, whether the camera to which the lens assembly is mounted is the same as that in a previous operation, and if the camera is the same as that in the previous operation, the control means restores an operation state of the variable power lens and/or the focus lens at the time of turning off the power supply on the basis of the current position information stored in the memory means.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a block diagram showing the arrangement of an interchangeable lens video camera system according to the first embodiment of the present invention;
FIG. 2 is a block diagram showing the detailed internal arrangement of an AF signal processing circuit 113 and an AE signal processing circuit 131 in a camera signal processing circuit 112 and a main body microcomputer 114 according to the first embodiment of the present invention;
FIGS. 3A and 3B are views for explaining electronic zooming and control of a distance measurement frame according to the electronic zooming operation in the first embodiment of the present invention;
FIGS. 4A to 4 C are views for explaining a photometry area setting operation in the first embodiment of the present invention;
FIGS. 5A to 5 C are graphs for explaining variations in image sensing signal level caused by a flicker in the first embodiment of the present invention;
FIG. 6 is a flow chart for explaining AF control by the microcomputer 114 in the camera main body in the first embodiment of the present invention;
FIG. 7 is a graph for explaining a wobbling operation for determining a focus lens driving direction in the AF operation of the first embodiment of the present invention;
FIGS. 8A to 8 C are graphs for explaining the wobbling operation considering a countermeasure to a flicker in the first embodiment of the present invention;
FIG. 9 is a flow chart for explaining processing performed when a program mode changes during the AF operation in the first embodiment of the present invention;
FIG. 10 is a block diagram showing the arrangement of an interchangeable lens video camera system according to the second embodiment of the present invention;
FIG. 11 is a block diagram showing the internal arrangement of an AF signal processing circuit on a camera main body side in the second embodiment of the present invention;
FIG. 12 is a view for explaining an operation and timing of extracting various focus evaluation values in the second embodiment of the present invention;
FIG. 13 is a flow chart for explaining an AF operation according to the second embodiment of the present invention;
FIG. 14 is a flow chart for explaining an in-focus state adjustment operation according to the second embodiment of the present invention;
FIG. 15 is a block diagram showing the arrangement of an interchangeable lens video camera system according to the third embodiment of the present invention;
FIG. 16 is a block diagram showing the internal arrangement of an AF signal processing circuit on a lens assembly side in the third embodiment of the present invention;
FIG. 17 is a block diagram showing the arrangement of an interchangeable lens video camera system as a modification of the third embodiment of the present invention;
FIG. 18 . is a block diagram showing the arrangement of an interchangeable lens video camera system according to the fourth embodiment of the present invention;
FIG. 19 is a flow chart for explaining an operation in the lens microcomputer of the interchangeable lens video camera according to the fourth embodiment of the present invention;
FIG. 20 is a flow chart for explaining an operation in the lens microcomputer of an interchangeable lens video camera as the first modification of the fourth embodiment of the present invention;
FIG. 21 is a block diagram showing the arrangement of an interchangeable lens video camera system as the second modification of the fourth embodiment of the present invention;
FIG. 22 is a block diagram showing the arrangement of an interchangeable lens video camera system according to the fifth embodiment of the present invention;
FIG. 23 is a time chart showing the sequence of turning on/off the power supply in the fifth embodiment of the present invention;
FIG. 24 is a block diagram showing the typical arrangement of a conventional interchangeable lens video camera;
FIG. 25 is a view showing the basic arrangement of an inner focus type lens system;
FIG. 26 is a graph showing focus lens moving loci (lens cam data) for correcting the position of a focal plane which is displaced in accordance with the zooming operation of a variable power lens to maintain an in-focus state;
FIG. 27 is a graph for explaining an adjustment operation for correcting an error between a can locus stored in the lens cam data and an actual lens position;
FIG. 28 is a graph for explaining calculation for interpolating a cam locus which is not stored from a plurality of cam locus information stored in the lens cam data;
FIG. 29 is a graph for explaining calculation for interpolating a cam locus which is not stored from a plurality of cam locus information stored in the lens cam data;
FIGS. 30A and 30B are graphs for explaining an algorithm for causing a focus lens to trace a locus; and
FIG. 31 is a table for explaining the internal structure of the lens cam data.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described in detail in accordance with the accompanying drawings.
First Embodiment
FIG. 1 is a block diagram showing the arrangement of an embodiment of the present invention. A lens assembly 127 can be separated from a camera main body 128 to constitute a so-called interchangeable lens system.
Light from an object passes through a fixed first lens group 101 , a second lens group 102 (to be referred to as a variable power lens hereinafter) for performing a zooming operation, an iris stop 103 , a fixed third lens group 104 , and a fourth lens group (to be referred to as a focus lens hereinafter) 105 having both a focusing function and a compensator function of compensating for the movement of a focal plane caused by the zooming operation, forms an image on the image sensing surfaces of an image sensing device 106 such as a CCD for taking a red component in the three primary colors of red (R), green (G), and blue (B), an image sensing device 107 such as a CCD for taking a green component, and an image sensing device 108 such as a CCD for taking a blue component, and is photoelectrically converted. Image sensing signals corresponding to the respective color components, i.e., the red, green, and blue components are output.
The image sensing signals of the respective color components output from the image sensing devices are amplified to their optimum levels by amplifiers 109 , 110 , and 111 , respectively, input to a camera signal processing circuit 112 , and converted into a standard TV signal. The image sensing signals are also input to an AWB (Auto White Balance) signal processing circuit 130 , an AE (Auto Exposure) signal processing circuit 131 , an AF (Auto Focus) signal processing circuit 113 , and a flicker detection circuit 115 in the camera signal processing circuit 112 .
Color difference signals SAWB generated by the AWB signal processing circuit 130 are supplied to an AWB/exposure control unit 135 in a microcomputer 114 for controlling the camera main body 128 . The amplifiers 109 , 110 , and 111 are controlled such that the color difference signals become zero, so that white balance control is performed. At the same time, the control information is sent to a microcomputer 116 in the lens assembly 127 as color temperature information.
A photometry signal SAE generated by the AE signal processing circuit 131 is sent to the AWB/exposure control unit 135 and used for exposure control. At the same time, a photometry area control command for performing photometry only in a partial area of a frame is sent to the AE signal processing circuit 131 .
The AWB/exposure control unit 135 also performs exposure control. The AWB/exposure control unit 135 drives a CCD driving circuit 136 such that a photometry signal is set in a desired exposure state, and sends the accumulation times of the image sensing devices 106 , 107 , and 108 , the gains of the amplifiers 109 , 110 , and 111 , or an iris stop driving command to an iris stop control unit 120 of the lens microcomputer 116 , thereby performing feedback control of the amount of light passing through the iris stop 103 .
Control of the iris stop 103 is performed in the following manner. The iris stop control unit 120 sends a signal to an iris driver 124 in accordance with an iris stop driving command which is sent from the camera main body 128 to drive an IG (Iris Garvano) meter 123 . The state of the driven iris stop is detected by an encoder 129 . An output signal from the encoder is transferred to the AWB/exposure control unit 135 in the microcomputer 114 through the iris stop control unit 120 , thereby controlling the iris stop 103 .
The AWB/exposure control unit 135 also controls a program mode while placing an importance on exposure control. When a photographer operates a program mode switching unit 138 and selects a mode, the AWB/exposure control unit 135 controls parameters including an iris stop mechanism, an amplifier for AGC or the like, and an electronic shutter in accordance with the selected mode, thereby realizing an optimum exposure state for an object or sensing situation.
The AWB/exposure control unit 135 also controls a slow shutter function for taking a low-luminance object. The slow shutter function is a function of controlling, in accordance with the slow shutter speed selected by a slow shutter switching unit 139 , the CCD driving circuit 136 to prolong the charge accumulation times of the image sensing devices 106 , 107 , and 108 and intermittently extracting an image sensing signal while synchronizing the read period with the charge accumulation time (for an electronic shutter, the accumulation time changes though the read period does not change).
The readout intermittent image sensing signal is received by a field memory 132 through the camera signal processing circuit 112 . The AWB/exposure control unit 135 controls a memory control/interpolation circuit 133 to transfer stored video information to the camera signal processing circuit 112 , thereby compensating for video information of fields which are omitted for the read period.
The AWB/exposure control unit 135 performs the above-described exposure control, program mode control, and slow shutter control and also sends electronic shutter information as exposure information, amplification factor information of AGC or the like, iris stop control information, selected program mode information, or read period information in slow shutter control to the lens microcomputer 116 in the lens assembly.
An AF evaluation value generated by the AF signal processing circuit 113 is transferred to the lens microcomputer 116 through the microcomputer 114 . The information of a distance measurement area in a frame, which is determined as a frame for measuring a distance to an object by a distance measurement frame size control unit 142 in the lens microcomputer 116 and sent to the AF signal processing circuit 113 through the main body microcomputer 114 .
The distance measurement frame size control unit 142 determines a distance measurement area having an optimum size to obtain AF performance in accordance with the focal length of the lens assembly 127 to be mounted. The reason why the size of the distance measurement frame is determined in the lens assembly has been described above.
The main body microcomputer 114 reads out the state of a zoom switch unit 137 (a unit for outputting a voltage corresponding to a resistance value which changes in accordance with the operation of a rotary operation member: when the output voltage is A/D-converted, the direction and amount of rotation of the operation member can be obtained as digital signals) and the state of an AF switch 141 , and sends the states of the switches to the lens microcomputer 116 .
Upon receiving the information from the main body microcomputer 114 , which represents that the AF switch 141 is OFF (manual focus mode), and the zoom switch unit 137 is depressed, the lens microcomputer 116 sends a control signal to a zoom motor driver 122 while referring to lens cam data 119 by operating an AF/computer zoom control program 117 such that the lens is driven in a direction corresponding to the depressed state of the switch, i.e., to the telephoto side or the wide side. With this operation, the variable power lens 102 is driven through a zoom motor 121 so that a zooming operation is performed. A control signal is also sent to a focus motor driver 126 . With this operation, the focus lens 105 is driven through a focus motor 125 so that a shift of the focal position caused by the zooming operation is compensated for.
When the AF switch 141 is ON (auto mode), and the zoom switch unit 137 is depressed, the in-focus state must be maintained for both the zooming operation and a change in object distance. The lens microcomputer 116 performs the zooming operation while referring to an AF evaluation value signal sent from the microcomputer 114 by operating the AF/computer zoom control program 117 , and maintaining a position where the AF evaluation value is maximized.
When the AF switch 141 is ON, and the zoom switch unit 137 is not depressed, the AF/computer zoom control program 117 sends a signal to the focus motor driver 126 to drive the focus lens 105 through the focus motor 125 that the AF evaluation value signal sent from the main body microcomputer 114 is maximized, thereby performing an automatic focusing operation.
A flicker signal SFL generated by the flicker detection circuit 115 in the camera signal processing circuit 112 in the camera main body 128 is sent to the main body microcomputer 114 . The presence/absence of a flicker is determined, and flicker presence/absence information is sent to the lens microcomputer 116 .
The flicker signal SFL will be described with reference to FIGS. 5A to 5 C. FIGS. 5A to 5 C are graphs showing a flicker observed when the frequency of an AC power supply is 50 Hz, and the output signal of the video camera is based on the NTSC standard, i.e., the vertical sync frequency is 60 Hz, and a change in output from an image sensing device.
FIG. 5A shows a change in absolute voltage of an AC power supply with respect to time. The AC power supply waveform is a sine wave. Therefore, for the absolute voltage, the waveform of the positive portion of the sine wave is repeated at a period of 100 Hz.
FIG. 5B shows the discharge repeating phenomenon of a fluorescent lamp. A fluorescent lamp starts discharge when the absolute value of the power supply voltage exceeds a predetermined value, i.e., VTH in FIG. 5A, and stops discharge when the absolute voltage is smaller than the value VTH. Therefore, the light-emitting amount changes at a period of 100 Hz, as shown in FIG. 5 B.
FIG. 5C shows a change in charge amount accumulated in an image sensing device every 1V (vertical scanning period). The image sensing device repeats charge accumulation every 1V, i.e., at a period of 60 Hz.
For a period V 1 shown in FIG. 5C, the fluorescent lamp performs the discharge operation almost twice. However, for a period V 2 , the discharge operation is performed one and ⅔ times. For a period V 3 , the discharge operation is performed one and ⅓ times. Since the light amount changes in this manner, the charge accumulation amount also changes as shown in FIG. 5 C.
The flicker detection circuit 115 shown in FIG. 1 may detect a change in image sensing signal level as shown in FIG. 5C or extract a component of 20 Hz corresponding to the light amount change period shown in FIG. 5C by using a bandpass filter or the like.
If a flicker signal is defined as the former, the main body microcomputer 114 detects the signal change period to determine the presence/absence of a flicker. If a flicker signal is defined as the latter, i.e., the level signal of a specific frequency component, the main body microcomputer 114 determines whether the level of the flicker signal is equal to or higher than a predetermined level, thereby determining the presence/absence of a flicker.
A video signal processed by the camera signal processing circuit 112 shown in FIG. 1 is stored in the field memory 132 . The memory control/interpolation circuit 133 controls the memory to read out the stored image, and outputs an enlargement signal obtained by enlarging the image along the vertical and horizontal directions while performing interpolation between the scanning lines and between pixels.
The enlargement signal read out from the field memory 132 under the control of the memory control/interpolation circuit 133 is subjected to color processing by the camera signal processing circuit 112 again and converted into a standard TV signal.
The memory control/interpolation circuit 133 performs control in accordance with the enlargement magnification information from an electronic zoom control unit 134 in the main body microcomputer 114 . The electronic zoom enlargement magnification information from the electronic zoom control unit 134 is sent to the lens microcomputer 116 .
The distance measurement frame size control unit 142 in the lens microcomputer 116 changes the size of the distance measurement frame on the basis of the enlargement magnification information sent from the main body microcomputer 114 (to be described later in detail with reference to FIG. 3 ). The size information is sent to the AF signal processing circuit 113 through the main body microcomputer 114 .
The AF signal processing circuit 113 and the AE signal processing circuit 131 will be described below in detail with reference to FIG. 2 . The image sensing device outputs of red (R), green (G), and blue (B), which are amplified to optimum levels by the amplifiers 109 , 110 , and 111 , respectively, are converted into digital signals by A/D converters 206 , 207 , and 208 , respectively, and sent to the camera signal processing circuit 112 . These signals are appropriately amplified by amplifiers 209 , 210 , and 211 , respectively, and added by an adder 212 to generate a luminance signal S 5 .
The luminance signal S 5 is input to a bandpass filter 213 , and only a high-frequency component whose signal level changes in accordance with the focus state is extracted. Only the signal of scanning lines in a specific image area (area in the distance measurement frame) in a picture frame is gates by a gate circuit 214 , and the peak value is held by a peak hold circuit 215 . Upon completion of gate processing in one field, a peak value S 6 of a focus signal is transferred to the lens microcomputer 116 through the main body microcomputer 114 , so that the peak hold circuit 215 is initialized.
ON/OFF control of the gate circuit 214 is performed by a gate timing generation circuit 222 and a gate pulse control circuit 216 . On the basis of information S 10 from the distance measurement frame size control unit 142 in the lens microcomputer 116 , the main body microcomputer 114 determines an extraction start position CR 1 and an end position IR 1 of a distance measurement frame as indicated by reference numeral 303 in FIG. 3 A. ON/OFF control of the gate circuit is performed on the basis of information S 12 .
The luminance signal S 5 is also input to the AE signal processing circuit 131 . The luminance signal S 5 input to the AE signal processing circuit 131 is divided into an averaged overall light reading signal S 7 a obtained by detection of the entire video area, as shown in FIG. 4A, and a center-weighted light reading signal S 7 b obtained by detection of only the central portion of the video area, as shown in FIG. 4 B. These signals are weighted by weighting circuits 217 and 219 , respectively, added by an adder 221 , and sent as a photometry evaluation value S 8 to an exposure control arithmetic unit 231 in the AWB/exposure control unit 135 . Control of ON/OFF timing or weighting ratio of a gate circuit 218 for performing center-weighted light reading is performed on the basis of information from the exposure control arithmetic unit 231 .
An exposure control operation will be described below using an example of exposure control in a program mode. Control parameters for determining exposure include parameters of the iris stop mechanism, AGC, and the electronic shutter. Data with these parameters set in units of program modes in accordance with an object or sensing situation are prepared as look-up tables (LUTS) in the AWB/exposure control unit 135 . There are LUT 1 ( 227 ) corresponding to program mode 1 , LUT 2 ( 228 ) corresponding to program mode 2 , LUT 3 ( 229 ) corresponding to program mode 3 , and LUT 4 ( 230 ) corresponding to program mode 4 .
The AWB/exposure control unit 135 reads out the data of a look-up table corresponding to the program mode set by the program mode switch unit 138 into an LUT data control unit 226 and controls the parameters on the basis of the data, thereby enabling the program mode.
When the object moves at a high speed, an electronic shutter control unit 224 controls the image sensing device (CCD) driving circuit 136 such that the electronic shutter for controlling the accumulation time of an image sensing device is set at a high speed with priority. With this processing, a sensing mode excellent in dynamic resolution, i.e., a so-called “sport mode” can be set.
When an iris stop control unit 225 transfers an iris stop driving command to the lens microcomputer 116 to set the iris stop mechanism to the open side with priority, and exposure control is performed on the basis of the remaining parameters, the depth of field becomes small. With this processing, an effect of vignetting the background is obtained. That is, a so-called “portrait mode” suitable for taking a person or the like can be set.
In this manner, a sensing operation optimum for the sensing situation can be realized.
When the AE signal processing circuit 131 controls the photometry distribution by setting the detection area or detection position of the video signal for exposure control set by a gate pulse control circuit 220 , a more optimum sensing operation can be performed.
For example, so-called averaged overall light reading in which the entire video area is detected, as shown in FIG. 4A, and exposure control is performed such that the detection signal reaches a predetermined level, or center-weighted light reading in which only the central portion of the video area is detected, as shown in FIG. 4B, and exposure control is performed such that the detection signal reaches a predetermined level can be performed.
In the AE signal processing circuit 131 , the detection data of the overall light reading area and the detection data of the center-weighted light reading area are weighted by the weighting circuits 217 and 219 , respectively. Exposure control is performed on the basis of the detection data obtained by adding the above data at a predetermined ratio. With this processing, exposure control based on photometry which combines averaged overall light reading and center-weighted light reading can be performed.
When the weighting ratio is changed for each program mode in accordance with the object or sensing situation, more optimum exposure control can be performed using the advantages of the two photometry techniques.
For example, for an object illuminated with a spot light with a dark background, or for a backlighted object, weighting of center-weighted light reading is increased to adjust the ratio to averaged overall light reading. With this processing, proper exposure control can be performed for not only the main object but also an object such as the background.
The picture frame is divided, as shown in FIG. 4C, and video detection is performed in each area. The area of the detection data used for exposure control is limited, or weighting is changed in units of program modes in accordance with the object or sensing situation. With this processing, fine exposure control can be realized.
An example of automatic focusing control in a lens assembly will be described below with reference to FIG. 6 . The flow chart of FIG. 6 shows an algorithm for the automatic focusing operation of the AF/computer zoom control program 117 , which is performed when the lens microcomputer 116 in the lens assembly does not perform a zooming operation.
Referring to FIG. 6, AF control processing is started in step S 601 . In step S 602 , the above-described wobbling operation for determining a hill-climbing direction is performed. The wobbling operation will be described below with reference to FIG. 7 .
FIG. 7 is a graph showing a change in characteristic curve 701 of an AF evaluation value which is obtained when the focus lens is moved relative to a certain object from the infinity side to the closest focusing distance. The abscissa indicates the position of the focus lens, and the ordinate indicates an AF evaluation value level.
An in-focus point is indicated by reference numeral 702 , where the AF evaluation value level is maximized (an in-focus lens position is indicated by reference numeral 708 ). The focus lens position is controlled such that the AF evaluation value level is always maximized.
In the wobbling operation, the focus lens is finely vibrated, and it is determined from the variation in signal level whether the in-focus point is present in the direction of the closest focusing distance or on the direction of infinity with respect to the current focus lens position.
In the wobbling operation, the AF evaluation value is fetched while finely driving the focus lens, thereby determining whether the current state is an in-focus state or a blurred state (if there is a blur, it is determined whether the focus point deviates from the in-focus state in the direction of infinity or in the direction of the closest focusing distance).
For example, when the current focus position is on the infinity side with respect to the in-focus point (e.g., at a position indicated by reference numeral 709 in FIG. 7 ), a wobbling operation is executed to finely drive the lens from the direction of infinity (the focus lens position is moved as indicated by reference numeral 703 : the time axis is set from the upper side to the lower side with respect to the sheet surface). A change in AF evaluation value level observed at that time is indicated by reference numeral 704 .
When the focus lens position is on the closest focusing distance side with respect to the in-focus point (e.g., at a position indicated by reference numeral 710 in FIG. 7 ), the lens is finely driven as indicated by reference numeral 705 . A change in AF evaluation value level is indicated by reference numeral 706 .
The phase of the change in AF evaluation value level indicated by reference numeral 704 opposes that indicated by reference numeral 706 . By determining this phase, the side on which the focus lens is positioned with respect to the in-focus point, i.e., the direction to which the focus lens must be moved can be known.
When the lens is finely driven at the peak of the mountain-like characteristic curve 701 of the AF evaluation value ( 711 ), a resultant change in AF evaluation value level ( 712 ) has a small amplitude and a different shape, so that a blur or an in-focus state can be detected.
In the wobbling operation near the in-focus point, a blur is visible to the photographer depending on the driving amplitude amount (a in FIG. 7) of fine drive of the focus lens. Therefore, a minimum amplitude amount for obtaining a sufficient evaluation value must be set.
Near the base of the mountain-like characteristic curve 701 , even when the focus lens is finely driven, the amplitude of the AF evaluation value may not be sufficiently obtained in some cases, so the direction cannot be determined. Therefore, the lens driving amplitude is preferably set to be relatively large.
In an actual wobbling operation, instead of driving the lens along a sine wave, as indicated by reference numerals 703 , 711 , and 705 , the focus lens at, e.g., the position 709 is driven by the distance ain the direction of infinity, and the AF evaluation value is fetched (the evaluation value level corresponds to a point 714 ). Thereafter, the lens is driven by 2 a to the closest focusing distance indicated by reference numeral 715 , and an evaluation value is fetched at a position 715 (the level corresponds to a point. 716 ). The level difference is defined as a driving direction evaluation value. When the driving direction evaluation value has an absolute value amount larger than a noise amount, the hill-climbing direction is determined in accordance with the sign of the driving direction evaluation value.
With a wobbling operation near the in-focus point, i.e., at the position 702 , the level of the obtained driving direction evaluation value may be insufficient. However, since the differential amount between the evaluation value before the start of the wobbling operation and the AF evaluation value obtained during the wobbling operation can be detected, and the evaluation value level at this time is high, it can be determined whether the lens is positioned at the in-focus point (since the evaluation value level is high, the influence of the noise component is minimized, so that the above-described significant signal change amount can be made smaller than that at the base of the mountain).
Referring back to the flow chart of FIG. 6, it is determined in step S 603 from the result of the wobbling operation in step S 602 whether the current sensing state is an in-focus state or a blurred state. If it is determined that an in-focus state is set, the focus lens is stopped, and the flow advances to a reactivation monitor processing routine starting from step S 609 .
If it is determined in step S 603 that an out-of-focus state is set, a wobbling operation is performed in step S 604 to determine the direction of the in-focus point, and hill-climbing processing is executed in the direction of the determination result (step S 605 ).
In step S 606 , it is determined whether the peak of the in-focus point, i.e., the in-focus evaluation signal is passed. If NO in step S 606 , hill-climbing processing is continued. If YES in step S 606 , the focus lens is returned to the peak (steps S 607 and S 608 ).
During this hill-climbing operation, the hill-climbing speed is controlled in accordance with the shape of the mountain while always monitoring the shape (the lens is driven at a high speed near the base of the mountain, though the driving speed is gradually decreased toward the peak).
When the focus lens is returning to the peak, the object sometimes changes due to panning or the like. Therefore, when the focus lens arrives at the peak, the flow returns to step S 602 to determine whether the focus lens is properly present at the peak, i.e., in-focus point, so that the wobbling operation is performed again.
If it is determined in step S 603 that an in-focus state is set, the flow advances to the reactivation monitoring routine starting from step S 609 . In step S 609 , the AF evaluation value level in the in-focus state is stored.
In step S 610 , reactivation determination is performed.
This processing will be described in detail with reference to FIG. 7 . As shown in FIG. 7, assume that the focus lens is at the position 708 , and the AF evaluation level at that time is indicated by reference numeral 702 . This level 702 corresponds to the AF evaluation value level stored in step S 609 .
Assume that the evaluation value level is lowered from 702 to 707 due to a change in object or the like. Whether reactivation is to be executed is determined in the following manner.
When the evaluation value level changes from the level 702 by a reactivation determination threshold value β or more shown in FIG. 7, it is determined that a deviation from the in-focus state is generated, and reactivation is executed. If the change amount of the evaluation value is smaller than the reactivation determination threshold value β, it is determined that reactivation is not executed.
Referring back to the flow chart of FIG. 6, the determination result in step S 610 in FIG. 6 is determined in step S 611 . If reactivation is not executed, the focus lens is stopped (step S 612 ), and the flow returns to step S 610 to perform reactivation monitoring again.
If it is determined that reactivation is to be executed, the flow returns to step S 602 . The wobbling operation is performed again to determine the focus lens moving direction. By repeating these operations, the focus lens is operated such that the in-focus state is always maintained.
In the loop of the automatic focusing operation, the AF evaluation value is normally generated in synchronism with the vertical sync signal period. The AF control routine is also performed in synchronism with the vertical sync signal period accordingly.
The reason for this is that the latest focus signal information can be effectively used to increase the AF response.
The algorithm of the focusing operation by a specific lens has been described above. For other lenses, the degree of speed control, the wobbling amplitude amount, or parameters used for in-focus determination/reactivation determination can be optimized in accordance with the characteristics of the individual lenses. Consequently, under various conditions of the object or environment, a stable AF operation for a main target object can be realized.
A characteristic feature of the present invention, i.e., a technique of using sensing state information transferred from the main body microcomputer 114 to the lens assembly 127 side for AF control will be described below.
First, in accordance with flicker presence/absence information (if the camera main body has no flicker detection circuit, the presence/absence of a flicker can be recognized from color temperature information and electronic shutter information), the lens driving timing and the AF evaluation value receiving timing are changed to eliminate the influence of the flicker, thereby preventing an erroneous AF operation.
Processing of preventing an erroneous AF operation will be described with reference to FIGS. 8A to 8 C by using, as an example, a wobbling operation performed in step S 602 in FIG. 6 . FIG. 8A corresponds to FIG. 5C with its time axis extended and shows a periodical change in level caused by a flicker.
FIG. 8C shows a time change in focus position observed when a normal wobbling operation is repeated. As shown in FIG. 8C, in the wobbling operation, the focus lens is driven to the closest focusing distance at a predetermined amplitude. When the focus lens reaches a predetermined focus position 801 , driving is stopped. When the focus lens is set in a still state, charges are accumulated in an image sensing device for a period of 1V. For the next vertical sync signal period, the video signal accumulated for a period V 1 is read out from the image sensing device, thereby obtaining the AF evaluation value at the focus position 801 .
The focus lens is driven to a predetermined focus position 802 in the direction of infinity. Similarly, for a period V 4 , charges accumulated for a period V 3 are read out, thereby obtaining the AF evaluation value at the focus position 802 .
When the wobbling operation is performed as shown in FIG. 8C, and a flicker is present, the obtained AF evaluation value varies due to the influence of the flicker, so the direction of the in-focus point cannot be properly determined.
Only when a flicker is present, the wobbling operation period is synchronized with the flicker period, as shown in FIG. 8 B. By receiving the AF evaluation value used to determine the direction at timings of V 1 , V 4 , V 7 , V 10 , . . . , V 2 , V 5 , V 8 , V 11 , . . . , or V 3 , V 6 , V 9 , V 12 free from a change in light amount, the influence of a flicker is eliminated.
In FIG. 8B, the AF evaluation values for the periods V 2 and V 5 are received. However, the present invention is not limited to this. Determination may also be made using a combination V 1 +V 2 , or V 4 +V 5 .
In FIG. 8B, the wobbling operation period is represented by 3V. However, to eliminate the influence of a flicker, any period can be used as long as the period is an integral multiple of the period of the video signal output change caused by a flicker.
As described above, when a flicker is present, control as shown in FIG. 8B is performed. With this processing, proper direction determination is performed while eliminating the influence of the flicker. When no flicker is detected, the wobbling operation is completed as fast as possible, as shown in FIG. 8C, thereby improving the AF response.
Second, amplification factor information of AGC or the like is used. In the wobbling operation shown in FIG. 7, a driving direction evaluation value level higher than a noise level is valid as a condition for direction determination. Since the amplification amount of the noise component changes depending on the amplification factor of AGC, the driving direction evaluation value level to be neglected is also changed in accordance with the amplification factor, thereby preventing an erroneous AF operation.
Third, program mode information is used. When the program mode is changed during the hill-climbing operation (steps S 605 and S 606 ) or reactivation determination (steps S 610 , S 611 , and S 612 ) shown in FIG. 6, the exposure state also changes, and the AF evaluation value also changes accordingly, resulting in an erroneous operation.
As a means for solving this problem, when the program mode is changed, the flow returns to step S 602 in the flow chart of FIG. 6 . Processing from the wobbling operation is started again, thereby preventing driving in an erroneous direction for generating a blur.
FIG. 9 shows the improved part of the algorithm shown in the flow chart of FIG. 6. A detailed description thereof will be omitted. Steps S 1001 , S 1002 , S 1003 , and S 1004 are added to steps S 605 and S 610 in FIG. 6 . If a change in program mode is detected (step S 1001 ), processing waits for stabilization of the exposure state (steps S 1002 and S 1003 ). Thereafter, processing from the wobbling operation (step S 602 ) is started again.
In this series of processing, a wait time counter C in step S 1002 does not exceed a predetermined value CO of the wait time because the RAM (not shown) in the lens microcomputer 116 is cleared by the initialization operation of the lens microcomputer 116 .
Fourth, read period information for slow shutter control is used. In slow shutter control, the AF evaluation value cannot be obtained every 1V sync period. For example, when the slow shutter speed is {fraction (1/15)}, the AF evaluation value is obtained only every 4V sync period. If AF control as shown in FIG. 6 is performed assuming that the AF evaluation value is updated every V, an in-focus state is erroneously determined because no difference is present between the evaluation value levels as wobbling results even in an out-of-focus state. For this reason, the AF operation is completed in the out-of-focus state.
To prevent such an erroneous operation, assume that, in slow shutter control, the AF evaluation value is updated only at the read period. Mountain shape determination or the reactivation operation during the wobbling or hill-climbing operation is performed in synchronism with the read period, thereby preventing an erroneous operation.
Fifth, image enlargement magnification information of electronic zooming is used. This will be described with reference to FIGS. 3A and 3B. Referring to FIGS. 3A and 3B, reference numeral 301 denotes a sensing frame; 302 , a distance measurement area (distance measurement frame) for extracting an AF evaluation value which has been already described above.
Assume that an object 304 at a closer position and a distant object 305 are present in the sensing frame. In this embodiment, the AF evaluation value is defined as the peak value of a high-frequency component of a video signal in the distance measurement frame. Therefore, when the rear object 305 has a luminance higher than that of the object 304 , AF control is performed to make the lens focus on the object 305 .
Assume that the area 302 is enlarged by electronic zooming or the like, as shown in FIG. 3 B. At this time, the photographer looks at the screen of the monitor indicated by reference numeral 306 in which the object 304 is enlarged, as shown in FIG. 3B (FIG. 3B shows display on the monitor, though FIG. 3A shows the picture frame to be sensed by the image sensing device).
If the AF distance measurement frame is kept in the size indicated by reference numeral 302 , the lens may be focused on the object 305 which is not displayed on the monitor. In this case, the image on the monitor at which the photographer looks is kept blurred.
To eliminate this disadvantage, the size of the distance measurement frame is changed in accordance with the enlargement magnification information of electronic zooming. In this case, the distance measurement frame in electronic zooming is set as indicated by reference numeral, e.g., 303 .
When the size of the distance measurement frame is changed in accordance with the image magnification information, AF control can be realized while preventing the focus state from shifting from the main object intended by the photographer.
In electronic zooming, since the object is enlarged, the AF evaluation value largely changes due to a change in object, the camera operation, or a camera shake. To stabilize the AF performance, the distance measurement frame is preferably set to be as large as possible (in this embodiment, the distance measurement frame is set to equal the enlarged frame size).
When an object is enlarged, even a blur within the depth of field sometimes becomes visible. It is preferable therefore to set the fine driving amount a of the focus lens in a wobbling operation or the like to be smaller than that in a normal mode.
Changing the size of the distance measurement frame in accordance with the selected program mode is useful for sensing reflecting the intention of the photographer. For example, a portrait mode aims at an effect of vignetting the background. The main object is present at the center of the picture frame and in a bust-up state to some extent. Therefore, it is preferable that only the central portion of the picture frame be set as a distance measurement frame smaller than that in a normal mode.
In a landscape mode for sensing a landscape, the upper portion of the picture frame is mainly occupied by the sky. The target object is often present on the lower side of the picture frame, so the focus point sometimes shifts due to the movement of the object. Therefore, a relatively large distance measurement frame is preferably set mainly on the lower side of the picture frame to prevent the object from leaving the distance measurement frame and entering into it because of a camera shake.
Typical examples of sensing state information which is transferred from the camera main body to the lens assembly have been described above. However, the present invention is not limited to the above examples. Any information can be transferred to the lens assembly as long as the information represents a sensing state such as a camera signal processing state, i.e., gamma correction or an aperture state.
An example in which the AF evaluation value is transferred from the camera main body to the lens assembly has been described above. The present invention can be applied to a system having a lens control means for focusing in the lens assembly. Instead of the AF evaluation value, a video signal itself may be transferred, and the AF evaluation value may be generated in the lens assembly having the AF signal processing circuit 113 .
Second Embodiment
The second embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, AF control processing of adjusting a shift between an actual lens position and locus data as a design value stored in advance will be described. In addition, the operation of an AF signal processing circuit will be described in more detail than in the first embodiment. FIG. 10 is a block diagram showing the arrangement of an interchangeable lens video camera system according to the second embodiment of the present invention.
Referring to FIG. 10, a lens assembly 1127 is detachably attached to a camera main body 1128 to constitute a so-called interchangeable lens system.
Light from an object form images on the image sensing surfaces of image sensing devices 1106 to 1108 , e.g., CCDs, in the camera main body through a fixed first lens group 1101 , a second lens group 1102 (to be referred to as a variable power lens hereinafter) for performing a zooming operation, an iris stop 1103 , a fixed third lens group 1104 , and a fourth lens group 1105 (to be referred to as a focus lens hereinafter) in the lens assembly 1127 . The fourth lens 1105 has both a focusing function and a function of compensating for the movement of a focal plane caused by zooming.
The image sensing devices in the camera main body 1128 are provided for three primary colors, red (R), green (G), and blue (B), respectively, constituting a so-called three-sensor image sensing system.
Images of the three primary colors, red, green, and blue, are formed on the image sensing devices 1106 , 1107 , and 1108 , respectively.
The images formed on the image sensing devices 1106 , 1107 , and 1108 are photoelectrically converted and amplified to their respective optimum levels by amplifiers 1109 , 1110 , and 1111 , respectively. These images are then input to a camera signal processing circuit 1112 and converted into a standard TV signal. This signal is output to, e.g., a video recorder (not shown) and also input to an AF signal processing circuit 1113 .
A focus evaluation value (AF evaluation value) is generated by the AF signal processing circuit 1113 in accordance with the focus state and is read out at a period which is an integral multiple of a vertical sync signal by a data read program 1115 of a microcomputer 1114 in the camera main body 1128 . The readout AF evaluation value is transferred to a lens microcomputer 1116 on the lens assembly 1127 side.
In the camera signal processing circuit 1112 , the levels of luminance signals of the output image sensing signals from the image sensing devices are detected and transferred to the lens microcomputer 1116 in the lens assembly 1127 through the microcomputer 1114 . On the basis of this luminance signal information, an iris driver 1124 is controlled, an IG meter 1123 is driven, and the iris stop 1103 is controlled.
The aperture value of the iris stop 1103 is detected by an encoder 1129 , supplied to the lens microcomputer 1116 , and used as depth-of-field information.
The microcomputer 1114 of the camera main body 1128 reads out the states of a zoom switch 1130 and an AF switch (when ON, an AF operation is performed; when OFF, a manual focus mode is set) 1131 and transmits the readout states of the switches to the lens microcomputer 1116 . With this operation, a motor driver 1122 is controlled in accordance with the operation state of the zoom switch 1130 to drive a zoom motor 1121 and drive the zoom lens 1102 in the direction operated by the zoom switch, thereby performing a zooming operation.
In the lens microcomputer 1116 , an AF program 1117 is operated, and the state of the AF switch 1131 and the AF evaluation value from the microcomputer 1114 are received. When the AF switch 1131 is ON, a motor control program 1118 is operated on the basis of the AF evaluation value to drive a focus motor 1125 through a focus motor driver 1126 and move the focus lens 1105 along the optical axis, thereby performing focusing.
An adjustment start switch 1135 is arranged on the camera main body 1128 side to start an adjustment operation on the lens assembly 1127 side to adjust the locus of lens cam data stored in advance and an actual lens driving locus. The operation state of this switch is also transmitted to the lens assembly 1127 side through the microcomputer 1114 . When the adjustment switch 1135 is ON, an adjustment program 1132 corresponding to an adjusting means in the lens microcomputer 1116 (to be described later) is operated to drive the lens group with reference to the AF evaluation value. With this operation, adjustment for the actual lens optical system and lens cam data 1120 as a memory means is performed.
An operation which changes depending on the states of the adjustment switch 1135 , the AF switch 1131 , and the zoom switch 1130 will be described below.
The adjustment switch 1135 may be arbitrarily manually turned on/off. However, when the adjustment switch 1135 is automatically turned on in a manner interlocked with an operation of mounting the lens assembly in the camera main body, adjustment can be automatically performed every time the lens unit attached to the camera main body is exchanged, resulting in an improvement in operability. In addition, an adjustment operation can be executed while the operator is not conscious of it. Therefore, the lens assembly can always be controlled with optimum characteristics.
The adjustment switch 1135 may be mechanically controlled upon coupling a mount, or controlled using software such as initial communication between the lens microcomputer and the main body microcomputer of the camera main body.
When the adjustment switch 1135 is OFF, a normal sensing operation as will be described below is executed on the basis of the states of the AF switch 1131 and the zoom switch 1130 .
When the AF switch 1131 is OFF (manual focus mode) and the zoom switch 1130 is depressed, a computer zoom program 1119 serving as a zooming control means is operated. In accordance with the information of the zoom direction operated by the zoom switch 1130 and the position information obtained by detecting the positions of the zoom lens and the focus lens from the respective motor driving amounts or by using an encoder, the computer zoom program 1119 specifies the in-focus locus along which the focus lens is to trace during a zooming operation and the trace direction. The computer zoom program 1119 reads out the specified locus and trace direction from the lens cam data 1120 and calculates the compensating speed and direction of the focus lens corresponding to the zooming operation.
The calculation result is sent as a signal to the zoom motor driver 1122 to drive the variable power lens 1102 through the zoom motor 1121 . The signal is also sent to the focus motor driver 1126 to drive the focus lens 1105 through the focus motor 1125 , thereby performing a zooming operation. As the lens cam data 1120 , locus data obtained by storing an in-focus can locus representing a change in in-focus position of the focus lens with respect to a change in position of the variable power lens, as shown in FIG. 26, for each object distance is stored in the ROM (not shown) in the lens microcomputer 1116 . With the operation of the computer zoom program 1119 , a lens cam locus to be traced by the focus lens is read out from the lens cam data 1120 in the zooming operation, thereby driving and controlling the focus lens.
When the AF switch 1131 is ON, and the zoom switch 1130 is depressed, it is necessary to hold the in-focus state even if the object moves. Accordingly, the computer zoom program 1119 operates to not only perform control on the basis of the lens cam data 1120 stored in the lens microcomputer 1116 as described above but also simultaneously refer to the AF evaluation value signal sent from the main body microcomputer 1114 on the camera side, thereby performing a zooming operation while holding the position at which the AF evaluation value is maximized.
That is, the driving speed and direction of the focus lens 1105 are calculated by adding the information of the compensating speed and direction of the focus lens obtained by the computer zoom program 1119 in accordance with the zooming operation to the information of the driving speed and direction of the focus lens based on the out-of-focus information output with the operation of the AF program 1117 . The driving speed and direction thus calculated are supplied to the focus motor driver 1126 .
When the AF switch 1131 is ON, and the zoom switch 1130 is not depressed, the AF program 1117 in the lens microcomputer 1116 receives the AF evaluation value transmitted from the microcomputer 1114 . On the basis of this AF evaluation value, the motor control program 1118 is operated. The focus motor 1125 is driven by the focus motor driver 1126 , and a signal is sent to the focus motor driver 1126 to drive the focus lens 1105 through the focus motor 1125 such that the AF evaluation value is maximized, thereby performing an automatic focusing operation.
The aperture value of the iris stop 1103 is detected by the encoder 1129 , supplied to the lens microcomputer 1116 , and used as the depth-of-field information to compensate for, e.g., the speed of the focus lens.
The AF signal processing circuit 1113 in the camera signal processing circuit 1112 will be described below with reference to FIG. 11 . The image sensing device outputs of red (R), green (G), and blue (B) are amplified to their respective optimum levels by the amplifiers 1109 , 1110 , and 1111 and supplied to the AF signal processing circuit 1113 . The output signals are converted into digital signals by A/D converters 1206 , 1207 , and 1208 and supplied to the camera signal processing circuit 1112 . At the same time, these digital signals are amplified to their respective optimum levels by amplifiers 1209 , 1210 , and 1211 and added by an adder 1208 , generating an automatic focusing luminance signal S 15 .
The luminance signal S 15 is input to a gamma circuit 1213 and gamma-converted in accordance with a preset gamma curve, forming a signal S 16 whose low-luminance component is increased and high-luminance component is decreased. The gamma-converted signal S 16 is applied to a low-pass filter (to be referred to as an LPF hereinafter) with a high cut-off frequency, i.e., a TE-LPF 1214 , and to an FE-LPF 1215 which is an LPF with a low cut-off frequency. The TE-LPF 1214 and the FE-LPF 1215 extract low-frequency components on the basis of the respective filter characteristics determined by the main body microcomputer 1114 via a microcomputer interface 1253 . Consequently, the TE-LPF 1214 generates an output signal S 17 , and the FE-LPF 1215 generates an output signal S 18 .
A line E/O signal is generated by the microcomputer 1114 to identify whether the horizontal line is an even-numbered line or an odd-numbered line. On the basis of this signal, the signals S 17 and S 18 are selectively switched by a switch 1216 and applied to a high-pass filter (to be referred to as an HPF hereinafter) 1217 .
That is, the signal S 17 is supplied to the HPF 1217 when the horizontal line is an even-numbered line, and the signal S 18 is supplied to the HPF 1217 when the horizontal line is an odd-numbered line.
The HPF 1217 extracts only a high-frequency component in accordance with filter characteristics determined for even- and odd-numbered lines by the main body microcomputer 1114 via the microcomputer interface 1253 . An absolute value circuit 1218 obtains an absolute value of the extracted signal to generate a positive signal S 19 . That is, the signal S 19 alternately indicates the levels of high-frequency components extracted by the filter having different filter characteristics for even- and odd-numbered lines. Consequently, different frequency components can be obtained by scanning one picture frame.
In accordance with an instruction supplied by the microcomputer 1114 via the microcomputer interface 1253 , a frame generating circuit 1254 generates gate signals L, C, and R for forming focus control gate frames L, C, and R, respectively, at positions in the image sensing surface as shown in FIG. 12 . Timings at which various kinds of information are fetched in the AF signal processing circuit 1113 will be described below with reference to FIG. 12 which shows the layout of focus detection areas in the image sensing surface.
FIG. 12 is a view for explaining the operations and timings of extraction of various focus evaluation values in the second embodiment of the present invention. Referring to FIG. 12, the outside frame is an effective image sensing surface of the outputs from the image sensing devices 1106 , 1107 , and 1108 .
Three divided inside frames are focus detection gate frames. The left frame L, the central frame C, and the right frame R are formed in accordance with the frame L generating gate signal, the frame C generating gate signal, and the frame R generating gate signal, respectively, from the frame generating circuit 1254 .
At the start positions of these frames L, C, and R, reset signals are output for the frames L, C, and R to generate initialization (reset) signals LR 1 , CR 1 , and RR 1 , respectively, thereby resetting integrating circuits 1232 to 1237 and peak hold circuits 1219 to 1221 , 1225 to 1227 , and 1247 to 1249 .
Also, when the focus detection area consisting of the frames L, C, and R is completely scanned, a data transfer signal IR 1 is generated to transfer the integral values of the integrating circuits and the peak hold values of the peak hold circuits to their respective buffers.
Referring to FIG. 12, the scan of an even-numbered field is indicated by solid lines, and the scan of an odd-numbered field is indicated by dotted lines. In both the even- and odd-numbered fields, the TE-LPF output is selected on an even-numbered line, and the FE-LPF output is selected on an odd-numbered line.
An automatic focusing operation performed by the microcomputer by using a TE/FE peak evaluation value, a TE line peak integral evaluation value, an FE line peak integral evaluation value, a Y signal peak evaluation value, and a Max-Min evaluation value in each frame will be described below. Note that these evaluation values are transmitted to the microcomputer 1116 in the lens assembly and the microcomputer 1116 performs actual control.
The signal S 19 is supplied to the peak hold circuits 1225 , 1226 , and 1227 for detecting signal peak values in the left, central, and right frames (to be referred to as frames L, C, and R hereinafter) in the image sensing surface. These peak hold circuits detect the peak values of high-frequency components in their respective frames. The signal S 19 is also supplied to a line peak hold circuit 1231 to detect the peak value of each horizontal line.
The peak hold circuit 1225 receives the output gate signal L for forming the frame L from the frame generating circuit 1254 , the signal S 19 , and the Line E/O signal. As shown in FIG. 12, the peak hold circuit 1225 is initialized in the upper left corner, i.e., LR 1 , which is the start position of the focusing frame L. The peak hold circuit 1225 holds a peak value of the signal S 19 in the frame L of either an even- or odd-numbered line designated by the microcomputer 1114 via the microcomputer interface 1253 . In the lower right corner IR 1 , i.e., when the entire focusing area is completely scanned, the peak hold value in the frame L is transferred to an area buffer 1228 to generate a TE/FE peak evaluation value.
Likewise, the peak hold circuit 1226 receives the output frame C signal from the frame generating circuit 1254 , the Line E/O signal, and the signal S 19 . As in FIG. 12, the peak hold circuit 1226 is initialized in the upper left corner, i.e., CR 1 , which is the start position of the focusing frame C. The peak hold circuit 1226 holds a peak value of the signal S 19 in the frame C of either an even- or odd-numbered line designated by the microcomputer 1114 via the microcomputer interface 1253 . In IR 1 , i.e., when the overall focusing area is completely scanned, the peak hold value in the frame C is transferred to an area buffer 1229 to generate a TE/FE peak evaluation value.
Similarly, the peak hold circuit 1227 receives the output frame R signal from the frame generating circuit 1254 , the Line E/O signal, and the signal S 19 . As in FIG. 12, the peak hold circuit 1227 is initialized in the upper left corner, i.e., RR 1 , which is the start position of the focusing frame R. The peak hold circuit 1227 holds a peak value of the signal S 19 in the frame R of either an even- or odd-numbered line designated by the microcomputer 1114 via the microcomputer interface 1253 . In IR 1 , i.e., when the overall focusing area is completely scanned, the peak hold value in the frame R is transferred to a buffer 1230 to generate a TE/FE peak evaluation value.
The line peak hold circuit 1231 receives the signal S 19 and the output gate signals for generating the frames L, C, and R from the frame generating circuit 1254 . The line peak hold circuit 1231 is initialized at the start point in the horizontal direction of each frame and holds a peak value of each line in the horizontal line of the signal S 19 in each frame.
The integrating circuits 1232 , 1233 , 1234 , 1235 , 1236 , and 1237 receive the output from the line peak hold circuit 1231 and the Line E/O signal which identifies whether the horizontal line is an even- or odd-numbered line. The integrating circuits 1232 and 1235 receive the frame L generating gate signal supplied from the frame generating circuit 1254 . The integrating circuits 1233 and 1236 receive the frame C generating gate signal supplied from the frame generating circuit 1254 . The integrating circuits 1234 and 1237 receive the frame R generating gate signal supplied from the frame generating circuit 1254 .
The integrating circuit 1232 is initialized in the upper left corner, i.e., LR 1 , which is the start position of the focusing frame L. The integrating circuit 1232 adds the output from the line peak hold circuit 1231 to an internal register immediately before the end of an even-numbered line in each frame. In IR 1 , the integrating circuit 1232 transfers the peak hold value to an area buffer 1238 to generate a TE line peak integral evaluation value.
The integrating circuit 1233 is initialized in the upper left corner, i.e., CR 1 , which is the start position of the focusing frame C. The integrating circuit 1233 adds the output from the line peak hold circuit 1231 to an internal register immediately before the end of an even-numbered line in each frame. In IR 1 , the integrating circuit 1233 transfers the peak hold value to a buffer 1239 to generate a TE line peak integral evaluation value.
The integrating circuit 1234 is initialized in the upper left corner, i.e., RR 1 , which is the start position of the focusing frame R. The integrating circuit 1234 adds the output from the line peak hold circuit 1231 to an internal register immediately before the end of an even-numbered line in each frame. In IR 1 , the integrating circuit 1234 transfers the peak hold value to an area buffer 1240 to generate a TE line peak integral evaluation value.
The integrating circuits 1235 , 1236 , and 1237 perform the same operations as the integrating circuits 1232 , 1233 , and 1234 , respectively, except that the integrating circuits 1235 , 1236 , and 1237 perform addition of odd-numbered line data, instead of performing addition of even-numbered line data such as done by the integrating circuits 1232 , 1233 , and 1234 . The integrating circuits 1235 , 1236 , and 1237 transfer the results to area buffers 1241 , 1242 , and 1243 , respectively, generating FE line peak integral evaluation values.
The signal S 17 is input to the peak hold circuits 1219 , 1220 , and 1221 , a line maximum value hold circuit 1244 , and a line minimum value hold circuit 1245 .
The peak hold circuit 1219 receives the frame L generating gate signal supplied from the frame generating circuit 1254 . The peak hold circuit 1219 is initialized in the upper left corner, i.e., LR 1 , which is the start position of the frame L, and holds a peak value of the signal S 17 in each frame. In IR 1 , the peak hold circuit 1219 transfers the peak hold result to the buffer 1222 to generate a peak evaluation value of a luminance level (to be referred to as a Y signal hereinafter).
Analogously, the peak hold circuit 1220 receives the frame C generating gate signal supplied from the frame generating circuit 1254 . The peak hold circuit 1220 is initialized in the upper left corner, i.e., CR 1 , which is the start position of the frame C, and holds a peak value of the signal S 17 in each frame. In IR 1 , the peak hold circuit 1220 transfers the peak hold result to the buffer 1223 to generate a Y signal peak evaluation value.
Likewise, the peak hold circuit 1221 receives the frame R generating gate signal from the frame generating circuit 1254 . The peak hold circuit 1221 is initialized in the upper left corner, i.e., RR 1 , which is the start position of the frame R, and holds the peak value of the signal S 17 in each frame. In IR 1 , the peak hold circuit 1221 transfers the peak hold result to the buffer 1224 to generate a Y signal peak evaluation value.
The line maximum value hold circuit 1244 and the line minimum value hold circuit 1245 receive the frame L, C, and R generating gate signals supplied from the frame generating circuit 1254 . The line maximum value hold circuit 1244 and the line minimum value hold circuit 1245 are initialized at the start point in the horizontal direction in each frame and hold the maximum value and the minimum value, respectively, of the Y signal on one horizontal line of the signal S 17 in each frame.
The maximum and the minimum values of the Y signal held by the line maximum value hold circuit 1244 and the line minimum value hold circuit 1245 are input to a subtracter 1246 . The subtracter 1246 calculates a (maximum value-minimum value) signal, i.e., a signal S 20 which indicates the contrast, and inputs the signal to the peak hold circuits 1247 , 1248 , and 1249 .
The peak hold circuit 1247 is applied with the frame L generating gate signal from the frame generating circuit 1254 . The peak hold circuit 1247 is initialized in the upper left corner, i.e., LR 1 , which is the start position of the frame L, and holds a peak value of the signal S 20 in each frame. In IR 1 ., the peak hold circuit 1247 transfers the peak hold result to a buffer 1250 to generate a Max-Min evaluation value.
Similarly, the peak hold circuit 1248 receives the frame C generating gate signal from the frame generating circuit 1254 . The peak hold circuit 1248 is initialized in the upper left corner, i.e., CR 1 , which is the start position of the frame C, and holds a peak value of the signal S 20 in each frame. In IR 1 , the peak hold circuit 1248 transfers the peak hold result to a buffer 1251 to generate a Max-Min evaluation value.
Analogously, the peak hold circuit 1249 is applied with the frame R generating gate signal from the frame generating circuit 1254 . The peak hold circuit 1249 is initialized in the upper left corner, i.e., RR 1 , which is the start position of the frame R, and holds a peak value of the signal S 20 in each frame. In IR 1 , the peak hold circuit 1249 transfers the peak hold result to a buffer 1252 to generate a Max-Min evaluation value.
In IR 1 , i.e., when the entire focusing area consisting of the frames L, C, and R is completely scanned, the data in these frames are transferred to the buffers 1222 , 1223 , 1224 , 1228 , 1229 , 1230 , 1238 , 1239 , 1240 , 1241 , 1242 , 1243 , 1250 , 1251 , and 1252 . Simultaneously, the frame generating circuit 1254 sends an interrupt signal to the microcomputer 1114 and transfers the data, which are transferred to these buffers, to the microcomputer 1114 .
That is, upon receiving the interrupt signal, the microcomputer 1114 reads out the data (focus evaluation values) from the buffers 1222 , 1223 , 1224 , 1228 , 1229 , 1230 , 1238 , 1239 , 1240 , 1241 , 1242 , 1243 , 1250 , 1251 , and 1252 via the microcomputer interface 1253 before the succeeding scan of the frames L, C, and R is completed and the data are transferred to these buffers. As will be described later, the microcomputer 1114 transfers the data to the microcomputer 1116 in synchronism with a vertical sync signal.
The microcomputer 1116 of the lens assembly 1127 detects the focus state by performing calculations by using these transferred focus evaluation values. The microcomputer 1116 then calculates, e.g., the driving speed and the driving direction of the focus motor 1125 and controls driving of the focus motor 1125 , thereby driving the focusing lens 1105 .
The characteristics and applications of the above evaluation values will be described below.
The TE/FE peak evaluation value represents an in-focus degree and is a peak hold value. Therefore, this evaluation value is less influenced by a camera shake and comparatively less depends upon the state of an object. For these reasons, this evaluation value is optimum for in-focus degree determination and reactivation determination.
The TE line peak integral evaluation value and the FE line peak integral evaluation value also represent an in-focus degree. However, these evaluation values are optimum for direction determination since they have little noise and are stable as a result of integration.
Of the above peak evaluation values and line peak integral evaluation values, each TE evaluation value is formed by extracting higher frequencies and hence is optimum as an evaluation value near the in-focus point. In contrast, each FE evaluation value is optimum when an image is largely blurred in a position very far from the in-focus point. Accordingly, by adding these signals or selectively switching the signals in accordance with the TE level, it is possible to perform AF over a wide dynamic range from the state in which an image is largely blurred to the vicinity of the in-focus point.
The Y signal peak evaluation value and the Max-Min evaluation value do not depend much upon the in-focus degree but upon the state of an object. Therefore, these evaluation values are optimum to check the change or movement of an object in order to reliably perform in-focus degree determination, reactivation determination, and direction determination. These values are also used in normalization for removing the influence of a change in brightness.
More specifically, the Y signal peak evaluation value is used to check whether the object is a high-luminance object or a low-luminance object. The Max-Min evaluation value is used to check whether the contrast is high or low. Furthermore, optimum AF control can be performed by predicting and compensating for the peak values, i.e., the magnitudes of peaks, on the characteristic curves of the TE/FE peak evaluation value, the TE line peak integral evaluation value, and the FE line peak integral evaluation value.
These evaluation values are transferred from the camera main body 1128 to the lens assembly 1127 and supplied to the lens microcomputer 1116 of the lens assembly 1127 , and the automatic focusing operation is performed.
The algorithm of an automatic focusing operation performed by the lens microcomputer 1116 of the lens assembly 1127 will be described below with reference to FIG. 13 .
When the processing is started, the microcomputer 1116 activates the AF operation in step S 1301 , and the flow advances to step S 1302 . In step S 1302 , the microcomputer 1116 checks the distance from the in-focus point by comparing the level of the TE or FE peak with a predetermined threshold, and performs speed control.
If the TE level is low, i.e., if the current focus point is far from the in-focus point and therefore the image is predicted to be largely blurred, the microcomputer 1116 performs hill-climbing control for the focus lens by controlling the direction of the lens by primarily using the FE line peak integral evaluation value. When the TE level rises to a certain degree near the peak of the characteristic curve, the microcomputer 1116 performs hill-climbing control for the focus lens by using the TE line peak integral evaluation value. In this way, the microcomputer 1116 so performs control that the in-focus point can be accurately detected.
If the lens comes close to the in-focus point, the flow advances to step S 1303 , and the microcomputer 1116 determines the peak of the characteristic curve by using the absolute value of the TE or FE peak evaluation value or a change in the TE line peak integral evaluation value. If the microcomputer 1116 determines that the level of the evaluation value is highest at the peak, i.e., the in-focus point, the microcomputer 1116 stops the focus lens in step S 1304 and advances to reactivation waiting in step S 1305 .
In reactivation waiting, if the microcomputer 1116 detects that the level of the TE or FE peak evaluation value decreases by a predetermined level or more from the peak value obtained when the in-focus point is detected, the microcomputer 1116 reactivates the operation in step S 1306 .
In the loop of the automatic focusing operation as described above, the speed of the focus lens is controlled by using the TE/FE peak. The level of the absolute value for determining the peak of the characteristic curve and the change in the TE line peak integral evaluation value are determined by predicting the height of the hill by checking the object by using the Y peak evaluation value or the Max-Min evaluation value. The AF operation can always be performed by repeating the above processing.
An in-focus state adjustment operation performed when the adjustment switch 1135 is ON will be described below.
FIG. 14 shows the algorithm of an adjustment operation performed by the adjustment program 1132 in the lens microcomputer 1116 when focusing as a characteristic feature of the present invention is performed.
Processing is started in step S 1401 . In step S 1402 , the position of the variable power lens on the optical axis is set at a zoom position (position {circle around (1)} in FIG. 27) corresponding to the vicinity of the peak of the locus of the focus lens.
In step S 1403 , the focus lens 1105 is moved by the focus motor to perform focusing.
The object distance is set as an adjustment distance (∞). An object, e.g., a chart is arranged for adjustment, and the adjustment distance is set.
In step S 1404 , it is checked whether the lens is at an in-focus position. The focus lens 1105 is moved until an in-focus state is set.
In actual focusing, the AF program 1117 shown in FIG. 27 is operated to detect the focus lens position at which the AF evaluation value is maximized, thereby detecting the in-focus position.
If it is confirmed in step S 1404 that the lens is at the in-focus position, the focus lens is lowered by A on the basis of the design value of this lens in step S 1405 (“lower” means that the lens is moved to the lower side of FIG. 27 : in fact, the zoom lens is extended to the object side or retracted to the image plane side depending on its zoom type).
In step S 1406 , the variable power lens in this state is driven to a telephoto side T. It is determined in step S 1407 whether an in-focus state is set.
When movement of the variable power lens is completed, and an in-focus state is detected at that position, the position of the variable power lens corresponds to the variable power lens position at the telephoto end.
In step S 1408 , the position of the zoom encoder in that state is stored in Vta as a value for defining the position of the telephoto end.
In step S 1409 , the focus lens is moved along the optical axis by a balance amount corresponding to the difference between the in-focus position of the focus lens at the telephoto end and that at the wide end within the adjustment distance.
However, if this balance is zero, as in FIG. 27, the focus lens need not be moved. Subsequently, in steps S 1410 and S 1411 , the variable power lens is moved as in determination of the telephoto end, thereby determining the reference position of the variable power lens on the wide side.
In step S 1412 , the position of the zoom encoder, which corresponds to the position of the variable power lens, is stored in Vwa as the position of the variable power lens with a focus reference value. In step S 1413 , this in-focus position is set as the reference position of the focus lens. In step S 1414 , the adjustment operation is ended.
As described above, Vwa, Vta, and the focus lens reference position, which are obtained with the adjustment operation in FIG. 14 ,.respectively correspond to the wide end v=0, the telephoto end v=s, and in-focus position data A 00 in the direction of infinity of the wide end (=A 0 s: in this embodiment, the balance difference between the wide end and the telephoto end is zero), as shown in FIG. 31 .
By matching the coordinate axes of the actual lens position with those of the locus table data as design data stored in advance, zooming free from a blur is realized. In addition, when the lens assembly 1127 incorporates the program shown in FIG. 14, an interchangeable lens system to which not only a front focus type lens but also lenses of various types including an inner focus type lens assembly are connectable can be realized.
Third Embodiment
The third embodiment will be described below.
FIG. 15 is a block diagram showing the arrangement of the third embodiment of the present invention. The basic arrangement is the same as that in the second embodiment. Hence, a detailed description thereof will be omitted (the same reference numerals as in the second embodiment denote the same elements in the third embodiment), and only different portions will be described below. In this embodiment, a camera main body 1127 transfers not an AF evaluation value but a video signal to a lens assembly 1127 . On the basis of an AF evaluation value generated in the lens assembly 1127 , a lens focusing or AF/zooming operation is realized.
Object images formed on image sensing devices 1106 , 1107 , and 1108 are photoelectrically converted and amplified to their respective optimum levels by amplifiers 1209 , 1210 , and 1211 , input to a camera signal processing circuit 1112 , and converted into a standard TV signal. At the same time, a video signal S 13 obtained by mixing R, G, and B signals without gamma conversion is output and input to a video signal normalizing circuit 1601 .
When all cameras take the same object, the video signal normalizing circuit 1601 normalizes the video signal to have the same level, so that a normalized video signal S 14 is output.
The normalized video signal S 14 is sent from the camera main body 1128 to the lens assembly 1127 through a lens mount. The lens assembly 1127 inputs the normalized video signal S 14 from the camera main body 1128 to an AF signal processing circuit 1602 .
An AF evaluation value generated by the AF signal processing circuit 1602 is read out with the operation of a data read program 1603 in a lens microcomputer 1116 B.
A main body microcomputer 1114 B reads out the states of a zoom switch 1130 , an AF switch 1131 , and an adjustment start switch 1135 and sends the states of the switches to the lens microcomputer 1116 B, thereby performing the same control as in the above-described second embodiment.
The AF signal processing circuit 1602 has an arrangement shown in FIG. 16 . The normalized video signal S 14 received from the camera main body 1128 is converted into a digital signal by an A/D converter 1701 to generate an automatic focusing luminance signal S 15 .
The signal S 15 is input to a gamma circuit 1213 and subjected to the same processing as in the second embodiment, which has been described with reference to FIG. 11, to generate an AF evaluation value.
In this embodiment, the normalized video signal S 14 is an analog signal which is converted into a digital video signal by an AF signal processing circuit 1113 . However, the digital signal output from the camera signal processing circuit 1112 may be normalized and, without conversion, transferred from the camera main body 1128 to the lens assembly 1127 . If adjustment of an in-focus state is unnecessary, processing by the adjustment start switch 1135 of the camera main body 1128 and associated processing by a microcomputer 1605 may be omitted. In addition, the adjustment program for the lens assembly 1127 may be omitted to realize a system configuration shown in FIG. 17 . In this case, the AF signal processing circuit has an arrangement shown in FIG. 16, as a matter of course.
Fourth Embodiment
The fourth embodiment of the present invention will be described below.
FIG. 18 is a block diagram of an interchangeable lens video camera system according to the fourth embodiment of the present invention. The basic arrangement is the same as that in the second embodiment except that the adjustment start switch 1135 and the adjustment program 1132 shown in FIG. 10 are omitted. Hence, a detailed description thereof will be omitted (the same reference numeral as in the second embodiment denote the same elements in the fourth embodiment), and only different portions will be described below.
In this embodiment, a lens microcomputer 1116 D in a lens assembly 1127 has a lens data memory unit 1133 which is backed up by a memory holding power supply 1135 . An application of a lens locus stored in the lens data memory unit 1133 will be described below.
Assume that the power supply of the system with the arrangement in FIG. 18 is turned off, and the system is repowered. At this time, to trace an in-focus locus which has been previously traced, representative locus data traced by a focus lens, the internal ratio, the position of a focus lens 1105 , and the position of a variable power lens 1102 before turning off the power supply must be kept stored in the lens microcomputer 1116 D or reproduced.
An algorithm for reproducing data at the time of turning on the power supply will be described below with reference to FIG. 19 .
When the power supply is turned on in step S 1901 , the lens microcomputer 1116 D refers to the backed-up memory in the lens microcomputer to determine whether the lens unit is detached/attached from/to the camera main body.
If it is determined in step S 1902 from the state before turning off the power supply that the lens unit has been exchanged, the flow advances to step S 1903 to confirm whether lens data is stored in the lens data memory unit 1133 in the lens microcomputer 1116 D.
This confirmation is also made to determine whether the memory holding power supply 1135 of the lens data memory unit 1133 in the lens microcomputer 1116 D has been normally operated after the power-OFF.
If NO in step S 1903 , the flow advances to step S 1905 . If YES in step S 1903 , the flow advances to step S 1904 , and locus data including the position data of the focus lens and the variable power lens, the representative locus to be used, and the internal ratio is read out from the lens data memory unit 1133 into a focus control program 1117 and a computer zoom program 1119 of the lens microcomputer 1116 D. On the basis of these backup data, the positions of the focus lens and the variable power lens and the locus to be traced are determined. The positions of the focus lens and the variable power lens and the control state are returned to those before the power supply is turned off, and the flow advances to step S 1906 .
If NO in step S 1902 , or if NO in step S 1903 , the lens positions and locus are initialized in the lens assembly in step S 1905 to set the focus lens and the variable power lens to their initial positions, and the flow advances to step S 1906 .
When the power-ON sequence is completed, and a normal operation is started, in step S 1906 , the current lens positions and locus in the lens microcomputer 1116 D are written in the lens data memory unit 1133 at a predetermined period (e.g., a period which is an integral multiple of the vertical sync signal of a video signal) such that the data can be stored even when the power supply is turned off.
With this arrangement, when a detaching or exchange operation of the lens assembly is performed before or after the power supply is turned off, the initialization operation for the focus lens and the variable power lens is performed upon repowering. If the detaching or exchange operation of the lens assembly is not performed before or after the power supply is turned off, the state before the power supply is turned off is read out from the lens data memory unit, so that the state before the power supply is turned off can be restored.
Even when the power supply is turned off, the state before turning off the power supply can be reproduced at the time of repowering. The state is not reset every time the power supply is turned on/off, so that the sensing state before the power supply is turned off can be continued.
FIG. 20 is a flow chart showing the first modification of the fourth embodiment of the present invention.
In the fourth embodiment shown in FIG. 19, when the lens assembly is detached/attached before or after the power supply is turned off, initialization is performed. When the lens assembly is not detached/attached, the state before the power supply is turned off is reproduced on the basis of the data stored in the lens data memory unit. In this modification, identification information for the camera main body connected before the power supply is turned off is stored. If the lens assembly is connected to the same camera main body at the time of repowering, the initialization operation is not performed. The state before the power supply is turned off is reset on the basis of the data stored in the lens data memory unit. If another lens assembly is connected, the initialization operation is performed.
As shown in FIG. 18, the arrangement of this modification is the same as that in the fourth embodiment of the present invention, and a detailed description and illustration thereof will be omitted. Only processing of the lens microcomputer 1116 D is shown in the flow chart of FIG. 20 .
As a means for identifying whether the camera main body is different from that before the power supply is turned off, identification information such as the number unique to the camera main body (any information unique to the camera main body, such as a serial number, can be used) is received in initial communication between the camera main body and the lens assembly and written in the memory in the lens microcomputer 1116 D.
The algorithm for controlling the lens assembly at the time of turning on the power supply in this modification will be described below with reference to FIG. 20 .
When the power supply is turned on in step S 2001 , the lens microcomputer 1116 D determines on the basis of the identification information obtained from the camera main body whether the camera main body mounted before turning off the power supply is exchanged with another camera main body.
If YES in step S 2002 , the flow advances to step S 2003 to confirm whether lens data is stored in the lens data memory unit 1133 of the lens microcomputer 1116 D.
This confirmation is also made to determine whether the memory holding power supply 1135 of the lens data memory unit 1133 of the lens microcomputer 1116 D has been normally operated.
If NO in step S 2003 , the flow advances to step S 2005 . If YES in step S 2003 , the flow advances to step S 2004 , and locus data including the position data of the focus lens and the variable power lens, the representative locus used, and the internal ratio are read out from the lens data memory unit 1133 into a focus control program 1117 and a computer zoom program 1119 of the lens microcomputer 1116 D. On the basis of these backup data, the positions of the focus lens and the variable power lens and the locus to be traced are determined. The positions of the focus lens and the variable power lens and the control state are returned to those before the power supply is turned off, and the flow advances to step S 2006 .
If NO in step S 2002 , or if NO in step S 2003 , the lens positions and cam locus are initialized in the lens assembly to set the focus lens and the variable power lens at their initial positions, and the flow advances to step S 2006 .
When the power ON sequence is completed, and a normal operation is started, in step S 2006 , the current lens positions and locus in the lens microcomputer 1116 D are written in the lens data memory unit 1133 at a predetermined period (e.g., an integer multiple of the vertical sync signal of a video signal) such that the data can be stored even when the power supply is turned off.
With this arrangement, when an exchange operation is performed between the lens assembly and the camera main body before or after the power supply is turned off, the initialization operation for the focus lens and the variable power lens is performed upon repowering. If the exchange operation is not performed between the lens assembly and the camera main body before or after the power supply is turned off, the state before the power supply is turned off is read out from the lens data memory unit 1133 , so that the state before the power supply is turned off can be restored.
Even when the power supply is turned off, the state before turning off can be reproduced at the time of repowering as long as the combination of the lens assembly and the camera main body is not changed. The state is not reset every time the power supply is turned on/off, so that the sensing state before the power supply is turned off can be continued.
As long as the lens assembly is not exchanged, the initialization operation for the lens assembly is not performed regardless of the ON/OFF operation of the power supply. The sensing operation can be continued while the state before turning off the power supply is set as an initial state, resulting in an improvement in operability. In addition, since the ON/OFF operation of the power supply does not affect the sensing state, the power supply can be frequently turned on/off, and a power saving effect can be obtained.
FIG. 21 is a block diagram showing the arrangement of the second modification of the fourth embodiment of the present invention. The same reference numeral as in the fourth embodiment denote the same elements in the second modification, and a detailed description thereof will be omitted.
In this modification, the data holding power for storing the lens data in the fourth embodiment is supplied from the camera main body. With this arrangement, even when the power supply of the camera main body or the lens assembly is turned off, the lens data memory unit can be backed up as long as the lens assembly is not detached, so the data can be held.
In the fourth embodiment and the first modification of the fourth embodiment, a memory holding battery is used to store lens data in the lens microcomputer. Instead, an EEPROM or a nonvolatile memory such as a flash memory may be used.
Fifth Embodiment
The fifth embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 22 is a block diagram showing an example in which the present invention is applied to an interchangeable lens video camera. AF control and a zooming operation in this embodiment are the same as those in the above-described embodiments. Hence, a detailed description is omitted, and only different portions will be described.
Light from an object passes through a fixed first lens group 2101 , a second lens group (to be referred to as a variable power lens hereinafter) 2102 for performing a zooming operation, an iris stop 2103 , a fixed third lens group 2104 , and a fourth lens group (to be referred to as a focus lens hereinafter) 2105 having both a focusing function and a function of compensating for the movement of a focal plane caused by zooming. The red, green, and blue components in the three primary colors form images on the image sensing surfaces of image sensing devices 2106 , 2107 , and 2108 such as CCDs, respectively.
The images of the respective color components, which are formed on the image sensing surfaces of the image sensing devices, are photoelectrically converted, amplified to their respective optimum levels by amplifiers 2109 , 2110 , and 2111 , input to a camera signal processing circuit 2112 , and converted into a standard TV signal.
The video signal output from the camera signal processing circuit 2112 is supplied to a video recorder and an electronic viewfinder (neither are shown) through a switch 2140 , so that recording and monitoring are enabled.
By switching the switch 2140 , immediately preceding recorded image information can be reproduced with the video recorder to check the recording state (so-called “rec review”).
The luminance signal generated in the camera signal processing circuit 2112 is input to an AF signal processing circuit 2113 . Though not illustrated in FIG. 22, information associated with the luminance signal level is sent from the camera signal processing circuit 2112 to a lens microcomputer 2116 in the lens assembly. On the basis of this information, control for opening/closing the iris stop 2103 and maintaining a predetermined luminance signal level is performed. The aperture opening amount of the iris stop is detected by an encoder 2129 and used as the depth-of-field information for AF control or manual iris stop control.
The AF signal processing circuit 2113 detects the high-frequency component in the luminance signal, which changes according to the focus state, as an AF evaluation value. The AF evaluation value is read out by a data read program 2115 in a main body microcomputer 2114 in a camera main body 2128 and transferred to the lens microcomputer 2116 .
The microcomputer 2114 loads the information of a power switch 2138 of the camera. When the power switch 2138 is turned on, the main body microcomputer controls a switch 2139 to supply power from a battery (not shown) arranged in the camera main body to a lens assembly 2127 side.
In addition to the AF evaluation value, a lens ON/OFF request signal 2142 for performing ON/OFF control on the lens assembly side, a lens key inhibition signal 2145 for inhibiting the operation of operation keys on the lens assembly side, and the like are transmitted from the microcomputer 2114 to the lens assembly side.
The camera main body receives, from the lens assembly 2127 side, an image display permission signal 2143 for permitting to supply a video signal output from the camera signal processing circuit 2112 to the electronic viewfinder or the video recorder and display an image, and a lens OFF permission signal 2144 representing that the power supply on the lens side can be turned off, thereby performing control according to the operation state of the lens assembly.
The lens microcomputer 2116 loads the states of an AF switch (when ON, an AF operation is performed; when OFF, a manual mode is set) 2131 , a zoom switch 2136 for operating the variable power lens to the telephoto side (T) or the wide side (W) to perform a zooming operation, and a power focus switch 2137 for operating the focus lens to the closest focusing distance or in the direction of infinity when the AF switch is OFF in the manual focus state, so that control according to the operation states of the switches is performed.
When the AF switch 2131 is OFF, and the zoom switch 2136 is depressed, the lens microcomputer 2116 sends a signal to a zoom motor driver 2122 such that the variable power lens is driven in the direction operated by a computer zoom program 2119 , i.e., to the telephoto side or the wide side, thereby driving the variable power lens 2102 through a zoom motor 2121 . At the same time, to compensate for the position of the focal plane corresponding to the movement of the variable power lens, the focus motor 2125 is driven through a focus motor driver 2126 on the basis of lens cam data (FIG. 22) stored in the lens microcomputer 2116 in advance to drive the focus lens 2105 .
When the AF switch 2131 is ON (AF mode), and the zoom switch 2136 is depressed, it is necessary to hold the in-focus state while compensating for the displacement of the focal plane caused by the zooming operation and a blur generated according to the movement of the lens relative to the object. Accordingly, the computer zoom program 2119 operates to not only perform control on the basis of the lens cam data 2120 stored in the lens microcomputer 2116 in advance but also simultaneously refer to the AF evaluation value signal sent from the main body microcomputer 2114 , thereby performing a zooming operation while holding the position at which the AF evaluation value is maximized.
When the AF switch 2131 is ON, and the zoom switch 2136 is not depressed, the AF program 2117 sends a signal to the focus motor driver 2126 such that the AF evaluation value signal transmitted from the main body microcomputer 2114 is maximized to drive the focus lens 2105 through the focus motor 2125 , thereby performing an automatic focusing operation.
When the AF switch 2131 is OFF (manual mode), and the zoom switch 2136 is not depressed, a signal is sent to the focus motor driver 2126 to drive the focus lens 2105 in the direction operated by the power focus switch (manual focus switch) 2137 , i.e., to the closest focusing distance or the direction of infinity, thereby performing manual focusing.
The sequence from turning on to turning off the camera will be described below with reference to FIGS. 22 and 23.
When the power switch 2138 of the camera is turned on at time t 0 , the main body microcomputer 2114 is powered. At time t 1 , the power switch 2139 for supplying a power to the lens assembly is turned on, and at the same time, the lens ON/OFF request signal 2142 goes high.
With this operation, the lens microcomputer 2116 initializes the lens assembly (lens reset). At time t 2 , initialization is completed, and the image display permission signal 2143 goes high. Completion of initialization of the lens assembly is transmitted to the camera 2128 accordingly.
Upon receiving the image display permission signal 2143 , the main body microcomputer 2114 on the camera side sets the lens key inhibition signal 2145 of low level to high level (the operation keys on the lens assembly side are enabled). At the same time, a video signal output from the camera signal processing circuit 2112 is output to the electronic viewfinder or the video recorder.
From time t 0 to time t 2 , the lens microcomputer 2116 inhibits the operations of the AF switches 2131 , the manual focus switch 2137 , and the zoom switch 2136 (the lens key inhibition signal 2145 is set at low level). However, when the lens key inhibition signal 2145 goes high, the AF switch 2131 , the manual focus switch 2137 , and the zoom switch 2136 are enabled.
At time t 3 , the rec review signal 2147 goes high. The switch 2140 is switched to the video recorder side, and the immediately preceding recorded video signal output from the reproducing unit is supplied to the viewfinder 2148 . Simultaneously, the lens key inhibition signal 2145 goes low.
With this operation, the lens microcomputer 2116 disables the AF switch 2131 , the manual focus switch 2137 , and the zoom switch 2136 . More specifically, during reproduction such as rec review, driving of the lenses on the lens assembly side is inhibited not to change the states of the respective switches.
At time t 4 , the rec review signal 2147 goes low, and at the same time, the switch 2140 is switched such that the video signal from the camera signal processing circuit 2112 is supplied to the viewfinder 2148 . The lens key inhibition signal 2145 goes high. With this operation, the lens microcomputer 2116 enables the AF switch 2131 , the manual focus switch 2137 , and the zoom switch 2136 .
When the camera power switch 2138 is turned off, the main body microcomputer 2114 sets the lens ON/OFF request signal 2142 to low level at time t 5 . Simultaneously, the lens key inhibition signal 2145 also goes low.
With this operation, the lens microcomputer 2116 starts preparation for turning off the power supply in the lens assembly. For example, the focus lens 2105 and the zoom lens 2102 are moved to predetermined positions. Simultaneously, the lens display permission signal goes low to inhibit display of a camera image. In addition, the AF switch 2131 , the manual focus switch 2137 , and the zoom switch 2136 are disabled.
That is, before the power supply is turned off, the movable units such as the lenses in the lens assembly are moved to predetermined positions before the power supply is turned off. In addition, an image with poor quality during this operation can be prevented from being displayed on the electronic viewfinder or the video recorder.
The lens microcomputer 2116 sets the lens OFF permission signal 2144 to high level at time t 6 at which preparation for turning off the power supply is completed. When the lens OFF permission signal 2114 goes high, the microcomputer 2114 turns off the switch 2139 to stop power supply to the lens assembly side. Thereafter, the power supply of the camera 2128 is turned off.
In this embodiment, the AF evaluation value 2141 , the lens ON/OFF request signal 2142 , the display permission signal 2143 , the lens OFF signal 2144 , the lens key inhibition signal 2145 , and the like are transferred between the camera main body 2128 and the lens assembly 2127 through dedicated signal lines. However, bidirectional serial or parallel data communication may be performed between the main body microcomputer 2114 and the lens microcomputer 2116 so that the respective contents are transferred at predetermined positions of data communication. In addition, the above-described embodiments, i.e., in-focus state adjustment processing, mounting of an AF signal processing circuit in the lens assembly, or holding of an in-focus state at the time of repowering may be combined with the processing of this embodiment, as a matter of course.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. | An interchangeable lens video camera system which can stably focus on a main target object under any conditions of the object or the environment. The camera system includes a lens assembly detachably attached to a camera for photoelectrically converting incident light to sense an image and output an image signal. The camera system further includes a zoom lens and a focus lens controlled on the basis of an automatic focus evaluation value and data associated with exposure which are received from the camera while referring to a lens cam data unit which stores locus information of the zoom lens and the focus lens in advance. The interchangeable lens video camera system allows for the reduction of blurring and degradation of image quality. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is concerned with the field of power semiconductor components and relates to a bilaterally controllable thyristor according to the preamble of the first claim.
2. Discussion of Background
A thyristor of the generic type is described for example in German Patent Application DE 44 39 012 A1. That document concerns a bilaterally controllable thyristor in which two reverse-connected parallel thyristor structures are integrated in a semiconductor substrate. The thyristor structures are decoupled on the component surfaces by a respective isolation region with a carrier lifetime that is preferably reduced. An isolation region between the thyristor structures is principally necessary for two reasons: firstly, in the event of one thyristor structure being triggered, no parasitic current paths to the other thyristor structure should be produced; also, no interaction between the two thyristor structures should occur during commutation. Although the solution according to the prior art may already be sufficient in many cases, undesirable migration of charge carriers from one thyristor structure that has already triggered to the other thyristor structure that has not yet triggered means that the switched-off thyristor structure can be destroyed by local, uncontrollable triggering.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel bilaterally controllable thyristor which is distinguished by improved decoupling between the two thyristor structures. In particular, the intention is that the switched-off structure cannot be triggered in an uncontrolled manner by undesirable migration of charge carriers. This object is achieved by means of the features of the independent claims.
The heart of the invention is that the degree of shorting of the cathode region increases toward the isolation region. This can be achieved by virtue of the fact that the density per unit area of the shortcircuit regions tends to a maximum value toward the isolation region. Moreover, the use of a linear, continuous short-circuit region running along the isolation region is particularly favorable.
In a preferred exemplary embodiment, further improved decoupling of the two thyristor structures is achieved by an essentially horseshoe-shaped region which is arranged in the region between the central gate regions and the adjacent anode region. The horseshoe-shaped region likewise contributes to the fact that the charge carriers injected into the gatecathode circuit cannot follow a parasitic current path between the gate region and the anode region of the other thyristor structure of the same main surface. The horseshoe-shaped region is advantageously produced by etching or by masked implantation of dopants in this region.
A further improvement in the isolation between the thyristor structures of a thyristor according to the invention is also achieved by virtue of the fact that the central gate region reaches laterally into the respective cathode region and is aligned with the corresponding anode emitter. In addition, an angle which is greater than zero and, in particular, is 45° should be spanned between the isolation region and any strengthening gate finger structure. The diametrically running isolation region should have a width of approximately 10 diffusion lengths of the minority charge carriers.
Further advantageous embodiments emerge from the corresponding dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a thyristor according to the invention from above.
FIG. 2 shows a thyristor according to the invention from underneath.
FIG. 3 shows a thyristor according to the invention in section along the line A--A of FIG. 1.
FIG. 4 shows a thyristor according to the invention in section along the line B--B of FIG. 1.
The reference numerals used in the drawings and their meanings are summarized in the List of Designations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 shows a thyristor 1 according to the invention from above. In a semiconductor body two thyristor structures are arranged between a first, top main surface 2 and a second bottom main surface 3 (visible in FIG. 2). The anode region 4 of the first thyristor structure, the cathode region 12 of the second thyristor structure, the central gate region 13 of the second thyristor structure, an edge termination region 18 and a strengthening gate finger structure 15 are visible from above. An isolation region 14 is provided between the thyristor structures. This isolation region 14 is horseshoe-shaped in a region surrounding the central gate 13 and is designed such that it has a particularly high impedance. Short-circuit regions 16 (only visible in the sectional views) are provided in the region of the second cathode region 12. In order to avoid undesirable migration of charge carriers from one thyristor structure that has already triggered to the other thyristor structure that has not triggered--this might bring about uncontrolled triggering of the thyristor structure that has not yet triggered--, the density of the short-circuit regions 16 increases toward the isolation region 14. At the boundary with the isolation region 14, said density reaches a maximum value, which is advantageously formed by a linear short-circuit region 17 running along the isolation region 14.
FIG. 2 shows the thyristor from underneath. The anode region 9 of the second thyristor structure, the cathode region 7 of the first thyristor structure, the central gate region 8 of the second thyristor structure, an edge termination region 18 and a strengthening gate finger structure 15 are visible on the second main surface 3. An isolation region 14 is likewise provided between the thyristor structures. This isolation region is likewise horseshoe-shaped around the central gate 8 and is designed such that it has a particularly high impedance. Short-circuit regions 16 (only visible in the sectional views) are likewise provided in the cathode region 7. In order to avoid undesirable migration of charge carriers from one thyristor structure that has already triggered to the other thyristor structure that has not triggered--this might bring about uncontrolled triggering of the thyristor structure that has not yet triggered--, the density of the short-circuit regions 16 increases toward the isolation region 14 in this case, too. At the boundary with the isolation region 14, said density reaches a maximum value, which is likewise advantageously formed by a linear short-circuit region 17 running along the isolation region 14. The isolation region 14 runs diametrically on both main surfaces 2 and 3 and has a width of approximately 10 diffusion lengths of the minority charge carriers.
FIGS. 1 and 2 additionally show the strengthening gate finger structure 15. In contrast to the prior art cited in the introduction, this strengthening gate finger structure 15 has no part which runs along the isolation region 14; rather an angle which is at least greater than zero and, preferably, is 45° is spanned between the isolation region 14 and the fingers 15 of the strengthening gate finger structure. As a result, the finger structure 15 ensures an efficient triggering reaction, on the one hand, but, on the other hand, prevents undesirable triggering in the region between the two thyristor structures.
FIG. 3 shows a detail of a thyristor according to the invention along the line A--A in section. The way in which a short-circuit region 17 is arranged along the isolation region 14 on both main surfaces 2 and 3 is clearly discernable. For reasons of production, the short-circuit region 17 may, as illustrated, be slightly spaced apart from the adjacent cathode region 12 or 7. The area density, that is to say the number of short-circuit regions 16 per unit area increases within the corresponding cathode region 7 or 12 toward the continuous, linear short-circuit region 17. The short-circuit regions 16 and the short-circuit region 17 short circuit the first and second p-type bases 6, 11 through the first and second cathode regions 7, 12, respectively, with a metallization layer which covers the cathode region and is not illustrated for the sake of clarity. The higher density of short-circuit regions 16 toward the isolation region and also, in particular, the continuous, linear short-circuit region 17 ensure that during turn-off, charge carriers are depleted sufficiently rapidly and an uncontrolled triggering leading to destruction can be avoided. Consequently, any charge carriers flow away not via the cathode region but via the short circuits. As a result, they do not cause any uncontrolled triggering either.
Moreover, the p-type bases 6 and 11 are dimensioned as continuous layers into which more highly doped anode emitter regions 4, 9 are diffused. On both sides, the isolation regions 14 are formed by surfacing parts of the p-type bases.
FIGS. 1 and 2 additionally reveal the horseshoe-shaped region 19 of the isolation region 14 which surrounds the central gate region 8, 13. The opening of the horseshoe faces the first and the second cathode region. The region 19 reinforces the isolation effect between the two thyristor structures and prevents the charge carriers injected into the gate-cathode circuit from being able to follow a parasitic current path between gate contact and the anode region of the other thyristor structure of the same main surface. The higher impedance can be achieved by etching an existing doping profile or by selective masked implantation of suitable dopants in the region of the region 19.
The shape of the central gate regions 8 and 13 is elongate and stretched into the cathode regions 7 and 12. That end of the central gate regions 8 and 13 which is situated nearest the respective cathode region is arranged exactly above the anode regions 4 and 9 of the same thyristor structure. This exact alignment likewise contributes to improved decoupling of the two thyristor structures and ensures, in particular, reproducible component properties.
FIG. 4 shows a section along the line B--B of FIG. 1. The way in which the p-type base surfaces between the central gate regions 13 and 8 and the adjacent anode regions 4 and 9 and forms the horseshoe-shaped isolation region 19 can be clearly seen. This isolation region is designed such that it has a particularly high impedance by omitting in this region an additional doping 22 which essentially determines the conductivity of the p-type bases 6 and 11 and is otherwise formed over the whole area (see FIG. 3). This can be done by etching an existing doping profile or by selective masked implantation of the p-doped layer 22 in the desired region. An n-doped auxiliary cathode 20 and a p+ doped contact region 21 are provided at that end of the central gate regions 13 and 18 which is opposite to the isolation region 19. They are then followed by the cathode region 12 with the short-circuit regions 16, whose density, as mentioned, increases toward the center of the component.
What is produced overall is a bidirectionally conducting thyristor whose decoupling between the two thyristor structures is greatly improved and can consequently be operated reliably in any operating situation.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A specification is given of a bidirectionally controllable thyristor which is distinguished by improved decoupling between the two thyristor structures. In particular, the intention is that the switched-off structure cannot be triggered in an uncontrolled manner by undesirable migration of charge carriers. This is achieved by virtue of the fact that the degree of shorting of the cathode region increases toward the isolation region. In particular, this can be achieved by virtue of the fact that the density per unit area of the short-circuit regions tends to a maximum value toward the isolation region. The use of a linear, continuous short-circuit region running along the isolation region is particularly favorable. (FIG. 1). | 7 |
This application is continuation of Ser. No. 09/141,767 filed Aug. 27, 1998 now U.S. Pat. No. 6,141,260.
TECHNICAL FIELD
This invention relates to integrated circuit memory devices, and, more particularly, to a method and apparatus for providing high density, high storage capacity, low power, nonvolatile memory devices.
BACKGROUND OF THE INVENTION
Single electron devices, and particularly single electron memory cells, are presently of great interest, due to potential advantages in memory cell size and power dissipation, compared to memory technologies currently in use. As used herein, the term “single electron device” refers to an electronic device capable of providing a repeatable and measurable response to the presence or absence of a single electron.
As device sizes have shrunk over the last several decades, the number of electrons contributing to the drain current in field effect transistors (“FETs”) used in memory devices has correspondingly decreased. Extrapolation from these trends suggests that in another decade, FETs will have drain currents including as few as ten electrons at a time. When so few electrons contribute to a current and therefore to a signal, normal fluctuations in the number of electrons present in a volume of semiconductor material can lead to uncertainty or error in the signal that the current represents.
Memories using single electron memory cells provide certainty in numbers of electrons representing data in a memory cell and therefore help to avoid problems due to fluctuations in the number of electrons that are present in a transistor at one time. Memory cells employing single electron transistors are also extremely simple and can be quite small. For example, a memory structure employing vertically stacked cells to provide an area per bit of 0.145 squared is described in “A 3-D Single-Electron-Memory Cell Structure with 2F 2 per bit” by T. Ishii et al. (IEDM 97), pp. 924-926.
The combination of size, power requirements and simplicity make single electron structures promising candidates for very high capacity memory integrated circuits. This is discussed in more detail in “Single-Electron-Memory Integrated Circuit for Giga-to-Tera Bit Storage” by K. Yano et al., 1996 Intl. Solid State Circuits Conf. (Feb. 9, 1996), pp. 266-267 and “A 128 Mb Early Prototype for Gigascale Single-Electron Memories” by K. Yano et al., 1998 Intl. Solid State Circuits Conf. (Feb. 7, 1998), pp. 344-345.
FIG. 1A is a simplified schematic diagram of a typical two-terminal single electron device 20 , in accordance with the prior art. The single electron device 20 includes first 22 and second 24 electrodes and an island 26 formed from conductive material, which may be semiconductor material, as discussed in U.S. Pat. No. 5,731,598, entitled “Single Electron Tunnel Device And Method For Fabricating The Same” issued to H. Kado et al. (Mar. 24, 1998). The first 22 and second 24 electrodes are each separated from the island 26 by small insulating gaps 28 , 28 ′. The first 22 and second 24 electrodes, the island 26 and the gaps 28 , 28 ′ are all collectively mounted on an insulating substrate 30 or are surrounded by an insulator. The gaps 28 , 28 ′ may be formed of any insulating material but must be small enough to allow conduction band electrons 32 (hereinafter “electrons”) to tunnel through them in response to a voltage V coupled across the first 22 and second 24 electrodes. The voltage V is provided by an external source, represented in FIG. 1A by a battery 34 .
A first condition for trapping one or more electrons 32 on the island 26 is that the resistance R between the island 26 and other structures on the substrate 30 must be greater than a quantum resistance R k , as is discussed, for example, in “Single-electron devices” by H. Ahmed et al., Microelectronic Engineering 32 (1996), pp. 297-315, and “Single electron electronics: Challenge for nanofabrication” by H. Ahmed, J. Vac. Sci. Technol. B 15(6) (November/December 1997), pp. 2101-2108. When the first 22 and second 24 electrodes and the island 26 are mounted on the insulating substrate 30 and are surrounded by an insulator such as air, a primary resistance R between the island 26 and any other structure is set by tunneling resistances R t associated with the gaps 28 , 28 ′ separating the island 26 from the first 22 and second 24 electrodes. The quantum resistance R k equals h/q 2 , or about 26 kΩ, where h is Planck's constant and q represents the charge of a single electron. This first condition will be satisfied for all of the examples considered herein but is included for completeness sake.
A second condition is that allowed states for these electrons 32 must be separated from a conduction band edge E C by an “electron charging energy” that is given as q 2 /2C, where C represents a capacitance of the island 26 . In other words, a first electron 32 that is introduced onto the island 26 will occupy an allowed state having a potential energy that is greater than that of the conduction band edge E C for the material forming the island 26 by q 2 /2C.
A third condition is that, for the electron or electrons 32 to be trapped on the island 26 , the electron charging energy q 2 /2C must be substantially greater than an average thermal energy kT, or q 2 /2C>kT, where k represents Boltzmann's constant and T represents temperature in Kelvin. The capacitance C must be on the order of one attoFarad for electrons 32 to be trapped on the island 26 for any appreciable length of time at room temperature (kT=0.026 eV at room temperature). For example, an island 26 having a capacitance of 10 −16 F is about 100 nanometers in diameter but can only exhibit single-electron effects at temperatures at or below about 4 Kelvin. Islands 26 having diameters of one to five nanometers exhibit significant single-electron effects at room temperature (circa 300 K).
FIG. 1B is a simplified potential energy diagram for the device 20 of FIG. 1A showing a potential well 40 , in accordance with the prior art. FIG. 1B shows Fermi levels (“E F ”) 42 , 44 in the first 22 and second 24 electrodes, respectively, a lowest allowed state 46 for one electron 32 in the potential well 40 on the island 26 , and energy barriers 48 , 48 ′ associated with insulating materials forming the gaps 28 , 28 ′, respectively. An important property of the device 20 of FIG. 1A is that no significant current can flow through the device 20 until a magnitude of the potential V due to the external source 34 equals or exceeds the electron charging energy or V≧q 2 /2C. FIG. 1C is a simplified potential energy diagram illustrating the potential V setting the Fermi level 42 at the left side of the Figure equal to the lowest allowed state of the potential well 40 , i.e., at the onset of conduction, in accordance with the prior art.
FIG. 1D is a simplified graph of an I-V characteristic 50 for the device 20 of FIG. 1A, in accordance with the prior art. The I-V characteristic 50 shows essentially no conduction until the applied voltage V reaches a threshold V C , causing the Fermi level 42 on the electron supply side to be equal to the electron charging energy q 2 /2C. The region of essentially no conduction is known as the Coulomb blockade region. When the applied voltage V reaches the threshold V C , known as the Coulomb gap voltage, the energy barrier effectively vanishes. Linear I-V dependence is seen in FIG. 1D for voltages having an absolute magnitude exceeding V C .
FIG. 2 is a simplified schematic illustration of a typical field effect transistor (“FET”) 60 that includes the island 26 of FIG. 1A for storing one or more electrons 32 , in accordance with the prior art. The FET 60 includes all of the elements of the two-terminal device 20 of FIG. 1 and additionally includes a gate 62 having a capacitance C G and a gate bias supply 64 . The gate bias supply 64 includes a first electrode coupled to the gate 62 and a second electrode coupled to one side of the supply 34 providing the voltage V. The FET 60 has a channel 66 formed from semiconductor material that is coupled to the first 22 and second 24 electrodes.
Several examples of FETs 60 capable of providing repeatable output signals indicative of single electron 32 storage on the islands 26 are described in “A Room-Temperature Silicon Single-Electron Metal-Oxide-Semiconductor Memory With Nanoscale Floating-Gate and Ultranarrow Channel” by L. Guo et al., Appl. Phys. Lett. 70(7) (Feb. 17, 1997), pp. 850-852 and “Fabrication And Characterization of Room Temperature Silicon Single Electron Memory” by L. Guo et al., J. Vac. Sci. Technol. B 15(6) (November/December 1997), pp. 2840-2843. Similar FETs 60 are described in “Room Temperature Operation of Si Single-Electron-Memory with Self-Aligned Floating Dot Gate” (IEDM 1996), pp. 952-954, Appl. Phys. Lett. 70(13) (Mar. 31, 1997), pp. 1742-1744 and “Si Single Electron Tunneling Transistor With Nanoscale Floating Dot Stacked on a Coulomb Island by Self-Aligned Process,” Appl. Phys. Lett. 71(3) (Jul. 21, 1997), pp. 353-355, all by A. Nakajima et al. These FETs 60 employ feature sizes as small as 30 nanometers and require much closer alignment between elements than 30 nanometers. Formation of such small feature sizes using electron beam lithography does not presently lend itself to mass production.
These FETs 60 employ a floating island 26 between the gate 62 and the channel 66 to modulate conductivity in the channel 66 . In these FETs 60 , the island 26 spans the width of the channel 66 .
It will be appreciated that other techniques for forming the islands 26 may be employed. For example, shallow implantation of relatively high doses (e.g., ca. 5-50×10 14 /cm 2 ) of silicon or germanium at relatively low energies (e.g., ca. 20 keV) into relatively thin (e.g., ca. 5-20 or more nanometers) silicon dioxide layers, followed by annealing, provides nanocrystals of the implanted species that are insulated from each other and from an underlying silicon region, as described in “Fast and Long Retention-Time Nano-Crystal Memory” by H. Hanafi et al., IEEE Trans. El. Dev., Vol. 43, No. 9 (September 1996), pp. 1553-1558. Performance of memories using islands 26 formed from nanocrystals in proximity to the channel 66 is discussed in “Single Charge and Confinement Effects in Nano-Crystal Memories” by S. Tiwari et al., Appl. Phys. Lett. 69(9) (Aug. 26, 1996), pp. 1232-1234.
Prior art FETs may provide multiple islands 26 between the gate 62 and the channel 66 , and are capable of storing multiple electrons 32 . As a result, these FETs are analogous to conventional flash memories and are capable of multilevel signal storage and readout. An example of an arrangement for discriminating between multiple signal levels that may represent a stored signal is given in “Novel Level-Identifying Circuit for Multilevel Memories” by D. Montanari et al., IEEE Jour. Sol. St. Cir., Vol. 33, No. 7 (July 1998), pp. 1090-1095.
FETs 60 including one or more islands 26 suitable for capture of electrons 32 thus are able to provide measurable and repeatable changes in their electrical properties in response to capture of the electron or electrons 32 on at least one island 26 . Moreover, these FETs 60 provide these changes in a convergent manner, i.e., the changes may be produced by storage of a single electron 32 and storage of that single electron 32 can inhibit storage of another electron 32 . In this way, some of the FETs 60 avoid some problems due to number fluctuations in the population of electrons 32 that could otherwise be troublesome for FETs 60 having very small populations of electrons 32 .
Additionally, the energy barriers 48 , 48 ′ cause the single electron device 20 and the FETs 60 to store trapped electrons 32 for significant periods of time, even in the absence of externally applied electrical power (e.g., voltage sources 34 , 64 ). As a result, a nonvolatile memory function is provided by these devices 20 and FETs 60 .
While single electron devices 20 and FETs 60 show great promise as memory cells for very high density memory arrays, fabrication difficulties prevent mass production of memory arrays using these devices 20 , 60 as memory cells. Difficulties in regulating the size of the island or islands 26 and the thickness of the surrounding dielectric materials forming the gaps 28 , 28 ′ cause problems, particularly with respect to uniformity of device characteristics across many similar devices on a wafer or substrate. Difficulties in realizing the fine line interconnections (e.g., ca. 0.4 micron pitch) and other needed elements also cause poor yields in fabrication of these devices 20 , 60 .
There is therefore a need for a method for fabricating single electron devices that is robust and that provides reproducible single-electron device characteristics.
SUMMARY OF THE INVENTION
In one aspect, the present invention includes a memory cell having a first electrode coupled to a first location on semiconductor material, a second electrode coupled to a second location disposed away from the first location on the semiconductor material and a plurality of islands of conductive material having a maximum dimension of three nanometers and surrounded by an insulator having a thickness of between five and twenty nanometers. The islands and the insulator are formed in pores extending into the semiconductor material between the first and second electrodes. As a result, electrons may tunnel into or out of the islands with the assistance of externally-applied fields. The capacitance of the islands is small enough that single electrons stored on the islands provide consistent, externally observable changes in the memory cells.
In other aspects, the present invention provides methods for reading data from, writing data to and erasing memory cells capable of storing data by the presence or absence of a single electron in an island of conductive material contained in the memory cells. The reading, writing and erasing operations may be accompanied by a verification process that compensates for stored charge, trap generation and the like that otherwise might obscure desired data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a simplified schematic diagram of a typical two-terminal single electron device, in accordance with the prior art.
FIG. 1B is a simplified potential energy diagram for the device of FIG. 1A, in accordance with the prior art.
FIG. 1C is a simplified potential energy diagram, illustrating the potential V setting the Fermi level at the left side of the figure equal to the lowest allowed state of the potential well of FIG. 1B, in accordance with the prior art.
FIG. 1D is a simplified graph of an I-V characteristic for the device of FIG. 1A, in accordance with the prior art.
FIG. 2 is a simplified schematic illustration of a typical field effect transistor that includes the island of FIG. 1A for storing one or more electrons, in accordance with the prior art.
FIG. 3A is a simplified plan view of a memory device including memory cells employing single electron memory devices having electrical characteristics similar to those of the devices of FIGS. 1 and 2, in accordance with embodiments of the resent invention.
FIG. 3B is a simplified isometric view of a single electron resistor memory device in the memory cell of FIG. 3A, in accordance with embodiments of the Present invention.
FIG. 3C is a simplified cross-sectional view of the device of FIG. 3B, showing islands included within the semiconductor material of the body, in accordance with embodiments of the present invention.
FIG. 4 is a simplified flow chart of a process for reading the memory cell of FIGS. 3A-C, in accordance with embodiments of the present invention.
FIGS. 5 and 6 are simplified flow charts for processes for writing data to the memory cell of FIGS. 3A-C and for erasing data stored in the memory cell, respectively, in accordance with embodiments of the present invention.
FIG. 7 is a graph representing storage and erase time estimates for various energy barriers, in accordance with embodiments of the present invention.
FIG. 8 is a simplified flowchart of a process for forming the islands of FIGS. 1 and 2, in accordance with embodiments of the present invention.
FIGS. 9A, 9 B, 9 C, 9 D and 9 E are simplified cross-sectional views of the islands as they are being formed using the process of FIG. 8, in accordance with embodiments of the present invention.
FIG. 10 is a simplified block diagram of a computer system including the memory device of FIGS. 3A-C, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3A is a simplified plan view of a memory device 72 including a memory cell 73 having electrical characteristics similar to those of the devices 20 and 60 of FIGS. 1 and 2, in accordance with embodiments of the present invention. The memory device 72 includes a column addressing circuit 74 coupled to a plurality of column address lines 75 , and a row addressing circuit 76 coupled to a plurality of row address lines 77 . The memory cell 73 is located at an intersection of a column address line 75 and a row address line 77 and is addressed by activation of the column 75 and row 77 address lines coupled to the memory cell 73 , as is discussed below in more detail.
FIG. 3B is a simplified isometric view of a single electron resistor memory device 80 in the memory cell 73 of FIG. 3A, in accordance with embodiments of the present invention. The device 80 includes a body 82 having first 84 and second 86 electrodes formed at opposing ends. In one embodiment, the first 84 and second 86 electrodes form low resistance contacts to the body 82 . In one embodiment, the body 82 includes n-type semiconductor material having a donor concentration of about 10 15 /cm 3 or less and the first 84 and second 86 electrodes are N+ ohmic contacts to the body 82 . The first electrode 84 is coupled to a row address line 77 and the second electrode 86 is coupled to a column address line 75 .
The device 80 also optionally includes one or more gates 88 , 88 ′ coupled to one or more erase lines 90 , 90 ′ for erasing data stored in the device 80 . In one embodiment, the gates 88 , 88 ′ are formed from polysilicon using conventional processing techniques.
FIG. 3C is a simplified cross-sectional view of the device 80 of FIG. 3B, showing islands 26 (see FIGS. 1 and 2) included within the semiconductor material 98 forming the body 82 of the device 80 , in accordance with embodiments of the present invention. Each island 26 is surrounded by a dielectric 100 that provides the energy barriers 48 , 48 ′ (FIGS. 1B and C) associated with the gaps 28 , 28 ′, which insulate the island 26 from other islands 26 and from the semiconductor material 98 .
The device 80 of FIGS. 3A-C has a first state exhibiting a first current-voltage characteristic when no electrons 32 are stored on the islands 26 within the device 80 . The device 80 has a second state exhibiting a second current-voltage characteristic when one or more electrons 32 are stored in one or more islands 26 contained in the body 82 of the device 80 . In the second state, less current between the first electrode 84 and the second 86 electrode for a given voltage difference between the first 84 and second 86 electrodes than in the first state, and this difference may be detected by sensing circuitry (not illustrated) coupled to the column 75 or the row 77 address lines. Processes for switching the device 80 between the first and second states by storage and removal of electrons 32 from the island or islands 26 in the body 82 of the device 80 are explained in more detail below.
To store one or more electrons 32 in the body 82 of the device 80 , the column address line 75 is coupled to a first voltage (e.g., ground) and the row address line 77 is coupled to a second voltage (e.g., four volts) sufficient to cause single electrons 32 (FIG. 1) to tunnel into and to be stored on one or more of the islands 26 in the body 82 of the device 80 , as is explained below in more detail with reference to FIG. 5 . As a result, the device 80 changes from the first state to the second state.
To erase information represented by one or more stored electrons 32 stored on the island or islands 26 within the body 82 of the device 80 , the row 77 or column 75 (or both) address line is coupled to an electron sink (e.g., ground). The body 82 is depleted of mobile charge carriers by an externally-applied bias, which also tilts the barriers 48 , 48 ′ and results in field-assisted tunneling of electrons 32 stored in the potential wells 40 of the islands 26 from the islands 26 into the body 82 . In one embodiment, a negative potential is applied to one or more gate electrodes 88 , 88 ′ sufficient to completely deplete the semiconductor material 98 forming the body 82 of mobile charge carriers (i.e., electrons 32 or holes) to allow any stored electrons 32 to tunnel out of the island or islands 26 . Electrons 32 tunneling out of the islands 26 are removed from the semiconductor material 98 by electrical fields induced by the voltage applied to the gate electrodes 88 , 88 ′. As a result, the device 80 is restored to the first state.
A change in a current I between the first 84 and the second 86 electrode, corresponding to a difference ΔI in the current I between the first and second states, can be estimated as follows. The body 82 of the device 80 has a cross-sectional area A, a length L between the first 84 and second 86 electrodes and a number n T of electrons 32 trapped on the islands 26 . A conductivity σ for the semiconductor material 98 , as could be measured between the first 84 and second 86 electrodes, is given by nqμA/L, where μ represents the electron mobility and n represents the number of mobile charge carriers (electrons 32 ) per cubic centimeter. Assuming that each of the n T trapped electrons 32 results in one fewer mobile electron 32 per cubic centimeter, the change in current ΔI through the device 80 may be estimated as ΔI=(n T /AL)(qμAV/L)=n T qμVL 2 . A voltage V of one volt, a mobility μ of 600 cm 2 /(v-sec) and a length L of one micrometer corresponds to a decrease in current ΔI due to one stored electron 32 of 10 nanoamperes.
In one embodiment, the body 82 of the device 80 may have a length L of about one micrometer (10 −4 cm) and have a cross-sectional area A of about 10 −8 cm 2 . A free carrier concentration of 10 15 /cm 3 or less allows the gates 88 , 88 ′ to be able to deplete the semiconductor material 98 with relatively low applied voltages.
FIG. 4 is a simplified flow chart of a process 120 for reading the memory cell 73 of FIG. 3A, in accordance with embodiments of the present invention. The process 120 begins in a step 122 by activating one of the column address lines 75 and one of the row address lines 77 of FIGS. 3A-C to address one of the memory cells 73 . In a step 124 , a bias current I B or voltage V B is applied to the addressed memory cell 73 , as is discussed below in more detail. In a step 126 , the addressed memory cell 73 is coupled to a sensing circuit (not shown). In some embodiments, a query task 128 then compares a measured response X M to a threshold X T to determine if a logical “1” or a logical “0” is stored in the memory cell 73 as is described below in more detail.
In one embodiment, when a bias current I B is supplied from a current source (not shown) to, for example, the first electrode 84 of the addressed memory cell 73 , the measured response X M is a voltage, measured, for example, across the first 84 and second 86 electrodes. When the query task 128 determines that the measured response X M exceeds the threshold X T , at least one electron 32 is stored in the memory cell 73 and the memory cell 73 is storing a first logical state. When the query task 128 determines that the measured response X M does not exceed the threshold X T , no electron 32 is stored in the memory cell 73 and the memory cell 73 is storing a second logical state.
Conversely, in another embodiment, when a bias voltage V B is supplied from a voltage source (not shown) to, for example, one or both of the gates 88 , 88 ′ of the addressed memory cell 73 , the measured response X M is a current, measured, for example, at the first electrode 84 . When the query task 128 determines that the measured response X M exceeds the threshold X T , no electron 32 is stored in the memory cell 73 and the memory cell 73 is in the second logical state. When the query task 128 determines that the measured response X M does not exceed the threshold X T , at least one electron 32 is stored in the memory cell 73 and the memory cell 73 is in the first logical state.
When the query task 128 determines that the memory cell 73 is in the first logical state, the comparison circuit indicates that the memory cell 73 is in the first logical state, e.g., that a logical “1” is stored in the memory cell 73 , in a step 130 . When the query task 128 determines that the memory cell 73 is in the second logical state, the comparison circuit indicates that a logical “0” is stored in the memory cell 73 in a step 132 . The process 120 ends following either step 130 or step 132 .
In another embodiment, the query task 128 discriminates between a plurality of different logical values or states that may be stored in the memory cell 73 by comparing the measured response X M to a plurality of thresholds X Ti . An example of an arrangement for discriminating between multiple signal levels that may represent a stored signal is given in “Novel Level-Identifying Circuit for Multilevel Memories” by D. Montanari et al., IEEE Jour. Sol. St. Cir., Vol. 33, No. 7 (July 1998), pp. 1090-1095. An example of a circuit and method for programming, reading and erasing multiple single electron differences in the FETs 80 of FIGS. 3A-C is given in “Multi-State Flash Memory Cell and Method for Programming Single Electron Differences” by L. Forbes, U.S. Pat. No. 5,740,104. After the query task 128 determines the correct logical value for the data stored in the memory cell 73 , the data comparison circuit indicates the correct logical value in steps 130 - 132 and the process 120 ends.
FIGS. 5 and 6 are simplified flow charts for processes 140 and 160 for writing data to the memory cell 73 of FIG. 3 A and for erasing data stored in the memory cell 73 , respectively, in accordance with embodiments of the present invention. The processes 140 and 160 both use a verification process similar to a conventional verification process used with flash memories to compensate for variations in memory cell characteristics from one memory cell 73 to another, as is described in “Verify: Key to the Stable Single-Electron-Memory Operation” by T. Ishii et al. (1997 IEDM), pp. 171-174.
With reference now to FIG. 5, the write process 140 begins in a step 142 by activating one of the column address lines 75 and one of the row address lines 77 of FIGS. 3A-C to address one of the memory cells 73 . In a step 144 , a write pulse, which may be either a current I W or a voltage V W pulse, is applied to the addressed memory cell 73 . In some embodiments, the step 144 is used to write a binary value to the memory cell 73 . In other embodiments, the step 144 is used to write one of a plurality of possible values or data entries to the memory cell 73 by injecting a controlled number of electrons 32 into the islands 26 of the memory cell 73 .
In a step 146 , an index variable n, corresponding to a number of write cycles applied to this memory cell during this write process 140 , is incremented. In a step 148 , the memory cell 73 is read by sampling a voltage or current associated with the memory cell 73 , i.e., the process 120 of FIG. 4. A query task 150 then compares the read data to the data written to the memory cell 73 in the step 144 .
When the query task 150 determines that the read data and the write data agree, the process 140 ends. When the query task 150 determines that the read data and the write data do not agree, control passes to a query task 152 to determine if a maximum number of cycles N has been reached (i.e., is n≧N?). The maximum number of cycles N is despite differences in programming time between memory cells 73 , without wasting excessive amounts of time in attempts to program defective memory cells 73 . When the query task 152 determines that the maximum number of cycles N has not been reached, control passes to the step 144 , and steps 144 - 150 or 152 repeat. When the query task 152 determines that the maximum number of cycles N has been reached, a step 154 records that a write failure has occurred and the process 140 ends.
In some embodiments, the record of a write failure that is generated in the step 154 may be used to construct a conventional memory map describing addresses of defective memory cells 73 . Memory maps are used in order to avoid writing data to, or attempting to write data to, or reading data from, memory cells 73 that are defective. In some embodiments, the record of a write failure that is generated in the step 154 may be used to replace defective memory cells 73 with memory cells 73 that are known to be working properly, as is conventional in fabrication and repair of memory devices such as dynamic random access memories.
In the step 144 , where a write pulse is applied to the memory cell 73 , a finite number of electrons 32 are injected into the island or islands 26 . A probability of write failure is finite and nonzero because injection of electrons 32 into the potential wells 40 (FIG. 1C) is essentially stochastic. For example, a failure probability of 0.1% is unacceptable in modern memory devices. Additionally, characteristics of the memory cell 73 may change with time, due to generation of new trapping centers or by trapping of charge in or near the memory cell 73 .
Reading data from the memory cell 73 after a write pulse has been applied to the memory cell allows determination that a write failure has occurred. By making the write pulses I W or V W longer as n increases, the probability of trapping the desired number of electrons 32 increases substantially and may approach unity. In one embodiment, a width W W of the write pulses I W or V W depends geometrically on n, e.g., W W (n) ∝ 2 n , n ∈ {I}. In another embodiment, the amplitude of the write pulses depends arithmetically on n, e.g., V W (n) ∝ V W (o)(1+n/M), n ∈ {I}, where V W (o) represents an initial value and M represents a proportionality constant.
With reference now to FIG. 6, the erase process 160 begins in a step 162 by activating one or more of the column address lines 75 and one or more of the row address lines 77 of FIGS. 3A-C to address one or more of the memory cells 73 . In one embodiment, the step 162 selects a group of memory cells 73 , which may be a subset of the memory cells on one memory device 72 , may be all of the memory cells 73 on a memory device 72 or may include memory cells 73 from more than one memory device 72 . In a step 164 , an erase pulse, which may be either a current I E or voltage V E , is applied to the addressed memory cell 73 . In one embodiment, the erase pulse is applied to one or both of the erase gates 88 , 88 ′, with one or both of the electrodes 84 , 86 coupled to a suitable electron sink. In a step 166 , an index variable n, corresponding to a number of erase cycles applied to this memory cell 80 during this erase process 160 , is incremented. In a step 168 , the memory cell 73 is read by sampling a voltage or current associated with the memory cell 73 . A query task 170 then compares the read data to an expected value (e.g., corresponding to an absence of stored electrons 32 ) to determine if the contents of the memory cell 73 were erased in the step 164 .
When the query task 170 determines that the contents of the memory cell 73 were erased, the process 160 ends. When the query task 170 determines that the contents of the memory cell 73 were not erased, control passes to a query task 172 to determine if a maximum number of cycles N has been reached (i.e., is n≧N?). As with the write process 140 of FIG. 5, N is chosen to balance differences in erase time from one memory cell 73 to another memory cell 73 without spending excessive time to erase defective memory cells 73 . When the query task 172 determines that the maximum number of cycles N has not been reached, control passes back to the step 164 , and steps 164 - 170 or 172 repeat. In accordance with embodiments of the invention, the erase pulses V E may be varied with n as described above for the write pulses I W or V W in connection with the process 140 of FIG. 5 . When the query task 172 determines that the maximum number of cycles N has been reached, a step 174 records that an erase failure has occurred The process then 160 ends.
In one embodiment, individual memory cells 73 are erased as needed for storage of new data. In another embodiment, all of the memory cells 73 in a group or in an entire memory device 72 are erased en masse, by addressing a group of memory cells 73 in the step 162 and application of the erase pulses in the step 164 to all of the memory cells 73 in the group or in the memory device 72 simultaneously. The steps 166 - 174 are then carried out for each memory cell 73 individually, with a step of addressing the individual memory cells 73 being carried out prior to the step 166 of incrementing the index variable n. In another embodiment, the memory cells are erased en masse, however, the steps 166 - 174 are carried out as steps 146 - 154 of the verified write process 140 of FIG. 5 .
An advantage of en masse erasure is that the erase process 160 is slow, typically requiring milliseconds. Erasure of the entire memory device 72 one memory cell 73 at a time takes much longer than erasure of the entire memory device 72 en masse, and this is more exaggerated as the number of memory cells 73 in the memory device 72 increases.
Several factors affect storage times τ S , also known as latency, for memory cells 73 incorporating islands 26 for storage of one or more electrons 32 . In general, τ S ∝ e (ΔE/kT) e (d/d o ) , where ΔE represents the energy level difference between the energy barriers 48 , 48 ′ and the lowest allowed state in the island 26 and d/d o represents the relative thickness of the gaps 28 , 28 ′. Larger ΔE values or large d/d o values provide for longer storage times but also require higher write and erase pulse magnitudes and greater pulse durations. Additionally, ΔE is a function of the material forming the island 26 and the material forming the gaps 28 , 28 ′. The energy level difference ΔE may be estimated by subtracting the electron affinity χINS for the material forming the gaps 28 , 28 ′ from the electron affinity χISL for the material making up the island 26 and then adding the electron charging energy q 2 /2C, i.e., ΔE=χISL−χINS+q 2 /2C. Representative values for electron affinities χ for sever al materials are summarized below in Table I. Measured or achieved electron affinities χ depend strongly on surface treatment and surface contamination and may vary from the values given in Table I.
TABLE I
Electron affinities χ for selected materials.
χ (eV)
Material
Use
4.05
Si
Islands
3.6/3.7*
SiC
Islands
1.4**
C (diamond)
Islands
0.9-4.05
Silicon oxycarbide (projected)
Islands
0.9
SiO 2
Gaps
*depending on surface treatment.
**diamond can manifest different values, including negative values.
FIG. 7 is a graph representing estimated storage 176 and erase 178 time estimates for various island electron affinities χISL together with SiO 2 barriers in accordance with embodiments of the present invention. The left ordinate corresponds to a logarithm of retention time 176 at constant temperature, while the right ordinate corresponds to a logarithm of erase time 178 at constant erase voltage. Erase times 178 for the memory device 72 are determined by the height of the energy barrier 48 , 48 ′ (FIGS. 1B and C) surrounding the island 26 . Lower energy barriers 48 , 48 ′ require lower voltage, shorter erase pulses because lower energy barriers 48 , 48 ′ provide shorter tunneling distances and much higher tunneling probabilities. Short erase times 178 are desirable for some applications of electronically-erasable memories such as the memory device 72 .
Lower barriers 48 , 48 ′ also result in shorter retention times 176 due to thermal activation of electrons 32 over or through the energy barriers 48 , 48 ′. The islands 26 may be formed from silicon, from microcrystalline diamond-like films of Si (1−x) C x , with the composition ratio, x, ranging from 0.5 to one, or from silicon oxycarbide compounds, to provide electron affinities χ ranging between about 4.05 eV and 0.9 eV or less (see Table I), corresponding to energy barriers ΔE ranging from about 3.95 to about 0 eV (ignoring the charging voltage). By changing the composition of the islands 26 and the thickness of the surrounding insulator, and thus the height of the energy barriers 48 , 48 ′, charge retention times 176 can be changed from seconds, characteristic of DRAMs, to years, characteristic of hard disk drives. As a result, the memory device 72 can either be made to emulate a DRAM or a hard disk drive by varying the composition of the islands 26 . One device type can then perform all memory functions.
FIG. 7 illustrates that storage 176 and erase 178 times vary exponentially with the height of the energy barriers 48 , 48 ′. Presently, memories using polycrystalline silicon floating gates embedded in silicon dioxide are estimated to have charge retention times 176 of millions of years at 85° C. because the energy barriers 48 , 48 ′ are large (3.2 eV), resulting in erase times 178 in the millisecond range. The high electric fields required for erasure as a result of the large energy barriers 48 , 48 ′ may result in reliability problems or, in the worst case, lead to breakdown and catastrophic failure of the device 72 . An island 26 may be composed of a material of lower or adjusted energy barrier height, such as diamond-like compounds of silicon, carbon and oxygen, to provide desired energy barriers 48 , 48 ′. As a result, an acceptable retention time 176 can be established, whether seconds or years, by varying the relative concentrations of Si, C and 0 , thereby varying the electron affinity χ for the islands 26 . This then determines the height of the energy barriers 48 , 48 ′ and therefore, in part, the erase time 178 for a particular erase voltage.
FIG. 7 shows the concepts involved using rough order-of-magnitude estimates of the variations of storage and erasure times with barrier height. The same device structure can be used either as replacements for DRAMS or as replacements for hard disk drives. Only the composition of the island 26 needs to be changed in order to change the retention time and the erasure characteristics. This may be done on one integrated circuit so that radically different types of memory functions are realized on one integrated circuit.
FIG. 8 is a simplified flowchart of a process 180 for forming the islands 26 of FIGS. 1 and 2, and FIGS. 9A-9E are simplified cross-sectional views of the islands 26 as they are being formed using the process 180 of FIG. 8, in accordance with embodiments of the present invention. The process 180 (FIG. 8) begins in a step 182 with formation of voids or pores 202 (FIG. 9A) in a suitable silicon substrate or layer 98 (FIGS. 3 C and 9 A- 9 E). In one embodiment, the voids or pores 202 are formed by processes similar to those described in “Formation Mechanism of Porous Silicon Layers Obtained by Anodization of Monocrystalline n-type Silicon in HF Solutions” by V. Dubin, Surface Science 274 (1992), pp. 82-92. In one embodiment, a current density of between 5 and 40 mA/cm is employed together with 12-24% HF. In general, increasing N D (silicon donor concentration), HF concentration or anodization current density provides larger pores 202 and may lead to reentrant pores 202 . Pores 202 are readily and uniformly formed to have the desired characteristics when using simple and easily controlled processes.
In a step 184 , the silicon 98 including interiors of the pores 202 is oxidized to provide a thin oxide layer 100 (FIG. 9 B). In one embodiment, the silicon 98 is oxidized to provide the oxide layer 100 to have a thickness of between 2.5 and ten nanometers. The oxidation step 184 may be carried out using conventional oxidation techniques. In one embodiment, an inductively-coupled oxygen-argon mixed plasma is employed for oxidizing the silicon 98 , as described in “Low-Temperature Si Oxidation Using Inductively Coupled Oxygen-Argon Mixed Plasma” by M. Tabakomori et al., Jap. Jour. Appl. Phys., Part 1, Vol. 36, No. 9A (September 1997), pp. 5409-5415. In another embodiment, electron cyclotron resonance nitrous oxide plasma is employed for oxidizing the silicon 98 , as described in “Oxidation of Silicon Using Electron Cyclotron Resonance Nitrous Oxide Plasma and its Application to polycrystalline Silicon Thin Film Transistors,” J. Lee et al., Jour. Electrochem. Soc., Vol. 144, No. 9 (September 1997), pp. 3283-3287 and “Highly Reliable polysilicon Oxide Grown by Electron Cyclotron Resonance Nitrous Oxide Plasma” by N. Lee et al., IEEE El. Dev. Lett., Vol. 18, No. 10 (October 1997), pp. 486-488.
In a step 186 , a conductive material 204 (FIG. 9C) is formed over the surface of the silicon 98 and in the pores 202 . In some embodiments, semiconductor material 204 is deposited over the surface of the silicon 98 and in the pores 202 .
Examples of materials 204 that may be used in accordance with embodiments of the invention include the materials listed in Table I above. The material 204 within the pores 202 forms the islands 26 and is chosen to have an electron affinity χ that, together with the thickness d/d o and the electron affinity χ of the insulator 100 filling the gaps 28 , 28 ′ (FIGS. 1 A and 2 ), provides storage times in a range of from hours to days or longer, together with practical erase parameters.
In some embodiments, silicon oxycarbide is employed as the material 204 in the step 186 . A process for forming thin microcrystalline films of silicon oxycarbide is described in “Transport Properties of Doped Silicon Oxycarbide Microcrystalline Films Produced by Spatial Separation Techniques” by R. Martins et al., Solar Energy Materials and Solar Cells 41/42 (1996), pp. 493-517. A diluent/reaction gas (e.g., hydrogen) is introduced directly into a region where plasma ignition takes place. The mixed gases containing the species to be deposited are introduced close to the region where the growth process takes place, which is often a substrate heater. A bias grid is located between the plasma ignition and the growth regions, spatially separating the plasma and growth regions.
Deposition parameters for producing doped microcrystalline Si x :C y :O z :H films may be defined by determining the hydrogen dilution rate and power density that lead to microcrystallization of the grown film 204 . The power density is typically less than 150 milliWatts per cm 3 for hydrogen dilution rates of 90%+, when the substrate temperature is about 250° C. and the gas flow is about 150 sccm. The composition of the films may then be varied by changing the partial pressure of oxygen during film growth to provide the desired characteristics.
In some embodiments, SiC is employed as the material 204 in the step 186 . SiC films may be fabricated by chemical vapor deposition, sputtering, laser ablation, evaporation, molecular beam epitaxy or ion implantation. Vacuum annealing of silicon substrates is another method that may be used to provide SiC layers having thicknesses ranging from 20 to 30 nanometers, as described in “Localized Epitaxial Growth of Hexagonal and Cubic SiC Films on Si by Vacuum Annealing” by Luo et al., Appl. Phys. Lett. 69(7) (1996), pp. 916-918. Prior to vacuum annealing, the substrates are degreased with acetone and isopropyl alcohol in an ultrasonic bath for fifteen minutes, followed by cleaning in a solution of H 2 SO 4 :H 2 O 2 (3:1) for fifteen minutes. A five minute rinse in deionized water then precedes etching with a 5% HF solution. The substrates are blown dry using dry nitrogen and placed in a vacuum chamber. The chamber is pumped to a base pressure of 1-2×10 −6 Torr. The substrate is heated to 750 to 800° C. for half an hour to grow the microcrystalline SiC film.
In some embodiments, silicon is employed as the material 204 in the step 186 . Methods for depositing high quality polycrystalline films of silicon on silicon dioxide substrates are given in “Growth of Polycrystalline Silicon at low Temperature on Hydrogenated Microcrystalline Silicon (μc-Si:H) Seed Layer” by Parks et al., Proceedings of the 1997 MRS Spring Symposium, Vol. 467 (1997), pp. 403-408, “Novel Plasma Control Method in PECVD for Preparing Microcrystalline Silicon” by Nishimiya et al., Proceedings of the 1997 MRS Spring Symposium, Vol. 467 (1997), pp. 397-401 and “Low Temperature (450° C.) Poly-Si Thin Film Deposition on SiO 2 and Glass Using a Microcrystalline-Si Seed Layer” by D. M. Wolfe et al., Proceedings of the 1997 MRS Spring Symposium, Vol. 472 (1997), pp. 427-432. A process providing grain sizes of about 4 nm is described in “Amorphous and Microcrystalline Silicon Deposited by Low-Power Electron-Cyclotron Resonance Plasma-Enhanced Chemical-Vapor Deposition” by J. P. Conde et al., Jap. Jour. Of Appl. Phys., Part I, Vol. 36, No. 1A (June 1997), pp. 38-49. Deposition conditions favoring small grain sizes for microcrystalline silicon include high hydrogen dilution, low temperature, low deposition pressure and low source-to-substrate separation.
In a step 188 , the portion of the materials 204 deposited in the step 20 186 that are located on the silicon surface are effectively removed. In one embodiment, in the step 188 , the portion of the materials 204 deposited in the step 186 that are located on the surface of the silicon body 98 are oxidized to provide a structure as illustrated in FIG. 9 D. The step 188 proceeds until the material 204 on the surface is completely oxidized but does not proceed for long enough to oxidize all of the material 204 in the pores 202 . As a result, isolated islands 26 of semiconductor material 204 surrounded by silicon dioxide 100 are formed in the pores 202 in the single crystal silicon 98 forming the body 82 of the device 80 (FIGS. 3 A-C).
Significantly, the materials listed in Table I for use in the islands 26 can be oxidized to form silicon dioxide 208 or to form a volatile gas (CO 2 ). As a result, the islands 26 may be isolated from each other by a simple oxidation process that may not require a photolithographic step.
In a step 190 , an optional gate oxide 210 (FIG. 9E) is formed on the silicon surface and on top of the material 204 deposited in the pores 202 . In a step 192 , the gate oxide is patterned using conventional techniques. The process 180 then ends and further fabrication is carried out using conventional processing. An advantage of the process 180 is that it does not rely on very-fine-line lithography for formation of the islands 26 .
Approaches using such fine line lithography are described in “A Room-Temperature Silicon Single-Electron Metal-Oxide-Semiconductor Memory With Nanoscale Floating-Gate and Ultranarrow Channel” by L. Guo et al., Appl. Phys. Lett. 70(7) (Feb. 17, 1997), pp. 850-852 and “Fabrication And Characterization of Room Temperature Silicon Single Electron Memory” by L. Guo et al., J. Vac. Sci. Technol. B 15(6) (November/December 1997), pp. 2840-2843. These devices were fabricated using e-beam lithography and incorporate features having widths as narrow as 25 nanometers. Similarly, devices described in “Room Temperature Operation of Si Single-Electron-Memory with Self-Aligned Floating Dot Gate” (IEDM 1996), pp. 952-954, Appl. Phys. Lett. 70(13) (Mar. 31, 1997), pp. 1742-1744 and “Si Single Electron Tunneling Transistor With Nanoscale Floating Dot Stacked on a Coulomb Island by Self-Aligned Process,” Appl. Phys. Lett. 71(3) (Jul. 21, 1997), pp. 353-355, all by A. Nakajima et al., employ feature sizes as small as 30 nanometers and require much closer alignment between elements than 30 nanometers. Formation of such small feature sizes using electron beam lithography does not presently lend itself to mass production.
It will be appreciated that other techniques for forming the islands 26 (FIG. 3C) may be employed. For example, shallow implantation of relatively high doses (e.g., ca. 5-50×10 14 /cm 2 ) of silicon or germanium at relatively low energies (e.g., ca. 20 keV) into relatively thin (e.g., ca. 5-20 or more nanometers) silicon dioxide layers, followed by annealing, provides nanocrystals of the implanted species that are insulated from each other and from an underlying silicon region, as described in “Fast and Long Retention-Time Nano-Crystal Memory” by H. Hanafi et al., IEEE Trans. El. Dev., Vol. 43, No. 9 (September 1996), pp. 1553-1558. Performance of memories using nanocrystals in proximity to a channel is discussed in “Single Charge and Confinement Effects in Nano-Crystal Memories” by S. Tiwari et al., Appl. Phys. Lett. 69(9) (Aug. 26, 1996), pp. 1232-1234.
FIG. 10 is a simplified block diagram of a portion of a computer system 220 including the memory device 80 of FIGS. 3A-C, in accordance with embodiments of the present invention. The computer system 220 includes a central processing unit 222 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. The central processing unit 222 is coupled via a bus 224 to a memory 226 , a user input interface 228 , such as a keyboard or a mouse, and a display 230 . The memory 226 may or may not include a memory management module (not illustrated) and does include ROM for storing instructions providing an operating system and read-write memory for temporary storage of data. The processor 222 operates on data from the memory 226 in response to input data from the user input interface 228 and displays results on the display 230 . The processor 222 also stores data in the read-write portion of the memory 226 . The integrated circuit 72 (FIG. 3A) is particularly useful when it is a memory integrated circuit in the read-write memory portion of the memory 226 , because it may then allow the memory 226 to provide increased information storage capacity and/or density.
The embodiments of the present invention provide a compact, sensitive memory cell and permit very high storage capacity memories to be fabricated. Additionally, the inventive memory cell does not require high resolution lithography for fabrication of the islands that store charge.
It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, and yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims. | A memory device includes a plurality of cells, each having a first electrode coupled to a first location on semiconductor material, a second electrode coupled to a second location disposed away from the first location on the semiconductor material and a plurality of islands of semiconductor material. The islands have a maximum dimension of three to five nanometers and are surrounded by an insulator having a thickness of between five and twenty nanometers. The islands and the surrounding insulator are formed in pores extending into the semiconductor material between the first and second electrodes. As a result, the memory cells are able to provide consistent, externally observable changes in response to the presence or absence of a single electron on the island. | 8 |
RELATED APPLICATION
[0001] This application incorporates by reference application titled “Installation of Internally preloaded Opposing Conical Elastomeric Bearing” invented by Neal Muylaert; attorney docket BOEI-1-1006.
FIELD OF THE INVENTION
[0002] This invention relates generally to elastomeric bearings and specifically to opposed internally pre-loaded conical elastomeric bearings.
BACKGROUND OF THE INVENTION
[0003] A key component of a helicopter is the main rotor hub. It provides attachment of the main rotor blades during operation. Rotational power is delivered to the main rotor hub to provide rotational velocity to the blades in order to create aerodynamic lift. The main rotor hub must allow for rotational motion of the blades in the vertical (flap), horizontal (lead-lag), and axial (pitch) directions near the blade root attachment with the hub to accommodate flight control authority and dynamic stability. Main rotor hub systems that accommodate these motions with discrete hinge mechanisms are referred to as fully articulated hubs. Through out the history of the helicopter, engineers have struggled to provide these rotational freedoms with bearing systems that can accommodate high frequency and high amplitude oscillatory motion under high trust loading created by the centrifugal force of the rotating blades. Elastomeric bearings have become an industry standard for accommodating flap-wise motion in articulated hub systems. These bearings are composed of elastomeric material that allows for shear compliance within the elastomer, and for rotational freedom while reacting radial centrifugal force in compression.
[0004] Elastomeric conical bearings are commonly used in bearing assemblies for helicopter rotor systems to accommodate rotor motion. The bearing assemblies are axially preloaded to prevent the conical bearing elements from experiencing a resultant tensional load. Currently, mono-directional bearing elements are employed at each attachment site of the main rotor hub. FIG. 1 depicts a view of a prior art articulated hub assembly 20 a . The hub assembly 20 a includes a tire bar 26 connected to a hub center body 22 . The tie bar 26 is connected to the center body 22 in a similar manner as disclosed in FIG. 1, however, the bearing assembly 30 a is substantially different. The bearing assembly 30 includes a pair of conical bearing elements 52 contacting the journal 28 on the bearing's inner surface 52 and the outer bearing surface is contained within an outer housing 42 a . Each bearing element is a mono-directional single conical taper bearing having an elastomeric element 54 contained within. The conical bearings are arranged such that the apex of the conical elements extends radially outward from one another. The bearing arrangement yields a force couple that extends from one bearing to the other. The force couple yields a bearing pre-load path 43 extending through the hub center body 22 .
[0005] The prior art design creates an extended force couple resulting in a bearing pre-load path extending through the main rotor hub center body. The hub center body must be designed to carry the extra loading. The extra design requirements add weight to the overall rotor hub reducing the aircraft's load capacity and fuel efficiency.
SUMMARY OF THE INVENTION
[0006] The invention provides a weight-reducing bearing assembly for rotary aircraft. An opposed tapered conical elastomeric flap bearing assembly for rotary aircraft includes an outer housing having an outer surface and an inner surface. The outer surface is configured to mechanically connect the bearing assembly to the attachment sections of the hub center body. The inner surface is configured to receive a pair of opposed taper conical bearing elements. An inboard bearing element and an outboard bearing element are located within the outer housing. The bearing elements are arranged in an opposed manner. An axial pre-load can be applied to the opposed bearing assembly wherein the resulting force couple bearing pre-load path is maintained entirely within the bearing assembly. Consequently, the weight of the main rotor hub is reduced increasing the efficiency of rotary flight.
[0007] The proposed invention provides a unique flap bearing arrangement by localizing the pre-load within each flap bearing assembly and, thus, eliminates the necessity for the transfer of the pre-load through the hub structure. The elimination of bearing pre-load through the hub structure can significantly reduce weight of the rotor hub assembly. Many components, including the bearing attachment flanges on the hub center body as well as the bearing housings can be configured to accommodate only the design flight and static loads without having to carry the off axis bearing pre-loads. The unique design of the instant invention yields an approximate 6%-10% weight reduction in the main rotor hub assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
[0009] [0009]FIG. 1 is a partially sectional isolated plan view of a prior art bearing assembly;
[0010] [0010]FIG. 2 is an isometric view of an articulated hub assembly;
[0011] [0011]FIG. 3 is a partially sectional isolated plan view of a bearing assembly of the instant invention;
[0012] [0012]FIG. 4 is an exploded isometric view of the bearing assembly;
[0013] [0013]FIG. 5 is an isometric view of the bearing assembly;
[0014] [0014]FIG. 6 is an alternative isometric view of the bearing assembly;
[0015] [0015]FIG. 7 is a partial sectional view of the bearing assembly; and
[0016] [0016]FIG. 8 is a partial sectional view of the bearing assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0017] [0017]FIG. 2 depicts a fully articulated hub assembly 20 that includes a pre-loaded, opposed flap bearing assembly 30 that maintains a force couple bearing pre-load path entirely within the flat bearing assembly 30 . The hub assembly 20 includes a plurality of rotor assemblies 24 radially attached to a hub center body 22 . The articulated hub assembly 20 is designed to allow and to control the flap, pitch and lead-lag motion of an aircraft rotor.
[0018] In a presently preferred embodiment, the rotor assembly 24 includes a tie bar 26 . However, any other rotor attachment structure or assembly is considered within the scope of the invention. The tie bar 26 is a substantially cylindrical shaped element having a pair of radially opposed journals 28 at an end. Each journal is designed to receive the flap bearing assembly 30 . The bearing assembly 30 extends over the journal 28 attaching itself to the journal 28 . The tie bar 26 and bearing assembly 30 combination attach the rotor assembly 24 to the hub center body 22 .
[0019] The flap bearing assembly 30 includes an inboard bearing element 32 and an outboard bearing element 34 contained within an outer housing 42 to form the bearing assembly 30 . The outer surface of the outer housing 42 is configured to attach the bearing assembly to another structure, for example, the main rotor hub 22 . In a presently preferred embodiment, the outer housing 42 includes two pair of radially extending bearing flanges 36 configured to mate with a hub yolk 38 of the hub center body 22 . However, any other structure or arrangement for attaching the bearing assembly to the rotor hub located on the outer housing 42 is considered within the scope of this invention, for example, a single pair of projections or molding the outer housing to the hub. A plurality of flange bores 60 align with yolk bores 40 allowing fasteners (not shown) to rigidly attach the structures.
[0020] [0020]FIG. 3 depicts an isolated view of the hub assembly 20 b of the instant invention. The tie bar 26 is attached to the hub assembly 20 b via a pair of bearing assemblies 30 b attached to the hub yolk 22 by attachment lug 58 . The bearing assemblies 30 b extend over and contact each respective journal 28 . Each bearing assembly 30 includes a mated set of opposed, taper conical elastomeric bearing elements, 32 and 34 , enclosed within an outer housing 42 b . When preloaded in the axial direction, the opposed bearing assembly 30 b limits the force couple to each individual bearing assembly 30 b . According to the invention, the force couple is not passed through the hub center body. The force couple yields a bearing pre-load path 43 b that remains entirely within each respective bearing assembly 30 b.
[0021] [0021]FIG. 4 depicts an exploded view of the flap bearing assembly 30 b . The bearing assembly 30 includes an outboard bearing element 34 and an inboard bearing element 32 disposed within an outer housing 42 b . The outer housing 42 includes a first section 45 and a second section 47 .
[0022] The first section 45 includes a pair of radially extending flange sections 36 . The flange sections 36 are configured to align with the hub yolk 38 (FIG. 1). An inner surface of the first section is shaped to receive the inboard bearing element 32 . More specifically, an outer surface of the inboard bearing element 32 is bonded to the inner surface of the outer housing 42 b in the first section 45 . The bonding method is suitably any commonly known bonding method used in the art.
[0023] Disposed inside and adjacent the outer surface of the inboard bearing element 32 is an elastomeric element 54 . The composition of the elastomeric element 54 can be any of the commonly employed elastomeric compositions, and is variable based upon the loading requirements of the employment environment. For example, an elastomeric element with a plurality of metal laminates is considered within the scope of this invention.
[0024] Positioned on an inner surface of the elastomeric element 54 is an inner race of the inboard bearing element 62 . The inner race 62 includes a distal section 63 and a proximal section 65 . The outer surface of the inner race 62 is tapered in the direction of the inner bearing element 32 . The inner surface of the proximal section 65 forms an axial bore 44 therethrough. The bore 44 is sized to receive the journal 28 through an open end 55 and extends into the distal section 63 . The axial bore 44 terminates at an inner race closed end plate 53 located in the distal section 63 . An outer surface of the distal section is substantially cylindrically shaped and configured to receive an inner race of the outboard bearing 64 .
[0025] The outboard bearing element 34 is also a taper conical elastomeric bearing wherein the taper is in an opposing direction to the inboard bearing element 32 . The outer surface 66 is configured to bond with the inner surface of the second section 47 of the outer housing 42 b . The inner race has an open end to receive the outer distal section 63 of the inboard bearing inner race 62 . At another end of the inner race of the outboard bearing 64 is an outer plate 56 . Sandwiched between the outer race 66 and inner race 64 is another elastomeric element 54 .
[0026] The outer plate and the inner race closed end plate 63 have a plurality of aligned bores extending therethrough. A tie bar attachment bore 46 is centrally disposed through each to receive a tie bar attachment lug (not shown). The tie bar attachment lug maintains the bearing assemblies 30 connection with the tie bar 26 . Further, a plurality of coupler bores 48 area disposed through the respective surfaces. Each coupler bore receives a coupler lug 49 (FIG. 6) to maintain the spatial integrity between the inboard and outboard bearing elements. Further, a plurality of dowel bores extend through the respective plates, each bore receiving alignment dowels (not shown) extending from the journal end 29 (FIG. 1).
[0027] [0027]FIG. 5 depicts an assembled view of the flap bearing assembly 30 . The inboard bearing element 32 and the outboard bearing element 34 are coupled via a friction fit between the respective elements and the bearing coupler lugs 49 . More specifically, the inner race of the outboard bearing 64 and the inner race of the inboard bearing 62 are frictionally mated upon insertion of the outboard bearing element 34 . Additionally, the outer race of the outboard bearing 66 is bonded to the inner surface of the outer housing 42 . Consequently, the outer housing 42 encompasses both the inboard bearing element and the outboard bearing in a single unitary assembly.
[0028] [0028]FIG. 6 depicts the assembled flap bearing assembly 30 . The bearing assembly includes an outer housing 42 surrounding the inner and outer bearing elements 32 and 34 . The outboard bearing assembly 34 is pressure fit into the inboard bearing element 32 and then bonded between the outer race of the outboard baring 66 and an inner surface of the inboard bearing.
[0029] As discussed above, bearing coupler lugs 49 are disposed through the bearing coupler bores 48 connecting the outboard bearing element to the inboard bearing element. Additionally, a tie bar attachment bore is axially located through the respective bearing elements and is in alignment with a respective bore in the journal end 29 (see FIG. 1). An attachment lug 58 (not shown) is disposed through the tie bar attachment bore 46 and mechanically fastened to the journal end 29 . Consequently, a bearing integrity redundancy is created by to the two separate coupling structures.
[0030] The bearing assembly 30 is axially pre-loaded. In the preferred embodiment, a bearing assembly 30 axial pre-load of 8500-15,000 lb. range is desired. The pre-load helps to prevent the elastomeric elements of the bearing assembly 30 from tensional loading during operating conditions. However, any other pre-load is considered within the scope of this invention. The axial pre-load can be applied through the coupler lugs 49 , the tie bar attachment lug (not shown) or combinations thereof.
[0031] [0031]FIGS. 7 and 8 depict an isolated view of the opposed conical elastomeric bearings with and without pre-loading, FIG. 7, and with pre-loading, FIG. 8. A bearing gap 82 is located between the respective inboard and outboard bearing elements, 32 and 34 respectfully, prior to any axial pre-loading. As the axial pre-load is applied the bearing elements, 32 and 34 , are brought together. The inner races, 62 and 64 , frictionally engage one another and any space, or bearing gap 82 , between the bearing elements, 32 and 34 is removed. The bearing elements, 32 and 34 , combine within the bearing assembly 30 to carry the flap-wise motion of the rotor assembly 24 .
[0032] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. | The invention provides a weight-reducing bearing assembly for rotary aircraft. An opposed tapered conical elastomeric flap bearing assembly for rotary aircraft includes an outer housing having an outer surface and an inner surface. The outer surface is configured to mechanically connect the bearing assembly to the attachment sections of the hub center body. The inner surface is configured to receive a pair of opposed taper conical bearing elements. An inboard bearing element and an outboard bearing element are located within the outer housing. The bearing elements are arranged in an opposed manner. An axial pre-load can be applied to the opposed bearing assembly wherein the resulting force couple bearing pre-load path is maintained entirely within the bearing assembly. Consequently, the weight of the main rotor hub is reduced increasing the efficiency of rotary flight. | 5 |
FIELD OF THE INVENTION
This invention addresses itself to the field of reinforcing ground by means of devices known collectively as rock bolts or, in many underground mining applications, as roof bolts, and specifically to those rock or roof bolts which are fastened in place by grouting a portion of their length or their full length in place.
BACKGROUND OF THE INVENTION
Roof bolting is used as the primary means of roof support in underground mines using the room and pillar mining method, currently between 85% and 90% of U.S. underground coal mines.
The invention pertains to those roof bolts which are grouted in place, either along their entire length or along a portion of their length. In this application of roof bolting, typically four to six foot deep, one inch diameter holes are drilled in the overlying rock strata. These holes are typically spaced on a four foot square grid. Sausage shaped cartridges are inserted in these holes, often temporarily held in place by plastic wedges or caps. The cartridges contain the components of the grout. The grout is normally separated in two portions which, when mixed together, cause the grout to solidify in a competent mass. In the popular polyester resin grout, one of the two portions of the grout contains primarily a thermoset monomer, which is extended with fillers; the other of the two portions contains a catalyst. The two portions are separated in the cartridge by a longitudinal membrane. In a more recent innovation, the two portions are gypsum powder and water, the water being held in separation from the gypsum by encapsulation in 1/16 inch diameter wax containers, which are dispersed through the gypsum in the correct proportion for solidification after mixing. After the cartridges are placed in a previously drilled hole in the mine roof, subsequent insertion of the reinforcing roof bolt, usually a deformed steel bar, with a bolt head and roof plate at the lower end, ruptures the separating membrane or the wax pellets, as well as the wrapping material which forms the cartridge, thus initiating contact between the two components of the grout and spilling the grout in the annular space between the roof bolt and the rock wall of the hole. The roof bolt is rotated for a short period of time to promote mixing of the two portions of the grout. The rotating action also heats the grout, further promoting a rapid cure. After a brief interval, rotation of the bolt is stopped and the bolt is held in position for a period of sufficient duration, typically somewhere between 20 seconds and a minute, for the grout to cure sufficiently to prevent the bolt from falling out of the roof, if the bolt is no longer held.
PROBLEMS WITH CURRENT PRACTICE
Although satisfactory results have been experienced in applying the grouted bolt method of roof support, several problems do commonly occur, and this invention intends to provide the means to solve such problems.
The problems mentioned all have to do with the grouted bolt installation procedure or method, which in turn is limited in effectiveness by the devices available to accomplish such installation. All of the problems referred to result in practice in lack of certainty about the soundness and performance of any given individual roof bolt. To appreciate the potential seriousness of this flaw, consider the fact that wherever a bolt is not properly grouted or the grout has not cured properly, the bolt may, for purposes of contribution to roof reinforcement, be considered absent or removed. Since the roofbolts are normally installed on equal spacings, removing a bolt in this way doubles the unsupported span of the roof structure. If this is done in a conventional beam, stresses in the beam are quadrupled. It is then only a matter of time, as mining advances, for a randomly "absent" bolt to coincide with a local weakness in the roof structure and trigger a roof fall. An analysis of the situation just described allows a breakdown of the operation of installing grouted roof bolts into specific problem areas, which can then be individually addressed for solution.
One problem is associated with the wrapping material which forms the grout cartridge: when the roof bolt ruptures the wrapping material, sometimes the rupture is incomplete, producing what is commonly referred to by the descriptive phrase "the finger in glove effect". When this happens, even when the grout cures completely and properly, the reinforcing strength of the roof bolt is severely compromised by the fact that the grout is totally surrounded and separated from the rock by the wrapping material. This problem is virtually eliminated if the roof bolt is slowly rotated as it is driven up through the grout package. Such slow rotation, however, is difficult to control on a conventional roof bolting machine.
A second problem is associated with the mixing phase of the roof bolt installation operation. During the mixing phase, the roof bolt must be rotated rapidly until mixing is complete. In the typical case, mixing may have to be performed for 15 or sometimes 20 seconds. With certain new fast curing resins, the necessary mix time may be less than 10 seconds. Completeness of subsequent cure of the grout at all locations within the grout is highly dependent upon sufficient mixing. Excessive mixing, on the other hand, results in the destruction of chemical links already formed within the grout structure. Since such broken links do not repair themselves afterward, excessive mixing can easily result in substantial detraction from the final strength of the installation. In present practice, it is left to the roof bolter operator to stop the mixing rotation manually at the proper moment for each individual bolt. Mental judgement of elapsed time is the controlling technique normally used by the operator. The necessary split-second timing simply cannot be achieved this way. Moreover, actual optimum mixing time is not constant to begin with, but is influenced by factors such as the age and condition of the grout packages, as well as by the ambient temperature. Another problem connected with the mixing phase is the fact that it is highly desirable to maintain thrust exerted on the bolt head at a very low value during the high speed mix rotation, to avoid excessive heat generation at the bolt head. The Mine Safety and Health Administration of the Department of Labor has reported incidents where the grout mixture was actually ignited from the heat generated through excessive thrust as just described. Such combustion would be highly undesirable in the already hazardous environment of a coal mine. During the initial insertion of the roof bolt into and along the grout package, it is necessary to exert high thrust (frequently exceeding 2000 lbs, although it should be recognized that rapid bolt insertion even at 2000 lbs can create hydraulic pressures within the liquid grout as high as 5000 psi; the higher the hydraulic pressure at this stage, the higher the probability of resultant damage to the roof structure and/or loss of grout through cracks and crevices in the roof structure: it is therefore necessary to exert careful control over insertion thrust as well as over bolt insertion travel rate) to be able to penetrate the grout mass. On the conventional bolting machine it is not feasible to exert manual control to the extent that thrust can be varied from a high value to a controlled low value. Therefore, to avoid the problem described above with high thrust on the bolt head during mixing, the bolt penetration movement is often halted by the operator a few inches before the bolt head and roof plate have reached the roof line. At this point the operator initiates high speed mixing. When he thinks sufficient mixing has taken place, the operator again applies high thrust to drive the bolt the rest of the way into the roof. The attendant problem is that such extreme axial movement (an inch or more) is virtually certain to sever any chemical bonds which may have formed at that time. An illustration of the fact that chemical bonds have normally formed at the time described is the not infrequent occurrence when it is not possible for the roof bolting machine to provide enough thrust at the conclusion of the mixing phase to drive the bolt all the way into the roof, with the result that the roof plate is left dangling loose from the extended bolt; this is another safety hazard.
Another common problem is control of the duration of the cure period. After completion of the mixing phase, the bolt is held in support by exerting a high thrust to the bolt head and the roof with the bolting machine, without rotation, for a period of time which is long enough to permit sufficient grout curing to avoid roof movement when the thrust and the bolting machine are removed. The high thrust applied during this period also acts to minimize any bad separations within the roof strata which may be occurring. In present practice, the time the bolt is held in support by the machine is again controlled by the operator, and may be anything from 15 seconds to several minutes. On the average, the unavoidable result is excessive dwell time, which affects productivity. Since the roof bolting operation is usually the pacing element in the coal mining production cycle, such productivity decrease is potentially very serious in its effect upon profitability.
Another common problem arises from the fact that once the grouted bolt is installed, there is no simple way to test if it is sound. As is seen from the foregoing discussion, it can easily happen that some bolts do not have properly mixed or cured grout or that the grout packaging material is coincidentally disposed within or around the grout in such a manner as to interfere with the desired rock reinforcing function of the bolt.
The conventional test of applying a test torque to the roof or rock bolt head is relatively meaningless, since, if applied after the roof bolting machine has been removed from the bolt head, so that significant curing of the grout has taken place, the test can only indicate or disclose those bolts which are practically totally loose. To appreciate this fact, consider the following:
A typical grade 60 deformed steel roof bolt yields at a stress of 60,000 psi in tension, or approximately 30,000 psi in shear. The popular no. 6, or 3/4 inch diameter roof bolt therefore yields at a torsional load of 207 lbft. The maximum test torque which can be applied must stay well below this value of 207 lbft. Equivalent bond shear strengths at the steel-grout interface reported by the industry are as high as 700 psi within fifteen minutes after mixing of the grout. The maximum grouted length which could be tested on a no. 6 bolt without twisting the bolt head on the body, is therefore less than four inches. In other words, if the lower four inches of the roof bolt are properly grouted and fully cured, the entire remaining length could be totally devoid of grout and yet the bolt head would yield in torsion, rather than show a defect in the grout.
The U.S. Bureau of Mines has recognized this problem by funding research on a roof bolt bond tester--cf. Bureau of Mines Technology News No. 128, January 1982. Although in principle the effort is commendable, the device performs its test in a separate operation, after the production bolting is completed. What is still lacking is a means of indicating quality of the grouting during the installation process, before temporary supports are removed from the roof.
In view of all the foregoing problems, it should be not surprising that as a result of tests performed in Canadian and Swedish mines, using a Swedish ultra sonic testing device, the conclusion was drawn that 20% to 40% of installed bolts were of insufficient grouting to be classified as safe.
In a recent innovation, the reinforcing action of full length grouted rock bolts has been improved by adding tension which is imposed upon the bolt during installation. To accomplish this, the grout is confined to the upper portion of the bolt by means of a sealing washer. The grout is mixed and cured as described before for the full length grouted bolt. The remaining length of bolt which has not been encased in grout contains a threaded connection which is subsequently tightened by the bolting machine to obtain the desired bolt tension. Since desired bolt tensions are normally in the range of 8000 to 10,000 lbs, it will be appreciated that an extremely quick-setting grout is called for in this application. Because of the concomitantly short reaction times associated with such quick-setting grout, all of the problems listed above are then further exacerbated.
OBJECTS OF THE INVENTION
This invention is accordingly directed to novel means and novel methods to install grouted rock bolts while eliminating or substantially reducing the common difficulties just described. A principal object of the invention is to increase mine safety by ensuring dependable mine roof support when using grouted rock bolts. An additional object of the invention is to increase mining productivity by minimizing the time required to install each grouted rock bolt, without compromising the quality of the installation. A further additional object of the invention is to improve safety and speed of grouted rock bolt applications by providing automatic controls which ensure proper mixing and proper curing of the grout, while minimizing the time involvement of installation machinery. A further additional object of the invention is to improve safety of grouted rock bolt applications by providing method and means to conduct a meaningful test on each rock bolt installed, as part of the bolt installation cycle; said test to provide a simple indication that proper mixing and proper curing of the grout have taken place.
Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing description thereof. Similarly, it will become apparent from the detailed description of the invention, that useful application is not limited to underground roof bolting. Examples of additional fields of application include, but are not limited to, the anchoring of machinery or other structures to prior existing masonry, rock or rock-like masses. It should be noted that throughout this Specification, the terms "rock bolt" and "roof bolt" are used interchangeably. It should be similarly understood that the invention pertains to all grouted rock bolts, even though application of the invention to roof bolts may be of the greatest immediate interest.
SUMMARY OF THE INVENTION
The means and methods for controlling the installation parameters of a grouted rock bolt or roof bolt according to the invention, may be visualized as consisting of four parts:
means and method to insure proper bolt insertion in such a manner as to maximize shredding of the grout packaging material and to minimize migration of the grout away from its intended location, i.e. the previously drilled bolt hole;
means and method to insure proper mixing of the grout;
means of controlling the time that high thrust is applied to the surface of the rock mass to be reinforced while the grout is curing and increasing in strength;
means and method to apply a simple test to the grouted rock bolt, within its total installation cycle, to prove final reliability of that rock bolt.
The invention also makes it possible to integrate some or all of the four parts as just described in a single machine which then provides the capability to routinely remove or at least substantially reduce the hazard of malfunction at random of a portion of the roof bolt population installed.
The mentioned means and method to control the roof bolt insertion process becomes the first step in the bolt installation cycle as follows: when the roof bolting machine operator initiates the bolt installation process by suitable action such as the pushing of a button or the flipping of a toggle lever or switch means, after having first drilled a suitable hole in the rock mass to be reinforced, and after having first also inserted the grout cartridge or cartridges into a previously drilled hole in the rock mass to be reinforced, as well as after having first guided the roof bolt a short distance into said drilled hole, and having first connected the other end or head of the roof bolt to a bolt driving means on the roof bolting machine, the following actions are automatically caused to take place by the roof bolting machine:
The bolt is steadily pushed into mentioned drilled hole while penetrating the previously positioned grout cartridge. At the same time, a slow (approximately 60 RPM has been found to be a good choice in practice) rotation is applied to the bolt. As the bolt penetrates a greater distance into said drilled hole, the thrust which must be exerted on the bolt to maintain the steady penetrating movement as described increases. When the thrust as just described attains a threshold value which has been previously determined to be adequate to achieve full insertion, and yet not so high as to cause loss or migration of the grout as described above (a thrust of 2000 lbs or 2500 lbs has been found to be a good choice in practice), a thrust threshold sensing means switches a thrust controlling means to cause the amount of thrust applied to achieve insertion motion, to decrease to a value much lower than the threshold value just mentioned (a good choice for said lower thrust value has been found to be approximately 200 lbs); at the same time the mentioned thrust threshold sensing means switches a speed controlling means to cause the rotation rate of the roof bolt to increase to a set higher value (400 to 500 RPM has been found to be a good range in practice). The lower thrust value and higher rotation speed value are necessary for the next step in the bolt installation process as will be described in due time. It has been found that on occasion the thrust required during insertion may rise to the mentioned threshold value before the bolt is quite completely all the way inserted into the drilled hole. When this happens, however, the bolt travels the remaining distance to full insertion during the initial part of the next step, as will be described.
The means and method to insure proper mixing of the grout become the next step in the bolt installation cycle. The thrust controlling means and the rotation speed controlling means described in the previous bolt installation step are used to maintain the thrust and rotation speed at suitable low and high values (e.g. 200 lbs and 450 RPM), respectively. The low thrust is necessary to avoid excessive friction between the bolt head and the roof plate as was discussed in the section describing Problems with Current Practice. The high rotation speed is necessary to achieve rapid and thorough mixing of the grout. During the initial phase of the mixing process, the high rotation speed raises the temperature of the grout. This increase in temperature does not only accelerate the subsequent process of curing the grout, but first reduces the effective viscosity of the mixture, so that under the combined influence of the high rotation speed and low thrust, the bolt is readily driven up into the drilled hole any remaining distance possibly left after the previous high thrust insertion step, as described above. It is not feasible to delete the high thrust, low speed insertion step prior to activation of the low thrust, high speed mixing step for two reasons:
1. Initiating insertion at high rotation speed would introduce a very real danger of the bolt bending or flying loose.
2. Initiating high rotation speed when the bolt is still substantially protruding from the drilled hole introduces substantial differences in degree of mixing achieved between upper and lower ends of the bolt. The least amount of mixing would take place at the far end of the drilled hole, where the quality of grouting is the most critical.
The invention provides for two methods and means to achieve proper grout mixing, without continuing the mixing action longer than necessary. The first method involves the initiation of an automatic timer means, such initiation being precipitated by achieving the high thrust threshold at the conclusion of the bolt insertion step as described before. The automatic timer means then allows the low thrust and high speed mixing action to continue until a set time period has elapsed, such time period previously determined to be optimum to achieve proper mixing, on the average, for the grout under the circumstances under which such grout is installed. When said time period has elapsed, said timer means then causes the thrust applied to the head of the bolt to again increase to a high value while said timer means simultaneously stops any subsequent bolt rotation. It has been found that a suitable value exists for the high thrust value just mentioned, appropriate for the next step in the installation process: the step of providing for grout curing. In the typical case, values substantially in excess of optimum high thrust at this stage may crush the near surface layers of the rock to be reinforced, and in so doing deteriorate the rock structure. On the other hand, values much lower than the determined optimum may permit bed separations which may have developed in the rock strata to persist to a much greater degree, and thus detract from the competence otherwise attainable in the reinforced rock structure. The optimum value for the high thrust just discussed has been found to lie in the range of 2000 to 8000 lbs, depending primarily on the lithology of the rock strata involved. The second (and probably preferred) method to ensure proper duration of the mixing action according to the invention, involves the continuous monitoring of the torque required to drive the roof bolt in high speed rotation. Such torque needed to rotate the roof bolt has been found to rise sharply when the grout begins its initial set. As soon as sufficient torque rise is measured during the mixing step as described, mixing is completed and the torque monitoring means causes the rotation controlling means to stop rotation of the roof bolt. The value of torque which is indicative of completion of the mixing step varies to some degree with the length of the roof bolt employed, as well as with the type of resin employed. In the typical case using a five foot long roof bolt, a torque value of 70 lbft has been found practical. We have also found that due to inertial effects in a practical machine, the apparent torque measured may briefly rise to a value in excess of the torque value predetermined to be suitable to indicate completion of the mixing cycle (such as p. e. the value of 70 lbft mentioned above), immediately upon initiation of high speed rotation. To avoid the possibility of such initial high torque transient causing premature indication of completion of the mixing step, the output from the torque monitoring means is briefly suppressed immediately after initiation of high speed rotation.
It will be appreciated that it is necessary during such torque monitored mixing to ensure that thrust exerted to the roof bolt head is controlled to a suitably low and constant value, so that the torque measurement as described is truly indicative of the degree of mixing achieved within the grout, and not indicative of a variation of friction under the bolt head instead. Such constant low thrust control is provided as part of the roof bolt installation means as already described above, where it was discussed in connection with the need to avoid generating excessively high temperatures at the roof bolt head, as well as with the need to provide the capability to, in some cases, move the roof bolt a short distance further into the drilled hole as described, during the initial portion of the high speed rotation mixing cycle. When said torque measuring means has sensed that the grout mixing has been completed, the torque measuring means then causes the thrust applied to the head of the bolt to again increase to a high value while simultaneously causing the stopping of any subsequent bolt rotation, in the same fashion as described before for the case where a timer means was used to control the duration of the grout mixing cycle.
The means to insure sufficient curing of the grout prior to removal of the installation (and in the case of roof bolting: roof supporting) machinery, according to the invention, becomes the next step in the bolt installation cycle. The indication of completion of proper grout mixing obtained in the previous step of the bolt installation process either from timer means or from torque measurement means as described above, not only causes the cessation of bolt rotation and the increase of thrust applied to the bolt head to a predetermined high value as already discussed, but also causes initiation of a cure cycle timing means, separate and distinct from a mixing cycle timing means which might in some cases also be employed as discussed above. The cure cycle timing means thus begins timing and after a set time period has elapsed, predetermined to be sufficient and yet not excessive to attain sufficient strength within the grout to allow removal of the bolt installation machinery as described, the cure timer causes a visible or audible signal to be emitted. The roof bolting machine operator then has no doubt about when it will be safe and acceptable to move to the next bolt installation location.
The invention further provides the opportunity to include an additional installation step, which is valuable in connection with roof bolts which are not grouted along their full length, but only for a distance from their far end, their ungrouted portion to be tensioned after sufficient grout curing has taken place. These tensioned bolts were referred to above in the description of Problems with Current Practice and are generally known as "point anchor grouted bolts". When using such point anchor grouted bolts, the cure cycle timer means previously described, instead of causing a visible or audible signal to be emitted, first causes the following actions to be implemented in sequence, in mentioned additional installation step:
a--The thrust controlling means described earlier causes the thrust exerted on the roof bolt head to decrease from the high value described before for the grout cure cycle to a low constant value (the same value as was used before during the grout mixing cycle, p. e. 200 lbs, is a good value).
b--The rotation controlling means described earlier causes the roof bolt head to be rotated again, at a relatively slow (60 RPM has been found to work well) and constant speed.
c--A torque measuring means monitors the torque required to perform the rotation as described in step b. As the roof bolt is further tightened because of the rotation, it will be appreciated that said torque will increase, since the torque is a function of the tension in the roof bolt.
d--When the torque discussed in step c has risen to a value previously determined to be representative of the tension which is desired in the roof bolt for appropriate stability of the rock to be reinforced, the torque measurement means described in step c causes previously discussed rotation control means to stop any further rotation of the roof bolt head. In an additional implementation of the device to install grouted roof bolts, when rotation of the bolt head has been stopped as just described, a visible or audible indicating means can be caused to give clear indication that the roof bolt installation cycle has been totally completed.
Finally, the invention provides for means and method to apply a simple test to the grouted rock bolt, within its total installation cycle, to prove final reliability of that rock bolt. In the case of installation of a fully grouted roof bolt, said simple test is applied automatically, immediately after the timed grout cure period, which was discussed previously, has elapsed. The method of applying such simple test consists of applying a static test torque to the roof bolt head and relating said test torque to angular movement of the roof bolt head, which angular movement is measured simultaneously with the application of the static test torque mentioned. The timing of the application of mentioned simple test is critical; as was pointed out under the heading of Problems with Current Practice: if said test is applied too late, the grout becomes so strong that the test becomes meaningless; if said test is applied too soon, the grout has not yet cured sufficiently to withstand the test torque applied, even though the grout may be sound otherwise. During these measurements of torque and angular movement of the roof bolt head, thrust exerted on the bolt head is automatically held to a low constant value, in the same manner as it was described before for the final tensioning of a point anchor grouted bolt. For the case of the point anchor grouted bolt, the simple test invented is applied immediately after completion of final tensioning of the point anchor grouted bolt; for this case the simple test consists of applying a static test torque to the bolt head, where the static test torque is preferably equal in value to the torque applied earlier to the roof bolt head in order to obtain the final desired tension. While maintaining said static test torque on the roof bolt head, a standard, timed period (typically a few seconds) is permitted to elapse, during which period an angular deflection measurement means registers the angular movement which has taken place during said timed period. Excessive movement is then indicative of low quality grouting. In a different embodiment, the static test torque applied as described, decreases automatically if the angular movement as described increases to a predetermined value. In such a way the value of static test torque remaining at the conclusion of the described timed test period can serve as an indication of the quality of the grouting of the bolt. It will be appreciated that in most cases the latter version will provide a more sensitive and accurate indication of grouting quality.
In summary, the apparatus for implementing the methods to obtain control of the installation parameters of a grouted roof bolt, as described, in accordance with the invention, includes the following means: means to control thrust exerted on the roof bolt head; means to vary thrust applied to that roof bolt head back and forth from a high value to a low value, in response to a control signal; means to rotate and control rotation rate of said bolt head, means to start and stop rotation of said bolt head, in response to a control signal; and in some embodiments also means to measure and monitor torque applied to cause continuing rotation of said bolt head; in some embodiments also means to measure and monitor torque applied to said bolt head without continuing rotation, as well as means to measure angular movement of said bolt head; and means to relate said angular movement measurement and said torque measurement without continuing rotation in a manner appropriate to obtain visual indication of the adequacy of the cure of the grout of the same roof bolt; means to relate and synchronize in concert, the action of all devices and means as described.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the principles of the invention, as well as certain preferred embodiments of the invention, in which:
FIG. 1 is a diagrammatic representation of the preferred embodiment of the means necessary to install grouted roof bolts according to the invention.
FIG. 2 is a graphical representation of the relationship between rotation rate and time elapsed after the operator of the machine has initiated the automatic bolt installation cycle for a full-length grouted roof bolt.
FIG. 3 is a graphical representation of the relationship between torque applied to the bolt head and time elapsed after the operator of the machine has initiated the automatic bolt installation cycle for a full-length grouted roof bolt.
FIG. 4 is a graphical representation of the relationship between thrust applied to the bolt head and time elapsed after the operator of the machine has initiated the automatic bolt installation cycle for a full-length grouted roof bolt.
FIG. 5 is a graphical representation of the relationship between rotation rate and time elasped after the operator of the machine has initiated the automatic bolt installation cycle for a point anchor grouted roof bolt.
FIG. 6 is a graphical representation of the relationship between torque applied to the bolt head and time elapsed after the operator of the machine has initiated the automatic bolt installation cycle for a point anchor grouted roof bolt.
FIG. 7 is a graphical representation of the relationship between thrust applied to the bolt head and time elapsed after the operator of the machine has initiated the automatic bolt installation cycle for a point anchor grouted roof bolt.
FIG. 8 is a representation of the principle of operation of the preferred embodiment for a torque measurement means capable of measurement of torque dynamically, as well as statistically (i.e., with or without rotation of the roof bolt).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Certain components of the preferred means to accomplish the objects of the invention, have been discussed in detail in several patents which have been issued to me previously: U.S. Pat. Nos. 4,300,397; 4,444,530 and 4,352,600, where such components were used in different combinations and for different purposes. A preferred embodiment of the invention is shown in FIG. 1, where the energy to install a grouted bolt is shown to originate from a Power Source. The Power Source is preferred to be a source of pressurized hydraulic oil, but can be derived in a number of different ways, as anyone skilled in the art of designing machinery will appreciate. The energy from the Power Source is led by a carrier conduit (in our preferred embodiment represented by a flow of pressurized oil through a hose or pipe) to a Power Modulating Means. The latter is, in this embodiment, a hydraulic circuit consisting of hydraulic valves, which are capable of controlling oil flow and oil pressure, in response to signals which are generated as will be described presently. In the preferred embodiment, the signals which control said hydraulic valves are pneumatic, and originate from the Computing Means, also shown in FIG. 1. There are three hydraulic circuits which in final analysis power the roof bolt installation means; these three circuits all derive from and are controlled by the Power Modulating Means, shown in FIG. 1, where those three circuits are indicated, respectively, by the nomenclature THRUST, CARRIER, and MOTOR. Again in the preferred embodiment, the THRUST circuit maintains a controlled hydraulic oil pressure against the lower surface of a sliding piston 1, which is capable of sliding along axis A, in such a manner that thrust is exerted on the roof bolt head 2 to the degree and in the magnitude necessary to accomplish each bolt installation step as described above in the Summary of the Invention. It should be apparent that the amount of sliding or travel of said piston which can be made available within a practical physical structure must be limited. In the preferred embodiment the available distance for such sliding or travel is somewhat less than one inch. The physical device which contains axes A, B and C in FIG. 1, is mounted on and held in position by a conventional arrangement which is not shown in FIG. 1, but which, on some roof bolting machines is known as a "boom", on other roof bolting machines as a "mast". The "boom" or "mast" normally has a lifting mechanism associated with it, which enables the machine to lift mentioned device containing the axes A, B, and C up or down, in contact with or away from the roof bolt. Said lifting mechanism is normally controlled manually by the operator of the roof bolting machine. The invention provides the additional capability to perform described lifting action, up or down, automatically as required while performing any installation sequences according to the invention as described before. Such automatic lifting up or down is accomplished by modulating the power hydraulic line labelled CARRIER in FIG. 1 on up, on down, or off. The control of power (on up, on down, or off, as described) of the CARRIER circuit is arranged in such a way that, whenever the roof bolt installation means is within an installation cycle, i.e., whenever a roof bolt is in the process of being installed, the CARRIER circuit is actuated in such a way that piston 1 is kept within its available travel range as described above. The preferred means to indicate that piston 1 may be in danger of exceeding its available range is two simple limit switch means, which, in the preferred embodiment are pneumatic camroller valves, although other means, such as electric limit switch means would work also. Said limit switch means are not shown in the drawings, but are arranged in such a way that one limit switch means emits a signal when piston 1 is in danger of exceeding its available travel distance in one direction, and the other limit switch means emits a signal when piston 1 is in danger of exceeding its available travel distance in the other direction. The signals emitted as just described then cause the Power Modulating Means to constantly urge the "boom" or "mast" lifting action in the direction appropriate to maintain piston 1 generally in the center portion of its available travel range.
The third hydraulic oil circuit which emanates from the Power Modulating Means, and which is labelled MOTOR, controls the action of the drive motor 3, in FIG. 1. In the preferred embodiment, drive motor 3 is a hydraulic motor. As described before under Summary of the Invention, the action of the drive motor consists of three possible states: on at high speed, on at low speed, and off, since the drive motor 3 is rotationally coupled to rotation output means 4. The signals which cause the Power Modulating Means to change the oil supply to drive motor 3 as required for the bolt installation sequences as described before, are generated in the Computing Means. In the preferred embodiment, drive motor 3 drives a chain 5, which is shown in side view in FIG. 1, and in top view in FIG. 8. Chain 5 causes rotation of shaft 6 in FIG. 1, which in turn drives chain 7, through sprockets as shown. Chain 7, finally, drives cylinder 8 in rotation. Cylinder 8 contains piston 1, which was discussed earlier. Note that in the arrangement described piston 1 is capable of being driven in rotation, as well as of moving axially. To accomplish this dual motion, piston 1 is assembled rotationally rigidly to cylinder 8 by means of a sliding spline means, and for the preferred embodiment, a ball spline means is employed to minimize axial friction between the sliding members described. This particular arrangement is discussed further in my previously issued patent. U.S. Pat. No. 4,300,397. FIG. 8 further shows an advantageous arrangement of the preferred embodiment in which the drive torque transmitted through drive chains 5 and 7, can be measured continuously. Shaft 6 which is co-axial with axis B, is mounted in bearings (not shown) which in turn are fastened to a frame 9. Frame 9 is mounted in such a fashion that it is capable of pivoting around axis A. When the drive motor is called upon to exert a torque in order to drive a torsional load at the roof bolt head, force vectors in the chains 5 and 7 add up in such a way as to cause said pivoting motion of frame 9. Frame 9 is prevented from traveling very far in the described pivoting direction by force measurement means 10 and 11. In the preferred embodiment, force measurement means 10 and 11 are plunger actuated air pressure regulating devices, which can be seen in FIG. 8 to be mounted in such a way that an increasing force exerted by frame 9 in one direction causes the air pressure regulated by force measurement means 10 to increase, and an increasing force exerted by frame 9 in the other direction causes the air pressure regulated by force measurement means 11 to increase. Air pressure output from force measurement means 10 is then representative of and proportional to the torque delivered to the roof bolt head 2, when said roof bolt head is driven in right hand rotation. Force measurement means 11 is used to provide capability of improved sensitivity in a static torque test to a roof bolt at the end of its installation cycle, as will now be described in detail. In the preferred embodiment, a static torque test is performed as follows: drive motor 3 is off and in "free wheeling" mode, then locking means 12, which can be made similar to a conventional clutch or disc brake, and can be actuated hydraulically or pneumatically, locks in such a way that frame 9 and cylinder 8 become in effect one rigid assembly, and relative rotational motion is no longer possible between 9 and 8. It may be appreciated that there exist several alternate locations for locking means 12. Locking means 12, for example can be built around cylinder 8. Alternatively, locking means 12 can be built as part of the assembly which includes shaft 6: it is this alternate location which is shown in FIG. 1. The next event in the sequence of event which makes up the static torque test, is pressurization of cylinder means 13, which then extends its rod 14 and thereby exerts a force on frame 9, causing frame 9 to attempt to pivot around axis A. Since frame 9 and cylinder 8 are now, in effect, one rigid assembly as just described, the pivoting motion about axis A is resisted by the roof bolt 2, which is still coupled to the installation machine. If the roof bolt 2 yields somewhat in rotation, allowing some further extension of rod 14, frame 9 causes the plunger of force measurement means 11 to be depressed. The latter action causes force measurement means 11 to increase its output air pressure, while it returns a reaction force to frame 9 in proportion. An examination of the force balance on frame 9 shows that for any particular and constant value of force exerted by cylinder means 13, the output of force measurement means 11 defines a specific combination of torsional deflection and torsional resistance offered by the roof bolt under test. Under the circumstances described, the higher the output from force measurement means 11, the lower the stiffness, and thereby the strength of the roof bolt. Contemplation of the principles shown in FIG. 8 reveals that many equivalent means exist to obtain the measurement of quality of strength of the grouted roof bolt at a specifically defined time immediately upon installation of that same roof bolt. For example, it would be possible to replace force measurement means 11 with a limit switch means, which indicates when excessive deflection is encountered under the application of a constant test torque to the roof bolt 2, by pressuring cylinder means 13. The exact same multiplicity of arrangements as just described to test the stiffness, and thereby the quality of a fully grouted roof bolt (performed at a specific time soon after the installation of that grouted bolt) can be utilized to apply a test after completion of installation of a point anchor (tensioned) grouted roof bolt. Such a test applied to a point anchor grouted roof bolt would disclose first the torque required to turn the bolthead slightly more, and thereby the tension carried by that bolt. If the test torque applied by pressurization of cylinder 13 is then maintained for a short period of time, observation of possible further movement of frame 9 during such additional period of time, as signaled by force measurement means (or, in another embodiment, limit switch means, as discussed above) 11, would be indicative of insufficient curing of the grouted portion of the point anchor bolt assembly prior to final tensioning of the roof bolt. Any signals generated by force measurement means 10 and 11 at any time during the roof bolt installation cycle are used as input for the Computing Means shown in FIG. 1. As has been mentioned before, the preferred embodiment which has been tested and shown to be reliable in the hostile environment of an underground coal mine, uses pneumatic valves to perform the logic and computations required in the Computing Means. For the same reasons of reliability, pneumatic means is advocated for determination of elapsed time periods necessary as described before in the Summary of the Invention. Such Timing Means are shown in FIG. 1 by a separate block connected to the Computing Means. The Computing Means could clearly also be built using electric or electronic components, in place of the pneumatic components used. In any case it is possible for anyone skilled in the arts to construct the Computing Means, using the information contained in this application as a guide, otherwise using known principles. To additionally clarify, and assist in any design construction of a device according to the invention, FIGS. 2, 3 and 4 show how the installation parameters (respectively, the variation with time of bolthead rotation rate, torque applied to the bolt head, and thrust exerted on the bolt head) for a fully grouted roof bolt relate to the Computing Means and to each other. Similarly, FIGS. 5, 6 and 7 show the same relationship for a point anchor partially grouted (and tensioned) roof bolt.
The provision of means to measure torque delivered by the device to install grouted roof bolts, according to the invention, can be advantageously extended to solve another problem which exists in practice: when the hole is drilled in the rock to receive a rock bolt to be installed, reasonable accuracy in drilling that hole to the proper depth is critical. If the hole is not drilled deep enough, the rock bolt cannot be driven completely in and the roof plate under the rock bolt head is left loose. If the hole is drilled too deep, a substantial fraction of the grout may be lost in filling the extra volume, thus being unavailable where it is needed to perform its reinforcing function: in the space surrounding the rock bolt. In conventional practice, the machine operator watches the drill steel as it advances into the hole and stops drilling when he observes that the steel has entered the hole to the proper length. Because of poor visibility and other factors, actual hole depth is often poorly controlled. It is not immediately feasible to fasten a stop to the drill thrusting mechanism, since the relationship of this mechanism to the surface of the rock varies considerably from hole to hole. It is potentially dangerous to fasten a stop to the drill steel itself, because of the forces involved when such a stop would contact the rock surface at full drilling thrust and rotation rate. It is, however, possible and practical to fasten a small torque generator to the drill steel. Such a torque generator can be nothing more than a hardened collar, with the outside diameter tapered to gradually present more surface to the rock, as it enters the hole being drilled. The necessary maximum diameter of such a torque generator has been found to be no more than twice the diameter of the drill steel used. The torque generator is fastened to the drill steel at the point which enters the rock when the hole being drilled has attained proper depth for the rock bolt to be used. As the tapered exterior of the torque generator is forced into the hole, more surface is in contact with the rock and the torque required to maintain rotation increases. It then becomes a simple matter to arrange for a limit switch means in combination with the torque measurement means already described to give a control signal when the torque being monitored exceeds a predetermined value. Described control signal can then be made to cause emission of a warning signal, as well as automatic halting of the drilling action, by stopping rotation and thrust. It has been found that the combination of devices described to monitor drilling torque and emitting a control signal when a predetermined torque level is exceeded can also be used advantageously in applications in rock bolting where the ground being drilled tends to bind the drill steel from time to time. In such cases, the Computer Means is arranged to stop thrust, or actually slightly withdraw the drill steel from the hole, when a torque rise is signalled as described. Drill rotation for such an application is then not halted, but maintained. As the drill bit then cuts itself free under the no-thrust condition, the torque which is still being monitored, drops down to a much lower value again, which causes the Computer Means to reapply normal drilling thrust and thus resuming normal drilling.
The means and method of installing roof bolts according to the invention, allow improved control over the grout curing process. If desired, the invention also makes it possible, during the production process of installing roof bolts, to identify those grouted bolts which still do not attain a satisfactory cure or bond to the rock to be reinforced. Since the control and testing of the grouted bolts is applied during the installation process of roof bolting, inadequate bolt quality may be identified immediately, while the installation machinery is still in position, so that additional grouted bolts may be installed as a supplement as necessary, before temporary roof support is removed.
It is apparent that the various devices described above can be executed in such a manner that they can be readily inserted in series with an existing roof bolt tightening means, as well as executed so that said devices form an integral part of the roof bolt tightening means.
While I have shown and described several embodiments in accordance with the present invention, it is obvious that the same is not limited thereto, but is susceptible to numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims. | Means and method for improving productivity and quality of grouted rock bolt installations. The invention provides means of automatically installing full length grouted bolts as well as tensioned (point anchor) grouted bolts, which ensures proper shredding of the grout package, proper mixing and proper curing of the grout, and minimizing machine time involvement. The invention also makes it possible to include a test for quality on each grouted bolt installed, within the automatic installation cycle. The invented means further allows control of the depth of holes drilled for rock bolting and automatic freeing of drill steels, where they may be danger of drill steel binding during drilling for rock bolting. | 4 |
RELATED UNITED STATES APPLICATIONS/CLAIM OF PRIORITY
Not applicable.
FIELD OF THE INVENTION
The present invention relates to a system and method for identifying the raw materials consumed in the manufacture of a chemical product.
BACKGROUND OF THE INVENTION
The Internet is a global phenomena that has become an increasingly important platform for the buying and selling of chemicals. In order for entities offering business-to-business trading web sites over the Internet to distinguish themselves from their competitors, they must provide value added services that maximize the potential of the Internet platform. One of the most beneficial tools for sellers operating in the non-personalized environment of the Internet is a method to accurately target their sales efforts to real potential customers instead of the broadcast method currently available on the Internet.
It is very important to a raw material producer or trader to know which products consume a particular chemical as a raw material. Conversely, knowing what raw materials are used to create a chemical product could help a researcher or engineer determine how to manufacture a particular chemical product. The Internet contains global information on companies and the products that they buy and sell. A tool that uses this information to identify the raw materials consumed in the manufacture of a particular chemical products would be valuable to a raw material producer, as well as a chemical product manufacturer.
SUMMARY OF THE INVENTION
The present invention overcomes the aforementioned problems of the prior art by providing a more efficient solution. According to a first aspect of the present invention, a method for identifying chemical products, the manufacturing processes of which consume a certain raw material, is provided. The user enters a name of a raw material. A query is created consisting of the raw material and synonyms of the raw material. The query is compared to a database of companies comprising fields of chemical products manufactured by a company and raw materials purchased by a company. The present invention performs a statistical analysis on a database, and based on the analysis, identifies, within a certain level of confidence, chemical products, the manufacturing processes of which, consume the raw material.
In a second aspect of the present invention, a method for identifying raw materials consumed in the manufacture of a certain chemical product is provided. The user enters a name of a chemical product. A query is created consisting of the chemical product and synonyms of the chemical product. The query is compared to a database of companies comprising fields of chemical products manufactured by a company and raw materials purchased by a company. The present invention performs a statistical analysis on a database, and based on the analysis, identifies, within a certain level of confidence, raw materials that are consumed in the manufacture of a particular chemical product.
In a third aspect of the present invention, a computer-readable medium containing instructions for causing a processor to perform the method for identifying chemical products, the manufacturing processes of which consume a certain raw material, described above is provided.
In a fourth aspect of the present invention, a computer-readable medium containing instructions for causing a processor to perform the method for identifying raw materials that are consumed in the manufacture of a certain chemical product described above is provided.
In a fifth aspect of the present invention, a system for identifying chemical products, the manufacturing processes of which consume a certain raw material, is provided. The system comprises means for performing the method described above.
In a sixth aspect of the present invention, a system for identifying raw materials that are consumed in the manufacture of a certain chemical product is provided. The system comprises means for performing the method described above.
In a seventh aspect of the present invention, a server for identifying chemical products, the manufacturing processes of which consume a certain raw material, is provided. The server comprises memory containing a database of companies and an associated program, and a processor responsive to said program. The processor is configured to perform the method described above.
In an eighth aspect of the present invention, a server for identifying raw materials that are consumed in the manufacture of a certain chemical product is provided. The server comprises memory containing a database of companies and an associated program, and a processor responsive to said program. The processor is configured to perform the method described above.
In a ninth aspect of the present invention, a client machine for identifying chemical products, the manufacturing processes of which consume a certain raw material, is provided. The client machine comprises memory containing a program and a processor responsive to said program. The processor is configured to send a name of a raw material to a server so that the server will perform a statistical analysis according to the method described above. The client machine further comprises a monitor to display the results of said analysis.
And in a tenth aspect of the present invention, a client machine for identifying raw materials that are consumed in the manufacture of a certain chemical product is provided. The client machine comprises memory containing a program and a processor responsive to said program. The processor is configured to send a name of a chemical product to a server so that the server will perform a statistical analysis according to the method described above. The client machine further comprises a monitor to display the results of said analysis.
These and other aspects, features, and advantages of the present invention will become better understood with regard to the following description, claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring briefly to the drawings, embodiments of the present invention will be described with reference to the accompanying drawings in which:
FIG. 1 depicts the hardware configuration of the present invention.
FIG. 2 depicts a flow chart that illustrates the steps related to the method or process of one aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the system configuration, method of operation, and article of manufacture or product, such as a computer-readable medium, for example, a floppy disk, a conventional hard disk, CD-ROM, Flash ROM, nonvolatile ROM, RAM, and any other equivalent computer memory device, generally shown in FIGS. 1-2. It will be appreciated that the system, method of operation, and article of manufacture may vary as to the details of its configuration and operation without departing from the basic concepts disclosed herein. The following detailed description is, therefore, not to be taken in a limiting sense.
The present invention makes use of standard relational database technology such as that found in the commercial product Oracle Relational Database Management System (“Oracle”) that is marketed by Oracle Corporation, World Headquarters, 500 Oracle Pkwy., Redwood Shores, Calif. 94065. All references to the retrieval and storage of information will be done in a standard relational database, and will use standard procedures for doing so, including structured query language (“SQL”) commands. When the term “query” is used as a noun, “query” means comparison criteria that are used to extract all the records matching the comparison criteria. When the term “query” is used as a verb, “query” means to extract records from a database that match specified comparison criteria. The operations and functions of relational databases discussed in this patent application are well known to those of ordinary skill in the database management field. Those operations and functions can be found in numerous texts, including Oracle users' and developers' manuals.
I. Hardware
Referring now to FIG. 1, one embodiment of the relational database management system for identifying the raw materials consumed in the manufacture of a chemical product is shown (the “system”). The user of the system will access the system through a client machine (e.g., a personal computer) ( 1 ) that is connected to a computer network ( 3 ), such as the Internet, via a modem ( 2 ) or other communications device. Presently, one embodiment of the client machine is a personal computer with a processor speed of at least 800 MHz, system memory of at least 64 MB, a monitor and keyboard, and running Internet Explorer, version 4.0 or later, or Netscape, version 4.0 or later. And of course, the present invention can be practiced on a computer that is slower, or has less memory, or a computer that is faster, or has greater capability, than the embodiment of the personal computer described above. A user can send inputs to the system from a personal computer via a computer network ( 3 ). The system comprises a server ( 4 ), with its own computer processor and associated memory, and running relational database software. One embodiment of the computer network is a global TCP/IP based network such as the Internet or an intranet, although almost any well known LAN, MAN, WAN, or VPN technology can be used.
II. Relational Database Interface
In one embodiment, the user will interface with the system via a web site over the Internet, although, of course, other interface methods are available as noted above.
III. Database Structure
In one embodiment, the database structure comprises two tables: (i) a table of companies and (ii) a table of synonyms of chemical products and raw materials. The table of companies comprises the following fields:
(1) Name of Company;
(2) Chemical Products; and
(3) Raw Materials.
Such databases can be obtained from commercial vendors such as the Chemical Buyers' Guide, published by Sevak Publications Pvt. Ltd. The database can also be a functionally uniform database such as a database of the dye industry or pharmaceuticals in development. The Name of Company field contains the name of a company. The Chemical Products field includes all chemical products manufactured by a company within a certain timeframe. And the Raw Materials field includes all the raw materials purchased by a company within a certain timeframe. When multiple entries are made in a record for a certain field, the entries are separated by a delimiter.
The table of synonyms of chemical products and raw materials comprises a field for the name of a chemical product or raw material and a field for synonyms of the chemical product/raw material.
IV. Identifying the Chemical Products, the Manufacturing Processes of Which, Consume a Particular Raw Material
Referring to FIG. 2, the process or flow chart for identifying the chemical products, the manufacturing processes of which, consume a particular raw material is illustrated. As shown in FIG. 2, the initial step is to enter a name of a raw material. In one embodiment, inputs will be entered remotely by a user on a personal computer connected to the Internet. The user then sends the input to the system, which includes the relational database described above. As shown in block 2 , the system generates a list of synonyms of the raw material from a table of synonyms. This list may be stored in memory on a temporary basis. As shown in block 3 , the system then creates a query consisting of the raw material and its synonyms.
As shown in block 4 , the system compares the query to a subset of the records in the database to generate a list of records containing the raw material or at least one of the synonyms of the raw material, or both. This subset of records is selected randomly from the database containing anywhere from 1% to 10% of the companies in the database. The query is compared to the subset of records in the database using standard relational database technology. The system generates a list of records that contains the raw material or at least one synonym of the raw material, or both. This list may be stored in memory on a temporary basis. For example, if the raw material “2-octyl-1-dodecanol” is used as a query, the system would identify each record in which “2-octyl-1-dodecanol,” or one of its synonyms, occurs in the Raw Materials field.
As shown in block 5 , once the system generates a list of records, the system generates a list of pairs. This list of pairs may be stored in memory on a temporary basis. A pair is defined as the raw material of the query and one of the chemical products contained in one record from the list of matching records. Using the example from the previous paragraph, if the raw material “2-octyl-1-dodecanol” is entered as a query, and Company A has purchased “2-octyl-1-dodecanol,” then the system will generate pairs for each of the chemical products manufactured by Company A. So if Company A produces hydrocortisone, estriol, and bifonazole, the system will generate three pairs matching “2-octyl-1-dodecanol” with the aforementioned chemical products respectively.
As shown in block 6 , after the system identifies all pairs, it creates a ratio for each pair. The numerator of the ratio is the number of times that a pair occurs in the subset of records. The denominator of the ratio is the number of records that the raw material of the query, or at least one of its synonyms, appears in the subset of records. For example, in a subset of 100 records, if a given pair occurs 10 times, the numerator of the ratio is 10. If the raw material of the query, or at least one of its synonyms, appears in the subset of 100 records 15 times, the denominator of the ratio is 15. Thus, the overall ratio would be 10 divided by 15 or 0.667.
As shown in block 7 , the system calibrates a constant based on historical comparisons of pairs within a database. The constant is set at a level that is determined to be accurate by chemical analysis for pairs within a particular database. For example, if the constant is set at 0.7, the ratio for a pair (a particular raw material and a particular chemical product) would have to be 0.7 or higher in order for the pair to be considered “legitimate” by the system. Once a constant has been calibrated, the constant may be fixed for that database so that subsequent queries to the system would skip steps 4 through 7 .
As shown in block 8 , after the system sets a constant for the database, the query is compared against all records in the database to generate a list of records containing the raw material or at least one of the synonyms of the raw material, or both. As shown in block 9 , after the system generates a list of records, the system generates a list of pairs in a manner similar to that described above. As shown in block 10 , the system creates a ratio for each pair in a manner similar to that described above. As shown in block 11 , the system then compares each pair's ratio to the constant. When a pair's ratio meets or exceeds the constant, the system adds the pair to a list of hits. This list of hits may be stored in memory. Hits are pairs that are considered accurate enough to be reported to a user.
As shown in block 12 , the system uses the list of hits to create a table comprising the chemical products, the manufacturing processes of which consume a particular raw material. As shown in block 13 , the results of the system are reported to the user. Results are chemical products that are included in the table of hits. In one embodiment of the invention, results are displayed on the user's computer monitor.
In table 1 below are the results of the system when the raw materials “1,2,4-trichlorobenzene,” “10-camphorsulfonic acid sodium salt,” and “2-octyl-1-dodecanol,” respectively, are used as an input on a database that is derived from the Chemical Buyer's Guide database published by Sevak Publications Pvt. Ltd.
TABLE 1
Results of Queries Using Selected Raw Materials
Raw Material
Chemical Products
1,2,4-
Tetradifon;
trichlorobenzene
Tetrachlorvinphos;
Dicamba
10-camphorsulfonic
Guaiacol;
acid sodium salt
Dipyrone
2-octyl-1-
Hydrocortisone;
dodecanol
Bifonazole;
Simenthicone;
Estriol
While this description has focused on the entry of a raw material as a query, a chemical product can be entered as the initial input to the system. The system would then follow the steps listed above, except that the chemical product would be paired with raw materials contained in records in the database, and the user will be presented with a list of raw materials consumed in the manufacture of the chemical product. For example, in table 2 below are the results of the system when the chemical products “acrylic emulsions,” “alachlor,” and “ioxynil,” respectively, are used as an input on a database that is derived from the Chemical Buyer's Guide database published by Sevak Publications Pvt. Ltd.
TABLE 2
Results of Queries Using Selected Chemical
Products
Chemical Products
Raw Materials
Acrylic emulsions
n-butyl acrylate;
vinyl acetate;
styrene;
formaldehyde;
polyvinyl alcohol
Alachlor
Formaldehyde;
chloro acetate
chloride; 2,6
diethyl aniline;
4-hydroxy
benzaldehyde;
hydroxyl amine
Ioxynil
Hydrocortisone;
bifonazole;
simenthicone;
estriol
Having now described an embodiment of the invention, it should be apparent to those skilled in the art that the foregoing is illustrative only and not limiting, having been presented by way of example only. All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same purpose, and equivalents or similar purpose, unless expressly stated otherwise. Therefore, numerous other embodiments of the modifications thereof are contemplated as falling within the scope of the present invention as defined by the appended claims and equivalents thereto.
Moreover, the techniques may be implemented in hardware or software, or a combination of the two. Preferably, the techniques are implemented in control programs executing on programmable devices that each include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device and one or more output devices. Program code is applied to data entered using the input device to perform the functions described and to generate output information. The output information is applied to one or more output devices.
Each program is preferably implemented in a high level procedural or object oriented programming language to communicate with a computer system, however, the programs can be implemented in assembly or machine language, if desired.
Each such computer program is preferably stored on a storage medium or device (e.g., CD-ROM, hard disk or magnetic diskette) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the procedures described in this document. The system may also be considered to be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner. | A system and method are disclosed that allow a user to identify, within a certain level of confidence, the raw materials consumed in the manufacture of a particular chemical product. In addition, the system and method allow a user to identify, within a certain level of confidence, the chemical products, the manufacturing processes of which, consume a raw material. The system compares a raw material or chemical product to a database of companies comprising the raw material purchases of companies, as well as the chemical products manufactured by companies. Through a statistical analysis, the system reports results to the user that meet a pre-established threshold of accuracy. | 8 |
PRIORITY CLAIM TO RELATED APPLICATIONS
This application is a U.S. national stage application filed under 35 U.S.C. §371 from International Application Serial No. PCT/GB2013/050236, which was filed Feb. 1, 2013, and published as WO 2013/114131 on Aug. 8, 2013, and which claims priority to United Kingdom Application No. GB 1201763.8, filed Feb. 1, 2012, which applications and publication are incorporated by reference as if reproduced herein and made a part hereof in their entirety, and the benefit of priority of each of which is claimed herein.
This invention relates to a radiating device and to a media exposure device.
In the field of visible/Infra Red (IR)/Ultra Violet (UV) Light Emitting Diode (LED) printing, patterning or marking, it is desirable to have as much control as possible over the position, power, wavelength and other properties of the emitted light so as to produce the highest possible quality printed product. One key part of the process is ensuring that the LEDs themselves are accurately positioned and all emitting the same (or a controlled) spectrum and power of light.
Many LED printers use micro LEDs as the source of light. This is because they have many advantageous properties such as small spot sizes that correspond to high resolution printing. Macro LEDs are also used which have the advantage of having a high power output. In either case, the accurate placement of these LEDs is required. In the case of macro LEDs, they are usually placed onto a Printed Circuit Board (PCB) robotically. Accuracies of around 10 microns are commercially common, but they often slip out of place during mounting or in use. There is therefore a need to ensure that the light emitted illuminates only the correct portion of the print medium. Similar LEDs also vary in the wavelength and power they emit, sometimes by up to 20 nm and 20% respectively. When illuminating a photosensitive medium, the wavelength of the light has a significant influence on how the medium reacts. Pre-selecting LEDs which have exactly the same light spectrum is inefficient and costly. There is therefore a need to control the wavelength of the emitted light after mounting the LEDs onto the PCB.
The present invention aims to solve at least some of these problems.
STATEMENTS OF INVENTION
According to one aspect of the invention, there is provided a radiating device, including: a holding structure; a substrate having a plurality of diodes mounted thereon; and a radiation modification element for modifying the radiation emitted by the diodes; the substrate and the radiation modification element being secured by the holding structure in an arrangement wherein the diodes can emit radiation from the device and wherein the radiation modification element is spaced from the diodes in the radiation path of the diodes.
According to another aspect of the invention, there is provided a media exposure device for exposing media, including: a radiating device as herein described; and a telecentric lens and/or tapered optic fibre bundle secured to the holding structure of the radiating device in an arrangement wherein the telecentric lens and/or optic fibre bundle is substantially in register with the radiation path of the diodes.
Preferably, the radiation modification element includes means for filtering the radiation.
Preferably, the filtering means includes at least one radiation filter layer.
Preferably, the radiation modification element includes a plate which allows the passage therethrough of the radiation, and wherein each radiation filter layer is deposited on said plate.
Preferably, the radiation modification element further comprises means for masking the radiation.
Preferably, the masking means defines a number of apertures, each aperture substantially being in register with the radiation path of a particular one of the diodes.
Preferably, the radiation modification element includes a plate which allows the passage therethrough of the radiation, and wherein the masking means is in the form of an opaque layer deposited on said plate which is opaque to the radiation.
Preferably, each radiation filter layer is deposited on the opaque layer, and more preferably each radiation filter layer covers at least a portion of the apertures
Preferably, the diodes are light emitting diodes emitting electromagnetic radiation substantially within the visible spectrum.
Preferably, the diodes are infrared diodes emitting electromagnetic radiation substantially within the infrared spectrum.
Preferably, the diodes are ultraviolet diodes emitting electromagnetic radiation substantially within the ultraviolet spectrum.
Preferably, the radiation modification element is in the form of a glass plate.
Preferably, the radiation modification element is an optic fibre plate in which the fibres are oriented with their axes substantially parallel to the radiation path of the diodes.
Preferably, the holding structure includes a spacing element disposed between the substrate and the radiation modification element.
Preferably, the spacing element defines at least one opening and is disposed in an arrangement wherein each diode is in register with an opening of the spacing element.
Preferably, the spacing element defines a number of slots, each slot being in register with a different subset of the diodes.
Preferably, the spacing element is in the form of a ceramic plate.
Preferably, the holding structure includes at least one heat dissipation element of a material of high thermal conductivity which is secured in contact with at least a portion of the substrate.
Preferably, the radiating device further comprises a front heat dissipation element secured within the holding structure in an arrangement wherein it is in contact with at least a portion of the face of the substrate on which the diodes are mounted.
Preferably, the radiating device further comprises a back heat dissipation element secured within the holding structure in an arrangement wherein it is in contact with at least a portion of the face of the substrate opposite to the face on which the diodes are mounted.
Preferably, the holding structure includes a base plate and a front plate adapted to be coupled to one another thereby to secure the other components of the device between said base and front plates.
Preferably, the base plate is adapted to act as a heat sink
Preferably, the base plate is of aluminium.
Preferably, the front plate includes an aperture in the radiation path of the diodes.
Preferably, the radiating device further comprises temperature sensing elements situated on the diode substrate, preferably in the form of thermistors.
Preferably, the radiating device further comprises means for actively controlling the temperature of the device.
Preferably, the means for actively controlling the temperature of the device comprises a Peltier device.
Preferably, the means for actively controlling the temperature of the device comprises an air blower.
Preferably, the temperature sensing elements and the temperature controlling means form a feedback control loop for actively cooling the device.
Preferably, the diodes are spaced substantially at a predetermined distance from the telecentric lens and the telecentric lens is image-space telecentric, thereby focusing radiation emitted by the diodes at a distance which is within a particular range of distances from the device.
Preferably, each of the diodes is spaced substantially within a predetermined range of distances from the telecentric lens and the telecentric lens is bi-telecentric, thereby focusing radiation emitted by the diodes at a distance which is within a particular range of distances from the device.
Preferably, the object aperture of the telecentric lens is of a size corresponding to the cross-sectional area of the radiation path of the diodes at the object aperture.
Preferably, the image aperture of the telecentric lens is of a size corresponding to the desired resolution to be achieved on the media.
Preferably, the telecentric lens has a magnification factor of between 2:1 and 10:1, and preferably between 4:1 and 6:1, more preferably 5:1, and yet more preferably 4.72:1.
Preferably, the telecentric lens comprises means for adjusting its image lens.
Preferably, the adjustment means comprises a bevel adjuster for adjusting the position of the image lens.
Preferably, the telecentric lens is made of fused quartz.
Preferably, the telecentric lens is made of fused silica.
The terms medium/media, as used herein, refer to any media that may be optically exposed so that an image, pattern or mark can then be generated on the media. An illustrative example of such media is photographic paper. It should also be remembered that where the term ‘printing’ or other related terms are used, we do not intend to refer to the deposition of inks and such like onto media. In general terms, ‘printing’ in the context of the present application is the exposure of print media with light and/or radiation, and the treatment of that media to yield an image, pattern or mark.
According to one broad aspect of the invention, there is provided an LED array optically coupled to a telecentric lens system.
According to another aspect of the invention, there is provided an LED array mounting structure including an LED array and a lens system, wherein the lens system is optically coupled to the LED array and is adapted to image the LED array onto a print medium at a reduced size, the lens system being a telecentric lens system.
Preferably, the telecentric lens has image-space telecentricity.
More preferably, the telecentric lens is bi-telecentric.
The present invention also extends to a method of printing using a telecentric lens and radiating device combined to form a media exposure device.
According to another aspect of the invention, there is provided a media exposure device for exposing media, including a radiating device as described herein and above; and a telecentric lens secured to the holding structure of the radiating device in an arrangement wherein the telecentric lens is substantially in register with the radiation path of the diodes.
According to another aspect of the invention, there is provided a media exposure device for exposing media, including a radiating device as described herein and above; and a tapered bundle of optic fibres of a predetermined length and having substantially the same orientation, each fibre having substantially the same tapered profile, the tapered bundle thereby defining a planar wide end and a planar narrow end; the tapered bundle being secured to the holding structure of the radiating device in an arrangement wherein its wide end is substantially in register with the radiation path of the diodes. The tapered bundle of optic fibres being described in more detail in WO0135633 published 17 May 2001 with the title ‘Digital Photographic Reproduction Apparatus’ which is hereby incorporated in its entirety by reference.
Telecentric lenses can be manufactured in a very consistent manner with little discrepancy in their magnification properties. The use of telecentric lenses in this context thus affords the advantage of being able to produce print heads with lenses of substantially identical magnification, resulting in more accurate printing.
Telecentric lens may be transparent to UV light. This affords the advantage of being able to print using UV LEDs or other UV radiating elements.
In addition, telecentric lenses have a much larger depth of field than other optical systems, meaning that the spot size does not deviate greatly if the print medium varies in distance from the lens. This affords the advantage of reduced printing errors which would have been caused by the print medium varying in distance from the lens.
The invention extends to any novel aspects or features described and/or illustrated herein.
Further features of the invention are characterised by the other independent and dependent claims.
The invention extends to methods and/or apparatus substantially as herein described with reference to the accompanying drawings.
Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.
Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features disclosed in the description, and (where appropriate) the claims and drawings in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.
It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.
Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described, purely by way of example, with reference to the accompanying drawings, in which:
FIG. 1( a ) shows an exploded view of a radiating device according to one aspect of the invention;
FIG. 1( b ) shows a cross-sectional side view of the radiating device of FIG. 1( a ) when assembled;
FIGS. 2( a ) and ( b ) show a radiation modification element of the radiating device of FIG. 1 ;
FIG. 2( c ) shows an enlarged view of one example of the construction of the radiation modification element of FIG. 2 ;
FIG. 2( d ) shows a graph depicting example spectral properties of the LEDs, print media and radiation modification element;
FIGS. 3( a )-( d ) show an example LED substrate of the radiating device of FIG. 1 ;
FIGS. 4( a ) and ( b ) shows an example spacing plate of the radiating device of FIG. 1 ;
FIGS. 5( a ) and ( b ) show an example front thermal pad of radiating device of FIG. 1 ;
FIGS. 6( a ) and ( b ) show an example rear thermal pad of the radiating device of FIG. 1 ;
FIGS. 7( a ) and ( b ) show an example top plate of the radiating device of FIG. 1 ;
FIGS. 8( a )-( c ) show an example back plate of the radiating device of FIG. 1 ;
FIG. 9 shows a ray diagram of a telecentric lens system;
FIG. 10 shows an example telecentric lens adapted for use with the radiating device of FIG. 1 ;
FIG. 11 shows a schematic diagram of the telecentric lens of FIG. 10 connected to the radiating device of FIG. 1 and a cage mount;
FIG. 12 shows two telecentric lenses of FIG. 11 connected together;
FIG. 13 shows the telecentric lenses of FIG. 12 in an alignment stage; and
FIG. 14 shows a flow diagram of an alignment process.
DETAILED DESCRIPTION
The radiating device 100 shown in FIG. 1( a ) contains numerous elements constructed around an LED substrate 102 . The LEDs 104 are mounted to the substrate, preferably in strips. In the example shown, three strips are illustrated, corresponding to an embodiment where full colour printing is achieved via Red, Blue and Green (RBG) LEDs 104 exciting different active elements of a print medium. The substrate 102 is described in more detail below with reference to FIG. 3 .
The radiating device 100 is adapted to form part of a larger print head unit which, in combination with appropriate additional mechanical and electrical components, together with a lens system in certain examples, selectively exposes a print medium (such as photographic paper) in order to produce a patterned article. In this document, the term LED is used to refer to a Light Emitting Diode adapted to radiate light of any wavelength unless otherwise stated, that is, including ultraviolet, visible and infrared ‘light’.
The substrate 102 is mounted onto a thermal pad 106 which is situated further away from the print medium when in use (as indicated by FIG. 1( a ) ). This aids the dispersal of heat produced by the LEDs 104 themselves. Without temperature controlling precautions, the LEDs 104 would heat up in use which would cause a number of unwanted side effects. In particular, the optical properties of the LEDs and of other elements in the system are temperature dependant, which affects performance. In extreme circumstances excessive heat can cause severe damage to the LEDs 104 . The thermal pad 106 is in thermal contact with the substrate at least adjacent to the area of the substrate to which the LEDs 104 are mounted, as this is where the majority of the heat is produced. Active temperature control may also be provided as is described in more detail below.
Below the substrate 102 (towards the print media) is another thermal pad 110 . This is similar to the thermal pad 106 , but is shaped so that it does not obscure the light emitted from the LEDs 104 . The substrate is thus ‘sandwiched’ between the two thermal pads 106 , 110 . These heat pads are described in more detail below with reference to FIGS. 5 and 6 .
Above the first heat pad 106 (further away from the print media) is a back plate 108 . In the example shown in FIG. 1 , this conforms to the shape of the heat pad 106 . This is made out of a material with a low thermal resistance (high thermal conductance) such as aluminium. This acts to guide the heat produced by the LEDs 104 away from the LEDs 104 , and to dissipate it into the surrounding environment, or into a further heat sink (not shown).
Below the lower thermal pad 110 (towards the print media) is a spacing element 112 (preferably in the form of a ceramic plate). This plate 112 is provided with three parallel apertures, and the plate 112 is positioned so that these apertures are located in register with each of the three LED strips. This is discussed in more detail below with reference to FIG. 4 .
Adjacent to the spacing element 112 , further towards the print media, is the radiation modification element 114 . This element 114 modifies the properties of the light passing through the system, which is discussed in more detail below with reference to FIG. 2 .
The component shown to be nearest the print media in FIG. 1 is front plate 116 . This adds to the structural rigidity of the device as a whole, and, together with back plate 108 , enables all the components to be securely fastened together by screws 118 . The front plate 116 and back plate 108 are shown in more detail in FIGS. 7 and 8 respectively.
FIG. 1( b ) shows a side view of the assembled radiating device. Screws 118 pass through apertures 700 (shown in FIG. 7 ) provided in the top plate 116 and screw into screw-threaded cavities 800 provided in the back plate 108 . By tightening these screws 118 , the components are secured in place.
FIG. 2 shows the radiation modification plate (or correction plate) 114 in more detail. In order to correct for inaccurately placed LEDs 104 , the radiation modification plate 114 is provided with a mask. This mask is an optically opaque material (for the relevant wavelength(s) of light being used) that is applied onto the plate 114 using Physical Vapour Deposition (PVD). This process applies a very thin layer of the opaque material (several atoms thick) in a very precise pre-defined pattern. Alternatively this could be achieved by Chemical Vapour Deposition (CVD), hand coating and/or use of gelatine filters. In any such example, the pattern is to cover the plate 114 whilst leaving uncovered the desired locations of the LEDs 104 . Any misplaced LEDs will have the light they emit blocked from transmitting further towards the print medium. The power that reaches the print medium from these misplaced LEDs would be less than accurately placed LEDs, but by a negligible amount if the misplacement is small. The defects in printing due to errors of this kind are far less serious than the defects created by misalignment and cross-talk between neighbouring LEDs. In one example, the mask is placed on the side nearest the LEDs (furthest away from the print medium). This reduces the possibility of diffraction and cross talk by minimising the amount of light entering the radiation modification plate 114 . In a further example, the mask might be placed on the other side of the plate 114 .
Further to this opaque coating, subsequent coatings are applied in a similar manner, either applied on the same side as the mask or on the opposing side. These coatings alter the properties of the light which could affect the quality of the final printed product, namely the emission spectrum of the LEDs. These filters may again be applied onto the plate using PVD, CVD, hand coating and/or use of gelatine filters. In the example shown, there are three strips of LEDs; red, blue and green. It is important that each LED is of the same colour as the others in the strip. This is because the print media has a wavelength dependent sensitivity. Even if LEDs are produced in identical conditions, their peak wavelength may vary by up to 20 nm, which is enough to produce noticeable errors in the final printed product. Furthermore, the LEDs may produce light with a spectrum which extends into other active areas of the print media. For example, in the RBG example given, the wavelength response of some media is such that part of the ‘green’ sensitive area can be activated by the tail of the spectrum from a blue LED. There is therefore a need to constrain the wavelength of the LEDs within a tight window. Band pass filters which block light of unwanted wavelengths are employed for this purpose. The filters are deposited onto the specified areas of the radiation modification plate 114 , for example, a filter for blue light is applied over the areas through which the blue light is radiated. Alternatively, a single filter with ‘windows’ at each of the relevant wavelength bands could be applied, covering each of the three different colour LED strips. This would mean fewer PVD iterations, and potentially less additional material through which the light needs to pass.
In the RBG example, there may not be a need for a ‘red’ filter as there is negligible overlap between the red sensitive spectrum of the media with that of other colours. In this case, only green and blue filters would be necessary. The filters shown in FIG. 2( d ) are illustrated schematically and in reality are ‘bandpass’ filters, which cut off wavelengths above or below a certain wavelength. They will also not have perfectly sharp edges, rather have a steep drop off and a small ‘tail’. This is described in more detail below with reference to FIG. 2( d ) .
The radiation modification plate 114 , in one example, is a sheet of glass, approximately 0.5 mm-1 mm thick, preferably around 0.69 mm thick. In one example, the glass used is optical grade glass so that there is less scattering or attenuation and that a broader spectrum of light can be transmitted through it. However it is also possible to use standard glass.
In a preferred example, the radiation modification plate 114 is a sheet of ‘glass fibres’, or an ‘optic fibre plate’ as shown by FIG. 2( c ) . This is a collection of optical fibres collected or bundled and fused together. This would also be approximately 0.5 mm-1 mm thick, preferably around 0.69 mm. FIG. 2( c ) shows a magnified view of such a construction. The plate 114 is comprised of a large number of individual optical fibres 200 which have been bundled and fused together. In one example each optical fibre 200 is around 18-20 μm in diameter. Typically the plate is formed by “salami-slicing” or shaving off a section of a length of fused optical fibres thereby forming the plate 200 . Each optical fibre 200 consists of cladding 202 and a core 204 .
This construction provides a number of advantages over a sheet of glass. In particular, there is less scope for cross-talk between neighbouring LEDs, and scattering in the radiation modification plate 114 is reduced. The fibres 200 have a low Numerical Aperture (NA), meaning that there is less ‘cross talk’ between neighbouring LEDs. The light is also guided down much more accurately through the plate 200 . The fibres 200 guide the light directly down, whereas a glass plate would allow some spreading, which would eventually lead to errors on the final printed item. The use of a fibre plate is also preferable when using a ‘fibre taper’ as discussed below as the fibre-to-fibre interface results in less scattering and other losses than a glass-to-fibre interface.
FIG. 2( d ) shows the spectrum of LEDs, medium response sensitivity and filters, illustrating the function of the filters. In an ideal system, each LED would emit a single wavelength of light which exactly corresponds with a single wavelength to which the media is sensitive. In real systems this is not the case as the LEDs emit light in a range of wavelengths, and the media is sensitive to a range of wavelengths. As shown in FIG. 2( d ) , the radiation from certain LEDs can excite the media in a range of varying colours. This is best seen with the ‘Blue LED spectrum’ overlapping with the ‘media response sensitivity to green light’ curves. The result of such overlap means that LED light that is meant to activate ‘blue’ in the media, also activates ‘green’ (and vice versa). This leads to errors in the final colour of the printed item. To overcome this, filters are employed so that only light that activates the correct colour on the print media is transmitted to the print medium. These band-pass filters are shown schematically by dashed blocks in FIG. 2( c ) , indicating the wavelength range that is allowed to propagate. There is a trade off between letting more light through and avoiding overlap which is dependent on a number of factors such as the speed and quality of printing required.
FIG. 3( a ) shows a more detailed view of the front face (light emitting side) of the LED substrate 102 . There are approximately 100 individual LEDs 104 in each strip, each 0.4 mm wide, which together span a width of approximately 40 mm. In another example, LEDs with a die size of between 0.3 mm and 1 mm are used. The LEDs are mounted to the substrate using surface mounting techniques. Each set of 100 LEDs 104 - 1 , 104 - 2 , 104 - 3 are arranged in two rows of 50 so that the emission profiles of adjacent LEDs 104 in each row overlap to such a degree that components of an image, pattern or mark printed on a photo-sensitive medium and attributable to adjacent LEDs are not readily resolvable. In an alternative example, the LEDs might be arranged in a single row in a non-overlapping fashion. The different rows 104 - 1 , 104 - 2 , 104 - 3 are shown to be linearly offset from one another; this is to avoid ‘banding’ where errors in the movement of the print head results in under or over exposure between print swathes. This linear offset means that the join between adjacent swathes of the final image resulting from exposure of the photographic medium by the red row 104 - 1 (say) occurs at a different location on the photosensitive medium to joins between adjacent swathes of that image which are attributable to the blue and green rows 104 - 2 , 104 - 3 . In an alternative example, the different rows 104 - 1 , 104 - 2 , 104 - 3 are arranged with their ends substantially aligned. Further details relating to the LED array are provided in WO2007138318, published 6 Dec. 2007 with the title ‘Improvements Relating to Optical Printers’ which is incorporated in its entirety herein by reference.
In the example of an RBG array, the wavelengths of the different rows 104 - 1 , 104 - 2 and 104 - 3 would be 690-700 nm (R), 430-440 nm (B) and 540-550 nm (G).
In addition to the passive temperature management elements described above, in certain examples, active cooling control is provided. The wavelength and power of light emitted from the LEDs varies depending on the ambient temperature, and in one example, temperature control of the LEDs within a range of 0.5° C. is necessary. In one example, the active cooling elements are in the form of a Peltier element and/or an air-blower situated outside the radiating device 100 . In one example, in addition to the LEDs 104 , there are also thermistors 302 mounted on the substrate 102 . These are preferably spaced as close to the LED strips 104 - 1 , 2 , 3 as possible, in one example, between the strips. The placement of thermistors 302 enables accurate temperature measurements of the LEDs 104 to be taken. These measurements can be fed to the active cooling elements to effect feedback temperature control of the substrate 102 .
FIG. 3( c ) shows a more detailed view of the rear face of the LED substrate 102 . This shows a number of connectors 300 which enable the individual LEDs to be connected via wire-bonding to further circuitry to control individually the power and timing of each of the LEDs. In one example Application Specific Integrated Circuits (ASICs) or Field Programmable Gate Arrays (FGPAs) are used for this purpose. In certain examples, two connectors 300 for each LED, and two for each thermistor 302 are provided. In one example, a printed circuit board or motherboard is provided which is connectable to the connectors, and the location holes 304 are provided to guide this board into place.
FIG. 4 shows the spacing element 112 described above with reference to FIG. 1 . In the example shown there are three parallel apertures 400 which are locatable in register with the three rows of LEDs 104 - 1 , 104 - 2 , 104 - 3 . This plate acts as a spacer so that the LEDs and wire bonds are protected from being damaged when pressed against the other components in the device. In other systems, LEDs and wire bonds are coated with epoxy in order to protect them. This epoxy can damage the connectors themselves upon application and in use, and also introduces another source of scattering for the light. The introduction of the spacing element 112 thus offers better protection for the LEDs and wire bonds and improves the optical properties of the system. In a preferred example, this plate 112 is less than 1 mm thick, and preferably 0.51 mm thick.
The plate 112 is preferably ceramic, due to its advantageous thermal properties. Ceramic materials have a low thermal conductance, which means that heat produced by the LEDs is not transferred to the radiation modification plate 114 which could adversely affect its optical properties of the plate 114 .
FIGS. 5 and 6 show the thermal pads which were described above in relation to FIG. 1 . The front thermal pad 110 is shaped to correspond with the shape of the substrate 102 . It has an aperture large enough to accommodate the ceramic plate 112 and the radiation modification plate 114 .
The back thermal pad 106 is similarly sized, but has two apertures which correspond in size and position to the connectors 300 provided on the rear face of the substrate 102 .
Each pad has a high thermal conductivity so as to draw heat from the substrate 102 (where the LEDs 104 are producing heat) and conduct it to the front 116 and back 108 plates respectively, which dissipate the heat into the surroundings. The pads 110 , 106 are in thermal contact with both the substrate 102 and the front 116 or back 108 plate. In a preferred example, they are less than 1 mm thick, and preferably 0.67 mm thick.
FIGS. 7 and 8 show the top plate 116 and back plate 108 of the radiating device. The faces of these plates have a size larger than the that of the other components, but correspond with one another. This is so that screws 118 can pass through holes 700 and fasten into corresponding screw-threaded cavities 800 in the back plate 108 without interfering with intermediate components. The act of tightening these screws 118 secures the components together, thereby ‘sandwiching’ them in place. To avoid damaging the components, a gasket may be introduced between the front and back plates, and/or between any other pair of layers within the ‘sandwich’.
The front plate has an aperture 702 of a size corresponding to that of the radiation modification plate 114 and ceramic plate 112 . The aperture 702 is preferably shaped so that the top (print medium facing) edge protrudes slightly so as to hold the plates 114 , 112 in place when secured. This is shown in FIG. 1( b ) . Alternatively or in addition the plates may be secured together in some other manner, for example, they may be glued together.
The back plate 108 has two apertures 802 which are shaped so as to allow access to the electrical connectors 300 of the substrate plate 102 . FIGS. 8( b ) and ( c ) show that the back plate 108 has a depth far greater than any other component, preferably 10 mm thick. This is to aid in its role as a heat sink. The plate 108 is made from a material with a high thermal conductance, preferably aluminium. The extra depth provides greater heat capacity and thus serves as a more efficient heat sink.
Alternatives and Modifications
The above description mainly focuses on one example of a radiating device. There are of course numerous alternatives and modifications that can be made and still remain within the scope of the invention.
For example, although the above description and corresponding figures describe an RBG macro-LED array as being the light source, other arrangements are possible, and preferable in certain circumstances. An alternative arrangement would be to have an LED array of Infra Red (IR) and/or Ultra Violet (UV) LEDs. This arrangement would enable the device to print onto optically sensitive media.
The examples shown above all describe a distinct print head radiating device, but it is envisaged that a plurality of such radiating devices will be coupled together to form part of a much larger print head, that is, a bar-like structure.
In an LED printhead, the light produced at the bottom of the radiating device as described above is often not of a small enough spot size to generate high resolution images on the print media. In order to rectify this, the radiating device is attached to an apparatus which reduces the spot size. This could be in the form of a ‘tapered fibre’, details of which are described in WO0135633 published 17 May 2001 with the title ‘Digital Photographic Reproduction Apparatus’ which is hereby incorporated in its entirety by reference. Alternatively, this reduction could be performed by a lens system as described below.
In order to get the required resolution for the final printed article, the accurate control of exposure to the medium is required. The size of an area which is exposed by a single LED is called the ‘spot size’ and is often the limiting factor of the resolution of the printed article. For this reason, reduction of the spot size is an essential function of a high resolution LED printer. As discussed above, one solution is to use a ‘fibre taper’. This is a bundle of optical fibres which are heated and pulled to form an hourglass shaped bundle which is then cut in half. This generates a device which focuses light entering the bundle down onto a smaller spot size. An alternative solution is to use a telecentric lens system as described below.
In the description that follows, the object aperture of the lens system is the aperture which is to be illuminated by the LEDs and the image aperture is the aperture of the lens system which projects the image onto the print medium.
FIG. 9 shows a schematic ray diagram of a bi-telecentric lens system. Telecentric lenses are different from standard lens systems as they correct for perspective. For this reason they are used in the imaging of objects such as apertures or objects which are vibrating. The correction for perspective in these situations allows a user to accurately measure the size of an aperture or vibrating object, which would be difficult when using a standard lens due to magnification changes or distortion due to lack of focus. The property which allows these effects is that for a range of distances there is effectively a constant magnification.
This means that the spot size produced by an LED illuminating a telecentric lens will be substantially constant for a range of distances away from the image aperture. This range of distances is called the ‘depth of field’ of the system. Conventional lens systems have a very limited depth of field, which results in large errors when a part of the print medium is at a different distance from the previous part. For example, the depth of field of the ‘fibre taper’ described above is in the micron range whereas for a typical telecentric lens system it is in the millimetre range. The image lens 950 can be adjusted in the system, moved longitudinally along the axis of the lens so as to ‘fine tune’ the magnification factor. This may be necessary as two telecentric lenses produced to the same specification may have slightly different magnification factors. In order to correct for this, a grid is imaged through a lens, and matched up to a calibration grid by altering the position of the image lens 950 via bevel adjuster 906 ( FIG. 10 ). In one example, the lens 950 can be adjusted by up to 0.5 mm using the bevel adjuster 906 .
The depth of field of a telecentric lens is determined by two factors—the tolerable error in magnification and the ‘telecentric slope’ of the lens by the following formula:
DOF = Δ M · 180 t · π
Where DOF=Depth of field range
ΔM=Change in spot size radius (in the same units as DOF) t=Telecentric slope of lens (‘telecentricity’—in degrees)
For example, if the medium can be placed with an accuracy of 1 mm (required DOF) of the lens and the telecentricity of the lens is 0.15°, the change in spot size radius is 2.6 μm over that 1 mm range. For the system as described herein, where the final spot size diameter is 80 μm, this is error of around 3%. This error increases linearly with increasing telecentricity, so a lower limit on the quality of the telecentric lens can inferred from the maximum error tolerable.
A more general formula for determining the error in spot size as a percentage of the final spot size is given by:
% = DOF · t · π I · mf · 180 × 100
Where l=Initial spot size (size of each LED)
mf=Magnification factor (e.g. a 5:1 lens gives mf=0.2)
For example, if the error tolerable in a system as shown in FIG. 10 and table 1 below is 5%, and the required DOF is 1 mm, the highest telecentricity the lens could have would be 0.23°. In a preferred embodiment, the lens has a telecentricity of below 0.2°, even more preferably below 0.15°.
In one example, where UV LEDs 104 are used the lens is preferably constructed from UV transparent materials such as fused quartz or fused silica. A corollary of using such materials, and to a lesser extent, standard glass, is that the transmission properties are significantly improved. In one example, the intensity of light is increased by 95% compared to a fibre taper.
FIG. 10 shows an example telecentric lens 900 adapted for use with the RBG LED radiating device 100 described above. The print medium 904 and an illumination source 902 have been included in order to show relative distances. Table 1 below describes preferred properties and characteristics of this example:
TABLE 1
Properties of an example telecentric lens adapted for use with RBG LEDs
Item
Design
Type of lens
Bi-telecentric
Effective Focal length
540.24
mm
Magnification
0.21167x (4.72:1)
Effective F#
2.8
Object space NA (LED side)
0.037
Object size (A)
38
mm (diameter)
Image size (B)
8.07
mm (diameter)
Working distance (LED side) (C)
5-6
mm
Working distance (image side) (D)
11.54
mm
Depth of field (LED side)
0.224
mm
Depth of field (medium side)
1.06
mm
Spectral range
400-750
nm
In one example, shown schematically in FIG. 11 , the telecentric lens 900 described above is used in combination with the LED radiating device 100 , also described above, to produce a media exposure device. The telecentric lens 900 is optically coupled to the radiating device 100 by mechanically connecting the radiating device 100 to the lens 900 using a mechanical coupling 912 , in the form of a cage mount 912 . A base portion 911 of the cage mount 912 is attached to a flange 910 which is itself attached to the top of the telecentric lens 900 . This cage mount 912 houses the radiating device 100 and a plurality of controlling motherboards 908 . The radiating device 100 fits into a recess provided in the base portion 911 of the cage mount 912 . The radiating device 100 is shown expanded for clarity. The motherboards 908 contain the necessary electronics to power, control and cool the LEDs 104 . The motherboards 908 are connected to the connectors 300 on the substrate 102 via a further printed circuit board having push connectors, extended pins, or other suitable connecting means, which pass through the apertures in the back plate 108 and rear thermal pad 106 . In one example, the lens 900 is mounted 5 mm below (closer to the print medium 904 ) the LED substrate 102 for optimum operation.
FIG. 12 shows a diagram of two such lenses 900 and cage mounts 912 as described above. An advantage of having multiple devices on the same printhead is that each swathe of print is wider, resulting in faster printing. For this to be possible, accurate alignment of the swathes is necessary, which is discussed in below with reference to FIGS. 13 and 14 .
FIG. 13 shows a diagram of two lenses 900 which during an alignment process. The first lens 900 is attached to a mounting bar 913 using a ‘key-slot mount’ 914 - 1 . This aligns the lens vertically (i.e. at the correct distance from print medium) and ensures it is orthogonal to the print medium. The mounting bar 913 in one example is a print bar along which the print head moves when producing a swathe of print. The second lens is attached to the same print bar 913 by a second key-slot mount 914 - 2 . This is set back longitudinally along the bar 913 by a preset amount, and also laterally offset perpendicular to the bar 913 by a preset amount. This lateral distance sets the distance between the swathes, and must be very accurate otherwise ‘banding’ will occur as discussed above. The longitudinal distance it is set back along the bar 913 does not affect this so does not necessarily need to be finely controlled. The process of aligning the second swathe from the second lens 900 - 2 with respect to the first is described in detail below.
A micrometer 916 is attached to the underside of the cage mount 912 and contacts the lens 900 - 2 . The bolts securing the lens 900 - 2 to the cage mount 912 are loosened or removed. This allows the cage mount 916 (and hence the position of the LEDs 104 ) to be moved relative to the lens 900 - 2 . In one example, the bolt holes are slots so that the bolts can be loosened, then the adjustment to position can be made, then re-tightened. This movement is focused by the lens 900 - 2 , so a 0.1 mm movement of the micrometer results in a 20 μm movement of the swathe at the print medium (for a lens with a magnification factor of 5:1). This allows for the accurate positioning of the second swathe. The second lens 900 - 2 is positioned as accurately as possible to begin with using the key-slot mount 914 - 2 , as only a limited amount of movement can be achieved using the micrometer 916 before the LEDs 104 move out of the lens' field of view. Although FIGS. 12 and 13 show two lenses 900 - 1 , 900 - 2 , any number may be arranged onto a print bar using the method described. A physical limit on the number of lenses may occur however when the weight of additional lenses may make it quicker and more accurate to print using multiple passes of smaller swathes rather than in one large swathe.
FIG. 14 shows a flow diagram of the method used to align an additional swathe with the previous swathe. In step S 1 , the first lens 900 - 1 , together with its radiating device 100 (not shown) is mounted onto the print bar 913 using the key-slot mount 914 described above. The second lens 900 - 2 is then mounted in a similar fashion in step S 2 , offset laterally and longitudinally from the first lens 900 - 1 . A micrometer 916 is attached to the lower panel of the cage mount 911 adjacent to the second lens 900 - 2 and contacts the second lens 900 - 2 itself in step S 3 . The bolts securing the lens 900 to the cage 911 are loosened/removed in step S 4 so that adjustment of their relative positions can take place in step S 5 . This step involves moving the cage 911 (and hence LEDs 104 ) relative to the lens 900 - 2 so that the swathes coincide. In the example of the RBG LED strips 104 - 1 , 104 - 2 , 104 - 3 above, this is where the ‘G’ strip coincides with the ‘R’ strip from the neighbouring array. In one example, there may be some overlap as when the apparatus is in use it expands due to the raised temperature. Such calibration can be worked out once and then used for all subsequent alignments. Step S 6 indicates the feedback loop used to effect the alignment of the swathes. The swathes may be compared by exposing a photosensitive media, or by passing the heads over a camera. When the swathes are suitably aligned, the bolts are tightened in step S 7 and the micrometer 916 is removed in step S 8 . If the printhead is complete (step S 9 ), the process terminates, if another lens 900 is to be added, the process returns to step S 2 .
Table 2 shows example properties of a telecentric lens adapted for use with UV LEDs.
TABLE 2
Properties of an example telecentric lens adapted for use with UV LEDs
Item
Design
Type of lens
Bi-telecentric
Effective Focal length
394
mm
Magnification
0.10x (10:1)
Working F#
2.8
Object space NA (LED side)
0.035
Image space NA
0.178
Field of view (LED side) (A)
48
mm (diameter)
Image size (B)
4.0
mm (diameter)
Working distance (LED side) (C)
5.0
mm
Working distance (image side) (D)
10
mm
Distant of Object to Image (O/I)
130
mm
(<150
mm)
Telecentricity
0.15°
Optical distortion
<0.1%
Relative illumination
>98%
Transmission
>70%
Spectral range
>365
nm (UV LED)
Although the above lenses are described as bi-telecentric, it is envisaged that a lens with just image-space telecentricity may be used. This would suffice as the positioning of the LEDs relative to the object aperture of the lens (distance C) can be controlled to a great degree of accuracy and reproducibility, and does not change once mounted. Conversely, the image side distance D is subject to variation as the print medium is moved for example. It is thus far more important to have image-space telecentricity than object-space telecentricity.
It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.
Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims. | This invention relates to a media exposing device for exposing media. The media exposure device includes a holding structure; a substrate having a plurality of diodes mounted thereon; and a radiation modification element for modifying the radiation emitted by the diodes. The substrate and the radiation modification element are secured by the holding structure in an arrangement wherein the diodes can emit radiation from the device and wherein the radiation modification element is spaced from the diodes in the radiation path of the diodes; and a telecentric lens secured to the holding structure in an arrangement wherein the telecentric lens is substantially in register with the radiation path of the diodes. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to testing flat panel displays (FPDs). More specifically, the present invention relates to testing FPDs using high frequency alternating current (AC) signals.
BACKGROUND OF THE INVENTION
[0002] Flat panel displays (FPDs) are increasingly replacing the conventional cathode ray tube (CRT) as the display type of choice. FPDs are electronic displays in which a flat screen is formed by a two-dimensional array of display elements (or “pixels”). They can be manufactured from a variety of different display technologies. One common display technology utilizes an array of light emitting diodes (LEDs) to form the FPD. An LED is a solid-state electronic device, more specifically a p-n junction or “diode”, which emits photons (i.e. light) when forward biased. The light emitting effect is referred to as injection electroluminescence, a light emitting phenomenon that occurs when minority charge carriers generated by an applied electric field recombine with charge carriers of the opposite type in the diode. The energy of the emitted photon, which determines the wavelength of the emitted light, varies with the band gap of the semiconductor material used (e.g., GaP, GaAs, GaN, etc.) to form the LED.
[0003] Typically, control of the LEDs in an FPD is performed using one of two approaches. According to the first approach, the LEDs are controlled by a row-column grid control pattern and associated row and column drivers/controllers. This approach is known as the “passive matrix” approach. The second approach, known as the “active matrix” approach, uses one or more control transistors at each pixel site to control pixel emission. Because each pixel is controlled by its own associated control transistor(s), active matrix LED FPDs consume less power than passive matrix FPDs, and are able to turn pixels on and off faster than passive matrix displays.
[0004] Another display technology of recent interest is based on the so-called Organic Light Emitting Diode (OLED). Operation of an OLED is similar to that of an inorganic semiconductor LED described above. When two organic materials, one with an excess of mobile electrons the other with a deficiency, are place in close contact, a junction region is formed. When a small forward bias is applied across the diode, electron-hole pairs are created, which upon recombination produce photons as described above. OLEDs are attractive for use in FPDs since they provide excellent display and viewing characteristics, can be manufactured on a flexible substrate (e.g. plastic), do not require high-temperature processing to dope them, and have fast element response times.
[0005] OLED FPDs are formed by etching an array of pixel elements into a substrate. In the array, portions of the active pixel elements, including thin film transistor (TFT) devices, storage capacitors and ITO patterns are formed on the substrate. The substrate is then coated with organic materials that form the light emitting portion (i.e. the diode) of the OLED. Further details concerning the manufacturing of OLED FPDs may be found in U.S. Pat. No. 5,688,551, which describes the first application of organic materials for OLED FPD manufacturing.
[0006] FIG. 1A shows a simplified diagram of a top view of a small six-column by four-row (6×4) OLED FPD 10 . FPD 10 comprises an array of pixel elements 100 , a row electrical driver 102 , and a column electrical driver 104 . During operation, if, for example, column electrical driver 104 activates column 3 and row electrical driver 102 activates row 2 , then the pixel shown in black in FIG. 1A will be activated and light emission from this particular pixel element will result. A side view of the OLED FPD 10 in FIG. 1A is shown in FIG. 1B . There, the various layers of the FPD can be seen, including substrate 106 , organic layer 108 , and metal layer 109 .
[0007] FIG. 1C shows a schematic diagram of a typical active pixel element 100 that is used in the OLED-FPD in FIGS. 1A and 1B . Pixel element 100 is formed by two TFT devices 110 and 112 , a storage capacitor 114 , and an LED 116 . TFT 110 acts like an analog electrical switch, which closes (i.e. turns ON) when the row selection signal 118 is active. Upon TFT 110 turning ON, the voltage present at column line 120 provides a charge source, which allows storage capacitor 114 to charge to a predetermined value. This charge is stored on storage capacitor 114 , until a subsequent writing cycle corresponding to the display frame rate. As alluded to above in the discussion of non-organic LED pixel elements, this method of energizing a display pixel is referred to as “active”, due to the presence of TFT 110 —an electronically active element. Active pixel elements are not unique to OLED FPDs. Indeed, for more information concerning active FPDs, reference may be made to the book “Color TFT Liquid Crystal Displays,” T. Yamasaki et al., edited by SEMI Standard FPD Technology Group, 1996.
[0008] FIG. 1D shows how the luminance of pixel element 100 is controlled. As shown, a voltage Vs present on storage capacitor 114 controls the transconductance (Gm) of TFT 112 . A variation in Gm causes a variation in the current Id flowing into LED 116 and, consequently, the light emission luminance of LED 116 . In essence, TFT 112 behaves like an electrically isolated voltage controlled current source in response to the voltage value Vs.
[0009] Turning now to the topic of defects in FPDs, it is well known that vast majority of defects in FPDs are found in the active plates of the FPDs. Because of this, during the manufacturing of FPDs, the active plates are typically tested prior to finally assembling the displays. By testing prior to final assembly, pixel defects can be detected early in the display manufacturing process, thereby resulting in a reduction in production costs.
[0010] Defects also commonly arise in the active plate of OLED displays. Accordingly, it would be desirable to test the active plates used in OLED displays prior to final assembly (e.g. prior to application of organic layer 108 and metal layer 109 ) as well. This desire is increased when it is recognized that organic layer 108 contributes substantially to the total display manufacturing costs. Besides material costs, a primary reason for the high cost is that atmospheric sealing methods must be employed to protect currently available organic emissive layers. Without proper protection from the atmosphere, the expected lifetime of organic layers can be substantially compromised. For more information on this topic, see the article “Microdisplays Based Upon Organic Light-Emitting Diodes,” W. E. Howard, et al., IBM J. RES. & DEV., vol. 45 no. 1, January 2001.
[0011] Unfortunately, testing the active plates prior to applying the organic and metal layers presents significant challenges since each pixel element output is in essence electrically floating, as shown schematically in FIGS. 2A and 2B . Specifically, FIG. 2A shows a top view of the OLED FPD plate prior to it being coated with the organic and metal layers 108 and 109 in FIG. 1A , and FIG. 2B shows that, because LED 116 is absent, each pixel element 100 is essentially a floating pixel element (fpe), i.e., an open electrical circuit.
SUMMARY OF THE INVENTION
[0012] Methods of and apparatus for detecting pixel element defects in flat panel display (FPDs) are disclosed. Floating pixel elements (fpes) of uncompleted active plates in a manufacturing process are activated with a high frequency test signal. In response to the activation signal, a high frequency output signal is produced by a voltage divider formed by an impedance of the fpe under test and an impedance presented by high frequency elements (e.g. stray capacitances) associated with the fpe under test. A signal characteristic (e.g. the amplitude) of the output signal is compared to an expected characteristic to determine the presence of pixel element defects. The methods of the present invention may be performed prior to completion of the active plate, e.g., prior to forming a liquid crystal between plates of a passive matrix LCD and prior to coating a partially formed OLED active plate with light emitting organic material layers. Use of high frequency activation signals allows detection of pixel element defects that are invisible to DC test methods. Additionally, because the methods and apparatus of the present invention allow testing prior to FPD plates being completely manufactured and prior to FPD final assembly, pixel defects can be detected early in the display manufacturing process, thereby resulting in a substantial reduction in production costs.
[0013] Further aspects of the invention are described and claimed below, and a further understanding of the nature and advantages of the inventions may be realized by reference to the remaining portions of the specification and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1A shows a simplified diagram of a top view of a small, six-column by four-row (6×4) OLED FPD;
[0015] FIG. 1B shows a side view of the OLED FPD in FIG. 1A ;
[0016] FIG. 1C shows a schematic diagram of a typical active pixel element used in the OLED FPD in FIGS. 1A and 1B ;
[0017] FIG. 1D shows how the luminance of a pixel element in the OLED FPD in FIGS. 1A and 1B is controlled;
[0018] FIG. 2A shows a top view of an OLED FPD plate prior to it being coated with an organic material and other layers, thereby giving rise to a floating pixel element (fpe);
[0019] FIG. 2B shows a schematic diagram of an fpe of the OLED FPD in FIG. 2A ;
[0020] FIGS. 3A-3C show three examples in which the equivalent impedance Z of a floating pixel element has a value equal to, less than, and greater than a nominal impedance value Zo;
[0021] FIG. 4A shows a block diagram of a pixel testing apparatus, according to an embodiment of the present invention;
[0022] FIG. 4B shows a block diagram of a specific, exemplary synchronous detector that may be used to detect the amplitude of the output signal Vo′ generated by the pixel testing apparatus in FIG. 4A ;
[0023] FIGS. 5A and 5B show a prior art passive matrix LCD FPD, which has row and column glass plates etched with rows and columns of indium tin oxide (ITO);
[0024] FIG. 6A shows a representative example of a thin LCD glass plate having nine columns etched with ITO;
[0025] FIG. 6B shows that, in the absence of a liquid crystal, each ITO column of the LCD glass plate in FIG. 6A is floating with respect to its activation voltage contacts (V 1 though V 9 ) and its reference voltage potential (ground);
[0026] FIG. 6C shows a distributed network model that may be used to represent high frequency elements (e.g. stray impedances) and be used as an accurate model the LCD glass plate, including the fpes, in FIG. 6A ;
[0027] FIG. 7A shows test results when a column plate, such as a column plate of the LCD plate in FIG. 6A , is measured using a DC test signal;
[0028] FIG. 7B shows test results when a column plate, such as a column plate of the LCD plate in FIG. 6A , is measured using the test methods described in connection with the test apparatus shown in FIG. 4 , according to an embodiment of the present invention;
[0029] FIG. 7C shows a conduction network model of the LCD plate in FIG. 6A obtained from a careful electrical measurement using a sensitive mechanical contact electrical multimeter and adjacent column capacitance calculations taking into account plate geometries;
[0030] FIG. 7D shows a theoretical solution of the conduction network in FIG. 7C when a DC test signal is used as the activation signal;
[0031] FIG. 7E shows a theoretical solution of the conduction network in FIG. 7E when an AC test signal is used as the activation signal, according to an embodiment of the present invention;
[0032] FIG. 8A shows a high frequency equivalent circuit of floating pixel element (fpe) of an uncompleted OLED FPD plate, with a high frequency signal Va superimposed on a DC bias signal Vdd, according to an embodiment of the present invention;
[0033] FIG. 8B shows a simplified equivalent circuit model of the fpe test setup in FIG. 8A , according to an embodiment of the present invention;
[0034] FIG. 8C shows a further simplified equivalent circuit model of the fpe test setup in FIGS. 8A and 8B , according to an embodiment of the present invention;
[0035] FIG. 8D shows a graph of an exemplary calculation of the expected amplitude of Vo, for several values of the inverse of the transconductance Gm, when a high frequency activation signal Va is applied to the Vdd line of the fpe in FIGS. 8A-8C , according to an embodiment of the present invention;
[0036] FIG. 8E shows two, two-dimensional (2-D) maps of hundreds of spatially adjacent measurements of a plurality of fpes of an OLED FPD plate, made using the methods and apparatus of the present invention;
[0037] FIG. 9A shows a high frequency equivalent circuit of floating pixel element (fpe) of an uncompleted OLED FPD plate, with a high frequency signal Va superimposed to the Vcs line of the fpe, according to an embodiment of the present invention;
[0038] FIG. 9B shows a simplified equivalent circuit model of the fpe test setup in FIG. 9A , according to an embodiment of the present invention;
[0039] FIG. 9C shows a further simplified equivalent circuit model of the fpe test setup in FIGS. 9A and 9B , according to an embodiment of the present invention; and
[0040] FIGS. 10A-10E show various examples of testing sequences of OLED substrate plates that may be applied, according to embodiments of the present invention.
DETAILED DESCRIPTION
[0041] Embodiments of the present invention are described herein in the context of testing uncompleted FPDs. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. Unless indicated otherwise, the same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.
[0042] In some types of FPDs, such as, for example, passive matrix LCDs and passive or active matrix OLED displays, at least one of the plates contain pixel elements during the manufacturing process that exhibit an open circuit condition at the intended frequency of operation or lower. For example, as discussed above, prior to coating the substrate with the organic material layers during the manufacture of an OLED FPD, the absence of the LED renders the pixel elements of the display as open circuits. In accordance with embodiments of the present invention, alternating current (AC) activation signals, of a frequency greater than, for example, the frequency of operation of an OLED FPD are applied to detect variations possibly corresponding to pixel element defects.
[0043] FIGS. 3A-3C show three examples in which the equivalent impedance Z of a floating pixel element has a value equal to, less than and greater than a nominal value Zo. According to embodiments of the present invention, the impedance Z of a given pixel element can be measured by applying an AC activation signal Va and measuring the amplitude of a voltage Vo provided by the voltage divider formed between the impedance presented by the pixel element and the impedance presented by stray capacitances associated with the pixel element. The stray capacitances are induced by a complex interaction of adjacent pixel elements, row and/or column activation lines and other parasitic capacitances to ground potential. According to embodiments of the invention, at a sufficiently high activation frequency, the floating pixel elements become electrically closed to ground potential. Hence, a variation on the pixel element equivalent impedance Z, which could correspond to a pixel element defect, can be measured.
[0044] The stray capacitances encountered in the active plates of FPDs can be extremely low. Accordingly, it is necessary to measure the amplitude of the signal output using a very high input impedance measuring instrument, so that the instrument itself does not affect the measurement. According to an embodiment of the invention, one such instrument that can be used is the electron beam probe, which in practice provides nearly infinite input impedance. The basic operation of the electron beam probe is very well described in the available prior art literature and will not be explained in detail here. Reference may be made to, for example, U.S. Pat. Nos. 6,075,245 and 5,982,190 by the same inventor, both of which disclose systems and methods for testing FPD arrays using electron beams.
[0045] Referring to FIG. 4A , there is shown a block diagram of a pixel testing apparatus 40 , according to an embodiment of the present invention. As shown, an electron beam (“e-beam”) 400 is directed at a floating pixel element (fpe) 402 such that secondary electrons (SE) are emitted from the fpe's surface. To obtain the highest possible sensitivity of voltage measurement the energy of e-beam 400 may be adjusted to a value that matches the optimum beam energy for the substrate and/or other materials being irradiated. The optimum beam energy value is achieved when no charging occurs, which can cause significant voltage measurement errors. For example, for a glass substrate, the optimum beam energy is on the order of about 2 keV and for polymer/plastic substrates the optimum energy is on the order of about 400 eV. For detailed information on this subject reference is made to the book “Scanning Electron Microscopy and X-Ray Microanalysis,” J. Goldstein et al., Plenum Press, 1992, which is hereby incorporated by reference.
[0046] Floating pixel element 402 is activated with at least one high frequency signal Va provided by an AC signal generator 403 . The generated SE are collected by an electron detector 404 and amplified. An output signal Vo′ of electron detector 404 is a signal that corresponds to Vo, which is a signal that results from voltage dividing the input activation waveform Va between the equivalent pixel impedance Z of fpe 402 and the associated impedance of stray capacitance Cst. Output signal Vo′ of electron detector 404 is fed into an amplitude or envelope detector 406 . Detector 406 may be any one of several types of detectors, such as, for example, a peak-to-peak detector, a synchronous detector, or a matched filter. FIG. 4B shows a block diagram of a specific exemplary synchronous detector that may be used. This synchronous detector operates similarly to the electronic circuit used in radio frequency AM demodulation. It comprises an analog multiplier 408 , which provides the product of the incoming signal Vo′ and an image of the display activation signal Va′. Depending on any time delay generated during the transfer of the signal Va through the panel and to the output of the electron detector, the image of the display activation signal Va′ may need to be electronically delayed in the same proportion to provide optimum detection operation. The output of multiplier 408 is fed into a low pass filter 410 , which provides an output having the desired amplitude or envelope properties of the signal Vo′. For a detailed description of the theory of operation of a synchronous detectors of this type refer to, for example, “Introduction to Communication Systems,” F. G. Stremler, Addison-Wesley Publishing Company, 1982. Whereas specific exemplary embodiments of what may be used to detect the amplitude or envelope of output signal Vo′ have been provided, those of ordinary skill in the art will readily appreciate that other methods and apparatus for detecting the amplitude or envelope properties of output signal Vo′ may be used.
[0047] Referring now to FIGS. 5A and 5B , there is shown a prior art passive matrix LCD FPD 50 . LCD FPD 50 comprises row and column glass plates 500 and 502 , each of which are etched with patterns of rows 504 and columns of 506 of indium tin oxide (ITO), or other transparent electrical conductor, and a liquid crystal material 508 disposed between the row and column plates 500 and 502 . A display pixel is formed at the intersection of each row and column 504 and 506 . During operation, a pixel is activated by applying appropriate row and column drive signals from a row electrical driver 510 and a column electrical driver 512 . For example, in the representative example of a small six-column by four-row (6×4) display shown in FIGS. 5A and 5B , the pixel shown in black is activated if the column electrical driver 512 activates column 3 and the row electrical driver 510 activates row 2 .
[0048] According to an embodiment of the present invention, the electrical conduction characteristics of the rows and columns 504 and 506 of plates 500 and 502 may be tested prior to be assembled into a complete display containing the liquid crystal, polarizers and other components. FIG. 6A shows a representative example of a thin LCD glass plate 60 having nine columns etched with ITO. In the absence of the liquid crystal, and at the normal frequency of operation of the LCD, each ITO column should be floating with respect to its activation voltage contacts (V 1 though V 9 ) and its reference voltage potential (ground), as is shown schematically in FIG. 6B . This floating condition is indicated by the label “fpe” (i.e. floating pixel element) in FIG. 6A . At higher activation frequencies, however, the simple electrical model of FIG. 6B becomes less of an accurate representation of the electrical characteristics of plate 60 . One reason for this is that, at higher frequencies, impedances of stray capacitances and other parasitic elements must be accounted for, but are not in the model of FIG. 6B . To represent these high frequency elements, a distributed network model, like that shown in FIG. 6C , may be used. According to this model, each column presents impedances connected to the voltage sources, adjacent columns and ground potential. Unexpected values of these impedances may be the consequence of, among other reasons, ITO conductor defects such as open circuits and shorts, bad electrical connections, ITO material uniformity variations, adjacent column proximity capacitances, and stray capacitances to ground potential through the glass substrate.
[0049] FIGS. 7A-7E compare test results when a column plate, such as a column plate of LCD plate 60 in FIG. 6A , is measured using a DC test signal to test results collected when using the test methods described in connection with the test apparatus shown in FIG. 4A , according to an embodiment of the present invention. Specifically, FIG. 7A shows test results for the case where the plate is activated by a DC signal, whereas FIG. 7B shows test results using the apparatus and methods of the present invention. For the test results shown, the activation frequency is set at 2.5 Mhz. However, those skilled in the art will readily understand that other activation frequencies may be used. Additionally, for simplicity, a DC test signal of Va=10 V DC was applied to each column in the DC test case, and a sinusoidal AC test signal of Va=+/−10 V AC was applied to each column in the AC test case. The top portions of FIGS. 7A and 7B show a two-dimensional data map of hundreds of very closely spaced electron probe measurements. Lighter shades in the maps indicate higher detected voltages, and darker shades in the maps indicate lower detected voltages. The measurement area corresponds to the area S depicted in FIG. 6A . FIGS. 7A and 7B also show numerical graphs of the average of the measured values for each column. The results obtained with both methods show significant differences. Whereas both approaches reveal that columns 5 and 8 have severe conduction defects, only the approach using the methods and apparatus of the present invention is capable of revealing additional defects. A careful electrical measurement using a sensitive mechanical contact electrical multimeter and adjacent column capacitance calculations taking into account plate geometries, resulted in the conduction network shown in FIG. 7C , where each column is represented by the nodes U 1 though U 9 , respectively. Careful analysis of plate 60 revealed that the reasons of the conduction defects were improper electrical and wiring connections that caused both a decrease in the conduction of each column and resistive or capacitive shorts to ground potential. The theoretical solution of the network for the cases of a DC and a 2.5 MHz activation signal Va are shown in FIGS. 7D and 7E , respectively. It indicates a good agreement with the measured results shown in FIGS. 7A and 7B . The differences between the measured and the theoretical values are attributable to topographical feature influences and other nonlinearities due to less than ideal implementations of the voltage contrast detection method. Nevertheless, the general correspondence between the experimental and theoretical values confirm that the apparatus and methods of the present invention can be used to detect conduction defects of floating element FPD plates that are otherwise invisible to standard DC measurement methods.
[0050] The test methods described above in connection with the test apparatus shown in FIG. 4 may be used to test the active plate of an uncompleted OLED FPD, according to an embodiment of the present invention. FIG. 8A shows a high frequency equivalent circuit of floating pixel element (fpe) of an uncompleted OLED FPD plate, with a high frequency signal Va superimposed on a DC bias signal Vdd, according to an embodiment of the present invention. The terminal of the yet-to-be-assembled OLED, shown schematically in FIGS. 8A-8C as a shaded square 800 , may be coupled, via stray capacitances, to, for example: ground, via the underside of the substrate (assuming that the substrate is above and in closed contact to a ground plane (Csb) 802 ); the Vdd power signal line, which typically runs in close proximity to the pixel element (Cv) 804 ; and the column activation signal S which also typically runs in close proximity to the pixel element (Cs) 806 . Those skilled in the art will understand that other arrangements may exist depending on, for example, the particular materials used, electrical circuit design, semiconductor layout, etc. For example, the stray capacitance 802 could be of a significantly larger value if the OLED substrate is made of a very thin plastic/polymer material instead of the typically used and relatively thick glass substrate. FIG. 8A also shows the parasitic capacitances of both TFT 808 and TFT 810 , which, although relatively smaller, may in some cases affect the overall capacitive behavior of each pixel element.
[0051] It should be emphasized here that the fpe shown in FIG. 8A and other figures of this disclosure is but one of a variety of pixel element types that may be tested using the methods and apparatus of the present invention. For example, whereas the fpe in the FIG. 8A and the figures referred to below is shown as being connected in a current source mode, with a p-channel current controlling transistor 810 , those skilled in the art will readily understand that other pixel element types may be tested. For example, a different pixel element might use an n-channel current controlling transistor, instead of the p-channel current controlling transistor 810 in the fpe in FIG. 8A . In such a case, the diode would be repositioned between Vdd and the drain of the n-channel transistor, rather than between drain of p-channel transistor 810 and ground. It must also be noted that the storage capacitor terminal Vcs shown in FIG. 8A , which is typically directly connected to either Vdd or ground depending of the current controlling transistor channel type (i.e. connected to Vdd for a p-channel transistor or to ground for an n-channel transistor), may be in some applications connected to an intermediate DC value. Also, the “ground” potential, as referred to above, could be of an absolute negative value with respect to Vdd. Accordingly, those skilled in the art will readily understand that other pixel element configurations, using different transistor types (i.e. n-type or p-type) and arrangements, and related positionings of the diode and the Vcs terminal, may be tested by obvious adjustments to bias, transistor connections, and to the manner in which control, test and other signals are input to and output from the fpe under test. It should also be pointed out that, for purposes of this disclosure, the words source and drain of the transistors described in this disclosure will be viewed and treated as being interchangeable.
[0052] FIG. 8B shows an equivalent circuit model of the floating pixel element for high activation frequencies, according to an embodiment of the present invention. According to this circuit model, all stray capacitances and the impedance effects of TFT 810 are lumped into two equivalent impedances—the first, Z 1 , which is coupled to ground and the second, Zo, which is coupled to the to the activation source Va. The impedance Zo is variable and changes as a function of the control voltage Vs. In its most simple form, the equivalent impedance model for each fpe can be represented as shown in FIG. 8C . In that example, Zo has been replaced with a voltage controlled variable conductance model of TFT 810 in parallel with a resultant stray capacitor Co.
[0053] Optimum selection of the activation frequency of activation signal Va depends on the values of the stray capacitances present in the particular design of the OLED plate. FIG. 8D shows a graph of an exemplary calculation of the expected amplitude of Vo for several values of the inverse of the transconductance Gm, when a high frequency activation signal is applied to the Vdd line as shown in FIG. 8C . The stray capacitances Co and Cl are assumed to have the same value of 5 femtofarads (5×10 −15 farads), the values of which were obtained from approximated geometrical calculations and electrical measurements of the AC load presented to the activation signal generator. These very small stray capacitance values justify the selection of an electron beam probe as the preferred measuring instrument for testing OLEDs. However, in some cases care must be taken such that the electron beam specimen current induced into the sample is of a sufficiently low value that it does not externally charge any stray capacitance. It has been determined that at optimum beam energy and typical stray capacitances values, a beam current of 5 nA or less will not significantly affect a high frequency voltage measurement. However, it is possible than in some cases a relatively high electron beam specimen current could be beneficial and could contribute in achieving a better or a faster measurement by using the electron beam to externally charge any of the OLED pixel elements' stray capacitances.
[0054] According to another embodiment of the invention, it may also be desirable to test each pixel element at the range of transconductances encountered during normal operation of the finished OLED display. In a typical case the current Id required to activate the OLED to full scale light emission is in the range of 10 μA with a required minimum gray level requirement of 1/64 times or less. For a Vdd value of 10 V, that range corresponds to 1/Gm values ranging from approximately 930 kΩ to 59 MΩ. From FIG. 8D , it is observed that activation frequencies ranging from about 2 to 10 Mhz will provide acceptable measurement ranges of such transconductances. As was pointed out previously, the graphs shown in FIG. 8D will depend on the values of the stray capacitances Co and Cl. In general terms, a simultaneous increase of both capacitances will tend to shift the 1/Gm curves to the left of the graph (lower frequencies) and a decrease to the right (higher frequencies), while a variation of Cl with respect to Co will vary the minimum obtainable Vo/Va ratio (0.5 in the example shown FIG. 8D ). FIG. 8E shows two, two-dimensional (2-D) maps of hundreds of spatially adjacent measurements of a plurality of fpes of an OLED FPD plate, made using the methods and apparatus of the present invention. The measurements were taken with an activation frequency of 2.5 MHz and at two arbitrary values of Vs. The maps show defective column defects characterizing what appear to be unusual levels of high and low conductances with respect to the neighboring pixel elements. The top 2-D map was obtained with a Vs value that corresponded to a higher TFT 810 conductance and the bottom one to a lower. Both 2-D map images have been contrast-stretched for better printing quality purposes.
[0055] According to an alternative embodiment of the invention, it may be possible to achieve similar results, as to those already described, by applying a high frequency signal to the Vcs line, rather than to the Vdd line. This approach is shown schematically in FIG. 9A . According to this approach, the voltage that controls the transconductance of TFT 810 could be composed of a high frequency AC component added to a DC signal. The AC component will cause a high frequency modulation of the impedance Zo (see FIG. 9B ), which in the simplified electrical model, corresponds to a modulation of the 1/Gm impedance value ( FIG. 9C ). This causes a high frequency variation of the amplitude of the waveform Vo present on the floating pixel element. This waveform amplitude can also be measured using the methods and apparatus of the present invention described above. An advantage of this alternative approach is that both the S and G activation lines could remain inactive (TFT 808 switch permanently in its off state), thereby providing for a potentially faster and a more controlled method for testing the transconductance of TFT 810 . Also, by eliminating the need for activation of the G and S lines and other related signals, the required electrical contact probing complexity could potentially be reduced, thereby providing substantial cost reduction benefits.
[0056] FIGS. 10 A-E shows some examples of testing sequences applied to an OLED plate having fpes similar to the fpe shown in FIG. 8 , according to embodiments of the present invention. In these particular examples, it is assumed that the current controlling transistor T 2 is a p-channel type and is operating in current source mode (i.e. its source terminal connected to Vdd and the drain to the OLED fpe), that the storage capacitor terminal Vcs is connected to Vdd, and that the control transistor T 1 is an n-channel type. Those skilled in the art will readily understand that the biasing and test signal characteristics may need to be modified to test other pixel element types. For example, in the case of a p-channel control transistor, the gate voltage signal G will be inverted with respect to the ones shown in FIGS. 10 A-C. For clarity, the figures show only the high frequency AC activation signals and not the DC components, which have been replaced with dotted lines.
[0057] FIG. 10A shows a method for testing an overall Go-No-Go performance. At t=0, the amplitude of Vo is measured for testing an OFF state condition. Immediately the pixel element is fully activated ON. At t=T 1 , the amplitude of Vo is measured for testing an ON state condition. A period corresponding to one frame rate, for example, 16.7 ms, is waited, and at t=T 2 the amplitude of Vo is measured again to test for a leakage defect condition. A pixel is considered to have passed the Go-No-Go test only if all three measurements fall within acceptable predefined ranges.
[0058] FIG. 10B shows a method for testing the transconductance Gm. The pixel is activated to a predetermined value and at t=T 1 the amplitude of Vo is measured. Then the pixel is activated to a second predetermined value, and at t=T 2 the amplitude of Vo is measured again. The delta of variations gives an indication of Gm.
[0059] FIG. 10C shows a method for testing the channel or drain conductance (Gd). The pixel is activated to a predetermined value, and at t=T 1 the amplitude of Vo is measured. Then, the pixel is activated to the same predetermined value as before, but the amplitude of the high frequency signal in Vdd is varied to a second value. At t=T 2 the amplitude of Vo is measured again. The delta of variations gives an indication of Gd.
[0060] FIG. 10D shows a method for testing the transconductance Gm using the alternative approach shown in FIG. 9 . The Vcs line is activated with a high frequency signal of a predetermined amplitude, and at t=T 1 the amplitude of Vo is measured. Then, the amplitude of the high frequency signal in Vcs is varied to a second value, and at t=T 2 the amplitude of Vo is measured again. The delta of variations gives an indication of Gm.
[0061] FIG. 10E shows a method for testing the channel or drain conductance Gd using the alternative approach shown in FIG. 9 . The Vcs line is activated with a high frequency signal of a predetermined amplitude, and at t=T 1 the amplitude of Vo is measured. Then, Vcs is activated with a high frequency signal at the same predetermined amplitude, but Vdd is varied to a second value. At t=T 2 the amplitude of Vo is measured again. The delta of variations gives an indication of Gd.
[0062] The foregoing detailed description describes methods of and apparatus for testing unfinished FPD plates, according to various embodiments of the present invention. Whereas the description is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. For example, whereas the design implementation of the pixel element driving circuit shown in FIG. 8A is shown to comprise only a single TFT, the methods and apparatus of the present invention can just as well be applied to other pixel element driving circuit arrangements. For an example of another method of driving an OLED pixel element, refer to the publication “P-103: Novel Poly-Si TFT Pixel Electrode Circuits and Current Programmed Active-Matrix Driving Methods for AM-OLEDs”, Y. Hong et. al., SID 02 Digest. According to this method, Hong describes an arrangement of four TFTs for each pixel element, two of which provide the driving current to the OLED. Hence, those skilled in the art will readily understand that the basic principles of the present invention extend to other pixel elements having different pixel driving circuitry. Additionally, whereas the disclosure describes an OLED structure for an FPD in which light is emitted through the substrate in a down-emitting stack configuration, and where the floating pixel elements are formed with an ITO layer etched into the substrate, which allows the light to pass through it and a transparent substrate, the invention is applicable to other types of OLED structures. For example, the testing methods and apparatus may also be used to test plates of an OLED structure in which light is emitted in an up-emitting manner. According to this structure, the floating pixel elements are formed with a nontransparent metallic layer etched into the substrate causing light emission though a ITO layer located above the OLED layers. Hence, one skilled in the art would find it is obvious that the present invention is also applicable to the case of an up-emitting stack, in which case the floating pixel elements are made of a metallic layer instead of ITO. For these and other reasons, therefore, the above description should not be taken as limiting the scope of the invention as it is defined by the appended claims. | Methods of and apparatus for detecting pixel element defects in flat panel display (FPDs). Floating pixel elements (fpes) of uncompleted active plates in a manufacturing process are activated with high frequency AC test signals. In response to the activation signal, a high frequency output signal is produced by a voltage divider formed by an impedance of the fpe under test and an impedance presented by high frequency elements (e.g. stray capacitances) associated with the fpe under test. A signal characteristic (e.g. the amplitude) of the output signal is compared to an expected characteristic to determine the presence of pixel element defects. The methods of the present invention may be performed prior to completion of the active plate, e.g., prior to forming a liquid crystal between plates of a passive matrix LCD and prior to coating a partially formed OLED active plate with light emitting organic material layers. Use of high frequency activation signals allows detection of pixel element defects that are invisible to DC test methods. Additionally, because the methods and apparatus of the present invention allow testing prior to FPD plates being completely manufactured and prior to FPD final assembly, pixel defects can be detected early in the display manufacturing process, thereby resulting in a substantial reduction in production costs. | 6 |
This application is a continuation of application Ser. No. 07/418,828 filed, Oct. 4, 1989, which is a continuation of application Ser. No. 07/-094,894 filed Sept. 10, 1987, both now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording apparatus, and in particular to an impact type recording apparatus which effects recording by the impact force of a recording hammer.
2. Related Background Art
In the field of a recording apparatus for a computer system or an electronic typewriter, there is generally known a so-called impact type recording apparatus such as a daisy wheel printer. The recording apparatus of this type is designed chiefly such that a hammer or the like is driven by a magnetic force produced when electric power is supplied to a solenoid, and impacts characters to thereby accomplish printing, and such recording apparatus has the merit that printing of high quality can be obtained, while it has the demerit that the noise during printing is great. One of the causes of the noise is the impact sound produced when the hammer returns to its standby position and strikes against a stopper after printing. A method of reducing such noise is to supply electric power to the solenoid when the hammer returns to a predetermined position, and reduce the return speed thereof to thereby reduce the sound of impact against the stopper.
Generally, however, the areas of the characters included in the character wheel differ from one another and the printing energy necessary for printing also differs from character to character and therefore, the power supply time or the energizing current value of a coil unit for driving the hammer is controlled to thereby control the kinetic energy imparted to the hammer. For example, control is effected such that the hammer speed when printing a character of large printing area such as "M" is fast and the hammer speed when printing a symbol of small printing area such as "." is slow.
Therefore, in situations where an attempt is made to decelerate the printing hammer by the aforedescribed method and the energization timing is set so that as shown in FIG. 7A of the accompanying drawings, the deceleration is completed the hammer returns to the stopper. The deceleration corresponds to a curve 60 showing the displacement of the hammer when printing "M". The timing of the energization for deceleration will become too early in the case of a curve 61 which shows the printing of ".", and the brake will act before the hammer returns to the stopper, and thus the hammer will advance toward the platen (the portion indicated by 62). Also, if as shown in FIG. 7B of the accompanying drawings, the energization timing is set correspondingly to a curve 63 which shows the printing of ".", when the character "M" is printed, the hammer strikes against the stopper at 65 before it is decelerated as indicated by a curve 64, and thus a sufficient effect cannot be obtained.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an impact type recording apparatus in which the impact sound during the return of hammer means is reduced.
Other objects of the present invention will become apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross-sectional view showing the structure of the printing section of a printer according to an embodiment of the present invention.
FIG. 1B is a rear view of a hammer.
FIG. 1C is an enlarged view of a slit plate and a sensor portion.
FIG. 2 is a block diagram of the printer according to the present embodiment.
FIG. 3 shows the relation between the displacement of the hammer and the sensor output voltage.
FIG. 4 is a timing chart of the hammer control in the present embodiment during the printing of a character of high printing pressure.
FIG. 5 is a timing chart of the hammer control in the present embodiment during the printing of a character of low printing pressure.
FIGS. 6A and 6B are flow charts showing the hammer re-energization control of the control unit.
FIGS. 7A and 7B show the hammer displacement and the re-energization timing in an example of the prior art.
FIG. 8 is a block diagram showing the construction of a recording apparatus according to another embodiment of the present invention.
FIG. 9A is a flow chart showing the brake control procedure in said another embodiment.
FIG. 9B is a timing chart of the brake operation.
FIGS. 10A-10C show the hammer energizing current control when the return speed of the printing hammer is fast as when a character "M" is printed.
FIGS. 11A-11C show the hammer energizing current control when the return speed of the printing hammer is slow as when a symbol "." is printed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Some embodiments of the present invention will hereinafter be described in detail with reference to the drawings.
Description of a Printer shown in FIG. 2
FIG. 2 is a schematic block diagram showing the construction of a printer according to an embodiment of the present invention.
In FIG. 2, reference numeral 100 designates a controller for controlling the entire printer. The controller 100 includes an MPU such as a microprocessor, an ROM storing therein the control program, data, etc. of MPU shown in the flow chart of FIG. 6, an RAM as the work area of the MPU, etc. Reference numeral 101 denotes a hammer for impacting a character wheel rotated by a wheel drive motor 103 and effecting printing, and reference numeral 102 designates a hammer drive circuit for driving the hammer 101 by a magnetic force.
Reference numeral 103 denotes a wheel drive motor for rotating the character wheel to select a desired character on the character wheel, and reference numeral 104 designates a motor drive circuit for the wheel drive motor. Reference numeral 12 denotes a sensor for detecting movement of the hammer 101. The sensor 12 is used to detect the position and speed of movement of the hammer 101. The signal from the sensor 12 is shaped by a signal shaping circuit 510 and input as the sensor output signal to the controller. Reference numeral 106 designates a carriage drive section including a carriage drive motor or the like for moving a carriage, and reference numeral 107 denotes a paper advancing section including a paper advancing motor or the like. Reference numeral 108 designates a ribbon drive motor for effecting take-up driving of a printing ribbon, and reference numeral 109 denotes a time for counting time on the basis of the signal from the controller 100.
Description of the Printing Section of the Printer shown in FIGS. 1A-1C and FIG. 37
FIG. 1A is a cross-sectional view of the printing section of the printer according to the present embodiment.
The hammer 101 comprises an armature 101 - 1 formed of a magnetic material and a tip end portion 101 - 2 formed of a non-magnetic material. The hammer 101 is supported by a bearing 10 and the bearing portion of the support frame 7 of a coil unit 15 and is movable in the direction of arrow 9. The hammer 101 is normally pressed against the stopper 8 - 1 of a hammer base 8 by the force of a compression coil spring 16 and held in a so-called standby position.
The character wheel 2 mounted on the shaft of the wheel drive motor 103 fixed to the carriage 5 is rotated by the wheel drive motor 103, whereby a desired character is selected and carried to between the hammer 101 and a platen 1. Thereafter, when an electric power is supplied to the coil unit 15, the hammer 101 is protruded toward the platen 1 by a magnetic force produced between a yoke 6 and the armature 101 - 1, and impacts a character 2 - 1 against a recording medium 4 on the platen 1 through an ink ribbon 17, thus effecting printing. After the printing, the hammer 101 is retracted backwardly by the reaction force of the compression coil spring 16, and strikes against the stopper 8 - 1, whereby it is stopped and restores the standby position.
FIG. 1B shows a portion of the hammer 101 as seen from behind the stopper 8.
As shown in FIG. 1C, a slit plate 11 is attached to the hammer 101 and is moved with movement of the hammer 101. FIG. 1C shows the details of the sensor portion. The slit plate 11 is provided with slits 110-113. The displacement of the respective slits from the sensor 12 in the standby position is indicated at 120-124.
When the hammer 101 is reciprocally moved, a sensor output signal 20 as shown in FIG. 3 is input from the sensor 12 to the controller 100. The curve 21 of FIG. 3 shows the displacement of the hammer 101 for time, i.e., the distance thereof from the stopper 8 - 1. The output signal 20 of the sensor 12 is such a signal that assumes a high level during the light interception by the slit plate 11 and assumes a low level before the slit plate 11 passes or when the slits 110-113 pass.
Designated by 22 is the output signal during the so-called forward movement in which the hammer 101 arrives at the printing position 24 from the standby position, and denoted by 23 is the output signal during the so-called backward movement in which the hammer 101 returns from the printing position to the standby position. Also, designated by 25 is the displacement of the hammer 101 repelled by the stopper 8 - 1 after having struck against the stopper 8 - 1.
The width of and the spacing between the slits 110-113 are constant and therefore, if the time interval of the pulses of the sensor output signal 20 is read, the average speed of the hammer 101 during the meantime can be detected. Also, if the positional relations among the stopper 8 - 1, the sensor 12 and the slits 110-113 are predetermined, the position of the hammer 101 relative to the stopper 8 - 1 can be detected.
Description of the Decelerating Process of the Printing Hammer shown in FIGS. 4-6
The present embodiment adopts a method whereby the hammer 101 is re-energized correspondingly to the return speed thereof and the speed at which the hammer strikes against the stopper 8 - 1 is reduced. This operation will hereinafter be described in detail.
FIG. 4 shows the waveform when the speed of the hammer 101 printing a character of large printing area such as "M" as previously described is fast.
In FIG. 4, reference numeral 40 designates a waveform showing the spacing (displacement) between the stopper 8 - 1 and the hammer 101, and reference numerals 120-124, as in FIG. 1C, show the passage distances of the slit plate 11 relative to the sensor 2. Reference numeral 45 denotes the output signal of the sensor 12, and reference numerals 110-113 designate the output voltages of the sensor 12 1(corresponding to the positions of the slits 110-113.
When an instruction is given to print a character of large printing area such as "M", a large hammer energizing current is generated as indicated by 41 to energize the hammer 101. Thus, there is provided a steep rising waveform as shown by a waveform 40 and it is seen that the hammer 101 has been driven at a high speed. The return speed of the hammer 101 is found on the basis of the passage time 42 between the slits 112 and 111 (the passage time through the spacing between positions 122 and 123) when the hammer 101 returns after having arrived at the printing position.
When the edge of the slit 111 is detected at time T1, the hammer 101 is re-energized by a pulse 43 after time tl and the return speed of the hammer 101 is reduced. Thus, the shock with which the hammer 101 returns to the stopper 8 - 1 at 44 is reduced, whereby noise is reduced. This delay time tl is determined correspondingly to the return speed of the hammer 101.
FIG. 5 shows the waveform when a symbol of small printing area such as "." is printed, that is, when the speed of the hammer 101 is slow.
In FIG. 5, reference numeral 50 designates a waveform showing a variation in the stopper 8 - 1 and the hammer 101, and reference numerals 120-124, as in FIG. 4, denote the passage distances of the slit plate 11 relative to the sensor 12, and the waveform of the output signal of the sensor 12 corresponding thereto is designated by 55. As can be seen from the comparison with FIG. 4, when a printing instruction is given, the hammer 101 is driven by a pulse 51 which is smaller than the pulse 41. Thus, the hammer 101 is driven at a speed slower than in the case of FIG. 4. As in the case of FIG. 4, the hammer arrives at the printing position and the return speed thereof is found on the basis of the passage time 52 between the slits 112 and 111 (the passage time through the spacing between positions 122 and 123) when the hammer returns.
When as in the case of FIG. 4, the edge of the slit 111 is detected at time T2 in this manner, delay time t2 is found on the basis of the passage time 52 (return speed) and at a time delayed by t2 with respect to the time T2, the hammer 101 is reenergized by a pulse 53 and the return speed of the hammer 101 is reduced. Thus, the speed at which the hammer 101 returns to the stopper 8 - 1 at 54 can be reduced with good timing.
If design is made such that the return speed of the hammer 101 is detected in this manner and the time at which the re-energizing pulse is generated is changed corresponding thereto, better deceleration can be accomplished. This control method is shown in the flow chart of FIG. 6.
FIGS. 6A and 6B are the flow charts of the decelerating process for reducing the return speed of the hammer 101 when printing is executed.
First, at step S1, the pulse counter PLSC of RAM is set to "0". Subsequently, at step S2, whether the pulse counter PLSC has been set to "7" is checked up. This pulse counter PLSC is counted up by the interruption process of FIG. 6B in synchronism with the rising of the pulse from the signal shaping circuit 110. Each time the pulse signal from the sensor 12 rises, the interruption process program shown in the flow chart of FIG. 6B is executed, and first, at step S10, whether the pulse counter PLSC is set to "5" is checked up. Until the pulse counter PLSC is set to "5", nothing particular is done in this interruption routine, and at step S15, tl is only effected in the pulse counter PLSC and at step S16, return is only made to the main routine. When the pulse counter PLSC is set to "5", advance is made to step S11 and timer 109 is started, whereupon time counting is started.
This corresponds to the position of the displacement 123 of the hammer 101 when it returns which is shown in FIGS. 4 and 5, and means the instruction to start the measurement of time 42 or 52. When at step S12, the pulse counter PLSC assumes "6", that is, the displacement of the hammer 101 becomes 122, advance is made to step S13, where the timer 109 is stopped, and at step S14, the counted time th of the timer 109 is read. This corresponds to the times 42 and 52 of FIGS. 4 and 5. Subsequently, at step S15, t1 is effected in the pulse counter PLSC, and at step S16, return is made to the main routine.
When the above-described interruption routine is executed and the lapse time th of the timer 109 is read, advance is made to the step S3 of FIG. 6A, and on the basis of the value of the time th, the output level (the energizing pulse width) of the hammer 101 is determined with reference to the table or the like of the ROM of the controller 100. At step S4, on the basis of the time th, the delay time is determined with reference to the table as at step S3. This delay time corresponds to the time tl or t2 shown in FIGS. 4 and 5, and represents a delay time with respect to the time T1 or T2 of the re-energizing pulses 43 and 53. At step S5, the timer 109 is set to that delay time, and at step S6, whether that time has elapsed is checked up. When the lapse of the delay time is confirmed by the output of the timer 109, re-energizing pulse is put out at step S7 and the return speed of the hammer 101 is reduced.
As described above, according to the present embodiment, the hammer 101 is endowed with a delay time corresponding to the return speed from a predetermined position in conformity with the return speed of the hammer 101 and re-energization of the hammer is effected for deceleration, whereby there is obtained a smooth deceleration effect corresponding to the return speed of the hammer 101.
The detection of the pulse output by the sensor output signal in the present embodiment may be effected at the rising or the falling of the pulse, and the counting of the delay time may be accomplished not only by the timer, but also by counting the pulse number from the sensor.
As described above, according to the present invention, the speed of the hammer during its return can be reduced in conformity with the speed of the hammer and therefore, deceleration can be achieved efficiently and smoothly and impact sound can be weakened.
Another embodiment of the present invention will now be described with reference to FIGS. 8 to 11. In the present embodiment, as compared with the previously described embodiment, the value of the hammer braking current, in addition to the hammer braking timing, can be varied in conformity with the detected speed of the hammer.
FIG. 8 is a block diagram showing the construction of a recording apparatus according to another embodiment of the present invention. In FIG. 8, reference numeral 300 designates a printing controller including a pulse forming circuit 301 for amplifying the detection signal from a sensor 212 and forming a pulse, a central processing unit (CPU) 302 for detecting the return speed or the like of a printing hammer 209 in response to the generation of a pulse signal by the pulse forming circuit and finding a solenoid drive starting position, a driving current, etc. for effecting appropriate hammer braking on the basis of said detected speed, and effecting the drive control of the printing hammer in accordance with these, and a peripheral IO circuit 304 for sending the control signal of the CPU 302 to the outside. Reference numeral 305 denotes a driver circuit for driving the printing hammer.
Operation will now be described.
FIGS. 10A-10C show the hammer energizing current control when the return speed of the printing hammer 209 is fast as when a character such as "M" is to be printed, and in this case, after the return speed is detected between B and D, re-energization is immediately effected by a pulse 229 so that smooth deceleration is accomplished as indicated by a curve 226.
FIGS. 11A-11C show the hammer energizing current control when the return speed of the printing hammer 209 is slow as when a symbol such as "." is to be printed. If re-energization is effected simultaneously with the speed detection between B and D as previously described also when a character of small printing area like a symbol "." is printed, brake will act at a location far from a stopper 208-a and a sufficient effect will not be obtained So, in this case, after the speed is detected between B and D as shown in FIG. 11c, that is, after a point D is detected, the time when a pulse 233 is generated is delayed by a predetermined time Δt. If this is done, the printing hammer 209 will come closer to the stopper 208-a during the delay time Δt and deceleration will be started in an appropriate position and thus, smooth deceleration will be accomplished as indicated by a curve 230 in FIG. 11A.
FIG. 9A is a flow chart showing the brake control procedure in the present embodiment, and FIG. 9B is a timing chart of braking operation. When a pulse is generated in the output of the pulse forming circuit 301, interruption input is effected at step S21. At step S22, +1 is effected on a pulse counter (PC) in the CPU 302. Thus, the pulse counter PC counts the frequency of generation of the sensor output pulse in the reciprocal movement of the printing hammer, as shown in FIG. 9B. At step S23, whether PC=3 is discriminated. If PC=3, advance is made to step S24, where the timer 303 is started. This is for measuring the time between B and D. Unless PC=3, advance is made to step S25, where whether PC=4 is discriminated. Unless PC=4, return is made. If PC=4, advance is made to step S26, where the timer 303 is stopped. At step S27, the content of the timer 303 is held in a register Th in the CPU 302. At step S28, by the content of the register Th, the corresponding delay time At is read out from a plurality of delay times with reference to the ROM table 400 in the CPU 302. Further, at step S29, likewise by the content of the register Th, an optimum driving current value L is read out from a plurality of driving current values with reference to the ROM table 400. In this manner, at step S30, the lapse of the delay time Δt is waited for. This can be accomplished by the CPU 302 looping a predetermined routine for the time Δt. At step S31, second driving pulse control (braking current control) as shown in FIG. 9B is effected to thereby accomplish optimum braking. | An impact type recording apparatus includes a platen for supporting a recording medium, a hammer guided for reciprocal movement between an impacting position in which it strikes against the platen and a retracted position spaced apart from the platen, energizing means producing a force for biasing the hammer from the retracted position toward the impacting position, means for detecting the position of the hammer to thereby detect the speed of the hammer, and drive control means for operating the energizing means with only one pulse to brake the hammer when the hammer is moved from the impacting position to the retracted position, and making the operation timing of the braking pulse variable in conformity with the result of the detection by the detecting means. | 1 |
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